xref: /openbmc/linux/drivers/spi/spi-s3c64xx.c (revision 1e726951)
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/of.h>
17 #include <linux/of_device.h>
18 
19 #include <linux/platform_data/spi-s3c64xx.h>
20 
21 #define MAX_SPI_PORTS		12
22 #define S3C64XX_SPI_QUIRK_POLL		(1 << 0)
23 #define S3C64XX_SPI_QUIRK_CS_AUTO	(1 << 1)
24 #define AUTOSUSPEND_TIMEOUT	2000
25 
26 /* Registers and bit-fields */
27 
28 #define S3C64XX_SPI_CH_CFG		0x00
29 #define S3C64XX_SPI_CLK_CFG		0x04
30 #define S3C64XX_SPI_MODE_CFG		0x08
31 #define S3C64XX_SPI_CS_REG		0x0C
32 #define S3C64XX_SPI_INT_EN		0x10
33 #define S3C64XX_SPI_STATUS		0x14
34 #define S3C64XX_SPI_TX_DATA		0x18
35 #define S3C64XX_SPI_RX_DATA		0x1C
36 #define S3C64XX_SPI_PACKET_CNT		0x20
37 #define S3C64XX_SPI_PENDING_CLR		0x24
38 #define S3C64XX_SPI_SWAP_CFG		0x28
39 #define S3C64XX_SPI_FB_CLK		0x2C
40 
41 #define S3C64XX_SPI_CH_HS_EN		(1<<6)	/* High Speed Enable */
42 #define S3C64XX_SPI_CH_SW_RST		(1<<5)
43 #define S3C64XX_SPI_CH_SLAVE		(1<<4)
44 #define S3C64XX_SPI_CPOL_L		(1<<3)
45 #define S3C64XX_SPI_CPHA_B		(1<<2)
46 #define S3C64XX_SPI_CH_RXCH_ON		(1<<1)
47 #define S3C64XX_SPI_CH_TXCH_ON		(1<<0)
48 
49 #define S3C64XX_SPI_CLKSEL_SRCMSK	(3<<9)
50 #define S3C64XX_SPI_CLKSEL_SRCSHFT	9
51 #define S3C64XX_SPI_ENCLK_ENABLE	(1<<8)
52 #define S3C64XX_SPI_PSR_MASK		0xff
53 
54 #define S3C64XX_SPI_MODE_CH_TSZ_BYTE		(0<<29)
55 #define S3C64XX_SPI_MODE_CH_TSZ_HALFWORD	(1<<29)
56 #define S3C64XX_SPI_MODE_CH_TSZ_WORD		(2<<29)
57 #define S3C64XX_SPI_MODE_CH_TSZ_MASK		(3<<29)
58 #define S3C64XX_SPI_MODE_BUS_TSZ_BYTE		(0<<17)
59 #define S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD	(1<<17)
60 #define S3C64XX_SPI_MODE_BUS_TSZ_WORD		(2<<17)
61 #define S3C64XX_SPI_MODE_BUS_TSZ_MASK		(3<<17)
62 #define S3C64XX_SPI_MODE_SELF_LOOPBACK		(1<<3)
63 #define S3C64XX_SPI_MODE_RXDMA_ON		(1<<2)
64 #define S3C64XX_SPI_MODE_TXDMA_ON		(1<<1)
65 #define S3C64XX_SPI_MODE_4BURST			(1<<0)
66 
67 #define S3C64XX_SPI_CS_NSC_CNT_2		(2<<4)
68 #define S3C64XX_SPI_CS_AUTO			(1<<1)
69 #define S3C64XX_SPI_CS_SIG_INACT		(1<<0)
70 
71 #define S3C64XX_SPI_INT_TRAILING_EN		(1<<6)
72 #define S3C64XX_SPI_INT_RX_OVERRUN_EN		(1<<5)
73 #define S3C64XX_SPI_INT_RX_UNDERRUN_EN		(1<<4)
74 #define S3C64XX_SPI_INT_TX_OVERRUN_EN		(1<<3)
75 #define S3C64XX_SPI_INT_TX_UNDERRUN_EN		(1<<2)
76 #define S3C64XX_SPI_INT_RX_FIFORDY_EN		(1<<1)
77 #define S3C64XX_SPI_INT_TX_FIFORDY_EN		(1<<0)
78 
79 #define S3C64XX_SPI_ST_RX_OVERRUN_ERR		(1<<5)
80 #define S3C64XX_SPI_ST_RX_UNDERRUN_ERR		(1<<4)
81 #define S3C64XX_SPI_ST_TX_OVERRUN_ERR		(1<<3)
82 #define S3C64XX_SPI_ST_TX_UNDERRUN_ERR		(1<<2)
83 #define S3C64XX_SPI_ST_RX_FIFORDY		(1<<1)
84 #define S3C64XX_SPI_ST_TX_FIFORDY		(1<<0)
85 
86 #define S3C64XX_SPI_PACKET_CNT_EN		(1<<16)
87 #define S3C64XX_SPI_PACKET_CNT_MASK		GENMASK(15, 0)
88 
89 #define S3C64XX_SPI_PND_TX_UNDERRUN_CLR		(1<<4)
90 #define S3C64XX_SPI_PND_TX_OVERRUN_CLR		(1<<3)
91 #define S3C64XX_SPI_PND_RX_UNDERRUN_CLR		(1<<2)
92 #define S3C64XX_SPI_PND_RX_OVERRUN_CLR		(1<<1)
93 #define S3C64XX_SPI_PND_TRAILING_CLR		(1<<0)
94 
95 #define S3C64XX_SPI_SWAP_RX_HALF_WORD		(1<<7)
96 #define S3C64XX_SPI_SWAP_RX_BYTE		(1<<6)
97 #define S3C64XX_SPI_SWAP_RX_BIT			(1<<5)
98 #define S3C64XX_SPI_SWAP_RX_EN			(1<<4)
99 #define S3C64XX_SPI_SWAP_TX_HALF_WORD		(1<<3)
100 #define S3C64XX_SPI_SWAP_TX_BYTE		(1<<2)
101 #define S3C64XX_SPI_SWAP_TX_BIT			(1<<1)
102 #define S3C64XX_SPI_SWAP_TX_EN			(1<<0)
103 
104 #define S3C64XX_SPI_FBCLK_MSK			(3<<0)
105 
106 #define FIFO_LVL_MASK(i) ((i)->port_conf->fifo_lvl_mask[i->port_id])
107 #define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & \
108 				(1 << (i)->port_conf->tx_st_done)) ? 1 : 0)
109 #define TX_FIFO_LVL(v, i) (((v) >> 6) & FIFO_LVL_MASK(i))
110 #define RX_FIFO_LVL(v, i) (((v) >> (i)->port_conf->rx_lvl_offset) & \
111 					FIFO_LVL_MASK(i))
112 
113 #define S3C64XX_SPI_MAX_TRAILCNT	0x3ff
114 #define S3C64XX_SPI_TRAILCNT_OFF	19
115 
116 #define S3C64XX_SPI_TRAILCNT		S3C64XX_SPI_MAX_TRAILCNT
117 
118 #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
119 #define is_polling(x)	(x->port_conf->quirks & S3C64XX_SPI_QUIRK_POLL)
120 
121 #define RXBUSY    (1<<2)
122 #define TXBUSY    (1<<3)
123 
124 struct s3c64xx_spi_dma_data {
125 	struct dma_chan *ch;
126 	dma_cookie_t cookie;
127 	enum dma_transfer_direction direction;
128 };
129 
130 /**
131  * struct s3c64xx_spi_port_config - SPI Controller hardware info
132  * @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
133  * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
134  * @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
135  * @clk_div: Internal clock divider
136  * @quirks: Bitmask of known quirks
137  * @high_speed: True, if the controller supports HIGH_SPEED_EN bit.
