xref: /linux/drivers/spi/spi-pl022.c (revision 0889d07f3e4b171c453b2aaf2b257f9074cdf624)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
4  *
5  * Copyright (C) 2008-2012 ST-Ericsson AB
6  * Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
7  *
8  * Author: Linus Walleij <linus.walleij@stericsson.com>
9  *
10  * Initial version inspired by:
11  *	linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
12  * Initial adoption to PL022 by:
13  *      Sachin Verma <sachin.verma@st.com>
14  */
15 
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/device.h>
19 #include <linux/ioport.h>
20 #include <linux/errno.h>
21 #include <linux/interrupt.h>
22 #include <linux/spi/spi.h>
23 #include <linux/delay.h>
24 #include <linux/clk.h>
25 #include <linux/err.h>
26 #include <linux/amba/bus.h>
27 #include <linux/amba/pl022.h>
28 #include <linux/io.h>
29 #include <linux/slab.h>
30 #include <linux/dmaengine.h>
31 #include <linux/dma-mapping.h>
32 #include <linux/scatterlist.h>
33 #include <linux/pm_runtime.h>
34 #include <linux/gpio.h>
35 #include <linux/of_gpio.h>
36 #include <linux/pinctrl/consumer.h>
37 
38 /*
39  * This macro is used to define some register default values.
40  * reg is masked with mask, the OR:ed with an (again masked)
41  * val shifted sb steps to the left.
42  */
43 #define SSP_WRITE_BITS(reg, val, mask, sb) \
44  ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))
45 
46 /*
47  * This macro is also used to define some default values.
48  * It will just shift val by sb steps to the left and mask
49  * the result with mask.
50  */
51 #define GEN_MASK_BITS(val, mask, sb) \
52  (((val)<<(sb)) & (mask))
53 
54 #define DRIVE_TX		0
55 #define DO_NOT_DRIVE_TX		1
56 
57 #define DO_NOT_QUEUE_DMA	0
58 #define QUEUE_DMA		1
59 
60 #define RX_TRANSFER		1
61 #define TX_TRANSFER		2
62 
63 /*
64  * Macros to access SSP Registers with their offsets
65  */
66 #define SSP_CR0(r)	(r + 0x000)
67 #define SSP_CR1(r)	(r + 0x004)
68 #define SSP_DR(r)	(r + 0x008)
69 #define SSP_SR(r)	(r + 0x00C)
70 #define SSP_CPSR(r)	(r + 0x010)
71 #define SSP_IMSC(r)	(r + 0x014)
72 #define SSP_RIS(r)	(r + 0x018)
73 #define SSP_MIS(r)	(r + 0x01C)
74 #define SSP_ICR(r)	(r + 0x020)
75 #define SSP_DMACR(r)	(r + 0x024)
76 #define SSP_CSR(r)	(r + 0x030) /* vendor extension */
77 #define SSP_ITCR(r)	(r + 0x080)
78 #define SSP_ITIP(r)	(r + 0x084)
79 #define SSP_ITOP(r)	(r + 0x088)
80 #define SSP_TDR(r)	(r + 0x08C)
81 
82 #define SSP_PID0(r)	(r + 0xFE0)
83 #define SSP_PID1(r)	(r + 0xFE4)
84 #define SSP_PID2(r)	(r + 0xFE8)
85 #define SSP_PID3(r)	(r + 0xFEC)
86 
87 #define SSP_CID0(r)	(r + 0xFF0)
88 #define SSP_CID1(r)	(r + 0xFF4)
89 #define SSP_CID2(r)	(r + 0xFF8)
90 #define SSP_CID3(r)	(r + 0xFFC)
91 
92 /*
93  * SSP Control Register 0  - SSP_CR0
94  */
95 #define SSP_CR0_MASK_DSS	(0x0FUL << 0)
96 #define SSP_CR0_MASK_FRF	(0x3UL << 4)
97 #define SSP_CR0_MASK_SPO	(0x1UL << 6)
98 #define SSP_CR0_MASK_SPH	(0x1UL << 7)
99 #define SSP_CR0_MASK_SCR	(0xFFUL << 8)
100 
101 /*
102  * The ST version of this block moves som bits
103  * in SSP_CR0 and extends it to 32 bits
104  */
105 #define SSP_CR0_MASK_DSS_ST	(0x1FUL << 0)
106 #define SSP_CR0_MASK_HALFDUP_ST	(0x1UL << 5)
107 #define SSP_CR0_MASK_CSS_ST	(0x1FUL << 16)
108 #define SSP_CR0_MASK_FRF_ST	(0x3UL << 21)
109 
110 /*
111  * SSP Control Register 0  - SSP_CR1
112  */
113 #define SSP_CR1_MASK_LBM	(0x1UL << 0)
114 #define SSP_CR1_MASK_SSE	(0x1UL << 1)
115 #define SSP_CR1_MASK_MS		(0x1UL << 2)
116 #define SSP_CR1_MASK_SOD	(0x1UL << 3)
117 
118 /*
119  * The ST version of this block adds some bits
120  * in SSP_CR1
121  */
122 #define SSP_CR1_MASK_RENDN_ST	(0x1UL << 4)
123 #define SSP_CR1_MASK_TENDN_ST	(0x1UL << 5)
124 #define SSP_CR1_MASK_MWAIT_ST	(0x1UL << 6)
125 #define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
126 #define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
127 /* This one is only in the PL023 variant */
128 #define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)
129 
130 /*
131  * SSP Status Register - SSP_SR
132  */
133 #define SSP_SR_MASK_TFE		(0x1UL << 0) /* Transmit FIFO empty */
134 #define SSP_SR_MASK_TNF		(0x1UL << 1) /* Transmit FIFO not full */
135 #define SSP_SR_MASK_RNE		(0x1UL << 2) /* Receive FIFO not empty */
136 #define SSP_SR_MASK_RFF		(0x1UL << 3) /* Receive FIFO full */
137 #define SSP_SR_MASK_BSY		(0x1UL << 4) /* Busy Flag */
138 
139 /*
140  * SSP Clock Prescale Register  - SSP_CPSR
141  */
142 #define SSP_CPSR_MASK_CPSDVSR	(0xFFUL << 0)
143 
144 /*
145  * SSP Interrupt Mask Set/Clear Register - SSP_IMSC
146  */
147 #define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
148 #define SSP_IMSC_MASK_RTIM  (0x1UL << 1) /* Receive timeout Interrupt mask */
149 #define SSP_IMSC_MASK_RXIM  (0x1UL << 2) /* Receive FIFO Interrupt mask */
150 #define SSP_IMSC_MASK_TXIM  (0x1UL << 3) /* Transmit FIFO Interrupt mask */
151 
152 /*
153  * SSP Raw Interrupt Status Register - SSP_RIS
154  */
155 /* Receive Overrun Raw Interrupt status */
156 #define SSP_RIS_MASK_RORRIS		(0x1UL << 0)
157 /* Receive Timeout Raw Interrupt status */
158 #define SSP_RIS_MASK_RTRIS		(0x1UL << 1)
159 /* Receive FIFO Raw Interrupt status */
160 #define SSP_RIS_MASK_RXRIS		(0x1UL << 2)
161 /* Transmit FIFO Raw Interrupt status */
162 #define SSP_RIS_MASK_TXRIS		(0x1UL << 3)
163 
164 /*
165  * SSP Masked Interrupt Status Register - SSP_MIS
166  */
167 /* Receive Overrun Masked Interrupt status */
168 #define SSP_MIS_MASK_RORMIS		(0x1UL << 0)
169 /* Receive Timeout Masked Interrupt status */
170 #define SSP_MIS_MASK_RTMIS		(0x1UL << 1)
171 /* Receive FIFO Masked Interrupt status */
172 #define SSP_MIS_MASK_RXMIS		(0x1UL << 2)
173 /* Transmit FIFO Masked Interrupt status */
174 #define SSP_MIS_MASK_TXMIS		(0x1UL << 3)
175 
176 /*
177  * SSP Interrupt Clear Register - SSP_ICR
178  */
179 /* Receive Overrun Raw Clear Interrupt bit */
180 #define SSP_ICR_MASK_RORIC		(0x1UL << 0)
181 /* Receive Timeout Clear Interrupt bit */
182 #define SSP_ICR_MASK_RTIC		(0x1UL << 1)
183 
184 /*
185  * SSP DMA Control Register - SSP_DMACR
186  */
187 /* Receive DMA Enable bit */
188 #define SSP_DMACR_MASK_RXDMAE		(0x1UL << 0)
189 /* Transmit DMA Enable bit */
190 #define SSP_DMACR_MASK_TXDMAE		(0x1UL << 1)
191 
192 /*
193  * SSP Chip Select Control Register - SSP_CSR
194  * (vendor extension)
195  */
196 #define SSP_CSR_CSVALUE_MASK		(0x1FUL << 0)
197 
198 /*
199  * SSP Integration Test control Register - SSP_ITCR
200  */
201 #define SSP_ITCR_MASK_ITEN		(0x1UL << 0)
202 #define SSP_ITCR_MASK_TESTFIFO		(0x1UL << 1)
203 
204 /*
205  * SSP Integration Test Input Register - SSP_ITIP
206  */
207 #define ITIP_MASK_SSPRXD		 (0x1UL << 0)
208 #define ITIP_MASK_SSPFSSIN		 (0x1UL << 1)
209 #define ITIP_MASK_SSPCLKIN		 (0x1UL << 2)
210 #define ITIP_MASK_RXDMAC		 (0x1UL << 3)
211 #define ITIP_MASK_TXDMAC		 (0x1UL << 4)
212 #define ITIP_MASK_SSPTXDIN		 (0x1UL << 5)
213 
214 /*
215  * SSP Integration Test output Register - SSP_ITOP
216  */
217 #define ITOP_MASK_SSPTXD		 (0x1UL << 0)
218 #define ITOP_MASK_SSPFSSOUT		 (0x1UL << 1)
219 #define ITOP_MASK_SSPCLKOUT		 (0x1UL << 2)
220 #define ITOP_MASK_SSPOEn		 (0x1UL << 3)
221 #define ITOP_MASK_SSPCTLOEn		 (0x1UL << 4)
222 #define ITOP_MASK_RORINTR		 (0x1UL << 5)
223 #define ITOP_MASK_RTINTR		 (0x1UL << 6)
224 #define ITOP_MASK_RXINTR		 (0x1UL << 7)
225 #define ITOP_MASK_TXINTR		 (0x1UL << 8)
226 #define ITOP_MASK_INTR			 (0x1UL << 9)
227 #define ITOP_MASK_RXDMABREQ		 (0x1UL << 10)
228 #define ITOP_MASK_RXDMASREQ		 (0x1UL << 11)
229 #define ITOP_MASK_TXDMABREQ		 (0x1UL << 12)
230 #define ITOP_MASK_TXDMASREQ		 (0x1UL << 13)
231 
232 /*
233  * SSP Test Data Register - SSP_TDR
234  */
235 #define TDR_MASK_TESTDATA		(0xFFFFFFFF)
236 
237 /*
238  * Message State
239  * we use the spi_message.state (void *) pointer to
240  * hold a single state value, that's why all this
241  * (void *) casting is done here.
