xref: /openbmc/linux/drivers/spi/spi-s3c64xx.c (revision 9470114d)
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/bitops.h>
7 #include <linux/bits.h>
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/dmaengine.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/platform_data/spi-s3c64xx.h>
17 #include <linux/platform_device.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/spi/spi.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_TX_FIFO_LVL_SHIFT	6
81 #define S3C64XX_SPI_ST_RX_OVERRUN_ERR		(1<<5)
82 #define S3C64XX_SPI_ST_RX_UNDERRUN_ERR		(1<<4)
83 #define S3C64XX_SPI_ST_TX_OVERRUN_ERR		(1<<3)
84 #define S3C64XX_SPI_ST_TX_UNDERRUN_ERR		(1<<2)
85 #define S3C64XX_SPI_ST_RX_FIFORDY		(1<<1)
86 #define S3C64XX_SPI_ST_TX_FIFORDY		(1<<0)
87 
88 #define S3C64XX_SPI_PACKET_CNT_EN		(1<<16)
89 #define S3C64XX_SPI_PACKET_CNT_MASK		GENMASK(15, 0)
90 
91 #define S3C64XX_SPI_PND_TX_UNDERRUN_CLR		(1<<4)
92 #define S3C64XX_SPI_PND_TX_OVERRUN_CLR		(1<<3)
93 #define S3C64XX_SPI_PND_RX_UNDERRUN_CLR		(1<<2)
94 #define S3C64XX_SPI_PND_RX_OVERRUN_CLR		(1<<1)
95 #define S3C64XX_SPI_PND_TRAILING_CLR		(1<<0)
96 
97 #define S3C64XX_SPI_SWAP_RX_HALF_WORD		(1<<7)
98 #define S3C64XX_SPI_SWAP_RX_BYTE		(1<<6)
99 #define S3C64XX_SPI_SWAP_RX_BIT			(1<<5)
100 #define S3C64XX_SPI_SWAP_RX_EN			(1<<4)
101 #define S3C64XX_SPI_SWAP_TX_HALF_WORD		(1<<3)
102 #define S3C64XX_SPI_SWAP_TX_BYTE		(1<<2)
103 #define S3C64XX_SPI_SWAP_TX_BIT			(1<<1)
104 #define S3C64XX_SPI_SWAP_TX_EN			(1<<0)
105 
106 #define S3C64XX_SPI_FBCLK_MSK			(3<<0)
107 
108 #define FIFO_LVL_MASK(i) ((i)->port_conf->fifo_lvl_mask[i->port_id])
109 #define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & \
110 				(1 << (i)->port_conf->tx_st_done)) ? 1 : 0)
111 #define TX_FIFO_LVL(v, sdd)	(((v) & (sdd)->tx_fifomask) >>		\
112 				 __ffs((sdd)->tx_fifomask))
113 #define RX_FIFO_LVL(v, sdd)	(((v) & (sdd)->rx_fifomask) >>		\
114 				 __ffs((sdd)->rx_fifomask))
115 #define FIFO_DEPTH(i) ((FIFO_LVL_MASK(i) >> 1) + 1)
116 
117 #define S3C64XX_SPI_MAX_TRAILCNT	0x3ff
118 #define S3C64XX_SPI_TRAILCNT_OFF	19
119 
120 #define S3C64XX_SPI_TRAILCNT		S3C64XX_SPI_MAX_TRAILCNT
121 
122 #define S3C64XX_SPI_POLLING_SIZE	32
123 
124 #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
125 #define is_polling(x)	(x->cntrlr_info->polling)
126 
127 #define RXBUSY    (1<<2)
128 #define TXBUSY    (1<<3)
129 
130 struct s3c64xx_spi_dma_data {
131 	struct dma_chan *ch;
132 	dma_cookie_t cookie;
133 	enum dma_transfer_direction direction;
134 };
135 
136 /**
137  * struct s3c64xx_spi_port_config - SPI Controller hardware info
138  * @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
139  * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
140  * @rx_fifomask: SPI_STATUS.RX_FIFO_LVL mask. Shifted mask defining the field's
141  *               length and position.
142  * @tx_fifomask: SPI_STATUS.TX_FIFO_LVL mask. Shifted mask defining the field's
143  *               length and position.
144  * @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
145  * @clk_div: Internal clock divider
146  * @quirks: Bitmask of known quirks
147  * @high_speed: True, if the controller supports HIGH_SPEED_EN bit.
148  * @clk_from_cmu: True, if the controller does not include a clock mux and
149  *	prescaler unit.
150  * @clk_ioclk: True if clock is present on this device
151  * @has_loopback: True if loopback mode can be supported
152  *
153  * The Samsung s3c64xx SPI controller are used on various Samsung SoC's but
154  * differ in some aspects such as the size of the fifo and spi bus clock
155  * setup. Such differences are specified to the driver using this structure
156  * which is provided as driver data to the driver.
157  */
158 struct s3c64xx_spi_port_config {
159 	int	fifo_lvl_mask[MAX_SPI_PORTS];
160 	int	rx_lvl_offset;
161 	u32	rx_fifomask;
162 	u32	tx_fifomask;
163 	int	tx_st_done;
164 	int	quirks;
165 	int	clk_div;
166 	bool	high_speed;
167 	bool	clk_from_cmu;
168 	bool	clk_ioclk;
169 	bool	has_loopback;
170 };
171 
172 /**
173  * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
174  * @clk: Pointer to the spi clock.
175  * @src_clk: Pointer to the clock used to generate SPI signals.
176  * @ioclk: Pointer to the i/o clock between host and target
177  * @pdev: Pointer to device's platform device data
178  * @host: Pointer to the SPI Protocol host.
179  * @cntrlr_info: Platform specific data for the controller this driver manages.
180  * @lock: Controller specific lock.
181  * @state: Set of FLAGS to indicate status.
182  * @sfr_start: BUS address of SPI controller regs.
183  * @regs: Pointer to ioremap'ed controller registers.
184  * @xfer_completion: To indicate completion of xfer task.
185  * @cur_mode: Stores the active configuration of the controller.
186  * @cur_bpw: Stores the active bits per word settings.
187  * @cur_speed: Current clock speed
188  * @rx_dma: Local receive DMA data (e.g. chan and direction)
189  * @tx_dma: Local transmit DMA data (e.g. chan and direction)
190  * @port_conf: Local SPI port configuartion data
191  * @port_id: Port identification number
192  * @fifo_depth: depth of the FIFO.
193  * @rx_fifomask: SPI_STATUS.RX_FIFO_LVL mask. Shifted mask defining the field's
194  *               length and position.
195  * @tx_fifomask: SPI_STATUS.TX_FIFO_LVL mask. Shifted mask defining the field's
196  *               length and position.
