xref: /linux/drivers/spi/spi-pl022.c (revision c4c11dd160a8cc98f402c4e12f94b1572e822ffd)
1 /*
2  * A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
3  *
4  * Copyright (C) 2008-2012 ST-Ericsson AB
5  * Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
6  *
7  * Author: Linus Walleij <linus.walleij@stericsson.com>
8  *
9  * Initial version inspired by:
10  *	linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
11  * Initial adoption to PL022 by:
12  *      Sachin Verma <sachin.verma@st.com>
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2 of the License, or
17  * (at your option) any later version.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  */
24 
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/device.h>
28 #include <linux/ioport.h>
29 #include <linux/errno.h>
30 #include <linux/interrupt.h>
31 #include <linux/spi/spi.h>
32 #include <linux/delay.h>
33 #include <linux/clk.h>
34 #include <linux/err.h>
35 #include <linux/amba/bus.h>
36 #include <linux/amba/pl022.h>
37 #include <linux/io.h>
38 #include <linux/slab.h>
39 #include <linux/dmaengine.h>
40 #include <linux/dma-mapping.h>
41 #include <linux/scatterlist.h>
42 #include <linux/pm_runtime.h>
43 #include <linux/gpio.h>
44 #include <linux/of_gpio.h>
45 #include <linux/pinctrl/consumer.h>
46 
47 /*
48  * This macro is used to define some register default values.
49  * reg is masked with mask, the OR:ed with an (again masked)
50  * val shifted sb steps to the left.
51  */
52 #define SSP_WRITE_BITS(reg, val, mask, sb) \
53  ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))
54 
55 /*
56  * This macro is also used to define some default values.
57  * It will just shift val by sb steps to the left and mask
58  * the result with mask.
59  */
60 #define GEN_MASK_BITS(val, mask, sb) \
61  (((val)<<(sb)) & (mask))
62 
63 #define DRIVE_TX		0
64 #define DO_NOT_DRIVE_TX		1
65 
66 #define DO_NOT_QUEUE_DMA	0
67 #define QUEUE_DMA		1
68 
69 #define RX_TRANSFER		1
70 #define TX_TRANSFER		2
71 
72 /*
73  * Macros to access SSP Registers with their offsets
74  */
75 #define SSP_CR0(r)	(r + 0x000)
76 #define SSP_CR1(r)	(r + 0x004)
77 #define SSP_DR(r)	(r + 0x008)
78 #define SSP_SR(r)	(r + 0x00C)
79 #define SSP_CPSR(r)	(r + 0x010)
80 #define SSP_IMSC(r)	(r + 0x014)
81 #define SSP_RIS(r)	(r + 0x018)
82 #define SSP_MIS(r)	(r + 0x01C)
83 #define SSP_ICR(r)	(r + 0x020)
84 #define SSP_DMACR(r)	(r + 0x024)
85 #define SSP_ITCR(r)	(r + 0x080)
86 #define SSP_ITIP(r)	(r + 0x084)
87 #define SSP_ITOP(r)	(r + 0x088)
88 #define SSP_TDR(r)	(r + 0x08C)
89 
90 #define SSP_PID0(r)	(r + 0xFE0)
91 #define SSP_PID1(r)	(r + 0xFE4)
92 #define SSP_PID2(r)	(r + 0xFE8)
93 #define SSP_PID3(r)	(r + 0xFEC)
94 
95 #define SSP_CID0(r)	(r + 0xFF0)
96 #define SSP_CID1(r)	(r + 0xFF4)
97 #define SSP_CID2(r)	(r + 0xFF8)
98 #define SSP_CID3(r)	(r + 0xFFC)
99 
100 /*
101  * SSP Control Register 0  - SSP_CR0
102  */
103 #define SSP_CR0_MASK_DSS	(0x0FUL << 0)
104 #define SSP_CR0_MASK_FRF	(0x3UL << 4)
105 #define SSP_CR0_MASK_SPO	(0x1UL << 6)
106 #define SSP_CR0_MASK_SPH	(0x1UL << 7)
107 #define SSP_CR0_MASK_SCR	(0xFFUL << 8)
108 
109 /*
110  * The ST version of this block moves som bits
111  * in SSP_CR0 and extends it to 32 bits
112  */
113 #define SSP_CR0_MASK_DSS_ST	(0x1FUL << 0)
114 #define SSP_CR0_MASK_HALFDUP_ST	(0x1UL << 5)
115 #define SSP_CR0_MASK_CSS_ST	(0x1FUL << 16)
116 #define SSP_CR0_MASK_FRF_ST	(0x3UL << 21)
117 
118 /*
119  * SSP Control Register 0  - SSP_CR1
120  */
121 #define SSP_CR1_MASK_LBM	(0x1UL << 0)
122 #define SSP_CR1_MASK_SSE	(0x1UL << 1)
123 #define SSP_CR1_MASK_MS		(0x1UL << 2)
124 #define SSP_CR1_MASK_SOD	(0x1UL << 3)
125 
126 /*
127  * The ST version of this block adds some bits
128  * in SSP_CR1
129  */
130 #define SSP_CR1_MASK_RENDN_ST	(0x1UL << 4)
131 #define SSP_CR1_MASK_TENDN_ST	(0x1UL << 5)
132 #define SSP_CR1_MASK_MWAIT_ST	(0x1UL << 6)
133 #define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
134 #define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
135 /* This one is only in the PL023 variant */
136 #define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)
137 
138 /*
139  * SSP Status Register - SSP_SR
140  */
141 #define SSP_SR_MASK_TFE		(0x1UL << 0) /* Transmit FIFO empty */
142 #define SSP_SR_MASK_TNF		(0x1UL << 1) /* Transmit FIFO not full */
143 #define SSP_SR_MASK_RNE		(0x1UL << 2) /* Receive FIFO not empty */
144 #define SSP_SR_MASK_RFF		(0x1UL << 3) /* Receive FIFO full */
145 #define SSP_SR_MASK_BSY		(0x1UL << 4) /* Busy Flag */
146 
147 /*
148  * SSP Clock Prescale Register  - SSP_CPSR
149  */
150 #define SSP_CPSR_MASK_CPSDVSR	(0xFFUL << 0)
151 
152 /*
153  * SSP Interrupt Mask Set/Clear Register - SSP_IMSC
154  */
155 #define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
156 #define SSP_IMSC_MASK_RTIM  (0x1UL << 1) /* Receive timeout Interrupt mask */
157 #define SSP_IMSC_MASK_RXIM  (0x1UL << 2) /* Receive FIFO Interrupt mask */
158 #define SSP_IMSC_MASK_TXIM  (0x1UL << 3) /* Transmit FIFO Interrupt mask */
159 
160 /*
161  * SSP Raw Interrupt Status Register - SSP_RIS
162  */
163 /* Receive Overrun Raw Interrupt status */
164 #define SSP_RIS_MASK_RORRIS		(0x1UL << 0)
165 /* Receive Timeout Raw Interrupt status */
166 #define SSP_RIS_MASK_RTRIS		(0x1UL << 1)
167 /* Receive FIFO Raw Interrupt status */
168 #define SSP_RIS_MASK_RXRIS		(0x1UL << 2)
169 /* Transmit FIFO Raw Interrupt status */
170 #define SSP_RIS_MASK_TXRIS		(0x1UL << 3)
171 
172 /*
173  * SSP Masked Interrupt Status Register - SSP_MIS
174  */
175 /* Receive Overrun Masked Interrupt status */
176 #define SSP_MIS_MASK_RORMIS		(0x1UL << 0)
177 /* Receive Timeout Masked Interrupt status */
178 #define SSP_MIS_MASK_RTMIS		(0x1UL << 1)
179 /* Receive FIFO Masked Interrupt status */
180 #define SSP_MIS_MASK_RXMIS		(0x1UL << 2)
181 /* Transmit FIFO Masked Interrupt status */
182 #define SSP_MIS_MASK_TXMIS		(0x1UL << 3)
183 
184 /*
185  * SSP Interrupt Clear Register - SSP_ICR
186  */
187 /* Receive Overrun Raw Clear Interrupt bit */
188 #define SSP_ICR_MASK_RORIC		(0x1UL << 0)
189 /* Receive Timeout Clear Interrupt bit */
190 #define SSP_ICR_MASK_RTIC		(0x1UL << 1)
191 
192 /*
193  * SSP DMA Control Register - SSP_DMACR
194  */
195 /* Receive DMA Enable bit */
196 #define SSP_DMACR_MASK_RXDMAE		(0x1UL << 0)
197 /* Transmit DMA Enable bit */
198 #define SSP_DMACR_MASK_TXDMAE		(0x1UL << 1)
199 
200 /*
201  * SSP Integration Test control Register - SSP_ITCR
202  */
203 #define SSP_ITCR_MASK_ITEN		(0x1UL << 0)
204 #define SSP_ITCR_MASK_TESTFIFO		(0x1UL << 1)
205 
206 /*
207  * SSP Integration Test Input Register - SSP_ITIP
208  */
209 #define ITIP_MASK_SSPRXD		 (0x1UL << 0)
210 #define ITIP_MASK_SSPFSSIN		 (0x1UL << 1)
211 #define ITIP_MASK_SSPCLKIN		 (0x1UL << 2)
212 #define ITIP_MASK_RXDMAC		 (0x1UL << 3)
213 #define ITIP_MASK_TXDMAC		 (0x1UL << 4)
214 #define ITIP_MASK_SSPTXDIN		 (0x1UL << 5)
215 
216 /*
217  * SSP Integration Test output Register - SSP_ITOP
218  */
219 #define ITOP_MASK_SSPTXD		 (0x1UL << 0)
220 #define ITOP_MASK_SSPFSSOUT		 (0x1UL << 1)
221 #define ITOP_MASK_SSPCLKOUT		 (0x1UL << 2)
222 #define ITOP_MASK_SSPOEn		 (0x1UL << 3)
223 #define ITOP_MASK_SSPCTLOEn		 (0x1UL << 4)
224 #define ITOP_MASK_RORINTR		 (0x1UL << 5)
225 #define ITOP_MASK_RTINTR		 (0x1UL << 6)
226 #define ITOP_MASK_RXINTR		 (0x1UL << 7)
227 #define ITOP_MASK_TXINTR		 (0x1UL << 8)
228 #define ITOP_MASK_INTR			 (0x1UL << 9)
229 #define ITOP_MASK_RXDMABREQ		 (0x1UL << 10)
230 #define ITOP_MASK_RXDMASREQ		 (0x1UL << 11)
231 #define ITOP_MASK_TXDMABREQ		 (0x1UL << 12)
232 #define ITOP_MASK_TXDMASREQ		 (0x1UL << 13)
233 
234 /*
235  * SSP Test Data Register - SSP_TDR
236  */
237 #define TDR_MASK_TESTDATA		(0xFFFFFFFF)
238 
239 /*
240  * Message State
241  * we use the spi_message.state (void *) pointer to
242  * hold a single state value, that's why all this
243  * (void *) casting is done here.