242  */
243 #define STATE_START			((void *) 0)
244 #define STATE_RUNNING			((void *) 1)
245 #define STATE_DONE			((void *) 2)
246 #define STATE_ERROR			((void *) -1)
247 #define STATE_TIMEOUT			((void *) -2)
248 
249 /*
250  * SSP State - Whether Enabled or Disabled
251  */
252 #define SSP_DISABLED			(0)
253 #define SSP_ENABLED			(1)
254 
255 /*
256  * SSP DMA State - Whether DMA Enabled or Disabled
257  */
258 #define SSP_DMA_DISABLED		(0)
259 #define SSP_DMA_ENABLED			(1)
260 
261 /*
262  * SSP Clock Defaults
263  */
264 #define SSP_DEFAULT_CLKRATE 0x2
265 #define SSP_DEFAULT_PRESCALE 0x40
266 
267 /*
268  * SSP Clock Parameter ranges
269  */
270 #define CPSDVR_MIN 0x02
271 #define CPSDVR_MAX 0xFE
272 #define SCR_MIN 0x00
273 #define SCR_MAX 0xFF
274 
275 /*
276  * SSP Interrupt related Macros
277  */
278 #define DEFAULT_SSP_REG_IMSC  0x0UL
279 #define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
280 #define ENABLE_ALL_INTERRUPTS ( \
281 	SSP_IMSC_MASK_RORIM | \
282 	SSP_IMSC_MASK_RTIM | \
283 	SSP_IMSC_MASK_RXIM | \
284 	SSP_IMSC_MASK_TXIM \
285 )
286 
287 #define CLEAR_ALL_INTERRUPTS  0x3
288 
289 #define SPI_POLLING_TIMEOUT 1000
290 
291 /*
292  * The type of reading going on on this chip
293  */
294 enum ssp_reading {
295 	READING_NULL,
296 	READING_U8,
297 	READING_U16,
298 	READING_U32
299 };
300 
301 /**
302  * The type of writing going on on this chip
303  */
304 enum ssp_writing {
305 	WRITING_NULL,
306 	WRITING_U8,
307 	WRITING_U16,
308 	WRITING_U32
309 };
310 
311 /**
312  * struct vendor_data - vendor-specific config parameters
313  * for PL022 derivates
314  * @fifodepth: depth of FIFOs (both)
315  * @max_bpw: maximum number of bits per word
316  * @unidir: supports unidirection transfers
317  * @extended_cr: 32 bit wide control register 0 with extra
318  * features and extra features in CR1 as found in the ST variants
319  * @pl023: supports a subset of the ST extensions called "PL023"
320  * @internal_cs_ctrl: supports chip select control register
321  */
322 struct vendor_data {
323 	int fifodepth;
324 	int max_bpw;
325 	bool unidir;
326 	bool extended_cr;
327 	bool pl023;
328 	bool loopback;
329 	bool internal_cs_ctrl;
330 };
331 
332 /**
333  * struct pl022 - This is the private SSP driver data structure
334  * @adev: AMBA device model hookup
335  * @vendor: vendor data for the IP block
336  * @phybase: the physical memory where the SSP device resides
337  * @virtbase: the virtual memory where the SSP is mapped
338  * @clk: outgoing clock "SPICLK" for the SPI bus
339  * @master: SPI framework hookup
340  * @master_info: controller-specific data from machine setup
341  * @pump_transfers: Tasklet used in Interrupt Transfer mode
342  * @cur_msg: Pointer to current spi_message being processed
343  * @cur_transfer: Pointer to current spi_transfer
344  * @cur_chip: pointer to current clients chip(assigned from controller_state)
345  * @next_msg_cs_active: the next message in the queue has been examined
346  *  and it was found that it uses the same chip select as the previous
347  *  message, so we left it active after the previous transfer, and it's
348  *  active already.
349  * @tx: current position in TX buffer to be read
350  * @tx_end: end position in TX buffer to be read
351  * @rx: current position in RX buffer to be written
352  * @rx_end: end position in RX buffer to be written
353  * @read: the type of read currently going on
354  * @write: the type of write currently going on
355  * @exp_fifo_level: expected FIFO level
356  * @dma_rx_channel: optional channel for RX DMA
357  * @dma_tx_channel: optional channel for TX DMA
358  * @sgt_rx: scattertable for the RX transfer
359  * @sgt_tx: scattertable for the TX transfer
360  * @dummypage: a dummy page used for driving data on the bus with DMA
361  * @cur_cs: current chip select (gpio)
362  * @chipselects: list of chipselects (gpios)
363  */
364 struct pl022 {
365 	struct amba_device		*adev;
366 	struct vendor_data		*vendor;
367 	resource_size_t			phybase;
368 	void __iomem			*virtbase;
369 	struct clk			*clk;
370 	struct spi_master		*master;
371 	struct pl022_ssp_controller	*master_info;
372 	/* Message per-transfer pump */
373 	struct tasklet_struct		pump_transfers;
374 	struct spi_message		*cur_msg;
375 	struct spi_transfer		*cur_transfer;
376 	struct chip_data		*cur_chip;
377 	bool				next_msg_cs_active;
378 	void				*tx;
379 	void				*tx_end;
380 	void				*rx;
381 	void				*rx_end;
382 	enum ssp_reading		read;
383 	enum ssp_writing		write;
384 	u32				exp_fifo_level;
385 	enum ssp_rx_level_trig		rx_lev_trig;
386 	enum ssp_tx_level_trig		tx_lev_trig;
387 	/* DMA settings */
388 #ifdef CONFIG_DMA_ENGINE
389 	struct dma_chan			*dma_rx_channel;
390 	struct dma_chan			*dma_tx_channel;
391 	struct sg_table			sgt_rx;
392 	struct sg_table			sgt_tx;
393 	char				*dummypage;
394 	bool				dma_running;
395 #endif
396 	int cur_cs;
397 	int *chipselects;
398 };
399 
400 /**
401  * struct chip_data - To maintain runtime state of SSP for each client chip
402  * @cr0: Value of control register CR0 of SSP - on later ST variants this
403  *       register is 32 bits wide rather than just 16
404  * @cr1: Value of control register CR1 of SSP
405  * @dmacr: Value of DMA control Register of SSP
406  * @cpsr: Value of Clock prescale register
407  * @n_bytes: how many bytes(power of 2) reqd for a given data width of client
408  * @enable_dma: Whether to enable DMA or not
409  * @read: function ptr to be used to read when doing xfer for this chip
410  * @write: function ptr to be used to write when doing xfer for this chip
411  * @cs_control: chip select callback provided by chip
412  * @xfer_type: polling/interrupt/DMA
413  *
414  * Runtime state of the SSP controller, maintained per chip,
415  * This would be set according to the current message that would be served
416  */
417 struct chip_data {
418 	u32 cr0;
419 	u16 cr1;
420 	u16 dmacr;
421 	u16 cpsr;
422 	u8 n_bytes;
423 	bool enable_dma;
424 	enum ssp_reading read;
425 	enum ssp_writing write;
426 	void (*cs_control) (u32 command);
427 	int xfer_type;
428 };
429 
430 /**
431  * null_cs_control - Dummy chip select function
432  * @command: select/delect the chip
433  *
434  * If no chip select function is provided by client this is used as dummy
435  * chip select
436  */
437 static void null_cs_control(u32 command)
438 {
439 	pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
440 }
441 
442 /**
443  * internal_cs_control - Control chip select signals via SSP_CSR.
444  * @pl022: SSP driver private data structure
445  * @command: select/delect the chip
446  *
447  * Used on controller with internal chip select control via SSP_CSR register
448  * (vendor extension). Each of the 5 LSB in the register controls one chip
449  * select signal.
450  */
451 static void internal_cs_control(struct pl022 *pl022, u32 command)
452 {
453 	u32 tmp;
454 
455 	tmp = readw(SSP_CSR(pl022->virtbase));
456 	if (command == SSP_CHIP_SELECT)
457 		tmp &= ~BIT(pl022->cur_cs);
458 	else
459 		tmp |= BIT(pl022->cur_cs);
460 	writew(tmp, SSP_CSR(pl022->virtbase));
461 }
462 
463 static void pl022_cs_control(struct pl022 *pl022, u32 command)
464 {
465 	if (pl022->vendor->internal_cs_ctrl)
466 		internal_cs_control(pl022, command);
467 	else if (gpio_is_valid(pl022->cur_cs))
468 		gpio_set_value(pl022->cur_cs, command);
469 	else
470 		pl022->cur_chip->cs_control(command);
471 }
472 
473 /**
474  * giveback - current spi_message is over, schedule next message and call
475  * callback of this message. Assumes that caller already
476  * set message->status; dma and pio irqs are blocked
477  * @pl022: SSP driver private data structure
478  */
479 static void giveback(struct pl022 *pl022)
480 {
481 	struct spi_transfer *last_transfer;
482 	pl022->next_msg_cs_active = false;
483 
484 	last_transfer = list_last_entry(&pl022->cur_msg->transfers,
485 					struct spi_transfer, transfer_list);
486 
487 	/* Delay if requested before any change in chip select */
488 	if (last_transfer->delay_usecs)
489 		/*
490 		 * FIXME: This runs in interrupt context.
491 		 * Is this really smart?
492 		 */
493 		udelay(last_transfer->delay_usecs);
494 
495 	if (!last_transfer->cs_change) {
496 		struct spi_message *next_msg;
497 
498 		/*
499 		 * cs_change was not set. We can keep the chip select
500 		 * enabled if there is message in the queue and it is
501 		 * for the same spi device.
502 		 *
503 		 * We cannot postpone this until pump_messages, because
504 		 * after calling msg->complete (below) the driver that
505 		 * sent the current message could be unloaded, which
506 		 * could invalidate the cs_control() callback...
507 		 */
508 		/* get a pointer to the next message, if any */
509 		next_msg = spi_get_next_queued_message(pl022->master);
510 
511 		/*
512 		 * see if the next and current messages point
513 		 * to the same spi device.
514 		 */
515 		if (next_msg && next_msg->spi != pl022->cur_msg->spi)
516 			next_msg = NULL;
517 		if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
518 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
519 		else
520 			pl022->next_msg_cs_active = true;
521 
522 	}
523 
524 	pl022->cur_msg = NULL;
525 	pl022->cur_transfer = NULL;
526 	pl022->cur_chip = NULL;
527 
528 	/* disable the SPI/SSP operation */
529 	writew((readw(SSP_CR1(pl022->virtbase)) &
530 		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
531 
532 	spi_finalize_current_message(pl022->master);
533 }
534 
535 /**
536  * flush - flush the FIFO to reach a clean state
537  * @pl022: SSP driver private data structure
538  */
539 static int flush(struct pl022 *pl022)
540 {
541 	unsigned long limit = loops_per_jiffy << 1;
542 
543 	dev_dbg(&pl022->adev->dev, "flush\n");
544 	do {
545 		while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
546 			readw(SSP_DR(pl022->virtbase));
547 	} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
548 
549 	pl022->exp_fifo_level = 0;
550 
551 	return limit;
552 }
553 
554 /**
555  * restore_state - Load configuration of current chip
556  * @pl022: SSP driver private data structure
557  */
558 static void restore_state(struct pl022 *pl022)
559 {
560 	struct chip_data *chip = pl022->cur_chip;
561 
562 	if (pl022->vendor->extended_cr)
563 		writel(chip->cr0, SSP_CR0(pl022->virtbase));
564 	else
565 		writew(chip->cr0, SSP_CR0(pl022->virtbase));
566 	writew(chip->cr1, SSP_CR1(pl022->virtbase));
567 	writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
568 	writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
569 	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
570 	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
571 }
572 
573 /*
574  * Default SSP Register Values
575  */
576 #define DEFAULT_SSP_REG_CR0 ( \
577 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0)	| \
578 	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
579 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
580 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
581 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
582 )
583 
584 /* ST versions have slightly different bit layout */
585 #define DEFAULT_SSP_REG_CR0_ST ( \
586 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
587 	GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
588 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
589 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
590 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
591 	GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16)	| \
592 	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
593 )
594 
595 /* The PL023 version is slightly different again */
596 #define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
597 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
598 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
599 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
600 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
601 )
602 
603 #define DEFAULT_SSP_REG_CR1 ( \
604 	GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
605 	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
606 	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
607 	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
608 )
609 
610 /* ST versions extend this register to use all 16 bits */
611 #define DEFAULT_SSP_REG_CR1_ST ( \
612 	DEFAULT_SSP_REG_CR1 | \
613 	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
614 	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
615 	GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
616 	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
617 	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
618 )
619 
620 /*
621  * The PL023 variant has further differences: no loopback mode, no microwire
622  * support, and a new clock feedback delay setting.
