xref: /linux/drivers/spi/spi-s3c64xx.c (revision e21f9e2e862e9eb3dd64eaddb6256b3e5098660f)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Copyright (c) 2009 Samsung Electronics Co., Ltd.
4 //      Jaswinder Singh <jassi.brar@samsung.com>
5 
6 #include <linux/init.h>
7 #include <linux/module.h>
8 #include <linux/interrupt.h>
9 #include <linux/delay.h>
10 #include <linux/clk.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/dmaengine.h>
13 #include <linux/platform_device.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/spi/spi.h>
16 #include <linux/gpio.h>
17 #include <linux/of.h>
18 #include <linux/of_gpio.h>
19 
20 #include <linux/platform_data/spi-s3c64xx.h>
21 
22 #define MAX_SPI_PORTS		6
23 #define S3C64XX_SPI_QUIRK_POLL		(1 << 0)
24 #define S3C64XX_SPI_QUIRK_CS_AUTO	(1 << 1)
25 #define AUTOSUSPEND_TIMEOUT	2000
26 
27 /* Registers and bit-fields */
28 
29 #define S3C64XX_SPI_CH_CFG		0x00
30 #define S3C64XX_SPI_CLK_CFG		0x04
31 #define S3C64XX_SPI_MODE_CFG	0x08
32 #define S3C64XX_SPI_SLAVE_SEL	0x0C
33 #define S3C64XX_SPI_INT_EN		0x10
34 #define S3C64XX_SPI_STATUS		0x14
35 #define S3C64XX_SPI_TX_DATA		0x18
36 #define S3C64XX_SPI_RX_DATA		0x1C
37 #define S3C64XX_SPI_PACKET_CNT	0x20
38 #define S3C64XX_SPI_PENDING_CLR	0x24
39 #define S3C64XX_SPI_SWAP_CFG	0x28
40 #define S3C64XX_SPI_FB_CLK		0x2C
41 
42 #define S3C64XX_SPI_CH_HS_EN		(1<<6)	/* High Speed Enable */
43 #define S3C64XX_SPI_CH_SW_RST		(1<<5)
44 #define S3C64XX_SPI_CH_SLAVE		(1<<4)
45 #define S3C64XX_SPI_CPOL_L		(1<<3)
46 #define S3C64XX_SPI_CPHA_B		(1<<2)
47 #define S3C64XX_SPI_CH_RXCH_ON		(1<<1)
48 #define S3C64XX_SPI_CH_TXCH_ON		(1<<0)
49 
50 #define S3C64XX_SPI_CLKSEL_SRCMSK	(3<<9)
51 #define S3C64XX_SPI_CLKSEL_SRCSHFT	9
52 #define S3C64XX_SPI_ENCLK_ENABLE	(1<<8)
53 #define S3C64XX_SPI_PSR_MASK		0xff
54 
55 #define S3C64XX_SPI_MODE_CH_TSZ_BYTE		(0<<29)
56 #define S3C64XX_SPI_MODE_CH_TSZ_HALFWORD	(1<<29)
57 #define S3C64XX_SPI_MODE_CH_TSZ_WORD		(2<<29)
58 #define S3C64XX_SPI_MODE_CH_TSZ_MASK		(3<<29)
59 #define S3C64XX_SPI_MODE_BUS_TSZ_BYTE		(0<<17)
60 #define S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD	(1<<17)
61 #define S3C64XX_SPI_MODE_BUS_TSZ_WORD		(2<<17)
62 #define S3C64XX_SPI_MODE_BUS_TSZ_MASK		(3<<17)
63 #define S3C64XX_SPI_MODE_RXDMA_ON		(1<<2)
64 #define S3C64XX_SPI_MODE_TXDMA_ON		(1<<1)
65 #define S3C64XX_SPI_MODE_4BURST			(1<<0)
66 
67 #define S3C64XX_SPI_SLAVE_AUTO			(1<<1)
68 #define S3C64XX_SPI_SLAVE_SIG_INACT		(1<<0)
69 #define S3C64XX_SPI_SLAVE_NSC_CNT_2		(2<<4)
70 
71 #define S3C64XX_SPI_INT_TRAILING_EN		(1<<6)
72 #define S3C64XX_SPI_INT_RX_OVERRUN_EN		(1<<5)
73 #define S3C64XX_SPI_INT_RX_UNDERRUN_EN		(1<<4)
74 #define S3C64XX_SPI_INT_TX_OVERRUN_EN		(1<<3)
75 #define S3C64XX_SPI_INT_TX_UNDERRUN_EN		(1<<2)
76 #define S3C64XX_SPI_INT_RX_FIFORDY_EN		(1<<1)
77 #define S3C64XX_SPI_INT_TX_FIFORDY_EN		(1<<0)
78 
79 #define S3C64XX_SPI_ST_RX_OVERRUN_ERR		(1<<5)
80 #define S3C64XX_SPI_ST_RX_UNDERRUN_ERR	(1<<4)
81 #define S3C64XX_SPI_ST_TX_OVERRUN_ERR		(1<<3)
82 #define S3C64XX_SPI_ST_TX_UNDERRUN_ERR	(1<<2)
83 #define S3C64XX_SPI_ST_RX_FIFORDY		(1<<1)
84 #define S3C64XX_SPI_ST_TX_FIFORDY		(1<<0)
85 
86 #define S3C64XX_SPI_PACKET_CNT_EN		(1<<16)
87 
88 #define S3C64XX_SPI_PND_TX_UNDERRUN_CLR		(1<<4)
89 #define S3C64XX_SPI_PND_TX_OVERRUN_CLR		(1<<3)
90 #define S3C64XX_SPI_PND_RX_UNDERRUN_CLR		(1<<2)
91 #define S3C64XX_SPI_PND_RX_OVERRUN_CLR		(1<<1)
92 #define S3C64XX_SPI_PND_TRAILING_CLR		(1<<0)
93 
94 #define S3C64XX_SPI_SWAP_RX_HALF_WORD		(1<<7)
95 #define S3C64XX_SPI_SWAP_RX_BYTE		(1<<6)
96 #define S3C64XX_SPI_SWAP_RX_BIT			(1<<5)
97 #define S3C64XX_SPI_SWAP_RX_EN			(1<<4)
98 #define S3C64XX_SPI_SWAP_TX_HALF_WORD		(1<<3)
99 #define S3C64XX_SPI_SWAP_TX_BYTE		(1<<2)
100 #define S3C64XX_SPI_SWAP_TX_BIT			(1<<1)
101 #define S3C64XX_SPI_SWAP_TX_EN			(1<<0)
102 
103 #define S3C64XX_SPI_FBCLK_MSK		(3<<0)
104 
105 #define FIFO_LVL_MASK(i) ((i)->port_conf->fifo_lvl_mask[i->port_id])
106 #define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & \
107 				(1 << (i)->port_conf->tx_st_done)) ? 1 : 0)
108 #define TX_FIFO_LVL(v, i) (((v) >> 6) & FIFO_LVL_MASK(i))
109 #define RX_FIFO_LVL(v, i) (((v) >> (i)->port_conf->rx_lvl_offset) & \
110 					FIFO_LVL_MASK(i))
111 
112 #define S3C64XX_SPI_MAX_TRAILCNT	0x3ff
113 #define S3C64XX_SPI_TRAILCNT_OFF	19
114 
115 #define S3C64XX_SPI_TRAILCNT		S3C64XX_SPI_MAX_TRAILCNT
116 
117 #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
118 #define is_polling(x)	(x->port_conf->quirks & S3C64XX_SPI_QUIRK_POLL)
119 
120 #define RXBUSY    (1<<2)
121 #define TXBUSY    (1<<3)
122 
123 struct s3c64xx_spi_dma_data {
124 	struct dma_chan *ch;
125 	enum dma_transfer_direction direction;
126 };
127 
128 /**
129  * struct s3c64xx_spi_info - SPI Controller hardware info
130  * @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
131  * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
132  * @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
133  * @high_speed: True, if the controller supports HIGH_SPEED_EN bit.
