xref: /openbmc/linux/drivers/spi/spi-s3c64xx.c (revision 80483c3a)
1 /*
2  * Copyright (C) 2009 Samsung Electronics Ltd.
3  *	Jaswinder Singh <jassi.brar@samsung.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  */
15 
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/interrupt.h>
19 #include <linux/delay.h>
20 #include <linux/clk.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/dmaengine.h>
23 #include <linux/platform_device.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/spi/spi.h>
26 #include <linux/gpio.h>
27 #include <linux/of.h>
28 #include <linux/of_gpio.h>
29 
30 #include <linux/platform_data/spi-s3c64xx.h>
31 
32 #define MAX_SPI_PORTS		6
33 #define S3C64XX_SPI_QUIRK_POLL		(1 << 0)
34 #define S3C64XX_SPI_QUIRK_CS_AUTO	(1 << 1)
35 #define AUTOSUSPEND_TIMEOUT	2000
36 
37 /* Registers and bit-fields */
38 
39 #define S3C64XX_SPI_CH_CFG		0x00
40 #define S3C64XX_SPI_CLK_CFG		0x04
41 #define S3C64XX_SPI_MODE_CFG	0x08
42 #define S3C64XX_SPI_SLAVE_SEL	0x0C
43 #define S3C64XX_SPI_INT_EN		0x10
44 #define S3C64XX_SPI_STATUS		0x14
45 #define S3C64XX_SPI_TX_DATA		0x18
46 #define S3C64XX_SPI_RX_DATA		0x1C
47 #define S3C64XX_SPI_PACKET_CNT	0x20
48 #define S3C64XX_SPI_PENDING_CLR	0x24
49 #define S3C64XX_SPI_SWAP_CFG	0x28
50 #define S3C64XX_SPI_FB_CLK		0x2C
51 
52 #define S3C64XX_SPI_CH_HS_EN		(1<<6)	/* High Speed Enable */
53 #define S3C64XX_SPI_CH_SW_RST		(1<<5)
54 #define S3C64XX_SPI_CH_SLAVE		(1<<4)
55 #define S3C64XX_SPI_CPOL_L		(1<<3)
56 #define S3C64XX_SPI_CPHA_B		(1<<2)
57 #define S3C64XX_SPI_CH_RXCH_ON		(1<<1)
58 #define S3C64XX_SPI_CH_TXCH_ON		(1<<0)
59 
60 #define S3C64XX_SPI_CLKSEL_SRCMSK	(3<<9)
61 #define S3C64XX_SPI_CLKSEL_SRCSHFT	9
62 #define S3C64XX_SPI_ENCLK_ENABLE	(1<<8)
63 #define S3C64XX_SPI_PSR_MASK		0xff
64 
65 #define S3C64XX_SPI_MODE_CH_TSZ_BYTE		(0<<29)
66 #define S3C64XX_SPI_MODE_CH_TSZ_HALFWORD	(1<<29)
67 #define S3C64XX_SPI_MODE_CH_TSZ_WORD		(2<<29)
68 #define S3C64XX_SPI_MODE_CH_TSZ_MASK		(3<<29)
69 #define S3C64XX_SPI_MODE_BUS_TSZ_BYTE		(0<<17)
70 #define S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD	(1<<17)
71 #define S3C64XX_SPI_MODE_BUS_TSZ_WORD		(2<<17)
72 #define S3C64XX_SPI_MODE_BUS_TSZ_MASK		(3<<17)
73 #define S3C64XX_SPI_MODE_RXDMA_ON		(1<<2)
74 #define S3C64XX_SPI_MODE_TXDMA_ON		(1<<1)
75 #define S3C64XX_SPI_MODE_4BURST			(1<<0)
76 
77 #define S3C64XX_SPI_SLAVE_AUTO			(1<<1)
78 #define S3C64XX_SPI_SLAVE_SIG_INACT		(1<<0)
79 #define S3C64XX_SPI_SLAVE_NSC_CNT_2		(2<<4)
80 
81 #define S3C64XX_SPI_INT_TRAILING_EN		(1<<6)
82 #define S3C64XX_SPI_INT_RX_OVERRUN_EN		(1<<5)
83 #define S3C64XX_SPI_INT_RX_UNDERRUN_EN		(1<<4)
84 #define S3C64XX_SPI_INT_TX_OVERRUN_EN		(1<<3)
85 #define S3C64XX_SPI_INT_TX_UNDERRUN_EN		(1<<2)
86 #define S3C64XX_SPI_INT_RX_FIFORDY_EN		(1<<1)
87 #define S3C64XX_SPI_INT_TX_FIFORDY_EN		(1<<0)
88 
89 #define S3C64XX_SPI_ST_RX_OVERRUN_ERR		(1<<5)
90 #define S3C64XX_SPI_ST_RX_UNDERRUN_ERR	(1<<4)
91 #define S3C64XX_SPI_ST_TX_OVERRUN_ERR		(1<<3)
92 #define S3C64XX_SPI_ST_TX_UNDERRUN_ERR	(1<<2)
93 #define S3C64XX_SPI_ST_RX_FIFORDY		(1<<1)
94 #define S3C64XX_SPI_ST_TX_FIFORDY		(1<<0)
95 
96 #define S3C64XX_SPI_PACKET_CNT_EN		(1<<16)
97 
98 #define S3C64XX_SPI_PND_TX_UNDERRUN_CLR		(1<<4)
99 #define S3C64XX_SPI_PND_TX_OVERRUN_CLR		(1<<3)
100 #define S3C64XX_SPI_PND_RX_UNDERRUN_CLR		(1<<2)
101 #define S3C64XX_SPI_PND_RX_OVERRUN_CLR		(1<<1)
102 #define S3C64XX_SPI_PND_TRAILING_CLR		(1<<0)
103 
104 #define S3C64XX_SPI_SWAP_RX_HALF_WORD		(1<<7)
105 #define S3C64XX_SPI_SWAP_RX_BYTE		(1<<6)
106 #define S3C64XX_SPI_SWAP_RX_BIT			(1<<5)
107 #define S3C64XX_SPI_SWAP_RX_EN			(1<<4)
108 #define S3C64XX_SPI_SWAP_TX_HALF_WORD		(1<<3)
109 #define S3C64XX_SPI_SWAP_TX_BYTE		(1<<2)
110 #define S3C64XX_SPI_SWAP_TX_BIT			(1<<1)
111 #define S3C64XX_SPI_SWAP_TX_EN			(1<<0)
112 
113 #define S3C64XX_SPI_FBCLK_MSK		(3<<0)
114 
115 #define FIFO_LVL_MASK(i) ((i)->port_conf->fifo_lvl_mask[i->port_id])
116 #define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & \
117 				(1 << (i)->port_conf->tx_st_done)) ? 1 : 0)
118 #define TX_FIFO_LVL(v, i) (((v) >> 6) & FIFO_LVL_MASK(i))
119 #define RX_FIFO_LVL(v, i) (((v) >> (i)->port_conf->rx_lvl_offset) & \
120 					FIFO_LVL_MASK(i))
121 
122 #define S3C64XX_SPI_MAX_TRAILCNT	0x3ff
123 #define S3C64XX_SPI_TRAILCNT_OFF	19
124 
125 #define S3C64XX_SPI_TRAILCNT		S3C64XX_SPI_MAX_TRAILCNT
126 
127 #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
128 #define is_polling(x)	(x->port_conf->quirks & S3C64XX_SPI_QUIRK_POLL)
129 
130 #define RXBUSY    (1<<2)
131 #define TXBUSY    (1<<3)
132 
133 struct s3c64xx_spi_dma_data {
134 	struct dma_chan *ch;
135 	enum dma_transfer_direction direction;
136 };
137 
138 /**
139  * struct s3c64xx_spi_info - SPI Controller hardware info
140  * @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
141  * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
142  * @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
143  * @high_speed: True, if the controller supports HIGH_SPEED_EN bit.
