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spi/s3c64xx: Differentiate ip and rate clock
[deliverable/linux.git] / drivers / spi / spi_s3c64xx.c
CommitLineData
230d42d4
JB		 1/* linux/drivers/spi/spi_s3c64xx.c
2 *
3 * Copyright (C) 2009 Samsung Electronics Ltd.
4 * Jaswinder Singh <jassi.brar@samsung.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21#include <linux/init.h>
22#include <linux/module.h>
23#include <linux/workqueue.h>
24#include <linux/delay.h>
25#include <linux/clk.h>
26#include <linux/dma-mapping.h>
27#include <linux/platform_device.h>
28#include <linux/spi/spi.h>
29
30#include <mach/dma.h>
31#include <plat/spi.h>
32
33/* Registers and bit-fields */
34
35#define S3C64XX_SPI_CH_CFG 0x00
36#define S3C64XX_SPI_CLK_CFG 0x04
37#define S3C64XX_SPI_MODE_CFG 0x08
38#define S3C64XX_SPI_SLAVE_SEL 0x0C
39#define S3C64XX_SPI_INT_EN 0x10
40#define S3C64XX_SPI_STATUS 0x14
41#define S3C64XX_SPI_TX_DATA 0x18
42#define S3C64XX_SPI_RX_DATA 0x1C
43#define S3C64XX_SPI_PACKET_CNT 0x20
44#define S3C64XX_SPI_PENDING_CLR 0x24
45#define S3C64XX_SPI_SWAP_CFG 0x28
46#define S3C64XX_SPI_FB_CLK 0x2C
47
48#define S3C64XX_SPI_CH_HS_EN (1<<6) /* High Speed Enable */
49#define S3C64XX_SPI_CH_SW_RST (1<<5)
50#define S3C64XX_SPI_CH_SLAVE (1<<4)
51#define S3C64XX_SPI_CPOL_L (1<<3)
52#define S3C64XX_SPI_CPHA_B (1<<2)
53#define S3C64XX_SPI_CH_RXCH_ON (1<<1)
54#define S3C64XX_SPI_CH_TXCH_ON (1<<0)
55
56#define S3C64XX_SPI_CLKSEL_SRCMSK (3<<9)
57#define S3C64XX_SPI_CLKSEL_SRCSHFT 9
58#define S3C64XX_SPI_ENCLK_ENABLE (1<<8)
59#define S3C64XX_SPI_PSR_MASK 0xff
60
61#define S3C64XX_SPI_MODE_CH_TSZ_BYTE (0<<29)
62#define S3C64XX_SPI_MODE_CH_TSZ_HALFWORD (1<<29)
63#define S3C64XX_SPI_MODE_CH_TSZ_WORD (2<<29)
64#define S3C64XX_SPI_MODE_CH_TSZ_MASK (3<<29)
65#define S3C64XX_SPI_MODE_BUS_TSZ_BYTE (0<<17)
66#define S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD (1<<17)
67#define S3C64XX_SPI_MODE_BUS_TSZ_WORD (2<<17)
68#define S3C64XX_SPI_MODE_BUS_TSZ_MASK (3<<17)
69#define S3C64XX_SPI_MODE_RXDMA_ON (1<<2)
70#define S3C64XX_SPI_MODE_TXDMA_ON (1<<1)
71#define S3C64XX_SPI_MODE_4BURST (1<<0)
72
73#define S3C64XX_SPI_SLAVE_AUTO (1<<1)
74#define S3C64XX_SPI_SLAVE_SIG_INACT (1<<0)
75
76#define S3C64XX_SPI_ACT(c) writel(0, (c)->regs + S3C64XX_SPI_SLAVE_SEL)
77
78#define S3C64XX_SPI_DEACT(c) writel(S3C64XX_SPI_SLAVE_SIG_INACT, \
79 (c)->regs + S3C64XX_SPI_SLAVE_SEL)
80
81#define S3C64XX_SPI_INT_TRAILING_EN (1<<6)
82#define S3C64XX_SPI_INT_RX_OVERRUN_EN (1<<5)
83#define S3C64XX_SPI_INT_RX_UNDERRUN_EN (1<<4)
84#define S3C64XX_SPI_INT_TX_OVERRUN_EN (1<<3)
85#define S3C64XX_SPI_INT_TX_UNDERRUN_EN (1<<2)
86#define S3C64XX_SPI_INT_RX_FIFORDY_EN (1<<1)
87#define S3C64XX_SPI_INT_TX_FIFORDY_EN (1<<0)
88
89#define S3C64XX_SPI_ST_RX_OVERRUN_ERR (1<<5)
90#define S3C64XX_SPI_ST_RX_UNDERRUN_ERR (1<<4)
91#define S3C64XX_SPI_ST_TX_OVERRUN_ERR (1<<3)
92#define S3C64XX_SPI_ST_TX_UNDERRUN_ERR (1<<2)
93#define S3C64XX_SPI_ST_RX_FIFORDY (1<<1)
94#define S3C64XX_SPI_ST_TX_FIFORDY (1<<0)
95
96#define S3C64XX_SPI_PACKET_CNT_EN (1<<16)
97
98#define S3C64XX_SPI_PND_TX_UNDERRUN_CLR (1<<4)
99#define S3C64XX_SPI_PND_TX_OVERRUN_CLR (1<<3)
100#define S3C64XX_SPI_PND_RX_UNDERRUN_CLR (1<<2)
101#define S3C64XX_SPI_PND_RX_OVERRUN_CLR (1<<1)
102#define S3C64XX_SPI_PND_TRAILING_CLR (1<<0)
103
104#define S3C64XX_SPI_SWAP_RX_HALF_WORD (1<<7)
105#define S3C64XX_SPI_SWAP_RX_BYTE (1<<6)
106#define S3C64XX_SPI_SWAP_RX_BIT (1<<5)
107#define S3C64XX_SPI_SWAP_RX_EN (1<<4)
108#define S3C64XX_SPI_SWAP_TX_HALF_WORD (1<<3)
109#define S3C64XX_SPI_SWAP_TX_BYTE (1<<2)
110#define S3C64XX_SPI_SWAP_TX_BIT (1<<1)
111#define S3C64XX_SPI_SWAP_TX_EN (1<<0)
112
113#define S3C64XX_SPI_FBCLK_MSK (3<<0)
114
115#define S3C64XX_SPI_ST_TRLCNTZ(v, i) ((((v) >> (i)->rx_lvl_offset) & \
116 (((i)->fifo_lvl_mask + 1))) \
117 ? 1 : 0)
118
119#define S3C64XX_SPI_ST_TX_DONE(v, i) ((((v) >> (i)->rx_lvl_offset) & \
120 (((i)->fifo_lvl_mask + 1) << 1)) \
121 ? 1 : 0)
122#define TX_FIFO_LVL(v, i) (((v) >> 6) & (i)->fifo_lvl_mask)
