xref: /openbmc/linux/drivers/spi/spi-s3c64xx.c (revision 9a6b55ac)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Copyright (c) 2009 Samsung Electronics Co., Ltd.
4 //      Jaswinder Singh <jassi.brar@samsung.com>
5 
6 #include <linux/init.h>
7 #include <linux/module.h>
8 #include <linux/interrupt.h>
9 #include <linux/delay.h>
10 #include <linux/clk.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/dmaengine.h>
13 #include <linux/platform_device.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/spi/spi.h>
16 #include <linux/gpio.h>
17 #include <linux/of.h>
18 #include <linux/of_gpio.h>
19 
20 #include <linux/platform_data/spi-s3c64xx.h>
21 
22 #define MAX_SPI_PORTS		6
23 #define S3C64XX_SPI_QUIRK_POLL		(1 << 0)
24 #define S3C64XX_SPI_QUIRK_CS_AUTO	(1 << 1)
25 #define AUTOSUSPEND_TIMEOUT	2000
26 
27 /* Registers and bit-fields */
28 
29 #define S3C64XX_SPI_CH_CFG		0x00
30 #define S3C64XX_SPI_CLK_CFG		0x04
31 #define S3C64XX_SPI_MODE_CFG		0x08
32 #define S3C64XX_SPI_SLAVE_SEL		0x0C
33 #define S3C64XX_SPI_INT_EN		0x10
34 #define S3C64XX_SPI_STATUS		0x14
35 #define S3C64XX_SPI_TX_DATA		0x18
36 #define S3C64XX_SPI_RX_DATA		0x1C
37 #define S3C64XX_SPI_PACKET_CNT		0x20
38 #define S3C64XX_SPI_PENDING_CLR		0x24
39 #define S3C64XX_SPI_SWAP_CFG		0x28
40 #define S3C64XX_SPI_FB_CLK		0x2C
41 
42 #define S3C64XX_SPI_CH_HS_EN		(1<<6)	/* High Speed Enable */
43 #define S3C64XX_SPI_CH_SW_RST		(1<<5)
44 #define S3C64XX_SPI_CH_SLAVE		(1<<4)
45 #define S3C64XX_SPI_CPOL_L		(1<<3)
46 #define S3C64XX_SPI_CPHA_B		(1<<2)
47 #define S3C64XX_SPI_CH_RXCH_ON		(1<<1)
48 #define S3C64XX_SPI_CH_TXCH_ON		(1<<0)
49 
50 #define S3C64XX_SPI_CLKSEL_SRCMSK	(3<<9)
51 #define S3C64XX_SPI_CLKSEL_SRCSHFT	9
52 #define S3C64XX_SPI_ENCLK_ENABLE	(1<<8)
53 #define S3C64XX_SPI_PSR_MASK		0xff
54 
55 #define S3C64XX_SPI_MODE_CH_TSZ_BYTE		(0<<29)
56 #define S3C64XX_SPI_MODE_CH_TSZ_HALFWORD	(1<<29)
57 #define S3C64XX_SPI_MODE_CH_TSZ_WORD		(2<<29)
58 #define S3C64XX_SPI_MODE_CH_TSZ_MASK		(3<<29)
59 #define S3C64XX_SPI_MODE_BUS_TSZ_BYTE		(0<<17)
60 #define S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD	(1<<17)
61 #define S3C64XX_SPI_MODE_BUS_TSZ_WORD		(2<<17)
62 #define S3C64XX_SPI_MODE_BUS_TSZ_MASK		(3<<17)
63 #define S3C64XX_SPI_MODE_RXDMA_ON		(1<<2)
64 #define S3C64XX_SPI_MODE_TXDMA_ON		(1<<1)
65 #define S3C64XX_SPI_MODE_4BURST			(1<<0)
66 
67 #define S3C64XX_SPI_SLAVE_AUTO			(1<<1)
68 #define S3C64XX_SPI_SLAVE_SIG_INACT		(1<<0)
69 #define S3C64XX_SPI_SLAVE_NSC_CNT_2		(2<<4)
70 
71 #define S3C64XX_SPI_INT_TRAILING_EN		(1<<6)
72 #define S3C64XX_SPI_INT_RX_OVERRUN_EN		(1<<5)
73 #define S3C64XX_SPI_INT_RX_UNDERRUN_EN		(1<<4)
74 #define S3C64XX_SPI_INT_TX_OVERRUN_EN		(1<<3)
75 #define S3C64XX_SPI_INT_TX_UNDERRUN_EN		(1<<2)
76 #define S3C64XX_SPI_INT_RX_FIFORDY_EN		(1<<1)
77 #define S3C64XX_SPI_INT_TX_FIFORDY_EN		(1<<0)
78 
79 #define S3C64XX_SPI_ST_RX_OVERRUN_ERR		(1<<5)
80 #define S3C64XX_SPI_ST_RX_UNDERRUN_ERR		(1<<4)
81 #define S3C64XX_SPI_ST_TX_OVERRUN_ERR		(1<<3)
82 #define S3C64XX_SPI_ST_TX_UNDERRUN_ERR		(1<<2)
83 #define S3C64XX_SPI_ST_RX_FIFORDY		(1<<1)
84 #define S3C64XX_SPI_ST_TX_FIFORDY		(1<<0)
85 
86 #define S3C64XX_SPI_PACKET_CNT_EN		(1<<16)
87 
88 #define S3C64XX_SPI_PND_TX_UNDERRUN_CLR		(1<<4)
89 #define S3C64XX_SPI_PND_TX_OVERRUN_CLR		(1<<3)
90 #define S3C64XX_SPI_PND_RX_UNDERRUN_CLR		(1<<2)
91 #define S3C64XX_SPI_PND_RX_OVERRUN_CLR		(1<<1)
92 #define S3C64XX_SPI_PND_TRAILING_CLR		(1<<0)
93 
94 #define S3C64XX_SPI_SWAP_RX_HALF_WORD		(1<<7)
95 #define S3C64XX_SPI_SWAP_RX_BYTE		(1<<6)
96 #define S3C64XX_SPI_SWAP_RX_BIT			(1<<5)
97 #define S3C64XX_SPI_SWAP_RX_EN			(1<<4)
98 #define S3C64XX_SPI_SWAP_TX_HALF_WORD		(1<<3)
99 #define S3C64XX_SPI_SWAP_TX_BYTE		(1<<2)
100 #define S3C64XX_SPI_SWAP_TX_BIT			(1<<1)
101 #define S3C64XX_SPI_SWAP_TX_EN			(1<<0)
102 
103 #define S3C64XX_SPI_FBCLK_MSK			(3<<0)
104 
105 #define FIFO_LVL_MASK(i) ((i)->port_conf->fifo_lvl_mask[i->port_id])
106 #define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & \
107 				(1 << (i)->port_conf->tx_st_done)) ? 1 : 0)
108 #define TX_FIFO_LVL(v, i) (((v) >> 6) & FIFO_LVL_MASK(i))
109 #define RX_FIFO_LVL(v, i) (((v) >> (i)->port_conf->rx_lvl_offset) & \
110 					FIFO_LVL_MASK(i))
111 
112 #define S3C64XX_SPI_MAX_TRAILCNT	0x3ff
113 #define S3C64XX_SPI_TRAILCNT_OFF	19
114 
115 #define S3C64XX_SPI_TRAILCNT		S3C64XX_SPI_MAX_TRAILCNT
116 
117 #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
118 #define is_polling(x)	(x->port_conf->quirks & S3C64XX_SPI_QUIRK_POLL)
119 
120 #define RXBUSY    (1<<2)
121 #define TXBUSY    (1<<3)
122 
123 struct s3c64xx_spi_dma_data {
124 	struct dma_chan *ch;
125 	enum dma_transfer_direction direction;
126 };
127 
128 /**
129  * struct s3c64xx_spi_info - SPI Controller hardware info
130  * @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
131  * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
132  * @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
133  * @high_speed: True, if the controller supports HIGH_SPEED_EN bit.
