xref: /openbmc/linux/drivers/spi/spi-s3c64xx.c (revision 842ed298)
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_CS_REG		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_CS_NSC_CNT_2		(2<<4)
68 #define S3C64XX_SPI_CS_AUTO			(1<<1)
69 #define S3C64XX_SPI_CS_SIG_INACT		(1<<0)
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 	dma_cookie_t cookie;
126 	enum dma_transfer_direction direction;
127 };
128 
129 /**
130  * struct s3c64xx_spi_info - SPI Controller hardware info
131  * @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
132  * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
133  * @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
134  * @quirks: Bitmask of known quirks
135  * @high_speed: True, if the controller supports HIGH_SPEED_EN bit.
136  * @clk_from_cmu: True, if the controller does not include a clock mux and
137  *	prescaler unit.
138  * @clk_ioclk: True if clock is present on this device
139  *
140  * The Samsung s3c64xx SPI controller are used on various Samsung SoC's but
141  * differ in some aspects such as the size of the fifo and spi bus clock
142  * setup. Such differences are specified to the driver using this structure
143  * which is provided as driver data to the driver.
144  */
145 struct s3c64xx_spi_port_config {
146 	int	fifo_lvl_mask[MAX_SPI_PORTS];
147 	int	rx_lvl_offset;
148 	int	tx_st_done;
149 	int	quirks;
150 	bool	high_speed;
151 	bool	clk_from_cmu;
152 	bool	clk_ioclk;
153 };
154 
155 /**
156  * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
157  * @clk: Pointer to the spi clock.
158  * @src_clk: Pointer to the clock used to generate SPI signals.
159  * @ioclk: Pointer to the i/o clock between master and slave
160  * @pdev: Pointer to device's platform device data
161  * @master: Pointer to the SPI Protocol master.
162  * @cntrlr_info: Platform specific data for the controller this driver manages.
163  * @lock: Controller specific lock.
164  * @state: Set of FLAGS to indicate status.
165  * @sfr_start: BUS address of SPI controller regs.
166  * @regs: Pointer to ioremap'ed controller registers.
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: Current clock speed
171  * @rx_dma: Local receive DMA data (e.g. chan and direction)
172  * @tx_dma: Local transmit DMA data (e.g. chan and direction)
173  * @port_conf: Local SPI port configuartion data
174  * @port_id: Port identification number
175  */
176 struct s3c64xx_spi_driver_data {
177 	void __iomem                    *regs;
178 	struct clk                      *clk;
179 	struct clk                      *src_clk;
180 	struct clk                      *ioclk;
181 	struct platform_device          *pdev;
182 	struct spi_master               *master;
183 	struct s3c64xx_spi_info         *cntrlr_info;
184 	spinlock_t                      lock;
185 	unsigned long                   sfr_start;
186 	struct completion               xfer_completion;
187 	unsigned                        state;
188 	unsigned                        cur_mode, cur_bpw;
189 	unsigned                        cur_speed;
190 	struct s3c64xx_spi_dma_data	rx_dma;
191 	struct s3c64xx_spi_dma_data	tx_dma;
192 	struct s3c64xx_spi_port_config	*port_conf;
193 	unsigned int			port_id;
194 };
195 
196 static void s3c64xx_flush_fifo(struct s3c64xx_spi_driver_data *sdd)
197 {
198 	void __iomem *regs = sdd->regs;
199 	unsigned long loops;
200 	u32 val;
201 
202 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
203 
204 	val = readl(regs + S3C64XX_SPI_CH_CFG);
205 	val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON);
206 	writel(val, regs + S3C64XX_SPI_CH_CFG);
207 
208 	val = readl(regs + S3C64XX_SPI_CH_CFG);
209 	val |= S3C64XX_SPI_CH_SW_RST;
210 	val &= ~S3C64XX_SPI_CH_HS_EN;
211 	writel(val, regs + S3C64XX_SPI_CH_CFG);
212 
213 	/* Flush TxFIFO*/
214 	loops = msecs_to_loops(1);
215 	do {
216 		val = readl(regs + S3C64XX_SPI_STATUS);
217 	} while (TX_FIFO_LVL(val, sdd) && loops--);
218 
219 	if (loops == 0)
220 		dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n");
221 
222 	/* Flush RxFIFO*/
223 	loops = msecs_to_loops(1);
224 	do {
225 		val = readl(regs + S3C64XX_SPI_STATUS);
226 		if (RX_FIFO_LVL(val, sdd))
227 			readl(regs + S3C64XX_SPI_RX_DATA);
228 		else
229 			break;
230 	} while (loops--);
231 
232 	if (loops == 0)
233 		dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n");
234 
235 	val = readl(regs + S3C64XX_SPI_CH_CFG);
236 	val &= ~S3C64XX_SPI_CH_SW_RST;
237 	writel(val, regs + S3C64XX_SPI_CH_CFG);
238 
239 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
240 	val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
241 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
242 }
243 
244 static void s3c64xx_spi_dmacb(void *data)
245 {
246 	struct s3c64xx_spi_driver_data *sdd;
247 	struct s3c64xx_spi_dma_data *dma = data;
248 	unsigned long flags;
249 
250 	if (dma->direction == DMA_DEV_TO_MEM)
251 		sdd = container_of(data,
252 			struct s3c64xx_spi_driver_data, rx_dma);
253 	else
254 		sdd = container_of(data,
255 			struct s3c64xx_spi_driver_data, tx_dma);
256 
257 	spin_lock_irqsave(&sdd->lock, flags);
258 
259 	if (dma->direction == DMA_DEV_TO_MEM) {
260 		sdd->state &= ~RXBUSY;
261 		if (!(sdd->state & TXBUSY))
262 			complete(&sdd->xfer_completion);
263 	} else {
264 		sdd->state &= ~TXBUSY;
265 		if (!(sdd->state & RXBUSY))
266 			complete(&sdd->xfer_completion);
267 	}
268 
269 	spin_unlock_irqrestore(&sdd->lock, flags);
270 }
271 
272 static int prepare_dma(struct s3c64xx_spi_dma_data *dma,
273 			struct sg_table *sgt)
274 {
275 	struct s3c64xx_spi_driver_data *sdd;
276 	struct dma_slave_config config;
277 	struct dma_async_tx_descriptor *desc;
278 	int ret;
279 
280 	memset(&config, 0, sizeof(config));
281 
282 	if (dma->direction == DMA_DEV_TO_MEM) {
283 		sdd = container_of((void *)dma,
284 			struct s3c64xx_spi_driver_data, rx_dma);
285 		config.direction = dma->direction;
286 		config.src_addr = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
287 		config.src_addr_width = sdd->cur_bpw / 8;