123#define RX_FIFO_LVL(v, i) (((v) >> (i)->rx_lvl_offset) & (i)->fifo_lvl_mask)
124
125#define S3C64XX_SPI_MAX_TRAILCNT 0x3ff
126#define S3C64XX_SPI_TRAILCNT_OFF 19
127
128#define S3C64XX_SPI_TRAILCNT S3C64XX_SPI_MAX_TRAILCNT
129
130#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
131
132#define SUSPND (1<<0)
133#define SPIBUSY (1<<1)
134#define RXBUSY (1<<2)
135#define TXBUSY (1<<3)
136
137/**
138 * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
139 * @clk: Pointer to the spi clock.
140 * @master: Pointer to the SPI Protocol master.
141 * @workqueue: Work queue for the SPI xfer requests.
142 * @cntrlr_info: Platform specific data for the controller this driver manages.
143 * @tgl_spi: Pointer to the last CS left untoggled by the cs_change hint.
144 * @work: Work
145 * @queue: To log SPI xfer requests.
146 * @lock: Controller specific lock.
147 * @state: Set of FLAGS to indicate status.
148 * @rx_dmach: Controller's DMA channel for Rx.
149 * @tx_dmach: Controller's DMA channel for Tx.
150 * @sfr_start: BUS address of SPI controller regs.
151 * @regs: Pointer to ioremap'ed controller registers.
152 * @xfer_completion: To indicate completion of xfer task.
153 * @cur_mode: Stores the active configuration of the controller.
154 * @cur_bpw: Stores the active bits per word settings.
155 * @cur_speed: Stores the active xfer clock speed.
156 */
157struct s3c64xx_spi_driver_data {
158 void __iomem *regs;
159 struct clk *clk;
160 struct platform_device *pdev;
161 struct spi_master *master;
162 struct workqueue_struct *workqueue;
ad7de729 163 struct s3c64xx_spi_info *cntrlr_info;
230d42d4
JB		 164 struct spi_device *tgl_spi;
165 struct work_struct work;
166 struct list_head queue;
167 spinlock_t lock;
168 enum dma_ch rx_dmach;
169 enum dma_ch tx_dmach;
170 unsigned long sfr_start;
171 struct completion xfer_completion;
172 unsigned state;
173 unsigned cur_mode, cur_bpw;
174 unsigned cur_speed;
175};
176
177static struct s3c2410_dma_client s3c64xx_spi_dma_client = {
178 .name = "samsung-spi-dma",
179};
180
181static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
182{
ad7de729 183 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
230d42d4
JB		 184 void __iomem *regs = sdd->regs;
185 unsigned long loops;
186 u32 val;
187
188 writel(0, regs + S3C64XX_SPI_PACKET_CNT);
189
190 val = readl(regs + S3C64XX_SPI_CH_CFG);
191 val |= S3C64XX_SPI_CH_SW_RST;
192 val &= ~S3C64XX_SPI_CH_HS_EN;
193 writel(val, regs + S3C64XX_SPI_CH_CFG);
194
195 /* Flush TxFIFO*/
196 loops = msecs_to_loops(1);
197 do {
198 val = readl(regs + S3C64XX_SPI_STATUS);
199 } while (TX_FIFO_LVL(val, sci) && loops--);
200
201 /* Flush RxFIFO*/
202 loops = msecs_to_loops(1);
203 do {
204 val = readl(regs + S3C64XX_SPI_STATUS);
205 if (RX_FIFO_LVL(val, sci))
206 readl(regs + S3C64XX_SPI_RX_DATA);
207 else
208 break;
209 } while (loops--);
210
211 val = readl(regs + S3C64XX_SPI_CH_CFG);
212 val &= ~S3C64XX_SPI_CH_SW_RST;
213 writel(val, regs + S3C64XX_SPI_CH_CFG);
214
215 val = readl(regs + S3C64XX_SPI_MODE_CFG);
216 val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
217 writel(val, regs + S3C64XX_SPI_MODE_CFG);
218
219 val = readl(regs + S3C64XX_SPI_CH_CFG);
220 val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON);
221 writel(val, regs + S3C64XX_SPI_CH_CFG);
222}
223
224static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
225 struct spi_device *spi,
226 struct spi_transfer *xfer, int dma_mode)
227{
ad7de729 228 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
230d42d4
JB		 229 void __iomem *regs = sdd->regs;
230 u32 modecfg, chcfg;
231
232 modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
233 modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
234
235 chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
236 chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
237
238 if (dma_mode) {
239 chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
240 } else {
241 /* Always shift in data in FIFO, even if xfer is Tx only,
242 * this helps setting PCKT_CNT value for generating clocks
243 * as exactly needed.
