xref: /openbmc/linux/drivers/spi/spi-s3c64xx.c (revision 703e7713)
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_CS_AUTO	(1 << 1)
23 #define AUTOSUSPEND_TIMEOUT	2000
24 
25 /* Registers and bit-fields */
26 
27 #define S3C64XX_SPI_CH_CFG		0x00
28 #define S3C64XX_SPI_CLK_CFG		0x04
29 #define S3C64XX_SPI_MODE_CFG		0x08
30 #define S3C64XX_SPI_CS_REG		0x0C
31 #define S3C64XX_SPI_INT_EN		0x10
32 #define S3C64XX_SPI_STATUS		0x14
33 #define S3C64XX_SPI_TX_DATA		0x18
34 #define S3C64XX_SPI_RX_DATA		0x1C
35 #define S3C64XX_SPI_PACKET_CNT		0x20
36 #define S3C64XX_SPI_PENDING_CLR		0x24
37 #define S3C64XX_SPI_SWAP_CFG		0x28
38 #define S3C64XX_SPI_FB_CLK		0x2C
39 
40 #define S3C64XX_SPI_CH_HS_EN		(1<<6)	/* High Speed Enable */
41 #define S3C64XX_SPI_CH_SW_RST		(1<<5)
42 #define S3C64XX_SPI_CH_SLAVE		(1<<4)
43 #define S3C64XX_SPI_CPOL_L		(1<<3)
44 #define S3C64XX_SPI_CPHA_B		(1<<2)
45 #define S3C64XX_SPI_CH_RXCH_ON		(1<<1)
46 #define S3C64XX_SPI_CH_TXCH_ON		(1<<0)
47 
48 #define S3C64XX_SPI_CLKSEL_SRCMSK	(3<<9)
49 #define S3C64XX_SPI_CLKSEL_SRCSHFT	9
50 #define S3C64XX_SPI_ENCLK_ENABLE	(1<<8)
51 #define S3C64XX_SPI_PSR_MASK		0xff
52 
53 #define S3C64XX_SPI_MODE_CH_TSZ_BYTE		(0<<29)
54 #define S3C64XX_SPI_MODE_CH_TSZ_HALFWORD	(1<<29)
55 #define S3C64XX_SPI_MODE_CH_TSZ_WORD		(2<<29)
56 #define S3C64XX_SPI_MODE_CH_TSZ_MASK		(3<<29)
57 #define S3C64XX_SPI_MODE_BUS_TSZ_BYTE		(0<<17)
58 #define S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD	(1<<17)
59 #define S3C64XX_SPI_MODE_BUS_TSZ_WORD		(2<<17)
60 #define S3C64XX_SPI_MODE_BUS_TSZ_MASK		(3<<17)
61 #define S3C64XX_SPI_MODE_RX_RDY_LVL		GENMASK(16, 11)
62 #define S3C64XX_SPI_MODE_RX_RDY_LVL_SHIFT	11
63 #define S3C64XX_SPI_MODE_SELF_LOOPBACK		(1<<3)
64 #define S3C64XX_SPI_MODE_RXDMA_ON		(1<<2)
65 #define S3C64XX_SPI_MODE_TXDMA_ON		(1<<1)
66 #define S3C64XX_SPI_MODE_4BURST			(1<<0)
67 
68 #define S3C64XX_SPI_CS_NSC_CNT_2		(2<<4)
69 #define S3C64XX_SPI_CS_AUTO			(1<<1)
70 #define S3C64XX_SPI_CS_SIG_INACT		(1<<0)
71 
72 #define S3C64XX_SPI_INT_TRAILING_EN		(1<<6)
73 #define S3C64XX_SPI_INT_RX_OVERRUN_EN		(1<<5)
74 #define S3C64XX_SPI_INT_RX_UNDERRUN_EN		(1<<4)
75 #define S3C64XX_SPI_INT_TX_OVERRUN_EN		(1<<3)
76 #define S3C64XX_SPI_INT_TX_UNDERRUN_EN		(1<<2)
77 #define S3C64XX_SPI_INT_RX_FIFORDY_EN		(1<<1)
78 #define S3C64XX_SPI_INT_TX_FIFORDY_EN		(1<<0)
79 
80 #define S3C64XX_SPI_ST_RX_OVERRUN_ERR		(1<<5)
81 #define S3C64XX_SPI_ST_RX_UNDERRUN_ERR		(1<<4)
82 #define S3C64XX_SPI_ST_TX_OVERRUN_ERR		(1<<3)
83 #define S3C64XX_SPI_ST_TX_UNDERRUN_ERR		(1<<2)
84 #define S3C64XX_SPI_ST_RX_FIFORDY		(1<<1)
85 #define S3C64XX_SPI_ST_TX_FIFORDY		(1<<0)
86 
87 #define S3C64XX_SPI_PACKET_CNT_EN		(1<<16)
88 #define S3C64XX_SPI_PACKET_CNT_MASK		GENMASK(15, 0)
89 
90 #define S3C64XX_SPI_PND_TX_UNDERRUN_CLR		(1<<4)
91 #define S3C64XX_SPI_PND_TX_OVERRUN_CLR		(1<<3)
92 #define S3C64XX_SPI_PND_RX_UNDERRUN_CLR		(1<<2)
93 #define S3C64XX_SPI_PND_RX_OVERRUN_CLR		(1<<1)
94 #define S3C64XX_SPI_PND_TRAILING_CLR		(1<<0)
95 
96 #define S3C64XX_SPI_SWAP_RX_HALF_WORD		(1<<7)
97 #define S3C64XX_SPI_SWAP_RX_BYTE		(1<<6)
98 #define S3C64XX_SPI_SWAP_RX_BIT			(1<<5)
99 #define S3C64XX_SPI_SWAP_RX_EN			(1<<4)
100 #define S3C64XX_SPI_SWAP_TX_HALF_WORD		(1<<3)
101 #define S3C64XX_SPI_SWAP_TX_BYTE		(1<<2)
102 #define S3C64XX_SPI_SWAP_TX_BIT			(1<<1)
103 #define S3C64XX_SPI_SWAP_TX_EN			(1<<0)
104 
105 #define S3C64XX_SPI_FBCLK_MSK			(3<<0)
106 
107 #define FIFO_LVL_MASK(i) ((i)->port_conf->fifo_lvl_mask[i->port_id])
108 #define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & \
109 				(1 << (i)->port_conf->tx_st_done)) ? 1 : 0)
110 #define TX_FIFO_LVL(v, i) (((v) >> 6) & FIFO_LVL_MASK(i))
111 #define RX_FIFO_LVL(v, i) (((v) >> (i)->port_conf->rx_lvl_offset) & \
112 					FIFO_LVL_MASK(i))
113 
114 #define S3C64XX_SPI_MAX_TRAILCNT	0x3ff
115 #define S3C64XX_SPI_TRAILCNT_OFF	19
116 
117 #define S3C64XX_SPI_TRAILCNT		S3C64XX_SPI_MAX_TRAILCNT
118 
119 #define S3C64XX_SPI_POLLING_SIZE	32
120 
121 #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
122 #define is_polling(x)	(x->cntrlr_info->polling)
123 
124 #define RXBUSY    (1<<2)
125 #define TXBUSY    (1<<3)
126 
127 struct s3c64xx_spi_dma_data {
128 	struct dma_chan *ch;
129 	dma_cookie_t cookie;
130 	enum dma_transfer_direction direction;
131 };
132 
133 /**
134  * struct s3c64xx_spi_port_config - SPI Controller hardware info
135  * @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
136  * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
137  * @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
138  * @clk_div: Internal clock divider
139  * @quirks: Bitmask of known quirks
140  * @high_speed: True, if the controller supports HIGH_SPEED_EN bit.