244  */
245 #define STATE_START			((void *) 0)
246 #define STATE_RUNNING			((void *) 1)
247 #define STATE_DONE			((void *) 2)
248 #define STATE_ERROR			((void *) -1)
249 
250 /*
251  * SSP State - Whether Enabled or Disabled
252  */
253 #define SSP_DISABLED			(0)
254 #define SSP_ENABLED			(1)
255 
256 /*
257  * SSP DMA State - Whether DMA Enabled or Disabled
258  */
259 #define SSP_DMA_DISABLED		(0)
260 #define SSP_DMA_ENABLED			(1)
261 
262 /*
263  * SSP Clock Defaults
264  */
265 #define SSP_DEFAULT_CLKRATE 0x2
266 #define SSP_DEFAULT_PRESCALE 0x40
267 
268 /*
269  * SSP Clock Parameter ranges
270  */
271 #define CPSDVR_MIN 0x02
272 #define CPSDVR_MAX 0xFE
273 #define SCR_MIN 0x00
274 #define SCR_MAX 0xFF
275 
276 /*
277  * SSP Interrupt related Macros
278  */
279 #define DEFAULT_SSP_REG_IMSC  0x0UL
280 #define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
281 #define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC)
282 
283 #define CLEAR_ALL_INTERRUPTS  0x3
284 
285 #define SPI_POLLING_TIMEOUT 1000
286 
287 /*
288  * The type of reading going on on this chip
289  */
290 enum ssp_reading {
291 	READING_NULL,
292 	READING_U8,
293 	READING_U16,
294 	READING_U32
295 };
296 
297 /**
298  * The type of writing going on on this chip
299  */
300 enum ssp_writing {
301 	WRITING_NULL,
302 	WRITING_U8,
303 	WRITING_U16,
304 	WRITING_U32
305 };
306 
307 /**
308  * struct vendor_data - vendor-specific config parameters
309  * for PL022 derivates
310  * @fifodepth: depth of FIFOs (both)
311  * @max_bpw: maximum number of bits per word
312  * @unidir: supports unidirection transfers
313  * @extended_cr: 32 bit wide control register 0 with extra
314  * features and extra features in CR1 as found in the ST variants
315  * @pl023: supports a subset of the ST extensions called "PL023"
316  */
317 struct vendor_data {
318 	int fifodepth;
319 	int max_bpw;
320 	bool unidir;
321 	bool extended_cr;
322 	bool pl023;
323 	bool loopback;
324 };
325 
326 /**
327  * struct pl022 - This is the private SSP driver data structure
328  * @adev: AMBA device model hookup
329  * @vendor: vendor data for the IP block
330  * @phybase: the physical memory where the SSP device resides
331  * @virtbase: the virtual memory where the SSP is mapped
332  * @clk: outgoing clock "SPICLK" for the SPI bus
333  * @master: SPI framework hookup
334  * @master_info: controller-specific data from machine setup
335  * @kworker: thread struct for message pump
336  * @kworker_task: pointer to task for message pump kworker thread
337  * @pump_messages: work struct for scheduling work to the message pump
338  * @queue_lock: spinlock to syncronise access to message queue
339  * @queue: message queue
340  * @busy: message pump is busy
341  * @running: message pump is running
342  * @pump_transfers: Tasklet used in Interrupt Transfer mode
343  * @cur_msg: Pointer to current spi_message being processed
344  * @cur_transfer: Pointer to current spi_transfer
345  * @cur_chip: pointer to current clients chip(assigned from controller_state)
346  * @next_msg_cs_active: the next message in the queue has been examined
347  *  and it was found that it uses the same chip select as the previous
348  *  message, so we left it active after the previous transfer, and it's
349  *  active already.
350  * @tx: current position in TX buffer to be read
351  * @tx_end: end position in TX buffer to be read
352  * @rx: current position in RX buffer to be written
353  * @rx_end: end position in RX buffer to be written
354  * @read: the type of read currently going on
355  * @write: the type of write currently going on
356  * @exp_fifo_level: expected FIFO level
357  * @dma_rx_channel: optional channel for RX DMA
358  * @dma_tx_channel: optional channel for TX DMA
359  * @sgt_rx: scattertable for the RX transfer
360  * @sgt_tx: scattertable for the TX transfer
361  * @dummypage: a dummy page used for driving data on the bus with DMA
362  * @cur_cs: current chip select (gpio)
363  * @chipselects: list of chipselects (gpios)
364  */
365 struct pl022 {
366 	struct amba_device		*adev;
367 	struct vendor_data		*vendor;
368 	resource_size_t			phybase;
369 	void __iomem			*virtbase;
370 	struct clk			*clk;
371 	struct spi_master		*master;
372 	struct pl022_ssp_controller	*master_info;
373 	/* Message per-transfer pump */
374 	struct tasklet_struct		pump_transfers;
375 	struct spi_message		*cur_msg;
376 	struct spi_transfer		*cur_transfer;
377 	struct chip_data		*cur_chip;
378 	bool				next_msg_cs_active;
379 	void				*tx;
380 	void				*tx_end;
381 	void				*rx;
382 	void				*rx_end;
383 	enum ssp_reading		read;
384 	enum ssp_writing		write;
385 	u32				exp_fifo_level;
386 	enum ssp_rx_level_trig		rx_lev_trig;
387 	enum ssp_tx_level_trig		tx_lev_trig;
388 	/* DMA settings */
389 #ifdef CONFIG_DMA_ENGINE
390 	struct dma_chan			*dma_rx_channel;
391 	struct dma_chan			*dma_tx_channel;
392 	struct sg_table			sgt_rx;
393 	struct sg_table			sgt_tx;
394 	char				*dummypage;
395 	bool				dma_running;
396 #endif
397 	int cur_cs;
398 	int *chipselects;
399 };
400 
401 /**
402  * struct chip_data - To maintain runtime state of SSP for each client chip
403  * @cr0: Value of control register CR0 of SSP - on later ST variants this
404  *       register is 32 bits wide rather than just 16
405  * @cr1: Value of control register CR1 of SSP
406  * @dmacr: Value of DMA control Register of SSP
407  * @cpsr: Value of Clock prescale register
408  * @n_bytes: how many bytes(power of 2) reqd for a given data width of client
409  * @enable_dma: Whether to enable DMA or not
410  * @read: function ptr to be used to read when doing xfer for this chip
411  * @write: function ptr to be used to write when doing xfer for this chip
412  * @cs_control: chip select callback provided by chip
413  * @xfer_type: polling/interrupt/DMA
414  *
415  * Runtime state of the SSP controller, maintained per chip,
416  * This would be set according to the current message that would be served
417  */
418 struct chip_data {
419 	u32 cr0;
420 	u16 cr1;
421 	u16 dmacr;
422 	u16 cpsr;
423 	u8 n_bytes;
424 	bool enable_dma;
425 	enum ssp_reading read;
426 	enum ssp_writing write;
427 	void (*cs_control) (u32 command);
428 	int xfer_type;
429 };
430 
431 /**
432  * null_cs_control - Dummy chip select function
433  * @command: select/delect the chip
434  *
435  * If no chip select function is provided by client this is used as dummy
436  * chip select
437  */
438 static void null_cs_control(u32 command)
439 {
440 	pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
441 }
442 
443 static void pl022_cs_control(struct pl022 *pl022, u32 command)
444 {
445 	if (gpio_is_valid(pl022->cur_cs))
446 		gpio_set_value(pl022->cur_cs, command);
447 	else
448 		pl022->cur_chip->cs_control(command);
449 }
450 
451 /**
452  * giveback - current spi_message is over, schedule next message and call
453  * callback of this message. Assumes that caller already
454  * set message->status; dma and pio irqs are blocked
455  * @pl022: SSP driver private data structure
456  */
457 static void giveback(struct pl022 *pl022)
458 {
459 	struct spi_transfer *last_transfer;
460 	pl022->next_msg_cs_active = false;
461 
462 	last_transfer = list_entry(pl022->cur_msg->transfers.prev,
463 					struct spi_transfer,
464 					transfer_list);
465 
466 	/* Delay if requested before any change in chip select */
467 	if (last_transfer->delay_usecs)
468 		/*
469 		 * FIXME: This runs in interrupt context.
470 		 * Is this really smart?
471 		 */
472 		udelay(last_transfer->delay_usecs);
473 
474 	if (!last_transfer->cs_change) {
475 		struct spi_message *next_msg;
476 
477 		/*
478 		 * cs_change was not set. We can keep the chip select
479 		 * enabled if there is message in the queue and it is
480 		 * for the same spi device.
481 		 *
482 		 * We cannot postpone this until pump_messages, because
483 		 * after calling msg->complete (below) the driver that
484 		 * sent the current message could be unloaded, which
485 		 * could invalidate the cs_control() callback...
486 		 */
487 		/* get a pointer to the next message, if any */
488 		next_msg = spi_get_next_queued_message(pl022->master);
489 
490 		/*
491 		 * see if the next and current messages point
492 		 * to the same spi device.
493 		 */
494 		if (next_msg && next_msg->spi != pl022->cur_msg->spi)
495 			next_msg = NULL;
496 		if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
497 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
498 		else
499 			pl022->next_msg_cs_active = true;
500 
501 	}
502 
503 	pl022->cur_msg = NULL;
504 	pl022->cur_transfer = NULL;
505 	pl022->cur_chip = NULL;
506 	spi_finalize_current_message(pl022->master);
507 
508 	/* disable the SPI/SSP operation */
509 	writew((readw(SSP_CR1(pl022->virtbase)) &
510 		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
511 
512 }
513 
514 /**
515  * flush - flush the FIFO to reach a clean state
516  * @pl022: SSP driver private data structure
517  */
518 static int flush(struct pl022 *pl022)
519 {
520 	unsigned long limit = loops_per_jiffy << 1;
521 
522 	dev_dbg(&pl022->adev->dev, "flush\n");
523 	do {
524 		while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
525 			readw(SSP_DR(pl022->virtbase));
526 	} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
527 
528 	pl022->exp_fifo_level = 0;
529 
530 	return limit;
531 }
532 
533 /**
534  * restore_state - Load configuration of current chip
535  * @pl022: SSP driver private data structure
536  */
537 static void restore_state(struct pl022 *pl022)
538 {
539 	struct chip_data *chip = pl022->cur_chip;
540 
541 	if (pl022->vendor->extended_cr)
542 		writel(chip->cr0, SSP_CR0(pl022->virtbase));
543 	else
544 		writew(chip->cr0, SSP_CR0(pl022->virtbase));
545 	writew(chip->cr1, SSP_CR1(pl022->virtbase));
546 	writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
547 	writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
548 	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
549 	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
550 }
551 
552 /*
553  * Default SSP Register Values
554  */
555 #define DEFAULT_SSP_REG_CR0 ( \
556 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0)	| \
557 	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
558 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
559 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
560 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
561 )
562 
563 /* ST versions have slightly different bit layout */
564 #define DEFAULT_SSP_REG_CR0_ST ( \
565 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
566 	GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
567 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
568 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
569 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
570 	GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16)	| \
571 	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
572 )
573 
574 /* The PL023 version is slightly different again */
575 #define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
576 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
577 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
578 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
579 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
580 )
581 
582 #define DEFAULT_SSP_REG_CR1 ( \
583 	GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
584 	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
585 	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
586 	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
587 )
588 
589 /* ST versions extend this register to use all 16 bits */
590 #define DEFAULT_SSP_REG_CR1_ST ( \
591 	DEFAULT_SSP_REG_CR1 | \
592 	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
593 	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
594 	GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
595 	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
596 	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
597 )
598 
599 /*
600  * The PL023 variant has further differences: no loopback mode, no microwire
601  * support, and a new clock feedback delay setting.