244 */
245 chcfg |= S3C64XX_SPI_CH_RXCH_ON;
246 writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
247 | S3C64XX_SPI_PACKET_CNT_EN,
248 regs + S3C64XX_SPI_PACKET_CNT);
249 }
250
251 if (xfer->tx_buf != NULL) {
252 sdd->state |= TXBUSY;
253 chcfg |= S3C64XX_SPI_CH_TXCH_ON;
254 if (dma_mode) {
255 modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
256 s3c2410_dma_config(sdd->tx_dmach, 1);
257 s3c2410_dma_enqueue(sdd->tx_dmach, (void *)sdd,
258 xfer->tx_dma, xfer->len);
259 s3c2410_dma_ctrl(sdd->tx_dmach, S3C2410_DMAOP_START);
260 } else {
261 unsigned char *buf = (unsigned char *) xfer->tx_buf;
262 int i = 0;
263 while (i < xfer->len)
264 writeb(buf[i++], regs + S3C64XX_SPI_TX_DATA);
265 }
266 }
267
268 if (xfer->rx_buf != NULL) {
269 sdd->state |= RXBUSY;
270
271 if (sci->high_speed && sdd->cur_speed >= 30000000UL
272 && !(sdd->cur_mode & SPI_CPHA))
273 chcfg |= S3C64XX_SPI_CH_HS_EN;
274
275 if (dma_mode) {
276 modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
277 chcfg |= S3C64XX_SPI_CH_RXCH_ON;
278 writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
279 | S3C64XX_SPI_PACKET_CNT_EN,
280 regs + S3C64XX_SPI_PACKET_CNT);
281 s3c2410_dma_config(sdd->rx_dmach, 1);
282 s3c2410_dma_enqueue(sdd->rx_dmach, (void *)sdd,
283 xfer->rx_dma, xfer->len);
284 s3c2410_dma_ctrl(sdd->rx_dmach, S3C2410_DMAOP_START);
285 }
286 }
287
288 writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
289 writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
290}
291
292static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd,
293 struct spi_device *spi)
294{
295 struct s3c64xx_spi_csinfo *cs;
296
297 if (sdd->tgl_spi != NULL) { /* If last device toggled after mssg */
298 if (sdd->tgl_spi != spi) { /* if last mssg on diff device */
299 /* Deselect the last toggled device */
300 cs = sdd->tgl_spi->controller_data;
301 cs->set_level(spi->mode & SPI_CS_HIGH ? 0 : 1);
302 }
303 sdd->tgl_spi = NULL;
304 }
305
306 cs = spi->controller_data;
307 cs->set_level(spi->mode & SPI_CS_HIGH ? 1 : 0);
308}
309
310static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
311 struct spi_transfer *xfer, int dma_mode)
312{
ad7de729 313 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
230d42d4
JB		 314 void __iomem *regs = sdd->regs;
315 unsigned long val;
316 int ms;
317
318 /* millisecs to xfer 'len' bytes @ 'cur_speed' */
319 ms = xfer->len * 8 * 1000 / sdd->cur_speed;
320 ms += 5; /* some tolerance */
321
322 if (dma_mode) {
323 val = msecs_to_jiffies(ms) + 10;
324 val = wait_for_completion_timeout(&sdd->xfer_completion, val);
325 } else {
326 val = msecs_to_loops(ms);
327 do {
328 val = readl(regs + S3C64XX_SPI_STATUS);
329 } while (RX_FIFO_LVL(val, sci) < xfer->len && --val);
330 }
331
332 if (!val)
333 return -EIO;
334
335 if (dma_mode) {
336 u32 status;
337
338 /*
339 * DmaTx returns after simply writing data in the FIFO,
340 * w/o waiting for real transmission on the bus to finish.
341 * DmaRx returns only after Dma read data from FIFO which
342 * needs bus transmission to finish, so we don't worry if
343 * Xfer involved Rx(with or without Tx).