134  * @clk_from_cmu: True, if the controller does not include a clock mux and
135  *	prescaler unit.
136  *
137  * The Samsung s3c64xx SPI controller are used on various Samsung SoC's but
138  * differ in some aspects such as the size of the fifo and spi bus clock
139  * setup. Such differences are specified to the driver using this structure
140  * which is provided as driver data to the driver.
141  */
142 struct s3c64xx_spi_port_config {
143 	int	fifo_lvl_mask[MAX_SPI_PORTS];
144 	int	rx_lvl_offset;
145 	int	tx_st_done;
146 	int	quirks;
147 	bool	high_speed;
148 	bool	clk_from_cmu;
149 	bool	clk_ioclk;
150 };
151 
152 /**
153  * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
154  * @clk: Pointer to the spi clock.
155  * @src_clk: Pointer to the clock used to generate SPI signals.
156  * @ioclk: Pointer to the i/o clock between master and slave
157  * @master: Pointer to the SPI Protocol master.
158  * @cntrlr_info: Platform specific data for the controller this driver manages.
159  * @lock: Controller specific lock.
160  * @state: Set of FLAGS to indicate status.
161  * @rx_dmach: Controller's DMA channel for Rx.
162  * @tx_dmach: Controller's DMA channel for Tx.
163  * @sfr_start: BUS address of SPI controller regs.
164  * @regs: Pointer to ioremap'ed controller registers.
165  * @irq: interrupt
166  * @xfer_completion: To indicate completion of xfer task.
167  * @cur_mode: Stores the active configuration of the controller.
168  * @cur_bpw: Stores the active bits per word settings.
169  * @cur_speed: Stores the active xfer clock speed.
170  */
171 struct s3c64xx_spi_driver_data {
172 	void __iomem                    *regs;
173 	struct clk                      *clk;
174 	struct clk                      *src_clk;
175 	struct clk                      *ioclk;
176 	struct platform_device          *pdev;
177 	struct spi_master               *master;
178 	struct s3c64xx_spi_info  *cntrlr_info;
179 	spinlock_t                      lock;
180 	unsigned long                   sfr_start;
181 	struct completion               xfer_completion;
182 	unsigned                        state;
183 	unsigned                        cur_mode, cur_bpw;
184 	unsigned                        cur_speed;
185 	struct s3c64xx_spi_dma_data	rx_dma;
186 	struct s3c64xx_spi_dma_data	tx_dma;
187 	struct s3c64xx_spi_port_config	*port_conf;
188 	unsigned int			port_id;
189 };
190 
191 static void s3c64xx_flush_fifo(struct s3c64xx_spi_driver_data *sdd)
192 {
193 	void __iomem *regs = sdd->regs;
194 	unsigned long loops;
195 	u32 val;
196 
197 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
198 
199 	val = readl(regs + S3C64XX_SPI_CH_CFG);
200 	val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON);
201 	writel(val, regs + S3C64XX_SPI_CH_CFG);
202 
203 	val = readl(regs + S3C64XX_SPI_CH_CFG);
204 	val |= S3C64XX_SPI_CH_SW_RST;
205 	val &= ~S3C64XX_SPI_CH_HS_EN;
206 	writel(val, regs + S3C64XX_SPI_CH_CFG);
207 
208 	/* Flush TxFIFO*/
209 	loops = msecs_to_loops(1);
210 	do {
211 		val = readl(regs + S3C64XX_SPI_STATUS);
212 	} while (TX_FIFO_LVL(val, sdd) && loops--);
213 
214 	if (loops == 0)
215 		dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n");
216 
217 	/* Flush RxFIFO*/
218 	loops = msecs_to_loops(1);
219 	do {
220 		val = readl(regs + S3C64XX_SPI_STATUS);
221 		if (RX_FIFO_LVL(val, sdd))
222 			readl(regs + S3C64XX_SPI_RX_DATA);
223 		else
224 			break;
225 	} while (loops--);
226 
227 	if (loops == 0)
228 		dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n");
229 
230 	val = readl(regs + S3C64XX_SPI_CH_CFG);
231 	val &= ~S3C64XX_SPI_CH_SW_RST;
232 	writel(val, regs + S3C64XX_SPI_CH_CFG);
233 
234 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
235 	val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
236 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
237 }
238 
239 static void s3c64xx_spi_dmacb(void *data)
240 {
241 	struct s3c64xx_spi_driver_data *sdd;
242 	struct s3c64xx_spi_dma_data *dma = data;
243 	unsigned long flags;
244 
245 	if (dma->direction == DMA_DEV_TO_MEM)
246 		sdd = container_of(data,
247 			struct s3c64xx_spi_driver_data, rx_dma);
248 	else
249 		sdd = container_of(data,
250 			struct s3c64xx_spi_driver_data, tx_dma);
251 
252 	spin_lock_irqsave(&sdd->lock, flags);
253 
254 	if (dma->direction == DMA_DEV_TO_MEM) {
255 		sdd->state &= ~RXBUSY;
256 		if (!(sdd->state & TXBUSY))
257 			complete(&sdd->xfer_completion);
258 	} else {
259 		sdd->state &= ~TXBUSY;
260 		if (!(sdd->state & RXBUSY))
261 			complete(&sdd->xfer_completion);
262 	}
263 
264 	spin_unlock_irqrestore(&sdd->lock, flags);
265 }
266 
267 static void prepare_dma(struct s3c64xx_spi_dma_data *dma,
268 			struct sg_table *sgt)
269 {
270 	struct s3c64xx_spi_driver_data *sdd;
271 	struct dma_slave_config config;
272 	struct dma_async_tx_descriptor *desc;
273 
274 	memset(&config, 0, sizeof(config));
275 
276 	if (dma->direction == DMA_DEV_TO_MEM) {
277 		sdd = container_of((void *)dma,
278 			struct s3c64xx_spi_driver_data, rx_dma);
279 		config.direction = dma->direction;
280 		config.src_addr = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
281 		config.src_addr_width = sdd->cur_bpw / 8;
282 		config.src_maxburst = 1;
283 		dmaengine_slave_config(dma->ch, &config);
284 	} else {
285 		sdd = container_of((void *)dma,
286 			struct s3c64xx_spi_driver_data, tx_dma);
287 		config.direction = dma->direction;
288 		config.dst_addr = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
289 		config.dst_addr_width = sdd->cur_bpw / 8;