144  * @clk_from_cmu: True, if the controller does not include a clock mux and
145  *	prescaler unit.
146  *
147  * The Samsung s3c64xx SPI controller are used on various Samsung SoC's but
148  * differ in some aspects such as the size of the fifo and spi bus clock
149  * setup. Such differences are specified to the driver using this structure
150  * which is provided as driver data to the driver.
151  */
152 struct s3c64xx_spi_port_config {
153 	int	fifo_lvl_mask[MAX_SPI_PORTS];
154 	int	rx_lvl_offset;
155 	int	tx_st_done;
156 	int	quirks;
157 	bool	high_speed;
158 	bool	clk_from_cmu;
159 	bool	clk_ioclk;
160 };
161 
162 /**
163  * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
164  * @clk: Pointer to the spi clock.
165  * @src_clk: Pointer to the clock used to generate SPI signals.
166  * @ioclk: Pointer to the i/o clock between master and slave
167  * @master: Pointer to the SPI Protocol master.
168  * @cntrlr_info: Platform specific data for the controller this driver manages.
169  * @tgl_spi: Pointer to the last CS left untoggled by the cs_change hint.
170  * @lock: Controller specific lock.
171  * @state: Set of FLAGS to indicate status.
172  * @rx_dmach: Controller's DMA channel for Rx.
173  * @tx_dmach: Controller's DMA channel for Tx.
174  * @sfr_start: BUS address of SPI controller regs.
175  * @regs: Pointer to ioremap'ed controller registers.
176  * @irq: interrupt
177  * @xfer_completion: To indicate completion of xfer task.
178  * @cur_mode: Stores the active configuration of the controller.
179  * @cur_bpw: Stores the active bits per word settings.
180  * @cur_speed: Stores the active xfer clock speed.
181  */
182 struct s3c64xx_spi_driver_data {
183 	void __iomem                    *regs;
184 	struct clk                      *clk;
185 	struct clk                      *src_clk;
186 	struct clk                      *ioclk;
187 	struct platform_device          *pdev;
188 	struct spi_master               *master;
189 	struct s3c64xx_spi_info  *cntrlr_info;
190 	struct spi_device               *tgl_spi;
191 	spinlock_t                      lock;
192 	unsigned long                   sfr_start;
193 	struct completion               xfer_completion;
194 	unsigned                        state;
195 	unsigned                        cur_mode, cur_bpw;
196 	unsigned                        cur_speed;
197 	struct s3c64xx_spi_dma_data	rx_dma;
198 	struct s3c64xx_spi_dma_data	tx_dma;
199 	struct s3c64xx_spi_port_config	*port_conf;
200 	unsigned int			port_id;
201 };
202 
203 static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
204 {
205 	void __iomem *regs = sdd->regs;
206 	unsigned long loops;
207 	u32 val;
208 
209 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
210 
211 	val = readl(regs + S3C64XX_SPI_CH_CFG);
212 	val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON);
213 	writel(val, regs + S3C64XX_SPI_CH_CFG);
214 
215 	val = readl(regs + S3C64XX_SPI_CH_CFG);
216 	val |= S3C64XX_SPI_CH_SW_RST;
217 	val &= ~S3C64XX_SPI_CH_HS_EN;
218 	writel(val, regs + S3C64XX_SPI_CH_CFG);
219 
220 	/* Flush TxFIFO*/
221 	loops = msecs_to_loops(1);
222 	do {
223 		val = readl(regs + S3C64XX_SPI_STATUS);
224 	} while (TX_FIFO_LVL(val, sdd) && loops--);
225 
226 	if (loops == 0)
227 		dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n");
228 
229 	/* Flush RxFIFO*/
230 	loops = msecs_to_loops(1);
231 	do {
232 		val = readl(regs + S3C64XX_SPI_STATUS);
233 		if (RX_FIFO_LVL(val, sdd))
234 			readl(regs + S3C64XX_SPI_RX_DATA);
235 		else
236 			break;
237 	} while (loops--);
238 
239 	if (loops == 0)
240 		dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n");
241 
242 	val = readl(regs + S3C64XX_SPI_CH_CFG);
243 	val &= ~S3C64XX_SPI_CH_SW_RST;
244 	writel(val, regs + S3C64XX_SPI_CH_CFG);
245 
246 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
247 	val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
248 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
249 }
250 
251 static void s3c64xx_spi_dmacb(void *data)
252 {
253 	struct s3c64xx_spi_driver_data *sdd;
254 	struct s3c64xx_spi_dma_data *dma = data;
255 	unsigned long flags;
256 
257 	if (dma->direction == DMA_DEV_TO_MEM)
258 		sdd = container_of(data,
259 			struct s3c64xx_spi_driver_data, rx_dma);
260 	else
261 		sdd = container_of(data,
262 			struct s3c64xx_spi_driver_data, tx_dma);
263 
264 	spin_lock_irqsave(&sdd->lock, flags);
265 
266 	if (dma->direction == DMA_DEV_TO_MEM) {
267 		sdd->state &= ~RXBUSY;
268 		if (!(sdd->state & TXBUSY))
269 			complete(&sdd->xfer_completion);
270 	} else {
271 		sdd->state &= ~TXBUSY;
272 		if (!(sdd->state & RXBUSY))
273 			complete(&sdd->xfer_completion);
274 	}
275 
276 	spin_unlock_irqrestore(&sdd->lock, flags);
277 }
278 
279 static void prepare_dma(struct s3c64xx_spi_dma_data *dma,
280 			struct sg_table *sgt)
281 {
282 	struct s3c64xx_spi_driver_data *sdd;
283 	struct dma_slave_config config;
284 	struct dma_async_tx_descriptor *desc;
285 
286 	memset(&config, 0, sizeof(config));
287 
288 	if (dma->direction == DMA_DEV_TO_MEM) {
289 		sdd = container_of((void *)dma,
290 			struct s3c64xx_spi_driver_data, rx_dma);
291 		config.direction = dma->direction;
292 		config.src_addr = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
293 		config.src_addr_width = sdd->cur_bpw / 8;
294 		config.src_maxburst = 1;
295 		dmaengine_slave_config(dma->ch, &config);
296 	} else {
297 		sdd = container_of((void *)dma,
298 			struct s3c64xx_spi_driver_data, tx_dma);
299 		config.direction = dma->direction;
300 		config.dst_addr = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
301 		config.dst_addr_width = sdd->cur_bpw / 8;
302 		config.dst_maxburst = 1;
303 		dmaengine_slave_config(dma->ch, &config);
304 	}
305 
306 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
307 				       dma->direction, DMA_PREP_INTERRUPT);
308 
309 	desc->callback = s3c64xx_spi_dmacb;
310 	desc->callback_param = dma;
311 
312 	dmaengine_submit(desc);