288 		config.src_maxburst = 1;
289 		dmaengine_slave_config(dma->ch, &config);
290 	} else {
291 		sdd = container_of((void *)dma,
292 			struct s3c64xx_spi_driver_data, tx_dma);
293 		config.direction = dma->direction;
294 		config.dst_addr = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
295 		config.dst_addr_width = sdd->cur_bpw / 8;
296 		config.dst_maxburst = 1;
297 		dmaengine_slave_config(dma->ch, &config);
298 	}
299 
300 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
301 				       dma->direction, DMA_PREP_INTERRUPT);
302 	if (!desc) {
303 		dev_err(&sdd->pdev->dev, "unable to prepare %s scatterlist",
304 			dma->direction == DMA_DEV_TO_MEM ? "rx" : "tx");
305 		return -ENOMEM;
306 	}
307 
308 	desc->callback = s3c64xx_spi_dmacb;
309 	desc->callback_param = dma;
310 
311 	dma->cookie = dmaengine_submit(desc);
312 	ret = dma_submit_error(dma->cookie);
313 	if (ret) {
314 		dev_err(&sdd->pdev->dev, "DMA submission failed");
315 		return -EIO;
316 	}
317 
318 	dma_async_issue_pending(dma->ch);
319 	return 0;
320 }
321 
322 static void s3c64xx_spi_set_cs(struct spi_device *spi, bool enable)
323 {
324 	struct s3c64xx_spi_driver_data *sdd =
325 					spi_master_get_devdata(spi->master);
326 
327 	if (sdd->cntrlr_info->no_cs)
328 		return;
329 
330 	if (enable) {
331 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO)) {
332 			writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
333 		} else {
334 			u32 ssel = readl(sdd->regs + S3C64XX_SPI_CS_REG);
335 
336 			ssel |= (S3C64XX_SPI_CS_AUTO |
337 						S3C64XX_SPI_CS_NSC_CNT_2);
338 			writel(ssel, sdd->regs + S3C64XX_SPI_CS_REG);
339 		}
340 	} else {
341 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
342 			writel(S3C64XX_SPI_CS_SIG_INACT,
343 			       sdd->regs + S3C64XX_SPI_CS_REG);
344 	}
345 }
346 
347 static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
348 {
349 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
350 
351 	if (is_polling(sdd))
352 		return 0;
353 
354 	spi->dma_rx = sdd->rx_dma.ch;
355 	spi->dma_tx = sdd->tx_dma.ch;
356 
357 	return 0;
358 }
359 
360 static bool s3c64xx_spi_can_dma(struct spi_master *master,
361 				struct spi_device *spi,
362 				struct spi_transfer *xfer)
363 {
364 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
365 
366 	return xfer->len > (FIFO_LVL_MASK(sdd) >> 1) + 1;
367 }
368 
369 static int s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
370 				    struct spi_transfer *xfer, int dma_mode)
371 {
372 	void __iomem *regs = sdd->regs;
373 	u32 modecfg, chcfg;
374 	int ret = 0;
375 
376 	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
377 	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
378 
379 	chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
380 	chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
381 
382 	if (dma_mode) {
383 		chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
384 	} else {
385 		/* Always shift in data in FIFO, even if xfer is Tx only,
386 		 * this helps setting PCKT_CNT value for generating clocks
387 		 * as exactly needed.
388 		 */
389 		chcfg |= S3C64XX_SPI_CH_RXCH_ON;
390 		writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
391 					| S3C64XX_SPI_PACKET_CNT_EN,
392 					regs + S3C64XX_SPI_PACKET_CNT);
393 	}
394 
395 	if (xfer->tx_buf != NULL) {
396 		sdd->state |= TXBUSY;
397 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
398 		if (dma_mode) {
399 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
400 			ret = prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
401 		} else {
402 			switch (sdd->cur_bpw) {
403 			case 32:
404 				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
405 					xfer->tx_buf, xfer->len / 4);
406 				break;
407 			case 16:
408 				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
409 					xfer->tx_buf, xfer->len / 2);
410 				break;
411 			default:
412 				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
413 					xfer->tx_buf, xfer->len);
414 				break;
415 			}
416 		}
417 	}
418 
419 	if (xfer->rx_buf != NULL) {
420 		sdd->state |= RXBUSY;
421 
422 		if (sdd->port_conf->high_speed && sdd->cur_speed >= 30000000UL
423 					&& !(sdd->cur_mode & SPI_CPHA))
424 			chcfg |= S3C64XX_SPI_CH_HS_EN;
425 
426 		if (dma_mode) {
427 			modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
428 			chcfg |= S3C64XX_SPI_CH_RXCH_ON;
429 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
430 					| S3C64XX_SPI_PACKET_CNT_EN,
431 					regs + S3C64XX_SPI_PACKET_CNT);
432 			ret = prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
433 		}
434 	}
435 
436 	if (ret)
437 		return ret;
438 
439 	writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
440 	writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
441 
442 	return 0;
443 }
444 
445 static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
446 					int timeout_ms)
447 {
448 	void __iomem *regs = sdd->regs;
449 	unsigned long val = 1;
450 	u32 status;
451 
452 	/* max fifo depth available */
453 	u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
454 
455 	if (timeout_ms)
456 		val = msecs_to_loops(timeout_ms);
457 
458 	do {
459 		status = readl(regs + S3C64XX_SPI_STATUS);
460 	} while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
461 
462 	/* return the actual received data length */
463 	return RX_FIFO_LVL(status, sdd);
464 }
465 
466 static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
467 				struct spi_transfer *xfer)
468 {
469 	void __iomem *regs = sdd->regs;
470 	unsigned long val;
471 	u32 status;
472 	int ms;
473 
474 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
475 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
476 	ms += 30;               /* some tolerance */
477 	ms = max(ms, 100);      /* minimum timeout */
478 
479 	val = msecs_to_jiffies(ms) + 10;
480 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
481 
482 	/*
483 	 * If the previous xfer was completed within timeout, then
484 	 * proceed further else return -EIO.