197  */
198 struct s3c64xx_spi_driver_data {
199 	void __iomem                    *regs;
200 	struct clk                      *clk;
201 	struct clk                      *src_clk;
202 	struct clk                      *ioclk;
203 	struct platform_device          *pdev;
204 	struct spi_controller           *host;
205 	struct s3c64xx_spi_info         *cntrlr_info;
206 	spinlock_t                      lock;
207 	unsigned long                   sfr_start;
208 	struct completion               xfer_completion;
209 	unsigned                        state;
210 	unsigned                        cur_mode, cur_bpw;
211 	unsigned                        cur_speed;
212 	struct s3c64xx_spi_dma_data	rx_dma;
213 	struct s3c64xx_spi_dma_data	tx_dma;
214 	const struct s3c64xx_spi_port_config	*port_conf;
215 	unsigned int			port_id;
216 	unsigned int			fifo_depth;
217 	u32				rx_fifomask;
218 	u32				tx_fifomask;
219 };
220 
221 static void s3c64xx_flush_fifo(struct s3c64xx_spi_driver_data *sdd)
222 {
223 	void __iomem *regs = sdd->regs;
224 	unsigned long loops;
225 	u32 val;
226 
227 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
228 
229 	val = readl(regs + S3C64XX_SPI_CH_CFG);
230 	val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON);
231 	writel(val, regs + S3C64XX_SPI_CH_CFG);
232 
233 	val = readl(regs + S3C64XX_SPI_CH_CFG);
234 	val |= S3C64XX_SPI_CH_SW_RST;
235 	val &= ~S3C64XX_SPI_CH_HS_EN;
236 	writel(val, regs + S3C64XX_SPI_CH_CFG);
237 
238 	/* Flush TxFIFO*/
239 	loops = msecs_to_loops(1);
240 	do {
241 		val = readl(regs + S3C64XX_SPI_STATUS);
242 	} while (TX_FIFO_LVL(val, sdd) && loops--);
243 
244 	if (loops == 0)
245 		dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n");
246 
247 	/* Flush RxFIFO*/
248 	loops = msecs_to_loops(1);
249 	do {
250 		val = readl(regs + S3C64XX_SPI_STATUS);
251 		if (RX_FIFO_LVL(val, sdd))
252 			readl(regs + S3C64XX_SPI_RX_DATA);
253 		else
254 			break;
255 	} while (loops--);
256 
257 	if (loops == 0)
258 		dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n");
259 
260 	val = readl(regs + S3C64XX_SPI_CH_CFG);
261 	val &= ~S3C64XX_SPI_CH_SW_RST;
262 	writel(val, regs + S3C64XX_SPI_CH_CFG);
263 
264 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
265 	val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
266 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
267 }
268 
269 static void s3c64xx_spi_dmacb(void *data)
270 {
271 	struct s3c64xx_spi_driver_data *sdd;
272 	struct s3c64xx_spi_dma_data *dma = data;
273 	unsigned long flags;
274 
275 	if (dma->direction == DMA_DEV_TO_MEM)
276 		sdd = container_of(data,
277 			struct s3c64xx_spi_driver_data, rx_dma);
278 	else
279 		sdd = container_of(data,
280 			struct s3c64xx_spi_driver_data, tx_dma);
281 
282 	spin_lock_irqsave(&sdd->lock, flags);
283 
284 	if (dma->direction == DMA_DEV_TO_MEM) {
285 		sdd->state &= ~RXBUSY;
286 		if (!(sdd->state & TXBUSY))
287 			complete(&sdd->xfer_completion);
288 	} else {
289 		sdd->state &= ~TXBUSY;
290 		if (!(sdd->state & RXBUSY))
291 			complete(&sdd->xfer_completion);
292 	}
293 
294 	spin_unlock_irqrestore(&sdd->lock, flags);
295 }
296 
297 static int prepare_dma(struct s3c64xx_spi_dma_data *dma,
298 			struct sg_table *sgt)
299 {
300 	struct s3c64xx_spi_driver_data *sdd;
301 	struct dma_slave_config config;
302 	struct dma_async_tx_descriptor *desc;
303 	int ret;
304 
305 	memset(&config, 0, sizeof(config));
306 
307 	if (dma->direction == DMA_DEV_TO_MEM) {
308 		sdd = container_of((void *)dma,
309 			struct s3c64xx_spi_driver_data, rx_dma);
310 		config.direction = dma->direction;
311 		config.src_addr = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
312 		config.src_addr_width = sdd->cur_bpw / 8;
313 		config.src_maxburst = 1;
314 		dmaengine_slave_config(dma->ch, &config);
315 	} else {
316 		sdd = container_of((void *)dma,
317 			struct s3c64xx_spi_driver_data, tx_dma);
318 		config.direction = dma->direction;
319 		config.dst_addr = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
320 		config.dst_addr_width = sdd->cur_bpw / 8;
321 		config.dst_maxburst = 1;
322 		dmaengine_slave_config(dma->ch, &config);
323 	}
324 
325 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
326 				       dma->direction, DMA_PREP_INTERRUPT);
327 	if (!desc) {
328 		dev_err(&sdd->pdev->dev, "unable to prepare %s scatterlist",
329 			dma->direction == DMA_DEV_TO_MEM ? "rx" : "tx");
330 		return -ENOMEM;
331 	}
332 
333 	desc->callback = s3c64xx_spi_dmacb;
334 	desc->callback_param = dma;
335 
336 	dma->cookie = dmaengine_submit(desc);
337 	ret = dma_submit_error(dma->cookie);
338 	if (ret) {
339 		dev_err(&sdd->pdev->dev, "DMA submission failed");
340 		return -EIO;
341 	}
342 
343 	dma_async_issue_pending(dma->ch);
344 	return 0;
345 }
346 
347 static void s3c64xx_spi_set_cs(struct spi_device *spi, bool enable)
348 {
349 	struct s3c64xx_spi_driver_data *sdd =
350 					spi_controller_get_devdata(spi->controller);
351 
352 	if (sdd->cntrlr_info->no_cs)
353 		return;
354 
355 	if (enable) {
356 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO)) {
357 			writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
358 		} else {
359 			u32 ssel = readl(sdd->regs + S3C64XX_SPI_CS_REG);
360 
361 			ssel |= (S3C64XX_SPI_CS_AUTO |
362 						S3C64XX_SPI_CS_NSC_CNT_2);
363 			writel(ssel, sdd->regs + S3C64XX_SPI_CS_REG);
364 		}
365 	} else {
366 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
367 			writel(S3C64XX_SPI_CS_SIG_INACT,
368 			       sdd->regs + S3C64XX_SPI_CS_REG);
369 	}
370 }
371 
372 static int s3c64xx_spi_prepare_transfer(struct spi_controller *spi)
373 {
374 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(spi);
375 
376 	if (is_polling(sdd))
377 		return 0;
378 
379 	/* Requests DMA channels */
380 	sdd->rx_dma.ch = dma_request_chan(&sdd->pdev->dev, "rx");
381 	if (IS_ERR(sdd->rx_dma.ch)) {
382 		dev_err(&sdd->pdev->dev, "Failed to get RX DMA channel\n");
383 		sdd->rx_dma.ch = NULL;
384 		return 0;
385 	}
386 
387 	sdd->tx_dma.ch = dma_request_chan(&sdd->pdev->dev, "tx");
388 	if (IS_ERR(sdd->tx_dma.ch)) {
389 		dev_err(&sdd->pdev->dev, "Failed to get TX DMA channel\n");
390 		dma_release_channel(sdd->rx_dma.ch);
391 		sdd->tx_dma.ch = NULL;
392 		sdd->rx_dma.ch = NULL;
393 		return 0;
394 	}
395 
396 	spi->dma_rx = sdd->rx_dma.ch;
397 	spi->dma_tx = sdd->tx_dma.ch;
398 
399 	return 0;
400 }
401 
402 static int s3c64xx_spi_unprepare_transfer(struct spi_controller *spi)
403 {
404 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(spi);
405 
406 	if (is_polling(sdd))
407 		return 0;
408 
409 	/* Releases DMA channels if they are allocated */
410 	if (sdd->rx_dma.ch && sdd->tx_dma.ch) {
411 		dma_release_channel(sdd->rx_dma.ch);
412 		dma_release_channel(sdd->tx_dma.ch);
413 		sdd->rx_dma.ch = NULL;
414 		sdd->tx_dma.ch = NULL;
415 	}
416 
417 	return 0;
418 }
419 
420 static bool s3c64xx_spi_can_dma(struct spi_controller *host,
421 				struct spi_device *spi,
422 				struct spi_transfer *xfer)
423 {
424 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
425 
426 	if (sdd->rx_dma.ch && sdd->tx_dma.ch)
427 		return xfer->len >= sdd->fifo_depth;
428 
429 	return false;
430 }
431 
432 static int s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
433 				    struct spi_transfer *xfer, int dma_mode)
434 {
435 	void __iomem *regs = sdd->regs;
436 	u32 modecfg, chcfg;
437 	int ret = 0;
438 
439 	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
440 	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
441 
442 	chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
443 	chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
444 
445 	if (dma_mode) {
446 		chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
447 	} else {
448 		/* Always shift in data in FIFO, even if xfer is Tx only,
449 		 * this helps setting PCKT_CNT value for generating clocks
450 		 * as exactly needed.
