xref: /openbmc/linux/drivers/spi/spi-s3c64xx.c (revision bb26cfd9)
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 
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 	dma_cookie_t cookie;
126 	enum dma_transfer_direction direction;
127 };
128 
129 /**
130  * struct s3c64xx_spi_port_config - SPI Controller hardware info
131  * @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
132  * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
133  * @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
134  * @clk_div: Internal clock divider
135  * @quirks: Bitmask of known quirks
136  * @high_speed: True, if the controller supports HIGH_SPEED_EN bit.
137  * @clk_from_cmu: True, if the controller does not include a clock mux and
138  *	prescaler unit.
139  * @clk_ioclk: True if clock is present on this device
140  * @has_loopback: True if loopback mode can be supported
141  *
142  * The Samsung s3c64xx SPI controller are used on various Samsung SoC's but
143  * differ in some aspects such as the size of the fifo and spi bus clock
144  * setup. Such differences are specified to the driver using this structure
145  * which is provided as driver data to the driver.
146  */
147 struct s3c64xx_spi_port_config {
148 	int	fifo_lvl_mask[MAX_SPI_PORTS];
149 	int	rx_lvl_offset;
150 	int	tx_st_done;
151 	int	quirks;
152 	int	clk_div;
153 	bool	high_speed;
154 	bool	clk_from_cmu;
155 	bool	clk_ioclk;
156 	bool	has_loopback;
157 };
158 
159 /**
160  * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
161  * @clk: Pointer to the spi clock.
162  * @src_clk: Pointer to the clock used to generate SPI signals.
163  * @ioclk: Pointer to the i/o clock between master and slave
164  * @pdev: Pointer to device's platform device data
165  * @master: Pointer to the SPI Protocol master.
166  * @cntrlr_info: Platform specific data for the controller this driver manages.
167  * @lock: Controller specific lock.
168  * @state: Set of FLAGS to indicate status.
169  * @sfr_start: BUS address of SPI controller regs.
170  * @regs: Pointer to ioremap'ed controller registers.
171  * @xfer_completion: To indicate completion of xfer task.
172  * @cur_mode: Stores the active configuration of the controller.
173  * @cur_bpw: Stores the active bits per word settings.
174  * @cur_speed: Current clock speed
175  * @rx_dma: Local receive DMA data (e.g. chan and direction)
176  * @tx_dma: Local transmit DMA data (e.g. chan and direction)
177  * @port_conf: Local SPI port configuartion data
178  * @port_id: Port identification number
179  */
180 struct s3c64xx_spi_driver_data {
181 	void __iomem                    *regs;
182 	struct clk                      *clk;
183 	struct clk                      *src_clk;
184 	struct clk                      *ioclk;
185 	struct platform_device          *pdev;
186 	struct spi_master               *master;
187 	struct s3c64xx_spi_info         *cntrlr_info;
188 	spinlock_t                      lock;
189 	unsigned long                   sfr_start;
190 	struct completion               xfer_completion;
191 	unsigned                        state;
192 	unsigned                        cur_mode, cur_bpw;
193 	unsigned                        cur_speed;
194 	struct s3c64xx_spi_dma_data	rx_dma;
195 	struct s3c64xx_spi_dma_data	tx_dma;
196 	const struct s3c64xx_spi_port_config	*port_conf;
197 	unsigned int			port_id;
198 };
199 
200 static void s3c64xx_flush_fifo(struct s3c64xx_spi_driver_data *sdd)
201 {
202 	void __iomem *regs = sdd->regs;
203 	unsigned long loops;
204 	u32 val;
205 
206 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
207 
208 	val = readl(regs + S3C64XX_SPI_CH_CFG);
209 	val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON);
210 	writel(val, regs + S3C64XX_SPI_CH_CFG);
211 
212 	val = readl(regs + S3C64XX_SPI_CH_CFG);
213 	val |= S3C64XX_SPI_CH_SW_RST;
214 	val &= ~S3C64XX_SPI_CH_HS_EN;
215 	writel(val, regs + S3C64XX_SPI_CH_CFG);
216 
217 	/* Flush TxFIFO*/
218 	loops = msecs_to_loops(1);
219 	do {
220 		val = readl(regs + S3C64XX_SPI_STATUS);
221 	} while (TX_FIFO_LVL(val, sdd) && loops--);
222 
223 	if (loops == 0)
224 		dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n");
225 
226 	/* Flush RxFIFO*/
227 	loops = msecs_to_loops(1);
228 	do {
229 		val = readl(regs + S3C64XX_SPI_STATUS);
230 		if (RX_FIFO_LVL(val, sdd))
231 			readl(regs + S3C64XX_SPI_RX_DATA);
232 		else
233 			break;
234 	} while (loops--);
235 
236 	if (loops == 0)
237 		dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n");
238 
239 	val = readl(regs + S3C64XX_SPI_CH_CFG);
240 	val &= ~S3C64XX_SPI_CH_SW_RST;
241 	writel(val, regs + S3C64XX_SPI_CH_CFG);
242 
243 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
244 	val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
245 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
246 }
247 
248 static void s3c64xx_spi_dmacb(void *data)
249 {
250 	struct s3c64xx_spi_driver_data *sdd;
251 	struct s3c64xx_spi_dma_data *dma = data;
252 	unsigned long flags;
253 
254 	if (dma->direction == DMA_DEV_TO_MEM)
255 		sdd = container_of(data,
256 			struct s3c64xx_spi_driver_data, rx_dma);
257 	else
258 		sdd = container_of(data,