138  * @clk_from_cmu: True, if the controller does not include a clock mux and
139  *	prescaler unit.
140  * @clk_ioclk: True if clock is present on this device
141  * @has_loopback: True if loopback mode can be supported
142  *
143  * The Samsung s3c64xx SPI controller are used on various Samsung SoC's but
144  * differ in some aspects such as the size of the fifo and spi bus clock
145  * setup. Such differences are specified to the driver using this structure
146  * which is provided as driver data to the driver.
147  */
148 struct s3c64xx_spi_port_config {
149 	int	fifo_lvl_mask[MAX_SPI_PORTS];
150 	int	rx_lvl_offset;
151 	int	tx_st_done;
152 	int	quirks;
153 	int	clk_div;
154 	bool	high_speed;
155 	bool	clk_from_cmu;
156 	bool	clk_ioclk;
157 	bool	has_loopback;
158 };
159 
160 /**
161  * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
162  * @clk: Pointer to the spi clock.
163  * @src_clk: Pointer to the clock used to generate SPI signals.
164  * @ioclk: Pointer to the i/o clock between master and slave
165  * @pdev: Pointer to device's platform device data
166  * @master: Pointer to the SPI Protocol master.
167  * @cntrlr_info: Platform specific data for the controller this driver manages.
168  * @lock: Controller specific lock.
169  * @state: Set of FLAGS to indicate status.
170  * @sfr_start: BUS address of SPI controller regs.
171  * @regs: Pointer to ioremap'ed controller registers.
172  * @xfer_completion: To indicate completion of xfer task.
173  * @cur_mode: Stores the active configuration of the controller.
174  * @cur_bpw: Stores the active bits per word settings.
175  * @cur_speed: Current clock speed
176  * @rx_dma: Local receive DMA data (e.g. chan and direction)
177  * @tx_dma: Local transmit DMA data (e.g. chan and direction)
178  * @port_conf: Local SPI port configuartion data
179  * @port_id: Port identification number
180  */
181 struct s3c64xx_spi_driver_data {
182 	void __iomem                    *regs;
183 	struct clk                      *clk;
184 	struct clk                      *src_clk;
185 	struct clk                      *ioclk;
186 	struct platform_device          *pdev;
187 	struct spi_master               *master;
188 	struct s3c64xx_spi_info         *cntrlr_info;
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 	const struct s3c64xx_spi_port_config	*port_conf;
198 	unsigned int			port_id;
199 };
200 
201 static void s3c64xx_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 int 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 	int ret;
284 
285 	memset(&config, 0, sizeof(config));
286 
287 	if (dma->direction == DMA_DEV_TO_MEM) {
288 		sdd = container_of((void *)dma,
289 			struct s3c64xx_spi_driver_data, rx_dma);
290 		config.direction = dma->direction;
291 		config.src_addr = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
292 		config.src_addr_width = sdd->cur_bpw / 8;
293 		config.src_maxburst = 1;
294 		dmaengine_slave_config(dma->ch, &config);
295 	} else {
296 		sdd = container_of((void *)dma,
297 			struct s3c64xx_spi_driver_data, tx_dma);
298 		config.direction = dma->direction;
299 		config.dst_addr = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
300 		config.dst_addr_width = sdd->cur_bpw / 8;
301 		config.dst_maxburst = 1;
302 		dmaengine_slave_config(dma->ch, &config);
303 	}
304 
305 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
306 				       dma->direction, DMA_PREP_INTERRUPT);
307 	if (!desc) {
308 		dev_err(&sdd->pdev->dev, "unable to prepare %s scatterlist",
309 			dma->direction == DMA_DEV_TO_MEM ? "rx" : "tx");
310 		return -ENOMEM;
311 	}
312 
313 	desc->callback = s3c64xx_spi_dmacb;
314 	desc->callback_param = dma;
315 
316 	dma->cookie = dmaengine_submit(desc);
317 	ret = dma_submit_error(dma->cookie);
318 	if (ret) {
319 		dev_err(&sdd->pdev->dev, "DMA submission failed");
320 		return -EIO;
321 	}
322 
323 	dma_async_issue_pending(dma->ch);
324 	return 0;
325 }
326 
327 static void s3c64xx_spi_set_cs(struct spi_device *spi, bool enable)
328 {
329 	struct s3c64xx_spi_driver_data *sdd =
330 					spi_master_get_devdata(spi->master);
331 
332 	if (sdd->cntrlr_info->no_cs)
333 		return;
334 
335 	if (enable) {
336 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO)) {
337 			writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
338 		} else {
339 			u32 ssel = readl(sdd->regs + S3C64XX_SPI_CS_REG);
340 
341 			ssel |= (S3C64XX_SPI_CS_AUTO |
342 						S3C64XX_SPI_CS_NSC_CNT_2);
343 			writel(ssel, sdd->regs + S3C64XX_SPI_CS_REG);
344 		}
345 	} else {
346 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
347 			writel(S3C64XX_SPI_CS_SIG_INACT,
348 			       sdd->regs + S3C64XX_SPI_CS_REG);
349 	}
350 }
351 
352 static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
353 {
354 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
355 
356 	if (is_polling(sdd))
357 		return 0;
358 
359 	/* Requests DMA channels */
360 	sdd->rx_dma.ch = dma_request_chan(&sdd->pdev->dev, "rx");
361 	if (IS_ERR(sdd->rx_dma.ch)) {
362 		dev_err(&sdd->pdev->dev, "Failed to get RX DMA channel\n");
363 		sdd->rx_dma.ch = NULL;
364 		return 0;
365 	}
366 
367 	sdd->tx_dma.ch = dma_request_chan(&sdd->pdev->dev, "tx");
368 	if (IS_ERR(sdd->tx_dma.ch)) {
369 		dev_err(&sdd->pdev->dev, "Failed to get TX DMA channel\n");
370 		dma_release_channel(sdd->rx_dma.ch);
371 		sdd->tx_dma.ch = NULL;
372 		sdd->rx_dma.ch = NULL;
373 		return 0;
374 	}
375 
376 	spi->dma_rx = sdd->rx_dma.ch;
377 	spi->dma_tx = sdd->tx_dma.ch;
378 
379 	return 0;
380 }
381 
382 static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
383 {
384 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
385 
386 	if (is_polling(sdd))
387 		return 0;
388 
389 	/* Releases DMA channels if they are allocated */
390 	if (sdd->rx_dma.ch && sdd->tx_dma.ch) {
391 		dma_release_channel(sdd->rx_dma.ch);