602  */
603 #define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
604 	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
605 	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
606 	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
607 	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
608 	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
609 	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
610 	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
611 	GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
612 )
613 
614 #define DEFAULT_SSP_REG_CPSR ( \
615 	GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
616 )
617 
618 #define DEFAULT_SSP_REG_DMACR (\
619 	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
620 	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
621 )
622 
623 /**
624  * load_ssp_default_config - Load default configuration for SSP
625  * @pl022: SSP driver private data structure
626  */
627 static void load_ssp_default_config(struct pl022 *pl022)
628 {
629 	if (pl022->vendor->pl023) {
630 		writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
631 		writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
632 	} else if (pl022->vendor->extended_cr) {
633 		writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
634 		writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
635 	} else {
636 		writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
637 		writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
638 	}
639 	writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
640 	writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
641 	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
642 	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
643 }
644 
645 /**
646  * This will write to TX and read from RX according to the parameters
647  * set in pl022.
648  */
649 static void readwriter(struct pl022 *pl022)
650 {
651 
652 	/*
653 	 * The FIFO depth is different between primecell variants.
654 	 * I believe filling in too much in the FIFO might cause
655 	 * errons in 8bit wide transfers on ARM variants (just 8 words
656 	 * FIFO, means only 8x8 = 64 bits in FIFO) at least.
657 	 *
658 	 * To prevent this issue, the TX FIFO is only filled to the
659 	 * unused RX FIFO fill length, regardless of what the TX
660 	 * FIFO status flag indicates.
661 	 */
662 	dev_dbg(&pl022->adev->dev,
663 		"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
664 		__func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
665 
666 	/* Read as much as you can */
667 	while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
668 	       && (pl022->rx < pl022->rx_end)) {
669 		switch (pl022->read) {
670 		case READING_NULL:
671 			readw(SSP_DR(pl022->virtbase));
672 			break;
673 		case READING_U8:
674 			*(u8 *) (pl022->rx) =
675 				readw(SSP_DR(pl022->virtbase)) & 0xFFU;
676 			break;
677 		case READING_U16:
678 			*(u16 *) (pl022->rx) =
679 				(u16) readw(SSP_DR(pl022->virtbase));
680 			break;
681 		case READING_U32:
682 			*(u32 *) (pl022->rx) =
683 				readl(SSP_DR(pl022->virtbase));
684 			break;
685 		}
686 		pl022->rx += (pl022->cur_chip->n_bytes);
687 		pl022->exp_fifo_level--;
688 	}
689 	/*
690 	 * Write as much as possible up to the RX FIFO size
691 	 */
692 	while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
693 	       && (pl022->tx < pl022->tx_end)) {
694 		switch (pl022->write) {
695 		case WRITING_NULL:
696 			writew(0x0, SSP_DR(pl022->virtbase));
697 			break;
698 		case WRITING_U8:
699 			writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
700 			break;
701 		case WRITING_U16:
702 			writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
703 			break;
704 		case WRITING_U32:
705 			writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
706 			break;
707 		}
708 		pl022->tx += (pl022->cur_chip->n_bytes);
709 		pl022->exp_fifo_level++;
710 		/*
711 		 * This inner reader takes care of things appearing in the RX
712 		 * FIFO as we're transmitting. This will happen a lot since the
713 		 * clock starts running when you put things into the TX FIFO,
714 		 * and then things are continuously clocked into the RX FIFO.
715 		 */
716 		while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
717 		       && (pl022->rx < pl022->rx_end)) {
718 			switch (pl022->read) {
719 			case READING_NULL:
720 				readw(SSP_DR(pl022->virtbase));
721 				break;
722 			case READING_U8:
723 				*(u8 *) (pl022->rx) =
724 					readw(SSP_DR(pl022->virtbase)) & 0xFFU;
725 				break;
726 			case READING_U16:
727 				*(u16 *) (pl022->rx) =
728 					(u16) readw(SSP_DR(pl022->virtbase));
729 				break;
730 			case READING_U32:
731 				*(u32 *) (pl022->rx) =
732 					readl(SSP_DR(pl022->virtbase));
733 				break;
734 			}
735 			pl022->rx += (pl022->cur_chip->n_bytes);
736 			pl022->exp_fifo_level--;
737 		}
738 	}
739 	/*
740 	 * When we exit here the TX FIFO should be full and the RX FIFO
741 	 * should be empty
742 	 */
743 }
744 
745 /**
746  * next_transfer - Move to the Next transfer in the current spi message
747  * @pl022: SSP driver private data structure
748  *
749  * This function moves though the linked list of spi transfers in the
750  * current spi message and returns with the state of current spi
751  * message i.e whether its last transfer is done(STATE_DONE) or
752  * Next transfer is ready(STATE_RUNNING)
753  */
754 static void *next_transfer(struct pl022 *pl022)
755 {
756 	struct spi_message *msg = pl022->cur_msg;
757 	struct spi_transfer *trans = pl022->cur_transfer;
758 
759 	/* Move to next transfer */
760 	if (trans->transfer_list.next != &msg->transfers) {
761 		pl022->cur_transfer =
762 		    list_entry(trans->transfer_list.next,
763 			       struct spi_transfer, transfer_list);
764 		return STATE_RUNNING;
765 	}
766 	return STATE_DONE;
767 }
768 
769 /*
770  * This DMA functionality is only compiled in if we have
771  * access to the generic DMA devices/DMA engine.
772  */
773 #ifdef CONFIG_DMA_ENGINE
774 static void unmap_free_dma_scatter(struct pl022 *pl022)
775 {
776 	/* Unmap and free the SG tables */
777 	dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
778 		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
779 	dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
780 		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
781 	sg_free_table(&pl022->sgt_rx);
782 	sg_free_table(&pl022->sgt_tx);
783 }
784 
785 static void dma_callback(void *data)
786 {
787 	struct pl022 *pl022 = data;
788 	struct spi_message *msg = pl022->cur_msg;
789 
790 	BUG_ON(!pl022->sgt_rx.sgl);
791 
792 #ifdef VERBOSE_DEBUG
793 	/*
794 	 * Optionally dump out buffers to inspect contents, this is
795 	 * good if you want to convince yourself that the loopback
796 	 * read/write contents are the same, when adopting to a new
797 	 * DMA engine.
798 	 */
799 	{
800 		struct scatterlist *sg;
801 		unsigned int i;
802 
803 		dma_sync_sg_for_cpu(&pl022->adev->dev,
804 				    pl022->sgt_rx.sgl,
805 				    pl022->sgt_rx.nents,
806 				    DMA_FROM_DEVICE);
807 
808 		for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
809 			dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
810 			print_hex_dump(KERN_ERR, "SPI RX: ",
811 				       DUMP_PREFIX_OFFSET,
812 				       16,
813 				       1,
814 				       sg_virt(sg),
815 				       sg_dma_len(sg),
816 				       1);
817 		}
818 		for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
819 			dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
820 			print_hex_dump(KERN_ERR, "SPI TX: ",
821 				       DUMP_PREFIX_OFFSET,
822 				       16,
823 				       1,
824 				       sg_virt(sg),
825 				       sg_dma_len(sg),
826 				       1);
827 		}
828 	}
829 #endif
830 
831 	unmap_free_dma_scatter(pl022);
832 
833 	/* Update total bytes transferred */
834 	msg->actual_length += pl022->cur_transfer->len;
835 	if (pl022->cur_transfer->cs_change)
836 		pl022_cs_control(pl022, SSP_CHIP_DESELECT);
837 
838 	/* Move to next transfer */
839 	msg->state = next_transfer(pl022);
840 	tasklet_schedule(&pl022->pump_transfers);
841 }
842 
843 static void setup_dma_scatter(struct pl022 *pl022,
844 			      void *buffer,
845 			      unsigned int length,
846 			      struct sg_table *sgtab)
847 {
848 	struct scatterlist *sg;
849 	int bytesleft = length;
850 	void *bufp = buffer;
851 	int mapbytes;
852 	int i;
853 
854 	if (buffer) {
855 		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
856 			/*
857 			 * If there are less bytes left than what fits
858 			 * in the current page (plus page alignment offset)
859 			 * we just feed in this, else we stuff in as much
860 			 * as we can.
861 			 */
862 			if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
863 				mapbytes = bytesleft;
864 			else
865 				mapbytes = PAGE_SIZE - offset_in_page(bufp);
866 			sg_set_page(sg, virt_to_page(bufp),
867 				    mapbytes, offset_in_page(bufp));
868 			bufp += mapbytes;
869 			bytesleft -= mapbytes;
870 			dev_dbg(&pl022->adev->dev,
871 				"set RX/TX target page @ %p, %d bytes, %d left\n",
872 				bufp, mapbytes, bytesleft);
873 		}
874 	} else {
875 		/* Map the dummy buffer on every page */
876 		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
877 			if (bytesleft < PAGE_SIZE)
878 				mapbytes = bytesleft;
879 			else
880 				mapbytes = PAGE_SIZE;
881 			sg_set_page(sg, virt_to_page(pl022->dummypage),
882 				    mapbytes, 0);
883 			bytesleft -= mapbytes;
884 			dev_dbg(&pl022->adev->dev,
885 				"set RX/TX to dummy page %d bytes, %d left\n",
886 				mapbytes, bytesleft);
887 
888 		}
889 	}
890 	BUG_ON(bytesleft);
891 }
892 
893 /**
894  * configure_dma - configures the channels for the next transfer
895  * @pl022: SSP driver's private data structure
896  */
897 static int configure_dma(struct pl022 *pl022)
898 {
899 	struct dma_slave_config rx_conf = {
900 		.src_addr = SSP_DR(pl022->phybase),
901 		.direction = DMA_DEV_TO_MEM,
902 		.device_fc = false,
903 	};
904 	struct dma_slave_config tx_conf = {
905 		.dst_addr = SSP_DR(pl022->phybase),
906 		.direction = DMA_MEM_TO_DEV,
907 		.device_fc = false,
908 	};
909 	unsigned int pages;
910 	int ret;
911 	int rx_sglen, tx_sglen;
912 	struct dma_chan *rxchan = pl022->dma_rx_channel;
913 	struct dma_chan *txchan = pl022->dma_tx_channel;
914 	struct dma_async_tx_descriptor *rxdesc;
915 	struct dma_async_tx_descriptor *txdesc;
916 
917 	/* Check that the channels are available */
918 	if (!rxchan || !txchan)
919 		return -ENODEV;
920 
921 	/*
922 	 * If supplied, the DMA burstsize should equal the FIFO trigger level.
923 	 * Notice that the DMA engine uses one-to-one mapping. Since we can
924 	 * not trigger on 2 elements this needs explicit mapping rather than
925 	 * calculation.