344 */
345 if (xfer->rx_buf == NULL) {
346 val = msecs_to_loops(10);
347 status = readl(regs + S3C64XX_SPI_STATUS);
348 while ((TX_FIFO_LVL(status, sci)
349 || !S3C64XX_SPI_ST_TX_DONE(status, sci))
350 && --val) {
351 cpu_relax();
352 status = readl(regs + S3C64XX_SPI_STATUS);
353 }
354
355 if (!val)
356 return -EIO;
357 }
358 } else {
359 unsigned char *buf;
360 int i;
361
362 /* If it was only Tx */
363 if (xfer->rx_buf == NULL) {
364 sdd->state &= ~TXBUSY;
365 return 0;
366 }
367
368 i = 0;
369 buf = xfer->rx_buf;
370 while (i < xfer->len)
371 buf[i++] = readb(regs + S3C64XX_SPI_RX_DATA);
372
373 sdd->state &= ~RXBUSY;
374 }
375
376 return 0;
377}
378
379static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd,
380 struct spi_device *spi)
381{
382 struct s3c64xx_spi_csinfo *cs = spi->controller_data;
383
384 if (sdd->tgl_spi == spi)
385 sdd->tgl_spi = NULL;
386
387 cs->set_level(spi->mode & SPI_CS_HIGH ? 0 : 1);
388}
389
390static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
391{
ad7de729 392 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
230d42d4
JB		 393 void __iomem *regs = sdd->regs;
394 u32 val;
395
396 /* Disable Clock */
397 val = readl(regs + S3C64XX_SPI_CLK_CFG);
398 val &= ~S3C64XX_SPI_ENCLK_ENABLE;
399 writel(val, regs + S3C64XX_SPI_CLK_CFG);
400
401 /* Set Polarity and Phase */
402 val = readl(regs + S3C64XX_SPI_CH_CFG);
403 val &= ~(S3C64XX_SPI_CH_SLAVE |
404 S3C64XX_SPI_CPOL_L |
405 S3C64XX_SPI_CPHA_B);
406
407 if (sdd->cur_mode & SPI_CPOL)
408 val |= S3C64XX_SPI_CPOL_L;
409
410 if (sdd->cur_mode & SPI_CPHA)
411 val |= S3C64XX_SPI_CPHA_B;
412
413 writel(val, regs + S3C64XX_SPI_CH_CFG);
414
415 /* Set Channel & DMA Mode */
416 val = readl(regs + S3C64XX_SPI_MODE_CFG);
417 val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
418 | S3C64XX_SPI_MODE_CH_TSZ_MASK);
419
420 switch (sdd->cur_bpw) {
421 case 32:
422 val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
423 break;
424 case 16:
425 val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
426 break;
427 default:
428 val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
429 break;
430 }
431 val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE; /* Always 8bits wide */
432
433 writel(val, regs + S3C64XX_SPI_MODE_CFG);
434
435 /* Configure Clock */
436 val = readl(regs + S3C64XX_SPI_CLK_CFG);
437 val &= ~S3C64XX_SPI_PSR_MASK;
438 val |= ((clk_get_rate(sci->src_clk) / sdd->cur_speed / 2 - 1)
439 & S3C64XX_SPI_PSR_MASK);
440 writel(val, regs + S3C64XX_SPI_CLK_CFG);
441
442 /* Enable Clock */
443 val = readl(regs + S3C64XX_SPI_CLK_CFG);
444 val |= S3C64XX_SPI_ENCLK_ENABLE;
445 writel(val, regs + S3C64XX_SPI_CLK_CFG);
446}
447
448void s3c64xx_spi_dma_rxcb(struct s3c2410_dma_chan *chan, void *buf_id,
449 int size, enum s3c2410_dma_buffresult res)
450{
451 struct s3c64xx_spi_driver_data *sdd = buf_id;
452 unsigned long flags;
453
454 spin_lock_irqsave(&sdd->lock, flags);
455
456 if (res == S3C2410_RES_OK)
457 sdd->state &= ~RXBUSY;
458 else
459 dev_err(&sdd->pdev->dev, "DmaAbrtRx-%d\n", size);
460
461 /* If the other done */
462 if (!(sdd->state & TXBUSY))
463 complete(&sdd->xfer_completion);
464
465 spin_unlock_irqrestore(&sdd->lock, flags);
466}
467
468void s3c64xx_spi_dma_txcb(struct s3c2410_dma_chan *chan, void *buf_id,
469 int size, enum s3c2410_dma_buffresult res)
470{
471 struct s3c64xx_spi_driver_data *sdd = buf_id;
472 unsigned long flags;
473
474 spin_lock_irqsave(&sdd->lock, flags);
475
476 if (res == S3C2410_RES_OK)
477 sdd->state &= ~TXBUSY;
478 else
479 dev_err(&sdd->pdev->dev, "DmaAbrtTx-%d \n", size);
480
481 /* If the other done */
482 if (!(sdd->state & RXBUSY))
483 complete(&sdd->xfer_completion);
484
485 spin_unlock_irqrestore(&sdd->lock, flags);
486}
487
488#define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
489
490static int s3c64xx_spi_map_mssg(struct s3c64xx_spi_driver_data *sdd,
491 struct spi_message *msg)
492{
493 struct device *dev = &sdd->pdev->dev;
494 struct spi_transfer *xfer;
495
496 if (msg->is_dma_mapped)
497 return 0;
498
499 /* First mark all xfer unmapped */
500 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
501 xfer->rx_dma = XFER_DMAADDR_INVALID;
502 xfer->tx_dma = XFER_DMAADDR_INVALID;
503 }
504
505 /* Map until end or first fail */
506 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
507
508 if (xfer->tx_buf != NULL) {
509 xfer->tx_dma = dma_map_single(dev, xfer->tx_buf,
510 xfer->len, DMA_TO_DEVICE);
511 if (dma_mapping_error(dev, xfer->tx_dma)) {
512 dev_err(dev, "dma_map_single Tx failed\n");
513 xfer->tx_dma = XFER_DMAADDR_INVALID;