141  * @clk_from_cmu: True, if the controller does not include a clock mux and
142  *	prescaler unit.
143  * @clk_ioclk: True if clock is present on this device
144  * @has_loopback: True if loopback mode can be supported
145  *
146  * The Samsung s3c64xx SPI controller are used on various Samsung SoC's but
147  * differ in some aspects such as the size of the fifo and spi bus clock
148  * setup. Such differences are specified to the driver using this structure
149  * which is provided as driver data to the driver.
150  */
151 struct s3c64xx_spi_port_config {
152 	int	fifo_lvl_mask[MAX_SPI_PORTS];
153 	int	rx_lvl_offset;
154 	int	tx_st_done;
155 	int	quirks;
156 	int	clk_div;
157 	bool	high_speed;
158 	bool	clk_from_cmu;
159 	bool	clk_ioclk;
160 	bool	has_loopback;
161 };
162 
163 /**
164  * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
165  * @clk: Pointer to the spi clock.
166  * @src_clk: Pointer to the clock used to generate SPI signals.
167  * @ioclk: Pointer to the i/o clock between master and slave
168  * @pdev: Pointer to device's platform device data
169  * @master: Pointer to the SPI Protocol master.
170  * @cntrlr_info: Platform specific data for the controller this driver manages.
171  * @lock: Controller specific lock.
172  * @state: Set of FLAGS to indicate status.
173  * @sfr_start: BUS address of SPI controller regs.
174  * @regs: Pointer to ioremap'ed controller registers.
175  * @xfer_completion: To indicate completion of xfer task.
176  * @cur_mode: Stores the active configuration of the controller.
177  * @cur_bpw: Stores the active bits per word settings.
178  * @cur_speed: Current clock speed
179  * @rx_dma: Local receive DMA data (e.g. chan and direction)
180  * @tx_dma: Local transmit DMA data (e.g. chan and direction)
181  * @port_conf: Local SPI port configuartion data
182  * @port_id: Port identification number
183  */
184 struct s3c64xx_spi_driver_data {
185 	void __iomem                    *regs;
186 	struct clk                      *clk;
187 	struct clk                      *src_clk;
188 	struct clk                      *ioclk;
189 	struct platform_device          *pdev;
190 	struct spi_master               *master;
191 	struct s3c64xx_spi_info         *cntrlr_info;
192 	spinlock_t                      lock;
193 	unsigned long                   sfr_start;
194 	struct completion               xfer_completion;
195 	unsigned                        state;
196 	unsigned                        cur_mode, cur_bpw;
197 	unsigned                        cur_speed;
198 	struct s3c64xx_spi_dma_data	rx_dma;
199 	struct s3c64xx_spi_dma_data	tx_dma;
200 	const struct s3c64xx_spi_port_config	*port_conf;
201 	unsigned int			port_id;
202 };
203 
204 static void s3c64xx_flush_fifo(struct s3c64xx_spi_driver_data *sdd)
205 {
206 	void __iomem *regs = sdd->regs;
207 	unsigned long loops;
208 	u32 val;
209 
210 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
211 
212 	val = readl(regs + S3C64XX_SPI_CH_CFG);
213 	val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON);
214 	writel(val, regs + S3C64XX_SPI_CH_CFG);
215 
216 	val = readl(regs + S3C64XX_SPI_CH_CFG);
217 	val |= S3C64XX_SPI_CH_SW_RST;
218 	val &= ~S3C64XX_SPI_CH_HS_EN;
219 	writel(val, regs + S3C64XX_SPI_CH_CFG);
220 
221 	/* Flush TxFIFO*/
222 	loops = msecs_to_loops(1);
223 	do {
224 		val = readl(regs + S3C64XX_SPI_STATUS);
225 	} while (TX_FIFO_LVL(val, sdd) && loops--);
226 
227 	if (loops == 0)
228 		dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n");
229 
230 	/* Flush RxFIFO*/
231 	loops = msecs_to_loops(1);
232 	do {
233 		val = readl(regs + S3C64XX_SPI_STATUS);
234 		if (RX_FIFO_LVL(val, sdd))
235 			readl(regs + S3C64XX_SPI_RX_DATA);
236 		else
237 			break;
238 	} while (loops--);
239 
240 	if (loops == 0)
241 		dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n");
242 
243 	val = readl(regs + S3C64XX_SPI_CH_CFG);
244 	val &= ~S3C64XX_SPI_CH_SW_RST;
245 	writel(val, regs + S3C64XX_SPI_CH_CFG);
246 
247 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
248 	val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
249 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
250 }
251 
252 static void s3c64xx_spi_dmacb(void *data)
253 {
254 	struct s3c64xx_spi_driver_data *sdd;
255 	struct s3c64xx_spi_dma_data *dma = data;
256 	unsigned long flags;
257 
258 	if (dma->direction == DMA_DEV_TO_MEM)
259 		sdd = container_of(data,
260 			struct s3c64xx_spi_driver_data, rx_dma);
261 	else
262 		sdd = container_of(data,
263 			struct s3c64xx_spi_driver_data, tx_dma);
264 
265 	spin_lock_irqsave(&sdd->lock, flags);
266 
267 	if (dma->direction == DMA_DEV_TO_MEM) {
268 		sdd->state &= ~RXBUSY;
269 		if (!(sdd->state & TXBUSY))
270 			complete(&sdd->xfer_completion);
271 	} else {
272 		sdd->state &= ~TXBUSY;
273 		if (!(sdd->state & RXBUSY))
274 			complete(&sdd->xfer_completion);
275 	}
276 
277 	spin_unlock_irqrestore(&sdd->lock, flags);
278 }
279 
280 static int prepare_dma(struct s3c64xx_spi_dma_data *dma,
281 			struct sg_table *sgt)
282 {
283 	struct s3c64xx_spi_driver_data *sdd;
284 	struct dma_slave_config config;
285 	struct dma_async_tx_descriptor *desc;
286 	int ret;
287 
288 	memset(&config, 0, sizeof(config));
289 
290 	if (dma->direction == DMA_DEV_TO_MEM) {
291 		sdd = container_of((void *)dma,
292 			struct s3c64xx_spi_driver_data, rx_dma);
293 		config.direction = dma->direction;
294 		config.src_addr = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
295 		config.src_addr_width = sdd->cur_bpw / 8;
296 		config.src_maxburst = 1;
297 		dmaengine_slave_config(dma->ch, &config);
298 	} else {
299 		sdd = container_of((void *)dma,
300 			struct s3c64xx_spi_driver_data, tx_dma);
301 		config.direction = dma->direction;
302 		config.dst_addr = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
303 		config.dst_addr_width = sdd->cur_bpw / 8;
304 		config.dst_maxburst = 1;
305 		dmaengine_slave_config(dma->ch, &config);
306 	}
307 
308 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
309 				       dma->direction, DMA_PREP_INTERRUPT);
310 	if (!desc) {
311 		dev_err(&sdd->pdev->dev, "unable to prepare %s scatterlist",
312 			dma->direction == DMA_DEV_TO_MEM ? "rx" : "tx");
313 		return -ENOMEM;
314 	}
315 
316 	desc->callback = s3c64xx_spi_dmacb;
317 	desc->callback_param = dma;
318 
319 	dma->cookie = dmaengine_submit(desc);
320 	ret = dma_submit_error(dma->cookie);
321 	if (ret) {
322 		dev_err(&sdd->pdev->dev, "DMA submission failed");