485 	 * DmaTx returns after simply writing data in the FIFO,
486 	 * w/o waiting for real transmission on the bus to finish.
487 	 * DmaRx returns only after Dma read data from FIFO which
488 	 * needs bus transmission to finish, so we don't worry if
489 	 * Xfer involved Rx(with or without Tx).
490 	 */
491 	if (val && !xfer->rx_buf) {
492 		val = msecs_to_loops(10);
493 		status = readl(regs + S3C64XX_SPI_STATUS);
494 		while ((TX_FIFO_LVL(status, sdd)
495 			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
496 		       && --val) {
497 			cpu_relax();
498 			status = readl(regs + S3C64XX_SPI_STATUS);
499 		}
500 
501 	}
502 
503 	/* If timed out while checking rx/tx status return error */
504 	if (!val)
505 		return -EIO;
506 
507 	return 0;
508 }
509 
510 static int s3c64xx_wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
511 				struct spi_transfer *xfer)
512 {
513 	void __iomem *regs = sdd->regs;
514 	unsigned long val;
515 	u32 status;
516 	int loops;
517 	u32 cpy_len;
518 	u8 *buf;
519 	int ms;
520 
521 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
522 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
523 	ms += 10; /* some tolerance */
524 
525 	val = msecs_to_loops(ms);
526 	do {
527 		status = readl(regs + S3C64XX_SPI_STATUS);
528 	} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
529 
530 	if (!val)
531 		return -EIO;
532 
533 	/* If it was only Tx */
534 	if (!xfer->rx_buf) {
535 		sdd->state &= ~TXBUSY;
536 		return 0;
537 	}
538 
539 	/*
540 	 * If the receive length is bigger than the controller fifo
541 	 * size, calculate the loops and read the fifo as many times.
542 	 * loops = length / max fifo size (calculated by using the
543 	 * fifo mask).
544 	 * For any size less than the fifo size the below code is
545 	 * executed atleast once.
546 	 */
547 	loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
548 	buf = xfer->rx_buf;
549 	do {
550 		/* wait for data to be received in the fifo */
551 		cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
552 						       (loops ? ms : 0));
553 
554 		switch (sdd->cur_bpw) {
555 		case 32:
556 			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
557 				     buf, cpy_len / 4);
558 			break;
559 		case 16:
560 			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
561 				     buf, cpy_len / 2);
562 			break;
563 		default:
564 			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
565 				    buf, cpy_len);
566 			break;
567 		}
568 
569 		buf = buf + cpy_len;
570 	} while (loops--);
571 	sdd->state &= ~RXBUSY;
572 
573 	return 0;
574 }
575 
576 static int s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
577 {
578 	void __iomem *regs = sdd->regs;
579 	int ret;
580 	u32 val;
581 
582 	/* Disable Clock */
583 	if (!sdd->port_conf->clk_from_cmu) {
584 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
585 		val &= ~S3C64XX_SPI_ENCLK_ENABLE;
586 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
587 	}
588 
589 	/* Set Polarity and Phase */
590 	val = readl(regs + S3C64XX_SPI_CH_CFG);
591 	val &= ~(S3C64XX_SPI_CH_SLAVE |
592 			S3C64XX_SPI_CPOL_L |
593 			S3C64XX_SPI_CPHA_B);
594 
595 	if (sdd->cur_mode & SPI_CPOL)
596 		val |= S3C64XX_SPI_CPOL_L;
597 
598 	if (sdd->cur_mode & SPI_CPHA)
599 		val |= S3C64XX_SPI_CPHA_B;
600 
601 	writel(val, regs + S3C64XX_SPI_CH_CFG);
602 
603 	/* Set Channel & DMA Mode */
604 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
605 	val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
606 			| S3C64XX_SPI_MODE_CH_TSZ_MASK);
607 
608 	switch (sdd->cur_bpw) {
609 	case 32:
610 		val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
611 		val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;
612 		break;
613 	case 16:
614 		val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
615 		val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;
616 		break;
617 	default:
618 		val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
619 		val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;
620 		break;
621 	}
622 
623 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
624 
625 	if (sdd->port_conf->clk_from_cmu) {
626 		/* The src_clk clock is divided internally by 2 */
627 		ret = clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
628 		if (ret)
629 			return ret;
630 		sdd->cur_speed = clk_get_rate(sdd->src_clk) / 2;
631 	} else {
632 		/* Configure Clock */
633 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
634 		val &= ~S3C64XX_SPI_PSR_MASK;
635 		val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1)
636 				& S3C64XX_SPI_PSR_MASK);
637 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
638 
639 		/* Enable Clock */
640 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
641 		val |= S3C64XX_SPI_ENCLK_ENABLE;
642 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
643 	}
644 
645 	return 0;
646 }
647 
648 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
649 
650 static int s3c64xx_spi_prepare_message(struct spi_master *master,
651 				       struct spi_message *msg)
652 {
653 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
654 	struct spi_device *spi = msg->spi;
655 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
656 
657 	/* Configure feedback delay */
