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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2011-2015 Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
4 * Copyright (C) 2016 Hauke Mehrtens <hauke@hauke-m.de>
5 */
6
7#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/of_device.h>
10#include <linux/clk.h>
11#include <linux/io.h>
12#include <linux/delay.h>
13#include <linux/interrupt.h>
14#include <linux/sched.h>
15#include <linux/completion.h>
16#include <linux/spinlock.h>
17#include <linux/err.h>
18#include <linux/pm_runtime.h>
19#include <linux/spi/spi.h>
20
21#ifdef CONFIG_LANTIQ
22#include <lantiq_soc.h>
23#endif
24
25#define LTQ_SPI_RX_IRQ_NAME "spi_rx"
26#define LTQ_SPI_TX_IRQ_NAME "spi_tx"
27#define LTQ_SPI_ERR_IRQ_NAME "spi_err"
28#define LTQ_SPI_FRM_IRQ_NAME "spi_frm"
29
30#define LTQ_SPI_CLC 0x00
31#define LTQ_SPI_PISEL 0x04
32#define LTQ_SPI_ID 0x08
33#define LTQ_SPI_CON 0x10
34#define LTQ_SPI_STAT 0x14
35#define LTQ_SPI_WHBSTATE 0x18
36#define LTQ_SPI_TB 0x20
37#define LTQ_SPI_RB 0x24
38#define LTQ_SPI_RXFCON 0x30
39#define LTQ_SPI_TXFCON 0x34
40#define LTQ_SPI_FSTAT 0x38
41#define LTQ_SPI_BRT 0x40
42#define LTQ_SPI_BRSTAT 0x44
43#define LTQ_SPI_SFCON 0x60
44#define LTQ_SPI_SFSTAT 0x64
45#define LTQ_SPI_GPOCON 0x70
46#define LTQ_SPI_GPOSTAT 0x74
47#define LTQ_SPI_FPGO 0x78
48#define LTQ_SPI_RXREQ 0x80
49#define LTQ_SPI_RXCNT 0x84
50#define LTQ_SPI_DMACON 0xec
51#define LTQ_SPI_IRNEN 0xf4
52
53#define LTQ_SPI_CLC_SMC_S 16 /* Clock divider for sleep mode */
54#define LTQ_SPI_CLC_SMC_M (0xFF << LTQ_SPI_CLC_SMC_S)
55#define LTQ_SPI_CLC_RMC_S 8 /* Clock divider for normal run mode */
56#define LTQ_SPI_CLC_RMC_M (0xFF << LTQ_SPI_CLC_RMC_S)
57#define LTQ_SPI_CLC_DISS BIT(1) /* Disable status bit */
58#define LTQ_SPI_CLC_DISR BIT(0) /* Disable request bit */
59
60#define LTQ_SPI_ID_TXFS_S 24 /* Implemented TX FIFO size */
61#define LTQ_SPI_ID_RXFS_S 16 /* Implemented RX FIFO size */
62#define LTQ_SPI_ID_MOD_S 8 /* Module ID */
63#define LTQ_SPI_ID_MOD_M (0xff << LTQ_SPI_ID_MOD_S)
64#define LTQ_SPI_ID_CFG_S 5 /* DMA interface support */
65#define LTQ_SPI_ID_CFG_M (1 << LTQ_SPI_ID_CFG_S)
66#define LTQ_SPI_ID_REV_M 0x1F /* Hardware revision number */
67
68#define LTQ_SPI_CON_BM_S 16 /* Data width selection */
69#define LTQ_SPI_CON_BM_M (0x1F << LTQ_SPI_CON_BM_S)
70#define LTQ_SPI_CON_EM BIT(24) /* Echo mode */
71#define LTQ_SPI_CON_IDLE BIT(23) /* Idle bit value */
72#define LTQ_SPI_CON_ENBV BIT(22) /* Enable byte valid control */
73#define LTQ_SPI_CON_RUEN BIT(12) /* Receive underflow error enable */
74#define LTQ_SPI_CON_TUEN BIT(11) /* Transmit underflow error enable */