259 			struct s3c64xx_spi_driver_data, tx_dma);
260 
261 	spin_lock_irqsave(&sdd->lock, flags);
262 
263 	if (dma->direction == DMA_DEV_TO_MEM) {
264 		sdd->state &= ~RXBUSY;
265 		if (!(sdd->state & TXBUSY))
266 			complete(&sdd->xfer_completion);
267 	} else {
268 		sdd->state &= ~TXBUSY;
269 		if (!(sdd->state & RXBUSY))
270 			complete(&sdd->xfer_completion);
271 	}
272 
273 	spin_unlock_irqrestore(&sdd->lock, flags);
274 }
275 
276 static int prepare_dma(struct s3c64xx_spi_dma_data *dma,
277 			struct sg_table *sgt)
278 {
279 	struct s3c64xx_spi_driver_data *sdd;
280 	struct dma_slave_config config;
281 	struct dma_async_tx_descriptor *desc;
282 	int ret;
283 
284 	memset(&config, 0, sizeof(config));
285 
286 	if (dma->direction == DMA_DEV_TO_MEM) {
287 		sdd = container_of((void *)dma,
288 			struct s3c64xx_spi_driver_data, rx_dma);
289 		config.direction = dma->direction;
290 		config.src_addr = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
291 		config.src_addr_width = sdd->cur_bpw / 8;
292 		config.src_maxburst = 1;
293 		dmaengine_slave_config(dma->ch, &config);
294 	} else {
295 		sdd = container_of((void *)dma,
296 			struct s3c64xx_spi_driver_data, tx_dma);
297 		config.direction = dma->direction;
298 		config.dst_addr = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
299 		config.dst_addr_width = sdd->cur_bpw / 8;
300 		config.dst_maxburst = 1;
301 		dmaengine_slave_config(dma->ch, &config);
302 	}
303 
304 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
305 				       dma->direction, DMA_PREP_INTERRUPT);
306 	if (!desc) {
307 		dev_err(&sdd->pdev->dev, "unable to prepare %s scatterlist",
308 			dma->direction == DMA_DEV_TO_MEM ? "rx" : "tx");
309 		return -ENOMEM;
310 	}
311 
312 	desc->callback = s3c64xx_spi_dmacb;
313 	desc->callback_param = dma;
314 
315 	dma->cookie = dmaengine_submit(desc);
316 	ret = dma_submit_error(dma->cookie);
317 	if (ret) {
318 		dev_err(&sdd->pdev->dev, "DMA submission failed");
319 		return -EIO;
320 	}
321 
322 	dma_async_issue_pending(dma->ch);
323 	return 0;
324 }
325 
326 static void s3c64xx_spi_set_cs(struct spi_device *spi, bool enable)
327 {
328 	struct s3c64xx_spi_driver_data *sdd =
329 					spi_master_get_devdata(spi->master);
330 
331 	if (sdd->cntrlr_info->no_cs)
332 		return;
333 
334 	if (enable) {
335 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO)) {
336 			writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
337 		} else {
338 			u32 ssel = readl(sdd->regs + S3C64XX_SPI_CS_REG);
339 
340 			ssel |= (S3C64XX_SPI_CS_AUTO |
341 						S3C64XX_SPI_CS_NSC_CNT_2);
342 			writel(ssel, sdd->regs + S3C64XX_SPI_CS_REG);
343 		}
344 	} else {
345 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
346 			writel(S3C64XX_SPI_CS_SIG_INACT,
347 			       sdd->regs + S3C64XX_SPI_CS_REG);
348 	}
349 }
350 
351 static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
352 {
353 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
354 
355 	if (is_polling(sdd))
356 		return 0;
357 
358 	/* Requests DMA channels */
359 	sdd->rx_dma.ch = dma_request_chan(&sdd->pdev->dev, "rx");
360 	if (IS_ERR(sdd->rx_dma.ch)) {
361 		dev_err(&sdd->pdev->dev, "Failed to get RX DMA channel\n");
362 		sdd->rx_dma.ch = NULL;
363 		return 0;
364 	}
365 
366 	sdd->tx_dma.ch = dma_request_chan(&sdd->pdev->dev, "tx");
367 	if (IS_ERR(sdd->tx_dma.ch)) {
368 		dev_err(&sdd->pdev->dev, "Failed to get TX DMA channel\n");
369 		dma_release_channel(sdd->rx_dma.ch);
370 		sdd->tx_dma.ch = NULL;
371 		sdd->rx_dma.ch = NULL;
372 		return 0;
373 	}
374 
375 	spi->dma_rx = sdd->rx_dma.ch;
376 	spi->dma_tx = sdd->tx_dma.ch;
377 
378 	return 0;
379 }
380 
381 static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
382 {
383 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
384 
385 	if (is_polling(sdd))
386 		return 0;
387 
388 	/* Releases DMA channels if they are allocated */
389 	if (sdd->rx_dma.ch && sdd->tx_dma.ch) {
390 		dma_release_channel(sdd->rx_dma.ch);
391 		dma_release_channel(sdd->tx_dma.ch);
392 		sdd->rx_dma.ch = 0;
393 		sdd->tx_dma.ch = 0;
394 	}
395 
396 	return 0;
397 }
398 
399 static bool s3c64xx_spi_can_dma(struct spi_master *master,
400 				struct spi_device *spi,
401 				struct spi_transfer *xfer)
402 {
403 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
404 
405 	if (sdd->rx_dma.ch && sdd->tx_dma.ch) {
406 		return xfer->len > (FIFO_LVL_MASK(sdd) >> 1) + 1;
407 	} else {
408 		return false;
409 	}
410 
411 }
412 
413 static int s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
414 				    struct spi_transfer *xfer, int dma_mode)
415 {
416 	void __iomem *regs = sdd->regs;
417 	u32 modecfg, chcfg;
418 	int ret = 0;
419 
420 	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
421 	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
422 
423 	chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
424 	chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
425 
426 	if (dma_mode) {
427 		chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
428 	} else {
429 		/* Always shift in data in FIFO, even if xfer is Tx only,
430 		 * this helps setting PCKT_CNT value for generating clocks
431 		 * as exactly needed.