392 		dma_release_channel(sdd->tx_dma.ch);
393 		sdd->rx_dma.ch = NULL;
394 		sdd->tx_dma.ch = NULL;
395 	}
396 
397 	return 0;
398 }
399 
400 static bool s3c64xx_spi_can_dma(struct spi_master *master,
401 				struct spi_device *spi,
402 				struct spi_transfer *xfer)
403 {
404 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
405 
406 	if (sdd->rx_dma.ch && sdd->tx_dma.ch) {
407 		return xfer->len > (FIFO_LVL_MASK(sdd) >> 1) + 1;
408 	} else {
409 		return false;
410 	}
411 
412 }
413 
414 static int s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
415 				    struct spi_transfer *xfer, int dma_mode)
416 {
417 	void __iomem *regs = sdd->regs;
418 	u32 modecfg, chcfg;
419 	int ret = 0;
420 
421 	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
422 	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
423 
424 	chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
425 	chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
426 
427 	if (dma_mode) {
428 		chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
429 	} else {
430 		/* Always shift in data in FIFO, even if xfer is Tx only,
431 		 * this helps setting PCKT_CNT value for generating clocks
432 		 * as exactly needed.
433 		 */
434 		chcfg |= S3C64XX_SPI_CH_RXCH_ON;
435 		writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
436 					| S3C64XX_SPI_PACKET_CNT_EN,
437 					regs + S3C64XX_SPI_PACKET_CNT);
438 	}
439 
440 	if (xfer->tx_buf != NULL) {
441 		sdd->state |= TXBUSY;
442 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
443 		if (dma_mode) {
444 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
445 			ret = prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
446 		} else {
447 			switch (sdd->cur_bpw) {
448 			case 32:
449 				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
450 					xfer->tx_buf, xfer->len / 4);
451 				break;
452 			case 16:
453 				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
454 					xfer->tx_buf, xfer->len / 2);
455 				break;
456 			default:
457 				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
458 					xfer->tx_buf, xfer->len);
459 				break;
460 			}
461 		}
462 	}
463 
464 	if (xfer->rx_buf != NULL) {
465 		sdd->state |= RXBUSY;
466 
467 		if (sdd->port_conf->high_speed && sdd->cur_speed >= 30000000UL
468 					&& !(sdd->cur_mode & SPI_CPHA))
469 			chcfg |= S3C64XX_SPI_CH_HS_EN;
470 
471 		if (dma_mode) {
472 			modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
473 			chcfg |= S3C64XX_SPI_CH_RXCH_ON;
474 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
475 					| S3C64XX_SPI_PACKET_CNT_EN,
476 					regs + S3C64XX_SPI_PACKET_CNT);
477 			ret = prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
478 		}
479 	}
480 
481 	if (ret)
482 		return ret;
483 
484 	writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
485 	writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
486 
487 	return 0;
488 }
489 
490 static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
491 					int timeout_ms)
492 {
493 	void __iomem *regs = sdd->regs;
494 	unsigned long val = 1;
495 	u32 status;
496 
497 	/* max fifo depth available */
498 	u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
499 
500 	if (timeout_ms)
501 		val = msecs_to_loops(timeout_ms);
502 
503 	do {
504 		status = readl(regs + S3C64XX_SPI_STATUS);
505 	} while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
506 
507 	/* return the actual received data length */
508 	return RX_FIFO_LVL(status, sdd);
509 }
510 
511 static int s3c64xx_wait_for_dma(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 ms;
518 
519 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
520 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
521 	ms += 30;               /* some tolerance */
522 	ms = max(ms, 100);      /* minimum timeout */
523 
524 	val = msecs_to_jiffies(ms) + 10;
525 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
526 
527 	/*
528 	 * If the previous xfer was completed within timeout, then
529 	 * proceed further else return -EIO.
530 	 * DmaTx returns after simply writing data in the FIFO,
531 	 * w/o waiting for real transmission on the bus to finish.
532 	 * DmaRx returns only after Dma read data from FIFO which
533 	 * needs bus transmission to finish, so we don't worry if
534 	 * Xfer involved Rx(with or without Tx).
535 	 */
536 	if (val && !xfer->rx_buf) {
537 		val = msecs_to_loops(10);
538 		status = readl(regs + S3C64XX_SPI_STATUS);
539 		while ((TX_FIFO_LVL(status, sdd)
540 			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
541 		       && --val) {
542 			cpu_relax();
543 			status = readl(regs + S3C64XX_SPI_STATUS);
544 		}
545 
546 	}
547 
548 	/* If timed out while checking rx/tx status return error */
549 	if (!val)
550 		return -EIO;
551 
552 	return 0;
553 }
554 
555 static int s3c64xx_wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
556 				struct spi_transfer *xfer)
557 {
558 	void __iomem *regs = sdd->regs;
559 	unsigned long val;
560 	u32 status;
561 	int loops;
562 	u32 cpy_len;
563 	u8 *buf;
564 	int ms;
565 
566 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
567 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
568 	ms += 10; /* some tolerance */
569 
570 	val = msecs_to_loops(ms);
571 	do {
572 		status = readl(regs + S3C64XX_SPI_STATUS);
573 	} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
574 
575 	if (!val)
576 		return -EIO;
577 
578 	/* If it was only Tx */
579 	if (!xfer->rx_buf) {
580 		sdd->state &= ~TXBUSY;
581 		return 0;
582 	}
583 
584 	/*
585 	 * If the receive length is bigger than the controller fifo
586 	 * size, calculate the loops and read the fifo as many times.
587 	 * loops = length / max fifo size (calculated by using the
588 	 * fifo mask).
589 	 * For any size less than the fifo size the below code is
590 	 * executed atleast once.