514 return -ENOMEM;
515 }
516 }
517
518 if (xfer->rx_buf != NULL) {
519 xfer->rx_dma = dma_map_single(dev, xfer->rx_buf,
520 xfer->len, DMA_FROM_DEVICE);
521 if (dma_mapping_error(dev, xfer->rx_dma)) {
522 dev_err(dev, "dma_map_single Rx failed\n");
523 dma_unmap_single(dev, xfer->tx_dma,
524 xfer->len, DMA_TO_DEVICE);
525 xfer->tx_dma = XFER_DMAADDR_INVALID;
526 xfer->rx_dma = XFER_DMAADDR_INVALID;
527 return -ENOMEM;
528 }
529 }
530 }
531
532 return 0;
533}
534
535static void s3c64xx_spi_unmap_mssg(struct s3c64xx_spi_driver_data *sdd,
536 struct spi_message *msg)
537{
538 struct device *dev = &sdd->pdev->dev;
539 struct spi_transfer *xfer;
540
541 if (msg->is_dma_mapped)
542 return;
543
544 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
545
546 if (xfer->rx_buf != NULL
547 && xfer->rx_dma != XFER_DMAADDR_INVALID)
548 dma_unmap_single(dev, xfer->rx_dma,
549 xfer->len, DMA_FROM_DEVICE);
550
551 if (xfer->tx_buf != NULL
552 && xfer->tx_dma != XFER_DMAADDR_INVALID)
553 dma_unmap_single(dev, xfer->tx_dma,
554 xfer->len, DMA_TO_DEVICE);
555 }
556}
557
558static void handle_msg(struct s3c64xx_spi_driver_data *sdd,
559 struct spi_message *msg)
560{
ad7de729 561 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
230d42d4
JB		 562 struct spi_device *spi = msg->spi;
563 struct s3c64xx_spi_csinfo *cs = spi->controller_data;
564 struct spi_transfer *xfer;
565 int status = 0, cs_toggle = 0;
566 u32 speed;
567 u8 bpw;
568
569 /* If Master's(controller) state differs from that needed by Slave */
570 if (sdd->cur_speed != spi->max_speed_hz
571 || sdd->cur_mode != spi->mode
572 || sdd->cur_bpw != spi->bits_per_word) {
573 sdd->cur_bpw = spi->bits_per_word;
574 sdd->cur_speed = spi->max_speed_hz;
575 sdd->cur_mode = spi->mode;
576 s3c64xx_spi_config(sdd);
577 }
578
579 /* Map all the transfers if needed */
580 if (s3c64xx_spi_map_mssg(sdd, msg)) {
581 dev_err(&spi->dev,
582 "Xfer: Unable to map message buffers!\n");
583 status = -ENOMEM;
584 goto out;
585 }
586
587 /* Configure feedback delay */
588 writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
589
590 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
591
592 unsigned long flags;
593 int use_dma;
594
595 INIT_COMPLETION(sdd->xfer_completion);
596
597 /* Only BPW and Speed may change across transfers */
598 bpw = xfer->bits_per_word ? : spi->bits_per_word;
599 speed = xfer->speed_hz ? : spi->max_speed_hz;
600
601 if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
602 sdd->cur_bpw = bpw;
603 sdd->cur_speed = speed;
604 s3c64xx_spi_config(sdd);
605 }
606
607 /* Polling method for xfers not bigger than FIFO capacity */
608 if (xfer->len <= ((sci->fifo_lvl_mask >> 1) + 1))
609 use_dma = 0;
610 else
611 use_dma = 1;
612
613 spin_lock_irqsave(&sdd->lock, flags);
614
615 /* Pending only which is to be done */
616 sdd->state &= ~RXBUSY;
617 sdd->state &= ~TXBUSY;
618
619 enable_datapath(sdd, spi, xfer, use_dma);
620
621 /* Slave Select */
622 enable_cs(sdd, spi);
623
624 /* Start the signals */
625 S3C64XX_SPI_ACT(sdd);
626
627 spin_unlock_irqrestore(&sdd->lock, flags);
628
629 status = wait_for_xfer(sdd, xfer, use_dma);
630
631 /* Quiese the signals */
632 S3C64XX_SPI_DEACT(sdd);
633
634 if (status) {
635 dev_err(&spi->dev, "I/O Error: \
636 rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
637 xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
638 (sdd->state & RXBUSY) ? 'f' : 'p',
639 (sdd->state & TXBUSY) ? 'f' : 'p',
640 xfer->len);
641
642 if (use_dma) {
643 if (xfer->tx_buf != NULL
644 && (sdd->state & TXBUSY))
645 s3c2410_dma_ctrl(sdd->tx_dmach,
646 S3C2410_DMAOP_FLUSH);
647 if (xfer->rx_buf != NULL
648 && (sdd->state & RXBUSY))
649 s3c2410_dma_ctrl(sdd->rx_dmach,
650 S3C2410_DMAOP_FLUSH);
651 }
652
653 goto out;
654 }
655
656 if (xfer->delay_usecs)
657 udelay(xfer->delay_usecs);
658
659 if (xfer->cs_change) {
660 /* Hint that the next mssg is gonna be
661 for the same device */
662 if (list_is_last(&xfer->transfer_list,
663 &msg->transfers))
664 cs_toggle = 1;
665 else
666 disable_cs(sdd, spi);
667 }
668
669 msg->actual_length += xfer->len;
670
671 flush_fifo(sdd);
672 }
673
674out:
675 if (!cs_toggle || status)
676 disable_cs(sdd, spi);
677 else
678 sdd->tgl_spi = spi;
679
680 s3c64xx_spi_unmap_mssg(sdd, msg);
681
682 msg->status = status;
683
684 if (msg->complete)
685 msg->complete(msg->context);
686}
687
688static int acquire_dma(struct s3c64xx_spi_driver_data *sdd)
689{
690 if (s3c2410_dma_request(sdd->rx_dmach,
691 &s3c64xx_spi_dma_client, NULL) < 0) {
692 dev_err(&sdd->pdev->dev, "cannot get RxDMA\n");
693 return 0;
