xref: /openbmc/linux/drivers/spi/spi-s3c64xx.c (revision 9cfc5c90)
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 	unsigned int dmach;
137 };
138 
139 /**
140  * struct s3c64xx_spi_info - SPI Controller hardware info
141  * @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
142  * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
143  * @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
144  * @high_speed: True, if the controller supports HIGH_SPEED_EN bit.
145  * @clk_from_cmu: True, if the controller does not include a clock mux and
146  *	prescaler unit.
147  *
148  * The Samsung s3c64xx SPI controller are used on various Samsung SoC's but
149  * differ in some aspects such as the size of the fifo and spi bus clock
150  * setup. Such differences are specified to the driver using this structure
151  * which is provided as driver data to the driver.
152  */
153 struct s3c64xx_spi_port_config {
154 	int	fifo_lvl_mask[MAX_SPI_PORTS];
155 	int	rx_lvl_offset;
156 	int	tx_st_done;
157 	int	quirks;
158 	bool	high_speed;
159 	bool	clk_from_cmu;
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  * @master: Pointer to the SPI Protocol master.
167  * @cntrlr_info: Platform specific data for the controller this driver manages.
168  * @tgl_spi: Pointer to the last CS left untoggled by the cs_change hint.
169  * @lock: Controller specific lock.
170  * @state: Set of FLAGS to indicate status.
171  * @rx_dmach: Controller's DMA channel for Rx.
172  * @tx_dmach: Controller's DMA channel for Tx.
173  * @sfr_start: BUS address of SPI controller regs.
174  * @regs: Pointer to ioremap'ed controller registers.
175  * @irq: interrupt
176  * @xfer_completion: To indicate completion of xfer task.
177  * @cur_mode: Stores the active configuration of the controller.
178  * @cur_bpw: Stores the active bits per word settings.
179  * @cur_speed: Stores the active xfer clock speed.
180  */
181 struct s3c64xx_spi_driver_data {
182 	void __iomem                    *regs;
183 	struct clk                      *clk;
184 	struct clk                      *src_clk;
185 	struct platform_device          *pdev;
186 	struct spi_master               *master;
187 	struct s3c64xx_spi_info  *cntrlr_info;
188 	struct spi_device               *tgl_spi;
189 	spinlock_t                      lock;
190 	unsigned long                   sfr_start;
191 	struct completion               xfer_completion;
192 	unsigned                        state;
193 	unsigned                        cur_mode, cur_bpw;
194 	unsigned                        cur_speed;
195 	struct s3c64xx_spi_dma_data	rx_dma;
196 	struct s3c64xx_spi_dma_data	tx_dma;
197 	struct s3c64xx_spi_port_config	*port_conf;
198 	unsigned int			port_id;
199 };
200 
201 static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
202 {
203 	void __iomem *regs = sdd->regs;
204 	unsigned long loops;
205 	u32 val;
206 
207 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
208 
209 	val = readl(regs + S3C64XX_SPI_CH_CFG);
210 	val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON);
211 	writel(val, regs + S3C64XX_SPI_CH_CFG);
212 
213 	val = readl(regs + S3C64XX_SPI_CH_CFG);
214 	val |= S3C64XX_SPI_CH_SW_RST;
215 	val &= ~S3C64XX_SPI_CH_HS_EN;
216 	writel(val, regs + S3C64XX_SPI_CH_CFG);
217 
218 	/* Flush TxFIFO*/
219 	loops = msecs_to_loops(1);
220 	do {
221 		val = readl(regs + S3C64XX_SPI_STATUS);
222 	} while (TX_FIFO_LVL(val, sdd) && loops--);
223 
224 	if (loops == 0)
225 		dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n");
226 
227 	/* Flush RxFIFO*/
228 	loops = msecs_to_loops(1);
229 	do {
230 		val = readl(regs + S3C64XX_SPI_STATUS);
231 		if (RX_FIFO_LVL(val, sdd))
232 			readl(regs + S3C64XX_SPI_RX_DATA);
233 		else
234 			break;
235 	} while (loops--);
236 
237 	if (loops == 0)
238 		dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n");
239 
240 	val = readl(regs + S3C64XX_SPI_CH_CFG);
241 	val &= ~S3C64XX_SPI_CH_SW_RST;
242 	writel(val, regs + S3C64XX_SPI_CH_CFG);
243 
244 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
245 	val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
246 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
247 }
248 
249 static void s3c64xx_spi_dmacb(void *data)
250 {
251 	struct s3c64xx_spi_driver_data *sdd;
252 	struct s3c64xx_spi_dma_data *dma = data;