313 	dma_async_issue_pending(dma->ch);
314 }
315 
316 static void s3c64xx_spi_set_cs(struct spi_device *spi, bool enable)
317 {
318 	struct s3c64xx_spi_driver_data *sdd =
319 					spi_master_get_devdata(spi->master);
320 
321 	if (sdd->cntrlr_info->no_cs)
322 		return;
323 
324 	if (enable) {
325 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO)) {
326 			writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
327 		} else {
328 			u32 ssel = readl(sdd->regs + S3C64XX_SPI_SLAVE_SEL);
329 
330 			ssel |= (S3C64XX_SPI_SLAVE_AUTO |
331 						S3C64XX_SPI_SLAVE_NSC_CNT_2);
332 			writel(ssel, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
333 		}
334 	} else {
335 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
336 			writel(S3C64XX_SPI_SLAVE_SIG_INACT,
337 			       sdd->regs + S3C64XX_SPI_SLAVE_SEL);
338 	}
339 }
340 
341 static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
342 {
343 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
344 	dma_filter_fn filter = sdd->cntrlr_info->filter;
345 	struct device *dev = &sdd->pdev->dev;
346 	dma_cap_mask_t mask;
347 
348 	if (is_polling(sdd))
349 		return 0;
350 
351 	dma_cap_zero(mask);
352 	dma_cap_set(DMA_SLAVE, mask);
353 
354 	/* Acquire DMA channels */
355 	sdd->rx_dma.ch = dma_request_slave_channel_compat(mask, filter,
356 			   sdd->cntrlr_info->dma_rx, dev, "rx");
357 	if (!sdd->rx_dma.ch) {
358 		dev_err(dev, "Failed to get RX DMA channel\n");
359 		return -EBUSY;
360 	}
361 	spi->dma_rx = sdd->rx_dma.ch;
362 
363 	sdd->tx_dma.ch = dma_request_slave_channel_compat(mask, filter,
364 			   sdd->cntrlr_info->dma_tx, dev, "tx");
365 	if (!sdd->tx_dma.ch) {
366 		dev_err(dev, "Failed to get TX DMA channel\n");
367 		dma_release_channel(sdd->rx_dma.ch);
368 		return -EBUSY;
369 	}
370 	spi->dma_tx = sdd->tx_dma.ch;
371 
372 	return 0;
373 }
374 
375 static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
376 {
377 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
378 
379 	/* Free DMA channels */
380 	if (!is_polling(sdd)) {
381 		dma_release_channel(sdd->rx_dma.ch);
382 		dma_release_channel(sdd->tx_dma.ch);
383 	}
384 
385 	return 0;
386 }
387 
388 static bool s3c64xx_spi_can_dma(struct spi_master *master,
389 				struct spi_device *spi,
390 				struct spi_transfer *xfer)
391 {
392 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
393 
394 	return xfer->len > (FIFO_LVL_MASK(sdd) >> 1) + 1;
395 }
396 
397 static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
398 				struct spi_device *spi,
399 				struct spi_transfer *xfer, int dma_mode)
400 {
401 	void __iomem *regs = sdd->regs;
402 	u32 modecfg, chcfg;
403 
404 	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
405 	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
406 
407 	chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
408 	chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
409 
410 	if (dma_mode) {
411 		chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
412 	} else {
413 		/* Always shift in data in FIFO, even if xfer is Tx only,
414 		 * this helps setting PCKT_CNT value for generating clocks
415 		 * as exactly needed.
416 		 */
417 		chcfg |= S3C64XX_SPI_CH_RXCH_ON;
418 		writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
419 					| S3C64XX_SPI_PACKET_CNT_EN,
420 					regs + S3C64XX_SPI_PACKET_CNT);
421 	}
422 
423 	if (xfer->tx_buf != NULL) {
424 		sdd->state |= TXBUSY;
425 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
426 		if (dma_mode) {
427 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
428 			prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
429 		} else {
430 			switch (sdd->cur_bpw) {
431 			case 32:
432 				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
433 					xfer->tx_buf, xfer->len / 4);
434 				break;
435 			case 16:
436 				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
437 					xfer->tx_buf, xfer->len / 2);
438 				break;
439 			default:
440 				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
441 					xfer->tx_buf, xfer->len);
442 				break;
443 			}
444 		}
445 	}
446 
447 	if (xfer->rx_buf != NULL) {
448 		sdd->state |= RXBUSY;
449 
450 		if (sdd->port_conf->high_speed && sdd->cur_speed >= 30000000UL
451 					&& !(sdd->cur_mode & SPI_CPHA))
452 			chcfg |= S3C64XX_SPI_CH_HS_EN;
453 
454 		if (dma_mode) {
455 			modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
456 			chcfg |= S3C64XX_SPI_CH_RXCH_ON;
457 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
458 					| S3C64XX_SPI_PACKET_CNT_EN,
459 					regs + S3C64XX_SPI_PACKET_CNT);
460 			prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
461 		}
462 	}
463 
464 	writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
465 	writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
466 }
467 
468 static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
469 					int timeout_ms)
470 {
471 	void __iomem *regs = sdd->regs;
472 	unsigned long val = 1;
473 	u32 status;
474 
475 	/* max fifo depth available */
476 	u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
477 
478 	if (timeout_ms)
479 		val = msecs_to_loops(timeout_ms);
480 
481 	do {
482 		status = readl(regs + S3C64XX_SPI_STATUS);
483 	} while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
484 
485 	/* return the actual received data length */
486 	return RX_FIFO_LVL(status, sdd);
487 }
488 
489 static int wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
490 			struct spi_transfer *xfer)
491 {
492 	void __iomem *regs = sdd->regs;
493 	unsigned long val;
494 	u32 status;
495 	int ms;
496 
497 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
498 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
499 	ms += 10; /* some tolerance */
500 
501 	val = msecs_to_jiffies(ms) + 10;
502 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
503 
504 	/*
505 	 * If the previous xfer was completed within timeout, then
506 	 * proceed further else return -EIO.