323 		return -EIO;
324 	}
325 
326 	dma_async_issue_pending(dma->ch);
327 	return 0;
328 }
329 
330 static void s3c64xx_spi_set_cs(struct spi_device *spi, bool enable)
331 {
332 	struct s3c64xx_spi_driver_data *sdd =
333 					spi_master_get_devdata(spi->master);
334 
335 	if (sdd->cntrlr_info->no_cs)
336 		return;
337 
338 	if (enable) {
339 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO)) {
340 			writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
341 		} else {
342 			u32 ssel = readl(sdd->regs + S3C64XX_SPI_CS_REG);
343 
344 			ssel |= (S3C64XX_SPI_CS_AUTO |
345 						S3C64XX_SPI_CS_NSC_CNT_2);
346 			writel(ssel, sdd->regs + S3C64XX_SPI_CS_REG);
347 		}
348 	} else {
349 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
350 			writel(S3C64XX_SPI_CS_SIG_INACT,
351 			       sdd->regs + S3C64XX_SPI_CS_REG);
352 	}
353 }
354 
355 static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
356 {
357 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
358 
359 	if (is_polling(sdd))
360 		return 0;
361 
362 	/* Requests DMA channels */
363 	sdd->rx_dma.ch = dma_request_chan(&sdd->pdev->dev, "rx");
364 	if (IS_ERR(sdd->rx_dma.ch)) {
365 		dev_err(&sdd->pdev->dev, "Failed to get RX DMA channel\n");
366 		sdd->rx_dma.ch = NULL;
367 		return 0;
368 	}
369 
370 	sdd->tx_dma.ch = dma_request_chan(&sdd->pdev->dev, "tx");
371 	if (IS_ERR(sdd->tx_dma.ch)) {
372 		dev_err(&sdd->pdev->dev, "Failed to get TX DMA channel\n");
373 		dma_release_channel(sdd->rx_dma.ch);
374 		sdd->tx_dma.ch = NULL;
375 		sdd->rx_dma.ch = NULL;
376 		return 0;
377 	}
378 
379 	spi->dma_rx = sdd->rx_dma.ch;
380 	spi->dma_tx = sdd->tx_dma.ch;
381 
382 	return 0;
383 }
384 
385 static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
386 {
387 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
388 
389 	if (is_polling(sdd))
390 		return 0;
391 
392 	/* Releases DMA channels if they are allocated */
393 	if (sdd->rx_dma.ch && sdd->tx_dma.ch) {
394 		dma_release_channel(sdd->rx_dma.ch);
395 		dma_release_channel(sdd->tx_dma.ch);
396 		sdd->rx_dma.ch = NULL;
397 		sdd->tx_dma.ch = NULL;
398 	}
399 
400 	return 0;
401 }
402 
403 static bool s3c64xx_spi_can_dma(struct spi_master *master,
404 				struct spi_device *spi,
405 				struct spi_transfer *xfer)
406 {
407 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
408 
409 	if (sdd->rx_dma.ch && sdd->tx_dma.ch) {
410 		return xfer->len > (FIFO_LVL_MASK(sdd) >> 1) + 1;
411 	} else {
412 		return false;
413 	}
414 
415 }
416 
417 static int s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
418 				    struct spi_transfer *xfer, int dma_mode)
419 {
420 	void __iomem *regs = sdd->regs;
421 	u32 modecfg, chcfg;
422 	int ret = 0;
423 
424 	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
425 	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
426 
427 	chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
428 	chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
429 
430 	if (dma_mode) {
431 		chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
432 	} else {
433 		/* Always shift in data in FIFO, even if xfer is Tx only,
434 		 * this helps setting PCKT_CNT value for generating clocks
435 		 * as exactly needed.
436 		 */
437 		chcfg |= S3C64XX_SPI_CH_RXCH_ON;
438 		writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
439 					| S3C64XX_SPI_PACKET_CNT_EN,
440 					regs + S3C64XX_SPI_PACKET_CNT);
441 	}
442 
443 	if (xfer->tx_buf != NULL) {
444 		sdd->state |= TXBUSY;
445 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
446 		if (dma_mode) {
447 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
448 			ret = prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
449 		} else {
450 			switch (sdd->cur_bpw) {
451 			case 32:
452 				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
453 					xfer->tx_buf, xfer->len / 4);
454 				break;
455 			case 16:
456 				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
457 					xfer->tx_buf, xfer->len / 2);
458 				break;
459 			default:
460 				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
461 					xfer->tx_buf, xfer->len);
462 				break;
463 			}
464 		}
465 	}
466 
467 	if (xfer->rx_buf != NULL) {
468 		sdd->state |= RXBUSY;
469 
470 		if (sdd->port_conf->high_speed && sdd->cur_speed >= 30000000UL
471 					&& !(sdd->cur_mode & SPI_CPHA))
472 			chcfg |= S3C64XX_SPI_CH_HS_EN;
473 
474 		if (dma_mode) {
475 			modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
476 			chcfg |= S3C64XX_SPI_CH_RXCH_ON;
477 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
478 					| S3C64XX_SPI_PACKET_CNT_EN,
479 					regs + S3C64XX_SPI_PACKET_CNT);
480 			ret = prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
481 		}
482 	}
483 
484 	if (ret)
485 		return ret;
486 
487 	writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
488 	writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
489 
490 	return 0;
491 }
492 
493 static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
494 					int timeout_ms)
495 {
496 	void __iomem *regs = sdd->regs;
497 	unsigned long val = 1;
498 	u32 status;
499 
500 	/* max fifo depth available */
501 	u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
502 
503 	if (timeout_ms)
504 		val = msecs_to_loops(timeout_ms);
505 
506 	do {
507 		status = readl(regs + S3C64XX_SPI_STATUS);
508 	} while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
509 
510 	/* return the actual received data length */
511 	return RX_FIFO_LVL(status, sdd);
512 }
513 
514 static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
515 				struct spi_transfer *xfer)
516 {
517 	void __iomem *regs = sdd->regs;
518 	unsigned long val;
519 	u32 status;
520 	int ms;
521 
522 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
523 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
524 	ms += 30;               /* some tolerance */
525 	ms = max(ms, 100);      /* minimum timeout */
526 
527 	val = msecs_to_jiffies(ms) + 10;
528 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
529 
530 	/*
531 	 * If the previous xfer was completed within timeout, then
532 	 * proceed further else return -EIO.
533 	 * DmaTx returns after simply writing data in the FIFO,
534 	 * w/o waiting for real transmission on the bus to finish.
535 	 * DmaRx returns only after Dma read data from FIFO which
536 	 * needs bus transmission to finish, so we don't worry if
537 	 * Xfer involved Rx(with or without Tx).