591 	 */
592 	loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
593 	buf = xfer->rx_buf;
594 	do {
595 		/* wait for data to be received in the fifo */
596 		cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
597 						       (loops ? ms : 0));
598 
599 		switch (sdd->cur_bpw) {
600 		case 32:
601 			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
602 				     buf, cpy_len / 4);
603 			break;
604 		case 16:
605 			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
606 				     buf, cpy_len / 2);
607 			break;
608 		default:
609 			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
610 				    buf, cpy_len);
611 			break;
612 		}
613 
614 		buf = buf + cpy_len;
615 	} while (loops--);
616 	sdd->state &= ~RXBUSY;
617 
618 	return 0;
619 }
620 
621 static int s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
622 {
623 	void __iomem *regs = sdd->regs;
624 	int ret;
625 	u32 val;
626 	int div = sdd->port_conf->clk_div;
627 
628 	/* Disable Clock */
629 	if (!sdd->port_conf->clk_from_cmu) {
630 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
631 		val &= ~S3C64XX_SPI_ENCLK_ENABLE;
632 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
633 	}
634 
635 	/* Set Polarity and Phase */
636 	val = readl(regs + S3C64XX_SPI_CH_CFG);
637 	val &= ~(S3C64XX_SPI_CH_SLAVE |
638 			S3C64XX_SPI_CPOL_L |
639 			S3C64XX_SPI_CPHA_B);
640 
641 	if (sdd->cur_mode & SPI_CPOL)
642 		val |= S3C64XX_SPI_CPOL_L;
643 
644 	if (sdd->cur_mode & SPI_CPHA)
645 		val |= S3C64XX_SPI_CPHA_B;
646 
647 	writel(val, regs + S3C64XX_SPI_CH_CFG);
648 
649 	/* Set Channel & DMA Mode */
650 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
651 	val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
652 			| S3C64XX_SPI_MODE_CH_TSZ_MASK);
653 
654 	switch (sdd->cur_bpw) {
655 	case 32:
656 		val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
657 		val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;
658 		break;
659 	case 16:
660 		val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
661 		val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;
662 		break;
663 	default:
664 		val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
665 		val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;
666 		break;
667 	}
668 
669 	if ((sdd->cur_mode & SPI_LOOP) && sdd->port_conf->has_loopback)
670 		val |= S3C64XX_SPI_MODE_SELF_LOOPBACK;
671 
672 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
673 
674 	if (sdd->port_conf->clk_from_cmu) {
675 		ret = clk_set_rate(sdd->src_clk, sdd->cur_speed * div);
676 		if (ret)
677 			return ret;
678 		sdd->cur_speed = clk_get_rate(sdd->src_clk) / div;
679 	} else {
680 		/* Configure Clock */
681 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
682 		val &= ~S3C64XX_SPI_PSR_MASK;
683 		val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / div - 1)
684 				& S3C64XX_SPI_PSR_MASK);
685 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
686 
687 		/* Enable Clock */
688 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
689 		val |= S3C64XX_SPI_ENCLK_ENABLE;
690 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
691 	}
692 
693 	return 0;
694 }
695 
696 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
697 
698 static int s3c64xx_spi_prepare_message(struct spi_master *master,
699 				       struct spi_message *msg)
700 {
701 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
702 	struct spi_device *spi = msg->spi;
703 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
704 
705 	/* Configure feedback delay */
706 	if (!cs)
707 		/* No delay if not defined */
708 		writel(0, sdd->regs + S3C64XX_SPI_FB_CLK);
709 	else
710 		writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
711 
712 	return 0;
713 }
714 
715 static size_t s3c64xx_spi_max_transfer_size(struct spi_device *spi)
716 {
717 	struct spi_controller *ctlr = spi->controller;
718 
719 	return ctlr->can_dma ? S3C64XX_SPI_PACKET_CNT_MASK : SIZE_MAX;
720 }
721 
722 static int s3c64xx_spi_transfer_one(struct spi_master *master,
723 				    struct spi_device *spi,
724 				    struct spi_transfer *xfer)
725 {
726 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
727 	const unsigned int fifo_len = (FIFO_LVL_MASK(sdd) >> 1) + 1;
728 	const void *tx_buf = NULL;
729 	void *rx_buf = NULL;
730 	int target_len = 0, origin_len = 0;
731 	int use_dma = 0;
732 	int status;
733 	u32 speed;
734 	u8 bpw;
735 	unsigned long flags;
736 
737 	reinit_completion(&sdd->xfer_completion);
738 
739 	/* Only BPW and Speed may change across transfers */
740 	bpw = xfer->bits_per_word;
741 	speed = xfer->speed_hz;
742 
743 	if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
744 		sdd->cur_bpw = bpw;
745 		sdd->cur_speed = speed;
746 		sdd->cur_mode = spi->mode;
747 		status = s3c64xx_spi_config(sdd);
748 		if (status)
749 			return status;
750 	}
751 
752 	if (!is_polling(sdd) && (xfer->len > fifo_len) &&
753 	    sdd->rx_dma.ch && sdd->tx_dma.ch) {
754 		use_dma = 1;
755 
756 	} else if (xfer->len > fifo_len) {
757 		tx_buf = xfer->tx_buf;
758 		rx_buf = xfer->rx_buf;
759 		origin_len = xfer->len;
760 
761 		target_len = xfer->len;
762 		if (xfer->len > fifo_len)
763 			xfer->len = fifo_len;
764 	}
765 
766 	do {
767 		spin_lock_irqsave(&sdd->lock, flags);
768 
769 		/* Pending only which is to be done */
770 		sdd->state &= ~RXBUSY;
771 		sdd->state &= ~TXBUSY;
772 
773 		/* Start the signals */
774 		s3c64xx_spi_set_cs(spi, true);
775 
776 		status = s3c64xx_enable_datapath(sdd, xfer, use_dma);
777 
778 		spin_unlock_irqrestore(&sdd->lock, flags);
779 
780 		if (status) {
781 			dev_err(&spi->dev, "failed to enable data path for transfer: %d\n", status);
782 			break;
783 		}
784 
785 		if (use_dma)
786 			status = s3c64xx_wait_for_dma(sdd, xfer);
787 		else
788 			status = s3c64xx_wait_for_pio(sdd, xfer);