507 	 * DmaTx returns after simply writing data in the FIFO,
508 	 * w/o waiting for real transmission on the bus to finish.
509 	 * DmaRx returns only after Dma read data from FIFO which
510 	 * needs bus transmission to finish, so we don't worry if
511 	 * Xfer involved Rx(with or without Tx).
512 	 */
513 	if (val && !xfer->rx_buf) {
514 		val = msecs_to_loops(10);
515 		status = readl(regs + S3C64XX_SPI_STATUS);
516 		while ((TX_FIFO_LVL(status, sdd)
517 			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
518 		       && --val) {
519 			cpu_relax();
520 			status = readl(regs + S3C64XX_SPI_STATUS);
521 		}
522 
523 	}
524 
525 	/* If timed out while checking rx/tx status return error */
526 	if (!val)
527 		return -EIO;
528 
529 	return 0;
530 }
531 
532 static int wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
533 			struct spi_transfer *xfer)
534 {
535 	void __iomem *regs = sdd->regs;
536 	unsigned long val;
537 	u32 status;
538 	int loops;
539 	u32 cpy_len;
540 	u8 *buf;
541 	int ms;
542 
543 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
544 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
545 	ms += 10; /* some tolerance */
546 
547 	val = msecs_to_loops(ms);
548 	do {
549 		status = readl(regs + S3C64XX_SPI_STATUS);
550 	} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
551 
552 
553 	/* If it was only Tx */
554 	if (!xfer->rx_buf) {
555 		sdd->state &= ~TXBUSY;
556 		return 0;
557 	}
558 
559 	/*
560 	 * If the receive length is bigger than the controller fifo
561 	 * size, calculate the loops and read the fifo as many times.
562 	 * loops = length / max fifo size (calculated by using the
563 	 * fifo mask).
564 	 * For any size less than the fifo size the below code is
565 	 * executed atleast once.
566 	 */
567 	loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
568 	buf = xfer->rx_buf;
569 	do {
570 		/* wait for data to be received in the fifo */
571 		cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
572 						       (loops ? ms : 0));
573 
574 		switch (sdd->cur_bpw) {
575 		case 32:
576 			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
577 				     buf, cpy_len / 4);
578 			break;
579 		case 16:
580 			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
581 				     buf, cpy_len / 2);
582 			break;
583 		default:
584 			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
585 				    buf, cpy_len);
586 			break;
587 		}
588 
589 		buf = buf + cpy_len;
590 	} while (loops--);
591 	sdd->state &= ~RXBUSY;
592 
593 	return 0;
594 }
595 
596 static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
597 {
598 	void __iomem *regs = sdd->regs;
599 	u32 val;
600 
601 	/* Disable Clock */
602 	if (!sdd->port_conf->clk_from_cmu) {
603 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
604 		val &= ~S3C64XX_SPI_ENCLK_ENABLE;
605 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
606 	}
607 
608 	/* Set Polarity and Phase */
609 	val = readl(regs + S3C64XX_SPI_CH_CFG);
610 	val &= ~(S3C64XX_SPI_CH_SLAVE |
611 			S3C64XX_SPI_CPOL_L |
612 			S3C64XX_SPI_CPHA_B);
613 
614 	if (sdd->cur_mode & SPI_CPOL)
615 		val |= S3C64XX_SPI_CPOL_L;
616 
617 	if (sdd->cur_mode & SPI_CPHA)
618 		val |= S3C64XX_SPI_CPHA_B;
619 
620 	writel(val, regs + S3C64XX_SPI_CH_CFG);
621 
622 	/* Set Channel & DMA Mode */
623 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
624 	val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
625 			| S3C64XX_SPI_MODE_CH_TSZ_MASK);
626 
627 	switch (sdd->cur_bpw) {
628 	case 32:
629 		val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
630 		val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;
631 		break;
632 	case 16:
633 		val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
634 		val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;
635 		break;
636 	default:
637 		val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
638 		val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;
639 		break;
640 	}
641 
642 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
643 
644 	if (sdd->port_conf->clk_from_cmu) {
645 		/* The src_clk clock is divided internally by 2 */
646 		clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
647 	} else {
648 		/* Configure Clock */
649 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
650 		val &= ~S3C64XX_SPI_PSR_MASK;
651 		val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1)
652 				& S3C64XX_SPI_PSR_MASK);
653 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
654 
655 		/* Enable Clock */
656 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
657 		val |= S3C64XX_SPI_ENCLK_ENABLE;
658 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
659 	}
660 }
661 
662 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
663 
664 static int s3c64xx_spi_prepare_message(struct spi_master *master,
665 				       struct spi_message *msg)
666 {
667 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
668 	struct spi_device *spi = msg->spi;
669 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
670 
671 	/* Configure feedback delay */
672 	writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
673 
674 	return 0;
675 }
676 
677 static int s3c64xx_spi_transfer_one(struct spi_master *master,
678 				    struct spi_device *spi,
679 				    struct spi_transfer *xfer)
680 {
681 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
682 	int status;
683 	u32 speed;
684 	u8 bpw;
685 	unsigned long flags;
686 	int use_dma;
687 
688 	reinit_completion(&sdd->xfer_completion);
689 
690 	/* Only BPW and Speed may change across transfers */
691 	bpw = xfer->bits_per_word;
692 	speed = xfer->speed_hz;
693 
694 	if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
695 		sdd->cur_bpw = bpw;
