xref: /openbmc/linux/drivers/spi/spi-s3c64xx.c (revision 65417d9f)
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 
345 	if (is_polling(sdd))
346 		return 0;
347 
348 	spi->dma_rx = sdd->rx_dma.ch;
349 	spi->dma_tx = sdd->tx_dma.ch;
350 
351 	return 0;
352 }
353 
354 static bool s3c64xx_spi_can_dma(struct spi_master *master,
355 				struct spi_device *spi,
356 				struct spi_transfer *xfer)
357 {
358 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
359 
360 	return xfer->len > (FIFO_LVL_MASK(sdd) >> 1) + 1;
361 }
362 
363 static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
364 				struct spi_device *spi,
365 				struct spi_transfer *xfer, int dma_mode)
366 {
367 	void __iomem *regs = sdd->regs;
368 	u32 modecfg, chcfg;
369 
370 	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
371 	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
372 
373 	chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
374 	chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
375 
376 	if (dma_mode) {
377 		chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
378 	} else {
379 		/* Always shift in data in FIFO, even if xfer is Tx only,
380 		 * this helps setting PCKT_CNT value for generating clocks
381 		 * as exactly needed.
382 		 */
383 		chcfg |= S3C64XX_SPI_CH_RXCH_ON;
384 		writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
385 					| S3C64XX_SPI_PACKET_CNT_EN,
386 					regs + S3C64XX_SPI_PACKET_CNT);
387 	}
388 
389 	if (xfer->tx_buf != NULL) {
390 		sdd->state |= TXBUSY;
391 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
392 		if (dma_mode) {
393 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
394 			prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
395 		} else {
396 			switch (sdd->cur_bpw) {
397 			case 32:
398 				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
399 					xfer->tx_buf, xfer->len / 4);
400 				break;
401 			case 16:
402 				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
403 					xfer->tx_buf, xfer->len / 2);
404 				break;
405 			default:
406 				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
407 					xfer->tx_buf, xfer->len);
408 				break;
409 			}
410 		}
411 	}
412 
413 	if (xfer->rx_buf != NULL) {
414 		sdd->state |= RXBUSY;
415 
416 		if (sdd->port_conf->high_speed && sdd->cur_speed >= 30000000UL
417 					&& !(sdd->cur_mode & SPI_CPHA))
418 			chcfg |= S3C64XX_SPI_CH_HS_EN;
419 
420 		if (dma_mode) {
421 			modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
422 			chcfg |= S3C64XX_SPI_CH_RXCH_ON;
423 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
424 					| S3C64XX_SPI_PACKET_CNT_EN,
425 					regs + S3C64XX_SPI_PACKET_CNT);
426 			prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
427 		}
428 	}
429 
430 	writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
431 	writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
432 }
433 
434 static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
435 					int timeout_ms)
436 {
437 	void __iomem *regs = sdd->regs;
438 	unsigned long val = 1;
439 	u32 status;
440 
441 	/* max fifo depth available */
442 	u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
443 
444 	if (timeout_ms)
445 		val = msecs_to_loops(timeout_ms);
446 
447 	do {
448 		status = readl(regs + S3C64XX_SPI_STATUS);
449 	} while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
450 
451 	/* return the actual received data length */
452 	return RX_FIFO_LVL(status, sdd);
453 }
454 
455 static int wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
456 			struct spi_transfer *xfer)
457 {
458 	void __iomem *regs = sdd->regs;
459 	unsigned long val;
460 	u32 status;
461 	int ms;
462 
463 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
464 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
465 	ms += 10; /* some tolerance */
466 
467 	val = msecs_to_jiffies(ms) + 10;
468 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
469 
470 	/*
471 	 * If the previous xfer was completed within timeout, then
472 	 * proceed further else return -EIO.
473 	 * DmaTx returns after simply writing data in the FIFO,
474 	 * w/o waiting for real transmission on the bus to finish.
475 	 * DmaRx returns only after Dma read data from FIFO which
476 	 * needs bus transmission to finish, so we don't worry if
477 	 * Xfer involved Rx(with or without Tx).