432 		 */
433 		chcfg |= S3C64XX_SPI_CH_RXCH_ON;
434 		writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
435 					| S3C64XX_SPI_PACKET_CNT_EN,
436 					regs + S3C64XX_SPI_PACKET_CNT);
437 	}
438 
439 	if (xfer->tx_buf != NULL) {
440 		sdd->state |= TXBUSY;
441 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
442 		if (dma_mode) {
443 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
444 			ret = prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
445 		} else {
446 			switch (sdd->cur_bpw) {
447 			case 32:
448 				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
449 					xfer->tx_buf, xfer->len / 4);
450 				break;
451 			case 16:
452 				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
453 					xfer->tx_buf, xfer->len / 2);
454 				break;
455 			default:
456 				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
457 					xfer->tx_buf, xfer->len);
458 				break;
459 			}
460 		}
461 	}
462 
463 	if (xfer->rx_buf != NULL) {
464 		sdd->state |= RXBUSY;
465 
466 		if (sdd->port_conf->high_speed && sdd->cur_speed >= 30000000UL
467 					&& !(sdd->cur_mode & SPI_CPHA))
468 			chcfg |= S3C64XX_SPI_CH_HS_EN;
469 
470 		if (dma_mode) {
471 			modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
472 			chcfg |= S3C64XX_SPI_CH_RXCH_ON;
473 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
474 					| S3C64XX_SPI_PACKET_CNT_EN,
475 					regs + S3C64XX_SPI_PACKET_CNT);
476 			ret = prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
477 		}
478 	}
479 
480 	if (ret)
481 		return ret;
482 
483 	writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
484 	writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
485 
486 	return 0;
487 }
488 
489 static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
490 					int timeout_ms)
491 {
492 	void __iomem *regs = sdd->regs;
493 	unsigned long val = 1;
494 	u32 status;
495 
496 	/* max fifo depth available */
497 	u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
498 
499 	if (timeout_ms)
500 		val = msecs_to_loops(timeout_ms);
501 
502 	do {
503 		status = readl(regs + S3C64XX_SPI_STATUS);
504 	} while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
505 
506 	/* return the actual received data length */
507 	return RX_FIFO_LVL(status, sdd);
508 }
509 
510 static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
511 				struct spi_transfer *xfer)
512 {
513 	void __iomem *regs = sdd->regs;
514 	unsigned long val;
515 	u32 status;
516 	int ms;
517 
518 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
519 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
520 	ms += 30;               /* some tolerance */
521 	ms = max(ms, 100);      /* minimum timeout */
522 
523 	val = msecs_to_jiffies(ms) + 10;
524 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
525 
526 	/*
527 	 * If the previous xfer was completed within timeout, then
528 	 * proceed further else return -EIO.
529 	 * DmaTx returns after simply writing data in the FIFO,
530 	 * w/o waiting for real transmission on the bus to finish.
531 	 * DmaRx returns only after Dma read data from FIFO which
532 	 * needs bus transmission to finish, so we don't worry if
533 	 * Xfer involved Rx(with or without Tx).
534 	 */
535 	if (val && !xfer->rx_buf) {
536 		val = msecs_to_loops(10);
537 		status = readl(regs + S3C64XX_SPI_STATUS);
538 		while ((TX_FIFO_LVL(status, sdd)
539 			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
540 		       && --val) {
541 			cpu_relax();
542 			status = readl(regs + S3C64XX_SPI_STATUS);
543 		}
544 
545 	}
546 
547 	/* If timed out while checking rx/tx status return error */
548 	if (!val)
549 		return -EIO;
550 
551 	return 0;
552 }
553 
554 static int s3c64xx_wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
555 				struct spi_transfer *xfer)
556 {
557 	void __iomem *regs = sdd->regs;
558 	unsigned long val;
559 	u32 status;
560 	int loops;
561 	u32 cpy_len;
562 	u8 *buf;
563 	int ms;
564 
565 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
566 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
567 	ms += 10; /* some tolerance */
568 
569 	val = msecs_to_loops(ms);
570 	do {
571 		status = readl(regs + S3C64XX_SPI_STATUS);
572 	} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
573 
574 	if (!val)
575 		return -EIO;
576 
577 	/* If it was only Tx */
578 	if (!xfer->rx_buf) {
579 		sdd->state &= ~TXBUSY;
580 		return 0;
581 	}
582 
583 	/*
584 	 * If the receive length is bigger than the controller fifo
585 	 * size, calculate the loops and read the fifo as many times.
586 	 * loops = length / max fifo size (calculated by using the
587 	 * fifo mask).
588 	 * For any size less than the fifo size the below code is
589 	 * executed atleast once.
590 	 */
591 	loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
592 	buf = xfer->rx_buf;
593 	do {
594 		/* wait for data to be received in the fifo */
595 		cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
596 						       (loops ? ms : 0));
597 
598 		switch (sdd->cur_bpw) {
599 		case 32:
600 			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
601 				     buf, cpy_len / 4);
602 			break;
603 		case 16:
604 			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
605 				     buf, cpy_len / 2);
606 			break;
607 		default:
608 			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
609 				    buf, cpy_len);
610 			break;
611 		}
612 
613 		buf = buf + cpy_len;
614 	} while (loops--);
615 	sdd->state &= ~RXBUSY;
616 
617 	return 0;
618 }
619 
620 static int s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
621 {
622 	void __iomem *regs = sdd->regs;
623 	int ret;
624 	u32 val;
625 	int div = sdd->port_conf->clk_div;
626 
627 	/* Disable Clock */
628 	if (!sdd->port_conf->clk_from_cmu) {
629 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
630 		val &= ~S3C64XX_SPI_ENCLK_ENABLE;
631 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
632 	}
633 
634 	/* Set Polarity and Phase */
635 	val = readl(regs + S3C64XX_SPI_CH_CFG);
636 	val &= ~(S3C64XX_SPI_CH_SLAVE |
637 			S3C64XX_SPI_CPOL_L |
638 			S3C64XX_SPI_CPHA_B);
639 
640 	if (sdd->cur_mode & SPI_CPOL)
641 		val |= S3C64XX_SPI_CPOL_L;
642 
643 	if (sdd->cur_mode & SPI_CPHA)
644 		val |= S3C64XX_SPI_CPHA_B;
645 
646 	writel(val, regs + S3C64XX_SPI_CH_CFG);
647 
648 	/* Set Channel & DMA Mode */
649 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
650 	val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