290 		config.dst_maxburst = 1;
291 		dmaengine_slave_config(dma->ch, &config);
292 	}
293 
294 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
295 				       dma->direction, DMA_PREP_INTERRUPT);
296 
297 	desc->callback = s3c64xx_spi_dmacb;
298 	desc->callback_param = dma;
299 
300 	dmaengine_submit(desc);
301 	dma_async_issue_pending(dma->ch);
302 }
303 
304 static void s3c64xx_spi_set_cs(struct spi_device *spi, bool enable)
305 {
306 	struct s3c64xx_spi_driver_data *sdd =
307 					spi_master_get_devdata(spi->master);
308 
309 	if (sdd->cntrlr_info->no_cs)
310 		return;
311 
312 	if (enable) {
313 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO)) {
314 			writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
315 		} else {
316 			u32 ssel = readl(sdd->regs + S3C64XX_SPI_SLAVE_SEL);
317 
318 			ssel |= (S3C64XX_SPI_SLAVE_AUTO |
319 						S3C64XX_SPI_SLAVE_NSC_CNT_2);
320 			writel(ssel, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
321 		}
322 	} else {
323 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
324 			writel(S3C64XX_SPI_SLAVE_SIG_INACT,
325 			       sdd->regs + S3C64XX_SPI_SLAVE_SEL);
326 	}
327 }
328 
329 static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
330 {
331 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
332 
333 	if (is_polling(sdd))
334 		return 0;
335 
336 	spi->dma_rx = sdd->rx_dma.ch;
337 	spi->dma_tx = sdd->tx_dma.ch;
338 
339 	return 0;
340 }
341 
342 static bool s3c64xx_spi_can_dma(struct spi_master *master,
343 				struct spi_device *spi,
344 				struct spi_transfer *xfer)
345 {
346 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
347 
348 	return xfer->len > (FIFO_LVL_MASK(sdd) >> 1) + 1;
349 }
350 
351 static void s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
352 				    struct spi_transfer *xfer, int dma_mode)
353 {
354 	void __iomem *regs = sdd->regs;
355 	u32 modecfg, chcfg;
356 
357 	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
358 	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
359 
360 	chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
361 	chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
362 
363 	if (dma_mode) {
364 		chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
365 	} else {
366 		/* Always shift in data in FIFO, even if xfer is Tx only,
367 		 * this helps setting PCKT_CNT value for generating clocks
368 		 * as exactly needed.
369 		 */
370 		chcfg |= S3C64XX_SPI_CH_RXCH_ON;
371 		writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
372 					| S3C64XX_SPI_PACKET_CNT_EN,
373 					regs + S3C64XX_SPI_PACKET_CNT);
374 	}
375 
376 	if (xfer->tx_buf != NULL) {
377 		sdd->state |= TXBUSY;
378 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
379 		if (dma_mode) {
380 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
381 			prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
382 		} else {
383 			switch (sdd->cur_bpw) {
384 			case 32:
385 				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
386 					xfer->tx_buf, xfer->len / 4);
387 				break;
388 			case 16:
389 				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
390 					xfer->tx_buf, xfer->len / 2);
391 				break;
392 			default:
393 				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
394 					xfer->tx_buf, xfer->len);
395 				break;
396 			}
397 		}
398 	}
399 
400 	if (xfer->rx_buf != NULL) {
401 		sdd->state |= RXBUSY;
402 
403 		if (sdd->port_conf->high_speed && sdd->cur_speed >= 30000000UL
404 					&& !(sdd->cur_mode & SPI_CPHA))
405 			chcfg |= S3C64XX_SPI_CH_HS_EN;
406 
407 		if (dma_mode) {
408 			modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
409 			chcfg |= S3C64XX_SPI_CH_RXCH_ON;
410 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
411 					| S3C64XX_SPI_PACKET_CNT_EN,
412 					regs + S3C64XX_SPI_PACKET_CNT);
413 			prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
414 		}
415 	}
416 
417 	writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
418 	writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
419 }
420 
421 static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
422 					int timeout_ms)
423 {
424 	void __iomem *regs = sdd->regs;
425 	unsigned long val = 1;
426 	u32 status;
427 
428 	/* max fifo depth available */
429 	u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
430 
431 	if (timeout_ms)
432 		val = msecs_to_loops(timeout_ms);
433 
434 	do {
435 		status = readl(regs + S3C64XX_SPI_STATUS);
436 	} while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
437 
438 	/* return the actual received data length */
439 	return RX_FIFO_LVL(status, sdd);
440 }
441 
442 static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
443 				struct spi_transfer *xfer)
444 {
445 	void __iomem *regs = sdd->regs;
446 	unsigned long val;
447 	u32 status;
448 	int ms;
449 
450 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
451 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
452 	ms += 10; /* some tolerance */
453 
454 	val = msecs_to_jiffies(ms) + 10;
455 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
456 
457 	/*
458 	 * If the previous xfer was completed within timeout, then
459 	 * proceed further else return -EIO.
460 	 * DmaTx returns after simply writing data in the FIFO,
461 	 * w/o waiting for real transmission on the bus to finish.
462 	 * DmaRx returns only after Dma read data from FIFO which
463 	 * needs bus transmission to finish, so we don't worry if
464 	 * Xfer involved Rx(with or without Tx).