696 		sdd->cur_speed = speed;
697 		sdd->cur_mode = spi->mode;
698 		s3c64xx_spi_config(sdd);
699 	}
700 
701 	/* Polling method for xfers not bigger than FIFO capacity */
702 	use_dma = 0;
703 	if (!is_polling(sdd) &&
704 	    (sdd->rx_dma.ch && sdd->tx_dma.ch &&
705 	     (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1))))
706 		use_dma = 1;
707 
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 	enable_datapath(sdd, spi, xfer, use_dma);
715 
716 	/* Start the signals */
717 	s3c64xx_spi_set_cs(spi, true);
718 
719 	spin_unlock_irqrestore(&sdd->lock, flags);
720 
721 	if (use_dma)
722 		status = wait_for_dma(sdd, xfer);
723 	else
724 		status = wait_for_pio(sdd, xfer);
725 
726 	if (status) {
727 		dev_err(&spi->dev, "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
728 			xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
729 			(sdd->state & RXBUSY) ? 'f' : 'p',
730 			(sdd->state & TXBUSY) ? 'f' : 'p',
731 			xfer->len);
732 
733 		if (use_dma) {
734 			if (xfer->tx_buf != NULL
735 			    && (sdd->state & TXBUSY))
736 				dmaengine_terminate_all(sdd->tx_dma.ch);
737 			if (xfer->rx_buf != NULL
738 			    && (sdd->state & RXBUSY))
739 				dmaengine_terminate_all(sdd->rx_dma.ch);
740 		}
741 	} else {
742 		flush_fifo(sdd);
743 	}
744 
745 	return status;
746 }
747 
748 static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
749 				struct spi_device *spi)
750 {
751 	struct s3c64xx_spi_csinfo *cs;
752 	struct device_node *slave_np, *data_np = NULL;
753 	u32 fb_delay = 0;
754 
755 	slave_np = spi->dev.of_node;
756 	if (!slave_np) {
757 		dev_err(&spi->dev, "device node not found\n");
758 		return ERR_PTR(-EINVAL);
759 	}
760 
761 	data_np = of_get_child_by_name(slave_np, "controller-data");
762 	if (!data_np) {
763 		dev_err(&spi->dev, "child node 'controller-data' not found\n");
764 		return ERR_PTR(-EINVAL);
765 	}
766 
767 	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
768 	if (!cs) {
769 		of_node_put(data_np);
770 		return ERR_PTR(-ENOMEM);
771 	}
772 
773 	of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
774 	cs->fb_delay = fb_delay;
775 	of_node_put(data_np);
776 	return cs;
777 }
778 
779 /*
780  * Here we only check the validity of requested configuration
781  * and save the configuration in a local data-structure.
782  * The controller is actually configured only just before we
783  * get a message to transfer.
784  */
785 static int s3c64xx_spi_setup(struct spi_device *spi)
786 {
787 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
788 	struct s3c64xx_spi_driver_data *sdd;
789 	struct s3c64xx_spi_info *sci;
790 	int err;
791 
792 	sdd = spi_master_get_devdata(spi->master);
793 	if (spi->dev.of_node) {
794 		cs = s3c64xx_get_slave_ctrldata(spi);
795 		spi->controller_data = cs;
796 	} else if (cs) {
797 		/* On non-DT platforms the SPI core will set spi->cs_gpio
798 		 * to -ENOENT. The GPIO pin used to drive the chip select
799 		 * is defined by using platform data so spi->cs_gpio value
800 		 * has to be override to have the proper GPIO pin number.
801 		 */
802 		spi->cs_gpio = cs->line;
803 	}
804 
805 	if (IS_ERR_OR_NULL(cs)) {
806 		dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
807 		return -ENODEV;
808 	}
809 
810 	if (!spi_get_ctldata(spi)) {
811 		if (gpio_is_valid(spi->cs_gpio)) {
812 			err = gpio_request_one(spi->cs_gpio, GPIOF_OUT_INIT_HIGH,
813 					       dev_name(&spi->dev));
814 			if (err) {
815 				dev_err(&spi->dev,
816 					"Failed to get /CS gpio [%d]: %d\n",
817 					spi->cs_gpio, err);
818 				goto err_gpio_req;
819 			}
820 		}
821 
822 		spi_set_ctldata(spi, cs);
823 	}
824 
825 	sci = sdd->cntrlr_info;
826 
827 	pm_runtime_get_sync(&sdd->pdev->dev);
828 
829 	/* Check if we can provide the requested rate */
830 	if (!sdd->port_conf->clk_from_cmu) {
831 		u32 psr, speed;
832 
833 		/* Max possible */
834 		speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1);
835 
836 		if (spi->max_speed_hz > speed)
837 			spi->max_speed_hz = speed;
838 
839 		psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1;
840 		psr &= S3C64XX_SPI_PSR_MASK;
841 		if (psr == S3C64XX_SPI_PSR_MASK)
842 			psr--;
843 
844 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
845 		if (spi->max_speed_hz < speed) {
846 			if (psr+1 < S3C64XX_SPI_PSR_MASK) {
847 				psr++;
848 			} else {
849 				err = -EINVAL;
850 				goto setup_exit;
851 			}
852 		}
853 
854 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
855 		if (spi->max_speed_hz >= speed) {
856 			spi->max_speed_hz = speed;
857 		} else {
858 			dev_err(&spi->dev, "Can't set %dHz transfer speed\n",
859 				spi->max_speed_hz);
860 			err = -EINVAL;
861 			goto setup_exit;
862 		}
863 	}
864 
865 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
866 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
867 	s3c64xx_spi_set_cs(spi, false);
868 
869 	return 0;
870 
871 setup_exit:
872 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
873 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
874 	/* setup() returns with device de-selected */
875 	s3c64xx_spi_set_cs(spi, false);
876 
877 	if (gpio_is_valid(spi->cs_gpio))
878 		gpio_free(spi->cs_gpio);
879 	spi_set_ctldata(spi, NULL);
880 
881 err_gpio_req:
882 	if (spi->dev.of_node)
883 		kfree(cs);
884 
885 	return err;
886 }
887 
888 static void s3c64xx_spi_cleanup(struct spi_device *spi)
889 {
890 	struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
891 
892 	if (gpio_is_valid(spi->cs_gpio)) {
893 		gpio_free(spi->cs_gpio);
894 		if (spi->dev.of_node)
895 			kfree(cs);
896 		else {
897 			/* On non-DT platforms, the SPI core sets
898 			 * spi->cs_gpio to -ENOENT and .setup()
899 			 * overrides it with the GPIO pin value
900 			 * passed using platform data.