926 	 */
927 	switch (pl022->rx_lev_trig) {
928 	case SSP_RX_1_OR_MORE_ELEM:
929 		rx_conf.src_maxburst = 1;
930 		break;
931 	case SSP_RX_4_OR_MORE_ELEM:
932 		rx_conf.src_maxburst = 4;
933 		break;
934 	case SSP_RX_8_OR_MORE_ELEM:
935 		rx_conf.src_maxburst = 8;
936 		break;
937 	case SSP_RX_16_OR_MORE_ELEM:
938 		rx_conf.src_maxburst = 16;
939 		break;
940 	case SSP_RX_32_OR_MORE_ELEM:
941 		rx_conf.src_maxburst = 32;
942 		break;
943 	default:
944 		rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
945 		break;
946 	}
947 
948 	switch (pl022->tx_lev_trig) {
949 	case SSP_TX_1_OR_MORE_EMPTY_LOC:
950 		tx_conf.dst_maxburst = 1;
951 		break;
952 	case SSP_TX_4_OR_MORE_EMPTY_LOC:
953 		tx_conf.dst_maxburst = 4;
954 		break;
955 	case SSP_TX_8_OR_MORE_EMPTY_LOC:
956 		tx_conf.dst_maxburst = 8;
957 		break;
958 	case SSP_TX_16_OR_MORE_EMPTY_LOC:
959 		tx_conf.dst_maxburst = 16;
960 		break;
961 	case SSP_TX_32_OR_MORE_EMPTY_LOC:
962 		tx_conf.dst_maxburst = 32;
963 		break;
964 	default:
965 		tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
966 		break;
967 	}
968 
969 	switch (pl022->read) {
970 	case READING_NULL:
971 		/* Use the same as for writing */
972 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
973 		break;
974 	case READING_U8:
975 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
976 		break;
977 	case READING_U16:
978 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
979 		break;
980 	case READING_U32:
981 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
982 		break;
983 	}
984 
985 	switch (pl022->write) {
986 	case WRITING_NULL:
987 		/* Use the same as for reading */
988 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
989 		break;
990 	case WRITING_U8:
991 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
992 		break;
993 	case WRITING_U16:
994 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
995 		break;
996 	case WRITING_U32:
997 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
998 		break;
999 	}
1000 
1001 	/* SPI pecularity: we need to read and write the same width */
1002 	if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1003 		rx_conf.src_addr_width = tx_conf.dst_addr_width;
1004 	if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1005 		tx_conf.dst_addr_width = rx_conf.src_addr_width;
1006 	BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
1007 
1008 	dmaengine_slave_config(rxchan, &rx_conf);
1009 	dmaengine_slave_config(txchan, &tx_conf);
1010 
1011 	/* Create sglists for the transfers */
1012 	pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
1013 	dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
1014 
1015 	ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
1016 	if (ret)
1017 		goto err_alloc_rx_sg;
1018 
1019 	ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
1020 	if (ret)
1021 		goto err_alloc_tx_sg;
1022 
1023 	/* Fill in the scatterlists for the RX+TX buffers */
1024 	setup_dma_scatter(pl022, pl022->rx,
1025 			  pl022->cur_transfer->len, &pl022->sgt_rx);
1026 	setup_dma_scatter(pl022, pl022->tx,
1027 			  pl022->cur_transfer->len, &pl022->sgt_tx);
1028 
1029 	/* Map DMA buffers */
1030 	rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1031 			   pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1032 	if (!rx_sglen)
1033 		goto err_rx_sgmap;
1034 
1035 	tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1036 			   pl022->sgt_tx.nents, DMA_TO_DEVICE);
1037 	if (!tx_sglen)
1038 		goto err_tx_sgmap;
1039 
1040 	/* Send both scatterlists */
1041 	rxdesc = dmaengine_prep_slave_sg(rxchan,
1042 				      pl022->sgt_rx.sgl,
1043 				      rx_sglen,
1044 				      DMA_DEV_TO_MEM,
1045 				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1046 	if (!rxdesc)
1047 		goto err_rxdesc;
1048 
1049 	txdesc = dmaengine_prep_slave_sg(txchan,
1050 				      pl022->sgt_tx.sgl,
1051 				      tx_sglen,
1052 				      DMA_MEM_TO_DEV,
1053 				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1054 	if (!txdesc)
1055 		goto err_txdesc;
1056 
1057 	/* Put the callback on the RX transfer only, that should finish last */
1058 	rxdesc->callback = dma_callback;
1059 	rxdesc->callback_param = pl022;
1060 
1061 	/* Submit and fire RX and TX with TX last so we're ready to read! */
1062 	dmaengine_submit(rxdesc);
1063 	dmaengine_submit(txdesc);
1064 	dma_async_issue_pending(rxchan);
1065 	dma_async_issue_pending(txchan);
1066 	pl022->dma_running = true;
1067 
1068 	return 0;
1069 
1070 err_txdesc:
1071 	dmaengine_terminate_all(txchan);
1072 err_rxdesc:
1073 	dmaengine_terminate_all(rxchan);
1074 	dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1075 		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
1076 err_tx_sgmap:
1077 	dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1078 		     pl022->sgt_tx.nents, DMA_FROM_DEVICE);
1079 err_rx_sgmap:
1080 	sg_free_table(&pl022->sgt_tx);
1081 err_alloc_tx_sg:
1082 	sg_free_table(&pl022->sgt_rx);
1083 err_alloc_rx_sg:
1084 	return -ENOMEM;
1085 }
1086 
1087 static int pl022_dma_probe(struct pl022 *pl022)
1088 {
1089 	dma_cap_mask_t mask;
1090 
1091 	/* Try to acquire a generic DMA engine slave channel */
1092 	dma_cap_zero(mask);
1093 	dma_cap_set(DMA_SLAVE, mask);
1094 	/*
1095 	 * We need both RX and TX channels to do DMA, else do none
1096 	 * of them.
1097 	 */
1098 	pl022->dma_rx_channel = dma_request_channel(mask,
1099 					    pl022->master_info->dma_filter,
1100 					    pl022->master_info->dma_rx_param);
1101 	if (!pl022->dma_rx_channel) {
1102 		dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
1103 		goto err_no_rxchan;
1104 	}
1105 
1106 	pl022->dma_tx_channel = dma_request_channel(mask,
1107 					    pl022->master_info->dma_filter,
1108 					    pl022->master_info->dma_tx_param);
1109 	if (!pl022->dma_tx_channel) {
1110 		dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
1111 		goto err_no_txchan;
1112 	}
1113 
1114 	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1115 	if (!pl022->dummypage) {
1116 		dev_dbg(&pl022->adev->dev, "no DMA dummypage!\n");
1117 		goto err_no_dummypage;
1118 	}
1119 
1120 	dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
1121 		 dma_chan_name(pl022->dma_rx_channel),
1122 		 dma_chan_name(pl022->dma_tx_channel));
1123 
1124 	return 0;
1125 
1126 err_no_dummypage:
1127 	dma_release_channel(pl022->dma_tx_channel);
1128 err_no_txchan:
1129 	dma_release_channel(pl022->dma_rx_channel);
1130 	pl022->dma_rx_channel = NULL;
1131 err_no_rxchan:
1132 	dev_err(&pl022->adev->dev,
1133 			"Failed to work in dma mode, work without dma!\n");
1134 	return -ENODEV;
1135 }
1136 
1137 static int pl022_dma_autoprobe(struct pl022 *pl022)
1138 {
1139 	struct device *dev = &pl022->adev->dev;
1140 
1141 	/* automatically configure DMA channels from platform, normally using DT */
1142 	pl022->dma_rx_channel = dma_request_slave_channel(dev, "rx");
1143 	if (!pl022->dma_rx_channel)
1144 		goto err_no_rxchan;
1145 
1146 	pl022->dma_tx_channel = dma_request_slave_channel(dev, "tx");
1147 	if (!pl022->dma_tx_channel)
1148 		goto err_no_txchan;
1149 
1150 	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1151 	if (!pl022->dummypage)
1152 		goto err_no_dummypage;
1153 
1154 	return 0;
1155 
1156 err_no_dummypage:
1157 	dma_release_channel(pl022->dma_tx_channel);
1158 	pl022->dma_tx_channel = NULL;
1159 err_no_txchan:
1160 	dma_release_channel(pl022->dma_rx_channel);
1161 	pl022->dma_rx_channel = NULL;
1162 err_no_rxchan:
1163 	return -ENODEV;
1164 }
1165 
1166 static void terminate_dma(struct pl022 *pl022)
1167 {
1168 	struct dma_chan *rxchan = pl022->dma_rx_channel;
1169 	struct dma_chan *txchan = pl022->dma_tx_channel;
1170 
1171 	dmaengine_terminate_all(rxchan);
1172 	dmaengine_terminate_all(txchan);
1173 	unmap_free_dma_scatter(pl022);
1174 	pl022->dma_running = false;
1175 }
1176 
1177 static void pl022_dma_remove(struct pl022 *pl022)
1178 {
1179 	if (pl022->dma_running)
1180 		terminate_dma(pl022);
1181 	if (pl022->dma_tx_channel)
1182 		dma_release_channel(pl022->dma_tx_channel);
1183 	if (pl022->dma_rx_channel)
1184 		dma_release_channel(pl022->dma_rx_channel);
1185 	kfree(pl022->dummypage);
1186 }
1187 
1188 #else
1189 static inline int configure_dma(struct pl022 *pl022)
1190 {
1191 	return -ENODEV;
1192 }
1193 
1194 static inline int pl022_dma_autoprobe(struct pl022 *pl022)
1195 {
1196 	return 0;
1197 }
1198 
1199 static inline int pl022_dma_probe(struct pl022 *pl022)
1200 {
1201 	return 0;
1202 }
1203 
1204 static inline void pl022_dma_remove(struct pl022 *pl022)
1205 {
1206 }
1207 #endif
1208 
1209 /**
1210  * pl022_interrupt_handler - Interrupt handler for SSP controller
1211  *
1212  * This function handles interrupts generated for an interrupt based transfer.
1213  * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
1214  * current message's state as STATE_ERROR and schedule the tasklet
1215  * pump_transfers which will do the postprocessing of the current message by
1216  * calling giveback(). Otherwise it reads data from RX FIFO till there is no
1217  * more data, and writes data in TX FIFO till it is not full. If we complete
1218  * the transfer we move to the next transfer and schedule the tasklet.
1219  */
1220 static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
1221 {
1222 	struct pl022 *pl022 = dev_id;
1223 	struct spi_message *msg = pl022->cur_msg;
1224 	u16 irq_status = 0;
1225 	u16 flag = 0;
1226 
1227 	if (unlikely(!msg)) {
1228 		dev_err(&pl022->adev->dev,
1229 			"bad message state in interrupt handler");
1230 		/* Never fail */
1231 		return IRQ_HANDLED;
1232 	}
1233 
1234 	/* Read the Interrupt Status Register */
1235 	irq_status = readw(SSP_MIS(pl022->virtbase));
1236 
1237 	if (unlikely(!irq_status))
1238 		return IRQ_NONE;
1239 
1240 	/*
1241 	 * This handles the FIFO interrupts, the timeout
1242 	 * interrupts are flatly ignored, they cannot be
1243 	 * trusted.
1244 	 */
1245 	if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
1246 		/*
1247 		 * Overrun interrupt - bail out since our Data has been
1248 		 * corrupted
1249 		 */
1250 		dev_err(&pl022->adev->dev, "FIFO overrun\n");
1251 		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
1252 			dev_err(&pl022->adev->dev,
1253 				"RXFIFO is full\n");
1254 		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF)
1255 			dev_err(&pl022->adev->dev,
1256 				"TXFIFO is full\n");
1257 
1258 		/*
1259 		 * Disable and clear interrupts, disable SSP,
1260 		 * mark message with bad status so it can be
1261 		 * retried.