253 	unsigned long flags;
254 
255 	if (dma->direction == DMA_DEV_TO_MEM)
256 		sdd = container_of(data,
257 			struct s3c64xx_spi_driver_data, rx_dma);
258 	else
259 		sdd = container_of(data,
260 			struct s3c64xx_spi_driver_data, tx_dma);
261 
262 	spin_lock_irqsave(&sdd->lock, flags);
263 
264 	if (dma->direction == DMA_DEV_TO_MEM) {
265 		sdd->state &= ~RXBUSY;
266 		if (!(sdd->state & TXBUSY))
267 			complete(&sdd->xfer_completion);
268 	} else {
269 		sdd->state &= ~TXBUSY;
270 		if (!(sdd->state & RXBUSY))
271 			complete(&sdd->xfer_completion);
272 	}
273 
274 	spin_unlock_irqrestore(&sdd->lock, flags);
275 }
276 
277 static void prepare_dma(struct s3c64xx_spi_dma_data *dma,
278 			struct sg_table *sgt)
279 {
280 	struct s3c64xx_spi_driver_data *sdd;
281 	struct dma_slave_config config;
282 	struct dma_async_tx_descriptor *desc;
283 
284 	memset(&config, 0, sizeof(config));
285 
286 	if (dma->direction == DMA_DEV_TO_MEM) {
287 		sdd = container_of((void *)dma,
288 			struct s3c64xx_spi_driver_data, rx_dma);
289 		config.direction = dma->direction;
290 		config.src_addr = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
291 		config.src_addr_width = sdd->cur_bpw / 8;
292 		config.src_maxburst = 1;
293 		dmaengine_slave_config(dma->ch, &config);
294 	} else {
295 		sdd = container_of((void *)dma,
296 			struct s3c64xx_spi_driver_data, tx_dma);
297 		config.direction = dma->direction;
298 		config.dst_addr = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
299 		config.dst_addr_width = sdd->cur_bpw / 8;
300 		config.dst_maxburst = 1;
301 		dmaengine_slave_config(dma->ch, &config);
302 	}
303 
304 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
305 				       dma->direction, DMA_PREP_INTERRUPT);
306 
307 	desc->callback = s3c64xx_spi_dmacb;
308 	desc->callback_param = dma;
309 
310 	dmaengine_submit(desc);
311 	dma_async_issue_pending(dma->ch);
312 }
313 
314 static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
315 {
316 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
317 	dma_filter_fn filter = sdd->cntrlr_info->filter;
318 	struct device *dev = &sdd->pdev->dev;
319 	dma_cap_mask_t mask;
320 	int ret;
321 
322 	if (!is_polling(sdd)) {
323 		dma_cap_zero(mask);
324 		dma_cap_set(DMA_SLAVE, mask);
325 
326 		/* Acquire DMA channels */
327 		sdd->rx_dma.ch = dma_request_slave_channel_compat(mask, filter,
328 				   (void *)(long)sdd->rx_dma.dmach, dev, "rx");
329 		if (!sdd->rx_dma.ch) {
330 			dev_err(dev, "Failed to get RX DMA channel\n");
331 			ret = -EBUSY;
332 			goto out;
333 		}
334 		spi->dma_rx = sdd->rx_dma.ch;
335 
336 		sdd->tx_dma.ch = dma_request_slave_channel_compat(mask, filter,
337 				   (void *)(long)sdd->tx_dma.dmach, dev, "tx");
338 		if (!sdd->tx_dma.ch) {
339 			dev_err(dev, "Failed to get TX DMA channel\n");
340 			ret = -EBUSY;
341 			goto out_rx;
342 		}
343 		spi->dma_tx = sdd->tx_dma.ch;
344 	}
345 
346 	return 0;
347 
348 out_rx:
349 	dma_release_channel(sdd->rx_dma.ch);
350 out:
351 	return ret;
352 }
353 
354 static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
355 {
356 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
357 
358 	/* Free DMA channels */
359 	if (!is_polling(sdd)) {
360 		dma_release_channel(sdd->rx_dma.ch);
361 		dma_release_channel(sdd->tx_dma.ch);
362 	}
363 
364 	return 0;
365 }
366 
367 static bool s3c64xx_spi_can_dma(struct spi_master *master,
368 				struct spi_device *spi,
369 				struct spi_transfer *xfer)
370 {
371 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
372 
373 	return xfer->len > (FIFO_LVL_MASK(sdd) >> 1) + 1;
374 }
375 
376 static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
377 				struct spi_device *spi,
378 				struct spi_transfer *xfer, int dma_mode)
379 {
380 	void __iomem *regs = sdd->regs;
381 	u32 modecfg, chcfg;
382 
383 	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
384 	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
385 
386 	chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
387 	chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
388 
389 	if (dma_mode) {
390 		chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
391 	} else {
392 		/* Always shift in data in FIFO, even if xfer is Tx only,
393 		 * this helps setting PCKT_CNT value for generating clocks
394 		 * as exactly needed.