478 	 */
479 	if (val && !xfer->rx_buf) {
480 		val = msecs_to_loops(10);
481 		status = readl(regs + S3C64XX_SPI_STATUS);
482 		while ((TX_FIFO_LVL(status, sdd)
483 			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
484 		       && --val) {
485 			cpu_relax();
486 			status = readl(regs + S3C64XX_SPI_STATUS);
487 		}
488 
489 	}
490 
491 	/* If timed out while checking rx/tx status return error */
492 	if (!val)
493 		return -EIO;
494 
495 	return 0;
496 }
497 
498 static int wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
499 			struct spi_transfer *xfer)
500 {
501 	void __iomem *regs = sdd->regs;
502 	unsigned long val;
503 	u32 status;
504 	int loops;
505 	u32 cpy_len;
506 	u8 *buf;
507 	int ms;
508 
509 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
510 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
511 	ms += 10; /* some tolerance */
512 
513 	val = msecs_to_loops(ms);
514 	do {
515 		status = readl(regs + S3C64XX_SPI_STATUS);
516 	} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
517 
518 
519 	/* If it was only Tx */
520 	if (!xfer->rx_buf) {
521 		sdd->state &= ~TXBUSY;
522 		return 0;
523 	}
524 
525 	/*
526 	 * If the receive length is bigger than the controller fifo
527 	 * size, calculate the loops and read the fifo as many times.
528 	 * loops = length / max fifo size (calculated by using the
529 	 * fifo mask).
530 	 * For any size less than the fifo size the below code is
531 	 * executed atleast once.
532 	 */
533 	loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
534 	buf = xfer->rx_buf;
535 	do {
536 		/* wait for data to be received in the fifo */
537 		cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
538 						       (loops ? ms : 0));
539 
540 		switch (sdd->cur_bpw) {
541 		case 32:
542 			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
543 				     buf, cpy_len / 4);
544 			break;
545 		case 16:
546 			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
547 				     buf, cpy_len / 2);
548 			break;
549 		default:
550 			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
551 				    buf, cpy_len);
552 			break;
553 		}
554 
555 		buf = buf + cpy_len;
556 	} while (loops--);
557 	sdd->state &= ~RXBUSY;
558 
559 	return 0;
560 }
561 
562 static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
563 {
564 	void __iomem *regs = sdd->regs;
565 	u32 val;
566 
567 	/* Disable Clock */
568 	if (!sdd->port_conf->clk_from_cmu) {
569 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
570 		val &= ~S3C64XX_SPI_ENCLK_ENABLE;
571 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
572 	}
573 
574 	/* Set Polarity and Phase */
575 	val = readl(regs + S3C64XX_SPI_CH_CFG);
576 	val &= ~(S3C64XX_SPI_CH_SLAVE |
577 			S3C64XX_SPI_CPOL_L |
578 			S3C64XX_SPI_CPHA_B);
579 
580 	if (sdd->cur_mode & SPI_CPOL)
581 		val |= S3C64XX_SPI_CPOL_L;
582 
583 	if (sdd->cur_mode & SPI_CPHA)
584 		val |= S3C64XX_SPI_CPHA_B;
585 
586 	writel(val, regs + S3C64XX_SPI_CH_CFG);
587 
588 	/* Set Channel & DMA Mode */
589 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
590 	val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
591 			| S3C64XX_SPI_MODE_CH_TSZ_MASK);
592 
593 	switch (sdd->cur_bpw) {
594 	case 32:
595 		val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
596 		val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;
597 		break;
598 	case 16:
599 		val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
600 		val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;
601 		break;
602 	default:
603 		val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
604 		val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;
605 		break;
606 	}
607 
608 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
609 
610 	if (sdd->port_conf->clk_from_cmu) {
611 		/* The src_clk clock is divided internally by 2 */
612 		clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
613 	} else {
614 		/* Configure Clock */
615 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
616 		val &= ~S3C64XX_SPI_PSR_MASK;
617 		val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1)
618 				& S3C64XX_SPI_PSR_MASK);
619 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
620 
621 		/* Enable Clock */
622 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