651 			| S3C64XX_SPI_MODE_CH_TSZ_MASK);
652 
653 	switch (sdd->cur_bpw) {
654 	case 32:
655 		val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
656 		val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;
657 		break;
658 	case 16:
659 		val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
660 		val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;
661 		break;
662 	default:
663 		val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
664 		val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;
665 		break;
666 	}
667 
668 	if ((sdd->cur_mode & SPI_LOOP) && sdd->port_conf->has_loopback)
669 		val |= S3C64XX_SPI_MODE_SELF_LOOPBACK;
670 
671 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
672 
673 	if (sdd->port_conf->clk_from_cmu) {
674 		ret = clk_set_rate(sdd->src_clk, sdd->cur_speed * div);
675 		if (ret)
676 			return ret;
677 		sdd->cur_speed = clk_get_rate(sdd->src_clk) / div;
678 	} else {
679 		/* Configure Clock */
680 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
681 		val &= ~S3C64XX_SPI_PSR_MASK;
682 		val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / div - 1)
683 				& S3C64XX_SPI_PSR_MASK);
684 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
685 
686 		/* Enable Clock */
687 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
688 		val |= S3C64XX_SPI_ENCLK_ENABLE;
689 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
690 	}
691 
692 	return 0;
693 }
694 
695 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
696 
697 static int s3c64xx_spi_prepare_message(struct spi_master *master,
698 				       struct spi_message *msg)
699 {
700 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
701 	struct spi_device *spi = msg->spi;
702 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
703 
704 	/* Configure feedback delay */
705 	if (!cs)
706 		/* No delay if not defined */
707 		writel(0, sdd->regs + S3C64XX_SPI_FB_CLK);
708 	else
709 		writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
710 
711 	return 0;
712 }
713 
714 static int s3c64xx_spi_transfer_one(struct spi_master *master,
715 				    struct spi_device *spi,
716 				    struct spi_transfer *xfer)
717 {
718 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
719 	const unsigned int fifo_len = (FIFO_LVL_MASK(sdd) >> 1) + 1;
720 	const void *tx_buf = NULL;
721 	void *rx_buf = NULL;
722 	int target_len = 0, origin_len = 0;
723 	int use_dma = 0;
724 	int status;
725 	u32 speed;
726 	u8 bpw;
727 	unsigned long flags;
728 
729 	reinit_completion(&sdd->xfer_completion);
730 
731 	/* Only BPW and Speed may change across transfers */
732 	bpw = xfer->bits_per_word;
733 	speed = xfer->speed_hz;
734 
735 	if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
736 		sdd->cur_bpw = bpw;
737 		sdd->cur_speed = speed;
738 		sdd->cur_mode = spi->mode;
739 		status = s3c64xx_spi_config(sdd);
740 		if (status)
741 			return status;
742 	}
743 
744 	if (!is_polling(sdd) && (xfer->len > fifo_len) &&
745 	    sdd->rx_dma.ch && sdd->tx_dma.ch) {
746 		use_dma = 1;
747 
748 	} else if (xfer->len > fifo_len) {
749 		tx_buf = xfer->tx_buf;
750 		rx_buf = xfer->rx_buf;
751 		origin_len = xfer->len;
752 
753 		target_len = xfer->len;
754 		if (xfer->len > fifo_len)
755 			xfer->len = fifo_len;
756 	}
757 
758 	do {
759 		spin_lock_irqsave(&sdd->lock, flags);
760 
761 		/* Pending only which is to be done */
762 		sdd->state &= ~RXBUSY;
763 		sdd->state &= ~TXBUSY;
764 
765 		/* Start the signals */
766 		s3c64xx_spi_set_cs(spi, true);
767 
768 		status = s3c64xx_enable_datapath(sdd, xfer, use_dma);
769 
770 		spin_unlock_irqrestore(&sdd->lock, flags);
771 
772 		if (status) {
773 			dev_err(&spi->dev, "failed to enable data path for transfer: %d\n", status);
774 			break;
775 		}
776 
777 		if (use_dma)
778 			status = s3c64xx_wait_for_dma(sdd, xfer);
779 		else
780 			status = s3c64xx_wait_for_pio(sdd, xfer);
781 
782 		if (status) {
783 			dev_err(&spi->dev,
784 				"I/O Error: rx-%d tx-%d rx-%c tx-%c len-%d dma-%d res-(%d)\n",
785 				xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
786 				(sdd->state & RXBUSY) ? 'f' : 'p',
787 				(sdd->state & TXBUSY) ? 'f' : 'p',
788 				xfer->len, use_dma ? 1 : 0, status);
789 
790 			if (use_dma) {
791 				struct dma_tx_state s;
792 
793 				if (xfer->tx_buf && (sdd->state & TXBUSY)) {
794 					dmaengine_pause(sdd->tx_dma.ch);
795 					dmaengine_tx_status(sdd->tx_dma.ch, sdd->tx_dma.cookie, &s);
796 					dmaengine_terminate_all(sdd->tx_dma.ch);
797 					dev_err(&spi->dev, "TX residue: %d\n", s.residue);
798 
799 				}
800 				if (xfer->rx_buf && (sdd->state & RXBUSY)) {
801 					dmaengine_pause(sdd->rx_dma.ch);
802 					dmaengine_tx_status(sdd->rx_dma.ch, sdd->rx_dma.cookie, &s);
803 					dmaengine_terminate_all(sdd->rx_dma.ch);
804 					dev_err(&spi->dev, "RX residue: %d\n", s.residue);
805 				}
806 			}
807 		} else {
808 			s3c64xx_flush_fifo(sdd);
809 		}
810 		if (target_len > 0) {
811 			target_len -= xfer->len;
812 
813 			if (xfer->tx_buf)
814 				xfer->tx_buf += xfer->len;
815 
816 			if (xfer->rx_buf)
817 				xfer->rx_buf += xfer->len;
818 
819 			if (target_len > fifo_len)
820 				xfer->len = fifo_len;
821 			else
822 				xfer->len = target_len;
823 		}
824 	} while (target_len > 0);
825 
826 	if (origin_len) {
827 		/* Restore original xfer buffers and length */
828 		xfer->tx_buf = tx_buf;
829 		xfer->rx_buf = rx_buf;
830 		xfer->len = origin_len;
831 	}
832 
833 	return status;
834 }
835 
836 static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
837 				struct spi_device *spi)
838 {
839 	struct s3c64xx_spi_csinfo *cs;
840 	struct device_node *slave_np, *data_np = NULL;
841 	u32 fb_delay = 0;
842 
843 	slave_np = spi->dev.of_node;
844 	if (!slave_np) {
845 		dev_err(&spi->dev, "device node not found\n");
846 		return ERR_PTR(-EINVAL);
847 	}
848 
849 	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
850 	if (!cs)
851 		return ERR_PTR(-ENOMEM);
852 
853 	data_np = of_get_child_by_name(slave_np, "controller-data");
854 	if (!data_np) {
855 		dev_info(&spi->dev, "feedback delay set to default (0)\n");
856 		return cs;
857 	}
858 
859 	of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
860 	cs->fb_delay = fb_delay;
861 	of_node_put(data_np);
862 	return cs;
863 }
864 
865 /*
866  * Here we only check the validity of requested configuration
867  * and save the configuration in a local data-structure.