451 		 */
452 		chcfg |= S3C64XX_SPI_CH_RXCH_ON;
453 		writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
454 					| S3C64XX_SPI_PACKET_CNT_EN,
455 					regs + S3C64XX_SPI_PACKET_CNT);
456 	}
457 
458 	if (xfer->tx_buf != NULL) {
459 		sdd->state |= TXBUSY;
460 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
461 		if (dma_mode) {
462 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
463 			ret = prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
464 		} else {
465 			switch (sdd->cur_bpw) {
466 			case 32:
467 				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
468 					xfer->tx_buf, xfer->len / 4);
469 				break;
470 			case 16:
471 				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
472 					xfer->tx_buf, xfer->len / 2);
473 				break;
474 			default:
475 				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
476 					xfer->tx_buf, xfer->len);
477 				break;
478 			}
479 		}
480 	}
481 
482 	if (xfer->rx_buf != NULL) {
483 		sdd->state |= RXBUSY;
484 
485 		if (sdd->port_conf->high_speed && sdd->cur_speed >= 30000000UL
486 					&& !(sdd->cur_mode & SPI_CPHA))
487 			chcfg |= S3C64XX_SPI_CH_HS_EN;
488 
489 		if (dma_mode) {
490 			modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
491 			chcfg |= S3C64XX_SPI_CH_RXCH_ON;
492 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
493 					| S3C64XX_SPI_PACKET_CNT_EN,
494 					regs + S3C64XX_SPI_PACKET_CNT);
495 			ret = prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
496 		}
497 	}
498 
499 	if (ret)
500 		return ret;
501 
502 	writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
503 	writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
504 
505 	return 0;
506 }
507 
508 static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
509 					int timeout_ms)
510 {
511 	void __iomem *regs = sdd->regs;
512 	unsigned long val = 1;
513 	u32 status;
514 	u32 max_fifo = sdd->fifo_depth;
515 
516 	if (timeout_ms)
517 		val = msecs_to_loops(timeout_ms);
518 
519 	do {
520 		status = readl(regs + S3C64XX_SPI_STATUS);
521 	} while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
522 
523 	/* return the actual received data length */
524 	return RX_FIFO_LVL(status, sdd);
525 }
526 
527 static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
528 				struct spi_transfer *xfer)
529 {
530 	void __iomem *regs = sdd->regs;
531 	unsigned long val;
532 	u32 status;
533 	int ms;
534 
535 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
536 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
537 	ms += 30;               /* some tolerance */
538 	ms = max(ms, 100);      /* minimum timeout */
539 
540 	val = msecs_to_jiffies(ms) + 10;
541 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
542 
543 	/*
544 	 * If the previous xfer was completed within timeout, then
545 	 * proceed further else return -EIO.
546 	 * DmaTx returns after simply writing data in the FIFO,
547 	 * w/o waiting for real transmission on the bus to finish.
548 	 * DmaRx returns only after Dma read data from FIFO which
549 	 * needs bus transmission to finish, so we don't worry if
550 	 * Xfer involved Rx(with or without Tx).
551 	 */
552 	if (val && !xfer->rx_buf) {
553 		val = msecs_to_loops(10);
554 		status = readl(regs + S3C64XX_SPI_STATUS);
555 		while ((TX_FIFO_LVL(status, sdd)
556 			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
557 		       && --val) {
558 			cpu_relax();
559 			status = readl(regs + S3C64XX_SPI_STATUS);
560 		}
561 
562 	}
563 
564 	/* If timed out while checking rx/tx status return error */
565 	if (!val)
566 		return -EIO;
567 
568 	return 0;
569 }
570 
571 static int s3c64xx_wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
572 				struct spi_transfer *xfer, bool use_irq)
573 {
574 	void __iomem *regs = sdd->regs;
575 	unsigned long val;
576 	u32 status;
577 	int loops;
578 	u32 cpy_len;
579 	u8 *buf;
580 	int ms;
581 	unsigned long time_us;
582 
583 	/* microsecs to xfer 'len' bytes @ 'cur_speed' */
584 	time_us = (xfer->len * 8 * 1000 * 1000) / sdd->cur_speed;
585 	ms = (time_us / 1000);
586 	ms += 10; /* some tolerance */
587 
588 	/* sleep during signal transfer time */
589 	status = readl(regs + S3C64XX_SPI_STATUS);
590 	if (RX_FIFO_LVL(status, sdd) < xfer->len)
591 		usleep_range(time_us / 2, time_us);
592 
593 	if (use_irq) {
594 		val = msecs_to_jiffies(ms);
595 		if (!wait_for_completion_timeout(&sdd->xfer_completion, val))
596 			return -EIO;
597 	}
598 
599 	val = msecs_to_loops(ms);
600 	do {
601 		status = readl(regs + S3C64XX_SPI_STATUS);
602 	} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
603 
604 	if (!val)
605 		return -EIO;
606 
607 	/* If it was only Tx */
608 	if (!xfer->rx_buf) {
609 		sdd->state &= ~TXBUSY;
610 		return 0;
611 	}
612 
613 	/*
614 	 * If the receive length is bigger than the controller fifo
615 	 * size, calculate the loops and read the fifo as many times.
616 	 * loops = length / max fifo size (calculated by using the
617 	 * fifo mask).