623 		val |= S3C64XX_SPI_ENCLK_ENABLE;
624 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
625 	}
626 }
627 
628 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
629 
630 static int s3c64xx_spi_prepare_message(struct spi_master *master,
631 				       struct spi_message *msg)
632 {
633 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
634 	struct spi_device *spi = msg->spi;
635 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
636 
637 	/* Configure feedback delay */
638 	writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
639 
640 	return 0;
641 }
642 
643 static int s3c64xx_spi_transfer_one(struct spi_master *master,
644 				    struct spi_device *spi,
645 				    struct spi_transfer *xfer)
646 {
647 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
648 	int status;
649 	u32 speed;
650 	u8 bpw;
651 	unsigned long flags;
652 	int use_dma;
653 
654 	reinit_completion(&sdd->xfer_completion);
655 
656 	/* Only BPW and Speed may change across transfers */
657 	bpw = xfer->bits_per_word;
658 	speed = xfer->speed_hz;
659 
660 	if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
661 		sdd->cur_bpw = bpw;
662 		sdd->cur_speed = speed;
663 		sdd->cur_mode = spi->mode;
664 		s3c64xx_spi_config(sdd);
665 	}
666 
667 	/* Polling method for xfers not bigger than FIFO capacity */
668 	use_dma = 0;
669 	if (!is_polling(sdd) &&
670 	    (sdd->rx_dma.ch && sdd->tx_dma.ch &&
671 	     (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1))))
672 		use_dma = 1;
673 
674 	spin_lock_irqsave(&sdd->lock, flags);
675 
676 	/* Pending only which is to be done */
677 	sdd->state &= ~RXBUSY;
678 	sdd->state &= ~TXBUSY;
679 
680 	enable_datapath(sdd, spi, xfer, use_dma);
681 
682 	/* Start the signals */
683 	s3c64xx_spi_set_cs(spi, true);
684 
685 	spin_unlock_irqrestore(&sdd->lock, flags);
686 
687 	if (use_dma)
688 		status = wait_for_dma(sdd, xfer);
689 	else
690 		status = wait_for_pio(sdd, xfer);
691 
692 	if (status) {
693 		dev_err(&spi->dev, "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
694 			xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
695 			(sdd->state & RXBUSY) ? 'f' : 'p',
696 			(sdd->state & TXBUSY) ? 'f' : 'p',
697 			xfer->len);
698 
699 		if (use_dma) {
700 			if (xfer->tx_buf != NULL
701 			    && (sdd->state & TXBUSY))
702 				dmaengine_terminate_all(sdd->tx_dma.ch);
703 			if (xfer->rx_buf != NULL
704 			    && (sdd->state & RXBUSY))
705 				dmaengine_terminate_all(sdd->rx_dma.ch);
706 		}
707 	} else {
708 		flush_fifo(sdd);
709 	}
710 
711 	return status;
712 }
713 
714 static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
715 				struct spi_device *spi)
716 {
717 	struct s3c64xx_spi_csinfo *cs;
718 	struct device_node *slave_np, *data_np = NULL;
719 	u32 fb_delay = 0;
720 
721 	slave_np = spi->dev.of_node;
722 	if (!slave_np) {
723 		dev_err(&spi->dev, "device node not found\n");
724 		return ERR_PTR(-EINVAL);
725 	}
726 
727 	data_np = of_get_child_by_name(slave_np, "controller-data");
728 	if (!data_np) {
729 		dev_err(&spi->dev, "child node 'controller-data' not found\n");
730 		return ERR_PTR(-EINVAL);
731 	}
732 
733 	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
734 	if (!cs) {
735 		of_node_put(data_np);
736 		return ERR_PTR(-ENOMEM);
737 	}
738 
739 	of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
740 	cs->fb_delay = fb_delay;
741 	of_node_put(data_np);
742 	return cs;
743 }
744 
745 /*
746  * Here we only check the validity of requested configuration
747  * and save the configuration in a local data-structure.
748  * The controller is actually configured only just before we
749  * get a message to transfer.
750  */
751 static int s3c64xx_spi_setup(struct spi_device *spi)
752 {
753 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
754 	struct s3c64xx_spi_driver_data *sdd;
755 	int err;
756 
757 	sdd = spi_master_get_devdata(spi->master);
758 	if (spi->dev.of_node) {
759 		cs = s3c64xx_get_slave_ctrldata(spi);
760 		spi->controller_data = cs;
761 	} else if (cs) {
762 		/* On non-DT platforms the SPI core will set spi->cs_gpio
763 		 * to -ENOENT. The GPIO pin used to drive the chip select
764 		 * is defined by using platform data so spi->cs_gpio value
765 		 * has to be override to have the proper GPIO pin number.