658 	writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
659 
660 	return 0;
661 }
662 
663 static int s3c64xx_spi_transfer_one(struct spi_master *master,
664 				    struct spi_device *spi,
665 				    struct spi_transfer *xfer)
666 {
667 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
668 	const unsigned int fifo_len = (FIFO_LVL_MASK(sdd) >> 1) + 1;
669 	const void *tx_buf = NULL;
670 	void *rx_buf = NULL;
671 	int target_len = 0, origin_len = 0;
672 	int use_dma = 0;
673 	int status;
674 	u32 speed;
675 	u8 bpw;
676 	unsigned long flags;
677 
678 	reinit_completion(&sdd->xfer_completion);
679 
680 	/* Only BPW and Speed may change across transfers */
681 	bpw = xfer->bits_per_word;
682 	speed = xfer->speed_hz;
683 
684 	if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
685 		sdd->cur_bpw = bpw;
686 		sdd->cur_speed = speed;
687 		sdd->cur_mode = spi->mode;
688 		status = s3c64xx_spi_config(sdd);
689 		if (status)
690 			return status;
691 	}
692 
693 	if (!is_polling(sdd) && (xfer->len > fifo_len) &&
694 	    sdd->rx_dma.ch && sdd->tx_dma.ch) {
695 		use_dma = 1;
696 
697 	} else if (is_polling(sdd) && xfer->len > fifo_len) {
698 		tx_buf = xfer->tx_buf;
699 		rx_buf = xfer->rx_buf;
700 		origin_len = xfer->len;
701 
702 		target_len = xfer->len;
703 		if (xfer->len > fifo_len)
704 			xfer->len = fifo_len;
705 	}
706 
707 	do {
708 		spin_lock_irqsave(&sdd->lock, flags);
709 
710 		/* Pending only which is to be done */
711 		sdd->state &= ~RXBUSY;
712 		sdd->state &= ~TXBUSY;
713 
714 		/* Start the signals */
715 		s3c64xx_spi_set_cs(spi, true);
716 
717 		status = s3c64xx_enable_datapath(sdd, xfer, use_dma);
718 
719 		spin_unlock_irqrestore(&sdd->lock, flags);
720 
721 		if (status) {
722 			dev_err(&spi->dev, "failed to enable data path for transfer: %d\n", status);
723 			break;
724 		}
725 
726 		if (use_dma)
727 			status = s3c64xx_wait_for_dma(sdd, xfer);
728 		else
729 			status = s3c64xx_wait_for_pio(sdd, xfer);
730 
731 		if (status) {
732 			dev_err(&spi->dev,
733 				"I/O Error: rx-%d tx-%d rx-%c tx-%c len-%d dma-%d res-(%d)\n",
734 				xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
735 				(sdd->state & RXBUSY) ? 'f' : 'p',
736 				(sdd->state & TXBUSY) ? 'f' : 'p',
737 				xfer->len, use_dma ? 1 : 0, status);
738 
739 			if (use_dma) {
740 				struct dma_tx_state s;
741 
742 				if (xfer->tx_buf && (sdd->state & TXBUSY)) {
743 					dmaengine_pause(sdd->tx_dma.ch);
744 					dmaengine_tx_status(sdd->tx_dma.ch, sdd->tx_dma.cookie, &s);
745 					dmaengine_terminate_all(sdd->tx_dma.ch);
746 					dev_err(&spi->dev, "TX residue: %d\n", s.residue);
747 
748 				}
749 				if (xfer->rx_buf && (sdd->state & RXBUSY)) {
750 					dmaengine_pause(sdd->rx_dma.ch);
751 					dmaengine_tx_status(sdd->rx_dma.ch, sdd->rx_dma.cookie, &s);
752 					dmaengine_terminate_all(sdd->rx_dma.ch);
753 					dev_err(&spi->dev, "RX residue: %d\n", s.residue);
754 				}
755 			}
756 		} else {
757 			s3c64xx_flush_fifo(sdd);
758 		}
759 		if (target_len > 0) {
760 			target_len -= xfer->len;
761 
762 			if (xfer->tx_buf)
763 				xfer->tx_buf += xfer->len;
764 
765 			if (xfer->rx_buf)
766 				xfer->rx_buf += xfer->len;
767 
768 			if (target_len > fifo_len)
769 				xfer->len = fifo_len;
770 			else
771 				xfer->len = target_len;
772 		}
773 	} while (target_len > 0);
774 
775 	if (origin_len) {
776 		/* Restore original xfer buffers and length */
777 		xfer->tx_buf = tx_buf;
778 		xfer->rx_buf = rx_buf;
779 		xfer->len = origin_len;
780 	}
781 
782 	return status;
783 }
784 
785 static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
786 				struct spi_device *spi)
787 {
788 	struct s3c64xx_spi_csinfo *cs;
789 	struct device_node *slave_np, *data_np = NULL;
790 	u32 fb_delay = 0;
791 
792 	slave_np = spi->dev.of_node;
793 	if (!slave_np) {
794 		dev_err(&spi->dev, "device node not found\n");
795 		return ERR_PTR(-EINVAL);
796 	}
797 
798 	data_np = of_get_child_by_name(slave_np, "controller-data");
799 	if (!data_np) {
800 		dev_err(&spi->dev, "child node 'controller-data' not found\n");
801 		return ERR_PTR(-EINVAL);
802 	}
803 
804 	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
805 	if (!cs) {
806 		of_node_put(data_np);
807 		return ERR_PTR(-ENOMEM);
808 	}
809 
810 	of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
811 	cs->fb_delay = fb_delay;
812 	of_node_put(data_np);
813 	return cs;
814 }
815 
816 /*
817  * Here we only check the validity of requested configuration
818  * and save the configuration in a local data-structure.
819  * The controller is actually configured only just before we
820  * get a message to transfer.
821  */
822 static int s3c64xx_spi_setup(struct spi_device *spi)
823 {
824 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
825 	struct s3c64xx_spi_driver_data *sdd;
826 	int err;
827 
828 	sdd = spi_master_get_devdata(spi->master);
829 	if (spi->dev.of_node) {
830 		cs = s3c64xx_get_slave_ctrldata(spi);
831 		spi->controller_data = cs;
832 	} else if (cs) {
833 		/* On non-DT platforms the SPI core will set spi->cs_gpio
834 		 * to -ENOENT. The GPIO pin used to drive the chip select
835 		 * is defined by using platform data so spi->cs_gpio value
836 		 * has to be override to have the proper GPIO pin number.