623  */
624 #define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
625 	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
626 	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
627 	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
628 	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
629 	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
630 	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
631 	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
632 	GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
633 )
634 
635 #define DEFAULT_SSP_REG_CPSR ( \
636 	GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
637 )
638 
639 #define DEFAULT_SSP_REG_DMACR (\
640 	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
641 	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
642 )
643 
644 /**
645  * load_ssp_default_config - Load default configuration for SSP
646  * @pl022: SSP driver private data structure
647  */
648 static void load_ssp_default_config(struct pl022 *pl022)
649 {
650 	if (pl022->vendor->pl023) {
651 		writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
652 		writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
653 	} else if (pl022->vendor->extended_cr) {
654 		writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
655 		writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
656 	} else {
657 		writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
658 		writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
659 	}
660 	writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
661 	writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
662 	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
663 	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
664 }
665 
666 /**
667  * This will write to TX and read from RX according to the parameters
668  * set in pl022.
669  */
670 static void readwriter(struct pl022 *pl022)
671 {
672 
673 	/*
674 	 * The FIFO depth is different between primecell variants.
675 	 * I believe filling in too much in the FIFO might cause
676 	 * errons in 8bit wide transfers on ARM variants (just 8 words
677 	 * FIFO, means only 8x8 = 64 bits in FIFO) at least.
678 	 *
679 	 * To prevent this issue, the TX FIFO is only filled to the
680 	 * unused RX FIFO fill length, regardless of what the TX
681 	 * FIFO status flag indicates.
682 	 */
683 	dev_dbg(&pl022->adev->dev,
684 		"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
685 		__func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
686 
687 	/* Read as much as you can */
688 	while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
689 	       && (pl022->rx < pl022->rx_end)) {
690 		switch (pl022->read) {
691 		case READING_NULL:
692 			readw(SSP_DR(pl022->virtbase));
693 			break;
694 		case READING_U8:
695 			*(u8 *) (pl022->rx) =
696 				readw(SSP_DR(pl022->virtbase)) & 0xFFU;
697 			break;
698 		case READING_U16:
699 			*(u16 *) (pl022->rx) =
700 				(u16) readw(SSP_DR(pl022->virtbase));
701 			break;
702 		case READING_U32:
703 			*(u32 *) (pl022->rx) =
704 				readl(SSP_DR(pl022->virtbase));
705 			break;
706 		}
707 		pl022->rx += (pl022->cur_chip->n_bytes);
708 		pl022->exp_fifo_level--;
709 	}
710 	/*
711 	 * Write as much as possible up to the RX FIFO size
712 	 */
713 	while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
714 	       && (pl022->tx < pl022->tx_end)) {
715 		switch (pl022->write) {
716 		case WRITING_NULL:
717 			writew(0x0, SSP_DR(pl022->virtbase));
718 			break;
719 		case WRITING_U8:
720 			writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
721 			break;
722 		case WRITING_U16:
723 			writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
724 			break;
725 		case WRITING_U32:
726 			writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
727 			break;
728 		}
729 		pl022->tx += (pl022->cur_chip->n_bytes);
730 		pl022->exp_fifo_level++;
731 		/*
732 		 * This inner reader takes care of things appearing in the RX
733 		 * FIFO as we're transmitting. This will happen a lot since the
734 		 * clock starts running when you put things into the TX FIFO,
735 		 * and then things are continuously clocked into the RX FIFO.
736 		 */
737 		while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
738 		       && (pl022->rx < pl022->rx_end)) {
739 			switch (pl022->read) {
740 			case READING_NULL:
741 				readw(SSP_DR(pl022->virtbase));
742 				break;
743 			case READING_U8:
744 				*(u8 *) (pl022->rx) =
745 					readw(SSP_DR(pl022->virtbase)) & 0xFFU;
746 				break;
747 			case READING_U16:
748 				*(u16 *) (pl022->rx) =
749 					(u16) readw(SSP_DR(pl022->virtbase));
750 				break;
751 			case READING_U32:
752 				*(u32 *) (pl022->rx) =
753 					readl(SSP_DR(pl022->virtbase));
754 				break;
755 			}
756 			pl022->rx += (pl022->cur_chip->n_bytes);
757 			pl022->exp_fifo_level--;
758 		}
759 	}
760 	/*
761 	 * When we exit here the TX FIFO should be full and the RX FIFO
762 	 * should be empty
763 	 */
764 }
765 
766 /**
767  * next_transfer - Move to the Next transfer in the current spi message
768  * @pl022: SSP driver private data structure
769  *
770  * This function moves though the linked list of spi transfers in the
771  * current spi message and returns with the state of current spi
772  * message i.e whether its last transfer is done(STATE_DONE) or
773  * Next transfer is ready(STATE_RUNNING)
774  */
775 static void *next_transfer(struct pl022 *pl022)
776 {
777 	struct spi_message *msg = pl022->cur_msg;
778 	struct spi_transfer *trans = pl022->cur_transfer;
779 
780 	/* Move to next transfer */
781 	if (trans->transfer_list.next != &msg->transfers) {
782 		pl022->cur_transfer =
783 		    list_entry(trans->transfer_list.next,
784 			       struct spi_transfer, transfer_list);
785 		return STATE_RUNNING;
786 	}
787 	return STATE_DONE;
788 }
789 
790 /*
791  * This DMA functionality is only compiled in if we have
792  * access to the generic DMA devices/DMA engine.
793  */
794 #ifdef CONFIG_DMA_ENGINE
795 static void unmap_free_dma_scatter(struct pl022 *pl022)
796 {
797 	/* Unmap and free the SG tables */
798 	dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
799 		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
800 	dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
801 		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
802 	sg_free_table(&pl022->sgt_rx);
803 	sg_free_table(&pl022->sgt_tx);
804 }
805 
806 static void dma_callback(void *data)
807 {
808 	struct pl022 *pl022 = data;
809 	struct spi_message *msg = pl022->cur_msg;
810 
811 	BUG_ON(!pl022->sgt_rx.sgl);
812 
813 #ifdef VERBOSE_DEBUG
814 	/*
815 	 * Optionally dump out buffers to inspect contents, this is
816 	 * good if you want to convince yourself that the loopback
817 	 * read/write contents are the same, when adopting to a new
818 	 * DMA engine.
819 	 */
820 	{
821 		struct scatterlist *sg;
822 		unsigned int i;
823 
824 		dma_sync_sg_for_cpu(&pl022->adev->dev,
825 				    pl022->sgt_rx.sgl,
826 				    pl022->sgt_rx.nents,
827 				    DMA_FROM_DEVICE);
828 
829 		for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
830 			dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
831 			print_hex_dump(KERN_ERR, "SPI RX: ",
832 				       DUMP_PREFIX_OFFSET,
833 				       16,
834 				       1,
835 				       sg_virt(sg),
836 				       sg_dma_len(sg),
837 				       1);
838 		}
839 		for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
840 			dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
841 			print_hex_dump(KERN_ERR, "SPI TX: ",
842 				       DUMP_PREFIX_OFFSET,
843 				       16,
844 				       1,
845 				       sg_virt(sg),
846 				       sg_dma_len(sg),
847 				       1);
848 		}
849 	}
850 #endif
851 
852 	unmap_free_dma_scatter(pl022);
853 
854 	/* Update total bytes transferred */
855 	msg->actual_length += pl022->cur_transfer->len;
856 	/* Move to next transfer */
857 	msg->state = next_transfer(pl022);
858 	if (msg->state != STATE_DONE && pl022->cur_transfer->cs_change)
859 		pl022_cs_control(pl022, SSP_CHIP_DESELECT);
860 	tasklet_schedule(&pl022->pump_transfers);
861 }
862 
863 static void setup_dma_scatter(struct pl022 *pl022,
864 			      void *buffer,
865 			      unsigned int length,
866 			      struct sg_table *sgtab)
867 {
868 	struct scatterlist *sg;
869 	int bytesleft = length;
870 	void *bufp = buffer;
871 	int mapbytes;
872 	int i;
873 
874 	if (buffer) {
875 		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
876 			/*
877 			 * If there are less bytes left than what fits
878 			 * in the current page (plus page alignment offset)
879 			 * we just feed in this, else we stuff in as much
880 			 * as we can.
881 			 */
882 			if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
883 				mapbytes = bytesleft;
884 			else
885 				mapbytes = PAGE_SIZE - offset_in_page(bufp);
886 			sg_set_page(sg, virt_to_page(bufp),
887 				    mapbytes, offset_in_page(bufp));
888 			bufp += mapbytes;
889 			bytesleft -= mapbytes;
890 			dev_dbg(&pl022->adev->dev,
891 				"set RX/TX target page @ %p, %d bytes, %d left\n",
892 				bufp, mapbytes, bytesleft);
893 		}
894 	} else {
895 		/* Map the dummy buffer on every page */
896 		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
897 			if (bytesleft < PAGE_SIZE)
898 				mapbytes = bytesleft;
899 			else
900 				mapbytes = PAGE_SIZE;
901 			sg_set_page(sg, virt_to_page(pl022->dummypage),
902 				    mapbytes, 0);
903 			bytesleft -= mapbytes;
904 			dev_dbg(&pl022->adev->dev,
905 				"set RX/TX to dummy page %d bytes, %d left\n",
906 				mapbytes, bytesleft);
907 
908 		}
909 	}
910 	BUG_ON(bytesleft);
911 }
912 
913 /**
914  * configure_dma - configures the channels for the next transfer
915  * @pl022: SSP driver's private data structure
916  */
917 static int configure_dma(struct pl022 *pl022)
918 {
919 	struct dma_slave_config rx_conf = {
920 		.src_addr = SSP_DR(pl022->phybase),
921 		.direction = DMA_DEV_TO_MEM,
922 		.device_fc = false,
923 	};
924 	struct dma_slave_config tx_conf = {
925 		.dst_addr = SSP_DR(pl022->phybase),
926 		.direction = DMA_MEM_TO_DEV,
927 		.device_fc = false,
928 	};
929 	unsigned int pages;
930 	int ret;
931 	int rx_sglen, tx_sglen;
932 	struct dma_chan *rxchan = pl022->dma_rx_channel;
933 	struct dma_chan *txchan = pl022->dma_tx_channel;
934 	struct dma_async_tx_descriptor *rxdesc;
935 	struct dma_async_tx_descriptor *txdesc;
936 
937 	/* Check that the channels are available */
938 	if (!rxchan || !txchan)
939 		return -ENODEV;
940 
941 	/*
942 	 * If supplied, the DMA burstsize should equal the FIFO trigger level.
943 	 * Notice that the DMA engine uses one-to-one mapping. Since we can
944 	 * not trigger on 2 elements this needs explicit mapping rather than
945 	 * calculation.