868  * The controller is actually configured only just before we
869  * get a message to transfer.
870  */
871 static int s3c64xx_spi_setup(struct spi_device *spi)
872 {
873 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
874 	struct s3c64xx_spi_driver_data *sdd;
875 	int err;
876 	int div;
877 
878 	sdd = spi_master_get_devdata(spi->master);
879 	if (spi->dev.of_node) {
880 		cs = s3c64xx_get_slave_ctrldata(spi);
881 		spi->controller_data = cs;
882 	}
883 
884 	/* NULL is fine, we just avoid using the FB delay (=0) */
885 	if (IS_ERR(cs)) {
886 		dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
887 		return -ENODEV;
888 	}
889 
890 	if (!spi_get_ctldata(spi))
891 		spi_set_ctldata(spi, cs);
892 
893 	pm_runtime_get_sync(&sdd->pdev->dev);
894 
895 	div = sdd->port_conf->clk_div;
896 
897 	/* Check if we can provide the requested rate */
898 	if (!sdd->port_conf->clk_from_cmu) {
899 		u32 psr, speed;
900 
901 		/* Max possible */
902 		speed = clk_get_rate(sdd->src_clk) / div / (0 + 1);
903 
904 		if (spi->max_speed_hz > speed)
905 			spi->max_speed_hz = speed;
906 
907 		psr = clk_get_rate(sdd->src_clk) / div / spi->max_speed_hz - 1;
908 		psr &= S3C64XX_SPI_PSR_MASK;
909 		if (psr == S3C64XX_SPI_PSR_MASK)
910 			psr--;
911 
912 		speed = clk_get_rate(sdd->src_clk) / div / (psr + 1);
913 		if (spi->max_speed_hz < speed) {
914 			if (psr+1 < S3C64XX_SPI_PSR_MASK) {
915 				psr++;
916 			} else {
917 				err = -EINVAL;
918 				goto setup_exit;
919 			}
920 		}
921 
922 		speed = clk_get_rate(sdd->src_clk) / div / (psr + 1);
923 		if (spi->max_speed_hz >= speed) {
924 			spi->max_speed_hz = speed;
925 		} else {
926 			dev_err(&spi->dev, "Can't set %dHz transfer speed\n",
927 				spi->max_speed_hz);
928 			err = -EINVAL;
929 			goto setup_exit;
930 		}
931 	}
932 
933 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
934 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
935 	s3c64xx_spi_set_cs(spi, false);
936 
937 	return 0;
938 
939 setup_exit:
940 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
941 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
942 	/* setup() returns with device de-selected */
943 	s3c64xx_spi_set_cs(spi, false);
944 
945 	spi_set_ctldata(spi, NULL);
946 
947 	/* This was dynamically allocated on the DT path */
948 	if (spi->dev.of_node)
949 		kfree(cs);
950 
951 	return err;
952 }
953 
954 static void s3c64xx_spi_cleanup(struct spi_device *spi)
955 {
956 	struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
957 
958 	/* This was dynamically allocated on the DT path */
959 	if (spi->dev.of_node)
960 		kfree(cs);
961 
962 	spi_set_ctldata(spi, NULL);
963 }
964 
965 static irqreturn_t s3c64xx_spi_irq(int irq, void *data)
966 {
967 	struct s3c64xx_spi_driver_data *sdd = data;
968 	struct spi_master *spi = sdd->master;
969 	unsigned int val, clr = 0;
970 
971 	val = readl(sdd->regs + S3C64XX_SPI_STATUS);
972 
973 	if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) {
974 		clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR;
975 		dev_err(&spi->dev, "RX overrun\n");
976 	}
977 	if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) {
978 		clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR;
979 		dev_err(&spi->dev, "RX underrun\n");
980 	}
981 	if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) {
982 		clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR;
983 		dev_err(&spi->dev, "TX overrun\n");
984 	}
985 	if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) {
986 		clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
987 		dev_err(&spi->dev, "TX underrun\n");
988 	}
989 
990 	/* Clear the pending irq by setting and then clearing it */
991 	writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR);
992 	writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR);
993 
994 	return IRQ_HANDLED;
995 }
996 
997 static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd)
998 {
999 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1000 	void __iomem *regs = sdd->regs;
1001 	unsigned int val;
1002 
1003 	sdd->cur_speed = 0;
1004 
1005 	if (sci->no_cs)
1006 		writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
1007 	else if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
1008 		writel(S3C64XX_SPI_CS_SIG_INACT, sdd->regs + S3C64XX_SPI_CS_REG);
1009 
1010 	/* Disable Interrupts - we use Polling if not DMA mode */
1011 	writel(0, regs + S3C64XX_SPI_INT_EN);
1012 
1013 	if (!sdd->port_conf->clk_from_cmu)
1014 		writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
1015 				regs + S3C64XX_SPI_CLK_CFG);
1016 	writel(0, regs + S3C64XX_SPI_MODE_CFG);
1017 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
1018 
1019 	/* Clear any irq pending bits, should set and clear the bits */
1020 	val = S3C64XX_SPI_PND_RX_OVERRUN_CLR |
1021 		S3C64XX_SPI_PND_RX_UNDERRUN_CLR |
1022 		S3C64XX_SPI_PND_TX_OVERRUN_CLR |
1023 		S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
1024 	writel(val, regs + S3C64XX_SPI_PENDING_CLR);
1025 	writel(0, regs + S3C64XX_SPI_PENDING_CLR);
1026 
1027 	writel(0, regs + S3C64XX_SPI_SWAP_CFG);
1028 
1029 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