395 		 */
396 		chcfg |= S3C64XX_SPI_CH_RXCH_ON;
397 		writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
398 					| S3C64XX_SPI_PACKET_CNT_EN,
399 					regs + S3C64XX_SPI_PACKET_CNT);
400 	}
401 
402 	if (xfer->tx_buf != NULL) {
403 		sdd->state |= TXBUSY;
404 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
405 		if (dma_mode) {
406 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
407 			prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
408 		} else {
409 			switch (sdd->cur_bpw) {
410 			case 32:
411 				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
412 					xfer->tx_buf, xfer->len / 4);
413 				break;
414 			case 16:
415 				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
416 					xfer->tx_buf, xfer->len / 2);
417 				break;
418 			default:
419 				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
420 					xfer->tx_buf, xfer->len);
421 				break;
422 			}
423 		}
424 	}
425 
426 	if (xfer->rx_buf != NULL) {
427 		sdd->state |= RXBUSY;
428 
429 		if (sdd->port_conf->high_speed && sdd->cur_speed >= 30000000UL
430 					&& !(sdd->cur_mode & SPI_CPHA))
431 			chcfg |= S3C64XX_SPI_CH_HS_EN;
432 
433 		if (dma_mode) {
434 			modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
435 			chcfg |= S3C64XX_SPI_CH_RXCH_ON;
436 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
437 					| S3C64XX_SPI_PACKET_CNT_EN,
438 					regs + S3C64XX_SPI_PACKET_CNT);
439 			prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
440 		}
441 	}
442 
443 	writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
444 	writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
445 }
446 
447 static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
448 					int timeout_ms)
449 {
450 	void __iomem *regs = sdd->regs;
451 	unsigned long val = 1;
452 	u32 status;
453 
454 	/* max fifo depth available */
455 	u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
456 
457 	if (timeout_ms)
458 		val = msecs_to_loops(timeout_ms);
459 
460 	do {
461 		status = readl(regs + S3C64XX_SPI_STATUS);
462 	} while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
463 
464 	/* return the actual received data length */
465 	return RX_FIFO_LVL(status, sdd);
466 }
467 
468 static int wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
469 			struct spi_transfer *xfer)
470 {
471 	void __iomem *regs = sdd->regs;
472 	unsigned long val;
473 	u32 status;
474 	int ms;
475 
476 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
477 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
478 	ms += 10; /* some tolerance */
479 
480 	val = msecs_to_jiffies(ms) + 10;
481 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
482 
483 	/*
484 	 * If the previous xfer was completed within timeout, then
485 	 * proceed further else return -EIO.
486 	 * DmaTx returns after simply writing data in the FIFO,
487 	 * w/o waiting for real transmission on the bus to finish.
488 	 * DmaRx returns only after Dma read data from FIFO which
489 	 * needs bus transmission to finish, so we don't worry if
490 	 * Xfer involved Rx(with or without Tx).
491 	 */
492 	if (val && !xfer->rx_buf) {
493 		val = msecs_to_loops(10);
494 		status = readl(regs + S3C64XX_SPI_STATUS);
495 		while ((TX_FIFO_LVL(status, sdd)
496 			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
497 		       && --val) {
498 			cpu_relax();
499 			status = readl(regs + S3C64XX_SPI_STATUS);
500 		}
501 
502 	}
503 
504 	/* If timed out while checking rx/tx status return error */
505 	if (!val)
506 		return -EIO;
507 
508 	return 0;
509 }
510 
511 static int wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
512 			struct spi_transfer *xfer)
513 {
514 	void __iomem *regs = sdd->regs;
515 	unsigned long val;
516 	u32 status;
517 	int loops;
518 	u32 cpy_len;
519 	u8 *buf;
520 	int ms;
521 
522 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
523 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
524 	ms += 10; /* some tolerance */
525 
526 	val = msecs_to_loops(ms);
527 	do {
528 		status = readl(regs + S3C64XX_SPI_STATUS);
529 	} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
530 
531 
532 	/* If it was only Tx */
533 	if (!xfer->rx_buf) {
534 		sdd->state &= ~TXBUSY;
535 		return 0;
536 	}
537 
538 	/*
539 	 * If the receive length is bigger than the controller fifo
540 	 * size, calculate the loops and read the fifo as many times.
541 	 * loops = length / max fifo size (calculated by using the
542 	 * fifo mask).
543 	 * For any size less than the fifo size the below code is
544 	 * executed atleast once.
545 	 */
546 	loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
547 	buf = xfer->rx_buf;
548 	do {
549 		/* wait for data to be received in the fifo */
550 		cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
551 						       (loops ? ms : 0));
552 
553 		switch (sdd->cur_bpw) {
554 		case 32:
555 			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
556 				     buf, cpy_len / 4);
557 			break;
558 		case 16:
559 			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
560 				     buf, cpy_len / 2);
561 			break;
562 		default:
563 			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
564 				    buf, cpy_len);
565 			break;
566 		}
567 
568 		buf = buf + cpy_len;
569 	} while (loops--);
570 	sdd->state &= ~RXBUSY;
571 
572 	return 0;
573 }
574 