618 	 * For any size less than the fifo size the below code is
619 	 * executed atleast once.
620 	 */
621 	loops = xfer->len / sdd->fifo_depth;
622 	buf = xfer->rx_buf;
623 	do {
624 		/* wait for data to be received in the fifo */
625 		cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
626 						       (loops ? ms : 0));
627 
628 		switch (sdd->cur_bpw) {
629 		case 32:
630 			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
631 				     buf, cpy_len / 4);
632 			break;
633 		case 16:
634 			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
635 				     buf, cpy_len / 2);
636 			break;
637 		default:
638 			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
639 				    buf, cpy_len);
640 			break;
641 		}
642 
643 		buf = buf + cpy_len;
644 	} while (loops--);
645 	sdd->state &= ~RXBUSY;
646 
647 	return 0;
648 }
649 
650 static int s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
651 {
652 	void __iomem *regs = sdd->regs;
653 	int ret;
654 	u32 val;
655 	int div = sdd->port_conf->clk_div;
656 
657 	/* Disable Clock */
658 	if (!sdd->port_conf->clk_from_cmu) {
659 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
660 		val &= ~S3C64XX_SPI_ENCLK_ENABLE;
661 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
662 	}
663 
664 	/* Set Polarity and Phase */
665 	val = readl(regs + S3C64XX_SPI_CH_CFG);
666 	val &= ~(S3C64XX_SPI_CH_SLAVE |
667 			S3C64XX_SPI_CPOL_L |
668 			S3C64XX_SPI_CPHA_B);
669 
670 	if (sdd->cur_mode & SPI_CPOL)
671 		val |= S3C64XX_SPI_CPOL_L;
672 
673 	if (sdd->cur_mode & SPI_CPHA)
674 		val |= S3C64XX_SPI_CPHA_B;
675 
676 	writel(val, regs + S3C64XX_SPI_CH_CFG);
677 
678 	/* Set Channel & DMA Mode */
679 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
680 	val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
681 			| S3C64XX_SPI_MODE_CH_TSZ_MASK);
682 
683 	switch (sdd->cur_bpw) {
684 	case 32:
685 		val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
686 		val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;
687 		break;
688 	case 16:
689 		val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
690 		val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;
691 		break;
692 	default:
693 		val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
694 		val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;
695 		break;
696 	}
697 
698 	if ((sdd->cur_mode & SPI_LOOP) && sdd->port_conf->has_loopback)
699 		val |= S3C64XX_SPI_MODE_SELF_LOOPBACK;
700 	else
701 		val &= ~S3C64XX_SPI_MODE_SELF_LOOPBACK;
702 
703 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
704 
705 	if (sdd->port_conf->clk_from_cmu) {
706 		ret = clk_set_rate(sdd->src_clk, sdd->cur_speed * div);
707 		if (ret)
708 			return ret;
709 		sdd->cur_speed = clk_get_rate(sdd->src_clk) / div;
710 	} else {
711 		/* Configure Clock */
712 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
713 		val &= ~S3C64XX_SPI_PSR_MASK;
714 		val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / div - 1)
715 				& S3C64XX_SPI_PSR_MASK);
716 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
717 
718 		/* Enable Clock */
719 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
720 		val |= S3C64XX_SPI_ENCLK_ENABLE;
721 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
722 	}
723 
724 	return 0;
725 }
726 
727 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
728 
729 static int s3c64xx_spi_prepare_message(struct spi_controller *host,
730 				       struct spi_message *msg)
731 {
732 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
733 	struct spi_device *spi = msg->spi;
734 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
735 
736 	/* Configure feedback delay */
737 	if (!cs)
738 		/* No delay if not defined */
739 		writel(0, sdd->regs + S3C64XX_SPI_FB_CLK);
740 	else
741 		writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
742 
743 	return 0;
744 }
745 
746 static size_t s3c64xx_spi_max_transfer_size(struct spi_device *spi)
747 {
748 	struct spi_controller *ctlr = spi->controller;
749 
750 	return ctlr->can_dma ? S3C64XX_SPI_PACKET_CNT_MASK : SIZE_MAX;
751 }
752 
753 static int s3c64xx_spi_transfer_one(struct spi_controller *host,
754 				    struct spi_device *spi,
755 				    struct spi_transfer *xfer)
756 {
757 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
758 	const unsigned int fifo_len = sdd->fifo_depth;
759 	const void *tx_buf = NULL;
760 	void *rx_buf = NULL;
761 	int target_len = 0, origin_len = 0;
762 	int use_dma = 0;
763 	bool use_irq = false;
764 	int status;
765 	u32 speed;
766 	u8 bpw;
767 	unsigned long flags;
768 	u32 rdy_lv;
769 	u32 val;
770 
771 	reinit_completion(&sdd->xfer_completion);
772 
773 	/* Only BPW and Speed may change across transfers */
774 	bpw = xfer->bits_per_word;
775 	speed = xfer->speed_hz;
776 
777 	if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
778 		sdd->cur_bpw = bpw;
779 		sdd->cur_speed = speed;
780 		sdd->cur_mode = spi->mode;
781 		status = s3c64xx_spi_config(sdd);
782 		if (status)
783 			return status;
784 	}
785 
786 	if (!is_polling(sdd) && xfer->len >= fifo_len &&
787 	    sdd->rx_dma.ch && sdd->tx_dma.ch) {
788 		use_dma = 1;
789 	} else if (xfer->len >= fifo_len) {
790 		tx_buf = xfer->tx_buf;
791 		rx_buf = xfer->rx_buf;
792 		origin_len = xfer->len;
793 		target_len = xfer->len;
794 		xfer->len = fifo_len - 1;
795 	}
796 
797 	do {
798 		/* transfer size is greater than 32, change to IRQ mode */
799 		if (!use_dma && xfer->len > S3C64XX_SPI_POLLING_SIZE)
800 			use_irq = true;
801 
802 		if (use_irq) {
803 			reinit_completion(&sdd->xfer_completion);
804 
805 			rdy_lv = xfer->len;
806 			/* Setup RDY_FIFO trigger Level
807 			 * RDY_LVL =
808 			 * fifo_lvl up to 64 byte -> N bytes
809 			 *               128 byte -> RDY_LVL * 2 bytes
810 			 *               256 byte -> RDY_LVL * 4 bytes
811 			 */
812 			if (fifo_len == 128)
813 				rdy_lv /= 2;
814 			else if (fifo_len == 256)
815 				rdy_lv /= 4;
816 
817 			val = readl(sdd->regs + S3C64XX_SPI_MODE_CFG);