766 		 */
767 		spi->cs_gpio = cs->line;
768 	}
769 
770 	if (IS_ERR_OR_NULL(cs)) {
771 		dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
772 		return -ENODEV;
773 	}
774 
775 	if (!spi_get_ctldata(spi)) {
776 		if (gpio_is_valid(spi->cs_gpio)) {
777 			err = gpio_request_one(spi->cs_gpio, GPIOF_OUT_INIT_HIGH,
778 					       dev_name(&spi->dev));
779 			if (err) {
780 				dev_err(&spi->dev,
781 					"Failed to get /CS gpio [%d]: %d\n",
782 					spi->cs_gpio, err);
783 				goto err_gpio_req;
784 			}
785 		}
786 
787 		spi_set_ctldata(spi, cs);
788 	}
789 
790 	pm_runtime_get_sync(&sdd->pdev->dev);
791 
792 	/* Check if we can provide the requested rate */
793 	if (!sdd->port_conf->clk_from_cmu) {
794 		u32 psr, speed;
795 
796 		/* Max possible */
797 		speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1);
798 
799 		if (spi->max_speed_hz > speed)
800 			spi->max_speed_hz = speed;
801 
802 		psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1;
803 		psr &= S3C64XX_SPI_PSR_MASK;
804 		if (psr == S3C64XX_SPI_PSR_MASK)
805 			psr--;
806 
807 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
808 		if (spi->max_speed_hz < speed) {
809 			if (psr+1 < S3C64XX_SPI_PSR_MASK) {
810 				psr++;
811 			} else {
812 				err = -EINVAL;
813 				goto setup_exit;
814 			}
815 		}
816 
817 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
818 		if (spi->max_speed_hz >= speed) {
819 			spi->max_speed_hz = speed;
820 		} else {
821 			dev_err(&spi->dev, "Can't set %dHz transfer speed\n",
822 				spi->max_speed_hz);
823 			err = -EINVAL;
824 			goto setup_exit;
825 		}
826 	}
827 
828 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
829 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
830 	s3c64xx_spi_set_cs(spi, false);
831 
832 	return 0;
833 
834 setup_exit:
835 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
836 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
837 	/* setup() returns with device de-selected */
838 	s3c64xx_spi_set_cs(spi, false);
839 
840 	if (gpio_is_valid(spi->cs_gpio))
841 		gpio_free(spi->cs_gpio);
842 	spi_set_ctldata(spi, NULL);
843 
844 err_gpio_req:
845 	if (spi->dev.of_node)
846 		kfree(cs);
847 
848 	return err;
849 }
850 
851 static void s3c64xx_spi_cleanup(struct spi_device *spi)
852 {
853 	struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
854 
855 	if (gpio_is_valid(spi->cs_gpio)) {
856 		gpio_free(spi->cs_gpio);
857 		if (spi->dev.of_node)
858 			kfree(cs);
859 		else {
860 			/* On non-DT platforms, the SPI core sets
861 			 * spi->cs_gpio to -ENOENT and .setup()
862 			 * overrides it with the GPIO pin value
863 			 * passed using platform data.
864 			 */
865 			spi->cs_gpio = -ENOENT;
866 		}
867 	}
868 
869 	spi_set_ctldata(spi, NULL);
870 }
871 
872 static irqreturn_t s3c64xx_spi_irq(int irq, void *data)
873 {
874 	struct s3c64xx_spi_driver_data *sdd = data;
875 	struct spi_master *spi = sdd->master;
876 	unsigned int val, clr = 0;
877 
878 	val = readl(sdd->regs + S3C64XX_SPI_STATUS);
879 
880 	if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) {
881 		clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR;
882 		dev_err(&spi->dev, "RX overrun\n");
883 	}
884 	if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) {
885 		clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR;
886 		dev_err(&spi->dev, "RX underrun\n");
887 	}
888 	if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) {
889 		clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR;
890 		dev_err(&spi->dev, "TX overrun\n");
891 	}
892 	if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) {
893 		clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
894 		dev_err(&spi->dev, "TX underrun\n");
895 	}
896 
897 	/* Clear the pending irq by setting and then clearing it */
898 	writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR);
899 	writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR);
900 
901 	return IRQ_HANDLED;
902 }
903 
904 static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel)
905 {
906 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