134  * @clk_from_cmu: True, if the controller does not include a clock mux and
135  *	prescaler unit.
136  *
137  * The Samsung s3c64xx SPI controller are used on various Samsung SoC's but
138  * differ in some aspects such as the size of the fifo and spi bus clock
139  * setup. Such differences are specified to the driver using this structure
140  * which is provided as driver data to the driver.
141  */
142 struct s3c64xx_spi_port_config {
143 	int	fifo_lvl_mask[MAX_SPI_PORTS];
144 	int	rx_lvl_offset;
145 	int	tx_st_done;
146 	int	quirks;
147 	bool	high_speed;
148 	bool	clk_from_cmu;
149 	bool	clk_ioclk;
150 };
151 
152 /**
153  * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
154  * @clk: Pointer to the spi clock.
155  * @src_clk: Pointer to the clock used to generate SPI signals.
156  * @ioclk: Pointer to the i/o clock between master and slave
157  * @master: Pointer to the SPI Protocol master.
158  * @cntrlr_info: Platform specific data for the controller this driver manages.
159  * @tgl_spi: Pointer to the last CS left untoggled by the cs_change hint.
160  * @lock: Controller specific lock.
161  * @state: Set of FLAGS to indicate status.
162  * @rx_dmach: Controller's DMA channel for Rx.
163  * @tx_dmach: Controller's DMA channel for Tx.
164  * @sfr_start: BUS address of SPI controller regs.
165  * @regs: Pointer to ioremap'ed controller registers.
166  * @irq: interrupt
167  * @xfer_completion: To indicate completion of xfer task.
168  * @cur_mode: Stores the active configuration of the controller.
169  * @cur_bpw: Stores the active bits per word settings.
170  * @cur_speed: Stores the active xfer clock speed.
171  */
172 struct s3c64xx_spi_driver_data {
173 	void __iomem                    *regs;
174 	struct clk                      *clk;
175 	struct clk                      *src_clk;
176 	struct clk                      *ioclk;
177 	struct platform_device          *pdev;
178 	struct spi_master               *master;
179 	struct s3c64xx_spi_info  *cntrlr_info;
180 	struct spi_device               *tgl_spi;
181 	spinlock_t                      lock;
182 	unsigned long                   sfr_start;
183 	struct completion               xfer_completion;
184 	unsigned                        state;
185 	unsigned                        cur_mode, cur_bpw;
186 	unsigned                        cur_speed;
187 	struct s3c64xx_spi_dma_data	rx_dma;
188 	struct s3c64xx_spi_dma_data	tx_dma;
189 	struct s3c64xx_spi_port_config	*port_conf;
190 	unsigned int			port_id;
191 };
192 
193 static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
194 {
195 	void __iomem *regs = sdd->regs;
196 	unsigned long loops;
197 	u32 val;
198 
199 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
200 
201 	val = readl(regs + S3C64XX_SPI_CH_CFG);
202 	val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON);
203 	writel(val, regs + S3C64XX_SPI_CH_CFG);
204 
205 	val = readl(regs + S3C64XX_SPI_CH_CFG);
206 	val |= S3C64XX_SPI_CH_SW_RST;
207 	val &= ~S3C64XX_SPI_CH_HS_EN;
208 	writel(val, regs + S3C64XX_SPI_CH_CFG);
209 
210 	/* Flush TxFIFO*/
211 	loops = msecs_to_loops(1);
212 	do {
213 		val = readl(regs + S3C64XX_SPI_STATUS);
214 	} while (TX_FIFO_LVL(val, sdd) && loops--);
215 
216 	if (loops == 0)
217 		dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n");
218 
219 	/* Flush RxFIFO*/
220 	loops = msecs_to_loops(1);
221 	do {
222 		val = readl(regs + S3C64XX_SPI_STATUS);
223 		if (RX_FIFO_LVL(val, sdd))
224 			readl(regs + S3C64XX_SPI_RX_DATA);
225 		else
226 			break;
227 	} while (loops--);
228 
229 	if (loops == 0)
230 		dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n");
231 
232 	val = readl(regs + S3C64XX_SPI_CH_CFG);
233 	val &= ~S3C64XX_SPI_CH_SW_RST;
234 	writel(val, regs + S3C64XX_SPI_CH_CFG);
235 
236 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
237 	val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
238 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
239 }
240 
241 static void s3c64xx_spi_dmacb(void *data)
242 {
243 	struct s3c64xx_spi_driver_data *sdd;
244 	struct s3c64xx_spi_dma_data *dma = data;
245 	unsigned long flags;
246 
247 	if (dma->direction == DMA_DEV_TO_MEM)
248 		sdd = container_of(data,
249 			struct s3c64xx_spi_driver_data, rx_dma);
250 	else
251 		sdd = container_of(data,
252 			struct s3c64xx_spi_driver_data, tx_dma);
253 
254 	spin_lock_irqsave(&sdd->lock, flags);
255 
256 	if (dma->direction == DMA_DEV_TO_MEM) {
257 		sdd->state &= ~RXBUSY;
258 		if (!(sdd->state & TXBUSY))
259 			complete(&sdd->xfer_completion);
260 	} else {
261 		sdd->state &= ~TXBUSY;
262 		if (!(sdd->state & RXBUSY))
263 			complete(&sdd->xfer_completion);
264 	}
265 
266 	spin_unlock_irqrestore(&sdd->lock, flags);
267 }
268 
269 static void prepare_dma(struct s3c64xx_spi_dma_data *dma,
270 			struct sg_table *sgt)
271 {
272 	struct s3c64xx_spi_driver_data *sdd;
273 	struct dma_slave_config config;
274 	struct dma_async_tx_descriptor *desc;
275 
276 	memset(&config, 0, sizeof(config));
277 
278 	if (dma->direction == DMA_DEV_TO_MEM) {
279 		sdd = container_of((void *)dma,
280 			struct s3c64xx_spi_driver_data, rx_dma);
281 		config.direction = dma->direction;
282 		config.src_addr = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
283 		config.src_addr_width = sdd->cur_bpw / 8;
284 		config.src_maxburst = 1;
285 		dmaengine_slave_config(dma->ch, &config);
286 	} else {
287 		sdd = container_of((void *)dma,
288 			struct s3c64xx_spi_driver_data, tx_dma);
289 		config.direction = dma->direction;
290 		config.dst_addr = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