575 static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
576 {
577 	void __iomem *regs = sdd->regs;
578 	u32 val;
579 
580 	/* Disable Clock */
581 	if (sdd->port_conf->clk_from_cmu) {
582 		clk_disable_unprepare(sdd->src_clk);
583 	} else {
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 		/* Configure Clock */
627 		/* There is half-multiplier before the SPI */
628 		clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
629 		/* Enable Clock */
630 		clk_prepare_enable(sdd->src_clk);
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 
646 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
647 
648 static int s3c64xx_spi_prepare_message(struct spi_master *master,
649 				       struct spi_message *msg)
650 {
651 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
652 	struct spi_device *spi = msg->spi;
653 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
654 
655 	/* If Master's(controller) state differs from that needed by Slave */
656 	if (sdd->cur_speed != spi->max_speed_hz
657 			|| sdd->cur_mode != spi->mode
658 			|| sdd->cur_bpw != spi->bits_per_word) {
659 		sdd->cur_bpw = spi->bits_per_word;
660 		sdd->cur_speed = spi->max_speed_hz;
661 		sdd->cur_mode = spi->mode;
662 		s3c64xx_spi_config(sdd);
663 	}
664 
665 	/* Configure feedback delay */
666 	writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
667 
668 	return 0;
669 }
670 
671 static int s3c64xx_spi_transfer_one(struct spi_master *master,
672 				    struct spi_device *spi,
673 				    struct spi_transfer *xfer)
674 {
675 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
676 	int status;
677 	u32 speed;
678 	u8 bpw;
679 	unsigned long flags;
680 	int use_dma;
681 
682 	reinit_completion(&sdd->xfer_completion);
683 
684 	/* Only BPW and Speed may change across transfers */
685 	bpw = xfer->bits_per_word;
686 	speed = xfer->speed_hz;
687 
688 	if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
689 		sdd->cur_bpw = bpw;
690 		sdd->cur_speed = speed;
691 		s3c64xx_spi_config(sdd);
692 	}
693 
694 	/* Polling method for xfers not bigger than FIFO capacity */
695 	use_dma = 0;
696 	if (!is_polling(sdd) &&
697 	    (sdd->rx_dma.ch && sdd->tx_dma.ch &&
698 	     (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1))))
699 		use_dma = 1;
700 
701 	spin_lock_irqsave(&sdd->lock, flags);
702 
703 	/* Pending only which is to be done */
704 	sdd->state &= ~RXBUSY;
705 	sdd->state &= ~TXBUSY;
706 
707 	enable_datapath(sdd, spi, xfer, use_dma);
708 
709 	/* Start the signals */
710 	if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
711 		writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
712 	else
713 		writel(readl(sdd->regs + S3C64XX_SPI_SLAVE_SEL)
714 			| S3C64XX_SPI_SLAVE_AUTO | S3C64XX_SPI_SLAVE_NSC_CNT_2,
715 			sdd->regs + S3C64XX_SPI_SLAVE_SEL);
716 
717 	spin_unlock_irqrestore(&sdd->lock, flags);
718 
719 	if (use_dma)
720 		status = wait_for_dma(sdd, xfer);
721 	else
722 		status = wait_for_pio(sdd, xfer);
723 
724 	if (status) {
725 		dev_err(&spi->dev, "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
726 			xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
727 			(sdd->state & RXBUSY) ? 'f' : 'p',
728 			(sdd->state & TXBUSY) ? 'f' : 'p',
729 			xfer->len);
730 
731 		if (use_dma) {
732 			if (xfer->tx_buf != NULL
733 			    && (sdd->state & TXBUSY))
734 				dmaengine_terminate_all(sdd->tx_dma.ch);
735 			if (xfer->rx_buf != NULL
736 			    && (sdd->state & RXBUSY))
737 				dmaengine_terminate_all(sdd->rx_dma.ch);
738 		}
739 	} else {
740 		flush_fifo(sdd);
741 	}
742 
743 	return status;
744 }
745 
746 static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
747 				struct spi_device *spi)
748 {
749 	struct s3c64xx_spi_csinfo *cs;
750 	struct device_node *slave_np, *data_np = NULL;
751 	u32 fb_delay = 0;
752 
753 	slave_np = spi->dev.of_node;
754 	if (!slave_np) {
755 		dev_err(&spi->dev, "device node not found\n");
756 		return ERR_PTR(-EINVAL);
757 	}
758 
759 	data_np = of_get_child_by_name(slave_np, "controller-data");
760 	if (!data_np) {
761 		dev_err(&spi->dev, "child node 'controller-data' not found\n");
762 		return ERR_PTR(-EINVAL);
763 	}
764 
765 	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
766 	if (!cs) {
767 		of_node_put(data_np);
768 		return ERR_PTR(-ENOMEM);
769 	}
770 
771 	of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
772 	cs->fb_delay = fb_delay;
773 	of_node_put(data_np);
774 	return cs;
775 }
776 
777 /*
778  * Here we only check the validity of requested configuration
779  * and save the configuration in a local data-structure.
780  * The controller is actually configured only just before we
781  * get a message to transfer.
782  */
783 static int s3c64xx_spi_setup(struct spi_device *spi)
784 {
785 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
786 	struct s3c64xx_spi_driver_data *sdd;
787 	struct s3c64xx_spi_info *sci;
788 	int err;
789 
790 	sdd = spi_master_get_devdata(spi->master);
791 	if (spi->dev.of_node) {
792 		cs = s3c64xx_get_slave_ctrldata(spi);
793 		spi->controller_data = cs;
794 	} else if (cs) {
795 		/* On non-DT platforms the SPI core will set spi->cs_gpio
796 		 * to -ENOENT. The GPIO pin used to drive the chip select
797 		 * is defined by using platform data so spi->cs_gpio value
798 		 * has to be override to have the proper GPIO pin number.