538 	 */
539 	if (val && !xfer->rx_buf) {
540 		val = msecs_to_loops(10);
541 		status = readl(regs + S3C64XX_SPI_STATUS);
542 		while ((TX_FIFO_LVL(status, sdd)
543 			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
544 		       && --val) {
545 			cpu_relax();
546 			status = readl(regs + S3C64XX_SPI_STATUS);
547 		}
548 
549 	}
550 
551 	/* If timed out while checking rx/tx status return error */
552 	if (!val)
553 		return -EIO;
554 
555 	return 0;
556 }
557 
558 static int s3c64xx_wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
559 				struct spi_transfer *xfer, bool use_irq)
560 {
561 	void __iomem *regs = sdd->regs;
562 	unsigned long val;
563 	u32 status;
564 	int loops;
565 	u32 cpy_len;
566 	u8 *buf;
567 	int ms;
568 	unsigned long time_us;
569 
570 	/* microsecs to xfer 'len' bytes @ 'cur_speed' */
571 	time_us = (xfer->len * 8 * 1000 * 1000) / sdd->cur_speed;
572 	ms = (time_us / 1000);
573 	ms += 10; /* some tolerance */
574 
575 	/* sleep during signal transfer time */
576 	status = readl(regs + S3C64XX_SPI_STATUS);
577 	if (RX_FIFO_LVL(status, sdd) < xfer->len)
578 		usleep_range(time_us / 2, time_us);
579 
580 	if (use_irq) {
581 		val = msecs_to_jiffies(ms);
582 		if (!wait_for_completion_timeout(&sdd->xfer_completion, val))
583 			return -EIO;
584 	}
585 
586 	val = msecs_to_loops(ms);
587 	do {
588 		status = readl(regs + S3C64XX_SPI_STATUS);
589 	} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
590 
591 	if (!val)
592 		return -EIO;
593 
594 	/* If it was only Tx */
595 	if (!xfer->rx_buf) {
596 		sdd->state &= ~TXBUSY;
597 		return 0;
598 	}
599 
600 	/*
601 	 * If the receive length is bigger than the controller fifo
602 	 * size, calculate the loops and read the fifo as many times.
603 	 * loops = length / max fifo size (calculated by using the
604 	 * fifo mask).
605 	 * For any size less than the fifo size the below code is
606 	 * executed atleast once.
607 	 */
608 	loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
609 	buf = xfer->rx_buf;
610 	do {
611 		/* wait for data to be received in the fifo */
612 		cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
613 						       (loops ? ms : 0));
614 
615 		switch (sdd->cur_bpw) {
616 		case 32:
617 			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
618 				     buf, cpy_len / 4);
619 			break;
620 		case 16:
621 			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
622 				     buf, cpy_len / 2);
623 			break;
624 		default:
625 			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
626 				    buf, cpy_len);
627 			break;
628 		}
629 
630 		buf = buf + cpy_len;
631 	} while (loops--);
632 	sdd->state &= ~RXBUSY;
633 
634 	return 0;
635 }
636 
637 static int s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
638 {
639 	void __iomem *regs = sdd->regs;
640 	int ret;
641 	u32 val;
642 	int div = sdd->port_conf->clk_div;
643 
644 	/* Disable Clock */
645 	if (!sdd->port_conf->clk_from_cmu) {
646 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
647 		val &= ~S3C64XX_SPI_ENCLK_ENABLE;
648 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
649 	}
650 
651 	/* Set Polarity and Phase */
652 	val = readl(regs + S3C64XX_SPI_CH_CFG);
653 	val &= ~(S3C64XX_SPI_CH_SLAVE |
654 			S3C64XX_SPI_CPOL_L |
655 			S3C64XX_SPI_CPHA_B);
656 
657 	if (sdd->cur_mode & SPI_CPOL)
658 		val |= S3C64XX_SPI_CPOL_L;
659 
660 	if (sdd->cur_mode & SPI_CPHA)
661 		val |= S3C64XX_SPI_CPHA_B;
662 
663 	writel(val, regs + S3C64XX_SPI_CH_CFG);
664 
665 	/* Set Channel & DMA Mode */
666 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
667 	val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
668 			| S3C64XX_SPI_MODE_CH_TSZ_MASK);
669 
670 	switch (sdd->cur_bpw) {
671 	case 32:
672 		val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
673 		val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;
674 		break;
675 	case 16:
676 		val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
677 		val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;
678 		break;
679 	default:
680 		val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
681 		val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;
682 		break;
683 	}
684 
685 	if ((sdd->cur_mode & SPI_LOOP) && sdd->port_conf->has_loopback)
686 		val |= S3C64XX_SPI_MODE_SELF_LOOPBACK;
687 
688 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
689 
690 	if (sdd->port_conf->clk_from_cmu) {
691 		ret = clk_set_rate(sdd->src_clk, sdd->cur_speed * div);
692 		if (ret)
693 			return ret;
694 		sdd->cur_speed = clk_get_rate(sdd->src_clk) / div;
695 	} else {
696 		/* Configure Clock */
697 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
698 		val &= ~S3C64XX_SPI_PSR_MASK;
699 		val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / div - 1)
700 				& S3C64XX_SPI_PSR_MASK);
701 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
702 
703 		/* Enable Clock */
704 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
705 		val |= S3C64XX_SPI_ENCLK_ENABLE;
706 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
707 	}
708 
709 	return 0;
710 }
711 
712 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
713 
714 static int s3c64xx_spi_prepare_message(struct spi_master *master,
715 				       struct spi_message *msg)
716 {
717 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
718 	struct spi_device *spi = msg->spi;
719 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
720 
721 	/* Configure feedback delay */
722 	if (!cs)
723 		/* No delay if not defined */
724 		writel(0, sdd->regs + S3C64XX_SPI_FB_CLK);
725 	else
726 		writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
727 
728 	return 0;
729 }
730 