291 		config.dst_addr_width = sdd->cur_bpw / 8;
292 		config.dst_maxburst = 1;
293 		dmaengine_slave_config(dma->ch, &config);
294 	}
295 
296 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
297 				       dma->direction, DMA_PREP_INTERRUPT);
298 
299 	desc->callback = s3c64xx_spi_dmacb;
300 	desc->callback_param = dma;
301 
302 	dmaengine_submit(desc);
303 	dma_async_issue_pending(dma->ch);
304 }
305 
306 static void s3c64xx_spi_set_cs(struct spi_device *spi, bool enable)
307 {
308 	struct s3c64xx_spi_driver_data *sdd =
309 					spi_master_get_devdata(spi->master);
310 
311 	if (sdd->cntrlr_info->no_cs)
312 		return;
313 
314 	if (enable) {
315 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO)) {
316 			writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
317 		} else {
318 			u32 ssel = readl(sdd->regs + S3C64XX_SPI_SLAVE_SEL);
319 
320 			ssel |= (S3C64XX_SPI_SLAVE_AUTO |
321 						S3C64XX_SPI_SLAVE_NSC_CNT_2);
322 			writel(ssel, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
323 		}
324 	} else {
325 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
326 			writel(S3C64XX_SPI_SLAVE_SIG_INACT,
327 			       sdd->regs + S3C64XX_SPI_SLAVE_SEL);
328 	}
329 }
330 
331 static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
332 {
333 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
334 
335 	if (is_polling(sdd))
336 		return 0;
337 
338 	spi->dma_rx = sdd->rx_dma.ch;
339 	spi->dma_tx = sdd->tx_dma.ch;
340 
341 	return 0;
342 }
343 
344 static bool s3c64xx_spi_can_dma(struct spi_master *master,
345 				struct spi_device *spi,
346 				struct spi_transfer *xfer)
347 {
348 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
349 
350 	return xfer->len > (FIFO_LVL_MASK(sdd) >> 1) + 1;
351 }
352 
353 static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
354 				struct spi_device *spi,
355 				struct spi_transfer *xfer, int dma_mode)
356 {
357 	void __iomem *regs = sdd->regs;
358 	u32 modecfg, chcfg;
359 
360 	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
361 	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
362 
363 	chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
364 	chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
365 
366 	if (dma_mode) {
367 		chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
368 	} else {
369 		/* Always shift in data in FIFO, even if xfer is Tx only,
370 		 * this helps setting PCKT_CNT value for generating clocks
371 		 * as exactly needed.
372 		 */
373 		chcfg |= S3C64XX_SPI_CH_RXCH_ON;
374 		writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
375 					| S3C64XX_SPI_PACKET_CNT_EN,
376 					regs + S3C64XX_SPI_PACKET_CNT);
377 	}
378 
379 	if (xfer->tx_buf != NULL) {
380 		sdd->state |= TXBUSY;
381 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
382 		if (dma_mode) {
383 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
384 			prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
385 		} else {
386 			switch (sdd->cur_bpw) {
387 			case 32:
388 				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
389 					xfer->tx_buf, xfer->len / 4);
390 				break;
391 			case 16:
392 				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
393 					xfer->tx_buf, xfer->len / 2);
394 				break;
395 			default:
396 				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
397 					xfer->tx_buf, xfer->len);
398 				break;
399 			}
400 		}
401 	}
402 
403 	if (xfer->rx_buf != NULL) {
404 		sdd->state |= RXBUSY;
405 
406 		if (sdd->port_conf->high_speed && sdd->cur_speed >= 30000000UL
407 					&& !(sdd->cur_mode & SPI_CPHA))
408 			chcfg |= S3C64XX_SPI_CH_HS_EN;
409 
410 		if (dma_mode) {
411 			modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
412 			chcfg |= S3C64XX_SPI_CH_RXCH_ON;
413 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
414 					| S3C64XX_SPI_PACKET_CNT_EN,
415 					regs + S3C64XX_SPI_PACKET_CNT);
416 			prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
417 		}
418 	}
419 
420 	writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
421 	writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
422 }
423 
424 static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
425 					int timeout_ms)
426 {
427 	void __iomem *regs = sdd->regs;
428 	unsigned long val = 1;
429 	u32 status;
430 
431 	/* max fifo depth available */
432 	u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
433 
434 	if (timeout_ms)
435 		val = msecs_to_loops(timeout_ms);
436 
437 	do {
438 		status = readl(regs + S3C64XX_SPI_STATUS);
439 	} while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
440 
441 	/* return the actual received data length */
442 	return RX_FIFO_LVL(status, sdd);
443 }
444 
445 static int wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
446 			struct spi_transfer *xfer)
447 {
448 	void __iomem *regs = sdd->regs;
449 	unsigned long val;
450 	u32 status;
451 	int ms;
452 
453 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
454 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
455 	ms += 10; /* some tolerance */
456 
457 	val = msecs_to_jiffies(ms) + 10;
458 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
459 
460 	/*
461 	 * If the previous xfer was completed within timeout, then
462 	 * proceed further else return -EIO.
463 	 * DmaTx returns after simply writing data in the FIFO,
464 	 * w/o waiting for real transmission on the bus to finish.
465 	 * DmaRx returns only after Dma read data from FIFO which
466 	 * needs bus transmission to finish, so we don't worry if
467 	 * Xfer involved Rx(with or without Tx).