465 	 */
466 	if (val && !xfer->rx_buf) {
467 		val = msecs_to_loops(10);
468 		status = readl(regs + S3C64XX_SPI_STATUS);
469 		while ((TX_FIFO_LVL(status, sdd)
470 			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
471 		       && --val) {
472 			cpu_relax();
473 			status = readl(regs + S3C64XX_SPI_STATUS);
474 		}
475 
476 	}
477 
478 	/* If timed out while checking rx/tx status return error */
479 	if (!val)
480 		return -EIO;
481 
482 	return 0;
483 }
484 
485 static int s3c64xx_wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
486 				struct spi_transfer *xfer)
487 {
488 	void __iomem *regs = sdd->regs;
489 	unsigned long val;
490 	u32 status;
491 	int loops;
492 	u32 cpy_len;
493 	u8 *buf;
494 	int ms;
495 
496 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
497 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
498 	ms += 10; /* some tolerance */
499 
500 	val = msecs_to_loops(ms);
501 	do {
502 		status = readl(regs + S3C64XX_SPI_STATUS);
503 	} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
504 
505 	if (!val)
506 		return -EIO;
507 
508 	/* If it was only Tx */
509 	if (!xfer->rx_buf) {
510 		sdd->state &= ~TXBUSY;
511 		return 0;
512 	}
513 
514 	/*
515 	 * If the receive length is bigger than the controller fifo
516 	 * size, calculate the loops and read the fifo as many times.
517 	 * loops = length / max fifo size (calculated by using the
518 	 * fifo mask).
519 	 * For any size less than the fifo size the below code is
520 	 * executed atleast once.
521 	 */
522 	loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
523 	buf = xfer->rx_buf;
524 	do {
525 		/* wait for data to be received in the fifo */
526 		cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
527 						       (loops ? ms : 0));
528 
529 		switch (sdd->cur_bpw) {
530 		case 32:
531 			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
532 				     buf, cpy_len / 4);
533 			break;
534 		case 16:
535 			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
536 				     buf, cpy_len / 2);
537 			break;
538 		default:
539 			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
540 				    buf, cpy_len);
541 			break;
542 		}
543 
544 		buf = buf + cpy_len;
545 	} while (loops--);
546 	sdd->state &= ~RXBUSY;
547 
548 	return 0;
549 }
550 
551 static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
552 {
553 	void __iomem *regs = sdd->regs;
554 	u32 val;
555 
556 	/* Disable Clock */
557 	if (!sdd->port_conf->clk_from_cmu) {
558 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
559 		val &= ~S3C64XX_SPI_ENCLK_ENABLE;
560 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
561 	}
562 
563 	/* Set Polarity and Phase */
564 	val = readl(regs + S3C64XX_SPI_CH_CFG);
565 	val &= ~(S3C64XX_SPI_CH_SLAVE |
566 			S3C64XX_SPI_CPOL_L |
567 			S3C64XX_SPI_CPHA_B);
568 
569 	if (sdd->cur_mode & SPI_CPOL)
570 		val |= S3C64XX_SPI_CPOL_L;
571 
572 	if (sdd->cur_mode & SPI_CPHA)
573 		val |= S3C64XX_SPI_CPHA_B;
574 
575 	writel(val, regs + S3C64XX_SPI_CH_CFG);
576 
577 	/* Set Channel & DMA Mode */
578 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
579 	val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
580 			| S3C64XX_SPI_MODE_CH_TSZ_MASK);
581 
582 	switch (sdd->cur_bpw) {
583 	case 32:
584 		val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
585 		val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;
586 		break;
587 	case 16:
588 		val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
589 		val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;
590 		break;
591 	default:
592 		val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
593 		val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;
594 		break;
595 	}
596 
597 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
598 
599 	if (sdd->port_conf->clk_from_cmu) {
600 		/* The src_clk clock is divided internally by 2 */
601 		clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
602 	} else {
603 		/* Configure Clock */
604 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
605 		val &= ~S3C64XX_SPI_PSR_MASK;
606 		val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1)
607 				& S3C64XX_SPI_PSR_MASK);
608 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
609 
610 		/* Enable Clock */
611 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
612 		val |= S3C64XX_SPI_ENCLK_ENABLE;
613 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
614 	}
615 }
616 
617 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
618 
619 static int s3c64xx_spi_prepare_message(struct spi_master *master,
620 				       struct spi_message *msg)
621 {
622 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
623 	struct spi_device *spi = msg->spi;
624 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
625 
626 	/* Configure feedback delay */
627 	writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
628 
629 	return 0;
630 }
631 
632 static int s3c64xx_spi_transfer_one(struct spi_master *master,
633 				    struct spi_device *spi,
634 				    struct spi_transfer *xfer)
635 {
636 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
637 	const unsigned int fifo_len = (FIFO_LVL_MASK(sdd) >> 1) + 1;
638 	const void *tx_buf = NULL;
639 	void *rx_buf = NULL;
640 	int target_len = 0, origin_len = 0;
641 	int use_dma = 0;
642 	int status;
643 	u32 speed;
644 	u8 bpw;
645 	unsigned long flags;
646 
647 	reinit_completion(&sdd->xfer_completion);
648 
649 	/* Only BPW and Speed may change across transfers */
650 	bpw = xfer->bits_per_word;
651 	speed = xfer->speed_hz;
652 
653 	if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
654 		sdd->cur_bpw = bpw;
655 		sdd->cur_speed = speed;
656 		sdd->cur_mode = spi->mode;
657 		s3c64xx_spi_config(sdd);
658 	}
659 
660 	if (!is_polling(sdd) && (xfer->len > fifo_len) &&
661 	    sdd->rx_dma.ch && sdd->tx_dma.ch) {
662 		use_dma = 1;
663 
664 	} else if (is_polling(sdd) && xfer->len > fifo_len) {
665 		tx_buf = xfer->tx_buf;
666 		rx_buf = xfer->rx_buf;
667 		origin_len = xfer->len;
668 
669 		target_len = xfer->len;