907 	void __iomem *regs = sdd->regs;
908 	unsigned int val;
909 
910 	sdd->cur_speed = 0;
911 
912 	if (sci->no_cs)
913 		writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
914 	else if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
915 		writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
916 
917 	/* Disable Interrupts - we use Polling if not DMA mode */
918 	writel(0, regs + S3C64XX_SPI_INT_EN);
919 
920 	if (!sdd->port_conf->clk_from_cmu)
921 		writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
922 				regs + S3C64XX_SPI_CLK_CFG);
923 	writel(0, regs + S3C64XX_SPI_MODE_CFG);
924 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
925 
926 	/* Clear any irq pending bits, should set and clear the bits */
927 	val = S3C64XX_SPI_PND_RX_OVERRUN_CLR |
928 		S3C64XX_SPI_PND_RX_UNDERRUN_CLR |
929 		S3C64XX_SPI_PND_TX_OVERRUN_CLR |
930 		S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
931 	writel(val, regs + S3C64XX_SPI_PENDING_CLR);
932 	writel(0, regs + S3C64XX_SPI_PENDING_CLR);
933 
934 	writel(0, regs + S3C64XX_SPI_SWAP_CFG);
935 
936 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
937 	val &= ~S3C64XX_SPI_MODE_4BURST;
938 	val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
939 	val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
940 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
941 
942 	flush_fifo(sdd);
943 }
944 
945 #ifdef CONFIG_OF
946 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
947 {
948 	struct s3c64xx_spi_info *sci;
949 	u32 temp;
950 
951 	sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
952 	if (!sci)
953 		return ERR_PTR(-ENOMEM);
954 
955 	if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
956 		dev_warn(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
957 		sci->src_clk_nr = 0;
958 	} else {
959 		sci->src_clk_nr = temp;
960 	}
961 
962 	if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
963 		dev_warn(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
964 		sci->num_cs = 1;
965 	} else {
966 		sci->num_cs = temp;
967 	}
968 
969 	sci->no_cs = of_property_read_bool(dev->of_node, "no-cs-readback");
970 
971 	return sci;
972 }
973 #else
974 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
975 {
976 	return dev_get_platdata(dev);
977 }
978 #endif
979 
980 static const struct of_device_id s3c64xx_spi_dt_match[];
981 
982 static inline struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
983 						struct platform_device *pdev)
984 {
985 #ifdef CONFIG_OF
986 	if (pdev->dev.of_node) {
987 		const struct of_device_id *match;
988 		match = of_match_node(s3c64xx_spi_dt_match, pdev->dev.of_node);
989 		return (struct s3c64xx_spi_port_config *)match->data;
990 	}
991 #endif
992 	return (struct s3c64xx_spi_port_config *)
993 			 platform_get_device_id(pdev)->driver_data;
994 }
995 
996 static int s3c64xx_spi_probe(struct platform_device *pdev)
997 {
998 	struct resource	*mem_res;
999 	struct s3c64xx_spi_driver_data *sdd;
1000 	struct s3c64xx_spi_info *sci = dev_get_platdata(&pdev->dev);
1001 	struct spi_master *master;
1002 	int ret, irq;
1003 	char clk_name[16];
1004 
1005 	if (!sci && pdev->dev.of_node) {
1006 		sci = s3c64xx_spi_parse_dt(&pdev->dev);
1007 		if (IS_ERR(sci))
1008 			return PTR_ERR(sci);
1009 	}
1010 
1011 	if (!sci) {
1012 		dev_err(&pdev->dev, "platform_data missing!\n");
1013 		return -ENODEV;
1014 	}
1015 
1016 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1017 	if (mem_res == NULL) {
1018 		dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
1019 		return -ENXIO;
1020 	}
1021 
1022 	irq = platform_get_irq(pdev, 0);
1023 	if (irq < 0) {
1024 		dev_warn(&pdev->dev, "Failed to get IRQ: %d\n", irq);
1025 		return irq;
1026 	}
1027 
1028 	master = spi_alloc_master(&pdev->dev,
1029 				sizeof(struct s3c64xx_spi_driver_data));
1030 	if (master == NULL) {
1031 		dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
1032 		return -ENOMEM;
1033 	}
1034 
1035 	platform_set_drvdata(pdev, master);
1036 
1037 	sdd = spi_master_get_devdata(master);