468 	 */
469 	if (val && !xfer->rx_buf) {
470 		val = msecs_to_loops(10);
471 		status = readl(regs + S3C64XX_SPI_STATUS);
472 		while ((TX_FIFO_LVL(status, sdd)
473 			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
474 		       && --val) {
475 			cpu_relax();
476 			status = readl(regs + S3C64XX_SPI_STATUS);
477 		}
478 
479 	}
480 
481 	/* If timed out while checking rx/tx status return error */
482 	if (!val)
483 		return -EIO;
484 
485 	return 0;
486 }
487 
488 static int wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
489 			struct spi_transfer *xfer)
490 {
491 	void __iomem *regs = sdd->regs;
492 	unsigned long val;
493 	u32 status;
494 	int loops;
495 	u32 cpy_len;
496 	u8 *buf;
497 	int ms;
498 
499 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
500 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
501 	ms += 10; /* some tolerance */
502 
503 	val = msecs_to_loops(ms);
504 	do {
505 		status = readl(regs + S3C64XX_SPI_STATUS);
506 	} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
507 
508 
509 	/* If it was only Tx */
510 	if (!xfer->rx_buf) {
511 		sdd->state &= ~TXBUSY;
512 		return 0;
513 	}
514 
515 	/*
516 	 * If the receive length is bigger than the controller fifo
517 	 * size, calculate the loops and read the fifo as many times.
518 	 * loops = length / max fifo size (calculated by using the
519 	 * fifo mask).
520 	 * For any size less than the fifo size the below code is
521 	 * executed atleast once.
522 	 */
523 	loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
524 	buf = xfer->rx_buf;
525 	do {
526 		/* wait for data to be received in the fifo */
527 		cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
528 						       (loops ? ms : 0));
529 
530 		switch (sdd->cur_bpw) {
531 		case 32:
532 			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
533 				     buf, cpy_len / 4);
534 			break;
535 		case 16:
536 			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
537 				     buf, cpy_len / 2);
538 			break;
539 		default:
540 			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
541 				    buf, cpy_len);
542 			break;
543 		}
544 
545 		buf = buf + cpy_len;
546 	} while (loops--);
547 	sdd->state &= ~RXBUSY;
548 
549 	return 0;
550 }
551 
552 static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
553 {
554 	void __iomem *regs = sdd->regs;
555 	u32 val;
556 
557 	/* Disable Clock */
558 	if (!sdd->port_conf->clk_from_cmu) {
559 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
560 		val &= ~S3C64XX_SPI_ENCLK_ENABLE;
561 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
562 	}
563 
564 	/* Set Polarity and Phase */
565 	val = readl(regs + S3C64XX_SPI_CH_CFG);
566 	val &= ~(S3C64XX_SPI_CH_SLAVE |
567 			S3C64XX_SPI_CPOL_L |
568 			S3C64XX_SPI_CPHA_B);
569 
570 	if (sdd->cur_mode & SPI_CPOL)
571 		val |= S3C64XX_SPI_CPOL_L;
572 
573 	if (sdd->cur_mode & SPI_CPHA)
574 		val |= S3C64XX_SPI_CPHA_B;
575 
576 	writel(val, regs + S3C64XX_SPI_CH_CFG);
577 
578 	/* Set Channel & DMA Mode */
579 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
580 	val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
581 			| S3C64XX_SPI_MODE_CH_TSZ_MASK);
582 
583 	switch (sdd->cur_bpw) {
584 	case 32:
585 		val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
586 		val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;
587 		break;
588 	case 16:
589 		val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
590 		val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;
591 		break;
592 	default:
593 		val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
594 		val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;
595 		break;
596 	}
597 
598 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
599 
600 	if (sdd->port_conf->clk_from_cmu) {
601 		/* The src_clk clock is divided internally by 2 */
602 		clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
603 	} else {
604 		/* Configure Clock */
605 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
606 		val &= ~S3C64XX_SPI_PSR_MASK;
607 		val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1)
608 				& S3C64XX_SPI_PSR_MASK);
609 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
610 
611 		/* Enable Clock */
612 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
613 		val |= S3C64XX_SPI_ENCLK_ENABLE;
614 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
615 	}
616 }
617 
618 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
619 
620 static int s3c64xx_spi_prepare_message(struct spi_master *master,
621 				       struct spi_message *msg)
622 {
623 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
624 	struct spi_device *spi = msg->spi;
625 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
626 
627 	/* Configure feedback delay */
628 	writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
629 
630 	return 0;
631 }
632 
633 static int s3c64xx_spi_transfer_one(struct spi_master *master,
634 				    struct spi_device *spi,
635 				    struct spi_transfer *xfer)
636 {
637 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
638 	int status;
639 	u32 speed;
640 	u8 bpw;
641 	unsigned long flags;
642 	int use_dma;
643 
644 	reinit_completion(&sdd->xfer_completion);
645 
646 	/* Only BPW and Speed may change across transfers */
647 	bpw = xfer->bits_per_word;
648 	speed = xfer->speed_hz;
649 
650 	if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
651 		sdd->cur_bpw = bpw;
652 		sdd->cur_speed = speed;
653 		sdd->cur_mode = spi->mode;
654 		s3c64xx_spi_config(sdd);
655 	}
656 
657 	/* Polling method for xfers not bigger than FIFO capacity */
658 	use_dma = 0;
659 	if (!is_polling(sdd) &&
660 	    (sdd->rx_dma.ch && sdd->tx_dma.ch &&
661 	     (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1))))
662 		use_dma = 1;
663 
664 	spin_lock_irqsave(&sdd->lock, flags);
665 
666 	/* Pending only which is to be done */
667 	sdd->state &= ~RXBUSY;
668 	sdd->state &= ~TXBUSY;
669 
670 	enable_datapath(sdd, spi, xfer, use_dma);
671 
672 	/* Start the signals */
673 	s3c64xx_spi_set_cs(spi, true);
674 
675 	spin_unlock_irqrestore(&sdd->lock, flags);
676 
677 	if (use_dma)
678 		status = wait_for_dma(sdd, xfer);
679 	else
680 		status = wait_for_pio(sdd, xfer);
681 
682 	if (status) {
683 		dev_err(&spi->dev, "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
684 			xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
685 			(sdd->state & RXBUSY) ? 'f' : 'p',
686 			(sdd->state & TXBUSY) ? 'f' : 'p',
687 			xfer->len);
688 
689 		if (use_dma) {
690 			if (xfer->tx_buf != NULL
691 			    && (sdd->state & TXBUSY))
692 				dmaengine_terminate_all(sdd->tx_dma.ch);
693 			if (xfer->rx_buf != NULL
694 			    && (sdd->state & RXBUSY))
695 				dmaengine_terminate_all(sdd->rx_dma.ch);
696 		}
697 	} else {
698 		flush_fifo(sdd);
699 	}
700 
701 	return status;
702 }
703 
704 static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
705 				struct spi_device *spi)
706 {
707 	struct s3c64xx_spi_csinfo *cs;
708 	struct device_node *slave_np, *data_np = NULL;
709 	u32 fb_delay = 0;
710 
711 	slave_np = spi->dev.of_node;
712 	if (!slave_np) {
713 		dev_err(&spi->dev, "device node not found\n");
714 		return ERR_PTR(-EINVAL);
715 	}
716 
717 	data_np = of_get_child_by_name(slave_np, "controller-data");
718 	if (!data_np) {
719 		dev_err(&spi->dev, "child node 'controller-data' not found\n");
720 		return ERR_PTR(-EINVAL);
721 	}
722 
723 	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
724 	if (!cs) {
725 		of_node_put(data_np);
726 		return ERR_PTR(-ENOMEM);
727 	}
728 
729 	of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
730 	cs->fb_delay = fb_delay;
731 	of_node_put(data_np);
732 	return cs;
733 }
734 
735 /*
736  * Here we only check the validity of requested configuration
737  * and save the configuration in a local data-structure.