946 	 */
947 	switch (pl022->rx_lev_trig) {
948 	case SSP_RX_1_OR_MORE_ELEM:
949 		rx_conf.src_maxburst = 1;
950 		break;
951 	case SSP_RX_4_OR_MORE_ELEM:
952 		rx_conf.src_maxburst = 4;
953 		break;
954 	case SSP_RX_8_OR_MORE_ELEM:
955 		rx_conf.src_maxburst = 8;
956 		break;
957 	case SSP_RX_16_OR_MORE_ELEM:
958 		rx_conf.src_maxburst = 16;
959 		break;
960 	case SSP_RX_32_OR_MORE_ELEM:
961 		rx_conf.src_maxburst = 32;
962 		break;
963 	default:
964 		rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
965 		break;
966 	}
967 
968 	switch (pl022->tx_lev_trig) {
969 	case SSP_TX_1_OR_MORE_EMPTY_LOC:
970 		tx_conf.dst_maxburst = 1;
971 		break;
972 	case SSP_TX_4_OR_MORE_EMPTY_LOC:
973 		tx_conf.dst_maxburst = 4;
974 		break;
975 	case SSP_TX_8_OR_MORE_EMPTY_LOC:
976 		tx_conf.dst_maxburst = 8;
977 		break;
978 	case SSP_TX_16_OR_MORE_EMPTY_LOC:
979 		tx_conf.dst_maxburst = 16;
980 		break;
981 	case SSP_TX_32_OR_MORE_EMPTY_LOC:
982 		tx_conf.dst_maxburst = 32;
983 		break;
984 	default:
985 		tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
986 		break;
987 	}
988 
989 	switch (pl022->read) {
990 	case READING_NULL:
991 		/* Use the same as for writing */
992 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
993 		break;
994 	case READING_U8:
995 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
996 		break;
997 	case READING_U16:
998 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
999 		break;
1000 	case READING_U32:
1001 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1002 		break;
1003 	}
1004 
1005 	switch (pl022->write) {
1006 	case WRITING_NULL:
1007 		/* Use the same as for reading */
1008 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
1009 		break;
1010 	case WRITING_U8:
1011 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1012 		break;
1013 	case WRITING_U16:
1014 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1015 		break;
1016 	case WRITING_U32:
1017 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1018 		break;
1019 	}
1020 
1021 	/* SPI pecularity: we need to read and write the same width */
1022 	if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1023 		rx_conf.src_addr_width = tx_conf.dst_addr_width;
1024 	if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1025 		tx_conf.dst_addr_width = rx_conf.src_addr_width;
1026 	BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
1027 
1028 	dmaengine_slave_config(rxchan, &rx_conf);
1029 	dmaengine_slave_config(txchan, &tx_conf);
1030 
1031 	/* Create sglists for the transfers */
1032 	pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
1033 	dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
1034 
1035 	ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
1036 	if (ret)
1037 		goto err_alloc_rx_sg;
1038 
1039 	ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
1040 	if (ret)
1041 		goto err_alloc_tx_sg;
1042 
1043 	/* Fill in the scatterlists for the RX+TX buffers */
1044 	setup_dma_scatter(pl022, pl022->rx,
1045 			  pl022->cur_transfer->len, &pl022->sgt_rx);
1046 	setup_dma_scatter(pl022, pl022->tx,
1047 			  pl022->cur_transfer->len, &pl022->sgt_tx);
1048 
1049 	/* Map DMA buffers */
1050 	rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1051 			   pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1052 	if (!rx_sglen)
1053 		goto err_rx_sgmap;
1054 
1055 	tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1056 			   pl022->sgt_tx.nents, DMA_TO_DEVICE);
1057 	if (!tx_sglen)
1058 		goto err_tx_sgmap;
1059 
1060 	/* Send both scatterlists */
1061 	rxdesc = dmaengine_prep_slave_sg(rxchan,
1062 				      pl022->sgt_rx.sgl,
1063 				      rx_sglen,
1064 				      DMA_DEV_TO_MEM,
1065 				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1066 	if (!rxdesc)
1067 		goto err_rxdesc;
1068 
1069 	txdesc = dmaengine_prep_slave_sg(txchan,
1070 				      pl022->sgt_tx.sgl,
1071 				      tx_sglen,
1072 				      DMA_MEM_TO_DEV,
1073 				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1074 	if (!txdesc)
1075 		goto err_txdesc;
1076 
1077 	/* Put the callback on the RX transfer only, that should finish last */
1078 	rxdesc->callback = dma_callback;
1079 	rxdesc->callback_param = pl022;
1080 
1081 	/* Submit and fire RX and TX with TX last so we're ready to read! */
1082 	dmaengine_submit(rxdesc);
1083 	dmaengine_submit(txdesc);
1084 	dma_async_issue_pending(rxchan);
1085 	dma_async_issue_pending(txchan);
1086 	pl022->dma_running = true;
1087 
1088 	return 0;
1089 
1090 err_txdesc:
1091 	dmaengine_terminate_all(txchan);
1092 err_rxdesc:
1093 	dmaengine_terminate_all(rxchan);
1094 	dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1095 		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
1096 err_tx_sgmap:
1097 	dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1098 		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1099 err_rx_sgmap:
1100 	sg_free_table(&pl022->sgt_tx);
1101 err_alloc_tx_sg:
1102 	sg_free_table(&pl022->sgt_rx);
1103 err_alloc_rx_sg:
1104 	return -ENOMEM;
1105 }
1106 
1107 static int pl022_dma_probe(struct pl022 *pl022)
1108 {
1109 	dma_cap_mask_t mask;
1110 
1111 	/* Try to acquire a generic DMA engine slave channel */
1112 	dma_cap_zero(mask);
1113 	dma_cap_set(DMA_SLAVE, mask);
1114 	/*
1115 	 * We need both RX and TX channels to do DMA, else do none
1116 	 * of them.
1117 	 */
1118 	pl022->dma_rx_channel = dma_request_channel(mask,
1119 					    pl022->master_info->dma_filter,
1120 					    pl022->master_info->dma_rx_param);
1121 	if (!pl022->dma_rx_channel) {
1122 		dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
1123 		goto err_no_rxchan;
1124 	}
1125 
1126 	pl022->dma_tx_channel = dma_request_channel(mask,
1127 					    pl022->master_info->dma_filter,
1128 					    pl022->master_info->dma_tx_param);
1129 	if (!pl022->dma_tx_channel) {
1130 		dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
1131 		goto err_no_txchan;
1132 	}
1133 
1134 	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1135 	if (!pl022->dummypage)
1136 		goto err_no_dummypage;
1137 
1138 	dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
1139 		 dma_chan_name(pl022->dma_rx_channel),
1140 		 dma_chan_name(pl022->dma_tx_channel));
1141 
1142 	return 0;
1143 
1144 err_no_dummypage:
1145 	dma_release_channel(pl022->dma_tx_channel);
1146 err_no_txchan:
1147 	dma_release_channel(pl022->dma_rx_channel);
1148 	pl022->dma_rx_channel = NULL;
1149 err_no_rxchan:
1150 	dev_err(&pl022->adev->dev,
1151 			"Failed to work in dma mode, work without dma!\n");
1152 	return -ENODEV;
1153 }
1154 
1155 static int pl022_dma_autoprobe(struct pl022 *pl022)
1156 {
1157 	struct device *dev = &pl022->adev->dev;
1158 	struct dma_chan *chan;
1159 	int err;
1160 
1161 	/* automatically configure DMA channels from platform, normally using DT */
1162 	chan = dma_request_slave_channel_reason(dev, "rx");
1163 	if (IS_ERR(chan)) {
1164 		err = PTR_ERR(chan);
1165 		goto err_no_rxchan;
1166 	}
1167 
1168 	pl022->dma_rx_channel = chan;
1169 
1170 	chan = dma_request_slave_channel_reason(dev, "tx");
1171 	if (IS_ERR(chan)) {
1172 		err = PTR_ERR(chan);
1173 		goto err_no_txchan;
1174 	}
1175 
1176 	pl022->dma_tx_channel = chan;
1177 
1178 	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1179 	if (!pl022->dummypage) {
1180 		err = -ENOMEM;
1181 		goto err_no_dummypage;
1182 	}
1183 
1184 	return 0;
1185 
1186 err_no_dummypage:
1187 	dma_release_channel(pl022->dma_tx_channel);
1188 	pl022->dma_tx_channel = NULL;
1189 err_no_txchan:
1190 	dma_release_channel(pl022->dma_rx_channel);
1191 	pl022->dma_rx_channel = NULL;
1192 err_no_rxchan:
1193 	return err;
1194 }
1195 
1196 static void terminate_dma(struct pl022 *pl022)
1197 {
1198 	struct dma_chan *rxchan = pl022->dma_rx_channel;
1199 	struct dma_chan *txchan = pl022->dma_tx_channel;
1200 
1201 	dmaengine_terminate_all(rxchan);
1202 	dmaengine_terminate_all(txchan);
1203 	unmap_free_dma_scatter(pl022);
1204 	pl022->dma_running = false;
1205 }
1206 
1207 static void pl022_dma_remove(struct pl022 *pl022)
1208 {
1209 	if (pl022->dma_running)
1210 		terminate_dma(pl022);
1211 	if (pl022->dma_tx_channel)
1212 		dma_release_channel(pl022->dma_tx_channel);
1213 	if (pl022->dma_rx_channel)
1214 		dma_release_channel(pl022->dma_rx_channel);
1215 	kfree(pl022->dummypage);
1216 }
1217 
1218 #else
1219 static inline int configure_dma(struct pl022 *pl022)
1220 {
1221 	return -ENODEV;
1222 }
1223 
1224 static inline int pl022_dma_autoprobe(struct pl022 *pl022)
1225 {
1226 	return 0;
1227 }
1228 
1229 static inline int pl022_dma_probe(struct pl022 *pl022)
1230 {
1231 	return 0;
1232 }
1233 
1234 static inline void pl022_dma_remove(struct pl022 *pl022)
1235 {
1236 }
1237 #endif
1238 
1239 /**
1240  * pl022_interrupt_handler - Interrupt handler for SSP controller
1241  *
1242  * This function handles interrupts generated for an interrupt based transfer.
1243  * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
1244  * current message's state as STATE_ERROR and schedule the tasklet
1245  * pump_transfers which will do the postprocessing of the current message by
1246  * calling giveback(). Otherwise it reads data from RX FIFO till there is no
1247  * more data, and writes data in TX FIFO till it is not full. If we complete
1248  * the transfer we move to the next transfer and schedule the tasklet.
1249  */
1250 static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
1251 {
1252 	struct pl022 *pl022 = dev_id;
1253 	struct spi_message *msg = pl022->cur_msg;
1254 	u16 irq_status = 0;
1255 
1256 	if (unlikely(!msg)) {
1257 		dev_err(&pl022->adev->dev,
1258 			"bad message state in interrupt handler");
1259 		/* Never fail */
1260 		return IRQ_HANDLED;
1261 	}
1262 
1263 	/* Read the Interrupt Status Register */
1264 	irq_status = readw(SSP_MIS(pl022->virtbase));
1265 
1266 	if (unlikely(!irq_status))
1267 		return IRQ_NONE;
1268 
1269 	/*
1270 	 * This handles the FIFO interrupts, the timeout
1271 	 * interrupts are flatly ignored, they cannot be
1272 	 * trusted.