670 		if (xfer->len > fifo_len)
671 			xfer->len = fifo_len;
672 	}
673 
674 	do {
675 		spin_lock_irqsave(&sdd->lock, flags);
676 
677 		/* Pending only which is to be done */
678 		sdd->state &= ~RXBUSY;
679 		sdd->state &= ~TXBUSY;
680 
681 		s3c64xx_enable_datapath(sdd, xfer, use_dma);
682 
683 		/* Start the signals */
684 		s3c64xx_spi_set_cs(spi, true);
685 
686 		spin_unlock_irqrestore(&sdd->lock, flags);
687 
688 		if (use_dma)
689 			status = s3c64xx_wait_for_dma(sdd, xfer);
690 		else
691 			status = s3c64xx_wait_for_pio(sdd, xfer);
692 
693 		if (status) {
694 			dev_err(&spi->dev,
695 				"I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
696 				xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
697 				(sdd->state & RXBUSY) ? 'f' : 'p',
698 				(sdd->state & TXBUSY) ? 'f' : 'p',
699 				xfer->len);
700 
701 			if (use_dma) {
702 				if (xfer->tx_buf && (sdd->state & TXBUSY))
703 					dmaengine_terminate_all(sdd->tx_dma.ch);
704 				if (xfer->rx_buf && (sdd->state & RXBUSY))
705 					dmaengine_terminate_all(sdd->rx_dma.ch);
706 			}
707 		} else {
708 			s3c64xx_flush_fifo(sdd);
709 		}
710 		if (target_len > 0) {
711 			target_len -= xfer->len;
712 
713 			if (xfer->tx_buf)
714 				xfer->tx_buf += xfer->len;
715 
716 			if (xfer->rx_buf)
717 				xfer->rx_buf += xfer->len;
718 
719 			if (target_len > fifo_len)
720 				xfer->len = fifo_len;
721 			else
722 				xfer->len = target_len;
723 		}
724 	} while (target_len > 0);
725 
726 	if (origin_len) {
727 		/* Restore original xfer buffers and length */
728 		xfer->tx_buf = tx_buf;
729 		xfer->rx_buf = rx_buf;
730 		xfer->len = origin_len;
731 	}
732 
733 	return status;
734 }
735 
736 static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
737 				struct spi_device *spi)
738 {
739 	struct s3c64xx_spi_csinfo *cs;
740 	struct device_node *slave_np, *data_np = NULL;
741 	u32 fb_delay = 0;
742 
743 	slave_np = spi->dev.of_node;
744 	if (!slave_np) {
745 		dev_err(&spi->dev, "device node not found\n");
746 		return ERR_PTR(-EINVAL);
747 	}
748 
749 	data_np = of_get_child_by_name(slave_np, "controller-data");
750 	if (!data_np) {
751 		dev_err(&spi->dev, "child node 'controller-data' not found\n");
752 		return ERR_PTR(-EINVAL);
753 	}
754 
755 	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
756 	if (!cs) {
757 		of_node_put(data_np);
758 		return ERR_PTR(-ENOMEM);
759 	}
760 
761 	of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
762 	cs->fb_delay = fb_delay;
763 	of_node_put(data_np);
764 	return cs;
765 }
766 
767 /*
768  * Here we only check the validity of requested configuration
769  * and save the configuration in a local data-structure.
770  * The controller is actually configured only just before we
771  * get a message to transfer.
772  */
773 static int s3c64xx_spi_setup(struct spi_device *spi)
774 {
775 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
776 	struct s3c64xx_spi_driver_data *sdd;
777 	int err;
778 
779 	sdd = spi_master_get_devdata(spi->master);
780 	if (spi->dev.of_node) {
781 		cs = s3c64xx_get_slave_ctrldata(spi);
782 		spi->controller_data = cs;
783 	} else if (cs) {
784 		/* On non-DT platforms the SPI core will set spi->cs_gpio
785 		 * to -ENOENT. The GPIO pin used to drive the chip select
786 		 * is defined by using platform data so spi->cs_gpio value
787 		 * has to be override to have the proper GPIO pin number.
788 		 */
789 		spi->cs_gpio = cs->line;
790 	}
791 
792 	if (IS_ERR_OR_NULL(cs)) {
793 		dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
794 		return -ENODEV;
795 	}
796 
797 	if (!spi_get_ctldata(spi)) {
798 		if (gpio_is_valid(spi->cs_gpio)) {
799 			err = gpio_request_one(spi->cs_gpio, GPIOF_OUT_INIT_HIGH,
800 					       dev_name(&spi->dev));
801 			if (err) {
802 				dev_err(&spi->dev,
803 					"Failed to get /CS gpio [%d]: %d\n",
804 					spi->cs_gpio, err);
805 				goto err_gpio_req;
806 			}
807 		}
808 
809 		spi_set_ctldata(spi, cs);
810 	}
811 
812 	pm_runtime_get_sync(&sdd->pdev->dev);
813 
814 	/* Check if we can provide the requested rate */
815 	if (!sdd->port_conf->clk_from_cmu) {
816 		u32 psr, speed;
817 
818 		/* Max possible */
819 		speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1);
820 
821 		if (spi->max_speed_hz > speed)
822 			spi->max_speed_hz = speed;
823 
824 		psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1;
825 		psr &= S3C64XX_SPI_PSR_MASK;
826 		if (psr == S3C64XX_SPI_PSR_MASK)
827 			psr--;
828 
829 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
830 		if (spi->max_speed_hz < speed) {
831 			if (psr+1 < S3C64XX_SPI_PSR_MASK) {
832 				psr++;
833 			} else {
834 				err = -EINVAL;
835 				goto setup_exit;
836 			}
837 		}
838 
839 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
840 		if (spi->max_speed_hz >= speed) {
841 			spi->max_speed_hz = speed;
842 		} else {
843 			dev_err(&spi->dev, "Can't set %dHz transfer speed\n",
844 				spi->max_speed_hz);
845 			err = -EINVAL;
846 			goto setup_exit;
847 		}
848 	}
849 
850 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
851 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
852 	s3c64xx_spi_set_cs(spi, false);
853 
854 	return 0;
855 
856 setup_exit:
857 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
858 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
859 	/* setup() returns with device de-selected */
860 	s3c64xx_spi_set_cs(spi, false);
861 
862 	if (gpio_is_valid(spi->cs_gpio))
863 		gpio_free(spi->cs_gpio);
864 	spi_set_ctldata(spi, NULL);
865 
866 err_gpio_req:
867 	if (spi->dev.of_node)
868 		kfree(cs);
869 
870 	return err;
871 }
872 
873 static void s3c64xx_spi_cleanup(struct spi_device *spi)
874 {
875 	struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
876 
877 	if (gpio_is_valid(spi->cs_gpio)) {
878 		gpio_free(spi->cs_gpio);
879 		if (spi->dev.of_node)
880 			kfree(cs);
881 		else {
882 			/* On non-DT platforms, the SPI core sets
883 			 * spi->cs_gpio to -ENOENT and .setup()
884 			 * overrides it with the GPIO pin value
885 			 * passed using platform data.