75#define LTQ_SPI_CON_AEN BIT(10) /* Abort error enable */
76#define LTQ_SPI_CON_REN BIT(9) /* Receive overflow error enable */
77#define LTQ_SPI_CON_TEN BIT(8) /* Transmit overflow error enable */
78#define LTQ_SPI_CON_LB BIT(7) /* Loopback control */
79#define LTQ_SPI_CON_PO BIT(6) /* Clock polarity control */
80#define LTQ_SPI_CON_PH BIT(5) /* Clock phase control */
81#define LTQ_SPI_CON_HB BIT(4) /* Heading control */
82#define LTQ_SPI_CON_RXOFF BIT(1) /* Switch receiver off */
83#define LTQ_SPI_CON_TXOFF BIT(0) /* Switch transmitter off */
84
85#define LTQ_SPI_STAT_RXBV_S 28
86#define LTQ_SPI_STAT_RXBV_M (0x7 << LTQ_SPI_STAT_RXBV_S)
87#define LTQ_SPI_STAT_BSY BIT(13) /* Busy flag */
88#define LTQ_SPI_STAT_RUE BIT(12) /* Receive underflow error flag */
89#define LTQ_SPI_STAT_TUE BIT(11) /* Transmit underflow error flag */
90#define LTQ_SPI_STAT_AE BIT(10) /* Abort error flag */
91#define LTQ_SPI_STAT_RE BIT(9) /* Receive error flag */
92#define LTQ_SPI_STAT_TE BIT(8) /* Transmit error flag */
93#define LTQ_SPI_STAT_ME BIT(7) /* Mode error flag */
94#define LTQ_SPI_STAT_MS BIT(1) /* Master/slave select bit */
95#define LTQ_SPI_STAT_EN BIT(0) /* Enable bit */
96#define LTQ_SPI_STAT_ERRORS (LTQ_SPI_STAT_ME | LTQ_SPI_STAT_TE | \
97 LTQ_SPI_STAT_RE | LTQ_SPI_STAT_AE | \
98 LTQ_SPI_STAT_TUE | LTQ_SPI_STAT_RUE)
99
100#define LTQ_SPI_WHBSTATE_SETTUE BIT(15) /* Set transmit underflow error flag */
101#define LTQ_SPI_WHBSTATE_SETAE BIT(14) /* Set abort error flag */
102#define LTQ_SPI_WHBSTATE_SETRE BIT(13) /* Set receive error flag */
103#define LTQ_SPI_WHBSTATE_SETTE BIT(12) /* Set transmit error flag */
104#define LTQ_SPI_WHBSTATE_CLRTUE BIT(11) /* Clear transmit underflow error flag */
105#define LTQ_SPI_WHBSTATE_CLRAE BIT(10) /* Clear abort error flag */
106#define LTQ_SPI_WHBSTATE_CLRRE BIT(9) /* Clear receive error flag */
107#define LTQ_SPI_WHBSTATE_CLRTE BIT(8) /* Clear transmit error flag */
108#define LTQ_SPI_WHBSTATE_SETME BIT(7) /* Set mode error flag */
109#define LTQ_SPI_WHBSTATE_CLRME BIT(6) /* Clear mode error flag */
110#define LTQ_SPI_WHBSTATE_SETRUE BIT(5) /* Set receive underflow error flag */
111#define LTQ_SPI_WHBSTATE_CLRRUE BIT(4) /* Clear receive underflow error flag */
112#define LTQ_SPI_WHBSTATE_SETMS BIT(3) /* Set master select bit */
113#define LTQ_SPI_WHBSTATE_CLRMS BIT(2) /* Clear master select bit */
114#define LTQ_SPI_WHBSTATE_SETEN BIT(1) /* Set enable bit (operational mode) */
115#define LTQ_SPI_WHBSTATE_CLREN BIT(0) /* Clear enable bit (config mode */
116#define LTQ_SPI_WHBSTATE_CLR_ERRORS (LTQ_SPI_WHBSTATE_CLRRUE | \
117 LTQ_SPI_WHBSTATE_CLRME | \
118 LTQ_SPI_WHBSTATE_CLRTE | \
119 LTQ_SPI_WHBSTATE_CLRRE | \