818 			val &= ~S3C64XX_SPI_MODE_RX_RDY_LVL;
819 			val |= (rdy_lv << S3C64XX_SPI_MODE_RX_RDY_LVL_SHIFT);
820 			writel(val, sdd->regs + S3C64XX_SPI_MODE_CFG);
821 
822 			/* Enable FIFO_RDY_EN IRQ */
823 			val = readl(sdd->regs + S3C64XX_SPI_INT_EN);
824 			writel((val | S3C64XX_SPI_INT_RX_FIFORDY_EN),
825 					sdd->regs + S3C64XX_SPI_INT_EN);
826 
827 		}
828 
829 		spin_lock_irqsave(&sdd->lock, flags);
830 
831 		/* Pending only which is to be done */
832 		sdd->state &= ~RXBUSY;
833 		sdd->state &= ~TXBUSY;
834 
835 		/* Start the signals */
836 		s3c64xx_spi_set_cs(spi, true);
837 
838 		status = s3c64xx_enable_datapath(sdd, xfer, use_dma);
839 
840 		spin_unlock_irqrestore(&sdd->lock, flags);
841 
842 		if (status) {
843 			dev_err(&spi->dev, "failed to enable data path for transfer: %d\n", status);
844 			break;
845 		}
846 
847 		if (use_dma)
848 			status = s3c64xx_wait_for_dma(sdd, xfer);
849 		else
850 			status = s3c64xx_wait_for_pio(sdd, xfer, use_irq);
851 
852 		if (status) {
853 			dev_err(&spi->dev,
854 				"I/O Error: rx-%d tx-%d rx-%c tx-%c len-%d dma-%d res-(%d)\n",
855 				xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
856 				(sdd->state & RXBUSY) ? 'f' : 'p',
857 				(sdd->state & TXBUSY) ? 'f' : 'p',
858 				xfer->len, use_dma ? 1 : 0, status);
859 
860 			if (use_dma) {
861 				struct dma_tx_state s;
862 
863 				if (xfer->tx_buf && (sdd->state & TXBUSY)) {
864 					dmaengine_pause(sdd->tx_dma.ch);
865 					dmaengine_tx_status(sdd->tx_dma.ch, sdd->tx_dma.cookie, &s);
866 					dmaengine_terminate_all(sdd->tx_dma.ch);
867 					dev_err(&spi->dev, "TX residue: %d\n", s.residue);
868 
869 				}
870 				if (xfer->rx_buf && (sdd->state & RXBUSY)) {
871 					dmaengine_pause(sdd->rx_dma.ch);
872 					dmaengine_tx_status(sdd->rx_dma.ch, sdd->rx_dma.cookie, &s);
873 					dmaengine_terminate_all(sdd->rx_dma.ch);
874 					dev_err(&spi->dev, "RX residue: %d\n", s.residue);
875 				}
876 			}
877 		} else {
878 			s3c64xx_flush_fifo(sdd);
879 		}
880 		if (target_len > 0) {
881 			target_len -= xfer->len;
882 
883 			if (xfer->tx_buf)
884 				xfer->tx_buf += xfer->len;
885 
886 			if (xfer->rx_buf)
887 				xfer->rx_buf += xfer->len;
888 
889 			if (target_len >= fifo_len)
890 				xfer->len = fifo_len - 1;
891 			else
892 				xfer->len = target_len;
893 		}
894 	} while (target_len > 0);
895 
896 	if (origin_len) {
897 		/* Restore original xfer buffers and length */
898 		xfer->tx_buf = tx_buf;
899 		xfer->rx_buf = rx_buf;
900 		xfer->len = origin_len;
901 	}
902 
903 	return status;
904 }
905 
906 static struct s3c64xx_spi_csinfo *s3c64xx_get_target_ctrldata(
907 				struct spi_device *spi)
908 {
909 	struct s3c64xx_spi_csinfo *cs;
910 	struct device_node *target_np, *data_np = NULL;
911 	u32 fb_delay = 0;
912 
913 	target_np = spi->dev.of_node;
914 	if (!target_np) {
915 		dev_err(&spi->dev, "device node not found\n");
916 		return ERR_PTR(-EINVAL);
917 	}
918 
919 	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
920 	if (!cs)
921 		return ERR_PTR(-ENOMEM);
922 
923 	data_np = of_get_child_by_name(target_np, "controller-data");
924 	if (!data_np) {
925 		dev_info(&spi->dev, "feedback delay set to default (0)\n");
926 		return cs;
927 	}
928 
929 	of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
930 	cs->fb_delay = fb_delay;
931 	of_node_put(data_np);
932 	return cs;
933 }
934 
935 /*
936  * Here we only check the validity of requested configuration
937  * and save the configuration in a local data-structure.
938  * The controller is actually configured only just before we
939  * get a message to transfer.
940  */
941 static int s3c64xx_spi_setup(struct spi_device *spi)
942 {
943 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
944 	struct s3c64xx_spi_driver_data *sdd;
945 	int err;
946 	int div;
947 
948 	sdd = spi_controller_get_devdata(spi->controller);
949 	if (spi->dev.of_node) {
950 		cs = s3c64xx_get_target_ctrldata(spi);
951 		spi->controller_data = cs;
952 	}
953 
954 	/* NULL is fine, we just avoid using the FB delay (=0) */
955 	if (IS_ERR(cs)) {
956 		dev_err(&spi->dev, "No CS for SPI(%d)\n", spi_get_chipselect(spi, 0));
957 		return -ENODEV;
958 	}
959 
960 	if (!spi_get_ctldata(spi))
961 		spi_set_ctldata(spi, cs);
962 
963 	pm_runtime_get_sync(&sdd->pdev->dev);
964 
965 	div = sdd->port_conf->clk_div;
966 
967 	/* Check if we can provide the requested rate */
968 	if (!sdd->port_conf->clk_from_cmu) {
969 		u32 psr, speed;
970 
971 		/* Max possible */
972 		speed = clk_get_rate(sdd->src_clk) / div / (0 + 1);
973 
974 		if (spi->max_speed_hz > speed)
975 			spi->max_speed_hz = speed;
976 
977 		psr = clk_get_rate(sdd->src_clk) / div / spi->max_speed_hz - 1;
978 		psr &= S3C64XX_SPI_PSR_MASK;
979 		if (psr == S3C64XX_SPI_PSR_MASK)
980 			psr--;
981 
982 		speed = clk_get_rate(sdd->src_clk) / div / (psr + 1);
983 		if (spi->max_speed_hz < speed) {
984 			if (psr+1 < S3C64XX_SPI_PSR_MASK) {
985 				psr++;
986 			} else {
987 				err = -EINVAL;
988 				goto setup_exit;
989 			}
990 		}
991 
992 		speed = clk_get_rate(sdd->src_clk) / div / (psr + 1);
993 		if (spi->max_speed_hz >= speed) {
994 			spi->max_speed_hz = speed;
995 		} else {
996 			dev_err(&spi->dev, "Can't set %dHz transfer speed\n",
997 				spi->max_speed_hz);
998 			err = -EINVAL;
999 			goto setup_exit;
1000 		}
1001 	}
1002 
1003 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
1004 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
1005 	s3c64xx_spi_set_cs(spi, false);
1006 
1007 	return 0;
1008 
1009 setup_exit:
1010 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
1011 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
1012 	/* setup() returns with device de-selected */
1013 	s3c64xx_spi_set_cs(spi, false);
1014 
1015 	spi_set_ctldata(spi, NULL);
1016 
1017 	/* This was dynamically allocated on the DT path */
1018 	if (spi->dev.of_node)
1019 		kfree(cs);
1020 
1021 	return err;
1022 }
1023 