886 			 */
887 			spi->cs_gpio = -ENOENT;
888 		}
889 	}
890 
891 	spi_set_ctldata(spi, NULL);
892 }
893 
894 static irqreturn_t s3c64xx_spi_irq(int irq, void *data)
895 {
896 	struct s3c64xx_spi_driver_data *sdd = data;
897 	struct spi_master *spi = sdd->master;
898 	unsigned int val, clr = 0;
899 
900 	val = readl(sdd->regs + S3C64XX_SPI_STATUS);
901 
902 	if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) {
903 		clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR;
904 		dev_err(&spi->dev, "RX overrun\n");
905 	}
906 	if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) {
907 		clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR;
908 		dev_err(&spi->dev, "RX underrun\n");
909 	}
910 	if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) {
911 		clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR;
912 		dev_err(&spi->dev, "TX overrun\n");
913 	}
914 	if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) {
915 		clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
916 		dev_err(&spi->dev, "TX underrun\n");
917 	}
918 
919 	/* Clear the pending irq by setting and then clearing it */
920 	writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR);
921 	writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR);
922 
923 	return IRQ_HANDLED;
924 }
925 
926 static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd)
927 {
928 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
929 	void __iomem *regs = sdd->regs;
930 	unsigned int val;
931 
932 	sdd->cur_speed = 0;
933 
934 	if (sci->no_cs)
935 		writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
936 	else if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
937 		writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
938 
939 	/* Disable Interrupts - we use Polling if not DMA mode */
940 	writel(0, regs + S3C64XX_SPI_INT_EN);
941 
942 	if (!sdd->port_conf->clk_from_cmu)
943 		writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
944 				regs + S3C64XX_SPI_CLK_CFG);
945 	writel(0, regs + S3C64XX_SPI_MODE_CFG);
946 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
947 
948 	/* Clear any irq pending bits, should set and clear the bits */
949 	val = S3C64XX_SPI_PND_RX_OVERRUN_CLR |
950 		S3C64XX_SPI_PND_RX_UNDERRUN_CLR |
951 		S3C64XX_SPI_PND_TX_OVERRUN_CLR |
952 		S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
953 	writel(val, regs + S3C64XX_SPI_PENDING_CLR);
954 	writel(0, regs + S3C64XX_SPI_PENDING_CLR);
955 
956 	writel(0, regs + S3C64XX_SPI_SWAP_CFG);
957 
958 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
959 	val &= ~S3C64XX_SPI_MODE_4BURST;
960 	val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
961 	val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
962 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
963 
964 	s3c64xx_flush_fifo(sdd);
965 }
966 
967 #ifdef CONFIG_OF
968 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
969 {
970 	struct s3c64xx_spi_info *sci;
971 	u32 temp;
972 
973 	sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
974 	if (!sci)
975 		return ERR_PTR(-ENOMEM);
976 
977 	if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
978 		dev_warn(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
979 		sci->src_clk_nr = 0;
980 	} else {
981 		sci->src_clk_nr = temp;
982 	}
983 
984 	if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
985 		dev_warn(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
986 		sci->num_cs = 1;
987 	} else {
988 		sci->num_cs = temp;
989 	}
990 
991 	sci->no_cs = of_property_read_bool(dev->of_node, "no-cs-readback");
992 
993 	return sci;
994 }
995 #else
996 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
997 {
998 	return dev_get_platdata(dev);
999 }
1000 #endif
1001 
1002 static const struct of_device_id s3c64xx_spi_dt_match[];
1003 
1004 static inline struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
1005 						struct platform_device *pdev)
1006 {
1007 #ifdef CONFIG_OF
1008 	if (pdev->dev.of_node) {
1009 		const struct of_device_id *match;
1010 		match = of_match_node(s3c64xx_spi_dt_match, pdev->dev.of_node);
1011 		return (struct s3c64xx_spi_port_config *)match->data;
1012 	}
1013 #endif
1014 	return (struct s3c64xx_spi_port_config *)
1015 			 platform_get_device_id(pdev)->driver_data;
1016 }
1017 
1018 static int s3c64xx_spi_probe(struct platform_device *pdev)
1019 {
1020 	struct resource	*mem_res;
1021 	struct s3c64xx_spi_driver_data *sdd;
1022 	struct s3c64xx_spi_info *sci = dev_get_platdata(&pdev->dev);
1023 	struct spi_master *master;
1024 	int ret, irq;
1025 	char clk_name[16];
1026 
1027 	if (!sci && pdev->dev.of_node) {
1028 		sci = s3c64xx_spi_parse_dt(&pdev->dev);
1029 		if (IS_ERR(sci))
1030 			return PTR_ERR(sci);
1031 	}
1032 
1033 	if (!sci) {
1034 		dev_err(&pdev->dev, "platform_data missing!\n");
1035 		return -ENODEV;
1036 	}
1037 
1038 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1039 	if (mem_res == NULL) {
1040 		dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
1041 		return -ENXIO;
1042 	}
1043 
1044 	irq = platform_get_irq(pdev, 0);
1045 	if (irq < 0) {
1046 		dev_warn(&pdev->dev, "Failed to get IRQ: %d\n", irq);
1047 		return irq;
1048 	}
1049 
1050 	master = spi_alloc_master(&pdev->dev,
1051 				sizeof(struct s3c64xx_spi_driver_data));
1052 	if (master == NULL) {
1053 		dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
1054 		return -ENOMEM;
1055 	}
1056 
1057 	platform_set_drvdata(pdev, master);
1058 
1059 	sdd = spi_master_get_devdata(master);
1060 	sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
1061 	sdd->master = master;