1038 	sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
1039 	sdd->master = master;
1040 	sdd->cntrlr_info = sci;
1041 	sdd->pdev = pdev;
1042 	sdd->sfr_start = mem_res->start;
1043 	if (pdev->dev.of_node) {
1044 		ret = of_alias_get_id(pdev->dev.of_node, "spi");
1045 		if (ret < 0) {
1046 			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
1047 				ret);
1048 			goto err_deref_master;
1049 		}
1050 		sdd->port_id = ret;
1051 	} else {
1052 		sdd->port_id = pdev->id;
1053 	}
1054 
1055 	sdd->cur_bpw = 8;
1056 
1057 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
1058 	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
1059 
1060 	master->dev.of_node = pdev->dev.of_node;
1061 	master->bus_num = sdd->port_id;
1062 	master->setup = s3c64xx_spi_setup;
1063 	master->cleanup = s3c64xx_spi_cleanup;
1064 	master->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
1065 	master->prepare_message = s3c64xx_spi_prepare_message;
1066 	master->transfer_one = s3c64xx_spi_transfer_one;
1067 	master->num_chipselect = sci->num_cs;
1068 	master->dma_alignment = 8;
1069 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
1070 					SPI_BPW_MASK(8);
1071 	/* the spi->mode bits understood by this driver: */
1072 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1073 	master->auto_runtime_pm = true;
1074 	if (!is_polling(sdd))
1075 		master->can_dma = s3c64xx_spi_can_dma;
1076 
1077 	sdd->regs = devm_ioremap_resource(&pdev->dev, mem_res);
1078 	if (IS_ERR(sdd->regs)) {
1079 		ret = PTR_ERR(sdd->regs);
1080 		goto err_deref_master;
1081 	}
1082 
1083 	if (sci->cfg_gpio && sci->cfg_gpio()) {
1084 		dev_err(&pdev->dev, "Unable to config gpio\n");
1085 		ret = -EBUSY;
1086 		goto err_deref_master;
1087 	}
1088 
1089 	/* Setup clocks */
1090 	sdd->clk = devm_clk_get(&pdev->dev, "spi");
1091 	if (IS_ERR(sdd->clk)) {
1092 		dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
1093 		ret = PTR_ERR(sdd->clk);
1094 		goto err_deref_master;
1095 	}
1096 
1097 	ret = clk_prepare_enable(sdd->clk);
1098 	if (ret) {
1099 		dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
1100 		goto err_deref_master;
1101 	}
1102 
1103 	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
1104 	sdd->src_clk = devm_clk_get(&pdev->dev, clk_name);
1105 	if (IS_ERR(sdd->src_clk)) {
1106 		dev_err(&pdev->dev,
1107 			"Unable to acquire clock '%s'\n", clk_name);
1108 		ret = PTR_ERR(sdd->src_clk);
1109 		goto err_disable_clk;
1110 	}
1111 
1112 	ret = clk_prepare_enable(sdd->src_clk);
1113 	if (ret) {
1114 		dev_err(&pdev->dev, "Couldn't enable clock '%s'\n", clk_name);
1115 		goto err_disable_clk;
1116 	}
1117 
1118 	if (sdd->port_conf->clk_ioclk) {
1119 		sdd->ioclk = devm_clk_get(&pdev->dev, "spi_ioclk");
1120 		if (IS_ERR(sdd->ioclk)) {
1121 			dev_err(&pdev->dev, "Unable to acquire 'ioclk'\n");
1122 			ret = PTR_ERR(sdd->ioclk);
1123 			goto err_disable_src_clk;
1124 		}
1125 
1126 		ret = clk_prepare_enable(sdd->ioclk);
1127 		if (ret) {
1128 			dev_err(&pdev->dev, "Couldn't enable clock 'ioclk'\n");
1129 			goto err_disable_src_clk;
1130 		}
1131 	}
1132 
1133 	if (!is_polling(sdd)) {
1134 		/* Acquire DMA channels */
1135 		sdd->rx_dma.ch = dma_request_slave_channel_reason(&pdev->dev,
1136 								  "rx");
1137 		if (IS_ERR(sdd->rx_dma.ch)) {
1138 			dev_err(&pdev->dev, "Failed to get RX DMA channel\n");
1139 			ret = PTR_ERR(sdd->rx_dma.ch);
1140 			goto err_disable_io_clk;
1141 		}
1142 		sdd->tx_dma.ch = dma_request_slave_channel_reason(&pdev->dev,
1143 								  "tx");
1144 		if (IS_ERR(sdd->tx_dma.ch)) {
1145 			dev_err(&pdev->dev, "Failed to get TX DMA channel\n");
1146 			ret = PTR_ERR(sdd->tx_dma.ch);
1147 			goto err_release_rx_dma;
1148 		}
1149 	}
1150 
1151 	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1152 	pm_runtime_use_autosuspend(&pdev->dev);
1153 	pm_runtime_set_active(&pdev->dev);
1154 	pm_runtime_enable(&pdev->dev);
1155 	pm_runtime_get_sync(&pdev->dev);
1156 
1157 	/* Setup Deufult Mode */
1158 	s3c64xx_spi_hwinit(sdd, sdd->port_id);
1159 
1160 	spin_lock_init(&sdd->lock);