1024 static void s3c64xx_spi_cleanup(struct spi_device *spi)
1025 {
1026 	struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
1027 
1028 	/* This was dynamically allocated on the DT path */
1029 	if (spi->dev.of_node)
1030 		kfree(cs);
1031 
1032 	spi_set_ctldata(spi, NULL);
1033 }
1034 
1035 static irqreturn_t s3c64xx_spi_irq(int irq, void *data)
1036 {
1037 	struct s3c64xx_spi_driver_data *sdd = data;
1038 	struct spi_controller *spi = sdd->host;
1039 	unsigned int val, clr = 0;
1040 
1041 	val = readl(sdd->regs + S3C64XX_SPI_STATUS);
1042 
1043 	if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) {
1044 		clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR;
1045 		dev_err(&spi->dev, "RX overrun\n");
1046 	}
1047 	if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) {
1048 		clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR;
1049 		dev_err(&spi->dev, "RX underrun\n");
1050 	}
1051 	if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) {
1052 		clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR;
1053 		dev_err(&spi->dev, "TX overrun\n");
1054 	}
1055 	if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) {
1056 		clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
1057 		dev_err(&spi->dev, "TX underrun\n");
1058 	}
1059 
1060 	if (val & S3C64XX_SPI_ST_RX_FIFORDY) {
1061 		complete(&sdd->xfer_completion);
1062 		/* No pending clear irq, turn-off INT_EN_RX_FIFO_RDY */
1063 		val = readl(sdd->regs + S3C64XX_SPI_INT_EN);
1064 		writel((val & ~S3C64XX_SPI_INT_RX_FIFORDY_EN),
1065 				sdd->regs + S3C64XX_SPI_INT_EN);
1066 	}
1067 
1068 	/* Clear the pending irq by setting and then clearing it */
1069 	writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR);
1070 	writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR);
1071 
1072 	return IRQ_HANDLED;
1073 }
1074 
1075 static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd)
1076 {
1077 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1078 	void __iomem *regs = sdd->regs;
1079 	unsigned int val;
1080 
1081 	sdd->cur_speed = 0;
1082 
1083 	if (sci->no_cs)
1084 		writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
1085 	else if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
1086 		writel(S3C64XX_SPI_CS_SIG_INACT, sdd->regs + S3C64XX_SPI_CS_REG);
1087 
1088 	/* Disable Interrupts - we use Polling if not DMA mode */
1089 	writel(0, regs + S3C64XX_SPI_INT_EN);
1090 
1091 	if (!sdd->port_conf->clk_from_cmu)
1092 		writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
1093 				regs + S3C64XX_SPI_CLK_CFG);
1094 	writel(0, regs + S3C64XX_SPI_MODE_CFG);
1095 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
1096 
1097 	/* Clear any irq pending bits, should set and clear the bits */
1098 	val = S3C64XX_SPI_PND_RX_OVERRUN_CLR |
1099 		S3C64XX_SPI_PND_RX_UNDERRUN_CLR |
1100 		S3C64XX_SPI_PND_TX_OVERRUN_CLR |
1101 		S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
1102 	writel(val, regs + S3C64XX_SPI_PENDING_CLR);
1103 	writel(0, regs + S3C64XX_SPI_PENDING_CLR);
1104 
1105 	writel(0, regs + S3C64XX_SPI_SWAP_CFG);
1106 
1107 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
1108 	val &= ~S3C64XX_SPI_MODE_4BURST;
1109 	val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
1110 	val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
1111 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
1112 
1113 	s3c64xx_flush_fifo(sdd);
1114 }
1115 
1116 #ifdef CONFIG_OF
1117 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1118 {
1119 	struct s3c64xx_spi_info *sci;
1120 	u32 temp;
1121 
1122 	sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
1123 	if (!sci)
1124 		return ERR_PTR(-ENOMEM);
1125 
1126 	if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
1127 		dev_warn(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
1128 		sci->src_clk_nr = 0;
1129 	} else {
1130 		sci->src_clk_nr = temp;
1131 	}
1132 
1133 	if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
1134 		dev_warn(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
1135 		sci->num_cs = 1;
1136 	} else {
1137 		sci->num_cs = temp;
1138 	}
1139 
1140 	sci->no_cs = of_property_read_bool(dev->of_node, "no-cs-readback");
1141 	sci->polling = !of_property_present(dev->of_node, "dmas");
1142 
1143 	return sci;
1144 }
1145 #else
1146 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1147 {
1148 	return dev_get_platdata(dev);
1149 }
1150 #endif
1151 
1152 static inline const struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
1153 						struct platform_device *pdev)
1154 {
1155 #ifdef CONFIG_OF
1156 	if (pdev->dev.of_node)
1157 		return of_device_get_match_data(&pdev->dev);
1158 #endif
1159 	return (const struct s3c64xx_spi_port_config *)platform_get_device_id(pdev)->driver_data;
1160 }
1161 
1162 static void s3c64xx_spi_set_fifomask(struct s3c64xx_spi_driver_data *sdd)
1163 {
1164 	const struct s3c64xx_spi_port_config *port_conf = sdd->port_conf;
1165 
1166 	if (port_conf->rx_fifomask)
1167 		sdd->rx_fifomask = port_conf->rx_fifomask;
1168 	else
1169 		sdd->rx_fifomask = FIFO_LVL_MASK(sdd) <<
1170 			port_conf->rx_lvl_offset;
1171 
1172 	if (port_conf->tx_fifomask)
1173 		sdd->tx_fifomask = port_conf->tx_fifomask;
1174 	else
1175 		sdd->tx_fifomask = FIFO_LVL_MASK(sdd) <<
1176 			S3C64XX_SPI_ST_TX_FIFO_LVL_SHIFT;
1177 }
1178 
1179 static int s3c64xx_spi_probe(struct platform_device *pdev)
1180 {
1181 	struct resource	*mem_res;
1182 	struct s3c64xx_spi_driver_data *sdd;
1183 	struct s3c64xx_spi_info *sci = dev_get_platdata(&pdev->dev);
1184 	struct spi_controller *host;
1185 	int ret, irq;
1186 	char clk_name[16];
1187 
1188 	if (!sci && pdev->dev.of_node) {
1189 		sci = s3c64xx_spi_parse_dt(&pdev->dev);
1190 		if (IS_ERR(sci))
1191 			return PTR_ERR(sci);
1192 	}
1193 
1194 	if (!sci)
1195 		return dev_err_probe(&pdev->dev, -ENODEV,
1196 				     "Platform_data missing!\n");
1197 
1198 	irq = platform_get_irq(pdev, 0);
1199 	if (irq < 0)
1200 		return irq;
1201 
1202 	host = devm_spi_alloc_host(&pdev->dev, sizeof(*sdd));