731 static size_t s3c64xx_spi_max_transfer_size(struct spi_device *spi)
732 {
733 	struct spi_controller *ctlr = spi->controller;
734 
735 	return ctlr->can_dma ? S3C64XX_SPI_PACKET_CNT_MASK : SIZE_MAX;
736 }
737 
738 static int s3c64xx_spi_transfer_one(struct spi_master *master,
739 				    struct spi_device *spi,
740 				    struct spi_transfer *xfer)
741 {
742 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
743 	const unsigned int fifo_len = (FIFO_LVL_MASK(sdd) >> 1) + 1;
744 	const void *tx_buf = NULL;
745 	void *rx_buf = NULL;
746 	int target_len = 0, origin_len = 0;
747 	int use_dma = 0;
748 	bool use_irq = false;
749 	int status;
750 	u32 speed;
751 	u8 bpw;
752 	unsigned long flags;
753 	u32 rdy_lv;
754 	u32 val;
755 
756 	reinit_completion(&sdd->xfer_completion);
757 
758 	/* Only BPW and Speed may change across transfers */
759 	bpw = xfer->bits_per_word;
760 	speed = xfer->speed_hz;
761 
762 	if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
763 		sdd->cur_bpw = bpw;
764 		sdd->cur_speed = speed;
765 		sdd->cur_mode = spi->mode;
766 		status = s3c64xx_spi_config(sdd);
767 		if (status)
768 			return status;
769 	}
770 
771 	if (!is_polling(sdd) && (xfer->len > fifo_len) &&
772 	    sdd->rx_dma.ch && sdd->tx_dma.ch) {
773 		use_dma = 1;
774 
775 	} else if (xfer->len >= fifo_len) {
776 		tx_buf = xfer->tx_buf;
777 		rx_buf = xfer->rx_buf;
778 		origin_len = xfer->len;
779 		target_len = xfer->len;
780 		xfer->len = fifo_len - 1;
781 	}
782 
783 	do {
784 		/* transfer size is greater than 32, change to IRQ mode */
785 		if (!use_dma && xfer->len > S3C64XX_SPI_POLLING_SIZE)
786 			use_irq = true;
787 
788 		if (use_irq) {
789 			reinit_completion(&sdd->xfer_completion);
790 
791 			rdy_lv = xfer->len;
792 			/* Setup RDY_FIFO trigger Level
793 			 * RDY_LVL =
794 			 * fifo_lvl up to 64 byte -> N bytes
795 			 *               128 byte -> RDY_LVL * 2 bytes
796 			 *               256 byte -> RDY_LVL * 4 bytes
797 			 */
798 			if (fifo_len == 128)
799 				rdy_lv /= 2;
800 			else if (fifo_len == 256)
801 				rdy_lv /= 4;
802 
803 			val = readl(sdd->regs + S3C64XX_SPI_MODE_CFG);
804 			val &= ~S3C64XX_SPI_MODE_RX_RDY_LVL;
805 			val |= (rdy_lv << S3C64XX_SPI_MODE_RX_RDY_LVL_SHIFT);
806 			writel(val, sdd->regs + S3C64XX_SPI_MODE_CFG);
807 
808 			/* Enable FIFO_RDY_EN IRQ */
809 			val = readl(sdd->regs + S3C64XX_SPI_INT_EN);
810 			writel((val | S3C64XX_SPI_INT_RX_FIFORDY_EN),
811 					sdd->regs + S3C64XX_SPI_INT_EN);
812 
813 		}
814 
815 		spin_lock_irqsave(&sdd->lock, flags);
816 
817 		/* Pending only which is to be done */
818 		sdd->state &= ~RXBUSY;
819 		sdd->state &= ~TXBUSY;
820 
821 		/* Start the signals */
822 		s3c64xx_spi_set_cs(spi, true);
823 
824 		status = s3c64xx_enable_datapath(sdd, xfer, use_dma);
825 
826 		spin_unlock_irqrestore(&sdd->lock, flags);
827 
828 		if (status) {
829 			dev_err(&spi->dev, "failed to enable data path for transfer: %d\n", status);
830 			break;
831 		}
832 
833 		if (use_dma)
834 			status = s3c64xx_wait_for_dma(sdd, xfer);
835 		else
836 			status = s3c64xx_wait_for_pio(sdd, xfer, use_irq);
837 
838 		if (status) {
839 			dev_err(&spi->dev,
840 				"I/O Error: rx-%d tx-%d rx-%c tx-%c len-%d dma-%d res-(%d)\n",
841 				xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
842 				(sdd->state & RXBUSY) ? 'f' : 'p',
843 				(sdd->state & TXBUSY) ? 'f' : 'p',
844 				xfer->len, use_dma ? 1 : 0, status);
845 
846 			if (use_dma) {
847 				struct dma_tx_state s;
848 
849 				if (xfer->tx_buf && (sdd->state & TXBUSY)) {
850 					dmaengine_pause(sdd->tx_dma.ch);
851 					dmaengine_tx_status(sdd->tx_dma.ch, sdd->tx_dma.cookie, &s);
852 					dmaengine_terminate_all(sdd->tx_dma.ch);
853 					dev_err(&spi->dev, "TX residue: %d\n", s.residue);
854 
855 				}
856 				if (xfer->rx_buf && (sdd->state & RXBUSY)) {
857 					dmaengine_pause(sdd->rx_dma.ch);
858 					dmaengine_tx_status(sdd->rx_dma.ch, sdd->rx_dma.cookie, &s);
859 					dmaengine_terminate_all(sdd->rx_dma.ch);
860 					dev_err(&spi->dev, "RX residue: %d\n", s.residue);
861 				}
862 			}
863 		} else {
864 			s3c64xx_flush_fifo(sdd);
865 		}
866 		if (target_len > 0) {
867 			target_len -= xfer->len;
868 
869 			if (xfer->tx_buf)
870 				xfer->tx_buf += xfer->len;
871 
872 			if (xfer->rx_buf)
873 				xfer->rx_buf += xfer->len;
874 
875 			if (target_len >= fifo_len)
876 				xfer->len = fifo_len - 1;
877 			else
878 				xfer->len = target_len;
879 		}
880 	} while (target_len > 0);
881 
882 	if (origin_len) {
883 		/* Restore original xfer buffers and length */
884 		xfer->tx_buf = tx_buf;
885 		xfer->rx_buf = rx_buf;
886 		xfer->len = origin_len;
887 	}
888 
889 	return status;
890 }
891 
892 static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
893 				struct spi_device *spi)
894 {
895 	struct s3c64xx_spi_csinfo *cs;
896 	struct device_node *slave_np, *data_np = NULL;
897 	u32 fb_delay = 0;
898 
899 	slave_np = spi->dev.of_node;
900 	if (!slave_np) {
901 		dev_err(&spi->dev, "device node not found\n");
902 		return ERR_PTR(-EINVAL);
903 	}
904 
905 	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
906 	if (!cs)
907 		return ERR_PTR(-ENOMEM);
908 
909 	data_np = of_get_child_by_name(slave_np, "controller-data");
910 	if (!data_np) {
911 		dev_info(&spi->dev, "feedback delay set to default (0)\n");
912 		return cs;
913 	}
914 
915 	of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
916 	cs->fb_delay = fb_delay;
917 	of_node_put(data_np);
918 	return cs;
919 }
920 
921 /*
922  * Here we only check the validity of requested configuration
923  * and save the configuration in a local data-structure.
924  * The controller is actually configured only just before we
925  * get a message to transfer.