799 		 */
800 		spi->cs_gpio = cs->line;
801 	}
802 
803 	if (IS_ERR_OR_NULL(cs)) {
804 		dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
805 		return -ENODEV;
806 	}
807 
808 	if (!spi_get_ctldata(spi)) {
809 		if (gpio_is_valid(spi->cs_gpio)) {
810 			err = gpio_request_one(spi->cs_gpio, GPIOF_OUT_INIT_HIGH,
811 					       dev_name(&spi->dev));
812 			if (err) {
813 				dev_err(&spi->dev,
814 					"Failed to get /CS gpio [%d]: %d\n",
815 					spi->cs_gpio, err);
816 				goto err_gpio_req;
817 			}
818 		}
819 
820 		spi_set_ctldata(spi, cs);
821 	}
822 
823 	sci = sdd->cntrlr_info;
824 
825 	pm_runtime_get_sync(&sdd->pdev->dev);
826 
827 	/* Check if we can provide the requested rate */
828 	if (!sdd->port_conf->clk_from_cmu) {
829 		u32 psr, speed;
830 
831 		/* Max possible */
832 		speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1);
833 
834 		if (spi->max_speed_hz > speed)
835 			spi->max_speed_hz = speed;
836 
837 		psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1;
838 		psr &= S3C64XX_SPI_PSR_MASK;
839 		if (psr == S3C64XX_SPI_PSR_MASK)
840 			psr--;
841 
842 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
843 		if (spi->max_speed_hz < speed) {
844 			if (psr+1 < S3C64XX_SPI_PSR_MASK) {
845 				psr++;
846 			} else {
847 				err = -EINVAL;
848 				goto setup_exit;
849 			}
850 		}
851 
852 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
853 		if (spi->max_speed_hz >= speed) {
854 			spi->max_speed_hz = speed;
855 		} else {
856 			dev_err(&spi->dev, "Can't set %dHz transfer speed\n",
857 				spi->max_speed_hz);
858 			err = -EINVAL;
859 			goto setup_exit;
860 		}
861 	}
862 
863 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
864 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
865 	if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
866 		writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
867 	return 0;
868 
869 setup_exit:
870 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
871 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
872 	/* setup() returns with device de-selected */
873 	if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
874 		writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
875 
876 	if (gpio_is_valid(spi->cs_gpio))
877 		gpio_free(spi->cs_gpio);
878 	spi_set_ctldata(spi, NULL);
879 
880 err_gpio_req:
881 	if (spi->dev.of_node)
882 		kfree(cs);
883 
884 	return err;
885 }
886 
887 static void s3c64xx_spi_cleanup(struct spi_device *spi)
888 {
889 	struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
890 
891 	if (gpio_is_valid(spi->cs_gpio)) {
892 		gpio_free(spi->cs_gpio);
893 		if (spi->dev.of_node)
894 			kfree(cs);
895 		else {
896 			/* On non-DT platforms, the SPI core sets
897 			 * spi->cs_gpio to -ENOENT and .setup()
898 			 * overrides it with the GPIO pin value
899 			 * passed using platform data.
900 			 */
901 			spi->cs_gpio = -ENOENT;
902 		}
903 	}
904 
905 	spi_set_ctldata(spi, NULL);
906 }
907 
908 static irqreturn_t s3c64xx_spi_irq(int irq, void *data)
909 {
910 	struct s3c64xx_spi_driver_data *sdd = data;
911 	struct spi_master *spi = sdd->master;
912 	unsigned int val, clr = 0;
913 
914 	val = readl(sdd->regs + S3C64XX_SPI_STATUS);
915 
916 	if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) {
917 		clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR;
918 		dev_err(&spi->dev, "RX overrun\n");
919 	}
920 	if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) {
921 		clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR;
922 		dev_err(&spi->dev, "RX underrun\n");
923 	}
924 	if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) {
925 		clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR;
926 		dev_err(&spi->dev, "TX overrun\n");
927 	}
928 	if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) {
929 		clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
930 		dev_err(&spi->dev, "TX underrun\n");
931 	}
932 
933 	/* Clear the pending irq by setting and then clearing it */
934 	writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR);
935 	writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR);
936 
937 	return IRQ_HANDLED;
938 }
939 
940 static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel)
941 {
942 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
943 	void __iomem *regs = sdd->regs;
944 	unsigned int val;
945 
946 	sdd->cur_speed = 0;
947 
948 	if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
949 		writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
950 
951 	/* Disable Interrupts - we use Polling if not DMA mode */
952 	writel(0, regs + S3C64XX_SPI_INT_EN);
953 
954 	if (!sdd->port_conf->clk_from_cmu)
955 		writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
956 				regs + S3C64XX_SPI_CLK_CFG);