789 
790 		if (status) {
791 			dev_err(&spi->dev,
792 				"I/O Error: rx-%d tx-%d rx-%c tx-%c len-%d dma-%d res-(%d)\n",
793 				xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
794 				(sdd->state & RXBUSY) ? 'f' : 'p',
795 				(sdd->state & TXBUSY) ? 'f' : 'p',
796 				xfer->len, use_dma ? 1 : 0, status);
797 
798 			if (use_dma) {
799 				struct dma_tx_state s;
800 
801 				if (xfer->tx_buf && (sdd->state & TXBUSY)) {
802 					dmaengine_pause(sdd->tx_dma.ch);
803 					dmaengine_tx_status(sdd->tx_dma.ch, sdd->tx_dma.cookie, &s);
804 					dmaengine_terminate_all(sdd->tx_dma.ch);
805 					dev_err(&spi->dev, "TX residue: %d\n", s.residue);
806 
807 				}
808 				if (xfer->rx_buf && (sdd->state & RXBUSY)) {
809 					dmaengine_pause(sdd->rx_dma.ch);
810 					dmaengine_tx_status(sdd->rx_dma.ch, sdd->rx_dma.cookie, &s);
811 					dmaengine_terminate_all(sdd->rx_dma.ch);
812 					dev_err(&spi->dev, "RX residue: %d\n", s.residue);
813 				}
814 			}
815 		} else {
816 			s3c64xx_flush_fifo(sdd);
817 		}
818 		if (target_len > 0) {
819 			target_len -= xfer->len;
820 
821 			if (xfer->tx_buf)
822 				xfer->tx_buf += xfer->len;
823 
824 			if (xfer->rx_buf)
825 				xfer->rx_buf += xfer->len;
826 
827 			if (target_len > fifo_len)
828 				xfer->len = fifo_len;
829 			else
830 				xfer->len = target_len;
831 		}
832 	} while (target_len > 0);
833 
834 	if (origin_len) {
835 		/* Restore original xfer buffers and length */
836 		xfer->tx_buf = tx_buf;
837 		xfer->rx_buf = rx_buf;
838 		xfer->len = origin_len;
839 	}
840 
841 	return status;
842 }
843 
844 static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
845 				struct spi_device *spi)
846 {
847 	struct s3c64xx_spi_csinfo *cs;
848 	struct device_node *slave_np, *data_np = NULL;
849 	u32 fb_delay = 0;
850 
851 	slave_np = spi->dev.of_node;
852 	if (!slave_np) {
853 		dev_err(&spi->dev, "device node not found\n");
854 		return ERR_PTR(-EINVAL);
855 	}
856 
857 	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
858 	if (!cs)
859 		return ERR_PTR(-ENOMEM);
860 
861 	data_np = of_get_child_by_name(slave_np, "controller-data");
862 	if (!data_np) {
863 		dev_info(&spi->dev, "feedback delay set to default (0)\n");
864 		return cs;
865 	}
866 
867 	of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
868 	cs->fb_delay = fb_delay;
869 	of_node_put(data_np);
870 	return cs;
871 }
872 
873 /*
874  * Here we only check the validity of requested configuration
875  * and save the configuration in a local data-structure.
876  * The controller is actually configured only just before we
877  * get a message to transfer.
878  */
879 static int s3c64xx_spi_setup(struct spi_device *spi)
880 {
881 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
882 	struct s3c64xx_spi_driver_data *sdd;
883 	int err;
884 	int div;
885 
886 	sdd = spi_master_get_devdata(spi->master);
887 	if (spi->dev.of_node) {
888 		cs = s3c64xx_get_slave_ctrldata(spi);
889 		spi->controller_data = cs;
890 	}
891 
892 	/* NULL is fine, we just avoid using the FB delay (=0) */
893 	if (IS_ERR(cs)) {
894 		dev_err(&spi->dev, "No CS for SPI(%d)\n", spi_get_chipselect(spi, 0));
895 		return -ENODEV;
896 	}
897 
898 	if (!spi_get_ctldata(spi))
899 		spi_set_ctldata(spi, cs);
900 
901 	pm_runtime_get_sync(&sdd->pdev->dev);
902 
903 	div = sdd->port_conf->clk_div;
904 
905 	/* Check if we can provide the requested rate */
906 	if (!sdd->port_conf->clk_from_cmu) {
907 		u32 psr, speed;
908 
909 		/* Max possible */
910 		speed = clk_get_rate(sdd->src_clk) / div / (0 + 1);
911 
912 		if (spi->max_speed_hz > speed)
913 			spi->max_speed_hz = speed;
914 
915 		psr = clk_get_rate(sdd->src_clk) / div / spi->max_speed_hz - 1;
916 		psr &= S3C64XX_SPI_PSR_MASK;
917 		if (psr == S3C64XX_SPI_PSR_MASK)
918 			psr--;
919 
920 		speed = clk_get_rate(sdd->src_clk) / div / (psr + 1);
921 		if (spi->max_speed_hz < speed) {
922 			if (psr+1 < S3C64XX_SPI_PSR_MASK) {
923 				psr++;
924 			} else {
925 				err = -EINVAL;
926 				goto setup_exit;
927 			}
928 		}
929 
930 		speed = clk_get_rate(sdd->src_clk) / div / (psr + 1);
931 		if (spi->max_speed_hz >= speed) {
932 			spi->max_speed_hz = speed;
933 		} else {
934 			dev_err(&spi->dev, "Can't set %dHz transfer speed\n",
935 				spi->max_speed_hz);
936 			err = -EINVAL;
937 			goto setup_exit;
938 		}
939 	}
940 
941 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
942 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
943 	s3c64xx_spi_set_cs(spi, false);
944 
945 	return 0;
946 
947 setup_exit:
948 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
949 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
950 	/* setup() returns with device de-selected */
951 	s3c64xx_spi_set_cs(spi, false);
952 
953 	spi_set_ctldata(spi, NULL);
954 
955 	/* This was dynamically allocated on the DT path */
956 	if (spi->dev.of_node)
957 		kfree(cs);
958 
959 	return err;
960 }
961 
962 static void s3c64xx_spi_cleanup(struct spi_device *spi)
963 {
964 	struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
965 
966 	/* This was dynamically allocated on the DT path */
967 	if (spi->dev.of_node)
968 		kfree(cs);
969 
970 	spi_set_ctldata(spi, NULL);
971 }
972 
973 static irqreturn_t s3c64xx_spi_irq(int irq, void *data)
974 {
975 	struct s3c64xx_spi_driver_data *sdd = data;
976 	struct spi_master *spi = sdd->master;
977 	unsigned int val, clr = 0;
978 
979 	val = readl(sdd->regs + S3C64XX_SPI_STATUS);
980 
981 	if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) {
982 		clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR;
983 		dev_err(&spi->dev, "RX overrun\n");
984 	}
985 	if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) {
986 		clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR;
987 		dev_err(&spi->dev, "RX underrun\n");
988 	}