1262 		 */
1263 		writew(DISABLE_ALL_INTERRUPTS,
1264 		       SSP_IMSC(pl022->virtbase));
1265 		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1266 		writew((readw(SSP_CR1(pl022->virtbase)) &
1267 			(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1268 		msg->state = STATE_ERROR;
1269 
1270 		/* Schedule message queue handler */
1271 		tasklet_schedule(&pl022->pump_transfers);
1272 		return IRQ_HANDLED;
1273 	}
1274 
1275 	readwriter(pl022);
1276 
1277 	if ((pl022->tx == pl022->tx_end) && (flag == 0)) {
1278 		flag = 1;
1279 		/* Disable Transmit interrupt, enable receive interrupt */
1280 		writew((readw(SSP_IMSC(pl022->virtbase)) &
1281 		       ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
1282 		       SSP_IMSC(pl022->virtbase));
1283 	}
1284 
1285 	/*
1286 	 * Since all transactions must write as much as shall be read,
1287 	 * we can conclude the entire transaction once RX is complete.
1288 	 * At this point, all TX will always be finished.
1289 	 */
1290 	if (pl022->rx >= pl022->rx_end) {
1291 		writew(DISABLE_ALL_INTERRUPTS,
1292 		       SSP_IMSC(pl022->virtbase));
1293 		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1294 		if (unlikely(pl022->rx > pl022->rx_end)) {
1295 			dev_warn(&pl022->adev->dev, "read %u surplus "
1296 				 "bytes (did you request an odd "
1297 				 "number of bytes on a 16bit bus?)\n",
1298 				 (u32) (pl022->rx - pl022->rx_end));
1299 		}
1300 		/* Update total bytes transferred */
1301 		msg->actual_length += pl022->cur_transfer->len;
1302 		if (pl022->cur_transfer->cs_change)
1303 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1304 		/* Move to next transfer */
1305 		msg->state = next_transfer(pl022);
1306 		tasklet_schedule(&pl022->pump_transfers);
1307 		return IRQ_HANDLED;
1308 	}
1309 
1310 	return IRQ_HANDLED;
1311 }
1312 
1313 /**
1314  * This sets up the pointers to memory for the next message to
1315  * send out on the SPI bus.
1316  */
1317 static int set_up_next_transfer(struct pl022 *pl022,
1318 				struct spi_transfer *transfer)
1319 {
1320 	int residue;
1321 
1322 	/* Sanity check the message for this bus width */
1323 	residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
1324 	if (unlikely(residue != 0)) {
1325 		dev_err(&pl022->adev->dev,
1326 			"message of %u bytes to transmit but the current "
1327 			"chip bus has a data width of %u bytes!\n",
1328 			pl022->cur_transfer->len,
1329 			pl022->cur_chip->n_bytes);
1330 		dev_err(&pl022->adev->dev, "skipping this message\n");
1331 		return -EIO;
1332 	}
1333 	pl022->tx = (void *)transfer->tx_buf;
1334 	pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
1335 	pl022->rx = (void *)transfer->rx_buf;
1336 	pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
1337 	pl022->write =
1338 	    pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
1339 	pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
1340 	return 0;
1341 }
1342 
1343 /**
1344  * pump_transfers - Tasklet function which schedules next transfer
1345  * when running in interrupt or DMA transfer mode.
1346  * @data: SSP driver private data structure
1347  *
1348  */
1349 static void pump_transfers(unsigned long data)
1350 {
1351 	struct pl022 *pl022 = (struct pl022 *) data;
1352 	struct spi_message *message = NULL;
1353 	struct spi_transfer *transfer = NULL;
1354 	struct spi_transfer *previous = NULL;
1355 
1356 	/* Get current state information */
1357 	message = pl022->cur_msg;
1358 	transfer = pl022->cur_transfer;
1359 
1360 	/* Handle for abort */
1361 	if (message->state == STATE_ERROR) {
1362 		message->status = -EIO;
1363 		giveback(pl022);
1364 		return;
1365 	}
1366 
1367 	/* Handle end of message */
1368 	if (message->state == STATE_DONE) {
1369 		message->status = 0;
1370 		giveback(pl022);
1371 		return;
1372 	}
1373 
1374 	/* Delay if requested at end of transfer before CS change */
1375 	if (message->state == STATE_RUNNING) {
1376 		previous = list_entry(transfer->transfer_list.prev,
1377 					struct spi_transfer,
1378 					transfer_list);
1379 		if (previous->delay_usecs)
1380 			/*
1381 			 * FIXME: This runs in interrupt context.
1382 			 * Is this really smart?
1383 			 */
1384 			udelay(previous->delay_usecs);
1385 
1386 		/* Reselect chip select only if cs_change was requested */
1387 		if (previous->cs_change)
1388 			pl022_cs_control(pl022, SSP_CHIP_SELECT);
1389 	} else {
1390 		/* STATE_START */
1391 		message->state = STATE_RUNNING;
1392 	}
1393 
1394 	if (set_up_next_transfer(pl022, transfer)) {
1395 		message->state = STATE_ERROR;
1396 		message->status = -EIO;
1397 		giveback(pl022);
1398 		return;
1399 	}
1400 	/* Flush the FIFOs and let's go! */
1401 	flush(pl022);
1402 
1403 	if (pl022->cur_chip->enable_dma) {
1404 		if (configure_dma(pl022)) {
1405 			dev_dbg(&pl022->adev->dev,
1406 				"configuration of DMA failed, fall back to interrupt mode\n");
1407 			goto err_config_dma;
1408 		}
1409 		return;
1410 	}
1411 
1412 err_config_dma:
1413 	/* enable all interrupts except RX */
1414 	writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase));
1415 }
1416 
1417 static void do_interrupt_dma_transfer(struct pl022 *pl022)
1418 {
1419 	/*
1420 	 * Default is to enable all interrupts except RX -
1421 	 * this will be enabled once TX is complete
1422 	 */
1423 	u32 irqflags = ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM;
1424 
1425 	/* Enable target chip, if not already active */
1426 	if (!pl022->next_msg_cs_active)
1427 		pl022_cs_control(pl022, SSP_CHIP_SELECT);
1428 
1429 	if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
1430 		/* Error path */
1431 		pl022->cur_msg->state = STATE_ERROR;
1432 		pl022->cur_msg->status = -EIO;
1433 		giveback(pl022);
1434 		return;
1435 	}
1436 	/* If we're using DMA, set up DMA here */
1437 	if (pl022->cur_chip->enable_dma) {
1438 		/* Configure DMA transfer */
1439 		if (configure_dma(pl022)) {
1440 			dev_dbg(&pl022->adev->dev,
1441 				"configuration of DMA failed, fall back to interrupt mode\n");
1442 			goto err_config_dma;
1443 		}
1444 		/* Disable interrupts in DMA mode, IRQ from DMA controller */
1445 		irqflags = DISABLE_ALL_INTERRUPTS;
1446 	}
1447 err_config_dma:
1448 	/* Enable SSP, turn on interrupts */
1449 	writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1450 	       SSP_CR1(pl022->virtbase));
1451 	writew(irqflags, SSP_IMSC(pl022->virtbase));
1452 }
1453 
1454 static void do_polling_transfer(struct pl022 *pl022)
1455 {
1456 	struct spi_message *message = NULL;
1457 	struct spi_transfer *transfer = NULL;
1458 	struct spi_transfer *previous = NULL;
1459 	struct chip_data *chip;
1460 	unsigned long time, timeout;
1461 
1462 	chip = pl022->cur_chip;
1463 	message = pl022->cur_msg;
1464 
1465 	while (message->state != STATE_DONE) {
1466 		/* Handle for abort */
1467 		if (message->state == STATE_ERROR)
1468 			break;
1469 		transfer = pl022->cur_transfer;
1470 
1471 		/* Delay if requested at end of transfer */
1472 		if (message->state == STATE_RUNNING) {
1473 			previous =
1474 			    list_entry(transfer->transfer_list.prev,
1475 				       struct spi_transfer, transfer_list);
1476 			if (previous->delay_usecs)
1477 				udelay(previous->delay_usecs);
1478 			if (previous->cs_change)
1479 				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1480 		} else {
1481 			/* STATE_START */
1482 			message->state = STATE_RUNNING;
1483 			if (!pl022->next_msg_cs_active)
1484 				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1485 		}
1486 
1487 		/* Configuration Changing Per Transfer */
1488 		if (set_up_next_transfer(pl022, transfer)) {
1489 			/* Error path */
1490 			message->state = STATE_ERROR;
1491 			break;
1492 		}
1493 		/* Flush FIFOs and enable SSP */
1494 		flush(pl022);
1495 		writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1496 		       SSP_CR1(pl022->virtbase));
1497 
1498 		dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
1499 
1500 		timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
1501 		while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
1502 			time = jiffies;
1503 			readwriter(pl022);
1504 			if (time_after(time, timeout)) {
1505 				dev_warn(&pl022->adev->dev,
1506 				"%s: timeout!\n", __func__);
1507 				message->state = STATE_ERROR;
1508 				goto out;
1509 			}
1510 			cpu_relax();
1511 		}
1512 
1513 		/* Update total byte transferred */
1514 		message->actual_length += pl022->cur_transfer->len;
1515 		if (pl022->cur_transfer->cs_change)
1516 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1517 		/* Move to next transfer */
1518 		message->state = next_transfer(pl022);
1519 	}
1520 out:
1521 	/* Handle end of message */
1522 	if (message->state == STATE_DONE)
1523 		message->status = 0;
1524 	else
1525 		message->status = -EIO;
1526 
1527 	giveback(pl022);
1528 	return;
1529 }
1530 
1531 static int pl022_transfer_one_message(struct spi_master *master,
1532 				      struct spi_message *msg)
1533 {
1534 	struct pl022 *pl022 = spi_master_get_devdata(master);
1535 
1536 	/* Initial message state */
1537 	pl022->cur_msg = msg;
1538 	msg->state = STATE_START;
1539 
1540 	pl022->cur_transfer = list_entry(msg->transfers.next,
1541 					 struct spi_transfer, transfer_list);
1542 
1543 	/* Setup the SPI using the per chip configuration */
1544 	pl022->cur_chip = spi_get_ctldata(msg->spi);
1545 	pl022->cur_cs = pl022->chipselects[msg->spi->chip_select];
1546 
1547 	restore_state(pl022);
1548 	flush(pl022);
1549 
1550 	if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
1551 		do_polling_transfer(pl022);
1552 	else
1553 		do_interrupt_dma_transfer(pl022);
1554 
1555 	return 0;
1556 }
1557 
1558 static int pl022_prepare_transfer_hardware(struct spi_master *master)
1559 {
1560 	struct pl022 *pl022 = spi_master_get_devdata(master);
1561 
1562 	/*
1563 	 * Just make sure we have all we need to run the transfer by syncing
1564 	 * with the runtime PM framework.