1062 	sdd->cntrlr_info = sci;
1063 	sdd->pdev = pdev;
1064 	sdd->sfr_start = mem_res->start;
1065 	if (pdev->dev.of_node) {
1066 		ret = of_alias_get_id(pdev->dev.of_node, "spi");
1067 		if (ret < 0) {
1068 			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
1069 				ret);
1070 			goto err_deref_master;
1071 		}
1072 		sdd->port_id = ret;
1073 	} else {
1074 		sdd->port_id = pdev->id;
1075 	}
1076 
1077 	sdd->cur_bpw = 8;
1078 
1079 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
1080 	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
1081 
1082 	master->dev.of_node = pdev->dev.of_node;
1083 	master->bus_num = sdd->port_id;
1084 	master->setup = s3c64xx_spi_setup;
1085 	master->cleanup = s3c64xx_spi_cleanup;
1086 	master->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
1087 	master->prepare_message = s3c64xx_spi_prepare_message;
1088 	master->transfer_one = s3c64xx_spi_transfer_one;
1089 	master->num_chipselect = sci->num_cs;
1090 	master->dma_alignment = 8;
1091 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
1092 					SPI_BPW_MASK(8);
1093 	/* the spi->mode bits understood by this driver: */
1094 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1095 	master->auto_runtime_pm = true;
1096 	if (!is_polling(sdd))
1097 		master->can_dma = s3c64xx_spi_can_dma;
1098 
1099 	sdd->regs = devm_ioremap_resource(&pdev->dev, mem_res);
1100 	if (IS_ERR(sdd->regs)) {
1101 		ret = PTR_ERR(sdd->regs);
1102 		goto err_deref_master;
1103 	}
1104 
1105 	if (sci->cfg_gpio && sci->cfg_gpio()) {
1106 		dev_err(&pdev->dev, "Unable to config gpio\n");
1107 		ret = -EBUSY;
1108 		goto err_deref_master;
1109 	}
1110 
1111 	/* Setup clocks */
1112 	sdd->clk = devm_clk_get(&pdev->dev, "spi");
1113 	if (IS_ERR(sdd->clk)) {
1114 		dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
1115 		ret = PTR_ERR(sdd->clk);
1116 		goto err_deref_master;
1117 	}
1118 
1119 	ret = clk_prepare_enable(sdd->clk);
1120 	if (ret) {
1121 		dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
1122 		goto err_deref_master;
1123 	}
1124 
1125 	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
1126 	sdd->src_clk = devm_clk_get(&pdev->dev, clk_name);
1127 	if (IS_ERR(sdd->src_clk)) {
1128 		dev_err(&pdev->dev,
1129 			"Unable to acquire clock '%s'\n", clk_name);
1130 		ret = PTR_ERR(sdd->src_clk);
1131 		goto err_disable_clk;
1132 	}
1133 
1134 	ret = clk_prepare_enable(sdd->src_clk);
1135 	if (ret) {
1136 		dev_err(&pdev->dev, "Couldn't enable clock '%s'\n", clk_name);
1137 		goto err_disable_clk;
1138 	}
1139 
1140 	if (sdd->port_conf->clk_ioclk) {
1141 		sdd->ioclk = devm_clk_get(&pdev->dev, "spi_ioclk");
1142 		if (IS_ERR(sdd->ioclk)) {
1143 			dev_err(&pdev->dev, "Unable to acquire 'ioclk'\n");
1144 			ret = PTR_ERR(sdd->ioclk);
1145 			goto err_disable_src_clk;
1146 		}
1147 
1148 		ret = clk_prepare_enable(sdd->ioclk);
1149 		if (ret) {
1150 			dev_err(&pdev->dev, "Couldn't enable clock 'ioclk'\n");
1151 			goto err_disable_src_clk;
1152 		}
1153 	}
1154 
1155 	if (!is_polling(sdd)) {
1156 		/* Acquire DMA channels */
1157 		sdd->rx_dma.ch = dma_request_chan(&pdev->dev, "rx");
1158 		if (IS_ERR(sdd->rx_dma.ch)) {
1159 			dev_err(&pdev->dev, "Failed to get RX DMA channel\n");
1160 			ret = PTR_ERR(sdd->rx_dma.ch);
1161 			goto err_disable_io_clk;
1162 		}
1163 		sdd->tx_dma.ch = dma_request_chan(&pdev->dev, "tx");
1164 		if (IS_ERR(sdd->tx_dma.ch)) {
1165 			dev_err(&pdev->dev, "Failed to get TX DMA channel\n");
1166 			ret = PTR_ERR(sdd->tx_dma.ch);
1167 			goto err_release_rx_dma;
1168 		}
1169 	}
1170 
1171 	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1172 	pm_runtime_use_autosuspend(&pdev->dev);
1173 	pm_runtime_set_active(&pdev->dev);
1174 	pm_runtime_enable(&pdev->dev);
1175 	pm_runtime_get_sync(&pdev->dev);
1176 
1177 	/* Setup Deufult Mode */
1178 	s3c64xx_spi_hwinit(sdd);
1179 
1180 	spin_lock_init(&sdd->lock);
1181 	init_completion(&sdd->xfer_completion);
1182 
1183 	ret = devm_request_irq(&pdev->dev, irq, s3c64xx_spi_irq, 0,
1184 				"spi-s3c64xx", sdd);
1185 	if (ret != 0) {
1186 		dev_err(&pdev->dev, "Failed to request IRQ %d: %d\n",
1187 			irq, ret);
1188 		goto err_pm_put;
1189 	}
1190 
1191 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1192 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1193 	       sdd->regs + S3C64XX_SPI_INT_EN);
1194 
1195 	ret = devm_spi_register_master(&pdev->dev, master);
1196 	if (ret != 0) {
1197 		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
1198 		goto err_pm_put;
1199 	}
1200 
1201 	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",
1202 					sdd->port_id, master->num_chipselect);
1203 	dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\n",
1204 					mem_res, (FIFO_LVL_MASK(sdd) >> 1) + 1);
1205 
1206 	pm_runtime_mark_last_busy(&pdev->dev);
1207 	pm_runtime_put_autosuspend(&pdev->dev);
1208 
1209 	return 0;
1210 
1211 err_pm_put:
1212 	pm_runtime_put_noidle(&pdev->dev);
1213 	pm_runtime_disable(&pdev->dev);
1214 	pm_runtime_set_suspended(&pdev->dev);
1215 
1216 	if (!is_polling(sdd))
1217 		dma_release_channel(sdd->tx_dma.ch);
1218 err_release_rx_dma:
1219 	if (!is_polling(sdd))
1220 		dma_release_channel(sdd->rx_dma.ch);
1221 err_disable_io_clk:
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 	if (!is_polling(sdd)) {
1243 		dma_release_channel(sdd->rx_dma.ch);
1244 		dma_release_channel(sdd->tx_dma.ch);
1245 	}
1246 
1247 	clk_disable_unprepare(sdd->ioclk);
1248 
1249 	clk_disable_unprepare(sdd->src_clk);
1250 
1251 	clk_disable_unprepare(sdd->clk);
1252 
1253 	pm_runtime_put_noidle(&pdev->dev);
1254 	pm_runtime_disable(&pdev->dev);