989 	if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) {
990 		clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR;
991 		dev_err(&spi->dev, "TX overrun\n");
992 	}
993 	if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) {
994 		clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
995 		dev_err(&spi->dev, "TX underrun\n");
996 	}
997 
998 	/* Clear the pending irq by setting and then clearing it */
999 	writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR);
1000 	writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR);
1001 
1002 	return IRQ_HANDLED;
1003 }
1004 
1005 static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd)
1006 {
1007 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1008 	void __iomem *regs = sdd->regs;
1009 	unsigned int val;
1010 
1011 	sdd->cur_speed = 0;
1012 
1013 	if (sci->no_cs)
1014 		writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
1015 	else if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
1016 		writel(S3C64XX_SPI_CS_SIG_INACT, sdd->regs + S3C64XX_SPI_CS_REG);
1017 
1018 	/* Disable Interrupts - we use Polling if not DMA mode */
1019 	writel(0, regs + S3C64XX_SPI_INT_EN);
1020 
1021 	if (!sdd->port_conf->clk_from_cmu)
1022 		writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
1023 				regs + S3C64XX_SPI_CLK_CFG);
1024 	writel(0, regs + S3C64XX_SPI_MODE_CFG);
1025 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
1026 
1027 	/* Clear any irq pending bits, should set and clear the bits */
1028 	val = S3C64XX_SPI_PND_RX_OVERRUN_CLR |
1029 		S3C64XX_SPI_PND_RX_UNDERRUN_CLR |
1030 		S3C64XX_SPI_PND_TX_OVERRUN_CLR |
1031 		S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
1032 	writel(val, regs + S3C64XX_SPI_PENDING_CLR);
1033 	writel(0, regs + S3C64XX_SPI_PENDING_CLR);
1034 
1035 	writel(0, regs + S3C64XX_SPI_SWAP_CFG);
1036 
1037 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
1038 	val &= ~S3C64XX_SPI_MODE_4BURST;
1039 	val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
1040 	val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
1041 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
1042 
1043 	s3c64xx_flush_fifo(sdd);
1044 }
1045 
1046 #ifdef CONFIG_OF
1047 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1048 {
1049 	struct s3c64xx_spi_info *sci;
1050 	u32 temp;
1051 
1052 	sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
1053 	if (!sci)
1054 		return ERR_PTR(-ENOMEM);
1055 
1056 	if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
1057 		dev_warn(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
1058 		sci->src_clk_nr = 0;
1059 	} else {
1060 		sci->src_clk_nr = temp;
1061 	}
1062 
1063 	if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
1064 		dev_warn(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
1065 		sci->num_cs = 1;
1066 	} else {
1067 		sci->num_cs = temp;
1068 	}
1069 
1070 	sci->no_cs = of_property_read_bool(dev->of_node, "no-cs-readback");
1071 
1072 	return sci;
1073 }
1074 #else
1075 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1076 {
1077 	return dev_get_platdata(dev);
1078 }
1079 #endif
1080 
1081 static inline const struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
1082 						struct platform_device *pdev)
1083 {
1084 #ifdef CONFIG_OF
1085 	if (pdev->dev.of_node)
1086 		return of_device_get_match_data(&pdev->dev);
1087 #endif
1088 	return (const struct s3c64xx_spi_port_config *)platform_get_device_id(pdev)->driver_data;
1089 }
1090 
1091 static int s3c64xx_spi_probe(struct platform_device *pdev)
1092 {
1093 	struct resource	*mem_res;
1094 	struct s3c64xx_spi_driver_data *sdd;
1095 	struct s3c64xx_spi_info *sci = dev_get_platdata(&pdev->dev);
1096 	struct spi_master *master;
1097 	int ret, irq;
1098 	char clk_name[16];
1099 
1100 	if (!sci && pdev->dev.of_node) {
1101 		sci = s3c64xx_spi_parse_dt(&pdev->dev);
1102 		if (IS_ERR(sci))
1103 			return PTR_ERR(sci);
1104 	}
1105 
1106 	if (!sci) {
1107 		dev_err(&pdev->dev, "platform_data missing!\n");
1108 		return -ENODEV;
1109 	}
1110 
1111 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1112 	if (mem_res == NULL) {
1113 		dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
1114 		return -ENXIO;
1115 	}
1116 
1117 	irq = platform_get_irq(pdev, 0);
1118 	if (irq < 0) {
1119 		dev_warn(&pdev->dev, "Failed to get IRQ: %d\n", irq);
1120 		return irq;
1121 	}
1122 
1123 	master = spi_alloc_master(&pdev->dev,
1124 				sizeof(struct s3c64xx_spi_driver_data));
1125 	if (master == NULL) {
1126 		dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
1127 		return -ENOMEM;
1128 	}
1129 
1130 	platform_set_drvdata(pdev, master);
1131 
1132 	sdd = spi_master_get_devdata(master);
1133 	sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
1134 	sdd->master = master;
1135 	sdd->cntrlr_info = sci;
1136 	sdd->pdev = pdev;
1137 	sdd->sfr_start = mem_res->start;
1138 	if (pdev->dev.of_node) {
1139 		ret = of_alias_get_id(pdev->dev.of_node, "spi");
1140 		if (ret < 0) {
1141 			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
1142 				ret);
1143 			goto err_deref_master;
1144 		}
1145 		sdd->port_id = ret;
1146 	} else {
1147 		sdd->port_id = pdev->id;
1148 	}
1149 
1150 	sdd->cur_bpw = 8;
1151 
1152 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
1153 	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
1154 
1155 	master->dev.of_node = pdev->dev.of_node;
1156 	master->bus_num = sdd->port_id;
1157 	master->setup = s3c64xx_spi_setup;
1158 	master->cleanup = s3c64xx_spi_cleanup;
1159 	master->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
1160 	master->unprepare_transfer_hardware = s3c64xx_spi_unprepare_transfer;
1161 	master->prepare_message = s3c64xx_spi_prepare_message;
1162 	master->transfer_one = s3c64xx_spi_transfer_one;
1163 	master->max_transfer_size = s3c64xx_spi_max_transfer_size;