1030 	val &= ~S3C64XX_SPI_MODE_4BURST;
1031 	val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
1032 	val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
1033 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
1034 
1035 	s3c64xx_flush_fifo(sdd);
1036 }
1037 
1038 #ifdef CONFIG_OF
1039 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1040 {
1041 	struct s3c64xx_spi_info *sci;
1042 	u32 temp;
1043 
1044 	sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
1045 	if (!sci)
1046 		return ERR_PTR(-ENOMEM);
1047 
1048 	if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
1049 		dev_warn(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
1050 		sci->src_clk_nr = 0;
1051 	} else {
1052 		sci->src_clk_nr = temp;
1053 	}
1054 
1055 	if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
1056 		dev_warn(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
1057 		sci->num_cs = 1;
1058 	} else {
1059 		sci->num_cs = temp;
1060 	}
1061 
1062 	sci->no_cs = of_property_read_bool(dev->of_node, "no-cs-readback");
1063 
1064 	return sci;
1065 }
1066 #else
1067 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1068 {
1069 	return dev_get_platdata(dev);
1070 }
1071 #endif
1072 
1073 static inline const struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
1074 						struct platform_device *pdev)
1075 {
1076 #ifdef CONFIG_OF
1077 	if (pdev->dev.of_node)
1078 		return of_device_get_match_data(&pdev->dev);
1079 #endif
1080 	return (const struct s3c64xx_spi_port_config *)platform_get_device_id(pdev)->driver_data;
1081 }
1082 
1083 static int s3c64xx_spi_probe(struct platform_device *pdev)
1084 {
1085 	struct resource	*mem_res;
1086 	struct s3c64xx_spi_driver_data *sdd;
1087 	struct s3c64xx_spi_info *sci = dev_get_platdata(&pdev->dev);
1088 	struct spi_master *master;
1089 	int ret, irq;
1090 	char clk_name[16];
1091 
1092 	if (!sci && pdev->dev.of_node) {
1093 		sci = s3c64xx_spi_parse_dt(&pdev->dev);
1094 		if (IS_ERR(sci))
1095 			return PTR_ERR(sci);
1096 	}
1097 
1098 	if (!sci) {
1099 		dev_err(&pdev->dev, "platform_data missing!\n");
1100 		return -ENODEV;
1101 	}
1102 
1103 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1104 	if (mem_res == NULL) {
1105 		dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
1106 		return -ENXIO;
1107 	}
1108 
1109 	irq = platform_get_irq(pdev, 0);
1110 	if (irq < 0) {
1111 		dev_warn(&pdev->dev, "Failed to get IRQ: %d\n", irq);
1112 		return irq;
1113 	}
1114 
1115 	master = spi_alloc_master(&pdev->dev,
1116 				sizeof(struct s3c64xx_spi_driver_data));
1117 	if (master == NULL) {
1118 		dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
1119 		return -ENOMEM;
1120 	}
1121 
1122 	platform_set_drvdata(pdev, master);
1123 
1124 	sdd = spi_master_get_devdata(master);
1125 	sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
1126 	sdd->master = master;
1127 	sdd->cntrlr_info = sci;
1128 	sdd->pdev = pdev;
1129 	sdd->sfr_start = mem_res->start;
1130 	if (pdev->dev.of_node) {
1131 		ret = of_alias_get_id(pdev->dev.of_node, "spi");
1132 		if (ret < 0) {
1133 			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
1134 				ret);
1135 			goto err_deref_master;
1136 		}
1137 		sdd->port_id = ret;
1138 	} else {
1139 		sdd->port_id = pdev->id;
1140 	}
1141 
1142 	sdd->cur_bpw = 8;
1143 
1144 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
1145 	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
1146 
1147 	master->dev.of_node = pdev->dev.of_node;
1148 	master->bus_num = sdd->port_id;
1149 	master->setup = s3c64xx_spi_setup;
1150 	master->cleanup = s3c64xx_spi_cleanup;
1151 	master->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
1152 	master->unprepare_transfer_hardware = s3c64xx_spi_unprepare_transfer;
1153 	master->prepare_message = s3c64xx_spi_prepare_message;
1154 	master->transfer_one = s3c64xx_spi_transfer_one;
1155 	master->num_chipselect = sci->num_cs;
1156 	master->use_gpio_descriptors = true;
1157 	master->dma_alignment = 8;
1158 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
1159 					SPI_BPW_MASK(8);
1160 	/* the spi->mode bits understood by this driver: */
1161 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1162 	if (sdd->port_conf->has_loopback)
1163 		master->mode_bits |= SPI_LOOP;
1164 	master->auto_runtime_pm = true;
1165 	if (!is_polling(sdd))
1166 		master->can_dma = s3c64xx_spi_can_dma;
1167 
1168 	sdd->regs = devm_ioremap_resource(&pdev->dev, mem_res);
1169 	if (IS_ERR(sdd->regs)) {
1170 		ret = PTR_ERR(sdd->regs);
1171 		goto err_deref_master;
1172 	}
1173 
1174 	if (sci->cfg_gpio && sci->cfg_gpio()) {
1175 		dev_err(&pdev->dev, "Unable to config gpio\n");
1176 		ret = -EBUSY;
1177 		goto err_deref_master;
1178 	}
1179 
1180 	/* Setup clocks */
1181 	sdd->clk = devm_clk_get(&pdev->dev, "spi");
1182 	if (IS_ERR(sdd->clk)) {
1183 		dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
1184 		ret = PTR_ERR(sdd->clk);
1185 		goto err_deref_master;
1186 	}
1187 
1188 	ret = clk_prepare_enable(sdd->clk);
1189 	if (ret) {
1190 		dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
1191 		goto err_deref_master;
1192 	}
1193 
1194 	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