1565 	 */
1566 	pm_runtime_get_sync(&pl022->adev->dev);
1567 	return 0;
1568 }
1569 
1570 static int pl022_unprepare_transfer_hardware(struct spi_master *master)
1571 {
1572 	struct pl022 *pl022 = spi_master_get_devdata(master);
1573 
1574 	/* nothing more to do - disable spi/ssp and power off */
1575 	writew((readw(SSP_CR1(pl022->virtbase)) &
1576 		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1577 
1578 	if (pl022->master_info->autosuspend_delay > 0) {
1579 		pm_runtime_mark_last_busy(&pl022->adev->dev);
1580 		pm_runtime_put_autosuspend(&pl022->adev->dev);
1581 	} else {
1582 		pm_runtime_put(&pl022->adev->dev);
1583 	}
1584 
1585 	return 0;
1586 }
1587 
1588 static int verify_controller_parameters(struct pl022 *pl022,
1589 				struct pl022_config_chip const *chip_info)
1590 {
1591 	if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
1592 	    || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
1593 		dev_err(&pl022->adev->dev,
1594 			"interface is configured incorrectly\n");
1595 		return -EINVAL;
1596 	}
1597 	if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
1598 	    (!pl022->vendor->unidir)) {
1599 		dev_err(&pl022->adev->dev,
1600 			"unidirectional mode not supported in this "
1601 			"hardware version\n");
1602 		return -EINVAL;
1603 	}
1604 	if ((chip_info->hierarchy != SSP_MASTER)
1605 	    && (chip_info->hierarchy != SSP_SLAVE)) {
1606 		dev_err(&pl022->adev->dev,
1607 			"hierarchy is configured incorrectly\n");
1608 		return -EINVAL;
1609 	}
1610 	if ((chip_info->com_mode != INTERRUPT_TRANSFER)
1611 	    && (chip_info->com_mode != DMA_TRANSFER)
1612 	    && (chip_info->com_mode != POLLING_TRANSFER)) {
1613 		dev_err(&pl022->adev->dev,
1614 			"Communication mode is configured incorrectly\n");
1615 		return -EINVAL;
1616 	}
1617 	switch (chip_info->rx_lev_trig) {
1618 	case SSP_RX_1_OR_MORE_ELEM:
1619 	case SSP_RX_4_OR_MORE_ELEM:
1620 	case SSP_RX_8_OR_MORE_ELEM:
1621 		/* These are always OK, all variants can handle this */
1622 		break;
1623 	case SSP_RX_16_OR_MORE_ELEM:
1624 		if (pl022->vendor->fifodepth < 16) {
1625 			dev_err(&pl022->adev->dev,
1626 			"RX FIFO Trigger Level is configured incorrectly\n");
1627 			return -EINVAL;
1628 		}
1629 		break;
1630 	case SSP_RX_32_OR_MORE_ELEM:
1631 		if (pl022->vendor->fifodepth < 32) {
1632 			dev_err(&pl022->adev->dev,
1633 			"RX FIFO Trigger Level is configured incorrectly\n");
1634 			return -EINVAL;
1635 		}
1636 		break;
1637 	default:
1638 		dev_err(&pl022->adev->dev,
1639 			"RX FIFO Trigger Level is configured incorrectly\n");
1640 		return -EINVAL;
1641 		break;
1642 	}
1643 	switch (chip_info->tx_lev_trig) {
1644 	case SSP_TX_1_OR_MORE_EMPTY_LOC:
1645 	case SSP_TX_4_OR_MORE_EMPTY_LOC:
1646 	case SSP_TX_8_OR_MORE_EMPTY_LOC:
1647 		/* These are always OK, all variants can handle this */
1648 		break;
1649 	case SSP_TX_16_OR_MORE_EMPTY_LOC:
1650 		if (pl022->vendor->fifodepth < 16) {
1651 			dev_err(&pl022->adev->dev,
1652 			"TX FIFO Trigger Level is configured incorrectly\n");
1653 			return -EINVAL;
1654 		}
1655 		break;
1656 	case SSP_TX_32_OR_MORE_EMPTY_LOC:
1657 		if (pl022->vendor->fifodepth < 32) {
1658 			dev_err(&pl022->adev->dev,
1659 			"TX FIFO Trigger Level is configured incorrectly\n");
1660 			return -EINVAL;
1661 		}
1662 		break;
1663 	default:
1664 		dev_err(&pl022->adev->dev,
1665 			"TX FIFO Trigger Level is configured incorrectly\n");
1666 		return -EINVAL;
1667 		break;
1668 	}
1669 	if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
1670 		if ((chip_info->ctrl_len < SSP_BITS_4)
1671 		    || (chip_info->ctrl_len > SSP_BITS_32)) {
1672 			dev_err(&pl022->adev->dev,
1673 				"CTRL LEN is configured incorrectly\n");
1674 			return -EINVAL;
1675 		}
1676 		if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
1677 		    && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
1678 			dev_err(&pl022->adev->dev,
1679 				"Wait State is configured incorrectly\n");
1680 			return -EINVAL;
1681 		}
1682 		/* Half duplex is only available in the ST Micro version */
1683 		if (pl022->vendor->extended_cr) {
1684 			if ((chip_info->duplex !=
1685 			     SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1686 			    && (chip_info->duplex !=
1687 				SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
1688 				dev_err(&pl022->adev->dev,
1689 					"Microwire duplex mode is configured incorrectly\n");
1690 				return -EINVAL;
1691 			}
1692 		} else {
1693 			if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1694 				dev_err(&pl022->adev->dev,
1695 					"Microwire half duplex mode requested,"
1696 					" but this is only available in the"
1697 					" ST version of PL022\n");
1698 			return -EINVAL;
1699 		}
1700 	}
1701 	return 0;
1702 }
1703 
1704 static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
1705 {
1706 	return rate / (cpsdvsr * (1 + scr));
1707 }
1708 
1709 static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
1710 				    ssp_clock_params * clk_freq)
1711 {
1712 	/* Lets calculate the frequency parameters */
1713 	u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
1714 	u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
1715 		best_scr = 0, tmp, found = 0;
1716 
1717 	rate = clk_get_rate(pl022->clk);
1718 	/* cpsdvscr = 2 & scr 0 */
1719 	max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
1720 	/* cpsdvsr = 254 & scr = 255 */
1721 	min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
1722 
1723 	if (freq > max_tclk)
1724 		dev_warn(&pl022->adev->dev,
1725 			"Max speed that can be programmed is %d Hz, you requested %d\n",
1726 			max_tclk, freq);
1727 
1728 	if (freq < min_tclk) {
1729 		dev_err(&pl022->adev->dev,
1730 			"Requested frequency: %d Hz is less than minimum possible %d Hz\n",
1731 			freq, min_tclk);
1732 		return -EINVAL;
1733 	}
1734 
1735 	/*
1736 	 * best_freq will give closest possible available rate (<= requested
1737 	 * freq) for all values of scr & cpsdvsr.
1738 	 */
1739 	while ((cpsdvsr <= CPSDVR_MAX) && !found) {
1740 		while (scr <= SCR_MAX) {
1741 			tmp = spi_rate(rate, cpsdvsr, scr);
1742 
1743 			if (tmp > freq) {
1744 				/* we need lower freq */
1745 				scr++;
1746 				continue;
1747 			}
1748 
1749 			/*
1750 			 * If found exact value, mark found and break.
1751 			 * If found more closer value, update and break.
1752 			 */
1753 			if (tmp > best_freq) {
1754 				best_freq = tmp;
1755 				best_cpsdvsr = cpsdvsr;
1756 				best_scr = scr;
1757 
1758 				if (tmp == freq)
1759 					found = 1;
1760 			}
1761 			/*
1762 			 * increased scr will give lower rates, which are not
1763 			 * required
1764 			 */
1765 			break;
1766 		}
1767 		cpsdvsr += 2;
1768 		scr = SCR_MIN;
1769 	}
1770 
1771 	WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
1772 			freq);
1773 
1774 	clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
1775 	clk_freq->scr = (u8) (best_scr & 0xFF);
1776 	dev_dbg(&pl022->adev->dev,
1777 		"SSP Target Frequency is: %u, Effective Frequency is %u\n",
1778 		freq, best_freq);
1779 	dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
1780 		clk_freq->cpsdvsr, clk_freq->scr);
1781 
1782 	return 0;
1783 }
1784 
1785 /*
1786  * A piece of default chip info unless the platform
1787  * supplies it.
1788  */
1789 static const struct pl022_config_chip pl022_default_chip_info = {
1790 	.com_mode = POLLING_TRANSFER,
1791 	.iface = SSP_INTERFACE_MOTOROLA_SPI,
1792 	.hierarchy = SSP_SLAVE,
1793 	.slave_tx_disable = DO_NOT_DRIVE_TX,
1794 	.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
1795 	.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
1796 	.ctrl_len = SSP_BITS_8,
1797 	.wait_state = SSP_MWIRE_WAIT_ZERO,
1798 	.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
1799 	.cs_control = null_cs_control,
1800 };
1801 
1802 /**
1803  * pl022_setup - setup function registered to SPI master framework
1804  * @spi: spi device which is requesting setup
1805  *
1806  * This function is registered to the SPI framework for this SPI master
1807  * controller. If it is the first time when setup is called by this device,
1808  * this function will initialize the runtime state for this chip and save
1809  * the same in the device structure. Else it will update the runtime info
1810  * with the updated chip info. Nothing is really being written to the
1811  * controller hardware here, that is not done until the actual transfer
1812  * commence.