957 	writel(0, regs + S3C64XX_SPI_MODE_CFG);
958 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
959 
960 	/* Clear any irq pending bits, should set and clear the bits */
961 	val = S3C64XX_SPI_PND_RX_OVERRUN_CLR |
962 		S3C64XX_SPI_PND_RX_UNDERRUN_CLR |
963 		S3C64XX_SPI_PND_TX_OVERRUN_CLR |
964 		S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
965 	writel(val, regs + S3C64XX_SPI_PENDING_CLR);
966 	writel(0, regs + S3C64XX_SPI_PENDING_CLR);
967 
968 	writel(0, regs + S3C64XX_SPI_SWAP_CFG);
969 
970 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
971 	val &= ~S3C64XX_SPI_MODE_4BURST;
972 	val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
973 	val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
974 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
975 
976 	flush_fifo(sdd);
977 }
978 
979 #ifdef CONFIG_OF
980 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
981 {
982 	struct s3c64xx_spi_info *sci;
983 	u32 temp;
984 
985 	sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
986 	if (!sci)
987 		return ERR_PTR(-ENOMEM);
988 
989 	if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
990 		dev_warn(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
991 		sci->src_clk_nr = 0;
992 	} else {
993 		sci->src_clk_nr = temp;
994 	}
995 
996 	if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
997 		dev_warn(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
998 		sci->num_cs = 1;
999 	} else {
1000 		sci->num_cs = temp;
1001 	}
1002 
1003 	return sci;
1004 }
1005 #else
1006 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1007 {
1008 	return dev_get_platdata(dev);
1009 }
1010 #endif
1011 
1012 static const struct of_device_id s3c64xx_spi_dt_match[];
1013 
1014 static inline struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
1015 						struct platform_device *pdev)
1016 {
1017 #ifdef CONFIG_OF
1018 	if (pdev->dev.of_node) {
1019 		const struct of_device_id *match;
1020 		match = of_match_node(s3c64xx_spi_dt_match, pdev->dev.of_node);
1021 		return (struct s3c64xx_spi_port_config *)match->data;
1022 	}
1023 #endif
1024 	return (struct s3c64xx_spi_port_config *)
1025 			 platform_get_device_id(pdev)->driver_data;
1026 }
1027 
1028 static int s3c64xx_spi_probe(struct platform_device *pdev)
1029 {
1030 	struct resource	*mem_res;
1031 	struct resource	*res;
1032 	struct s3c64xx_spi_driver_data *sdd;
1033 	struct s3c64xx_spi_info *sci = dev_get_platdata(&pdev->dev);
1034 	struct spi_master *master;
1035 	int ret, irq;
1036 	char clk_name[16];
1037 
1038 	if (!sci && pdev->dev.of_node) {
1039 		sci = s3c64xx_spi_parse_dt(&pdev->dev);
1040 		if (IS_ERR(sci))
1041 			return PTR_ERR(sci);
1042 	}
1043 
1044 	if (!sci) {
1045 		dev_err(&pdev->dev, "platform_data missing!\n");
1046 		return -ENODEV;
1047 	}
1048 
1049 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1050 	if (mem_res == NULL) {
1051 		dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
1052 		return -ENXIO;
1053 	}
1054 
1055 	irq = platform_get_irq(pdev, 0);
1056 	if (irq < 0) {
1057 		dev_warn(&pdev->dev, "Failed to get IRQ: %d\n", irq);
1058 		return irq;
1059 	}
1060 
1061 	master = spi_alloc_master(&pdev->dev,
1062 				sizeof(struct s3c64xx_spi_driver_data));
1063 	if (master == NULL) {
1064 		dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
1065 		return -ENOMEM;
1066 	}
1067 
1068 	platform_set_drvdata(pdev, master);
1069 
1070 	sdd = spi_master_get_devdata(master);
1071 	sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
1072 	sdd->master = master;
1073 	sdd->cntrlr_info = sci;
1074 	sdd->pdev = pdev;
1075 	sdd->sfr_start = mem_res->start;
1076 	if (pdev->dev.of_node) {
1077 		ret = of_alias_get_id(pdev->dev.of_node, "spi");
1078 		if (ret < 0) {
1079 			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
1080 				ret);
1081 			goto err0;
1082 		}
1083 		sdd->port_id = ret;
1084 	} else {
1085 		sdd->port_id = pdev->id;
1086 	}
1087 
1088 	sdd->cur_bpw = 8;
1089 
1090 	if (!sdd->pdev->dev.of_node) {
1091 		res = platform_get_resource(pdev, IORESOURCE_DMA,  0);
1092 		if (!res) {
1093 			dev_warn(&pdev->dev, "Unable to get SPI tx dma resource. Switching to poll mode\n");
1094 			sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL;
1095 		} else
1096 			sdd->tx_dma.dmach = res->start;
1097 
1098 		res = platform_get_resource(pdev, IORESOURCE_DMA,  1);
1099 		if (!res) {
1100 			dev_warn(&pdev->dev, "Unable to get SPI rx dma resource. Switching to poll mode\n");
1101 			sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL;
1102 		} else
1103 			sdd->rx_dma.dmach = res->start;
1104 	}
1105 
1106 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
1107 	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
1108 
1109 	master->dev.of_node = pdev->dev.of_node;