1164 	master->num_chipselect = sci->num_cs;
1165 	master->use_gpio_descriptors = true;
1166 	master->dma_alignment = 8;
1167 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
1168 					SPI_BPW_MASK(8);
1169 	/* the spi->mode bits understood by this driver: */
1170 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1171 	if (sdd->port_conf->has_loopback)
1172 		master->mode_bits |= SPI_LOOP;
1173 	master->auto_runtime_pm = true;
1174 	if (!is_polling(sdd))
1175 		master->can_dma = s3c64xx_spi_can_dma;
1176 
1177 	sdd->regs = devm_ioremap_resource(&pdev->dev, mem_res);
1178 	if (IS_ERR(sdd->regs)) {
1179 		ret = PTR_ERR(sdd->regs);
1180 		goto err_deref_master;
1181 	}
1182 
1183 	if (sci->cfg_gpio && sci->cfg_gpio()) {
1184 		dev_err(&pdev->dev, "Unable to config gpio\n");
1185 		ret = -EBUSY;
1186 		goto err_deref_master;
1187 	}
1188 
1189 	/* Setup clocks */
1190 	sdd->clk = devm_clk_get(&pdev->dev, "spi");
1191 	if (IS_ERR(sdd->clk)) {
1192 		dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
1193 		ret = PTR_ERR(sdd->clk);
1194 		goto err_deref_master;
1195 	}
1196 
1197 	ret = clk_prepare_enable(sdd->clk);
1198 	if (ret) {
1199 		dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
1200 		goto err_deref_master;
1201 	}
1202 
1203 	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
1204 	sdd->src_clk = devm_clk_get(&pdev->dev, clk_name);
1205 	if (IS_ERR(sdd->src_clk)) {
1206 		dev_err(&pdev->dev,
1207 			"Unable to acquire clock '%s'\n", clk_name);
1208 		ret = PTR_ERR(sdd->src_clk);
1209 		goto err_disable_clk;
1210 	}
1211 
1212 	ret = clk_prepare_enable(sdd->src_clk);
1213 	if (ret) {
1214 		dev_err(&pdev->dev, "Couldn't enable clock '%s'\n", clk_name);
1215 		goto err_disable_clk;
1216 	}
1217 
1218 	if (sdd->port_conf->clk_ioclk) {
1219 		sdd->ioclk = devm_clk_get(&pdev->dev, "spi_ioclk");
1220 		if (IS_ERR(sdd->ioclk)) {
1221 			dev_err(&pdev->dev, "Unable to acquire 'ioclk'\n");
1222 			ret = PTR_ERR(sdd->ioclk);
1223 			goto err_disable_src_clk;
1224 		}
1225 
1226 		ret = clk_prepare_enable(sdd->ioclk);
1227 		if (ret) {
1228 			dev_err(&pdev->dev, "Couldn't enable clock 'ioclk'\n");
1229 			goto err_disable_src_clk;
1230 		}
1231 	}
1232 
1233 	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1234 	pm_runtime_use_autosuspend(&pdev->dev);
1235 	pm_runtime_set_active(&pdev->dev);
1236 	pm_runtime_enable(&pdev->dev);
1237 	pm_runtime_get_sync(&pdev->dev);
1238 
1239 	/* Setup Deufult Mode */
1240 	s3c64xx_spi_hwinit(sdd);
1241 
1242 	spin_lock_init(&sdd->lock);
1243 	init_completion(&sdd->xfer_completion);
1244 
1245 	ret = devm_request_irq(&pdev->dev, irq, s3c64xx_spi_irq, 0,
1246 				"spi-s3c64xx", sdd);
1247 	if (ret != 0) {
1248 		dev_err(&pdev->dev, "Failed to request IRQ %d: %d\n",
1249 			irq, ret);
1250 		goto err_pm_put;
1251 	}
1252 
1253 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1254 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1255 	       sdd->regs + S3C64XX_SPI_INT_EN);
1256 
1257 	ret = devm_spi_register_master(&pdev->dev, master);
1258 	if (ret != 0) {
1259 		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
1260 		goto err_pm_put;
1261 	}
1262 
1263 	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",
1264 					sdd->port_id, master->num_chipselect);
1265 	dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\n",
1266 					mem_res, (FIFO_LVL_MASK(sdd) >> 1) + 1);
1267 
1268 	pm_runtime_mark_last_busy(&pdev->dev);
1269 	pm_runtime_put_autosuspend(&pdev->dev);
1270 
1271 	return 0;
1272 
1273 err_pm_put:
1274 	pm_runtime_put_noidle(&pdev->dev);
1275 	pm_runtime_disable(&pdev->dev);
1276 	pm_runtime_set_suspended(&pdev->dev);
1277 
1278 	clk_disable_unprepare(sdd->ioclk);
1279 err_disable_src_clk:
1280 	clk_disable_unprepare(sdd->src_clk);
1281 err_disable_clk:
1282 	clk_disable_unprepare(sdd->clk);
1283 err_deref_master:
1284 	spi_master_put(master);
1285 
1286 	return ret;
1287 }
1288 
1289 static void s3c64xx_spi_remove(struct platform_device *pdev)
1290 {
1291 	struct spi_master *master = platform_get_drvdata(pdev);
1292 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1293 
1294 	pm_runtime_get_sync(&pdev->dev);
1295 
1296 	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
1297 
1298 	if (!is_polling(sdd)) {
1299 		dma_release_channel(sdd->rx_dma.ch);
1300 		dma_release_channel(sdd->tx_dma.ch);
1301 	}
1302 
1303 	clk_disable_unprepare(sdd->ioclk);
1304 
1305 	clk_disable_unprepare(sdd->src_clk);
1306 
1307 	clk_disable_unprepare(sdd->clk);
1308 
1309 	pm_runtime_put_noidle(&pdev->dev);
1310 	pm_runtime_disable(&pdev->dev);
1311 	pm_runtime_set_suspended(&pdev->dev);
1312 }
1313 
1314 #ifdef CONFIG_PM_SLEEP
1315 static int s3c64xx_spi_suspend(struct device *dev)
1316 {
1317 	struct spi_master *master = dev_get_drvdata(dev);
1318 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1319 
1320 	int ret = spi_master_suspend(master);
1321 	if (ret)
1322 		return ret;
1323 
1324 	ret = pm_runtime_force_suspend(dev);
1325 	if (ret < 0)
1326 		return ret;
1327 
1328 	sdd->cur_speed = 0; /* Output Clock is stopped */
1329 
1330 	return 0;
1331 }
1332 
1333 static int s3c64xx_spi_resume(struct device *dev)
1334 {
1335 	struct spi_master *master = dev_get_drvdata(dev);
1336 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1337 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1338 	int ret;
1339 
1340 	if (sci->cfg_gpio)
1341 		sci->cfg_gpio();
1342 
1343 	ret = pm_runtime_force_resume(dev);
1344 	if (ret < 0)
1345 		return ret;
1346 
1347 	return spi_master_resume(master);
1348 }
1349 #endif /* CONFIG_PM_SLEEP */
1350 
1351 #ifdef CONFIG_PM
1352 static int s3c64xx_spi_runtime_suspend(struct device *dev)
1353 {
1354 	struct spi_master *master = dev_get_drvdata(dev);
1355 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1356 