901 			 */
902 			spi->cs_gpio = -ENOENT;
903 		}
904 	}
905 
906 	spi_set_ctldata(spi, NULL);
907 }
908 
909 static irqreturn_t s3c64xx_spi_irq(int irq, void *data)
910 {
911 	struct s3c64xx_spi_driver_data *sdd = data;
912 	struct spi_master *spi = sdd->master;
913 	unsigned int val, clr = 0;
914 
915 	val = readl(sdd->regs + S3C64XX_SPI_STATUS);
916 
917 	if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) {
918 		clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR;
919 		dev_err(&spi->dev, "RX overrun\n");
920 	}
921 	if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) {
922 		clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR;
923 		dev_err(&spi->dev, "RX underrun\n");
924 	}
925 	if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) {
926 		clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR;
927 		dev_err(&spi->dev, "TX overrun\n");
928 	}
929 	if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) {
930 		clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
931 		dev_err(&spi->dev, "TX underrun\n");
932 	}
933 
934 	/* Clear the pending irq by setting and then clearing it */
935 	writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR);
936 	writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR);
937 
938 	return IRQ_HANDLED;
939 }
940 
941 static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel)
942 {
943 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
944 	void __iomem *regs = sdd->regs;
945 	unsigned int val;
946 
947 	sdd->cur_speed = 0;
948 
949 	if (sci->no_cs)
950 		writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
951 	else if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
952 		writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
953 
954 	/* Disable Interrupts - we use Polling if not DMA mode */
955 	writel(0, regs + S3C64XX_SPI_INT_EN);
956 
957 	if (!sdd->port_conf->clk_from_cmu)
958 		writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
959 				regs + S3C64XX_SPI_CLK_CFG);
960 	writel(0, regs + S3C64XX_SPI_MODE_CFG);
961 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
962 
963 	/* Clear any irq pending bits, should set and clear the bits */
964 	val = S3C64XX_SPI_PND_RX_OVERRUN_CLR |
965 		S3C64XX_SPI_PND_RX_UNDERRUN_CLR |
966 		S3C64XX_SPI_PND_TX_OVERRUN_CLR |
967 		S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
968 	writel(val, regs + S3C64XX_SPI_PENDING_CLR);
969 	writel(0, regs + S3C64XX_SPI_PENDING_CLR);
970 
971 	writel(0, regs + S3C64XX_SPI_SWAP_CFG);
972 
973 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
974 	val &= ~S3C64XX_SPI_MODE_4BURST;
975 	val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
976 	val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
977 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
978 
979 	flush_fifo(sdd);
980 }
981 
982 #ifdef CONFIG_OF
983 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
984 {
985 	struct s3c64xx_spi_info *sci;
986 	u32 temp;
987 
988 	sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
989 	if (!sci)
990 		return ERR_PTR(-ENOMEM);
991 
992 	if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
993 		dev_warn(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
994 		sci->src_clk_nr = 0;
995 	} else {
996 		sci->src_clk_nr = temp;
997 	}
998 
999 	if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
1000 		dev_warn(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
1001 		sci->num_cs = 1;
1002 	} else {
1003 		sci->num_cs = temp;
1004 	}
1005 
1006 	sci->no_cs = of_property_read_bool(dev->of_node, "broken-cs");
1007 
1008 	return sci;
1009 }
1010 #else
1011 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1012 {
1013 	return dev_get_platdata(dev);
1014 }
1015 #endif
1016 
1017 static const struct of_device_id s3c64xx_spi_dt_match[];
1018 
1019 static inline struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
1020 						struct platform_device *pdev)
1021 {
1022 #ifdef CONFIG_OF
1023 	if (pdev->dev.of_node) {
1024 		const struct of_device_id *match;
1025 		match = of_match_node(s3c64xx_spi_dt_match, pdev->dev.of_node);
1026 		return (struct s3c64xx_spi_port_config *)match->data;
1027 	}
1028 #endif
1029 	return (struct s3c64xx_spi_port_config *)
1030 			 platform_get_device_id(pdev)->driver_data;
1031 }
1032 
1033 static int s3c64xx_spi_probe(struct platform_device *pdev)
1034 {
1035 	struct resource	*mem_res;
1036 	struct s3c64xx_spi_driver_data *sdd;
1037 	struct s3c64xx_spi_info *sci = dev_get_platdata(&pdev->dev);
1038 	struct spi_master *master;
1039 	int ret, irq;
1040 	char clk_name[16];
1041 
1042 	if (!sci && pdev->dev.of_node) {
1043 		sci = s3c64xx_spi_parse_dt(&pdev->dev);
1044 		if (IS_ERR(sci))
1045 			return PTR_ERR(sci);
1046 	}
1047 
1048 	if (!sci) {
1049 		dev_err(&pdev->dev, "platform_data missing!\n");
1050 		return -ENODEV;
1051 	}
1052 
1053 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1054 	if (mem_res == NULL) {
1055 		dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
1056 		return -ENXIO;
1057 	}
1058 
1059 	irq = platform_get_irq(pdev, 0);
1060 	if (irq < 0) {
1061 		dev_warn(&pdev->dev, "Failed to get IRQ: %d\n", irq);
1062 		return irq;
1063 	}
1064 
1065 	master = spi_alloc_master(&pdev->dev,
1066 				sizeof(struct s3c64xx_spi_driver_data));
1067 	if (master == NULL) {
1068 		dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
1069 		return -ENOMEM;
1070 	}
1071 
1072 	platform_set_drvdata(pdev, master);
1073 
1074 	sdd = spi_master_get_devdata(master);
1075 	sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
1076 	sdd->master = master;
1077 	sdd->cntrlr_info = sci;
1078 	sdd->pdev = pdev;
1079 	sdd->sfr_start = mem_res->start;
1080 	if (pdev->dev.of_node) {