694 }
695 s3c2410_dma_set_buffdone_fn(sdd->rx_dmach, s3c64xx_spi_dma_rxcb);
696 s3c2410_dma_devconfig(sdd->rx_dmach, S3C2410_DMASRC_HW,
697 sdd->sfr_start + S3C64XX_SPI_RX_DATA);
698
699 if (s3c2410_dma_request(sdd->tx_dmach,
700 &s3c64xx_spi_dma_client, NULL) < 0) {
701 dev_err(&sdd->pdev->dev, "cannot get TxDMA\n");
702 s3c2410_dma_free(sdd->rx_dmach, &s3c64xx_spi_dma_client);
703 return 0;
704 }
705 s3c2410_dma_set_buffdone_fn(sdd->tx_dmach, s3c64xx_spi_dma_txcb);
706 s3c2410_dma_devconfig(sdd->tx_dmach, S3C2410_DMASRC_MEM,
707 sdd->sfr_start + S3C64XX_SPI_TX_DATA);
708
709 return 1;
710}
711
712static void s3c64xx_spi_work(struct work_struct *work)
713{
714 struct s3c64xx_spi_driver_data *sdd = container_of(work,
715 struct s3c64xx_spi_driver_data, work);
716 unsigned long flags;
717
718 /* Acquire DMA channels */
719 while (!acquire_dma(sdd))
720 msleep(10);
721
722 spin_lock_irqsave(&sdd->lock, flags);
723
724 while (!list_empty(&sdd->queue)
725 && !(sdd->state & SUSPND)) {
726
727 struct spi_message *msg;
728
729 msg = container_of(sdd->queue.next, struct spi_message, queue);
730
731 list_del_init(&msg->queue);
732
733 /* Set Xfer busy flag */
734 sdd->state |= SPIBUSY;
735
736 spin_unlock_irqrestore(&sdd->lock, flags);
737
738 handle_msg(sdd, msg);
739
740 spin_lock_irqsave(&sdd->lock, flags);
741
742 sdd->state &= ~SPIBUSY;
743 }
744
745 spin_unlock_irqrestore(&sdd->lock, flags);
746
747 /* Free DMA channels */
748 s3c2410_dma_free(sdd->tx_dmach, &s3c64xx_spi_dma_client);
749 s3c2410_dma_free(sdd->rx_dmach, &s3c64xx_spi_dma_client);
750}
751
752static int s3c64xx_spi_transfer(struct spi_device *spi,
753 struct spi_message *msg)
754{
755 struct s3c64xx_spi_driver_data *sdd;
756 unsigned long flags;
757
758 sdd = spi_master_get_devdata(spi->master);
759
760 spin_lock_irqsave(&sdd->lock, flags);
761
762 if (sdd->state & SUSPND) {
763 spin_unlock_irqrestore(&sdd->lock, flags);
764 return -ESHUTDOWN;
765 }
766
767 msg->status = -EINPROGRESS;
768 msg->actual_length = 0;
769
770 list_add_tail(&msg->queue, &sdd->queue);
771
772 queue_work(sdd->workqueue, &sdd->work);
773
774 spin_unlock_irqrestore(&sdd->lock, flags);
775
776 return 0;
777}
778
779/*
780 * Here we only check the validity of requested configuration
781 * and save the configuration in a local data-structure.
782 * The controller is actually configured only just before we
783 * get a message to transfer.
784 */
785static int s3c64xx_spi_setup(struct spi_device *spi)
786{
787 struct s3c64xx_spi_csinfo *cs = spi->controller_data;
788 struct s3c64xx_spi_driver_data *sdd;
ad7de729 789 struct s3c64xx_spi_info *sci;
230d42d4
JB		 790 struct spi_message *msg;
791 u32 psr, speed;
792 unsigned long flags;
793 int err = 0;
794
795 if (cs == NULL || cs->set_level == NULL) {
796 dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
797 return -ENODEV;
798 }
799
800 sdd = spi_master_get_devdata(spi->master);
801 sci = sdd->cntrlr_info;
802
803 spin_lock_irqsave(&sdd->lock, flags);
804
805 list_for_each_entry(msg, &sdd->queue, queue) {
806 /* Is some mssg is already queued for this device */
807 if (msg->spi == spi) {
808 dev_err(&spi->dev,
809 "setup: attempt while mssg in queue!\n");
810 spin_unlock_irqrestore(&sdd->lock, flags);
811 return -EBUSY;
812 }
813 }
814
815 if (sdd->state & SUSPND) {
816 spin_unlock_irqrestore(&sdd->lock, flags);
817 dev_err(&spi->dev,
818 "setup: SPI-%d not active!\n", spi->master->bus_num);
819 return -ESHUTDOWN;
820 }
821
822 spin_unlock_irqrestore(&sdd->lock, flags);
823
824 if (spi->bits_per_word != 8
825 && spi->bits_per_word != 16
826 && spi->bits_per_word != 32) {
827 dev_err(&spi->dev, "setup: %dbits/wrd not supported!\n",
828 spi->bits_per_word);
829 err = -EINVAL;
830 goto setup_exit;
831 }
832
833 /* Check if we can provide the requested rate */
834 speed = clk_get_rate(sci->src_clk) / 2 / (0 + 1); /* Max possible */
835
836 if (spi->max_speed_hz > speed)
837 spi->max_speed_hz = speed;
838
839 psr = clk_get_rate(sci->src_clk) / 2 / spi->max_speed_hz - 1;
840 psr &= S3C64XX_SPI_PSR_MASK;
841 if (psr == S3C64XX_SPI_PSR_MASK)
842 psr--;
843
844 speed = clk_get_rate(sci->src_clk) / 2 / (psr + 1);
845 if (spi->max_speed_hz < speed) {
846 if (psr+1 < S3C64XX_SPI_PSR_MASK) {
847 psr++;
848 } else {
849 err = -EINVAL;
850 goto setup_exit;
851 }
852 }
853
854 speed = clk_get_rate(sci->src_clk) / 2 / (psr + 1);
855 if (spi->max_speed_hz >= speed)
856 spi->max_speed_hz = speed;
857 else
858 err = -EINVAL;
859
860setup_exit:
861
862 /* setup() returns with device de-selected */
863 disable_cs(sdd, spi);
864