1255 	pm_runtime_set_suspended(&pdev->dev);
1256 
1257 	return 0;
1258 }
1259 
1260 #ifdef CONFIG_PM_SLEEP
1261 static int s3c64xx_spi_suspend(struct device *dev)
1262 {
1263 	struct spi_master *master = dev_get_drvdata(dev);
1264 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1265 
1266 	int ret = spi_master_suspend(master);
1267 	if (ret)
1268 		return ret;
1269 
1270 	ret = pm_runtime_force_suspend(dev);
1271 	if (ret < 0)
1272 		return ret;
1273 
1274 	sdd->cur_speed = 0; /* Output Clock is stopped */
1275 
1276 	return 0;
1277 }
1278 
1279 static int s3c64xx_spi_resume(struct device *dev)
1280 {
1281 	struct spi_master *master = dev_get_drvdata(dev);
1282 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1283 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1284 	int ret;
1285 
1286 	if (sci->cfg_gpio)
1287 		sci->cfg_gpio();
1288 
1289 	ret = pm_runtime_force_resume(dev);
1290 	if (ret < 0)
1291 		return ret;
1292 
1293 	return spi_master_resume(master);
1294 }
1295 #endif /* CONFIG_PM_SLEEP */
1296 
1297 #ifdef CONFIG_PM
1298 static int s3c64xx_spi_runtime_suspend(struct device *dev)
1299 {
1300 	struct spi_master *master = dev_get_drvdata(dev);
1301 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1302 
1303 	clk_disable_unprepare(sdd->clk);
1304 	clk_disable_unprepare(sdd->src_clk);
1305 	clk_disable_unprepare(sdd->ioclk);
1306 
1307 	return 0;
1308 }
1309 
1310 static int s3c64xx_spi_runtime_resume(struct device *dev)
1311 {
1312 	struct spi_master *master = dev_get_drvdata(dev);
1313 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1314 	int ret;
1315 
1316 	if (sdd->port_conf->clk_ioclk) {
1317 		ret = clk_prepare_enable(sdd->ioclk);
1318 		if (ret != 0)
1319 			return ret;
1320 	}
1321 
1322 	ret = clk_prepare_enable(sdd->src_clk);
1323 	if (ret != 0)
1324 		goto err_disable_ioclk;
1325 
1326 	ret = clk_prepare_enable(sdd->clk);
1327 	if (ret != 0)
1328 		goto err_disable_src_clk;
1329 
1330 	s3c64xx_spi_hwinit(sdd);
1331 
1332 	return 0;
1333 
1334 err_disable_src_clk:
1335 	clk_disable_unprepare(sdd->src_clk);
1336 err_disable_ioclk:
1337 	clk_disable_unprepare(sdd->ioclk);
1338 
1339 	return ret;
1340 }
1341 #endif /* CONFIG_PM */
1342 
1343 static const struct dev_pm_ops s3c64xx_spi_pm = {
1344 	SET_SYSTEM_SLEEP_PM_OPS(s3c64xx_spi_suspend, s3c64xx_spi_resume)
1345 	SET_RUNTIME_PM_OPS(s3c64xx_spi_runtime_suspend,
1346 			   s3c64xx_spi_runtime_resume, NULL)
1347 };
1348 
1349 static struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
1350 	.fifo_lvl_mask	= { 0x7f },
1351 	.rx_lvl_offset	= 13,
1352 	.tx_st_done	= 21,
1353 	.high_speed	= true,
1354 };
1355 
1356 static struct s3c64xx_spi_port_config s3c6410_spi_port_config = {
1357 	.fifo_lvl_mask	= { 0x7f, 0x7F },
1358 	.rx_lvl_offset	= 13,
1359 	.tx_st_done	= 21,
1360 };
1361 
1362 static struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
1363 	.fifo_lvl_mask	= { 0x1ff, 0x7F },
1364 	.rx_lvl_offset	= 15,
1365 	.tx_st_done	= 25,
1366 	.high_speed	= true,
1367 };
1368 
1369 static struct s3c64xx_spi_port_config exynos4_spi_port_config = {
1370 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F },
1371 	.rx_lvl_offset	= 15,
1372 	.tx_st_done	= 25,
1373 	.high_speed	= true,
1374 	.clk_from_cmu	= true,
1375 };
1376 
1377 static struct s3c64xx_spi_port_config exynos7_spi_port_config = {
1378 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},
1379 	.rx_lvl_offset	= 15,
1380 	.tx_st_done	= 25,
1381 	.high_speed	= true,
1382 	.clk_from_cmu	= true,
1383 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1384 };
1385 
1386 static struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
1387 	.fifo_lvl_mask	= { 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff},
1388 	.rx_lvl_offset	= 15,
1389 	.tx_st_done	= 25,
1390 	.high_speed	= true,
1391 	.clk_from_cmu	= true,
1392 	.clk_ioclk	= true,
1393 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1394 };
1395 
1396 static const struct platform_device_id s3c64xx_spi_driver_ids[] = {
1397 	{
1398 		.name		= "s3c2443-spi",
1399 		.driver_data	= (kernel_ulong_t)&s3c2443_spi_port_config,
1400 	}, {
1401 		.name		= "s3c6410-spi",
1402 		.driver_data	= (kernel_ulong_t)&s3c6410_spi_port_config,
1403 	},
1404 	{ },
1405 };
1406 
1407 static const struct of_device_id s3c64xx_spi_dt_match[] = {
1408 	{ .compatible = "samsung,s3c2443-spi",
1409 			.data = (void *)&s3c2443_spi_port_config,
1410 	},
1411 	{ .compatible = "samsung,s3c6410-spi",
1412 			.data = (void *)&s3c6410_spi_port_config,
1413 	},
1414 	{ .compatible = "samsung,s5pv210-spi",
1415 			.data = (void *)&s5pv210_spi_port_config,
1416 	},
1417 	{ .compatible = "samsung,exynos4210-spi",
1418 			.data = (void *)&exynos4_spi_port_config,
1419 	},
1420 	{ .compatible = "samsung,exynos7-spi",
1421 			.data = (void *)&exynos7_spi_port_config,
1422 	},
1423 	{ .compatible = "samsung,exynos5433-spi",
1424 			.data = (void *)&exynos5433_spi_port_config,
1425 	},
1426 	{ },
1427 };
1428 MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
1429 
1430 static struct platform_driver s3c64xx_spi_driver = {
1431 	.driver = {
1432 		.name	= "s3c64xx-spi",
1433 		.pm = &s3c64xx_spi_pm,
1434 		.of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
1435 	},
1436 	.probe = s3c64xx_spi_probe,
1437 	.remove = s3c64xx_spi_remove,
1438 	.id_table = s3c64xx_spi_driver_ids,
1439 };
1440 MODULE_ALIAS("platform:s3c64xx-spi");
1441 
1442 module_platform_driver(s3c64xx_spi_driver);
1443 
1444 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1445 MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1446 MODULE_LICENSE("GPL");
1447