1081 		ret = of_alias_get_id(pdev->dev.of_node, "spi");
1082 		if (ret < 0) {
1083 			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
1084 				ret);
1085 			goto err_deref_master;
1086 		}
1087 		sdd->port_id = ret;
1088 	} else {
1089 		sdd->port_id = pdev->id;
1090 	}
1091 
1092 	sdd->cur_bpw = 8;
1093 
1094 	if (!sdd->pdev->dev.of_node && (!sci->dma_tx || !sci->dma_rx)) {
1095 		dev_warn(&pdev->dev, "Unable to get SPI tx/rx DMA data. Switching to poll mode\n");
1096 		sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL;
1097 	}
1098 
1099 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
1100 	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
1101 
1102 	master->dev.of_node = pdev->dev.of_node;
1103 	master->bus_num = sdd->port_id;
1104 	master->setup = s3c64xx_spi_setup;
1105 	master->cleanup = s3c64xx_spi_cleanup;
1106 	master->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
1107 	master->prepare_message = s3c64xx_spi_prepare_message;
1108 	master->transfer_one = s3c64xx_spi_transfer_one;
1109 	master->unprepare_transfer_hardware = s3c64xx_spi_unprepare_transfer;
1110 	master->num_chipselect = sci->num_cs;
1111 	master->dma_alignment = 8;
1112 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
1113 					SPI_BPW_MASK(8);
1114 	/* the spi->mode bits understood by this driver: */
1115 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1116 	master->auto_runtime_pm = true;
1117 	if (!is_polling(sdd))
1118 		master->can_dma = s3c64xx_spi_can_dma;
1119 
1120 	sdd->regs = devm_ioremap_resource(&pdev->dev, mem_res);
1121 	if (IS_ERR(sdd->regs)) {
1122 		ret = PTR_ERR(sdd->regs);
1123 		goto err_deref_master;
1124 	}
1125 
1126 	if (sci->cfg_gpio && sci->cfg_gpio()) {
1127 		dev_err(&pdev->dev, "Unable to config gpio\n");
1128 		ret = -EBUSY;
1129 		goto err_deref_master;
1130 	}
1131 
1132 	/* Setup clocks */
1133 	sdd->clk = devm_clk_get(&pdev->dev, "spi");
1134 	if (IS_ERR(sdd->clk)) {
1135 		dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
1136 		ret = PTR_ERR(sdd->clk);
1137 		goto err_deref_master;
1138 	}
1139 
1140 	ret = clk_prepare_enable(sdd->clk);
1141 	if (ret) {
1142 		dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
1143 		goto err_deref_master;
1144 	}
1145 
1146 	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
1147 	sdd->src_clk = devm_clk_get(&pdev->dev, clk_name);
1148 	if (IS_ERR(sdd->src_clk)) {
1149 		dev_err(&pdev->dev,
1150 			"Unable to acquire clock '%s'\n", clk_name);
1151 		ret = PTR_ERR(sdd->src_clk);
1152 		goto err_disable_clk;
1153 	}
1154 
1155 	ret = clk_prepare_enable(sdd->src_clk);
1156 	if (ret) {
1157 		dev_err(&pdev->dev, "Couldn't enable clock '%s'\n", clk_name);
1158 		goto err_disable_clk;
1159 	}
1160 
1161 	if (sdd->port_conf->clk_ioclk) {
1162 		sdd->ioclk = devm_clk_get(&pdev->dev, "spi_ioclk");
1163 		if (IS_ERR(sdd->ioclk)) {
1164 			dev_err(&pdev->dev, "Unable to acquire 'ioclk'\n");
1165 			ret = PTR_ERR(sdd->ioclk);
1166 			goto err_disable_src_clk;
1167 		}
1168 
1169 		ret = clk_prepare_enable(sdd->ioclk);
1170 		if (ret) {
1171 			dev_err(&pdev->dev, "Couldn't enable clock 'ioclk'\n");
1172 			goto err_disable_src_clk;
1173 		}
1174 	}
1175 
1176 	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1177 	pm_runtime_use_autosuspend(&pdev->dev);
1178 	pm_runtime_set_active(&pdev->dev);
1179 	pm_runtime_enable(&pdev->dev);
1180 	pm_runtime_get_sync(&pdev->dev);
1181 
1182 	/* Setup Deufult Mode */
1183 	s3c64xx_spi_hwinit(sdd, sdd->port_id);
1184 
1185 	spin_lock_init(&sdd->lock);
1186 	init_completion(&sdd->xfer_completion);
1187 
1188 	ret = devm_request_irq(&pdev->dev, irq, s3c64xx_spi_irq, 0,
1189 				"spi-s3c64xx", sdd);
1190 	if (ret != 0) {
1191 		dev_err(&pdev->dev, "Failed to request IRQ %d: %d\n",
1192 			irq, ret);
1193 		goto err_pm_put;
1194 	}
1195 
1196 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1197 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1198 	       sdd->regs + S3C64XX_SPI_INT_EN);
1199 
1200 	ret = devm_spi_register_master(&pdev->dev, master);
1201 	if (ret != 0) {
1202 		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
1203 		goto err_pm_put;
1204 	}
1205 
1206 	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",
1207 					sdd->port_id, master->num_chipselect);
1208 	dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\tDMA=[Rx-%p, Tx-%p]\n",
1209 					mem_res, (FIFO_LVL_MASK(sdd) >> 1) + 1,
1210 					sci->dma_rx, sci->dma_tx);
1211 
1212 	pm_runtime_mark_last_busy(&pdev->dev);
1213 	pm_runtime_put_autosuspend(&pdev->dev);
1214 
1215 	return 0;
1216 
1217 err_pm_put:
1218 	pm_runtime_put_noidle(&pdev->dev);
1219 	pm_runtime_disable(&pdev->dev);
1220 	pm_runtime_set_suspended(&pdev->dev);
1221 
1222 	clk_disable_unprepare(sdd->ioclk);
1223 err_disable_src_clk:
1224 	clk_disable_unprepare(sdd->src_clk);
1225 err_disable_clk:
1226 	clk_disable_unprepare(sdd->clk);
1227 err_deref_master:
1228 	spi_master_put(master);
1229 
1230 	return ret;
1231 }
1232 
1233 static int s3c64xx_spi_remove(struct platform_device *pdev)
1234 {
1235 	struct spi_master *master = platform_get_drvdata(pdev);
1236 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1237 
1238 	pm_runtime_get_sync(&pdev->dev);
1239 
1240 	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
1241 
1242 	clk_disable_unprepare(sdd->ioclk);
1243 
1244 	clk_disable_unprepare(sdd->src_clk);
1245 
1246 	clk_disable_unprepare(sdd->clk);
1247 
1248 	pm_runtime_put_noidle(&pdev->dev);
1249 	pm_runtime_disable(&pdev->dev);
1250 	pm_runtime_set_suspended(&pdev->dev);
1251 
1252 	return 0;
1253 }
1254 
1255 #ifdef CONFIG_PM_SLEEP
1256 static int s3c64xx_spi_suspend(struct device *dev)
1257 {
1258 	struct spi_master *master = dev_get_drvdata(dev);
1259 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1260 