1110 	master->bus_num = sdd->port_id;
1111 	master->setup = s3c64xx_spi_setup;
1112 	master->cleanup = s3c64xx_spi_cleanup;
1113 	master->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
1114 	master->prepare_message = s3c64xx_spi_prepare_message;
1115 	master->transfer_one = s3c64xx_spi_transfer_one;
1116 	master->unprepare_transfer_hardware = s3c64xx_spi_unprepare_transfer;
1117 	master->num_chipselect = sci->num_cs;
1118 	master->dma_alignment = 8;
1119 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
1120 					SPI_BPW_MASK(8);
1121 	/* the spi->mode bits understood by this driver: */
1122 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1123 	master->auto_runtime_pm = true;
1124 	if (!is_polling(sdd))
1125 		master->can_dma = s3c64xx_spi_can_dma;
1126 
1127 	sdd->regs = devm_ioremap_resource(&pdev->dev, mem_res);
1128 	if (IS_ERR(sdd->regs)) {
1129 		ret = PTR_ERR(sdd->regs);
1130 		goto err0;
1131 	}
1132 
1133 	if (sci->cfg_gpio && sci->cfg_gpio()) {
1134 		dev_err(&pdev->dev, "Unable to config gpio\n");
1135 		ret = -EBUSY;
1136 		goto err0;
1137 	}
1138 
1139 	/* Setup clocks */
1140 	sdd->clk = devm_clk_get(&pdev->dev, "spi");
1141 	if (IS_ERR(sdd->clk)) {
1142 		dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
1143 		ret = PTR_ERR(sdd->clk);
1144 		goto err0;
1145 	}
1146 
1147 	if (clk_prepare_enable(sdd->clk)) {
1148 		dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
1149 		ret = -EBUSY;
1150 		goto err0;
1151 	}
1152 
1153 	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
1154 	sdd->src_clk = devm_clk_get(&pdev->dev, clk_name);
1155 	if (IS_ERR(sdd->src_clk)) {
1156 		dev_err(&pdev->dev,
1157 			"Unable to acquire clock '%s'\n", clk_name);
1158 		ret = PTR_ERR(sdd->src_clk);
1159 		goto err2;
1160 	}
1161 
1162 	if (clk_prepare_enable(sdd->src_clk)) {
1163 		dev_err(&pdev->dev, "Couldn't enable clock '%s'\n", clk_name);
1164 		ret = -EBUSY;
1165 		goto err2;
1166 	}
1167 
1168 	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1169 	pm_runtime_use_autosuspend(&pdev->dev);
1170 	pm_runtime_set_active(&pdev->dev);
1171 	pm_runtime_enable(&pdev->dev);
1172 	pm_runtime_get_sync(&pdev->dev);
1173 
1174 	/* Setup Deufult Mode */
1175 	s3c64xx_spi_hwinit(sdd, sdd->port_id);
1176 
1177 	spin_lock_init(&sdd->lock);
1178 	init_completion(&sdd->xfer_completion);
1179 
1180 	ret = devm_request_irq(&pdev->dev, irq, s3c64xx_spi_irq, 0,
1181 				"spi-s3c64xx", sdd);
1182 	if (ret != 0) {
1183 		dev_err(&pdev->dev, "Failed to request IRQ %d: %d\n",
1184 			irq, ret);
1185 		goto err3;
1186 	}
1187 
1188 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1189 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1190 	       sdd->regs + S3C64XX_SPI_INT_EN);
1191 
1192 	ret = devm_spi_register_master(&pdev->dev, master);
1193 	if (ret != 0) {
1194 		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
1195 		goto err3;
1196 	}
1197 
1198 	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",
1199 					sdd->port_id, master->num_chipselect);
1200 	dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\tDMA=[Rx-%d, Tx-%d]\n",
1201 					mem_res, (FIFO_LVL_MASK(sdd) >> 1) + 1,
1202 					sdd->rx_dma.dmach, sdd->tx_dma.dmach);
1203 
1204 	pm_runtime_mark_last_busy(&pdev->dev);
1205 	pm_runtime_put_autosuspend(&pdev->dev);
1206 
1207 	return 0;
1208 
1209 err3:
1210 	pm_runtime_put_noidle(&pdev->dev);
1211 	pm_runtime_disable(&pdev->dev);
1212 	pm_runtime_set_suspended(&pdev->dev);
1213 
1214 	clk_disable_unprepare(sdd->src_clk);
1215 err2:
1216 	clk_disable_unprepare(sdd->clk);
1217 err0:
1218 	spi_master_put(master);
1219 
1220 	return ret;
1221 }
1222 
1223 static int s3c64xx_spi_remove(struct platform_device *pdev)
1224 {
1225 	struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
1226 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1227 
1228 	pm_runtime_get_sync(&pdev->dev);
1229 
1230 	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
1231 
1232 	clk_disable_unprepare(sdd->src_clk);
1233 
1234 	clk_disable_unprepare(sdd->clk);
1235 
1236 	pm_runtime_put_noidle(&pdev->dev);
1237 	pm_runtime_disable(&pdev->dev);
1238 	pm_runtime_set_suspended(&pdev->dev);
1239 
1240 	return 0;
1241 }
1242 
1243 #ifdef CONFIG_PM_SLEEP
1244 static int s3c64xx_spi_suspend(struct device *dev)
1245 {
1246 	struct spi_master *master = dev_get_drvdata(dev);
1247 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1248 
1249 	int ret = spi_master_suspend(master);
1250 	if (ret)
1251 		return ret;
1252 
1253 	ret = pm_runtime_force_suspend(dev);
1254 	if (ret < 0)
1255 		return ret;
1256 
1257 	sdd->cur_speed = 0; /* Output Clock is stopped */
1258 
1259 	return 0;
1260 }
1261 
1262 static int s3c64xx_spi_resume(struct device *dev)
1263 {
1264 	struct spi_master *master = dev_get_drvdata(dev);