738  * The controller is actually configured only just before we
739  * get a message to transfer.
740  */
741 static int s3c64xx_spi_setup(struct spi_device *spi)
742 {
743 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
744 	struct s3c64xx_spi_driver_data *sdd;
745 	int err;
746 
747 	sdd = spi_master_get_devdata(spi->master);
748 	if (spi->dev.of_node) {
749 		cs = s3c64xx_get_slave_ctrldata(spi);
750 		spi->controller_data = cs;
751 	} else if (cs) {
752 		/* On non-DT platforms the SPI core will set spi->cs_gpio
753 		 * to -ENOENT. The GPIO pin used to drive the chip select
754 		 * is defined by using platform data so spi->cs_gpio value
755 		 * has to be override to have the proper GPIO pin number.
756 		 */
757 		spi->cs_gpio = cs->line;
758 	}
759 
760 	if (IS_ERR_OR_NULL(cs)) {
761 		dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
762 		return -ENODEV;
763 	}
764 
765 	if (!spi_get_ctldata(spi)) {
766 		if (gpio_is_valid(spi->cs_gpio)) {
767 			err = gpio_request_one(spi->cs_gpio, GPIOF_OUT_INIT_HIGH,
768 					       dev_name(&spi->dev));
769 			if (err) {
770 				dev_err(&spi->dev,
771 					"Failed to get /CS gpio [%d]: %d\n",
772 					spi->cs_gpio, err);
773 				goto err_gpio_req;
774 			}
775 		}
776 
777 		spi_set_ctldata(spi, cs);
778 	}
779 
780 	pm_runtime_get_sync(&sdd->pdev->dev);
781 
782 	/* Check if we can provide the requested rate */
783 	if (!sdd->port_conf->clk_from_cmu) {
784 		u32 psr, speed;
785 
786 		/* Max possible */
787 		speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1);
788 
789 		if (spi->max_speed_hz > speed)
790 			spi->max_speed_hz = speed;
791 
792 		psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1;
793 		psr &= S3C64XX_SPI_PSR_MASK;
794 		if (psr == S3C64XX_SPI_PSR_MASK)
795 			psr--;
796 
797 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
798 		if (spi->max_speed_hz < speed) {
799 			if (psr+1 < S3C64XX_SPI_PSR_MASK) {
800 				psr++;
801 			} else {
802 				err = -EINVAL;
803 				goto setup_exit;
804 			}
805 		}
806 
807 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
808 		if (spi->max_speed_hz >= speed) {
809 			spi->max_speed_hz = speed;
810 		} else {
811 			dev_err(&spi->dev, "Can't set %dHz transfer speed\n",
812 				spi->max_speed_hz);
813 			err = -EINVAL;
814 			goto setup_exit;
815 		}
816 	}
817 
818 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
819 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
820 	s3c64xx_spi_set_cs(spi, false);
821 
822 	return 0;
823 
824 setup_exit:
825 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
826 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
827 	/* setup() returns with device de-selected */
828 	s3c64xx_spi_set_cs(spi, false);
829 
830 	if (gpio_is_valid(spi->cs_gpio))
831 		gpio_free(spi->cs_gpio);
832 	spi_set_ctldata(spi, NULL);
833 
834 err_gpio_req:
835 	if (spi->dev.of_node)
836 		kfree(cs);
837 
838 	return err;
839 }
840 
841 static void s3c64xx_spi_cleanup(struct spi_device *spi)
842 {
843 	struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
844 
845 	if (gpio_is_valid(spi->cs_gpio)) {
846 		gpio_free(spi->cs_gpio);
847 		if (spi->dev.of_node)
848 			kfree(cs);
849 		else {
850 			/* On non-DT platforms, the SPI core sets
851 			 * spi->cs_gpio to -ENOENT and .setup()
852 			 * overrides it with the GPIO pin value
853 			 * passed using platform data.