865 return err;
866}
867
868static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel)
869{
ad7de729 870 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
230d42d4
JB		 871 void __iomem *regs = sdd->regs;
872 unsigned int val;
873
874 sdd->cur_speed = 0;
875
876 S3C64XX_SPI_DEACT(sdd);
877
878 /* Disable Interrupts - we use Polling if not DMA mode */
879 writel(0, regs + S3C64XX_SPI_INT_EN);
880
881 writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
882 regs + S3C64XX_SPI_CLK_CFG);
883 writel(0, regs + S3C64XX_SPI_MODE_CFG);
884 writel(0, regs + S3C64XX_SPI_PACKET_CNT);
885
886 /* Clear any irq pending bits */
887 writel(readl(regs + S3C64XX_SPI_PENDING_CLR),
888 regs + S3C64XX_SPI_PENDING_CLR);
889
890 writel(0, regs + S3C64XX_SPI_SWAP_CFG);
891
892 val = readl(regs + S3C64XX_SPI_MODE_CFG);
893 val &= ~S3C64XX_SPI_MODE_4BURST;
894 val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
895 val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
896 writel(val, regs + S3C64XX_SPI_MODE_CFG);
897
898 flush_fifo(sdd);
899}
900
901static int __init s3c64xx_spi_probe(struct platform_device *pdev)
902{
903 struct resource *mem_res, *dmatx_res, *dmarx_res;
904 struct s3c64xx_spi_driver_data *sdd;
ad7de729 905 struct s3c64xx_spi_info *sci;
230d42d4
JB		 906 struct spi_master *master;
907 int ret;
908
909 if (pdev->id < 0) {
910 dev_err(&pdev->dev,
911 "Invalid platform device id-%d\n", pdev->id);
912 return -ENODEV;
913 }
914
915 if (pdev->dev.platform_data == NULL) {
916 dev_err(&pdev->dev, "platform_data missing!\n");
917 return -ENODEV;
918 }
919
920 /* Check for availability of necessary resource */
921
922 dmatx_res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
923 if (dmatx_res == NULL) {
924 dev_err(&pdev->dev, "Unable to get SPI-Tx dma resource\n");
925 return -ENXIO;
926 }
927
928 dmarx_res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
929 if (dmarx_res == NULL) {
930 dev_err(&pdev->dev, "Unable to get SPI-Rx dma resource\n");
931 return -ENXIO;
932 }
933
934 mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
935 if (mem_res == NULL) {
936 dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
937 return -ENXIO;
938 }
939
940 master = spi_alloc_master(&pdev->dev,
941 sizeof(struct s3c64xx_spi_driver_data));
942 if (master == NULL) {
943 dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
944 return -ENOMEM;
945 }
946
947 sci = pdev->dev.platform_data;
948
949 platform_set_drvdata(pdev, master);
950
951 sdd = spi_master_get_devdata(master);
952 sdd->master = master;
953 sdd->cntrlr_info = sci;
954 sdd->pdev = pdev;
955 sdd->sfr_start = mem_res->start;
956 sdd->tx_dmach = dmatx_res->start;
957 sdd->rx_dmach = dmarx_res->start;
958
959 sdd->cur_bpw = 8;
960
961 master->bus_num = pdev->id;
962 master->setup = s3c64xx_spi_setup;
963 master->transfer = s3c64xx_spi_transfer;
964 master->num_chipselect = sci->num_cs;
965 master->dma_alignment = 8;
966 /* the spi->mode bits understood by this driver: */
967 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
968
969 if (request_mem_region(mem_res->start,
970 resource_size(mem_res), pdev->name) == NULL) {
971 dev_err(&pdev->dev, "Req mem region failed\n");
972 ret = -ENXIO;
973 goto err0;
974 }
975
976 sdd->regs = ioremap(mem_res->start, resource_size(mem_res));
977 if (sdd->regs == NULL) {
978 dev_err(&pdev->dev, "Unable to remap IO\n");
979 ret = -ENXIO;
980 goto err1;
981 }
982
983 if (sci->cfg_gpio == NULL || sci->cfg_gpio(pdev)) {
984 dev_err(&pdev->dev, "Unable to config gpio\n");
985 ret = -EBUSY;
986 goto err2;
987 }
988
989 /* Setup clocks */
990 sdd->clk = clk_get(&pdev->dev, "spi");
991 if (IS_ERR(sdd->clk)) {
992 dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
993 ret = PTR_ERR(sdd->clk);
994 goto err3;
995 }
996
997 if (clk_enable(sdd->clk)) {
998 dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
999 ret = -EBUSY;
1000 goto err4;
1001 }
1002
ee64a377 1003 sci->src_clk = clk_get(&pdev->dev, sci->src_clk_name);
230d42d4
JB		 1004 if (IS_ERR(sci->src_clk)) {
1005 dev_err(&pdev->dev,
1006 "Unable to acquire clock '%s'\n", sci->src_clk_name);
1007 ret = PTR_ERR(sci->src_clk);
1008 goto err5;
1009 }
1010
ee64a377 1011 if (clk_enable(sci->src_clk)) {
230d42d4
JB		 1012 dev_err(&pdev->dev, "Couldn't enable clock '%s'\n",
1013 sci->src_clk_name);
1014 ret = -EBUSY;
1015 goto err6;
1016 }
1017
1018 sdd->workqueue = create_singlethread_workqueue(
1019 dev_name(master->dev.parent));
1020 if (sdd->workqueue == NULL) {
1021 dev_err(&pdev->dev, "Unable to create workqueue\n");
1022 ret = -ENOMEM;
1023 goto err7;