837 		 */
838 		spi->cs_gpio = cs->line;
839 	}
840 
841 	if (IS_ERR_OR_NULL(cs)) {
842 		dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
843 		return -ENODEV;
844 	}
845 
846 	if (!spi_get_ctldata(spi)) {
847 		if (gpio_is_valid(spi->cs_gpio)) {
848 			err = gpio_request_one(spi->cs_gpio, GPIOF_OUT_INIT_HIGH,
849 					       dev_name(&spi->dev));
850 			if (err) {
851 				dev_err(&spi->dev,
852 					"Failed to get /CS gpio [%d]: %d\n",
853 					spi->cs_gpio, err);
854 				goto err_gpio_req;
855 			}
856 		}
857 
858 		spi_set_ctldata(spi, cs);
859 	}
860 
861 	pm_runtime_get_sync(&sdd->pdev->dev);
862 
863 	/* Check if we can provide the requested rate */
864 	if (!sdd->port_conf->clk_from_cmu) {
865 		u32 psr, speed;
866 
867 		/* Max possible */
868 		speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1);
869 
870 		if (spi->max_speed_hz > speed)
871 			spi->max_speed_hz = speed;
872 
873 		psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1;
874 		psr &= S3C64XX_SPI_PSR_MASK;
875 		if (psr == S3C64XX_SPI_PSR_MASK)
876 			psr--;
877 
878 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
879 		if (spi->max_speed_hz < speed) {
880 			if (psr+1 < S3C64XX_SPI_PSR_MASK) {
881 				psr++;
882 			} else {
883 				err = -EINVAL;
884 				goto setup_exit;
885 			}
886 		}
887 
888 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
889 		if (spi->max_speed_hz >= speed) {
890 			spi->max_speed_hz = speed;
891 		} else {
892 			dev_err(&spi->dev, "Can't set %dHz transfer speed\n",
893 				spi->max_speed_hz);
894 			err = -EINVAL;
895 			goto setup_exit;
896 		}
897 	}
898 
899 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
900 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
901 	s3c64xx_spi_set_cs(spi, false);
902 
903 	return 0;
904 
905 setup_exit:
906 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
907 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
908 	/* setup() returns with device de-selected */
909 	s3c64xx_spi_set_cs(spi, false);
910 
911 	if (gpio_is_valid(spi->cs_gpio))
912 		gpio_free(spi->cs_gpio);
913 	spi_set_ctldata(spi, NULL);
914 
915 err_gpio_req:
916 	if (spi->dev.of_node)
917 		kfree(cs);
918 
919 	return err;
920 }
921 
922 static void s3c64xx_spi_cleanup(struct spi_device *spi)
923 {
924 	struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
925 
926 	if (gpio_is_valid(spi->cs_gpio)) {
927 		gpio_free(spi->cs_gpio);
928 		if (spi->dev.of_node)
929 			kfree(cs);
930 		else {
931 			/* On non-DT platforms, the SPI core sets
932 			 * spi->cs_gpio to -ENOENT and .setup()
933 			 * overrides it with the GPIO pin value
934 			 * passed using platform data.
935 			 */
936 			spi->cs_gpio = -ENOENT;
937 		}
938 	}
939 
940 	spi_set_ctldata(spi, NULL);
941 }
942 
943 static irqreturn_t s3c64xx_spi_irq(int irq, void *data)
944 {
945 	struct s3c64xx_spi_driver_data *sdd = data;
946 	struct spi_master *spi = sdd->master;
947 	unsigned int val, clr = 0;
948 
949 	val = readl(sdd->regs + S3C64XX_SPI_STATUS);
950 
951 	if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) {
952 		clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR;
953 		dev_err(&spi->dev, "RX overrun\n");
954 	}
955 	if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) {
956 		clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR;
957 		dev_err(&spi->dev, "RX underrun\n");
958 	}
959 	if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) {
960 		clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR;
961 		dev_err(&spi->dev, "TX overrun\n");
962 	}
963 	if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) {
964 		clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
965 		dev_err(&spi->dev, "TX underrun\n");
966 	}
967 
968 	/* Clear the pending irq by setting and then clearing it */
969 	writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR);
970 	writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR);
971 
972 	return IRQ_HANDLED;
973 }
974 
975 static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd)
976 {
977 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
978 	void __iomem *regs = sdd->regs;
979 	unsigned int val;
980 
981 	sdd->cur_speed = 0;
982 
983 	if (sci->no_cs)
984 		writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
985 	else if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
986 		writel(S3C64XX_SPI_CS_SIG_INACT, sdd->regs + S3C64XX_SPI_CS_REG);
987 
988 	/* Disable Interrupts - we use Polling if not DMA mode */
989 	writel(0, regs + S3C64XX_SPI_INT_EN);
990 
991 	if (!sdd->port_conf->clk_from_cmu)
992 		writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
993 				regs + S3C64XX_SPI_CLK_CFG);
994 	writel(0, regs + S3C64XX_SPI_MODE_CFG);
995 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
996 
997 	/* Clear any irq pending bits, should set and clear the bits */
998 	val = S3C64XX_SPI_PND_RX_OVERRUN_CLR |
999 		S3C64XX_SPI_PND_RX_UNDERRUN_CLR |
1000 		S3C64XX_SPI_PND_TX_OVERRUN_CLR |
1001 		S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
1002 	writel(val, regs + S3C64XX_SPI_PENDING_CLR);