1261 	int ret = spi_master_suspend(master);
1262 	if (ret)
1263 		return ret;
1264 
1265 	ret = pm_runtime_force_suspend(dev);
1266 	if (ret < 0)
1267 		return ret;
1268 
1269 	sdd->cur_speed = 0; /* Output Clock is stopped */
1270 
1271 	return 0;
1272 }
1273 
1274 static int s3c64xx_spi_resume(struct device *dev)
1275 {
1276 	struct spi_master *master = dev_get_drvdata(dev);
1277 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1278 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1279 	int ret;
1280 
1281 	if (sci->cfg_gpio)
1282 		sci->cfg_gpio();
1283 
1284 	ret = pm_runtime_force_resume(dev);
1285 	if (ret < 0)
1286 		return ret;
1287 
1288 	s3c64xx_spi_hwinit(sdd, sdd->port_id);
1289 
1290 	return spi_master_resume(master);
1291 }
1292 #endif /* CONFIG_PM_SLEEP */
1293 
1294 #ifdef CONFIG_PM
1295 static int s3c64xx_spi_runtime_suspend(struct device *dev)
1296 {
1297 	struct spi_master *master = dev_get_drvdata(dev);
1298 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1299 
1300 	clk_disable_unprepare(sdd->clk);
1301 	clk_disable_unprepare(sdd->src_clk);
1302 	clk_disable_unprepare(sdd->ioclk);
1303 
1304 	return 0;
1305 }
1306 
1307 static int s3c64xx_spi_runtime_resume(struct device *dev)
1308 {
1309 	struct spi_master *master = dev_get_drvdata(dev);
1310 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1311 	int ret;
1312 
1313 	if (sdd->port_conf->clk_ioclk) {
1314 		ret = clk_prepare_enable(sdd->ioclk);
1315 		if (ret != 0)
1316 			return ret;
1317 	}
1318 
1319 	ret = clk_prepare_enable(sdd->src_clk);
1320 	if (ret != 0)
1321 		goto err_disable_ioclk;
1322 
1323 	ret = clk_prepare_enable(sdd->clk);
1324 	if (ret != 0)
1325 		goto err_disable_src_clk;
1326 
1327 	return 0;
1328 
1329 err_disable_src_clk:
1330 	clk_disable_unprepare(sdd->src_clk);
1331 err_disable_ioclk:
1332 	clk_disable_unprepare(sdd->ioclk);
1333 
1334 	return ret;
1335 }
1336 #endif /* CONFIG_PM */
1337 
1338 static const struct dev_pm_ops s3c64xx_spi_pm = {
1339 	SET_SYSTEM_SLEEP_PM_OPS(s3c64xx_spi_suspend, s3c64xx_spi_resume)
1340 	SET_RUNTIME_PM_OPS(s3c64xx_spi_runtime_suspend,
1341 			   s3c64xx_spi_runtime_resume, NULL)
1342 };
1343 
1344 static struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
1345 	.fifo_lvl_mask	= { 0x7f },
1346 	.rx_lvl_offset	= 13,
1347 	.tx_st_done	= 21,
1348 	.high_speed	= true,
1349 };
1350 
1351 static struct s3c64xx_spi_port_config s3c6410_spi_port_config = {
1352 	.fifo_lvl_mask	= { 0x7f, 0x7F },
1353 	.rx_lvl_offset	= 13,
1354 	.tx_st_done	= 21,
1355 };
1356 
1357 static struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
1358 	.fifo_lvl_mask	= { 0x1ff, 0x7F },
1359 	.rx_lvl_offset	= 15,
1360 	.tx_st_done	= 25,
1361 	.high_speed	= true,
1362 };
1363 
1364 static struct s3c64xx_spi_port_config exynos4_spi_port_config = {
1365 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F },
1366 	.rx_lvl_offset	= 15,
1367 	.tx_st_done	= 25,
1368 	.high_speed	= true,
1369 	.clk_from_cmu	= true,
1370 };
1371 
1372 static struct s3c64xx_spi_port_config exynos5440_spi_port_config = {
1373 	.fifo_lvl_mask	= { 0x1ff },
1374 	.rx_lvl_offset	= 15,
1375 	.tx_st_done	= 25,
1376 	.high_speed	= true,
1377 	.clk_from_cmu	= true,
1378 	.quirks		= S3C64XX_SPI_QUIRK_POLL,
1379 };
1380 
1381 static struct s3c64xx_spi_port_config exynos7_spi_port_config = {
1382 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},
1383 	.rx_lvl_offset	= 15,
1384 	.tx_st_done	= 25,
1385 	.high_speed	= true,
1386 	.clk_from_cmu	= true,
1387 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1388 };
1389 
1390 static struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
1391 	.fifo_lvl_mask	= { 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff},
1392 	.rx_lvl_offset	= 15,
1393 	.tx_st_done	= 25,
1394 	.high_speed	= true,
1395 	.clk_from_cmu	= true,
1396 	.clk_ioclk	= true,
1397 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1398 };
1399 
1400 static const struct platform_device_id s3c64xx_spi_driver_ids[] = {
1401 	{
1402 		.name		= "s3c2443-spi",
1403 		.driver_data	= (kernel_ulong_t)&s3c2443_spi_port_config,
1404 	}, {
1405 		.name		= "s3c6410-spi",
1406 		.driver_data	= (kernel_ulong_t)&s3c6410_spi_port_config,
1407 	},
1408 	{ },
1409 };
1410 
1411 static const struct of_device_id s3c64xx_spi_dt_match[] = {
1412 	{ .compatible = "samsung,s3c2443-spi",
1413 			.data = (void *)&s3c2443_spi_port_config,
1414 	},
1415 	{ .compatible = "samsung,s3c6410-spi",
1416 			.data = (void *)&s3c6410_spi_port_config,
1417 	},
1418 	{ .compatible = "samsung,s5pv210-spi",
1419 			.data = (void *)&s5pv210_spi_port_config,
1420 	},
1421 	{ .compatible = "samsung,exynos4210-spi",
1422 			.data = (void *)&exynos4_spi_port_config,
1423 	},
1424 	{ .compatible = "samsung,exynos5440-spi",
1425 			.data = (void *)&exynos5440_spi_port_config,
1426 	},
1427 	{ .compatible = "samsung,exynos7-spi",
1428 			.data = (void *)&exynos7_spi_port_config,
1429 	},
1430 	{ .compatible = "samsung,exynos5433-spi",
1431 			.data = (void *)&exynos5433_spi_port_config,
1432 	},
1433 	{ },
1434 };
1435 MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
1436 
1437 static struct platform_driver s3c64xx_spi_driver = {
1438 	.driver = {
1439 		.name	= "s3c64xx-spi",
1440 		.pm = &s3c64xx_spi_pm,
1441 		.of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
1442 	},
1443 	.probe = s3c64xx_spi_probe,
1444 	.remove = s3c64xx_spi_remove,
1445 	.id_table = s3c64xx_spi_driver_ids,
1446 };
1447 MODULE_ALIAS("platform:s3c64xx-spi");
1448 
1449 module_platform_driver(s3c64xx_spi_driver);
1450 
1451 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1452 MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1453 MODULE_LICENSE("GPL");
1454