926  */
927 static int s3c64xx_spi_setup(struct spi_device *spi)
928 {
929 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
930 	struct s3c64xx_spi_driver_data *sdd;
931 	int err;
932 	int div;
933 
934 	sdd = spi_master_get_devdata(spi->master);
935 	if (spi->dev.of_node) {
936 		cs = s3c64xx_get_slave_ctrldata(spi);
937 		spi->controller_data = cs;
938 	}
939 
940 	/* NULL is fine, we just avoid using the FB delay (=0) */
941 	if (IS_ERR(cs)) {
942 		dev_err(&spi->dev, "No CS for SPI(%d)\n", spi_get_chipselect(spi, 0));
943 		return -ENODEV;
944 	}
945 
946 	if (!spi_get_ctldata(spi))
947 		spi_set_ctldata(spi, cs);
948 
949 	pm_runtime_get_sync(&sdd->pdev->dev);
950 
951 	div = sdd->port_conf->clk_div;
952 
953 	/* Check if we can provide the requested rate */
954 	if (!sdd->port_conf->clk_from_cmu) {
955 		u32 psr, speed;
956 
957 		/* Max possible */
958 		speed = clk_get_rate(sdd->src_clk) / div / (0 + 1);
959 
960 		if (spi->max_speed_hz > speed)
961 			spi->max_speed_hz = speed;
962 
963 		psr = clk_get_rate(sdd->src_clk) / div / spi->max_speed_hz - 1;
964 		psr &= S3C64XX_SPI_PSR_MASK;
965 		if (psr == S3C64XX_SPI_PSR_MASK)
966 			psr--;
967 
968 		speed = clk_get_rate(sdd->src_clk) / div / (psr + 1);
969 		if (spi->max_speed_hz < speed) {
970 			if (psr+1 < S3C64XX_SPI_PSR_MASK) {
971 				psr++;
972 			} else {
973 				err = -EINVAL;
974 				goto setup_exit;
975 			}
976 		}
977 
978 		speed = clk_get_rate(sdd->src_clk) / div / (psr + 1);
979 		if (spi->max_speed_hz >= speed) {
980 			spi->max_speed_hz = speed;
981 		} else {
982 			dev_err(&spi->dev, "Can't set %dHz transfer speed\n",
983 				spi->max_speed_hz);
984 			err = -EINVAL;
985 			goto setup_exit;
986 		}
987 	}
988 
989 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
990 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
991 	s3c64xx_spi_set_cs(spi, false);
992 
993 	return 0;
994 
995 setup_exit:
996 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
997 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
998 	/* setup() returns with device de-selected */
999 	s3c64xx_spi_set_cs(spi, false);
1000 
1001 	spi_set_ctldata(spi, NULL);
1002 
1003 	/* This was dynamically allocated on the DT path */
1004 	if (spi->dev.of_node)
1005 		kfree(cs);
1006 
1007 	return err;
1008 }
1009 
1010 static void s3c64xx_spi_cleanup(struct spi_device *spi)
1011 {
1012 	struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
1013 
1014 	/* This was dynamically allocated on the DT path */
1015 	if (spi->dev.of_node)
1016 		kfree(cs);
1017 
1018 	spi_set_ctldata(spi, NULL);
1019 }
1020 
1021 static irqreturn_t s3c64xx_spi_irq(int irq, void *data)
1022 {
1023 	struct s3c64xx_spi_driver_data *sdd = data;
1024 	struct spi_master *spi = sdd->master;
1025 	unsigned int val, clr = 0;
1026 
1027 	val = readl(sdd->regs + S3C64XX_SPI_STATUS);
1028 
1029 	if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) {
1030 		clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR;
1031 		dev_err(&spi->dev, "RX overrun\n");
1032 	}
1033 	if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) {
1034 		clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR;
1035 		dev_err(&spi->dev, "RX underrun\n");
1036 	}
1037 	if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) {
1038 		clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR;
1039 		dev_err(&spi->dev, "TX overrun\n");
1040 	}
1041 	if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) {
1042 		clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
1043 		dev_err(&spi->dev, "TX underrun\n");
1044 	}
1045 
1046 	if (val & S3C64XX_SPI_ST_RX_FIFORDY) {
1047 		complete(&sdd->xfer_completion);
1048 		/* No pending clear irq, turn-off INT_EN_RX_FIFO_RDY */
1049 		val = readl(sdd->regs + S3C64XX_SPI_INT_EN);
1050 		writel((val & ~S3C64XX_SPI_INT_RX_FIFORDY_EN),
1051 				sdd->regs + S3C64XX_SPI_INT_EN);
1052 	}
1053 
1054 	/* Clear the pending irq by setting and then clearing it */
1055 	writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR);
1056 	writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR);
1057 
1058 	return IRQ_HANDLED;
1059 }
1060 
1061 static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd)
1062 {
1063 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1064 	void __iomem *regs = sdd->regs;
1065 	unsigned int val;
1066 
1067 	sdd->cur_speed = 0;
1068 
1069 	if (sci->no_cs)
1070 		writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
1071 	else if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
1072 		writel(S3C64XX_SPI_CS_SIG_INACT, sdd->regs + S3C64XX_SPI_CS_REG);
1073 
1074 	/* Disable Interrupts - we use Polling if not DMA mode */
1075 	writel(0, regs + S3C64XX_SPI_INT_EN);
1076 
1077 	if (!sdd->port_conf->clk_from_cmu)
1078 		writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
1079 				regs + S3C64XX_SPI_CLK_CFG);
1080 	writel(0, regs + S3C64XX_SPI_MODE_CFG);
1081 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
1082 
1083 	/* Clear any irq pending bits, should set and clear the bits */
1084 	val = S3C64XX_SPI_PND_RX_OVERRUN_CLR |
1085 		S3C64XX_SPI_PND_RX_UNDERRUN_CLR |
1086 		S3C64XX_SPI_PND_TX_OVERRUN_CLR |
1087 		S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
1088 	writel(val, regs + S3C64XX_SPI_PENDING_CLR);
1089 	writel(0, regs + S3C64XX_SPI_PENDING_CLR);
1090 
1091 	writel(0, regs + S3C64XX_SPI_SWAP_CFG);
1092 
1093 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
1094 	val &= ~S3C64XX_SPI_MODE_4BURST;
1095 	val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
1096 	val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
1097 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
1098 
1099 	s3c64xx_flush_fifo(sdd);
1100 }
1101 
1102 #ifdef CONFIG_OF
1103 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1104 {
1105 	struct s3c64xx_spi_info *sci;
1106 	u32 temp;
1107 
1108 	sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
1109 	if (!sci)
1110 		return ERR_PTR(-ENOMEM);
1111 
1112 	if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
1113 		dev_warn(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
1114 		sci->src_clk_nr = 0;
1115 	} else {
1116 		sci->src_clk_nr = temp;
1117 	}
1118 
1119 	if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
1120 		dev_warn(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
1121 		sci->num_cs = 1;
1122 	} else {
1123 		sci->num_cs = temp;
1124 	}
1125 
1126 	sci->no_cs = of_property_read_bool(dev->of_node, "no-cs-readback");
1127 	sci->polling = !of_property_present(dev->of_node, "dmas");
1128 
1129 	return sci;
1130 }
1131 #else
1132 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1133 {