1003 	writel(0, regs + S3C64XX_SPI_PENDING_CLR);
1004 
1005 	writel(0, regs + S3C64XX_SPI_SWAP_CFG);
1006 
1007 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
1008 	val &= ~S3C64XX_SPI_MODE_4BURST;
1009 	val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
1010 	val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
1011 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
1012 
1013 	s3c64xx_flush_fifo(sdd);
1014 }
1015 
1016 #ifdef CONFIG_OF
1017 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1018 {
1019 	struct s3c64xx_spi_info *sci;
1020 	u32 temp;
1021 
1022 	sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
1023 	if (!sci)
1024 		return ERR_PTR(-ENOMEM);
1025 
1026 	if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
1027 		dev_warn(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
1028 		sci->src_clk_nr = 0;
1029 	} else {
1030 		sci->src_clk_nr = temp;
1031 	}
1032 
1033 	if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
1034 		dev_warn(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
1035 		sci->num_cs = 1;
1036 	} else {
1037 		sci->num_cs = temp;
1038 	}
1039 
1040 	sci->no_cs = of_property_read_bool(dev->of_node, "no-cs-readback");
1041 
1042 	return sci;
1043 }
1044 #else
1045 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1046 {
1047 	return dev_get_platdata(dev);
1048 }
1049 #endif
1050 
1051 static const struct of_device_id s3c64xx_spi_dt_match[];
1052 
1053 static inline struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
1054 						struct platform_device *pdev)
1055 {
1056 #ifdef CONFIG_OF
1057 	if (pdev->dev.of_node) {
1058 		const struct of_device_id *match;
1059 		match = of_match_node(s3c64xx_spi_dt_match, pdev->dev.of_node);
1060 		return (struct s3c64xx_spi_port_config *)match->data;
1061 	}
1062 #endif
1063 	return (struct s3c64xx_spi_port_config *)
1064 			 platform_get_device_id(pdev)->driver_data;
1065 }
1066 
1067 static int s3c64xx_spi_probe(struct platform_device *pdev)
1068 {
1069 	struct resource	*mem_res;
1070 	struct s3c64xx_spi_driver_data *sdd;
1071 	struct s3c64xx_spi_info *sci = dev_get_platdata(&pdev->dev);
1072 	struct spi_master *master;
1073 	int ret, irq;
1074 	char clk_name[16];
1075 
1076 	if (!sci && pdev->dev.of_node) {
1077 		sci = s3c64xx_spi_parse_dt(&pdev->dev);
1078 		if (IS_ERR(sci))
1079 			return PTR_ERR(sci);
1080 	}
1081 
1082 	if (!sci) {
1083 		dev_err(&pdev->dev, "platform_data missing!\n");
1084 		return -ENODEV;
1085 	}
1086 
1087 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1088 	if (mem_res == NULL) {
1089 		dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
1090 		return -ENXIO;
1091 	}
1092 
1093 	irq = platform_get_irq(pdev, 0);
1094 	if (irq < 0) {
1095 		dev_warn(&pdev->dev, "Failed to get IRQ: %d\n", irq);
1096 		return irq;
1097 	}
1098 
1099 	master = spi_alloc_master(&pdev->dev,
1100 				sizeof(struct s3c64xx_spi_driver_data));
1101 	if (master == NULL) {
1102 		dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
1103 		return -ENOMEM;
1104 	}
1105 
1106 	platform_set_drvdata(pdev, master);
1107 
1108 	sdd = spi_master_get_devdata(master);
1109 	sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
1110 	sdd->master = master;
1111 	sdd->cntrlr_info = sci;
1112 	sdd->pdev = pdev;
1113 	sdd->sfr_start = mem_res->start;
1114 	if (pdev->dev.of_node) {
1115 		ret = of_alias_get_id(pdev->dev.of_node, "spi");
1116 		if (ret < 0) {
1117 			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
1118 				ret);
1119 			goto err_deref_master;
1120 		}
1121 		sdd->port_id = ret;
1122 	} else {
1123 		sdd->port_id = pdev->id;
1124 	}
1125 
1126 	sdd->cur_bpw = 8;
1127 
1128 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
1129 	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
1130 
1131 	master->dev.of_node = pdev->dev.of_node;
1132 	master->bus_num = sdd->port_id;
1133 	master->setup = s3c64xx_spi_setup;
1134 	master->cleanup = s3c64xx_spi_cleanup;
1135 	master->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
1136 	master->prepare_message = s3c64xx_spi_prepare_message;
1137 	master->transfer_one = s3c64xx_spi_transfer_one;
1138 	master->num_chipselect = sci->num_cs;
1139 	master->dma_alignment = 8;
1140 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
1141 					SPI_BPW_MASK(8);
1142 	/* the spi->mode bits understood by this driver: */
1143 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1144 	master->auto_runtime_pm = true;
1145 	if (!is_polling(sdd))
1146 		master->can_dma = s3c64xx_spi_can_dma;
1147 
1148 	sdd->regs = devm_ioremap_resource(&pdev->dev, mem_res);
1149 	if (IS_ERR(sdd->regs)) {
1150 		ret = PTR_ERR(sdd->regs);
1151 		goto err_deref_master;
1152 	}
1153 
1154 	if (sci->cfg_gpio && sci->cfg_gpio()) {
1155 		dev_err(&pdev->dev, "Unable to config gpio\n");
1156 		ret = -EBUSY;
1157 		goto err_deref_master;
1158 	}
1159 
1160 	/* Setup clocks */
1161 	sdd->clk = devm_clk_get(&pdev->dev, "spi");
1162 	if (IS_ERR(sdd->clk)) {
1163 		dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
1164 		ret = PTR_ERR(sdd->clk);