120 LTQ_SPI_WHBSTATE_CLRAE | \
121 LTQ_SPI_WHBSTATE_CLRTUE)
122
123#define LTQ_SPI_RXFCON_RXFITL_S 8 /* FIFO interrupt trigger level */
124#define LTQ_SPI_RXFCON_RXFLU BIT(1) /* FIFO flush */
125#define LTQ_SPI_RXFCON_RXFEN BIT(0) /* FIFO enable */
126
127#define LTQ_SPI_TXFCON_TXFITL_S 8 /* FIFO interrupt trigger level */
128#define LTQ_SPI_TXFCON_TXFLU BIT(1) /* FIFO flush */
129#define LTQ_SPI_TXFCON_TXFEN BIT(0) /* FIFO enable */
130
131#define LTQ_SPI_FSTAT_RXFFL_S 0
132#define LTQ_SPI_FSTAT_TXFFL_S 8
133
134#define LTQ_SPI_GPOCON_ISCSBN_S 8
135#define LTQ_SPI_GPOCON_INVOUTN_S 0
136
137#define LTQ_SPI_FGPO_SETOUTN_S 8
138#define LTQ_SPI_FGPO_CLROUTN_S 0
139
140#define LTQ_SPI_RXREQ_RXCNT_M 0xFFFF /* Receive count value */
141#define LTQ_SPI_RXCNT_TODO_M 0xFFFF /* Recevie to-do value */
142
143#define LTQ_SPI_IRNEN_TFI BIT(4) /* TX finished interrupt */
144#define LTQ_SPI_IRNEN_F BIT(3) /* Frame end interrupt request */
145#define LTQ_SPI_IRNEN_E BIT(2) /* Error end interrupt request */
146#define LTQ_SPI_IRNEN_T_XWAY BIT(1) /* Transmit end interrupt request */
147#define LTQ_SPI_IRNEN_R_XWAY BIT(0) /* Receive end interrupt request */
148#define LTQ_SPI_IRNEN_R_XRX BIT(1) /* Transmit end interrupt request */
149#define LTQ_SPI_IRNEN_T_XRX BIT(0) /* Receive end interrupt request */
150#define LTQ_SPI_IRNEN_ALL 0x1F
151
152struct lantiq_ssc_spi;
153
154struct lantiq_ssc_hwcfg {
155 int (*cfg_irq)(struct platform_device *pdev, struct lantiq_ssc_spi *spi);
156 unsigned int irnen_r;
157 unsigned int irnen_t;
158 unsigned int irncr;
159 unsigned int irnicr;
160 bool irq_ack;
161 u32 fifo_size_mask;
162};
163
164struct lantiq_ssc_spi {
165 struct spi_master *master;
166 struct device *dev;
167 void __iomem *regbase;
168 struct clk *spi_clk;
169 struct clk *fpi_clk;
170 const struct lantiq_ssc_hwcfg *hwcfg;
171
172 spinlock_t lock;
173 struct workqueue_struct *wq;
174 struct work_struct work;
175
176 const u8 *tx;
177 u8 *rx;
178 unsigned int tx_todo;
179 unsigned int rx_todo;
180 unsigned int bits_per_word;
181 unsigned int speed_hz;
182 unsigned int tx_fifo_size;
183 unsigned int rx_fifo_size;
184 unsigned int base_cs;
185 unsigned int fdx_tx_level;
186};
187
188static u32 lantiq_ssc_readl(const struct lantiq_ssc_spi *spi, u32 reg)
189{
190 return __raw_readl(spi->regbase + reg);
191}
192
193static void lantiq_ssc_writel(const struct lantiq_ssc_spi *spi, u32 val,
194 u32 reg)
195{
196 __raw_writel(val, spi->regbase + reg);
197}
198
199static void lantiq_ssc_maskl(const struct lantiq_ssc_spi *spi, u32 clr,
200 u32 set, u32 reg)
201{
202 u32 val = __raw_readl(spi->regbase + reg);
203
204 val &= ~clr;
205 val |= set;