1813  */
1814 static int pl022_setup(struct spi_device *spi)
1815 {
1816 	struct pl022_config_chip const *chip_info;
1817 	struct pl022_config_chip chip_info_dt;
1818 	struct chip_data *chip;
1819 	struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
1820 	int status = 0;
1821 	struct pl022 *pl022 = spi_master_get_devdata(spi->master);
1822 	unsigned int bits = spi->bits_per_word;
1823 	u32 tmp;
1824 	struct device_node *np = spi->dev.of_node;
1825 
1826 	if (!spi->max_speed_hz)
1827 		return -EINVAL;
1828 
1829 	/* Get controller_state if one is supplied */
1830 	chip = spi_get_ctldata(spi);
1831 
1832 	if (chip == NULL) {
1833 		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1834 		if (!chip) {
1835 			dev_err(&spi->dev,
1836 				"cannot allocate controller state\n");
1837 			return -ENOMEM;
1838 		}
1839 		dev_dbg(&spi->dev,
1840 			"allocated memory for controller's runtime state\n");
1841 	}
1842 
1843 	/* Get controller data if one is supplied */
1844 	chip_info = spi->controller_data;
1845 
1846 	if (chip_info == NULL) {
1847 		if (np) {
1848 			chip_info_dt = pl022_default_chip_info;
1849 
1850 			chip_info_dt.hierarchy = SSP_MASTER;
1851 			of_property_read_u32(np, "pl022,interface",
1852 				&chip_info_dt.iface);
1853 			of_property_read_u32(np, "pl022,com-mode",
1854 				&chip_info_dt.com_mode);
1855 			of_property_read_u32(np, "pl022,rx-level-trig",
1856 				&chip_info_dt.rx_lev_trig);
1857 			of_property_read_u32(np, "pl022,tx-level-trig",
1858 				&chip_info_dt.tx_lev_trig);
1859 			of_property_read_u32(np, "pl022,ctrl-len",
1860 				&chip_info_dt.ctrl_len);
1861 			of_property_read_u32(np, "pl022,wait-state",
1862 				&chip_info_dt.wait_state);
1863 			of_property_read_u32(np, "pl022,duplex",
1864 				&chip_info_dt.duplex);
1865 
1866 			chip_info = &chip_info_dt;
1867 		} else {
1868 			chip_info = &pl022_default_chip_info;
1869 			/* spi_board_info.controller_data not is supplied */
1870 			dev_dbg(&spi->dev,
1871 				"using default controller_data settings\n");
1872 		}
1873 	} else
1874 		dev_dbg(&spi->dev,
1875 			"using user supplied controller_data settings\n");
1876 
1877 	/*
1878 	 * We can override with custom divisors, else we use the board
1879 	 * frequency setting
1880 	 */
1881 	if ((0 == chip_info->clk_freq.cpsdvsr)
1882 	    && (0 == chip_info->clk_freq.scr)) {
1883 		status = calculate_effective_freq(pl022,
1884 						  spi->max_speed_hz,
1885 						  &clk_freq);
1886 		if (status < 0)
1887 			goto err_config_params;
1888 	} else {
1889 		memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
1890 		if ((clk_freq.cpsdvsr % 2) != 0)
1891 			clk_freq.cpsdvsr =
1892 				clk_freq.cpsdvsr - 1;
1893 	}
1894 	if ((clk_freq.cpsdvsr < CPSDVR_MIN)
1895 	    || (clk_freq.cpsdvsr > CPSDVR_MAX)) {
1896 		status = -EINVAL;
1897 		dev_err(&spi->dev,
1898 			"cpsdvsr is configured incorrectly\n");
1899 		goto err_config_params;
1900 	}
1901 
1902 	status = verify_controller_parameters(pl022, chip_info);
1903 	if (status) {
1904 		dev_err(&spi->dev, "controller data is incorrect");
1905 		goto err_config_params;
1906 	}
1907 
1908 	pl022->rx_lev_trig = chip_info->rx_lev_trig;
1909 	pl022->tx_lev_trig = chip_info->tx_lev_trig;
1910 
1911 	/* Now set controller state based on controller data */
1912 	chip->xfer_type = chip_info->com_mode;
1913 	if (!chip_info->cs_control) {
1914 		chip->cs_control = null_cs_control;
1915 		if (!gpio_is_valid(pl022->chipselects[spi->chip_select]))
1916 			dev_warn(&spi->dev,
1917 				 "invalid chip select\n");
1918 	} else
1919 		chip->cs_control = chip_info->cs_control;
1920 
1921 	/* Check bits per word with vendor specific range */
1922 	if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
1923 		status = -ENOTSUPP;
1924 		dev_err(&spi->dev, "illegal data size for this controller!\n");
1925 		dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
1926 				pl022->vendor->max_bpw);
1927 		goto err_config_params;
1928 	} else if (bits <= 8) {
1929 		dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
1930 		chip->n_bytes = 1;
1931 		chip->read = READING_U8;
1932 		chip->write = WRITING_U8;
1933 	} else if (bits <= 16) {
1934 		dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
1935 		chip->n_bytes = 2;
1936 		chip->read = READING_U16;
1937 		chip->write = WRITING_U16;
1938 	} else {
1939 		dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
1940 		chip->n_bytes = 4;
1941 		chip->read = READING_U32;
1942 		chip->write = WRITING_U32;
1943 	}
1944 
1945 	/* Now Initialize all register settings required for this chip */
1946 	chip->cr0 = 0;
1947 	chip->cr1 = 0;
1948 	chip->dmacr = 0;
1949 	chip->cpsr = 0;
1950 	if ((chip_info->com_mode == DMA_TRANSFER)
1951 	    && ((pl022->master_info)->enable_dma)) {
1952 		chip->enable_dma = true;
1953 		dev_dbg(&spi->dev, "DMA mode set in controller state\n");
1954 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1955 			       SSP_DMACR_MASK_RXDMAE, 0);
1956 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1957 			       SSP_DMACR_MASK_TXDMAE, 1);
1958 	} else {
1959 		chip->enable_dma = false;
1960 		dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
1961 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1962 			       SSP_DMACR_MASK_RXDMAE, 0);
1963 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1964 			       SSP_DMACR_MASK_TXDMAE, 1);
1965 	}
1966 
1967 	chip->cpsr = clk_freq.cpsdvsr;
1968 
1969 	/* Special setup for the ST micro extended control registers */
1970 	if (pl022->vendor->extended_cr) {
1971 		u32 etx;
1972 
1973 		if (pl022->vendor->pl023) {
1974 			/* These bits are only in the PL023 */
1975 			SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
1976 				       SSP_CR1_MASK_FBCLKDEL_ST, 13);
1977 		} else {
1978 			/* These bits are in the PL022 but not PL023 */
1979 			SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
1980 				       SSP_CR0_MASK_HALFDUP_ST, 5);
1981 			SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
1982 				       SSP_CR0_MASK_CSS_ST, 16);
1983 			SSP_WRITE_BITS(chip->cr0, chip_info->iface,
1984 				       SSP_CR0_MASK_FRF_ST, 21);
1985 			SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
1986 				       SSP_CR1_MASK_MWAIT_ST, 6);
1987 		}
1988 		SSP_WRITE_BITS(chip->cr0, bits - 1,
1989 			       SSP_CR0_MASK_DSS_ST, 0);
1990 
1991 		if (spi->mode & SPI_LSB_FIRST) {
1992 			tmp = SSP_RX_LSB;
1993 			etx = SSP_TX_LSB;
1994 		} else {
1995 			tmp = SSP_RX_MSB;
1996 			etx = SSP_TX_MSB;
1997 		}
1998 		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
1999 		SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
2000 		SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
2001 			       SSP_CR1_MASK_RXIFLSEL_ST, 7);
2002 		SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
2003 			       SSP_CR1_MASK_TXIFLSEL_ST, 10);
2004 	} else {
2005 		SSP_WRITE_BITS(chip->cr0, bits - 1,
2006 			       SSP_CR0_MASK_DSS, 0);
2007 		SSP_WRITE_BITS(chip->cr0, chip_info->iface,
2008 			       SSP_CR0_MASK_FRF, 4);
2009 	}
2010 
2011 	/* Stuff that is common for all versions */
2012 	if (spi->mode & SPI_CPOL)
2013 		tmp = SSP_CLK_POL_IDLE_HIGH;
2014 	else
2015 		tmp = SSP_CLK_POL_IDLE_LOW;
2016 	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
2017 
2018 	if (spi->mode & SPI_CPHA)
2019 		tmp = SSP_CLK_SECOND_EDGE;
2020 	else
2021 		tmp = SSP_CLK_FIRST_EDGE;
2022 	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
2023 
2024 	SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
2025 	/* Loopback is available on all versions except PL023 */
2026 	if (pl022->vendor->loopback) {
2027 		if (spi->mode & SPI_LOOP)
2028 			tmp = LOOPBACK_ENABLED;
2029 		else
2030 			tmp = LOOPBACK_DISABLED;
2031 		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
2032 	}
2033 	SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
2034 	SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
2035 	SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
2036 		3);
2037 
2038 	/* Save controller_state */
2039 	spi_set_ctldata(spi, chip);
2040 	return status;
2041  err_config_params:
2042 	spi_set_ctldata(spi, NULL);
2043 	kfree(chip);
2044 	return status;
2045 }
2046 
2047 /**
2048  * pl022_cleanup - cleanup function registered to SPI master framework
2049  * @spi: spi device which is requesting cleanup
2050  *
2051  * This function is registered to the SPI framework for this SPI master
2052  * controller. It will free the runtime state of chip.
2053  */
2054 static void pl022_cleanup(struct spi_device *spi)
2055 {
2056 	struct chip_data *chip = spi_get_ctldata(spi);
2057 
2058 	spi_set_ctldata(spi, NULL);
2059 	kfree(chip);
2060 }
2061 
2062 static struct pl022_ssp_controller *
2063 pl022_platform_data_dt_get(struct device *dev)
2064 {
2065 	struct device_node *np = dev->of_node;
2066 	struct pl022_ssp_controller *pd;
2067 	u32 tmp;
2068 
2069 	if (!np) {
2070 		dev_err(dev, "no dt node defined\n");
2071 		return NULL;
2072 	}
2073 
2074 	pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
2075 	if (!pd) {
2076 		dev_err(dev, "cannot allocate platform data memory\n");
2077 		return NULL;
2078 	}
2079 
2080 	pd->bus_id = -1;
2081 	pd->enable_dma = 1;
2082 	of_property_read_u32(np, "num-cs", &tmp);
2083 	pd->num_chipselect = tmp;
2084 	of_property_read_u32(np, "pl022,autosuspend-delay",
2085 			     &pd->autosuspend_delay);
2086 	pd->rt = of_property_read_bool(np, "pl022,rt");
2087 
2088 	return pd;
2089 }
2090 
2091 static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
2092 {
2093 	struct device *dev = &adev->dev;
2094 	struct pl022_ssp_controller *platform_info = adev->dev.platform_data;
2095 	struct spi_master *master;
2096 	struct pl022 *pl022 = NULL;	/*Data for this driver */
2097 	struct device_node *np = adev->dev.of_node;
2098 	int status = 0, i, num_cs;
2099 
2100 	dev_info(&adev->dev,
2101 		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
2102 	if (!platform_info && IS_ENABLED(CONFIG_OF))
2103 		platform_info = pl022_platform_data_dt_get(dev);
2104 
2105 	if (!platform_info) {
2106 		dev_err(dev, "probe: no platform data defined\n");
2107 		return -ENODEV;
2108 	}
2109 
2110 	if (platform_info->num_chipselect) {
2111 		num_cs = platform_info->num_chipselect;
2112 	} else {
2113 		dev_err(dev, "probe: no chip select defined\n");
2114 		return -ENODEV;
2115 	}
2116 
2117 	/* Allocate master with space for data */
2118 	master = spi_alloc_master(dev, sizeof(struct pl022));
2119 	if (master == NULL) {
2120 		dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
2121 		return -ENOMEM;
2122 	}
2123 
2124 	pl022 = spi_master_get_devdata(master);
2125 	pl022->master = master;
2126 	pl022->master_info = platform_info;
2127 	pl022->adev = adev;
2128 	pl022->vendor = id->data;
2129 	pl022->chipselects = devm_kzalloc(dev, num_cs * sizeof(int),
2130 					  GFP_KERNEL);
2131 
2132 	pinctrl_pm_select_default_state(dev);
2133 
2134 	/*
2135 	 * Bus Number Which has been Assigned to this SSP controller
2136 	 * on this board
2137 	 */
2138 	master->bus_num = platform_info->bus_id;
2139 	master->num_chipselect = num_cs;
2140 	master->cleanup = pl022_cleanup;
2141 	master->setup = pl022_setup;
2142 	master->prepare_transfer_hardware = pl022_prepare_transfer_hardware;
2143 	master->transfer_one_message = pl022_transfer_one_message;
2144 	master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
2145 	master->rt = platform_info->rt;
2146 	master->dev.of_node = dev->of_node;
2147 
2148 	if (platform_info->num_chipselect && platform_info->chipselects) {
2149 		for (i = 0; i < num_cs; i++)
2150 			pl022->chipselects[i] = platform_info->chipselects[i];
2151 	} else if (IS_ENABLED(CONFIG_OF)) {
2152 		for (i = 0; i < num_cs; i++) {
2153 			int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
2154 
2155 			if (cs_gpio == -EPROBE_DEFER) {
2156 				status = -EPROBE_DEFER;
2157 				goto err_no_gpio;
2158 			}
2159 
2160 			pl022->chipselects[i] = cs_gpio;
2161 
2162 			if (gpio_is_valid(cs_gpio)) {
2163 				if (devm_gpio_request(dev, cs_gpio, "ssp-pl022"))
2164 					dev_err(&adev->dev,
2165 						"could not request %d gpio\n",
2166 						cs_gpio);
2167 				else if (gpio_direction_output(cs_gpio, 1))
2168 					dev_err(&adev->dev,
2169 						"could set gpio %d as output\n",
2170 						cs_gpio);
2171 			}
2172 		}
2173 	}
2174 
2175 	/*
2176 	 * Supports mode 0-3, loopback, and active low CS. Transfers are
2177 	 * always MS bit first on the original pl022.