1273 	 */
1274 	if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
1275 		/*
1276 		 * Overrun interrupt - bail out since our Data has been
1277 		 * corrupted
1278 		 */
1279 		dev_err(&pl022->adev->dev, "FIFO overrun\n");
1280 		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
1281 			dev_err(&pl022->adev->dev,
1282 				"RXFIFO is full\n");
1283 
1284 		/*
1285 		 * Disable and clear interrupts, disable SSP,
1286 		 * mark message with bad status so it can be
1287 		 * retried.
1288 		 */
1289 		writew(DISABLE_ALL_INTERRUPTS,
1290 		       SSP_IMSC(pl022->virtbase));
1291 		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1292 		writew((readw(SSP_CR1(pl022->virtbase)) &
1293 			(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1294 		msg->state = STATE_ERROR;
1295 
1296 		/* Schedule message queue handler */
1297 		tasklet_schedule(&pl022->pump_transfers);
1298 		return IRQ_HANDLED;
1299 	}
1300 
1301 	readwriter(pl022);
1302 
1303 	if (pl022->tx == pl022->tx_end) {
1304 		/* Disable Transmit interrupt, enable receive interrupt */
1305 		writew((readw(SSP_IMSC(pl022->virtbase)) &
1306 		       ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
1307 		       SSP_IMSC(pl022->virtbase));
1308 	}
1309 
1310 	/*
1311 	 * Since all transactions must write as much as shall be read,
1312 	 * we can conclude the entire transaction once RX is complete.
1313 	 * At this point, all TX will always be finished.
1314 	 */
1315 	if (pl022->rx >= pl022->rx_end) {
1316 		writew(DISABLE_ALL_INTERRUPTS,
1317 		       SSP_IMSC(pl022->virtbase));
1318 		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1319 		if (unlikely(pl022->rx > pl022->rx_end)) {
1320 			dev_warn(&pl022->adev->dev, "read %u surplus "
1321 				 "bytes (did you request an odd "
1322 				 "number of bytes on a 16bit bus?)\n",
1323 				 (u32) (pl022->rx - pl022->rx_end));
1324 		}
1325 		/* Update total bytes transferred */
1326 		msg->actual_length += pl022->cur_transfer->len;
1327 		/* Move to next transfer */
1328 		msg->state = next_transfer(pl022);
1329 		if (msg->state != STATE_DONE && pl022->cur_transfer->cs_change)
1330 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1331 		tasklet_schedule(&pl022->pump_transfers);
1332 		return IRQ_HANDLED;
1333 	}
1334 
1335 	return IRQ_HANDLED;
1336 }
1337 
1338 /**
1339  * This sets up the pointers to memory for the next message to
1340  * send out on the SPI bus.
1341  */
1342 static int set_up_next_transfer(struct pl022 *pl022,
1343 				struct spi_transfer *transfer)
1344 {
1345 	int residue;
1346 
1347 	/* Sanity check the message for this bus width */
1348 	residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
1349 	if (unlikely(residue != 0)) {
1350 		dev_err(&pl022->adev->dev,
1351 			"message of %u bytes to transmit but the current "
1352 			"chip bus has a data width of %u bytes!\n",
1353 			pl022->cur_transfer->len,
1354 			pl022->cur_chip->n_bytes);
1355 		dev_err(&pl022->adev->dev, "skipping this message\n");
1356 		return -EIO;
1357 	}
1358 	pl022->tx = (void *)transfer->tx_buf;
1359 	pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
1360 	pl022->rx = (void *)transfer->rx_buf;
1361 	pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
1362 	pl022->write =
1363 	    pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
1364 	pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
1365 	return 0;
1366 }
1367 
1368 /**
1369  * pump_transfers - Tasklet function which schedules next transfer
1370  * when running in interrupt or DMA transfer mode.
1371  * @data: SSP driver private data structure
1372  *
1373  */
1374 static void pump_transfers(unsigned long data)
1375 {
1376 	struct pl022 *pl022 = (struct pl022 *) data;
1377 	struct spi_message *message = NULL;
1378 	struct spi_transfer *transfer = NULL;
1379 	struct spi_transfer *previous = NULL;
1380 
1381 	/* Get current state information */
1382 	message = pl022->cur_msg;
1383 	transfer = pl022->cur_transfer;
1384 
1385 	/* Handle for abort */
1386 	if (message->state == STATE_ERROR) {
1387 		message->status = -EIO;
1388 		giveback(pl022);
1389 		return;
1390 	}
1391 
1392 	/* Handle end of message */
1393 	if (message->state == STATE_DONE) {
1394 		message->status = 0;
1395 		giveback(pl022);
1396 		return;
1397 	}
1398 
1399 	/* Delay if requested at end of transfer before CS change */
1400 	if (message->state == STATE_RUNNING) {
1401 		previous = list_entry(transfer->transfer_list.prev,
1402 					struct spi_transfer,
1403 					transfer_list);
1404 		if (previous->delay_usecs)
1405 			/*
1406 			 * FIXME: This runs in interrupt context.
1407 			 * Is this really smart?
1408 			 */
1409 			udelay(previous->delay_usecs);
1410 
1411 		/* Reselect chip select only if cs_change was requested */
1412 		if (previous->cs_change)
1413 			pl022_cs_control(pl022, SSP_CHIP_SELECT);
1414 	} else {
1415 		/* STATE_START */
1416 		message->state = STATE_RUNNING;
1417 	}
1418 
1419 	if (set_up_next_transfer(pl022, transfer)) {
1420 		message->state = STATE_ERROR;
1421 		message->status = -EIO;
1422 		giveback(pl022);
1423 		return;
1424 	}
1425 	/* Flush the FIFOs and let's go! */
1426 	flush(pl022);
1427 
1428 	if (pl022->cur_chip->enable_dma) {
1429 		if (configure_dma(pl022)) {
1430 			dev_dbg(&pl022->adev->dev,
1431 				"configuration of DMA failed, fall back to interrupt mode\n");
1432 			goto err_config_dma;
1433 		}
1434 		return;
1435 	}
1436 
1437 err_config_dma:
1438 	/* enable all interrupts except RX */
1439 	writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase));
1440 }
1441 
1442 static void do_interrupt_dma_transfer(struct pl022 *pl022)
1443 {
1444 	/*
1445 	 * Default is to enable all interrupts except RX -
1446 	 * this will be enabled once TX is complete
1447 	 */
1448 	u32 irqflags = (u32)(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM);
1449 
1450 	/* Enable target chip, if not already active */
1451 	if (!pl022->next_msg_cs_active)
1452 		pl022_cs_control(pl022, SSP_CHIP_SELECT);
1453 
1454 	if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
1455 		/* Error path */
1456 		pl022->cur_msg->state = STATE_ERROR;
1457 		pl022->cur_msg->status = -EIO;
1458 		giveback(pl022);
1459 		return;
1460 	}
1461 	/* If we're using DMA, set up DMA here */
1462 	if (pl022->cur_chip->enable_dma) {
1463 		/* Configure DMA transfer */
1464 		if (configure_dma(pl022)) {
1465 			dev_dbg(&pl022->adev->dev,
1466 				"configuration of DMA failed, fall back to interrupt mode\n");
1467 			goto err_config_dma;
1468 		}
1469 		/* Disable interrupts in DMA mode, IRQ from DMA controller */
1470 		irqflags = DISABLE_ALL_INTERRUPTS;
1471 	}
1472 err_config_dma:
1473 	/* Enable SSP, turn on interrupts */
1474 	writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1475 	       SSP_CR1(pl022->virtbase));
1476 	writew(irqflags, SSP_IMSC(pl022->virtbase));
1477 }
1478 
1479 static void print_current_status(struct pl022 *pl022)
1480 {
1481 	u32 read_cr0;
1482 	u16 read_cr1, read_dmacr, read_sr;
1483 
1484 	if (pl022->vendor->extended_cr)
1485 		read_cr0 = readl(SSP_CR0(pl022->virtbase));
1486 	else
1487 		read_cr0 = readw(SSP_CR0(pl022->virtbase));
1488 	read_cr1 = readw(SSP_CR1(pl022->virtbase));
1489 	read_dmacr = readw(SSP_DMACR(pl022->virtbase));
1490 	read_sr = readw(SSP_SR(pl022->virtbase));
1491 
1492 	dev_warn(&pl022->adev->dev, "spi-pl022 CR0: %x\n", read_cr0);
1493 	dev_warn(&pl022->adev->dev, "spi-pl022 CR1: %x\n", read_cr1);
1494 	dev_warn(&pl022->adev->dev, "spi-pl022 DMACR: %x\n", read_dmacr);
1495 	dev_warn(&pl022->adev->dev, "spi-pl022 SR: %x\n", read_sr);
1496 	dev_warn(&pl022->adev->dev,
1497 			"spi-pl022 exp_fifo_level/fifodepth: %u/%d\n",
1498 			pl022->exp_fifo_level,
1499 			pl022->vendor->fifodepth);
1500 
1501 }
1502 
1503 static void do_polling_transfer(struct pl022 *pl022)
1504 {
1505 	struct spi_message *message = NULL;
1506 	struct spi_transfer *transfer = NULL;
1507 	struct spi_transfer *previous = NULL;
1508 	unsigned long time, timeout;
1509 
1510 	message = pl022->cur_msg;
1511 
1512 	while (message->state != STATE_DONE) {
1513 		/* Handle for abort */
1514 		if (message->state == STATE_ERROR)
1515 			break;
1516 		transfer = pl022->cur_transfer;
1517 
1518 		/* Delay if requested at end of transfer */
1519 		if (message->state == STATE_RUNNING) {
1520 			previous =
1521 			    list_entry(transfer->transfer_list.prev,
1522 				       struct spi_transfer, transfer_list);
1523 			if (previous->delay_usecs)
1524 				udelay(previous->delay_usecs);
1525 			if (previous->cs_change)
1526 				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1527 		} else {
1528 			/* STATE_START */
1529 			message->state = STATE_RUNNING;
1530 			if (!pl022->next_msg_cs_active)
1531 				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1532 		}
1533 
1534 		/* Configuration Changing Per Transfer */
1535 		if (set_up_next_transfer(pl022, transfer)) {
1536 			/* Error path */
1537 			message->state = STATE_ERROR;
1538 			break;
1539 		}
1540 		/* Flush FIFOs and enable SSP */
1541 		flush(pl022);
1542 		writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1543 		       SSP_CR1(pl022->virtbase));
1544 
1545 		dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
1546 
1547 		timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
1548 		while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
1549 			time = jiffies;
1550 			readwriter(pl022);
1551 			if (time_after(time, timeout)) {
1552 				dev_warn(&pl022->adev->dev,
1553 				"%s: timeout!\n", __func__);
1554 				message->state = STATE_TIMEOUT;