854 			 */
855 			spi->cs_gpio = -ENOENT;
856 		}
857 	}
858 
859 	spi_set_ctldata(spi, NULL);
860 }
861 
862 static irqreturn_t s3c64xx_spi_irq(int irq, void *data)
863 {
864 	struct s3c64xx_spi_driver_data *sdd = data;
865 	struct spi_master *spi = sdd->master;
866 	unsigned int val, clr = 0;
867 
868 	val = readl(sdd->regs + S3C64XX_SPI_STATUS);
869 
870 	if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) {
871 		clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR;
872 		dev_err(&spi->dev, "RX overrun\n");
873 	}
874 	if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) {
875 		clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR;
876 		dev_err(&spi->dev, "RX underrun\n");
877 	}
878 	if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) {
879 		clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR;
880 		dev_err(&spi->dev, "TX overrun\n");
881 	}
882 	if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) {
883 		clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
884 		dev_err(&spi->dev, "TX underrun\n");
885 	}
886 
887 	/* Clear the pending irq by setting and then clearing it */
888 	writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR);
889 	writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR);
890 
891 	return IRQ_HANDLED;
892 }
893 
894 static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel)
895 {
896 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
897 	void __iomem *regs = sdd->regs;
898 	unsigned int val;
899 
900 	sdd->cur_speed = 0;
901 
902 	if (sci->no_cs)
903 		writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
904 	else if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
905 		writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
906 
907 	/* Disable Interrupts - we use Polling if not DMA mode */
908 	writel(0, regs + S3C64XX_SPI_INT_EN);
909 
910 	if (!sdd->port_conf->clk_from_cmu)
911 		writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
912 				regs + S3C64XX_SPI_CLK_CFG);
913 	writel(0, regs + S3C64XX_SPI_MODE_CFG);
914 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
915 
916 	/* Clear any irq pending bits, should set and clear the bits */
917 	val = S3C64XX_SPI_PND_RX_OVERRUN_CLR |
918 		S3C64XX_SPI_PND_RX_UNDERRUN_CLR |
919 		S3C64XX_SPI_PND_TX_OVERRUN_CLR |
920 		S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
921 	writel(val, regs + S3C64XX_SPI_PENDING_CLR);
922 	writel(0, regs + S3C64XX_SPI_PENDING_CLR);
923 
924 	writel(0, regs + S3C64XX_SPI_SWAP_CFG);
925 
926 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
927 	val &= ~S3C64XX_SPI_MODE_4BURST;
928 	val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
929 	val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
930 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
931 
932 	flush_fifo(sdd);
933 }
934 
935 #ifdef CONFIG_OF
936 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
937 {
938 	struct s3c64xx_spi_info *sci;
939 	u32 temp;
940 
941 	sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
942 	if (!sci)
943 		return ERR_PTR(-ENOMEM);
944 
945 	if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
946 		dev_warn(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
947 		sci->src_clk_nr = 0;
948 	} else {
949 		sci->src_clk_nr = temp;
950 	}
951 
952 	if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
953 		dev_warn(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
954 		sci->num_cs = 1;
955 	} else {
956 		sci->num_cs = temp;
957 	}
958 
959 	sci->no_cs = of_property_read_bool(dev->of_node, "no-cs-readback");
960 
961 	return sci;
962 }
963 #else
964 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
965 {
966 	return dev_get_platdata(dev);
967 }
968 #endif
969 
970 static const struct of_device_id s3c64xx_spi_dt_match[];
971 
972 static inline struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
973 						struct platform_device *pdev)
974 {
975 #ifdef CONFIG_OF
976 	if (pdev->dev.of_node) {
977 		const struct of_device_id *match;
978 		match = of_match_node(s3c64xx_spi_dt_match, pdev->dev.of_node);
979 		return (struct s3c64xx_spi_port_config *)match->data;
980 	}
981 #endif
982 	return (struct s3c64xx_spi_port_config *)
983 			 platform_get_device_id(pdev)->driver_data;
984 }
985 
986 static int s3c64xx_spi_probe(struct platform_device *pdev)
987 {
988 	struct resource	*mem_res;
989 	struct s3c64xx_spi_driver_data *sdd;
990 	struct s3c64xx_spi_info *sci = dev_get_platdata(&pdev->dev);
991 	struct spi_master *master;
992 	int ret, irq;
993 	char clk_name[16];
994 
995 	if (!sci && pdev->dev.of_node) {
996 		sci = s3c64xx_spi_parse_dt(&pdev->dev);
997 		if (IS_ERR(sci))
998 			return PTR_ERR(sci);
999 	}
1000 
1001 	if (!sci) {
1002 		dev_err(&pdev->dev, "platform_data missing!\n");
1003 		return -ENODEV;
1004 	}
1005 
1006 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1007 	if (mem_res == NULL) {
1008 		dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
1009 		return -ENXIO;
1010 	}
1011 
1012 	irq = platform_get_irq(pdev, 0);
1013 	if (irq < 0) {
1014 		dev_warn(&pdev->dev, "Failed to get IRQ: %d\n", irq);
1015 		return irq;
1016 	}
1017 
1018 	master = spi_alloc_master(&pdev->dev,
1019 				sizeof(struct s3c64xx_spi_driver_data));
1020 	if (master == NULL) {
1021 		dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
1022 		return -ENOMEM;
1023 	}
1024 
1025 	platform_set_drvdata(pdev, master);
1026 
1027 	sdd = spi_master_get_devdata(master);
1028 	sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
1029 	sdd->master = master;
1030 	sdd->cntrlr_info = sci;
1031 	sdd->pdev = pdev;
1032 	sdd->sfr_start = mem_res->start;
1033 	if (pdev->dev.of_node) {
1034 		ret = of_alias_get_id(pdev->dev.of_node, "spi");
1035 		if (ret < 0) {
1036 			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
1037 				ret);
1038 			goto err_deref_master;
1039 		}
1040 		sdd->port_id = ret;
1041 	} else {