2178 	 */
2179 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
2180 	if (pl022->vendor->extended_cr)
2181 		master->mode_bits |= SPI_LSB_FIRST;
2182 
2183 	dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
2184 
2185 	status = amba_request_regions(adev, NULL);
2186 	if (status)
2187 		goto err_no_ioregion;
2188 
2189 	pl022->phybase = adev->res.start;
2190 	pl022->virtbase = devm_ioremap(dev, adev->res.start,
2191 				       resource_size(&adev->res));
2192 	if (pl022->virtbase == NULL) {
2193 		status = -ENOMEM;
2194 		goto err_no_ioremap;
2195 	}
2196 	printk(KERN_INFO "pl022: mapped registers from 0x%08x to %p\n",
2197 	       adev->res.start, pl022->virtbase);
2198 
2199 	pl022->clk = devm_clk_get(&adev->dev, NULL);
2200 	if (IS_ERR(pl022->clk)) {
2201 		status = PTR_ERR(pl022->clk);
2202 		dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
2203 		goto err_no_clk;
2204 	}
2205 
2206 	status = clk_prepare(pl022->clk);
2207 	if (status) {
2208 		dev_err(&adev->dev, "could not prepare SSP/SPI bus clock\n");
2209 		goto  err_clk_prep;
2210 	}
2211 
2212 	status = clk_enable(pl022->clk);
2213 	if (status) {
2214 		dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
2215 		goto err_no_clk_en;
2216 	}
2217 
2218 	/* Initialize transfer pump */
2219 	tasklet_init(&pl022->pump_transfers, pump_transfers,
2220 		     (unsigned long)pl022);
2221 
2222 	/* Disable SSP */
2223 	writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
2224 	       SSP_CR1(pl022->virtbase));
2225 	load_ssp_default_config(pl022);
2226 
2227 	status = devm_request_irq(dev, adev->irq[0], pl022_interrupt_handler,
2228 				  0, "pl022", pl022);
2229 	if (status < 0) {
2230 		dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
2231 		goto err_no_irq;
2232 	}
2233 
2234 	/* Get DMA channels, try autoconfiguration first */
2235 	status = pl022_dma_autoprobe(pl022);
2236 
2237 	/* If that failed, use channels from platform_info */
2238 	if (status == 0)
2239 		platform_info->enable_dma = 1;
2240 	else if (platform_info->enable_dma) {
2241 		status = pl022_dma_probe(pl022);
2242 		if (status != 0)
2243 			platform_info->enable_dma = 0;
2244 	}
2245 
2246 	/* Register with the SPI framework */
2247 	amba_set_drvdata(adev, pl022);
2248 	status = spi_register_master(master);
2249 	if (status != 0) {
2250 		dev_err(&adev->dev,
2251 			"probe - problem registering spi master\n");
2252 		goto err_spi_register;
2253 	}
2254 	dev_dbg(dev, "probe succeeded\n");
2255 
2256 	/* let runtime pm put suspend */
2257 	if (platform_info->autosuspend_delay > 0) {
2258 		dev_info(&adev->dev,
2259 			"will use autosuspend for runtime pm, delay %dms\n",
2260 			platform_info->autosuspend_delay);
2261 		pm_runtime_set_autosuspend_delay(dev,
2262 			platform_info->autosuspend_delay);
2263 		pm_runtime_use_autosuspend(dev);
2264 	}
2265 	pm_runtime_put(dev);
2266 
2267 	return 0;
2268 
2269  err_spi_register:
2270 	if (platform_info->enable_dma)
2271 		pl022_dma_remove(pl022);
2272  err_no_irq:
2273 	clk_disable(pl022->clk);
2274  err_no_clk_en:
2275 	clk_unprepare(pl022->clk);
2276  err_clk_prep:
2277  err_no_clk:
2278  err_no_ioremap:
2279 	amba_release_regions(adev);
2280  err_no_ioregion:
2281  err_no_gpio:
2282 	spi_master_put(master);
2283 	return status;
2284 }
2285 
2286 static int
2287 pl022_remove(struct amba_device *adev)
2288 {
2289 	struct pl022 *pl022 = amba_get_drvdata(adev);
2290 
2291 	if (!pl022)
2292 		return 0;
2293 
2294 	/*
2295 	 * undo pm_runtime_put() in probe.  I assume that we're not
2296 	 * accessing the primecell here.
2297 	 */
2298 	pm_runtime_get_noresume(&adev->dev);
2299 
2300 	load_ssp_default_config(pl022);
2301 	if (pl022->master_info->enable_dma)
2302 		pl022_dma_remove(pl022);
2303 
2304 	clk_disable(pl022->clk);
2305 	clk_unprepare(pl022->clk);
2306 	amba_release_regions(adev);
2307 	tasklet_disable(&pl022->pump_transfers);
2308 	spi_unregister_master(pl022->master);
2309 	amba_set_drvdata(adev, NULL);
2310 	return 0;
2311 }
2312 
2313 #if defined(CONFIG_SUSPEND) || defined(CONFIG_PM_RUNTIME)
2314 /*
2315  * These two functions are used from both suspend/resume and
2316  * the runtime counterparts to handle external resources like
2317  * clocks, pins and regulators when going to sleep.
2318  */
2319 static void pl022_suspend_resources(struct pl022 *pl022, bool runtime)
2320 {
2321 	clk_disable(pl022->clk);
2322 
2323 	if (runtime)
2324 		pinctrl_pm_select_idle_state(&pl022->adev->dev);
2325 	else
2326 		pinctrl_pm_select_sleep_state(&pl022->adev->dev);
2327 }
2328 
2329 static void pl022_resume_resources(struct pl022 *pl022, bool runtime)
2330 {
2331 	/* First go to the default state */
2332 	pinctrl_pm_select_default_state(&pl022->adev->dev);
2333 	if (!runtime)
2334 		/* Then let's idle the pins until the next transfer happens */
2335 		pinctrl_pm_select_idle_state(&pl022->adev->dev);
2336 
2337 	clk_enable(pl022->clk);
2338 }
2339 #endif
2340 
2341 #ifdef CONFIG_SUSPEND
2342 static int pl022_suspend(struct device *dev)
2343 {
2344 	struct pl022 *pl022 = dev_get_drvdata(dev);
2345 	int ret;
2346 
2347 	ret = spi_master_suspend(pl022->master);
2348 	if (ret) {
2349 		dev_warn(dev, "cannot suspend master\n");
2350 		return ret;
2351 	}
2352 
2353 	pm_runtime_get_sync(dev);
2354 	pl022_suspend_resources(pl022, false);
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 	pl022_resume_resources(pl022, false);
2366 	pm_runtime_put(dev);
2367 
2368 	/* Start the queue running */
2369 	ret = spi_master_resume(pl022->master);
2370 	if (ret)
2371 		dev_err(dev, "problem starting queue (%d)\n", ret);
2372 	else
2373 		dev_dbg(dev, "resumed\n");
2374 
2375 	return ret;
2376 }
2377 #endif	/* CONFIG_PM */
2378 
2379 #ifdef CONFIG_PM_RUNTIME
2380 static int pl022_runtime_suspend(struct device *dev)
2381 {
2382 	struct pl022 *pl022 = dev_get_drvdata(dev);
2383 
2384 	pl022_suspend_resources(pl022, true);
2385 	return 0;
2386 }
2387 
2388 static int pl022_runtime_resume(struct device *dev)
2389 {
2390 	struct pl022 *pl022 = dev_get_drvdata(dev);
2391 
2392 	pl022_resume_resources(pl022, true);
2393 	return 0;
2394 }
2395 #endif
2396 
2397 static const struct dev_pm_ops pl022_dev_pm_ops = {
2398 	SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
2399 	SET_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
2400 };
2401 
2402 static struct vendor_data vendor_arm = {
2403 	.fifodepth = 8,
2404 	.max_bpw = 16,
2405 	.unidir = false,
2406 	.extended_cr = false,
2407 	.pl023 = false,
2408 	.loopback = true,
2409 };
2410 
2411 static struct vendor_data vendor_st = {
2412 	.fifodepth = 32,
2413 	.max_bpw = 32,
2414 	.unidir = false,
2415 	.extended_cr = true,
2416 	.pl023 = false,
2417 	.loopback = true,
2418 };
2419 
2420 static struct vendor_data vendor_st_pl023 = {
2421 	.fifodepth = 32,
2422 	.max_bpw = 32,
2423 	.unidir = false,
2424 	.extended_cr = true,
2425 	.pl023 = true,
2426 	.loopback = false,
2427 };
2428 
2429 static struct amba_id pl022_ids[] = {
2430 	{
2431 		/*
2432 		 * ARM PL022 variant, this has a 16bit wide
2433 		 * and 8 locations deep TX/RX FIFO
2434 		 */
2435 		.id	= 0x00041022,
2436 		.mask	= 0x000fffff,
2437 		.data	= &vendor_arm,
2438 	},
2439 	{
2440 		/*
2441 		 * ST Micro derivative, this has 32bit wide
2442 		 * and 32 locations deep TX/RX FIFO
2443 		 */
2444 		.id	= 0x01080022,
2445 		.mask	= 0xffffffff,
2446 		.data	= &vendor_st,
2447 	},
2448 	{
2449 		/*
2450 		 * ST-Ericsson derivative "PL023" (this is not
2451 		 * an official ARM number), this is a PL022 SSP block
2452 		 * stripped to SPI mode only, it has 32bit wide
2453 		 * and 32 locations deep TX/RX FIFO but no extended
2454 		 * CR0/CR1 register
2455 		 */
2456 		.id	= 0x00080023,
2457 		.mask	= 0xffffffff,
2458 		.data	= &vendor_st_pl023,
2459 	},
2460 	{ 0, 0 },
2461 };
2462 
2463 MODULE_DEVICE_TABLE(amba, pl022_ids);
2464 
2465 static struct amba_driver pl022_driver = {
2466 	.drv = {
2467 		.name	= "ssp-pl022",
2468 		.pm	= &pl022_dev_pm_ops,
2469 	},
2470 	.id_table	= pl022_ids,
2471 	.probe		= pl022_probe,
2472 	.remove		= pl022_remove,
2473 };
2474 
2475 static int __init pl022_init(void)
2476 {
2477 	return amba_driver_register(&pl022_driver);
2478 }
2479 subsys_initcall(pl022_init);
2480 
2481 static void __exit pl022_exit(void)
2482 {
2483 	amba_driver_unregister(&pl022_driver);
2484 }
2485 module_exit(pl022_exit);
2486 
2487 MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
2488 MODULE_DESCRIPTION("PL022 SSP Controller Driver");
2489 MODULE_LICENSE("GPL");
2490