1203 	if (!host)
1204 		return dev_err_probe(&pdev->dev, -ENOMEM,
1205 				     "Unable to allocate SPI Host\n");
1206 
1207 	platform_set_drvdata(pdev, host);
1208 
1209 	sdd = spi_controller_get_devdata(host);
1210 	sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
1211 	sdd->host = host;
1212 	sdd->cntrlr_info = sci;
1213 	sdd->pdev = pdev;
1214 	if (pdev->dev.of_node) {
1215 		ret = of_alias_get_id(pdev->dev.of_node, "spi");
1216 		if (ret < 0)
1217 			return dev_err_probe(&pdev->dev, ret,
1218 					     "Failed to get alias id\n");
1219 		sdd->port_id = ret;
1220 	} else {
1221 		sdd->port_id = pdev->id;
1222 	}
1223 
1224 	sdd->fifo_depth = FIFO_DEPTH(sdd);
1225 
1226 	s3c64xx_spi_set_fifomask(sdd);
1227 
1228 	sdd->cur_bpw = 8;
1229 
1230 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
1231 	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
1232 
1233 	host->dev.of_node = pdev->dev.of_node;
1234 	host->bus_num = sdd->port_id;
1235 	host->setup = s3c64xx_spi_setup;
1236 	host->cleanup = s3c64xx_spi_cleanup;
1237 	host->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
1238 	host->unprepare_transfer_hardware = s3c64xx_spi_unprepare_transfer;
1239 	host->prepare_message = s3c64xx_spi_prepare_message;
1240 	host->transfer_one = s3c64xx_spi_transfer_one;
1241 	host->max_transfer_size = s3c64xx_spi_max_transfer_size;
1242 	host->num_chipselect = sci->num_cs;
1243 	host->use_gpio_descriptors = true;
1244 	host->dma_alignment = 8;
1245 	host->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
1246 				   SPI_BPW_MASK(8);
1247 	/* the spi->mode bits understood by this driver: */
1248 	host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1249 	if (sdd->port_conf->has_loopback)
1250 		host->mode_bits |= SPI_LOOP;
1251 	host->auto_runtime_pm = true;
1252 	if (!is_polling(sdd))
1253 		host->can_dma = s3c64xx_spi_can_dma;
1254 
1255 	sdd->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &mem_res);
1256 	if (IS_ERR(sdd->regs))
1257 		return PTR_ERR(sdd->regs);
1258 	sdd->sfr_start = mem_res->start;
1259 
1260 	if (sci->cfg_gpio && sci->cfg_gpio())
1261 		return dev_err_probe(&pdev->dev, -EBUSY,
1262 				     "Unable to config gpio\n");
1263 
1264 	/* Setup clocks */
1265 	sdd->clk = devm_clk_get_enabled(&pdev->dev, "spi");
1266 	if (IS_ERR(sdd->clk))
1267 		return dev_err_probe(&pdev->dev, PTR_ERR(sdd->clk),
1268 				     "Unable to acquire clock 'spi'\n");
1269 
1270 	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
1271 	sdd->src_clk = devm_clk_get_enabled(&pdev->dev, clk_name);
1272 	if (IS_ERR(sdd->src_clk))
1273 		return dev_err_probe(&pdev->dev, PTR_ERR(sdd->src_clk),
1274 				     "Unable to acquire clock '%s'\n",
1275 				     clk_name);
1276 
1277 	if (sdd->port_conf->clk_ioclk) {
1278 		sdd->ioclk = devm_clk_get_enabled(&pdev->dev, "spi_ioclk");
1279 		if (IS_ERR(sdd->ioclk))
1280 			return dev_err_probe(&pdev->dev, PTR_ERR(sdd->ioclk),
1281 					     "Unable to acquire 'ioclk'\n");
1282 	}
1283 
1284 	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1285 	pm_runtime_use_autosuspend(&pdev->dev);
1286 	pm_runtime_set_active(&pdev->dev);
1287 	pm_runtime_enable(&pdev->dev);
1288 	pm_runtime_get_sync(&pdev->dev);
1289 
1290 	/* Setup Deufult Mode */
1291 	s3c64xx_spi_hwinit(sdd);
1292 
1293 	spin_lock_init(&sdd->lock);
1294 	init_completion(&sdd->xfer_completion);
1295 
1296 	ret = devm_request_irq(&pdev->dev, irq, s3c64xx_spi_irq, 0,
1297 				"spi-s3c64xx", sdd);
1298 	if (ret != 0) {
1299 		dev_err(&pdev->dev, "Failed to request IRQ %d: %d\n",
1300 			irq, ret);
1301 		goto err_pm_put;
1302 	}
1303 
1304 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1305 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1306 	       sdd->regs + S3C64XX_SPI_INT_EN);
1307 
1308 	ret = devm_spi_register_controller(&pdev->dev, host);
1309 	if (ret != 0) {
1310 		dev_err(&pdev->dev, "cannot register SPI host: %d\n", ret);
1311 		goto err_pm_put;
1312 	}
1313 
1314 	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Targets attached\n",
1315 					sdd->port_id, host->num_chipselect);
1316 	dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\n",
1317 		mem_res, sdd->fifo_depth);
1318 
1319 	pm_runtime_mark_last_busy(&pdev->dev);
1320 	pm_runtime_put_autosuspend(&pdev->dev);
1321 
1322 	return 0;
1323 
1324 err_pm_put:
1325 	pm_runtime_put_noidle(&pdev->dev);
1326 	pm_runtime_disable(&pdev->dev);
1327 	pm_runtime_set_suspended(&pdev->dev);
1328 
1329 	return ret;
1330 }
1331 
1332 static void s3c64xx_spi_remove(struct platform_device *pdev)
1333 {
1334 	struct spi_controller *host = platform_get_drvdata(pdev);
1335 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
1336 
1337 	pm_runtime_get_sync(&pdev->dev);
1338 
1339 	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
1340 
1341 	if (!is_polling(sdd)) {
1342 		dma_release_channel(sdd->rx_dma.ch);
1343 		dma_release_channel(sdd->tx_dma.ch);
1344 	}
1345 
1346 	pm_runtime_put_noidle(&pdev->dev);
1347 	pm_runtime_disable(&pdev->dev);
1348 	pm_runtime_set_suspended(&pdev->dev);
1349 }
1350 
1351 #ifdef CONFIG_PM_SLEEP
1352 static int s3c64xx_spi_suspend(struct device *dev)
1353 {
1354 	struct spi_controller *host = dev_get_drvdata(dev);
1355 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
1356 
1357 	int ret = spi_controller_suspend(host);
1358 	if (ret)
1359 		return ret;
1360 
1361 	ret = pm_runtime_force_suspend(dev);
1362 	if (ret < 0)
1363 		return ret;
1364 
1365 	sdd->cur_speed = 0; /* Output Clock is stopped */
1366 
1367 	return 0;
1368 }
1369 
1370 static int s3c64xx_spi_resume(struct device *dev)
1371 {
1372 	struct spi_controller *host = dev_get_drvdata(dev);
1373 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
1374 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1375 	int ret;
1376 
1377 	if (sci->cfg_gpio)
1378 		sci->cfg_gpio();
1379 
1380 	ret = pm_runtime_force_resume(dev);
1381 	if (ret < 0)
1382 		return ret;
1383 