1161 	init_completion(&sdd->xfer_completion);
1162 
1163 	ret = devm_request_irq(&pdev->dev, irq, s3c64xx_spi_irq, 0,
1164 				"spi-s3c64xx", sdd);
1165 	if (ret != 0) {
1166 		dev_err(&pdev->dev, "Failed to request IRQ %d: %d\n",
1167 			irq, ret);
1168 		goto err_pm_put;
1169 	}
1170 
1171 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1172 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1173 	       sdd->regs + S3C64XX_SPI_INT_EN);
1174 
1175 	ret = devm_spi_register_master(&pdev->dev, master);
1176 	if (ret != 0) {
1177 		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
1178 		goto err_pm_put;
1179 	}
1180 
1181 	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",
1182 					sdd->port_id, master->num_chipselect);
1183 	dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\n",
1184 					mem_res, (FIFO_LVL_MASK(sdd) >> 1) + 1);
1185 
1186 	pm_runtime_mark_last_busy(&pdev->dev);
1187 	pm_runtime_put_autosuspend(&pdev->dev);
1188 
1189 	return 0;
1190 
1191 err_pm_put:
1192 	pm_runtime_put_noidle(&pdev->dev);
1193 	pm_runtime_disable(&pdev->dev);
1194 	pm_runtime_set_suspended(&pdev->dev);
1195 
1196 	if (!is_polling(sdd))
1197 		dma_release_channel(sdd->tx_dma.ch);
1198 err_release_rx_dma:
1199 	if (!is_polling(sdd))
1200 		dma_release_channel(sdd->rx_dma.ch);
1201 err_disable_io_clk:
1202 	clk_disable_unprepare(sdd->ioclk);
1203 err_disable_src_clk:
1204 	clk_disable_unprepare(sdd->src_clk);
1205 err_disable_clk:
1206 	clk_disable_unprepare(sdd->clk);
1207 err_deref_master:
1208 	spi_master_put(master);
1209 
1210 	return ret;
1211 }
1212 
1213 static int s3c64xx_spi_remove(struct platform_device *pdev)
1214 {
1215 	struct spi_master *master = platform_get_drvdata(pdev);
1216 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1217 
1218 	pm_runtime_get_sync(&pdev->dev);
1219 
1220 	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
1221 
1222 	if (!is_polling(sdd)) {
1223 		dma_release_channel(sdd->rx_dma.ch);
1224 		dma_release_channel(sdd->tx_dma.ch);
1225 	}
1226 
1227 	clk_disable_unprepare(sdd->ioclk);
1228 
1229 	clk_disable_unprepare(sdd->src_clk);
1230 
1231 	clk_disable_unprepare(sdd->clk);
1232 
1233 	pm_runtime_put_noidle(&pdev->dev);
1234 	pm_runtime_disable(&pdev->dev);
1235 	pm_runtime_set_suspended(&pdev->dev);
1236 
1237 	return 0;
1238 }
1239 
1240 #ifdef CONFIG_PM_SLEEP
1241 static int s3c64xx_spi_suspend(struct device *dev)
1242 {
1243 	struct spi_master *master = dev_get_drvdata(dev);
1244 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1245 
1246 	int ret = spi_master_suspend(master);
1247 	if (ret)
1248 		return ret;
1249 
1250 	ret = pm_runtime_force_suspend(dev);
1251 	if (ret < 0)
1252 		return ret;
1253 
1254 	sdd->cur_speed = 0; /* Output Clock is stopped */
1255 
1256 	return 0;
1257 }
1258 
1259 static int s3c64xx_spi_resume(struct device *dev)
1260 {
1261 	struct spi_master *master = dev_get_drvdata(dev);
1262 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1263 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1264 	int ret;
1265 
1266 	if (sci->cfg_gpio)
1267 		sci->cfg_gpio();
1268 
1269 	ret = pm_runtime_force_resume(dev);
1270 	if (ret < 0)
1271 		return ret;
1272 
1273 	s3c64xx_spi_hwinit(sdd, sdd->port_id);
1274 
1275 	return spi_master_resume(master);
1276 }
1277 #endif /* CONFIG_PM_SLEEP */
1278 
1279 #ifdef CONFIG_PM
1280 static int s3c64xx_spi_runtime_suspend(struct device *dev)
1281 {
1282 	struct spi_master *master = dev_get_drvdata(dev);
1283 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1284 
1285 	clk_disable_unprepare(sdd->clk);
1286 	clk_disable_unprepare(sdd->src_clk);
1287 	clk_disable_unprepare(sdd->ioclk);
1288 
1289 	return 0;
1290 }
1291 
1292 static int s3c64xx_spi_runtime_resume(struct device *dev)
1293 {
1294 	struct spi_master *master = dev_get_drvdata(dev);
1295 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1296 	int ret;
1297 
1298 	if (sdd->port_conf->clk_ioclk) {
1299 		ret = clk_prepare_enable(sdd->ioclk);
1300 		if (ret != 0)
1301 			return ret;
1302 	}
1303 
1304 	ret = clk_prepare_enable(sdd->src_clk);