1134 	return dev_get_platdata(dev);
1135 }
1136 #endif
1137 
1138 static inline const struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
1139 						struct platform_device *pdev)
1140 {
1141 #ifdef CONFIG_OF
1142 	if (pdev->dev.of_node)
1143 		return of_device_get_match_data(&pdev->dev);
1144 #endif
1145 	return (const struct s3c64xx_spi_port_config *)platform_get_device_id(pdev)->driver_data;
1146 }
1147 
1148 static int s3c64xx_spi_probe(struct platform_device *pdev)
1149 {
1150 	struct resource	*mem_res;
1151 	struct s3c64xx_spi_driver_data *sdd;
1152 	struct s3c64xx_spi_info *sci = dev_get_platdata(&pdev->dev);
1153 	struct spi_master *master;
1154 	int ret, irq;
1155 	char clk_name[16];
1156 
1157 	if (!sci && pdev->dev.of_node) {
1158 		sci = s3c64xx_spi_parse_dt(&pdev->dev);
1159 		if (IS_ERR(sci))
1160 			return PTR_ERR(sci);
1161 	}
1162 
1163 	if (!sci)
1164 		return dev_err_probe(&pdev->dev, -ENODEV,
1165 				     "Platform_data missing!\n");
1166 
1167 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1168 	if (!mem_res)
1169 		return dev_err_probe(&pdev->dev, -ENXIO,
1170 				     "Unable to get SPI MEM resource\n");
1171 
1172 	irq = platform_get_irq(pdev, 0);
1173 	if (irq < 0)
1174 		return dev_err_probe(&pdev->dev, irq, "Failed to get IRQ\n");
1175 
1176 	master = devm_spi_alloc_master(&pdev->dev, sizeof(*sdd));
1177 	if (!master)
1178 		return dev_err_probe(&pdev->dev, -ENOMEM,
1179 				     "Unable to allocate SPI Master\n");
1180 
1181 	platform_set_drvdata(pdev, master);
1182 
1183 	sdd = spi_master_get_devdata(master);
1184 	sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
1185 	sdd->master = master;
1186 	sdd->cntrlr_info = sci;
1187 	sdd->pdev = pdev;
1188 	sdd->sfr_start = mem_res->start;
1189 	if (pdev->dev.of_node) {
1190 		ret = of_alias_get_id(pdev->dev.of_node, "spi");
1191 		if (ret < 0)
1192 			return dev_err_probe(&pdev->dev, ret,
1193 					     "Failed to get alias id\n");
1194 		sdd->port_id = ret;
1195 	} else {
1196 		sdd->port_id = pdev->id;
1197 	}
1198 
1199 	sdd->cur_bpw = 8;
1200 
1201 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
1202 	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
1203 
1204 	master->dev.of_node = pdev->dev.of_node;
1205 	master->bus_num = sdd->port_id;
1206 	master->setup = s3c64xx_spi_setup;
1207 	master->cleanup = s3c64xx_spi_cleanup;
1208 	master->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
1209 	master->unprepare_transfer_hardware = s3c64xx_spi_unprepare_transfer;
1210 	master->prepare_message = s3c64xx_spi_prepare_message;
1211 	master->transfer_one = s3c64xx_spi_transfer_one;
1212 	master->max_transfer_size = s3c64xx_spi_max_transfer_size;
1213 	master->num_chipselect = sci->num_cs;
1214 	master->use_gpio_descriptors = true;
1215 	master->dma_alignment = 8;
1216 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
1217 					SPI_BPW_MASK(8);
1218 	/* the spi->mode bits understood by this driver: */
1219 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1220 	if (sdd->port_conf->has_loopback)
1221 		master->mode_bits |= SPI_LOOP;
1222 	master->auto_runtime_pm = true;
1223 	if (!is_polling(sdd))
1224 		master->can_dma = s3c64xx_spi_can_dma;
1225 
1226 	sdd->regs = devm_ioremap_resource(&pdev->dev, mem_res);
1227 	if (IS_ERR(sdd->regs))
1228 		return PTR_ERR(sdd->regs);
1229 
1230 	if (sci->cfg_gpio && sci->cfg_gpio())
1231 		return dev_err_probe(&pdev->dev, -EBUSY,
1232 				     "Unable to config gpio\n");
1233 
1234 	/* Setup clocks */
1235 	sdd->clk = devm_clk_get_enabled(&pdev->dev, "spi");
1236 	if (IS_ERR(sdd->clk))
1237 		return dev_err_probe(&pdev->dev, PTR_ERR(sdd->clk),
1238 				     "Unable to acquire clock 'spi'\n");
1239 
1240 	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
1241 	sdd->src_clk = devm_clk_get_enabled(&pdev->dev, clk_name);
1242 	if (IS_ERR(sdd->src_clk))
1243 		return dev_err_probe(&pdev->dev, PTR_ERR(sdd->src_clk),
1244 				     "Unable to acquire clock '%s'\n",
1245 				     clk_name);
1246 
1247 	if (sdd->port_conf->clk_ioclk) {
1248 		sdd->ioclk = devm_clk_get_enabled(&pdev->dev, "spi_ioclk");
1249 		if (IS_ERR(sdd->ioclk))
1250 			return dev_err_probe(&pdev->dev, PTR_ERR(sdd->ioclk),
1251 					     "Unable to acquire 'ioclk'\n");
1252 	}
1253 
1254 	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1255 	pm_runtime_use_autosuspend(&pdev->dev);
1256 	pm_runtime_set_active(&pdev->dev);
1257 	pm_runtime_enable(&pdev->dev);
1258 	pm_runtime_get_sync(&pdev->dev);
1259 
1260 	/* Setup Deufult Mode */
1261 	s3c64xx_spi_hwinit(sdd);
1262 
1263 	spin_lock_init(&sdd->lock);
1264 	init_completion(&sdd->xfer_completion);
1265 
1266 	ret = devm_request_irq(&pdev->dev, irq, s3c64xx_spi_irq, 0,
1267 				"spi-s3c64xx", sdd);
1268 	if (ret != 0) {
1269 		dev_err(&pdev->dev, "Failed to request IRQ %d: %d\n",
1270 			irq, ret);
1271 		goto err_pm_put;
1272 	}
1273 
1274 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1275 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1276 	       sdd->regs + S3C64XX_SPI_INT_EN);
1277 
1278 	ret = devm_spi_register_master(&pdev->dev, master);
1279 	if (ret != 0) {
1280 		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
1281 		goto err_pm_put;
1282 	}
1283 
1284 	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",
1285 					sdd->port_id, master->num_chipselect);
1286 	dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\n",
1287 					mem_res, (FIFO_LVL_MASK(sdd) >> 1) + 1);
1288 
1289 	pm_runtime_mark_last_busy(&pdev->dev);
1290 	pm_runtime_put_autosuspend(&pdev->dev);
1291 
1292 	return 0;
1293 
1294 err_pm_put:
1295 	pm_runtime_put_noidle(&pdev->dev);
1296 	pm_runtime_disable(&pdev->dev);
1297 	pm_runtime_set_suspended(&pdev->dev);
1298 
1299 	return ret;
1300 }
1301 
1302 static void s3c64xx_spi_remove(struct platform_device *pdev)
1303 {
1304 	struct spi_master *master = platform_get_drvdata(pdev);
1305 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1306 
1307 	pm_runtime_get_sync(&pdev->dev);
1308 
1309 	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
1310 
1311 	if (!is_polling(sdd)) {
1312 		dma_release_channel(sdd->rx_dma.ch);
1313 		dma_release_channel(sdd->tx_dma.ch);
1314 	}
1315 
1316 	pm_runtime_put_noidle(&pdev->dev);
1317 	pm_runtime_disable(&pdev->dev);
1318 	pm_runtime_set_suspended(&pdev->dev);
1319 }
1320 
1321 #ifdef CONFIG_PM_SLEEP
1322 static int s3c64xx_spi_suspend(struct device *dev)
1323 {
1324 	struct spi_master *master = dev_get_drvdata(dev);
1325 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1326 
1327 	int ret = spi_master_suspend(master);
1328 	if (ret)
1329 		return ret;
1330 