1265 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1266 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1267 	int ret;
1268 
1269 	if (sci->cfg_gpio)
1270 		sci->cfg_gpio();
1271 
1272 	ret = pm_runtime_force_resume(dev);
1273 	if (ret < 0)
1274 		return ret;
1275 
1276 	s3c64xx_spi_hwinit(sdd, sdd->port_id);
1277 
1278 	return spi_master_resume(master);
1279 }
1280 #endif /* CONFIG_PM_SLEEP */
1281 
1282 #ifdef CONFIG_PM
1283 static int s3c64xx_spi_runtime_suspend(struct device *dev)
1284 {
1285 	struct spi_master *master = dev_get_drvdata(dev);
1286 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1287 
1288 	clk_disable_unprepare(sdd->clk);
1289 	clk_disable_unprepare(sdd->src_clk);
1290 
1291 	return 0;
1292 }
1293 
1294 static int s3c64xx_spi_runtime_resume(struct device *dev)
1295 {
1296 	struct spi_master *master = dev_get_drvdata(dev);
1297 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1298 	int ret;
1299 
1300 	ret = clk_prepare_enable(sdd->src_clk);
1301 	if (ret != 0)
1302 		return ret;
1303 
1304 	ret = clk_prepare_enable(sdd->clk);
1305 	if (ret != 0) {
1306 		clk_disable_unprepare(sdd->src_clk);
1307 		return ret;
1308 	}
1309 
1310 	return 0;
1311 }
1312 #endif /* CONFIG_PM */
1313 
1314 static const struct dev_pm_ops s3c64xx_spi_pm = {
1315 	SET_SYSTEM_SLEEP_PM_OPS(s3c64xx_spi_suspend, s3c64xx_spi_resume)
1316 	SET_RUNTIME_PM_OPS(s3c64xx_spi_runtime_suspend,
1317 			   s3c64xx_spi_runtime_resume, NULL)
1318 };
1319 
1320 static struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
1321 	.fifo_lvl_mask	= { 0x7f },
1322 	.rx_lvl_offset	= 13,
1323 	.tx_st_done	= 21,
1324 	.high_speed	= true,
1325 };
1326 
1327 static struct s3c64xx_spi_port_config s3c6410_spi_port_config = {
1328 	.fifo_lvl_mask	= { 0x7f, 0x7F },
1329 	.rx_lvl_offset	= 13,
1330 	.tx_st_done	= 21,
1331 };
1332 
1333 static struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
1334 	.fifo_lvl_mask	= { 0x1ff, 0x7F },
1335 	.rx_lvl_offset	= 15,
1336 	.tx_st_done	= 25,
1337 	.high_speed	= true,
1338 };
1339 
1340 static struct s3c64xx_spi_port_config exynos4_spi_port_config = {
1341 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F },
1342 	.rx_lvl_offset	= 15,
1343 	.tx_st_done	= 25,
1344 	.high_speed	= true,
1345 	.clk_from_cmu	= true,
1346 };
1347 
1348 static struct s3c64xx_spi_port_config exynos5440_spi_port_config = {
1349 	.fifo_lvl_mask	= { 0x1ff },
1350 	.rx_lvl_offset	= 15,
1351 	.tx_st_done	= 25,
1352 	.high_speed	= true,
1353 	.clk_from_cmu	= true,
1354 	.quirks		= S3C64XX_SPI_QUIRK_POLL,
1355 };
1356 
1357 static struct s3c64xx_spi_port_config exynos7_spi_port_config = {
1358 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},
1359 	.rx_lvl_offset	= 15,
1360 	.tx_st_done	= 25,
1361 	.high_speed	= true,
1362 	.clk_from_cmu	= true,
1363 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1364 };
1365 
1366 static const struct platform_device_id s3c64xx_spi_driver_ids[] = {
1367 	{
1368 		.name		= "s3c2443-spi",
1369 		.driver_data	= (kernel_ulong_t)&s3c2443_spi_port_config,
1370 	}, {
1371 		.name		= "s3c6410-spi",
1372 		.driver_data	= (kernel_ulong_t)&s3c6410_spi_port_config,
1373 	}, {
1374 		.name		= "s5pv210-spi",
1375 		.driver_data	= (kernel_ulong_t)&s5pv210_spi_port_config,
1376 	}, {
1377 		.name		= "exynos4210-spi",
1378 		.driver_data	= (kernel_ulong_t)&exynos4_spi_port_config,
1379 	},
1380 	{ },
1381 };
1382 
1383 static const struct of_device_id s3c64xx_spi_dt_match[] = {
1384 	{ .compatible = "samsung,s3c2443-spi",
1385 			.data = (void *)&s3c2443_spi_port_config,
1386 	},
1387 	{ .compatible = "samsung,s3c6410-spi",
1388 			.data = (void *)&s3c6410_spi_port_config,
1389 	},
1390 	{ .compatible = "samsung,s5pv210-spi",
1391 			.data = (void *)&s5pv210_spi_port_config,
1392 	},
1393 	{ .compatible = "samsung,exynos4210-spi",
1394 			.data = (void *)&exynos4_spi_port_config,
1395 	},
1396 	{ .compatible = "samsung,exynos5440-spi",
1397 			.data = (void *)&exynos5440_spi_port_config,
1398 	},
1399 	{ .compatible = "samsung,exynos7-spi",
1400 			.data = (void *)&exynos7_spi_port_config,
1401 	},
1402 	{ },
1403 };
1404 MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
1405 
1406 static struct platform_driver s3c64xx_spi_driver = {
1407 	.driver = {
1408 		.name	= "s3c64xx-spi",
1409 		.pm = &s3c64xx_spi_pm,
1410 		.of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
1411 	},
1412 	.probe = s3c64xx_spi_probe,
1413 	.remove = s3c64xx_spi_remove,
1414 	.id_table = s3c64xx_spi_driver_ids,
1415 };
1416 MODULE_ALIAS("platform:s3c64xx-spi");
1417 
1418 module_platform_driver(s3c64xx_spi_driver);
1419 
1420 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1421 MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1422 MODULE_LICENSE("GPL");
1423