1384 	return spi_controller_resume(host);
1385 }
1386 #endif /* CONFIG_PM_SLEEP */
1387 
1388 #ifdef CONFIG_PM
1389 static int s3c64xx_spi_runtime_suspend(struct device *dev)
1390 {
1391 	struct spi_controller *host = dev_get_drvdata(dev);
1392 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
1393 
1394 	clk_disable_unprepare(sdd->clk);
1395 	clk_disable_unprepare(sdd->src_clk);
1396 	clk_disable_unprepare(sdd->ioclk);
1397 
1398 	return 0;
1399 }
1400 
1401 static int s3c64xx_spi_runtime_resume(struct device *dev)
1402 {
1403 	struct spi_controller *host = dev_get_drvdata(dev);
1404 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
1405 	int ret;
1406 
1407 	if (sdd->port_conf->clk_ioclk) {
1408 		ret = clk_prepare_enable(sdd->ioclk);
1409 		if (ret != 0)
1410 			return ret;
1411 	}
1412 
1413 	ret = clk_prepare_enable(sdd->src_clk);
1414 	if (ret != 0)
1415 		goto err_disable_ioclk;
1416 
1417 	ret = clk_prepare_enable(sdd->clk);
1418 	if (ret != 0)
1419 		goto err_disable_src_clk;
1420 
1421 	s3c64xx_spi_hwinit(sdd);
1422 
1423 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1424 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1425 	       sdd->regs + S3C64XX_SPI_INT_EN);
1426 
1427 	return 0;
1428 
1429 err_disable_src_clk:
1430 	clk_disable_unprepare(sdd->src_clk);
1431 err_disable_ioclk:
1432 	clk_disable_unprepare(sdd->ioclk);
1433 
1434 	return ret;
1435 }
1436 #endif /* CONFIG_PM */
1437 
1438 static const struct dev_pm_ops s3c64xx_spi_pm = {
1439 	SET_SYSTEM_SLEEP_PM_OPS(s3c64xx_spi_suspend, s3c64xx_spi_resume)
1440 	SET_RUNTIME_PM_OPS(s3c64xx_spi_runtime_suspend,
1441 			   s3c64xx_spi_runtime_resume, NULL)
1442 };
1443 
1444 static const struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
1445 	.fifo_lvl_mask	= { 0x7f },
1446 	.rx_lvl_offset	= 13,
1447 	.tx_st_done	= 21,
1448 	.clk_div	= 2,
1449 	.high_speed	= true,
1450 };
1451 
1452 static const struct s3c64xx_spi_port_config s3c6410_spi_port_config = {
1453 	.fifo_lvl_mask	= { 0x7f, 0x7F },
1454 	.rx_lvl_offset	= 13,
1455 	.tx_st_done	= 21,
1456 	.clk_div	= 2,
1457 };
1458 
1459 static const struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
1460 	.fifo_lvl_mask	= { 0x1ff, 0x7F },
1461 	.rx_lvl_offset	= 15,
1462 	.tx_st_done	= 25,
1463 	.clk_div	= 2,
1464 	.high_speed	= true,
1465 };
1466 
1467 static const struct s3c64xx_spi_port_config exynos4_spi_port_config = {
1468 	.fifo_lvl_mask	= { 0x1ff, 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 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1475 };
1476 
1477 static const struct s3c64xx_spi_port_config exynos7_spi_port_config = {
1478 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},
1479 	.rx_lvl_offset	= 15,
1480 	.tx_st_done	= 25,
1481 	.clk_div	= 2,
1482 	.high_speed	= true,
1483 	.clk_from_cmu	= true,
1484 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1485 };
1486 
1487 static const struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
1488 	.fifo_lvl_mask	= { 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff},
1489 	.rx_lvl_offset	= 15,
1490 	.tx_st_done	= 25,
1491 	.clk_div	= 2,
1492 	.high_speed	= true,
1493 	.clk_from_cmu	= true,
1494 	.clk_ioclk	= true,
1495 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1496 };
1497 
1498 static const struct s3c64xx_spi_port_config exynosautov9_spi_port_config = {
1499 	.fifo_lvl_mask	= { 0x1ff, 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff, 0x7f,
1500 			    0x7f, 0x7f, 0x7f, 0x7f},
1501 	.rx_lvl_offset	= 15,
1502 	.tx_st_done	= 25,
1503 	.clk_div	= 4,
1504 	.high_speed	= true,
1505 	.clk_from_cmu	= true,
1506 	.clk_ioclk	= true,
1507 	.has_loopback	= true,
1508 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1509 };
1510 
1511 static const struct s3c64xx_spi_port_config fsd_spi_port_config = {
1512 	.fifo_lvl_mask	= { 0x7f, 0x7f, 0x7f, 0x7f, 0x7f},
1513 	.rx_lvl_offset	= 15,
1514 	.tx_st_done	= 25,
1515 	.clk_div	= 2,
1516 	.high_speed	= true,
1517 	.clk_from_cmu	= true,
1518 	.clk_ioclk	= false,
1519 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1520 };
1521 
1522 static const struct platform_device_id s3c64xx_spi_driver_ids[] = {
1523 	{
1524 		.name		= "s3c2443-spi",
1525 		.driver_data	= (kernel_ulong_t)&s3c2443_spi_port_config,
1526 	}, {
1527 		.name		= "s3c6410-spi",
1528 		.driver_data	= (kernel_ulong_t)&s3c6410_spi_port_config,
1529 	},
1530 	{ },
1531 };
1532 
1533 static const struct of_device_id s3c64xx_spi_dt_match[] = {
1534 	{ .compatible = "samsung,s3c2443-spi",
1535 			.data = (void *)&s3c2443_spi_port_config,
1536 	},
1537 	{ .compatible = "samsung,s3c6410-spi",
1538 			.data = (void *)&s3c6410_spi_port_config,
1539 	},
1540 	{ .compatible = "samsung,s5pv210-spi",
1541 			.data = (void *)&s5pv210_spi_port_config,
1542 	},
1543 	{ .compatible = "samsung,exynos4210-spi",
1544 			.data = (void *)&exynos4_spi_port_config,
1545 	},
1546 	{ .compatible = "samsung,exynos7-spi",
1547 			.data = (void *)&exynos7_spi_port_config,
1548 	},
1549 	{ .compatible = "samsung,exynos5433-spi",
1550 			.data = (void *)&exynos5433_spi_port_config,
1551 	},
1552 	{ .compatible = "samsung,exynosautov9-spi",
1553 			.data = (void *)&exynosautov9_spi_port_config,
1554 	},
1555 	{ .compatible = "tesla,fsd-spi",
1556 			.data = (void *)&fsd_spi_port_config,
1557 	},
1558 	{ },
1559 };
1560 MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
1561 
1562 static struct platform_driver s3c64xx_spi_driver = {
1563 	.driver = {
1564 		.name	= "s3c64xx-spi",
1565 		.pm = &s3c64xx_spi_pm,
1566 		.of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
1567 	},
1568 	.probe = s3c64xx_spi_probe,
1569 	.remove_new = s3c64xx_spi_remove,
1570 	.id_table = s3c64xx_spi_driver_ids,
1571 };
1572 MODULE_ALIAS("platform:s3c64xx-spi");
1573 
1574 module_platform_driver(s3c64xx_spi_driver);
1575 
1576 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1577 MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1578 MODULE_LICENSE("GPL");
1579