1195 	sdd->src_clk = devm_clk_get(&pdev->dev, clk_name);
1196 	if (IS_ERR(sdd->src_clk)) {
1197 		dev_err(&pdev->dev,
1198 			"Unable to acquire clock '%s'\n", clk_name);
1199 		ret = PTR_ERR(sdd->src_clk);
1200 		goto err_disable_clk;
1201 	}
1202 
1203 	ret = clk_prepare_enable(sdd->src_clk);
1204 	if (ret) {
1205 		dev_err(&pdev->dev, "Couldn't enable clock '%s'\n", clk_name);
1206 		goto err_disable_clk;
1207 	}
1208 
1209 	if (sdd->port_conf->clk_ioclk) {
1210 		sdd->ioclk = devm_clk_get(&pdev->dev, "spi_ioclk");
1211 		if (IS_ERR(sdd->ioclk)) {
1212 			dev_err(&pdev->dev, "Unable to acquire 'ioclk'\n");
1213 			ret = PTR_ERR(sdd->ioclk);
1214 			goto err_disable_src_clk;
1215 		}
1216 
1217 		ret = clk_prepare_enable(sdd->ioclk);
1218 		if (ret) {
1219 			dev_err(&pdev->dev, "Couldn't enable clock 'ioclk'\n");
1220 			goto err_disable_src_clk;
1221 		}
1222 	}
1223 
1224 	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1225 	pm_runtime_use_autosuspend(&pdev->dev);
1226 	pm_runtime_set_active(&pdev->dev);
1227 	pm_runtime_enable(&pdev->dev);
1228 	pm_runtime_get_sync(&pdev->dev);
1229 
1230 	/* Setup Deufult Mode */
1231 	s3c64xx_spi_hwinit(sdd);
1232 
1233 	spin_lock_init(&sdd->lock);
1234 	init_completion(&sdd->xfer_completion);
1235 
1236 	ret = devm_request_irq(&pdev->dev, irq, s3c64xx_spi_irq, 0,
1237 				"spi-s3c64xx", sdd);
1238 	if (ret != 0) {
1239 		dev_err(&pdev->dev, "Failed to request IRQ %d: %d\n",
1240 			irq, ret);
1241 		goto err_pm_put;
1242 	}
1243 
1244 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1245 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1246 	       sdd->regs + S3C64XX_SPI_INT_EN);
1247 
1248 	ret = devm_spi_register_master(&pdev->dev, master);
1249 	if (ret != 0) {
1250 		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
1251 		goto err_pm_put;
1252 	}
1253 
1254 	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",
1255 					sdd->port_id, master->num_chipselect);
1256 	dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\n",
1257 					mem_res, (FIFO_LVL_MASK(sdd) >> 1) + 1);
1258 
1259 	pm_runtime_mark_last_busy(&pdev->dev);
1260 	pm_runtime_put_autosuspend(&pdev->dev);
1261 
1262 	return 0;
1263 
1264 err_pm_put:
1265 	pm_runtime_put_noidle(&pdev->dev);
1266 	pm_runtime_disable(&pdev->dev);
1267 	pm_runtime_set_suspended(&pdev->dev);
1268 
1269 	clk_disable_unprepare(sdd->ioclk);
1270 err_disable_src_clk:
1271 	clk_disable_unprepare(sdd->src_clk);
1272 err_disable_clk:
1273 	clk_disable_unprepare(sdd->clk);
1274 err_deref_master:
1275 	spi_master_put(master);
1276 
1277 	return ret;
1278 }
1279 
1280 static int s3c64xx_spi_remove(struct platform_device *pdev)
1281 {
1282 	struct spi_master *master = platform_get_drvdata(pdev);
1283 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1284 
1285 	pm_runtime_get_sync(&pdev->dev);
1286 
1287 	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
1288 
1289 	if (!is_polling(sdd)) {
1290 		dma_release_channel(sdd->rx_dma.ch);
1291 		dma_release_channel(sdd->tx_dma.ch);
1292 	}
1293 
1294 	clk_disable_unprepare(sdd->ioclk);
1295 
1296 	clk_disable_unprepare(sdd->src_clk);
1297 
1298 	clk_disable_unprepare(sdd->clk);
1299 
1300 	pm_runtime_put_noidle(&pdev->dev);
1301 	pm_runtime_disable(&pdev->dev);
1302 	pm_runtime_set_suspended(&pdev->dev);
1303 
1304 	return 0;
1305 }
1306 
1307 #ifdef CONFIG_PM_SLEEP
1308 static int s3c64xx_spi_suspend(struct device *dev)
1309 {
1310 	struct spi_master *master = dev_get_drvdata(dev);
1311 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1312 
1313 	int ret = spi_master_suspend(master);
1314 	if (ret)
1315 		return ret;
1316 
1317 	ret = pm_runtime_force_suspend(dev);
1318 	if (ret < 0)
1319 		return ret;
1320 
1321 	sdd->cur_speed = 0; /* Output Clock is stopped */
1322 
1323 	return 0;
1324 }
1325 
1326 static int s3c64xx_spi_resume(struct device *dev)
1327 {
1328 	struct spi_master *master = dev_get_drvdata(dev);
1329 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1330 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1331 	int ret;
1332 
1333 	if (sci->cfg_gpio)
1334 		sci->cfg_gpio();
1335 
1336 	ret = pm_runtime_force_resume(dev);
1337 	if (ret < 0)
1338 		return ret;
1339 
1340 	return spi_master_resume(master);
1341 }
1342 #endif /* CONFIG_PM_SLEEP */
1343 
1344 #ifdef CONFIG_PM
1345 static int s3c64xx_spi_runtime_suspend(struct device *dev)
1346 {
1347 	struct spi_master *master = dev_get_drvdata(dev);
1348 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1349 
1350 	clk_disable_unprepare(sdd->clk);
1351 	clk_disable_unprepare(sdd->src_clk);
1352 	clk_disable_unprepare(sdd->ioclk);
1353 
1354 	return 0;
1355 }
1356 
1357 static int s3c64xx_spi_runtime_resume(struct device *dev)
1358 {
1359 	struct spi_master *master = dev_get_drvdata(dev);
1360 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1361 	int ret;
1362 
1363 	if (sdd->port_conf->clk_ioclk) {
1364 		ret = clk_prepare_enable(sdd->ioclk);
1365 		if (ret != 0)
1366 			return ret;
1367 	}
1368 
1369 	ret = clk_prepare_enable(sdd->src_clk);
1370 	if (ret != 0)
1371 		goto err_disable_ioclk;
1372 