1165 		goto err_deref_master;
1166 	}
1167 
1168 	ret = clk_prepare_enable(sdd->clk);
1169 	if (ret) {
1170 		dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
1171 		goto err_deref_master;
1172 	}
1173 
1174 	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
1175 	sdd->src_clk = devm_clk_get(&pdev->dev, clk_name);
1176 	if (IS_ERR(sdd->src_clk)) {
1177 		dev_err(&pdev->dev,
1178 			"Unable to acquire clock '%s'\n", clk_name);
1179 		ret = PTR_ERR(sdd->src_clk);
1180 		goto err_disable_clk;
1181 	}
1182 
1183 	ret = clk_prepare_enable(sdd->src_clk);
1184 	if (ret) {
1185 		dev_err(&pdev->dev, "Couldn't enable clock '%s'\n", clk_name);
1186 		goto err_disable_clk;
1187 	}
1188 
1189 	if (sdd->port_conf->clk_ioclk) {
1190 		sdd->ioclk = devm_clk_get(&pdev->dev, "spi_ioclk");
1191 		if (IS_ERR(sdd->ioclk)) {
1192 			dev_err(&pdev->dev, "Unable to acquire 'ioclk'\n");
1193 			ret = PTR_ERR(sdd->ioclk);
1194 			goto err_disable_src_clk;
1195 		}
1196 
1197 		ret = clk_prepare_enable(sdd->ioclk);
1198 		if (ret) {
1199 			dev_err(&pdev->dev, "Couldn't enable clock 'ioclk'\n");
1200 			goto err_disable_src_clk;
1201 		}
1202 	}
1203 
1204 	if (!is_polling(sdd)) {
1205 		/* Acquire DMA channels */
1206 		sdd->rx_dma.ch = dma_request_chan(&pdev->dev, "rx");
1207 		if (IS_ERR(sdd->rx_dma.ch)) {
1208 			dev_err(&pdev->dev, "Failed to get RX DMA channel\n");
1209 			ret = PTR_ERR(sdd->rx_dma.ch);
1210 			goto err_disable_io_clk;
1211 		}
1212 		sdd->tx_dma.ch = dma_request_chan(&pdev->dev, "tx");
1213 		if (IS_ERR(sdd->tx_dma.ch)) {
1214 			dev_err(&pdev->dev, "Failed to get TX DMA channel\n");
1215 			ret = PTR_ERR(sdd->tx_dma.ch);
1216 			goto err_release_rx_dma;
1217 		}
1218 	}
1219 
1220 	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1221 	pm_runtime_use_autosuspend(&pdev->dev);
1222 	pm_runtime_set_active(&pdev->dev);
1223 	pm_runtime_enable(&pdev->dev);
1224 	pm_runtime_get_sync(&pdev->dev);
1225 
1226 	/* Setup Deufult Mode */
1227 	s3c64xx_spi_hwinit(sdd);
1228 
1229 	spin_lock_init(&sdd->lock);
1230 	init_completion(&sdd->xfer_completion);
1231 
1232 	ret = devm_request_irq(&pdev->dev, irq, s3c64xx_spi_irq, 0,
1233 				"spi-s3c64xx", sdd);
1234 	if (ret != 0) {
1235 		dev_err(&pdev->dev, "Failed to request IRQ %d: %d\n",
1236 			irq, ret);
1237 		goto err_pm_put;
1238 	}
1239 
1240 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1241 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1242 	       sdd->regs + S3C64XX_SPI_INT_EN);
1243 
1244 	ret = devm_spi_register_master(&pdev->dev, master);
1245 	if (ret != 0) {
1246 		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
1247 		goto err_pm_put;
1248 	}
1249 
1250 	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",
1251 					sdd->port_id, master->num_chipselect);
1252 	dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\n",
1253 					mem_res, (FIFO_LVL_MASK(sdd) >> 1) + 1);
1254 
1255 	pm_runtime_mark_last_busy(&pdev->dev);
1256 	pm_runtime_put_autosuspend(&pdev->dev);
1257 
1258 	return 0;
1259 
1260 err_pm_put:
1261 	pm_runtime_put_noidle(&pdev->dev);
1262 	pm_runtime_disable(&pdev->dev);
1263 	pm_runtime_set_suspended(&pdev->dev);
1264 
1265 	if (!is_polling(sdd))
1266 		dma_release_channel(sdd->tx_dma.ch);
1267 err_release_rx_dma:
1268 	if (!is_polling(sdd))
1269 		dma_release_channel(sdd->rx_dma.ch);
1270 err_disable_io_clk:
1271 	clk_disable_unprepare(sdd->ioclk);
1272 err_disable_src_clk:
1273 	clk_disable_unprepare(sdd->src_clk);
1274 err_disable_clk:
1275 	clk_disable_unprepare(sdd->clk);
1276 err_deref_master:
1277 	spi_master_put(master);
1278 
1279 	return ret;
1280 }
1281 
1282 static int s3c64xx_spi_remove(struct platform_device *pdev)
1283 {
1284 	struct spi_master *master = platform_get_drvdata(pdev);
1285 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1286 
1287 	pm_runtime_get_sync(&pdev->dev);
1288 
1289 	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
1290 
1291 	if (!is_polling(sdd)) {
1292 		dma_release_channel(sdd->rx_dma.ch);
1293 		dma_release_channel(sdd->tx_dma.ch);
1294 	}
1295 
1296 	clk_disable_unprepare(sdd->ioclk);
1297 
1298 	clk_disable_unprepare(sdd->src_clk);
1299 
1300 	clk_disable_unprepare(sdd->clk);
1301 
1302 	pm_runtime_put_noidle(&pdev->dev);
1303 	pm_runtime_disable(&pdev->dev);
1304 	pm_runtime_set_suspended(&pdev->dev);
1305 
1306 	return 0;
1307 }
1308 
1309 #ifdef CONFIG_PM_SLEEP
1310 static int s3c64xx_spi_suspend(struct device *dev)
1311 {
1312 	struct spi_master *master = dev_get_drvdata(dev);
1313 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1314 
1315 	int ret = spi_master_suspend(master);
1316 	if (ret)
1317 		return ret;
1318 
1319 	ret = pm_runtime_force_suspend(dev);
1320 	if (ret < 0)
1321 		return ret;
1322 
1323 	sdd->cur_speed = 0; /* Output Clock is stopped */
1324 
1325 	return 0;
1326 }
1327 
1328 static int s3c64xx_spi_resume(struct device *dev)
1329 {
1330 	struct spi_master *master = dev_get_drvdata(dev);
1331 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1332 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1333 	int ret;