1305 	if (ret != 0)
1306 		goto err_disable_ioclk;
1307 
1308 	ret = clk_prepare_enable(sdd->clk);
1309 	if (ret != 0)
1310 		goto err_disable_src_clk;
1311 
1312 	return 0;
1313 
1314 err_disable_src_clk:
1315 	clk_disable_unprepare(sdd->src_clk);
1316 err_disable_ioclk:
1317 	clk_disable_unprepare(sdd->ioclk);
1318 
1319 	return ret;
1320 }
1321 #endif /* CONFIG_PM */
1322 
1323 static const struct dev_pm_ops s3c64xx_spi_pm = {
1324 	SET_SYSTEM_SLEEP_PM_OPS(s3c64xx_spi_suspend, s3c64xx_spi_resume)
1325 	SET_RUNTIME_PM_OPS(s3c64xx_spi_runtime_suspend,
1326 			   s3c64xx_spi_runtime_resume, NULL)
1327 };
1328 
1329 static struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
1330 	.fifo_lvl_mask	= { 0x7f },
1331 	.rx_lvl_offset	= 13,
1332 	.tx_st_done	= 21,
1333 	.high_speed	= true,
1334 };
1335 
1336 static struct s3c64xx_spi_port_config s3c6410_spi_port_config = {
1337 	.fifo_lvl_mask	= { 0x7f, 0x7F },
1338 	.rx_lvl_offset	= 13,
1339 	.tx_st_done	= 21,
1340 };
1341 
1342 static struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
1343 	.fifo_lvl_mask	= { 0x1ff, 0x7F },
1344 	.rx_lvl_offset	= 15,
1345 	.tx_st_done	= 25,
1346 	.high_speed	= true,
1347 };
1348 
1349 static struct s3c64xx_spi_port_config exynos4_spi_port_config = {
1350 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F },
1351 	.rx_lvl_offset	= 15,
1352 	.tx_st_done	= 25,
1353 	.high_speed	= true,
1354 	.clk_from_cmu	= true,
1355 };
1356 
1357 static struct s3c64xx_spi_port_config exynos5440_spi_port_config = {
1358 	.fifo_lvl_mask	= { 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_POLL,
1364 };
1365 
1366 static struct s3c64xx_spi_port_config exynos7_spi_port_config = {
1367 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},
1368 	.rx_lvl_offset	= 15,
1369 	.tx_st_done	= 25,
1370 	.high_speed	= true,
1371 	.clk_from_cmu	= true,
1372 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1373 };
1374 
1375 static struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
1376 	.fifo_lvl_mask	= { 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff},
1377 	.rx_lvl_offset	= 15,
1378 	.tx_st_done	= 25,
1379 	.high_speed	= true,
1380 	.clk_from_cmu	= true,
1381 	.clk_ioclk	= true,
1382 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1383 };
1384 
1385 static const struct platform_device_id s3c64xx_spi_driver_ids[] = {
1386 	{
1387 		.name		= "s3c2443-spi",
1388 		.driver_data	= (kernel_ulong_t)&s3c2443_spi_port_config,
1389 	}, {
1390 		.name		= "s3c6410-spi",
1391 		.driver_data	= (kernel_ulong_t)&s3c6410_spi_port_config,
1392 	},
1393 	{ },
1394 };
1395 
1396 static const struct of_device_id s3c64xx_spi_dt_match[] = {
1397 	{ .compatible = "samsung,s3c2443-spi",
1398 			.data = (void *)&s3c2443_spi_port_config,
1399 	},
1400 	{ .compatible = "samsung,s3c6410-spi",
1401 			.data = (void *)&s3c6410_spi_port_config,
1402 	},
1403 	{ .compatible = "samsung,s5pv210-spi",
1404 			.data = (void *)&s5pv210_spi_port_config,
1405 	},
1406 	{ .compatible = "samsung,exynos4210-spi",
1407 			.data = (void *)&exynos4_spi_port_config,
1408 	},
1409 	{ .compatible = "samsung,exynos5440-spi",
1410 			.data = (void *)&exynos5440_spi_port_config,
1411 	},
1412 	{ .compatible = "samsung,exynos7-spi",
1413 			.data = (void *)&exynos7_spi_port_config,
1414 	},
1415 	{ .compatible = "samsung,exynos5433-spi",
1416 			.data = (void *)&exynos5433_spi_port_config,
1417 	},
1418 	{ },
1419 };
1420 MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
1421 
1422 static struct platform_driver s3c64xx_spi_driver = {
1423 	.driver = {
1424 		.name	= "s3c64xx-spi",
1425 		.pm = &s3c64xx_spi_pm,
1426 		.of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
1427 	},
1428 	.probe = s3c64xx_spi_probe,
1429 	.remove = s3c64xx_spi_remove,
1430 	.id_table = s3c64xx_spi_driver_ids,
1431 };
1432 MODULE_ALIAS("platform:s3c64xx-spi");
1433 
1434 module_platform_driver(s3c64xx_spi_driver);
1435 
1436 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1437 MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1438 MODULE_LICENSE("GPL");
1439