1357 	clk_disable_unprepare(sdd->clk);
1358 	clk_disable_unprepare(sdd->src_clk);
1359 	clk_disable_unprepare(sdd->ioclk);
1360 
1361 	return 0;
1362 }
1363 
1364 static int s3c64xx_spi_runtime_resume(struct device *dev)
1365 {
1366 	struct spi_master *master = dev_get_drvdata(dev);
1367 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1368 	int ret;
1369 
1370 	if (sdd->port_conf->clk_ioclk) {
1371 		ret = clk_prepare_enable(sdd->ioclk);
1372 		if (ret != 0)
1373 			return ret;
1374 	}
1375 
1376 	ret = clk_prepare_enable(sdd->src_clk);
1377 	if (ret != 0)
1378 		goto err_disable_ioclk;
1379 
1380 	ret = clk_prepare_enable(sdd->clk);
1381 	if (ret != 0)
1382 		goto err_disable_src_clk;
1383 
1384 	s3c64xx_spi_hwinit(sdd);
1385 
1386 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1387 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1388 	       sdd->regs + S3C64XX_SPI_INT_EN);
1389 
1390 	return 0;
1391 
1392 err_disable_src_clk:
1393 	clk_disable_unprepare(sdd->src_clk);
1394 err_disable_ioclk:
1395 	clk_disable_unprepare(sdd->ioclk);
1396 
1397 	return ret;
1398 }
1399 #endif /* CONFIG_PM */
1400 
1401 static const struct dev_pm_ops s3c64xx_spi_pm = {
1402 	SET_SYSTEM_SLEEP_PM_OPS(s3c64xx_spi_suspend, s3c64xx_spi_resume)
1403 	SET_RUNTIME_PM_OPS(s3c64xx_spi_runtime_suspend,
1404 			   s3c64xx_spi_runtime_resume, NULL)
1405 };
1406 
1407 static const struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
1408 	.fifo_lvl_mask	= { 0x7f },
1409 	.rx_lvl_offset	= 13,
1410 	.tx_st_done	= 21,
1411 	.clk_div	= 2,
1412 	.high_speed	= true,
1413 };
1414 
1415 static const struct s3c64xx_spi_port_config s3c6410_spi_port_config = {
1416 	.fifo_lvl_mask	= { 0x7f, 0x7F },
1417 	.rx_lvl_offset	= 13,
1418 	.tx_st_done	= 21,
1419 	.clk_div	= 2,
1420 };
1421 
1422 static const struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
1423 	.fifo_lvl_mask	= { 0x1ff, 0x7F },
1424 	.rx_lvl_offset	= 15,
1425 	.tx_st_done	= 25,
1426 	.clk_div	= 2,
1427 	.high_speed	= true,
1428 };
1429 
1430 static const struct s3c64xx_spi_port_config exynos4_spi_port_config = {
1431 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F },
1432 	.rx_lvl_offset	= 15,
1433 	.tx_st_done	= 25,
1434 	.clk_div	= 2,
1435 	.high_speed	= true,
1436 	.clk_from_cmu	= true,
1437 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1438 };
1439 
1440 static const struct s3c64xx_spi_port_config exynos7_spi_port_config = {
1441 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},
1442 	.rx_lvl_offset	= 15,
1443 	.tx_st_done	= 25,
1444 	.clk_div	= 2,
1445 	.high_speed	= true,
1446 	.clk_from_cmu	= true,
1447 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1448 };
1449 
1450 static const struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
1451 	.fifo_lvl_mask	= { 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff},
1452 	.rx_lvl_offset	= 15,
1453 	.tx_st_done	= 25,
1454 	.clk_div	= 2,
1455 	.high_speed	= true,
1456 	.clk_from_cmu	= true,
1457 	.clk_ioclk	= true,
1458 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1459 };
1460 
1461 static const struct s3c64xx_spi_port_config exynosautov9_spi_port_config = {
1462 	.fifo_lvl_mask	= { 0x1ff, 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff, 0x7f,
1463 			    0x7f, 0x7f, 0x7f, 0x7f},
1464 	.rx_lvl_offset	= 15,
1465 	.tx_st_done	= 25,
1466 	.clk_div	= 4,
1467 	.high_speed	= true,
1468 	.clk_from_cmu	= true,
1469 	.clk_ioclk	= true,
1470 	.has_loopback	= true,
1471 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1472 };
1473 
1474 static const struct s3c64xx_spi_port_config fsd_spi_port_config = {
1475 	.fifo_lvl_mask	= { 0x7f, 0x7f, 0x7f, 0x7f, 0x7f},
1476 	.rx_lvl_offset	= 15,
1477 	.tx_st_done	= 25,
1478 	.clk_div	= 2,
1479 	.high_speed	= true,
1480 	.clk_from_cmu	= true,
1481 	.clk_ioclk	= false,
1482 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1483 };
1484 
1485 static const struct platform_device_id s3c64xx_spi_driver_ids[] = {
1486 	{
1487 		.name		= "s3c2443-spi",
1488 		.driver_data	= (kernel_ulong_t)&s3c2443_spi_port_config,
1489 	}, {
1490 		.name		= "s3c6410-spi",
1491 		.driver_data	= (kernel_ulong_t)&s3c6410_spi_port_config,
1492 	},
1493 	{ },
1494 };
1495 
1496 static const struct of_device_id s3c64xx_spi_dt_match[] = {
1497 	{ .compatible = "samsung,s3c2443-spi",
1498 			.data = (void *)&s3c2443_spi_port_config,
1499 	},
1500 	{ .compatible = "samsung,s3c6410-spi",
1501 			.data = (void *)&s3c6410_spi_port_config,
1502 	},
1503 	{ .compatible = "samsung,s5pv210-spi",
1504 			.data = (void *)&s5pv210_spi_port_config,
1505 	},
1506 	{ .compatible = "samsung,exynos4210-spi",
1507 			.data = (void *)&exynos4_spi_port_config,
1508 	},
1509 	{ .compatible = "samsung,exynos7-spi",
1510 			.data = (void *)&exynos7_spi_port_config,
1511 	},
1512 	{ .compatible = "samsung,exynos5433-spi",
1513 			.data = (void *)&exynos5433_spi_port_config,
1514 	},
1515 	{ .compatible = "samsung,exynosautov9-spi",
1516 			.data = (void *)&exynosautov9_spi_port_config,
1517 	},
1518 	{ .compatible = "tesla,fsd-spi",
1519 			.data = (void *)&fsd_spi_port_config,
1520 	},
1521 	{ },
1522 };
1523 MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
1524 
1525 static struct platform_driver s3c64xx_spi_driver = {
1526 	.driver = {
1527 		.name	= "s3c64xx-spi",
1528 		.pm = &s3c64xx_spi_pm,
1529 		.of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
1530 	},
1531 	.probe = s3c64xx_spi_probe,
1532 	.remove_new = s3c64xx_spi_remove,
1533 	.id_table = s3c64xx_spi_driver_ids,
1534 };
1535 MODULE_ALIAS("platform:s3c64xx-spi");
1536 
1537 module_platform_driver(s3c64xx_spi_driver);
1538 
1539 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1540 MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1541 MODULE_LICENSE("GPL");
1542