1555 				print_current_status(pl022);
1556 				goto out;
1557 			}
1558 			cpu_relax();
1559 		}
1560 
1561 		/* Update total byte transferred */
1562 		message->actual_length += pl022->cur_transfer->len;
1563 		/* Move to next transfer */
1564 		message->state = next_transfer(pl022);
1565 		if (message->state != STATE_DONE
1566 		    && pl022->cur_transfer->cs_change)
1567 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1568 	}
1569 out:
1570 	/* Handle end of message */
1571 	if (message->state == STATE_DONE)
1572 		message->status = 0;
1573 	else if (message->state == STATE_TIMEOUT)
1574 		message->status = -EAGAIN;
1575 	else
1576 		message->status = -EIO;
1577 
1578 	giveback(pl022);
1579 	return;
1580 }
1581 
1582 static int pl022_transfer_one_message(struct spi_master *master,
1583 				      struct spi_message *msg)
1584 {
1585 	struct pl022 *pl022 = spi_master_get_devdata(master);
1586 
1587 	/* Initial message state */
1588 	pl022->cur_msg = msg;
1589 	msg->state = STATE_START;
1590 
1591 	pl022->cur_transfer = list_entry(msg->transfers.next,
1592 					 struct spi_transfer, transfer_list);
1593 
1594 	/* Setup the SPI using the per chip configuration */
1595 	pl022->cur_chip = spi_get_ctldata(msg->spi);
1596 	pl022->cur_cs = pl022->chipselects[msg->spi->chip_select];
1597 
1598 	restore_state(pl022);
1599 	flush(pl022);
1600 
1601 	if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
1602 		do_polling_transfer(pl022);
1603 	else
1604 		do_interrupt_dma_transfer(pl022);
1605 
1606 	return 0;
1607 }
1608 
1609 static int pl022_unprepare_transfer_hardware(struct spi_master *master)
1610 {
1611 	struct pl022 *pl022 = spi_master_get_devdata(master);
1612 
1613 	/* nothing more to do - disable spi/ssp and power off */
1614 	writew((readw(SSP_CR1(pl022->virtbase)) &
1615 		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1616 
1617 	return 0;
1618 }
1619 
1620 static int verify_controller_parameters(struct pl022 *pl022,
1621 				struct pl022_config_chip const *chip_info)
1622 {
1623 	if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
1624 	    || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
1625 		dev_err(&pl022->adev->dev,
1626 			"interface is configured incorrectly\n");
1627 		return -EINVAL;
1628 	}
1629 	if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
1630 	    (!pl022->vendor->unidir)) {
1631 		dev_err(&pl022->adev->dev,
1632 			"unidirectional mode not supported in this "
1633 			"hardware version\n");
1634 		return -EINVAL;
1635 	}
1636 	if ((chip_info->hierarchy != SSP_MASTER)
1637 	    && (chip_info->hierarchy != SSP_SLAVE)) {
1638 		dev_err(&pl022->adev->dev,
1639 			"hierarchy is configured incorrectly\n");
1640 		return -EINVAL;
1641 	}
1642 	if ((chip_info->com_mode != INTERRUPT_TRANSFER)
1643 	    && (chip_info->com_mode != DMA_TRANSFER)
1644 	    && (chip_info->com_mode != POLLING_TRANSFER)) {
1645 		dev_err(&pl022->adev->dev,
1646 			"Communication mode is configured incorrectly\n");
1647 		return -EINVAL;
1648 	}
1649 	switch (chip_info->rx_lev_trig) {
1650 	case SSP_RX_1_OR_MORE_ELEM:
1651 	case SSP_RX_4_OR_MORE_ELEM:
1652 	case SSP_RX_8_OR_MORE_ELEM:
1653 		/* These are always OK, all variants can handle this */
1654 		break;
1655 	case SSP_RX_16_OR_MORE_ELEM:
1656 		if (pl022->vendor->fifodepth < 16) {
1657 			dev_err(&pl022->adev->dev,
1658 			"RX FIFO Trigger Level is configured incorrectly\n");
1659 			return -EINVAL;
1660 		}
1661 		break;
1662 	case SSP_RX_32_OR_MORE_ELEM:
1663 		if (pl022->vendor->fifodepth < 32) {
1664 			dev_err(&pl022->adev->dev,
1665 			"RX FIFO Trigger Level is configured incorrectly\n");
1666 			return -EINVAL;
1667 		}
1668 		break;
1669 	default:
1670 		dev_err(&pl022->adev->dev,
1671 			"RX FIFO Trigger Level is configured incorrectly\n");
1672 		return -EINVAL;
1673 	}
1674 	switch (chip_info->tx_lev_trig) {
1675 	case SSP_TX_1_OR_MORE_EMPTY_LOC:
1676 	case SSP_TX_4_OR_MORE_EMPTY_LOC:
1677 	case SSP_TX_8_OR_MORE_EMPTY_LOC:
1678 		/* These are always OK, all variants can handle this */
1679 		break;
1680 	case SSP_TX_16_OR_MORE_EMPTY_LOC:
1681 		if (pl022->vendor->fifodepth < 16) {
1682 			dev_err(&pl022->adev->dev,
1683 			"TX FIFO Trigger Level is configured incorrectly\n");
1684 			return -EINVAL;
1685 		}
1686 		break;
1687 	case SSP_TX_32_OR_MORE_EMPTY_LOC:
1688 		if (pl022->vendor->fifodepth < 32) {
1689 			dev_err(&pl022->adev->dev,
1690 			"TX FIFO Trigger Level is configured incorrectly\n");
1691 			return -EINVAL;
1692 		}
1693 		break;
1694 	default:
1695 		dev_err(&pl022->adev->dev,
1696 			"TX FIFO Trigger Level is configured incorrectly\n");
1697 		return -EINVAL;
1698 	}
1699 	if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
1700 		if ((chip_info->ctrl_len < SSP_BITS_4)
1701 		    || (chip_info->ctrl_len > SSP_BITS_32)) {
1702 			dev_err(&pl022->adev->dev,
1703 				"CTRL LEN is configured incorrectly\n");
1704 			return -EINVAL;
1705 		}
1706 		if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
1707 		    && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
1708 			dev_err(&pl022->adev->dev,
1709 				"Wait State is configured incorrectly\n");
1710 			return -EINVAL;
1711 		}
1712 		/* Half duplex is only available in the ST Micro version */
1713 		if (pl022->vendor->extended_cr) {
1714 			if ((chip_info->duplex !=
1715 			     SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1716 			    && (chip_info->duplex !=
1717 				SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
1718 				dev_err(&pl022->adev->dev,
1719 					"Microwire duplex mode is configured incorrectly\n");
1720 				return -EINVAL;
1721 			}
1722 		} else {
1723 			if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1724 				dev_err(&pl022->adev->dev,
1725 					"Microwire half duplex mode requested,"
1726 					" but this is only available in the"
1727 					" ST version of PL022\n");
1728 			return -EINVAL;
1729 		}
1730 	}
1731 	return 0;
1732 }
1733 
1734 static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
1735 {
1736 	return rate / (cpsdvsr * (1 + scr));
1737 }
1738 
1739 static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
1740 				    ssp_clock_params * clk_freq)
1741 {
1742 	/* Lets calculate the frequency parameters */
1743 	u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
1744 	u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
1745 		best_scr = 0, tmp, found = 0;
1746 
1747 	rate = clk_get_rate(pl022->clk);
1748 	/* cpsdvscr = 2 & scr 0 */
1749 	max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
1750 	/* cpsdvsr = 254 & scr = 255 */
1751 	min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
1752 
1753 	if (freq > max_tclk)
1754 		dev_warn(&pl022->adev->dev,
1755 			"Max speed that can be programmed is %d Hz, you requested %d\n",
1756 			max_tclk, freq);
1757 
1758 	if (freq < min_tclk) {
1759 		dev_err(&pl022->adev->dev,
1760 			"Requested frequency: %d Hz is less than minimum possible %d Hz\n",
1761 			freq, min_tclk);
1762 		return -EINVAL;
1763 	}
1764 
1765 	/*
1766 	 * best_freq will give closest possible available rate (<= requested
1767 	 * freq) for all values of scr & cpsdvsr.
1768 	 */
1769 	while ((cpsdvsr <= CPSDVR_MAX) && !found) {
1770 		while (scr <= SCR_MAX) {
1771 			tmp = spi_rate(rate, cpsdvsr, scr);
1772 
1773 			if (tmp > freq) {
1774 				/* we need lower freq */
1775 				scr++;
1776 				continue;
1777 			}
1778 
1779 			/*
1780 			 * If found exact value, mark found and break.
1781 			 * If found more closer value, update and break.
1782 			 */
1783 			if (tmp > best_freq) {
1784 				best_freq = tmp;
1785 				best_cpsdvsr = cpsdvsr;
1786 				best_scr = scr;
1787 
1788 				if (tmp == freq)
1789 					found = 1;
1790 			}
1791 			/*
1792 			 * increased scr will give lower rates, which are not
1793 			 * required
1794 			 */
1795 			break;
1796 		}
1797 		cpsdvsr += 2;
1798 		scr = SCR_MIN;
1799 	}
1800 
1801 	WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
1802 			freq);
1803 
1804 	clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
1805 	clk_freq->scr = (u8) (best_scr & 0xFF);
1806 	dev_dbg(&pl022->adev->dev,
1807 		"SSP Target Frequency is: %u, Effective Frequency is %u\n",
1808 		freq, best_freq);
1809 	dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
1810 		clk_freq->cpsdvsr, clk_freq->scr);
1811 
1812 	return 0;
1813 }
1814 
1815 /*
1816  * A piece of default chip info unless the platform
1817  * supplies it.
1818  */
1819 static const struct pl022_config_chip pl022_default_chip_info = {
1820 	.com_mode = POLLING_TRANSFER,
1821 	.iface = SSP_INTERFACE_MOTOROLA_SPI,
1822 	.hierarchy = SSP_SLAVE,
1823 	.slave_tx_disable = DO_NOT_DRIVE_TX,
1824 	.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
1825 	.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
1826 	.ctrl_len = SSP_BITS_8,
1827 	.wait_state = SSP_MWIRE_WAIT_ZERO,
1828 	.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
1829 	.cs_control = null_cs_control,
1830 };
1831 
1832 /**
1833  * pl022_setup - setup function registered to SPI master framework
1834  * @spi: spi device which is requesting setup
1835  *
1836  * This function is registered to the SPI framework for this SPI master
1837  * controller. If it is the first time when setup is called by this device,
1838  * this function will initialize the runtime state for this chip and save
1839  * the same in the device structure. Else it will update the runtime info
1840  * with the updated chip info. Nothing is really being written to the
1841  * controller hardware here, that is not done until the actual transfer
1842  * commence.