1024 }
1025
1026 /* Setup Deufult Mode */
1027 s3c64xx_spi_hwinit(sdd, pdev->id);
1028
1029 spin_lock_init(&sdd->lock);
1030 init_completion(&sdd->xfer_completion);
1031 INIT_WORK(&sdd->work, s3c64xx_spi_work);
1032 INIT_LIST_HEAD(&sdd->queue);
1033
1034 if (spi_register_master(master)) {
1035 dev_err(&pdev->dev, "cannot register SPI master\n");
1036 ret = -EBUSY;
1037 goto err8;
1038 }
1039
1040 dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d \
1041 with %d Slaves attached\n",
1042 pdev->id, master->num_chipselect);
1043 dev_dbg(&pdev->dev, "\tIOmem=[0x%x-0x%x]\
1044 \tDMA=[Rx-%d, Tx-%d]\n",
1045 mem_res->end, mem_res->start,
1046 sdd->rx_dmach, sdd->tx_dmach);
1047
1048 return 0;
1049
1050err8:
1051 destroy_workqueue(sdd->workqueue);
1052err7:
ee64a377 1053 clk_disable(sci->src_clk);
230d42d4 1054err6:
ee64a377 1055 clk_put(sci->src_clk);
230d42d4
JB		 1056err5:
1057 clk_disable(sdd->clk);
1058err4:
1059 clk_put(sdd->clk);
1060err3:
1061err2:
1062 iounmap((void *) sdd->regs);
1063err1:
1064 release_mem_region(mem_res->start, resource_size(mem_res));
1065err0:
1066 platform_set_drvdata(pdev, NULL);
1067 spi_master_put(master);
1068
1069 return ret;
1070}
1071
1072static int s3c64xx_spi_remove(struct platform_device *pdev)
1073{
1074 struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
1075 struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
ad7de729 1076 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
230d42d4
JB		 1077 struct resource *mem_res;
1078 unsigned long flags;
1079
1080 spin_lock_irqsave(&sdd->lock, flags);
1081 sdd->state |= SUSPND;
1082 spin_unlock_irqrestore(&sdd->lock, flags);
1083
1084 while (sdd->state & SPIBUSY)
1085 msleep(10);
1086
1087 spi_unregister_master(master);
1088
1089 destroy_workqueue(sdd->workqueue);
1090
ee64a377
JB		 1091 clk_disable(sci->src_clk);
1092 clk_put(sci->src_clk);
230d42d4
JB		 1093
1094 clk_disable(sdd->clk);
1095 clk_put(sdd->clk);
1096
1097 iounmap((void *) sdd->regs);
1098
1099 mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1100 release_mem_region(mem_res->start, resource_size(mem_res));
1101
1102 platform_set_drvdata(pdev, NULL);
1103 spi_master_put(master);
1104
1105 return 0;
1106}
1107
1108#ifdef CONFIG_PM
1109static int s3c64xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
1110{
1111 struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
1112 struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
ad7de729 1113 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
230d42d4
JB		 1114 struct s3c64xx_spi_csinfo *cs;
1115 unsigned long flags;
1116
1117 spin_lock_irqsave(&sdd->lock, flags);
1118 sdd->state |= SUSPND;
1119 spin_unlock_irqrestore(&sdd->lock, flags);
1120
1121 while (sdd->state & SPIBUSY)
1122 msleep(10);
1123
1124 /* Disable the clock */
ee64a377 1125 clk_disable(sci->src_clk);
230d42d4
JB		 1126 clk_disable(sdd->clk);
1127
1128 sdd->cur_speed = 0; /* Output Clock is stopped */
1129
1130 return 0;
1131}
1132
1133static int s3c64xx_spi_resume(struct platform_device *pdev)
1134{
1135 struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
1136 struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
ad7de729 1137 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
230d42d4
JB		 1138 unsigned long flags;
1139
1140 sci->cfg_gpio(pdev);
1141
1142 /* Enable the clock */
ee64a377 1143 clk_enable(sci->src_clk);
230d42d4
JB		 1144 clk_enable(sdd->clk);
1145
1146 s3c64xx_spi_hwinit(sdd, pdev->id);
1147
1148 spin_lock_irqsave(&sdd->lock, flags);
1149 sdd->state &= ~SUSPND;
1150 spin_unlock_irqrestore(&sdd->lock, flags);
1151
1152 return 0;
1153}
1154#else
1155#define s3c64xx_spi_suspend NULL
1156#define s3c64xx_spi_resume NULL
1157#endif /* CONFIG_PM */
1158
1159static struct platform_driver s3c64xx_spi_driver = {
1160 .driver = {
1161 .name = "s3c64xx-spi",
1162 .owner = THIS_MODULE,
1163 },
1164 .remove = s3c64xx_spi_remove,
1165 .suspend = s3c64xx_spi_suspend,
1166 .resume = s3c64xx_spi_resume,
1167};
1168MODULE_ALIAS("platform:s3c64xx-spi");
1169
1170static int __init s3c64xx_spi_init(void)
1171{
1172 return platform_driver_probe(&s3c64xx_spi_driver, s3c64xx_spi_probe);
1173}
1174module_init(s3c64xx_spi_init);
1175
1176static void __exit s3c64xx_spi_exit(void)
1177{
1178 platform_driver_unregister(&s3c64xx_spi_driver);
1179}
1180module_exit(s3c64xx_spi_exit);
1181
1182MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1183MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1184MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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