1331 	ret = pm_runtime_force_suspend(dev);
1332 	if (ret < 0)
1333 		return ret;
1334 
1335 	sdd->cur_speed = 0; /* Output Clock is stopped */
1336 
1337 	return 0;
1338 }
1339 
1340 static int s3c64xx_spi_resume(struct device *dev)
1341 {
1342 	struct spi_master *master = dev_get_drvdata(dev);
1343 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1344 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1345 	int ret;
1346 
1347 	if (sci->cfg_gpio)
1348 		sci->cfg_gpio();
1349 
1350 	ret = pm_runtime_force_resume(dev);
1351 	if (ret < 0)
1352 		return ret;
1353 
1354 	return spi_master_resume(master);
1355 }
1356 #endif /* CONFIG_PM_SLEEP */
1357 
1358 #ifdef CONFIG_PM
1359 static int s3c64xx_spi_runtime_suspend(struct device *dev)
1360 {
1361 	struct spi_master *master = dev_get_drvdata(dev);
1362 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1363 
1364 	clk_disable_unprepare(sdd->clk);
1365 	clk_disable_unprepare(sdd->src_clk);
1366 	clk_disable_unprepare(sdd->ioclk);
1367 
1368 	return 0;
1369 }
1370 
1371 static int s3c64xx_spi_runtime_resume(struct device *dev)
1372 {
1373 	struct spi_master *master = dev_get_drvdata(dev);
1374 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1375 	int ret;
1376 
1377 	if (sdd->port_conf->clk_ioclk) {
1378 		ret = clk_prepare_enable(sdd->ioclk);
1379 		if (ret != 0)
1380 			return ret;
1381 	}
1382 
1383 	ret = clk_prepare_enable(sdd->src_clk);
1384 	if (ret != 0)
1385 		goto err_disable_ioclk;
1386 
1387 	ret = clk_prepare_enable(sdd->clk);
1388 	if (ret != 0)
1389 		goto err_disable_src_clk;
1390 
1391 	s3c64xx_spi_hwinit(sdd);
1392 
1393 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1394 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1395 	       sdd->regs + S3C64XX_SPI_INT_EN);
1396 
1397 	return 0;
1398 
1399 err_disable_src_clk:
1400 	clk_disable_unprepare(sdd->src_clk);
1401 err_disable_ioclk:
1402 	clk_disable_unprepare(sdd->ioclk);
1403 
1404 	return ret;
1405 }
1406 #endif /* CONFIG_PM */
1407 
1408 static const struct dev_pm_ops s3c64xx_spi_pm = {
1409 	SET_SYSTEM_SLEEP_PM_OPS(s3c64xx_spi_suspend, s3c64xx_spi_resume)
1410 	SET_RUNTIME_PM_OPS(s3c64xx_spi_runtime_suspend,
1411 			   s3c64xx_spi_runtime_resume, NULL)
1412 };
1413 
1414 static const struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
1415 	.fifo_lvl_mask	= { 0x7f },
1416 	.rx_lvl_offset	= 13,
1417 	.tx_st_done	= 21,
1418 	.clk_div	= 2,
1419 	.high_speed	= true,
1420 };
1421 
1422 static const struct s3c64xx_spi_port_config s3c6410_spi_port_config = {
1423 	.fifo_lvl_mask	= { 0x7f, 0x7F },
1424 	.rx_lvl_offset	= 13,
1425 	.tx_st_done	= 21,
1426 	.clk_div	= 2,
1427 };
1428 
1429 static const struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
1430 	.fifo_lvl_mask	= { 0x1ff, 0x7F },
1431 	.rx_lvl_offset	= 15,
1432 	.tx_st_done	= 25,
1433 	.clk_div	= 2,
1434 	.high_speed	= true,
1435 };
1436 
1437 static const struct s3c64xx_spi_port_config exynos4_spi_port_config = {
1438 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F },
1439 	.rx_lvl_offset	= 15,
1440 	.tx_st_done	= 25,
1441 	.clk_div	= 2,
1442 	.high_speed	= true,
1443 	.clk_from_cmu	= true,
1444 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1445 };
1446 
1447 static const struct s3c64xx_spi_port_config exynos7_spi_port_config = {
1448 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},
1449 	.rx_lvl_offset	= 15,
1450 	.tx_st_done	= 25,
1451 	.clk_div	= 2,
1452 	.high_speed	= true,
1453 	.clk_from_cmu	= true,
1454 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1455 };
1456 
1457 static const struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
1458 	.fifo_lvl_mask	= { 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff},
1459 	.rx_lvl_offset	= 15,
1460 	.tx_st_done	= 25,
1461 	.clk_div	= 2,
1462 	.high_speed	= true,
1463 	.clk_from_cmu	= true,
1464 	.clk_ioclk	= true,
1465 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1466 };
1467 
1468 static const struct s3c64xx_spi_port_config exynosautov9_spi_port_config = {
1469 	.fifo_lvl_mask	= { 0x1ff, 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff, 0x7f,
1470 			    0x7f, 0x7f, 0x7f, 0x7f},
1471 	.rx_lvl_offset	= 15,
1472 	.tx_st_done	= 25,
1473 	.clk_div	= 4,
1474 	.high_speed	= true,
1475 	.clk_from_cmu	= true,
1476 	.clk_ioclk	= true,
1477 	.has_loopback	= true,
1478 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1479 };
1480 
1481 static const struct s3c64xx_spi_port_config fsd_spi_port_config = {
1482 	.fifo_lvl_mask	= { 0x7f, 0x7f, 0x7f, 0x7f, 0x7f},
1483 	.rx_lvl_offset	= 15,
1484 	.tx_st_done	= 25,
1485 	.clk_div	= 2,
1486 	.high_speed	= true,
1487 	.clk_from_cmu	= true,
1488 	.clk_ioclk	= false,
1489 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1490 };
1491 
1492 static const struct platform_device_id s3c64xx_spi_driver_ids[] = {
1493 	{
1494 		.name		= "s3c2443-spi",
1495 		.driver_data	= (kernel_ulong_t)&s3c2443_spi_port_config,
1496 	}, {
1497 		.name		= "s3c6410-spi",
1498 		.driver_data	= (kernel_ulong_t)&s3c6410_spi_port_config,
1499 	},
1500 	{ },
1501 };
1502 
1503 static const struct of_device_id s3c64xx_spi_dt_match[] = {
1504 	{ .compatible = "samsung,s3c2443-spi",
1505 			.data = (void *)&s3c2443_spi_port_config,
1506 	},
1507 	{ .compatible = "samsung,s3c6410-spi",
1508 			.data = (void *)&s3c6410_spi_port_config,
1509 	},
1510 	{ .compatible = "samsung,s5pv210-spi",
1511 			.data = (void *)&s5pv210_spi_port_config,
1512 	},
1513 	{ .compatible = "samsung,exynos4210-spi",
1514 			.data = (void *)&exynos4_spi_port_config,
1515 	},
1516 	{ .compatible = "samsung,exynos7-spi",
1517 			.data = (void *)&exynos7_spi_port_config,
1518 	},
1519 	{ .compatible = "samsung,exynos5433-spi",
1520 			.data = (void *)&exynos5433_spi_port_config,
1521 	},
1522 	{ .compatible = "samsung,exynosautov9-spi",
1523 			.data = (void *)&exynosautov9_spi_port_config,
1524 	},
1525 	{ .compatible = "tesla,fsd-spi",
1526 			.data = (void *)&fsd_spi_port_config,
1527 	},
1528 	{ },
1529 };
1530 MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
1531 
1532 static struct platform_driver s3c64xx_spi_driver = {
1533 	.driver = {
1534 		.name	= "s3c64xx-spi",
1535 		.pm = &s3c64xx_spi_pm,
1536 		.of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
1537 	},
1538 	.probe = s3c64xx_spi_probe,
1539 	.remove_new = s3c64xx_spi_remove,
1540 	.id_table = s3c64xx_spi_driver_ids,
1541 };
1542 MODULE_ALIAS("platform:s3c64xx-spi");
1543 
1544 module_platform_driver(s3c64xx_spi_driver);
1545 
1546 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1547 MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1548 MODULE_LICENSE("GPL");
1549