1042 		sdd->port_id = pdev->id;
1043 	}
1044 
1045 	sdd->cur_bpw = 8;
1046 
1047 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
1048 	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
1049 
1050 	master->dev.of_node = pdev->dev.of_node;
1051 	master->bus_num = sdd->port_id;
1052 	master->setup = s3c64xx_spi_setup;
1053 	master->cleanup = s3c64xx_spi_cleanup;
1054 	master->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
1055 	master->prepare_message = s3c64xx_spi_prepare_message;
1056 	master->transfer_one = s3c64xx_spi_transfer_one;
1057 	master->num_chipselect = sci->num_cs;
1058 	master->dma_alignment = 8;
1059 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
1060 					SPI_BPW_MASK(8);
1061 	/* the spi->mode bits understood by this driver: */
1062 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1063 	master->auto_runtime_pm = true;
1064 	if (!is_polling(sdd))
1065 		master->can_dma = s3c64xx_spi_can_dma;
1066 
1067 	sdd->regs = devm_ioremap_resource(&pdev->dev, mem_res);
1068 	if (IS_ERR(sdd->regs)) {
1069 		ret = PTR_ERR(sdd->regs);
1070 		goto err_deref_master;
1071 	}
1072 
1073 	if (sci->cfg_gpio && sci->cfg_gpio()) {
1074 		dev_err(&pdev->dev, "Unable to config gpio\n");
1075 		ret = -EBUSY;
1076 		goto err_deref_master;
1077 	}
1078 
1079 	/* Setup clocks */
1080 	sdd->clk = devm_clk_get(&pdev->dev, "spi");
1081 	if (IS_ERR(sdd->clk)) {
1082 		dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
1083 		ret = PTR_ERR(sdd->clk);
1084 		goto err_deref_master;
1085 	}
1086 
1087 	ret = clk_prepare_enable(sdd->clk);
1088 	if (ret) {
1089 		dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
1090 		goto err_deref_master;
1091 	}
1092 
1093 	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
1094 	sdd->src_clk = devm_clk_get(&pdev->dev, clk_name);
1095 	if (IS_ERR(sdd->src_clk)) {
1096 		dev_err(&pdev->dev,
1097 			"Unable to acquire clock '%s'\n", clk_name);
1098 		ret = PTR_ERR(sdd->src_clk);
1099 		goto err_disable_clk;
1100 	}
1101 
1102 	ret = clk_prepare_enable(sdd->src_clk);
1103 	if (ret) {
1104 		dev_err(&pdev->dev, "Couldn't enable clock '%s'\n", clk_name);
1105 		goto err_disable_clk;
1106 	}
1107 
1108 	if (sdd->port_conf->clk_ioclk) {
1109 		sdd->ioclk = devm_clk_get(&pdev->dev, "spi_ioclk");
1110 		if (IS_ERR(sdd->ioclk)) {
1111 			dev_err(&pdev->dev, "Unable to acquire 'ioclk'\n");
1112 			ret = PTR_ERR(sdd->ioclk);
1113 			goto err_disable_src_clk;
1114 		}
1115 
1116 		ret = clk_prepare_enable(sdd->ioclk);
1117 		if (ret) {
1118 			dev_err(&pdev->dev, "Couldn't enable clock 'ioclk'\n");
1119 			goto err_disable_src_clk;
1120 		}
1121 	}
1122 
1123 	if (!is_polling(sdd)) {
1124 		/* Acquire DMA channels */
1125 		sdd->rx_dma.ch = dma_request_slave_channel_reason(&pdev->dev,
1126 								  "rx");
1127 		if (IS_ERR(sdd->rx_dma.ch)) {
1128 			dev_err(&pdev->dev, "Failed to get RX DMA channel\n");
1129 			ret = PTR_ERR(sdd->rx_dma.ch);
1130 			goto err_disable_io_clk;
1131 		}
1132 		sdd->tx_dma.ch = dma_request_slave_channel_reason(&pdev->dev,
1133 								  "tx");
1134 		if (IS_ERR(sdd->tx_dma.ch)) {
1135 			dev_err(&pdev->dev, "Failed to get TX DMA channel\n");
1136 			ret = PTR_ERR(sdd->tx_dma.ch);
1137 			goto err_release_rx_dma;
1138 		}
1139 	}
1140 
1141 	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1142 	pm_runtime_use_autosuspend(&pdev->dev);
1143 	pm_runtime_set_active(&pdev->dev);
1144 	pm_runtime_enable(&pdev->dev);
1145 	pm_runtime_get_sync(&pdev->dev);
1146 
1147 	/* Setup Deufult Mode */
1148 	s3c64xx_spi_hwinit(sdd, sdd->port_id);
1149 
1150 	spin_lock_init(&sdd->lock);
1151 	init_completion(&sdd->xfer_completion);
1152 
1153 	ret = devm_request_irq(&pdev->dev, irq, s3c64xx_spi_irq, 0,
1154 				"spi-s3c64xx", sdd);
1155 	if (ret != 0) {
1156 		dev_err(&pdev->dev, "Failed to request IRQ %d: %d\n",
1157 			irq, ret);
1158 		goto err_pm_put;
1159 	}
1160 
1161 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1162 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1163 	       sdd->regs + S3C64XX_SPI_INT_EN);
1164 
1165 	ret = devm_spi_register_master(&pdev->dev, master);
1166 	if (ret != 0) {
1167 		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
1168 		goto err_pm_put;
1169 	}
1170 
1171 	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",
1172 					sdd->port_id, master->num_chipselect);
1173 	dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\n",
1174 					mem_res, (FIFO_LVL_MASK(sdd) >> 1) + 1);
1175 
1176 	pm_runtime_mark_last_busy(&pdev->dev);
1177 	pm_runtime_put_autosuspend(&pdev->dev);
1178 
1179 	return 0;
1180 
1181 err_pm_put:
1182 	pm_runtime_put_noidle(&pdev->dev);
1183 	pm_runtime_disable(&pdev->dev);
1184 	pm_runtime_set_suspended(&pdev->dev);
1185 
1186 	if (!is_polling(sdd))
1187 		dma_release_channel(sdd->tx_dma.ch);
1188 err_release_rx_dma:
1189 	if (!is_polling(sdd))
1190 		dma_release_channel(sdd->rx_dma.ch);
1191 err_disable_io_clk:
1192 	clk_disable_unprepare(sdd->ioclk);
1193 err_disable_src_clk:
1194 	clk_disable_unprepare(sdd->src_clk);
1195 err_disable_clk:
1196 	clk_disable_unprepare(sdd->clk);
1197 err_deref_master:
1198 	spi_master_put(master);
1199 
1200 	return ret;
1201 }
1202 
1203 static int s3c64xx_spi_remove(struct platform_device *pdev)
1204 {
1205 	struct spi_master *master = platform_get_drvdata(pdev);
1206 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1207 
1208 	pm_runtime_get_sync(&pdev->dev);
1209 
1210 	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
1211 
1212 	if (!is_polling(sdd)) {
1213 		dma_release_channel(sdd->rx_dma.ch);
1214 		dma_release_channel(sdd->tx_dma.ch);
1215 	}
1216 
1217 	clk_disable_unprepare(sdd->ioclk);
1218 
1219 	clk_disable_unprepare(sdd->src_clk);
1220 
1221 	clk_disable_unprepare(sdd->clk);
1222 
1223 	pm_runtime_put_noidle(&pdev->dev);
1224 	pm_runtime_disable(&pdev->dev);
1225 	pm_runtime_set_suspended(&pdev->dev);
1226 
1227 	return 0;
1228 }
1229 