1843  */
1844 static int pl022_setup(struct spi_device *spi)
1845 {
1846 	struct pl022_config_chip const *chip_info;
1847 	struct pl022_config_chip chip_info_dt;
1848 	struct chip_data *chip;
1849 	struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
1850 	int status = 0;
1851 	struct pl022 *pl022 = spi_master_get_devdata(spi->master);
1852 	unsigned int bits = spi->bits_per_word;
1853 	u32 tmp;
1854 	struct device_node *np = spi->dev.of_node;
1855 
1856 	if (!spi->max_speed_hz)
1857 		return -EINVAL;
1858 
1859 	/* Get controller_state if one is supplied */
1860 	chip = spi_get_ctldata(spi);
1861 
1862 	if (chip == NULL) {
1863 		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1864 		if (!chip)
1865 			return -ENOMEM;
1866 		dev_dbg(&spi->dev,
1867 			"allocated memory for controller's runtime state\n");
1868 	}
1869 
1870 	/* Get controller data if one is supplied */
1871 	chip_info = spi->controller_data;
1872 
1873 	if (chip_info == NULL) {
1874 		if (np) {
1875 			chip_info_dt = pl022_default_chip_info;
1876 
1877 			chip_info_dt.hierarchy = SSP_MASTER;
1878 			of_property_read_u32(np, "pl022,interface",
1879 				&chip_info_dt.iface);
1880 			of_property_read_u32(np, "pl022,com-mode",
1881 				&chip_info_dt.com_mode);
1882 			of_property_read_u32(np, "pl022,rx-level-trig",
1883 				&chip_info_dt.rx_lev_trig);
1884 			of_property_read_u32(np, "pl022,tx-level-trig",
1885 				&chip_info_dt.tx_lev_trig);
1886 			of_property_read_u32(np, "pl022,ctrl-len",
1887 				&chip_info_dt.ctrl_len);
1888 			of_property_read_u32(np, "pl022,wait-state",
1889 				&chip_info_dt.wait_state);
1890 			of_property_read_u32(np, "pl022,duplex",
1891 				&chip_info_dt.duplex);
1892 
1893 			chip_info = &chip_info_dt;
1894 		} else {
1895 			chip_info = &pl022_default_chip_info;
1896 			/* spi_board_info.controller_data not is supplied */
1897 			dev_dbg(&spi->dev,
1898 				"using default controller_data settings\n");
1899 		}
1900 	} else
1901 		dev_dbg(&spi->dev,
1902 			"using user supplied controller_data settings\n");
1903 
1904 	/*
1905 	 * We can override with custom divisors, else we use the board
1906 	 * frequency setting
1907 	 */
1908 	if ((0 == chip_info->clk_freq.cpsdvsr)
1909 	    && (0 == chip_info->clk_freq.scr)) {
1910 		status = calculate_effective_freq(pl022,
1911 						  spi->max_speed_hz,
1912 						  &clk_freq);
1913 		if (status < 0)
1914 			goto err_config_params;
1915 	} else {
1916 		memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
1917 		if ((clk_freq.cpsdvsr % 2) != 0)
1918 			clk_freq.cpsdvsr =
1919 				clk_freq.cpsdvsr - 1;
1920 	}
1921 	if ((clk_freq.cpsdvsr < CPSDVR_MIN)
1922 	    || (clk_freq.cpsdvsr > CPSDVR_MAX)) {
1923 		status = -EINVAL;
1924 		dev_err(&spi->dev,
1925 			"cpsdvsr is configured incorrectly\n");
1926 		goto err_config_params;
1927 	}
1928 
1929 	status = verify_controller_parameters(pl022, chip_info);
1930 	if (status) {
1931 		dev_err(&spi->dev, "controller data is incorrect");
1932 		goto err_config_params;
1933 	}
1934 
1935 	pl022->rx_lev_trig = chip_info->rx_lev_trig;
1936 	pl022->tx_lev_trig = chip_info->tx_lev_trig;
1937 
1938 	/* Now set controller state based on controller data */
1939 	chip->xfer_type = chip_info->com_mode;
1940 	if (!chip_info->cs_control) {
1941 		chip->cs_control = null_cs_control;
1942 		if (!gpio_is_valid(pl022->chipselects[spi->chip_select]))
1943 			dev_warn(&spi->dev,
1944 				 "invalid chip select\n");
1945 	} else
1946 		chip->cs_control = chip_info->cs_control;
1947 
1948 	/* Check bits per word with vendor specific range */
1949 	if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
1950 		status = -ENOTSUPP;
1951 		dev_err(&spi->dev, "illegal data size for this controller!\n");
1952 		dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
1953 				pl022->vendor->max_bpw);
1954 		goto err_config_params;
1955 	} else if (bits <= 8) {
1956 		dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
1957 		chip->n_bytes = 1;
1958 		chip->read = READING_U8;
1959 		chip->write = WRITING_U8;
1960 	} else if (bits <= 16) {
1961 		dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
1962 		chip->n_bytes = 2;
1963 		chip->read = READING_U16;
1964 		chip->write = WRITING_U16;
1965 	} else {
1966 		dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
1967 		chip->n_bytes = 4;
1968 		chip->read = READING_U32;
1969 		chip->write = WRITING_U32;
1970 	}
1971 
1972 	/* Now Initialize all register settings required for this chip */
1973 	chip->cr0 = 0;
1974 	chip->cr1 = 0;
1975 	chip->dmacr = 0;
1976 	chip->cpsr = 0;
1977 	if ((chip_info->com_mode == DMA_TRANSFER)
1978 	    && ((pl022->master_info)->enable_dma)) {
1979 		chip->enable_dma = true;
1980 		dev_dbg(&spi->dev, "DMA mode set in controller state\n");
1981 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1982 			       SSP_DMACR_MASK_RXDMAE, 0);
1983 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1984 			       SSP_DMACR_MASK_TXDMAE, 1);
1985 	} else {
1986 		chip->enable_dma = false;
1987 		dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
1988 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1989 			       SSP_DMACR_MASK_RXDMAE, 0);
1990 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1991 			       SSP_DMACR_MASK_TXDMAE, 1);
1992 	}
1993 
1994 	chip->cpsr = clk_freq.cpsdvsr;
1995 
1996 	/* Special setup for the ST micro extended control registers */
1997 	if (pl022->vendor->extended_cr) {
1998 		u32 etx;
1999 
2000 		if (pl022->vendor->pl023) {
2001 			/* These bits are only in the PL023 */
2002 			SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
2003 				       SSP_CR1_MASK_FBCLKDEL_ST, 13);
2004 		} else {
2005 			/* These bits are in the PL022 but not PL023 */
2006 			SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
2007 				       SSP_CR0_MASK_HALFDUP_ST, 5);
2008 			SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
2009 				       SSP_CR0_MASK_CSS_ST, 16);
2010 			SSP_WRITE_BITS(chip->cr0, chip_info->iface,
2011 				       SSP_CR0_MASK_FRF_ST, 21);
2012 			SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
2013 				       SSP_CR1_MASK_MWAIT_ST, 6);
2014 		}
2015 		SSP_WRITE_BITS(chip->cr0, bits - 1,
2016 			       SSP_CR0_MASK_DSS_ST, 0);
2017 
2018 		if (spi->mode & SPI_LSB_FIRST) {
2019 			tmp = SSP_RX_LSB;
2020 			etx = SSP_TX_LSB;
2021 		} else {
2022 			tmp = SSP_RX_MSB;
2023 			etx = SSP_TX_MSB;
2024 		}
2025 		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
2026 		SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
2027 		SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
2028 			       SSP_CR1_MASK_RXIFLSEL_ST, 7);
2029 		SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
2030 			       SSP_CR1_MASK_TXIFLSEL_ST, 10);
2031 	} else {
2032 		SSP_WRITE_BITS(chip->cr0, bits - 1,
2033 			       SSP_CR0_MASK_DSS, 0);
2034 		SSP_WRITE_BITS(chip->cr0, chip_info->iface,
2035 			       SSP_CR0_MASK_FRF, 4);
2036 	}
2037 
2038 	/* Stuff that is common for all versions */
2039 	if (spi->mode & SPI_CPOL)
2040 		tmp = SSP_CLK_POL_IDLE_HIGH;
2041 	else
2042 		tmp = SSP_CLK_POL_IDLE_LOW;
2043 	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
2044 
2045 	if (spi->mode & SPI_CPHA)
2046 		tmp = SSP_CLK_SECOND_EDGE;
2047 	else
2048 		tmp = SSP_CLK_FIRST_EDGE;
2049 	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
2050 
2051 	SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
2052 	/* Loopback is available on all versions except PL023 */
2053 	if (pl022->vendor->loopback) {
2054 		if (spi->mode & SPI_LOOP)
2055 			tmp = LOOPBACK_ENABLED;
2056 		else
2057 			tmp = LOOPBACK_DISABLED;
2058 		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
2059 	}
2060 	SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
2061 	SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
2062 	SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
2063 		3);
2064 
2065 	/* Save controller_state */
2066 	spi_set_ctldata(spi, chip);
2067 	return status;
2068  err_config_params:
2069 	spi_set_ctldata(spi, NULL);
2070 	kfree(chip);
2071 	return status;
2072 }
2073 
2074 /**
2075  * pl022_cleanup - cleanup function registered to SPI master framework
2076  * @spi: spi device which is requesting cleanup
2077  *
2078  * This function is registered to the SPI framework for this SPI master
2079  * controller. It will free the runtime state of chip.
2080  */
2081 static void pl022_cleanup(struct spi_device *spi)
2082 {
2083 	struct chip_data *chip = spi_get_ctldata(spi);
2084 
2085 	spi_set_ctldata(spi, NULL);
2086 	kfree(chip);
2087 }
2088 
2089 static struct pl022_ssp_controller *
2090 pl022_platform_data_dt_get(struct device *dev)
2091 {
2092 	struct device_node *np = dev->of_node;
2093 	struct pl022_ssp_controller *pd;
2094 	u32 tmp = 0;
2095 
2096 	if (!np) {
2097 		dev_err(dev, "no dt node defined\n");
2098 		return NULL;
2099 	}
2100 
2101 	pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
2102 	if (!pd)
2103 		return NULL;
2104 
2105 	pd->bus_id = -1;
2106 	pd->enable_dma = 1;
2107 	of_property_read_u32(np, "num-cs", &tmp);
2108 	pd->num_chipselect = tmp;
2109 	of_property_read_u32(np, "pl022,autosuspend-delay",
2110 			     &pd->autosuspend_delay);
2111 	pd->rt = of_property_read_bool(np, "pl022,rt");
2112 
2113 	return pd;
2114 }
2115 
2116 static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
2117 {
2118 	struct device *dev = &adev->dev;
2119 	struct pl022_ssp_controller *platform_info =
2120 			dev_get_platdata(&adev->dev);
2121 	struct spi_master *master;
2122 	struct pl022 *pl022 = NULL;	/*Data for this driver */
2123 	struct device_node *np = adev->dev.of_node;
2124 	int status = 0, i, num_cs;
2125 
2126 	dev_info(&adev->dev,
2127 		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
2128 	if (!platform_info && IS_ENABLED(CONFIG_OF))
2129 		platform_info = pl022_platform_data_dt_get(dev);
2130 
2131 	if (!platform_info) {
2132 		dev_err(dev, "probe: no platform data defined\n");
2133 		return -ENODEV;
2134 	}
2135 
2136 	if (platform_info->num_chipselect) {
2137 		num_cs = platform_info->num_chipselect;
2138 	} else {
2139 		dev_err(dev, "probe: no chip select defined\n");
2140 		return -ENODEV;
2141 	}
2142 
2143 	/* Allocate master with space for data */
2144 	master = spi_alloc_master(dev, sizeof(struct pl022));
2145 	if (master == NULL) {
2146 		dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
2147 		return -ENOMEM;
2148 	}
2149 
2150 	pl022 = spi_master_get_devdata(master);
2151 	pl022->master = master;
2152 	pl022->master_info = platform_info;
2153 	pl022->adev = adev;
2154 	pl022->vendor = id->data;
2155 	pl022->chipselects = devm_kcalloc(dev, num_cs, sizeof(int),
2156 					  GFP_KERNEL);
2157 	if (!pl022->chipselects) {
2158 		status = -ENOMEM;
2159 		goto err_no_mem;
2160 	}
2161 
2162 	/*
2163 	 * Bus Number Which has been Assigned to this SSP controller
2164 	 * on this board
2165 	 */
2166 	master->bus_num = platform_info->bus_id;
2167 	master->num_chipselect = num_cs;
2168 	master->cleanup = pl022_cleanup;
2169 	master->setup = pl022_setup;
2170 	master->auto_runtime_pm = true;
2171 	master->transfer_one_message = pl022_transfer_one_message;
2172 	master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
2173 	master->rt = platform_info->rt;
2174 	master->dev.of_node = dev->of_node;
2175 
2176 	if (platform_info->num_chipselect && platform_info->chipselects) {
2177 		for (i = 0; i < num_cs; i++)
2178 			pl022->chipselects[i] = platform_info->chipselects[i];
2179 	} else if (pl022->vendor->internal_cs_ctrl) {
2180 		for (i = 0; i < num_cs; i++)
2181 			pl022->chipselects[i] = i;
2182 	} else if (IS_ENABLED(CONFIG_OF)) {
2183 		for (i = 0; i < num_cs; i++) {
2184 			int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
2185 
2186 			if (cs_gpio == -EPROBE_DEFER) {
2187 				status = -EPROBE_DEFER;
2188 				goto err_no_gpio;
2189 			}
2190 
2191 			pl022->chipselects[i] = cs_gpio;
2192 
2193 			if (gpio_is_valid(cs_gpio)) {
2194 				if (devm_gpio_request(dev, cs_gpio, "ssp-pl022"))
2195 					dev_err(&adev->dev,
2196 						"could not request %d gpio\n",
2197 						cs_gpio);
2198 				else if (gpio_direction_output(cs_gpio, 1))
2199 					dev_err(&adev->dev,
2200 						"could not set gpio %d as output\n",
2201 						cs_gpio);
2202 			}
2203 		}
2204 	}
2205 
2206 	/*
2207 	 * Supports mode 0-3, loopback, and active low CS. Transfers are
2208 	 * always MS bit first on the original pl022.