1373 	ret = clk_prepare_enable(sdd->clk);
1374 	if (ret != 0)
1375 		goto err_disable_src_clk;
1376 
1377 	s3c64xx_spi_hwinit(sdd);
1378 
1379 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1380 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1381 	       sdd->regs + S3C64XX_SPI_INT_EN);
1382 
1383 	return 0;
1384 
1385 err_disable_src_clk:
1386 	clk_disable_unprepare(sdd->src_clk);
1387 err_disable_ioclk:
1388 	clk_disable_unprepare(sdd->ioclk);
1389 
1390 	return ret;
1391 }
1392 #endif /* CONFIG_PM */
1393 
1394 static const struct dev_pm_ops s3c64xx_spi_pm = {
1395 	SET_SYSTEM_SLEEP_PM_OPS(s3c64xx_spi_suspend, s3c64xx_spi_resume)
1396 	SET_RUNTIME_PM_OPS(s3c64xx_spi_runtime_suspend,
1397 			   s3c64xx_spi_runtime_resume, NULL)
1398 };
1399 
1400 static const struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
1401 	.fifo_lvl_mask	= { 0x7f },
1402 	.rx_lvl_offset	= 13,
1403 	.tx_st_done	= 21,
1404 	.clk_div	= 2,
1405 	.high_speed	= true,
1406 };
1407 
1408 static const struct s3c64xx_spi_port_config s3c6410_spi_port_config = {
1409 	.fifo_lvl_mask	= { 0x7f, 0x7F },
1410 	.rx_lvl_offset	= 13,
1411 	.tx_st_done	= 21,
1412 	.clk_div	= 2,
1413 };
1414 
1415 static const struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
1416 	.fifo_lvl_mask	= { 0x1ff, 0x7F },
1417 	.rx_lvl_offset	= 15,
1418 	.tx_st_done	= 25,
1419 	.clk_div	= 2,
1420 	.high_speed	= true,
1421 };
1422 
1423 static const struct s3c64xx_spi_port_config exynos4_spi_port_config = {
1424 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F },
1425 	.rx_lvl_offset	= 15,
1426 	.tx_st_done	= 25,
1427 	.clk_div	= 2,
1428 	.high_speed	= true,
1429 	.clk_from_cmu	= true,
1430 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1431 };
1432 
1433 static const struct s3c64xx_spi_port_config exynos7_spi_port_config = {
1434 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},
1435 	.rx_lvl_offset	= 15,
1436 	.tx_st_done	= 25,
1437 	.clk_div	= 2,
1438 	.high_speed	= true,
1439 	.clk_from_cmu	= true,
1440 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1441 };
1442 
1443 static const struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
1444 	.fifo_lvl_mask	= { 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff},
1445 	.rx_lvl_offset	= 15,
1446 	.tx_st_done	= 25,
1447 	.clk_div	= 2,
1448 	.high_speed	= true,
1449 	.clk_from_cmu	= true,
1450 	.clk_ioclk	= true,
1451 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1452 };
1453 
1454 static const struct s3c64xx_spi_port_config exynosautov9_spi_port_config = {
1455 	.fifo_lvl_mask	= { 0x1ff, 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff, 0x7f,
1456 			    0x7f, 0x7f, 0x7f, 0x7f},
1457 	.rx_lvl_offset	= 15,
1458 	.tx_st_done	= 25,
1459 	.clk_div	= 4,
1460 	.high_speed	= true,
1461 	.clk_from_cmu	= true,
1462 	.clk_ioclk	= true,
1463 	.has_loopback	= true,
1464 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1465 };
1466 
1467 static const struct s3c64xx_spi_port_config fsd_spi_port_config = {
1468 	.fifo_lvl_mask	= { 0x7f, 0x7f, 0x7f, 0x7f, 0x7f},
1469 	.rx_lvl_offset	= 15,
1470 	.tx_st_done	= 25,
1471 	.clk_div	= 2,
1472 	.high_speed	= true,
1473 	.clk_from_cmu	= true,
1474 	.clk_ioclk	= false,
1475 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1476 };
1477 
1478 static const struct platform_device_id s3c64xx_spi_driver_ids[] = {
1479 	{
1480 		.name		= "s3c2443-spi",
1481 		.driver_data	= (kernel_ulong_t)&s3c2443_spi_port_config,
1482 	}, {
1483 		.name		= "s3c6410-spi",
1484 		.driver_data	= (kernel_ulong_t)&s3c6410_spi_port_config,
1485 	},
1486 	{ },
1487 };
1488 
1489 static const struct of_device_id s3c64xx_spi_dt_match[] = {
1490 	{ .compatible = "samsung,s3c2443-spi",
1491 			.data = (void *)&s3c2443_spi_port_config,
1492 	},
1493 	{ .compatible = "samsung,s3c6410-spi",
1494 			.data = (void *)&s3c6410_spi_port_config,
1495 	},
1496 	{ .compatible = "samsung,s5pv210-spi",
1497 			.data = (void *)&s5pv210_spi_port_config,
1498 	},
1499 	{ .compatible = "samsung,exynos4210-spi",
1500 			.data = (void *)&exynos4_spi_port_config,
1501 	},
1502 	{ .compatible = "samsung,exynos7-spi",
1503 			.data = (void *)&exynos7_spi_port_config,
1504 	},
1505 	{ .compatible = "samsung,exynos5433-spi",
1506 			.data = (void *)&exynos5433_spi_port_config,
1507 	},
1508 	{ .compatible = "samsung,exynosautov9-spi",
1509 			.data = (void *)&exynosautov9_spi_port_config,
1510 	},
1511 	{ .compatible = "tesla,fsd-spi",
1512 			.data = (void *)&fsd_spi_port_config,
1513 	},
1514 	{ },
1515 };
1516 MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
1517 
1518 static struct platform_driver s3c64xx_spi_driver = {
1519 	.driver = {
1520 		.name	= "s3c64xx-spi",
1521 		.pm = &s3c64xx_spi_pm,
1522 		.of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
1523 	},
1524 	.probe = s3c64xx_spi_probe,
1525 	.remove = s3c64xx_spi_remove,
1526 	.id_table = s3c64xx_spi_driver_ids,
1527 };
1528 MODULE_ALIAS("platform:s3c64xx-spi");
1529 
1530 module_platform_driver(s3c64xx_spi_driver);
1531 
1532 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1533 MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1534 MODULE_LICENSE("GPL");
1535