1230 #ifdef CONFIG_PM_SLEEP
1231 static int s3c64xx_spi_suspend(struct device *dev)
1232 {
1233 	struct spi_master *master = dev_get_drvdata(dev);
1234 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1235 
1236 	int ret = spi_master_suspend(master);
1237 	if (ret)
1238 		return ret;
1239 
1240 	ret = pm_runtime_force_suspend(dev);
1241 	if (ret < 0)
1242 		return ret;
1243 
1244 	sdd->cur_speed = 0; /* Output Clock is stopped */
1245 
1246 	return 0;
1247 }
1248 
1249 static int s3c64xx_spi_resume(struct device *dev)
1250 {
1251 	struct spi_master *master = dev_get_drvdata(dev);
1252 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1253 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1254 	int ret;
1255 
1256 	if (sci->cfg_gpio)
1257 		sci->cfg_gpio();
1258 
1259 	ret = pm_runtime_force_resume(dev);
1260 	if (ret < 0)
1261 		return ret;
1262 
1263 	s3c64xx_spi_hwinit(sdd, sdd->port_id);
1264 
1265 	return spi_master_resume(master);
1266 }
1267 #endif /* CONFIG_PM_SLEEP */
1268 
1269 #ifdef CONFIG_PM
1270 static int s3c64xx_spi_runtime_suspend(struct device *dev)
1271 {
1272 	struct spi_master *master = dev_get_drvdata(dev);
1273 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1274 
1275 	clk_disable_unprepare(sdd->clk);
1276 	clk_disable_unprepare(sdd->src_clk);
1277 	clk_disable_unprepare(sdd->ioclk);
1278 
1279 	return 0;
1280 }
1281 
1282 static int s3c64xx_spi_runtime_resume(struct device *dev)
1283 {
1284 	struct spi_master *master = dev_get_drvdata(dev);
1285 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1286 	int ret;
1287 
1288 	if (sdd->port_conf->clk_ioclk) {
1289 		ret = clk_prepare_enable(sdd->ioclk);
1290 		if (ret != 0)
1291 			return ret;
1292 	}
1293 
1294 	ret = clk_prepare_enable(sdd->src_clk);
1295 	if (ret != 0)
1296 		goto err_disable_ioclk;
1297 
1298 	ret = clk_prepare_enable(sdd->clk);
1299 	if (ret != 0)
1300 		goto err_disable_src_clk;
1301 
1302 	return 0;
1303 
1304 err_disable_src_clk:
1305 	clk_disable_unprepare(sdd->src_clk);
1306 err_disable_ioclk:
1307 	clk_disable_unprepare(sdd->ioclk);
1308 
1309 	return ret;
1310 }
1311 #endif /* CONFIG_PM */
1312 
1313 static const struct dev_pm_ops s3c64xx_spi_pm = {
1314 	SET_SYSTEM_SLEEP_PM_OPS(s3c64xx_spi_suspend, s3c64xx_spi_resume)
1315 	SET_RUNTIME_PM_OPS(s3c64xx_spi_runtime_suspend,
1316 			   s3c64xx_spi_runtime_resume, NULL)
1317 };
1318 
1319 static struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
1320 	.fifo_lvl_mask	= { 0x7f },
1321 	.rx_lvl_offset	= 13,
1322 	.tx_st_done	= 21,
1323 	.high_speed	= true,
1324 };
1325 
1326 static struct s3c64xx_spi_port_config s3c6410_spi_port_config = {
1327 	.fifo_lvl_mask	= { 0x7f, 0x7F },
1328 	.rx_lvl_offset	= 13,
1329 	.tx_st_done	= 21,
1330 };
1331 
1332 static struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
1333 	.fifo_lvl_mask	= { 0x1ff, 0x7F },
1334 	.rx_lvl_offset	= 15,
1335 	.tx_st_done	= 25,
1336 	.high_speed	= true,
1337 };
1338 
1339 static struct s3c64xx_spi_port_config exynos4_spi_port_config = {
1340 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F },
1341 	.rx_lvl_offset	= 15,
1342 	.tx_st_done	= 25,
1343 	.high_speed	= true,
1344 	.clk_from_cmu	= true,
1345 };
1346 
1347 static struct s3c64xx_spi_port_config exynos5440_spi_port_config = {
1348 	.fifo_lvl_mask	= { 0x1ff },
1349 	.rx_lvl_offset	= 15,
1350 	.tx_st_done	= 25,
1351 	.high_speed	= true,
1352 	.clk_from_cmu	= true,
1353 	.quirks		= S3C64XX_SPI_QUIRK_POLL,
1354 };
1355 
1356 static struct s3c64xx_spi_port_config exynos7_spi_port_config = {
1357 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},
1358 	.rx_lvl_offset	= 15,
1359 	.tx_st_done	= 25,
1360 	.high_speed	= true,
1361 	.clk_from_cmu	= true,
1362 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1363 };
1364 
1365 static struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
1366 	.fifo_lvl_mask	= { 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff},
1367 	.rx_lvl_offset	= 15,
1368 	.tx_st_done	= 25,
1369 	.high_speed	= true,
1370 	.clk_from_cmu	= true,
1371 	.clk_ioclk	= true,
1372 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1373 };
1374 
1375 static const struct platform_device_id s3c64xx_spi_driver_ids[] = {
1376 	{
1377 		.name		= "s3c2443-spi",
1378 		.driver_data	= (kernel_ulong_t)&s3c2443_spi_port_config,
1379 	}, {
1380 		.name		= "s3c6410-spi",
1381 		.driver_data	= (kernel_ulong_t)&s3c6410_spi_port_config,
1382 	},
1383 	{ },
1384 };
1385 
1386 static const struct of_device_id s3c64xx_spi_dt_match[] = {
1387 	{ .compatible = "samsung,s3c2443-spi",
1388 			.data = (void *)&s3c2443_spi_port_config,
1389 	},
1390 	{ .compatible = "samsung,s3c6410-spi",
1391 			.data = (void *)&s3c6410_spi_port_config,
1392 	},
1393 	{ .compatible = "samsung,s5pv210-spi",
1394 			.data = (void *)&s5pv210_spi_port_config,
1395 	},
1396 	{ .compatible = "samsung,exynos4210-spi",
1397 			.data = (void *)&exynos4_spi_port_config,
1398 	},
1399 	{ .compatible = "samsung,exynos5440-spi",
1400 			.data = (void *)&exynos5440_spi_port_config,
1401 	},
1402 	{ .compatible = "samsung,exynos7-spi",
1403 			.data = (void *)&exynos7_spi_port_config,
1404 	},
1405 	{ .compatible = "samsung,exynos5433-spi",
1406 			.data = (void *)&exynos5433_spi_port_config,
1407 	},
1408 	{ },
1409 };
1410 MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
1411 
1412 static struct platform_driver s3c64xx_spi_driver = {
1413 	.driver = {
1414 		.name	= "s3c64xx-spi",
1415 		.pm = &s3c64xx_spi_pm,
1416 		.of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
1417 	},
1418 	.probe = s3c64xx_spi_probe,
1419 	.remove = s3c64xx_spi_remove,
1420 	.id_table = s3c64xx_spi_driver_ids,
1421 };
1422 MODULE_ALIAS("platform:s3c64xx-spi");
1423 
1424 module_platform_driver(s3c64xx_spi_driver);
1425 
1426 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1427 MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1428 MODULE_LICENSE("GPL");
1429