2209 	 */
2210 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
2211 	if (pl022->vendor->extended_cr)
2212 		master->mode_bits |= SPI_LSB_FIRST;
2213 
2214 	dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
2215 
2216 	status = amba_request_regions(adev, NULL);
2217 	if (status)
2218 		goto err_no_ioregion;
2219 
2220 	pl022->phybase = adev->res.start;
2221 	pl022->virtbase = devm_ioremap(dev, adev->res.start,
2222 				       resource_size(&adev->res));
2223 	if (pl022->virtbase == NULL) {
2224 		status = -ENOMEM;
2225 		goto err_no_ioremap;
2226 	}
2227 	dev_info(&adev->dev, "mapped registers from %pa to %p\n",
2228 		&adev->res.start, pl022->virtbase);
2229 
2230 	pl022->clk = devm_clk_get(&adev->dev, NULL);
2231 	if (IS_ERR(pl022->clk)) {
2232 		status = PTR_ERR(pl022->clk);
2233 		dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
2234 		goto err_no_clk;
2235 	}
2236 
2237 	status = clk_prepare_enable(pl022->clk);
2238 	if (status) {
2239 		dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
2240 		goto err_no_clk_en;
2241 	}
2242 
2243 	/* Initialize transfer pump */
2244 	tasklet_init(&pl022->pump_transfers, pump_transfers,
2245 		     (unsigned long)pl022);
2246 
2247 	/* Disable SSP */
2248 	writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
2249 	       SSP_CR1(pl022->virtbase));
2250 	load_ssp_default_config(pl022);
2251 
2252 	status = devm_request_irq(dev, adev->irq[0], pl022_interrupt_handler,
2253 				  0, "pl022", pl022);
2254 	if (status < 0) {
2255 		dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
2256 		goto err_no_irq;
2257 	}
2258 
2259 	/* Get DMA channels, try autoconfiguration first */
2260 	status = pl022_dma_autoprobe(pl022);
2261 	if (status == -EPROBE_DEFER) {
2262 		dev_dbg(dev, "deferring probe to get DMA channel\n");
2263 		goto err_no_irq;
2264 	}
2265 
2266 	/* If that failed, use channels from platform_info */
2267 	if (status == 0)
2268 		platform_info->enable_dma = 1;
2269 	else if (platform_info->enable_dma) {
2270 		status = pl022_dma_probe(pl022);
2271 		if (status != 0)
2272 			platform_info->enable_dma = 0;
2273 	}
2274 
2275 	/* Register with the SPI framework */
2276 	amba_set_drvdata(adev, pl022);
2277 	status = devm_spi_register_master(&adev->dev, master);
2278 	if (status != 0) {
2279 		dev_err(&adev->dev,
2280 			"probe - problem registering spi master\n");
2281 		goto err_spi_register;
2282 	}
2283 	dev_dbg(dev, "probe succeeded\n");
2284 
2285 	/* let runtime pm put suspend */
2286 	if (platform_info->autosuspend_delay > 0) {
2287 		dev_info(&adev->dev,
2288 			"will use autosuspend for runtime pm, delay %dms\n",
2289 			platform_info->autosuspend_delay);
2290 		pm_runtime_set_autosuspend_delay(dev,
2291 			platform_info->autosuspend_delay);
2292 		pm_runtime_use_autosuspend(dev);
2293 	}
2294 	pm_runtime_put(dev);
2295 
2296 	return 0;
2297 
2298  err_spi_register:
2299 	if (platform_info->enable_dma)
2300 		pl022_dma_remove(pl022);
2301  err_no_irq:
2302 	clk_disable_unprepare(pl022->clk);
2303  err_no_clk_en:
2304  err_no_clk:
2305  err_no_ioremap:
2306 	amba_release_regions(adev);
2307  err_no_ioregion:
2308  err_no_gpio:
2309  err_no_mem:
2310 	spi_master_put(master);
2311 	return status;
2312 }
2313 
2314 static int
2315 pl022_remove(struct amba_device *adev)
2316 {
2317 	struct pl022 *pl022 = amba_get_drvdata(adev);
2318 
2319 	if (!pl022)
2320 		return 0;
2321 
2322 	/*
2323 	 * undo pm_runtime_put() in probe.  I assume that we're not
2324 	 * accessing the primecell here.
2325 	 */
2326 	pm_runtime_get_noresume(&adev->dev);
2327 
2328 	load_ssp_default_config(pl022);
2329 	if (pl022->master_info->enable_dma)
2330 		pl022_dma_remove(pl022);
2331 
2332 	clk_disable_unprepare(pl022->clk);
2333 	amba_release_regions(adev);
2334 	tasklet_disable(&pl022->pump_transfers);
2335 	return 0;
2336 }
2337 
2338 #ifdef CONFIG_PM_SLEEP
2339 static int pl022_suspend(struct device *dev)
2340 {
2341 	struct pl022 *pl022 = dev_get_drvdata(dev);
2342 	int ret;
2343 
2344 	ret = spi_master_suspend(pl022->master);
2345 	if (ret)
2346 		return ret;
2347 
2348 	ret = pm_runtime_force_suspend(dev);
2349 	if (ret) {
2350 		spi_master_resume(pl022->master);
2351 		return ret;
2352 	}
2353 
2354 	pinctrl_pm_select_sleep_state(dev);
2355 
2356 	dev_dbg(dev, "suspended\n");
2357 	return 0;
2358 }
2359 
2360 static int pl022_resume(struct device *dev)
2361 {
2362 	struct pl022 *pl022 = dev_get_drvdata(dev);
2363 	int ret;
2364 
2365 	ret = pm_runtime_force_resume(dev);
2366 	if (ret)
2367 		dev_err(dev, "problem resuming\n");
2368 
2369 	/* Start the queue running */
2370 	ret = spi_master_resume(pl022->master);
2371 	if (!ret)
2372 		dev_dbg(dev, "resumed\n");
2373 
2374 	return ret;
2375 }
2376 #endif
2377 
2378 #ifdef CONFIG_PM
2379 static int pl022_runtime_suspend(struct device *dev)
2380 {
2381 	struct pl022 *pl022 = dev_get_drvdata(dev);
2382 
2383 	clk_disable_unprepare(pl022->clk);
2384 	pinctrl_pm_select_idle_state(dev);
2385 
2386 	return 0;
2387 }
2388 
2389 static int pl022_runtime_resume(struct device *dev)
2390 {
2391 	struct pl022 *pl022 = dev_get_drvdata(dev);
2392 
2393 	pinctrl_pm_select_default_state(dev);
2394 	clk_prepare_enable(pl022->clk);
2395 
2396 	return 0;
2397 }
2398 #endif
2399 
2400 static const struct dev_pm_ops pl022_dev_pm_ops = {
2401 	SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
2402 	SET_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
2403 };
2404 
2405 static struct vendor_data vendor_arm = {
2406 	.fifodepth = 8,
2407 	.max_bpw = 16,
2408 	.unidir = false,
2409 	.extended_cr = false,
2410 	.pl023 = false,
2411 	.loopback = true,
2412 	.internal_cs_ctrl = false,
2413 };
2414 
2415 static struct vendor_data vendor_st = {
2416 	.fifodepth = 32,
2417 	.max_bpw = 32,
2418 	.unidir = false,
2419 	.extended_cr = true,
2420 	.pl023 = false,
2421 	.loopback = true,
2422 	.internal_cs_ctrl = false,
2423 };
2424 
2425 static struct vendor_data vendor_st_pl023 = {
2426 	.fifodepth = 32,
2427 	.max_bpw = 32,
2428 	.unidir = false,
2429 	.extended_cr = true,
2430 	.pl023 = true,
2431 	.loopback = false,
2432 	.internal_cs_ctrl = false,
2433 };
2434 
2435 static struct vendor_data vendor_lsi = {
2436 	.fifodepth = 8,
2437 	.max_bpw = 16,
2438 	.unidir = false,
2439 	.extended_cr = false,
2440 	.pl023 = false,
2441 	.loopback = true,
2442 	.internal_cs_ctrl = true,
2443 };
2444 
2445 static const struct amba_id pl022_ids[] = {
2446 	{
2447 		/*
2448 		 * ARM PL022 variant, this has a 16bit wide
2449 		 * and 8 locations deep TX/RX FIFO
2450 		 */
2451 		.id	= 0x00041022,
2452 		.mask	= 0x000fffff,
2453 		.data	= &vendor_arm,
2454 	},
2455 	{
2456 		/*
2457 		 * ST Micro derivative, this has 32bit wide
2458 		 * and 32 locations deep TX/RX FIFO
2459 		 */
2460 		.id	= 0x01080022,
2461 		.mask	= 0xffffffff,
2462 		.data	= &vendor_st,
2463 	},
2464 	{
2465 		/*
2466 		 * ST-Ericsson derivative "PL023" (this is not
2467 		 * an official ARM number), this is a PL022 SSP block
2468 		 * stripped to SPI mode only, it has 32bit wide
2469 		 * and 32 locations deep TX/RX FIFO but no extended
2470 		 * CR0/CR1 register
2471 		 */
2472 		.id	= 0x00080023,
2473 		.mask	= 0xffffffff,
2474 		.data	= &vendor_st_pl023,
2475 	},
2476 	{
2477 		/*
2478 		 * PL022 variant that has a chip select control register whih
2479 		 * allows control of 5 output signals nCS[0:4].
2480 		 */
2481 		.id	= 0x000b6022,
2482 		.mask	= 0x000fffff,
2483 		.data	= &vendor_lsi,
2484 	},
2485 	{ 0, 0 },
2486 };
2487 
2488 MODULE_DEVICE_TABLE(amba, pl022_ids);
2489 
2490 static struct amba_driver pl022_driver = {
2491 	.drv = {
2492 		.name	= "ssp-pl022",
2493 		.pm	= &pl022_dev_pm_ops,
2494 	},
2495 	.id_table	= pl022_ids,
2496 	.probe		= pl022_probe,
2497 	.remove		= pl022_remove,
2498 };
2499 
2500 static int __init pl022_init(void)
2501 {
2502 	return amba_driver_register(&pl022_driver);
2503 }
2504 subsys_initcall(pl022_init);
2505 
2506 static void __exit pl022_exit(void)
2507 {
2508 	amba_driver_unregister(&pl022_driver);
2509 }
2510 module_exit(pl022_exit);
2511 
2512 MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
2513 MODULE_DESCRIPTION("PL022 SSP Controller Driver");
2514 MODULE_LICENSE("GPL");
2515