1334 
1335 	if (sci->cfg_gpio)
1336 		sci->cfg_gpio();
1337 
1338 	ret = pm_runtime_force_resume(dev);
1339 	if (ret < 0)
1340 		return ret;
1341 
1342 	return spi_master_resume(master);
1343 }
1344 #endif /* CONFIG_PM_SLEEP */
1345 
1346 #ifdef CONFIG_PM
1347 static int s3c64xx_spi_runtime_suspend(struct device *dev)
1348 {
1349 	struct spi_master *master = dev_get_drvdata(dev);
1350 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1351 
1352 	clk_disable_unprepare(sdd->clk);
1353 	clk_disable_unprepare(sdd->src_clk);
1354 	clk_disable_unprepare(sdd->ioclk);
1355 
1356 	return 0;
1357 }
1358 
1359 static int s3c64xx_spi_runtime_resume(struct device *dev)
1360 {
1361 	struct spi_master *master = dev_get_drvdata(dev);
1362 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1363 	int ret;
1364 
1365 	if (sdd->port_conf->clk_ioclk) {
1366 		ret = clk_prepare_enable(sdd->ioclk);
1367 		if (ret != 0)
1368 			return ret;
1369 	}
1370 
1371 	ret = clk_prepare_enable(sdd->src_clk);
1372 	if (ret != 0)
1373 		goto err_disable_ioclk;
1374 
1375 	ret = clk_prepare_enable(sdd->clk);
1376 	if (ret != 0)
1377 		goto err_disable_src_clk;
1378 
1379 	s3c64xx_spi_hwinit(sdd);
1380 
1381 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1382 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1383 	       sdd->regs + S3C64XX_SPI_INT_EN);
1384 
1385 	return 0;
1386 
1387 err_disable_src_clk:
1388 	clk_disable_unprepare(sdd->src_clk);
1389 err_disable_ioclk:
1390 	clk_disable_unprepare(sdd->ioclk);
1391 
1392 	return ret;
1393 }
1394 #endif /* CONFIG_PM */
1395 
1396 static const struct dev_pm_ops s3c64xx_spi_pm = {
1397 	SET_SYSTEM_SLEEP_PM_OPS(s3c64xx_spi_suspend, s3c64xx_spi_resume)
1398 	SET_RUNTIME_PM_OPS(s3c64xx_spi_runtime_suspend,
1399 			   s3c64xx_spi_runtime_resume, NULL)
1400 };
1401 
1402 static struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
1403 	.fifo_lvl_mask	= { 0x7f },
1404 	.rx_lvl_offset	= 13,
1405 	.tx_st_done	= 21,
1406 	.high_speed	= true,
1407 };
1408 
1409 static struct s3c64xx_spi_port_config s3c6410_spi_port_config = {
1410 	.fifo_lvl_mask	= { 0x7f, 0x7F },
1411 	.rx_lvl_offset	= 13,
1412 	.tx_st_done	= 21,
1413 };
1414 
1415 static struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
1416 	.fifo_lvl_mask	= { 0x1ff, 0x7F },
1417 	.rx_lvl_offset	= 15,
1418 	.tx_st_done	= 25,
1419 	.high_speed	= true,
1420 };
1421 
1422 static struct s3c64xx_spi_port_config exynos4_spi_port_config = {
1423 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F },
1424 	.rx_lvl_offset	= 15,
1425 	.tx_st_done	= 25,
1426 	.high_speed	= true,
1427 	.clk_from_cmu	= true,
1428 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1429 };
1430 
1431 static struct s3c64xx_spi_port_config exynos7_spi_port_config = {
1432 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},
1433 	.rx_lvl_offset	= 15,
1434 	.tx_st_done	= 25,
1435 	.high_speed	= true,
1436 	.clk_from_cmu	= true,
1437 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1438 };
1439 
1440 static struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
1441 	.fifo_lvl_mask	= { 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff},
1442 	.rx_lvl_offset	= 15,
1443 	.tx_st_done	= 25,
1444 	.high_speed	= true,
1445 	.clk_from_cmu	= true,
1446 	.clk_ioclk	= true,
1447 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1448 };
1449 
1450 static const struct platform_device_id s3c64xx_spi_driver_ids[] = {
1451 	{
1452 		.name		= "s3c2443-spi",
1453 		.driver_data	= (kernel_ulong_t)&s3c2443_spi_port_config,
1454 	}, {
1455 		.name		= "s3c6410-spi",
1456 		.driver_data	= (kernel_ulong_t)&s3c6410_spi_port_config,
1457 	},
1458 	{ },
1459 };
1460 
1461 static const struct of_device_id s3c64xx_spi_dt_match[] = {
1462 	{ .compatible = "samsung,s3c2443-spi",
1463 			.data = (void *)&s3c2443_spi_port_config,
1464 	},
1465 	{ .compatible = "samsung,s3c6410-spi",
1466 			.data = (void *)&s3c6410_spi_port_config,
1467 	},
1468 	{ .compatible = "samsung,s5pv210-spi",
1469 			.data = (void *)&s5pv210_spi_port_config,
1470 	},
1471 	{ .compatible = "samsung,exynos4210-spi",
1472 			.data = (void *)&exynos4_spi_port_config,
1473 	},
1474 	{ .compatible = "samsung,exynos7-spi",
1475 			.data = (void *)&exynos7_spi_port_config,
1476 	},
1477 	{ .compatible = "samsung,exynos5433-spi",
1478 			.data = (void *)&exynos5433_spi_port_config,
1479 	},
1480 	{ },
1481 };
1482 MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
1483 
1484 static struct platform_driver s3c64xx_spi_driver = {
1485 	.driver = {
1486 		.name	= "s3c64xx-spi",
1487 		.pm = &s3c64xx_spi_pm,
1488 		.of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
1489 	},
1490 	.probe = s3c64xx_spi_probe,
1491 	.remove = s3c64xx_spi_remove,
1492 	.id_table = s3c64xx_spi_driver_ids,
1493 };
1494 MODULE_ALIAS("platform:s3c64xx-spi");
1495 
1496 module_platform_driver(s3c64xx_spi_driver);
1497 
1498 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1499 MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1500 MODULE_LICENSE("GPL");
1501