206 __raw_writel(val, spi->regbase + reg);
207}
208
209static unsigned int tx_fifo_level(const struct lantiq_ssc_spi *spi)
210{
211 const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg;
212 u32 fstat = lantiq_ssc_readl(spi, LTQ_SPI_FSTAT);
213
214 return (fstat >> LTQ_SPI_FSTAT_TXFFL_S) & hwcfg->fifo_size_mask;
215}
216
217static unsigned int rx_fifo_level(const struct lantiq_ssc_spi *spi)
218{
219 const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg;
220 u32 fstat = lantiq_ssc_readl(spi, LTQ_SPI_FSTAT);
221
222 return (fstat >> LTQ_SPI_FSTAT_RXFFL_S) & hwcfg->fifo_size_mask;
223}
224
225static unsigned int tx_fifo_free(const struct lantiq_ssc_spi *spi)
226{
227 return spi->tx_fifo_size - tx_fifo_level(spi);
228}
229
230static void rx_fifo_reset(const struct lantiq_ssc_spi *spi)
231{
232 u32 val = spi->rx_fifo_size << LTQ_SPI_RXFCON_RXFITL_S;
233
234 val |= LTQ_SPI_RXFCON_RXFEN | LTQ_SPI_RXFCON_RXFLU;
235 lantiq_ssc_writel(spi, val, LTQ_SPI_RXFCON);
236}
237
238static void tx_fifo_reset(const struct lantiq_ssc_spi *spi)
239{
240 u32 val = 1 << LTQ_SPI_TXFCON_TXFITL_S;
241
242 val |= LTQ_SPI_TXFCON_TXFEN | LTQ_SPI_TXFCON_TXFLU;
243 lantiq_ssc_writel(spi, val, LTQ_SPI_TXFCON);
244}
245
246static void rx_fifo_flush(const struct lantiq_ssc_spi *spi)
247{
248 lantiq_ssc_maskl(spi, 0, LTQ_SPI_RXFCON_RXFLU, LTQ_SPI_RXFCON);
249}
250
251static void tx_fifo_flush(const struct lantiq_ssc_spi *spi)
252{
253 lantiq_ssc_maskl(spi, 0, LTQ_SPI_TXFCON_TXFLU, LTQ_SPI_TXFCON);
254}
255
256static void hw_enter_config_mode(const struct lantiq_ssc_spi *spi)
257{
258 lantiq_ssc_writel(spi, LTQ_SPI_WHBSTATE_CLREN, LTQ_SPI_WHBSTATE);
259}
260
261static void hw_enter_active_mode(const struct lantiq_ssc_spi *spi)
262{
263 lantiq_ssc_writel(spi, LTQ_SPI_WHBSTATE_SETEN, LTQ_SPI_WHBSTATE);
264}
265
266static void hw_setup_speed_hz(const struct lantiq_ssc_spi *spi,
267 unsigned int max_speed_hz)
268{
269 u32 spi_clk, brt;
270
271 /*
272 * SPI module clock is derived from FPI bus clock dependent on
273 * divider value in CLC.RMS which is always set to 1.
274 *
275 * f_SPI
276 * baudrate = --------------
277 * 2 * (BR + 1)
278 */
279 spi_clk = clk_get_rate(spi->fpi_clk) / 2;
280
281 if (max_speed_hz > spi_clk)
282 brt = 0;
283 else
284 brt = spi_clk / max_speed_hz - 1;
285
286 if (brt > 0xFFFF)
287 brt = 0xFFFF;
288
289 dev_dbg(spi->dev, "spi_clk %u, max_speed_hz %u, brt %u\n",
290 spi_clk, max_speed_hz, brt);
291
292 lantiq_ssc_writel(spi, brt, LTQ_SPI_BRT);
293}
294
295static void hw_setup_bits_per_word(const struct lantiq_ssc_spi *spi,
296 unsigned int bits_per_word)
297{
298 u32 bm;
299
300 /* CON.BM value = bits_per_word - 1 */
301 bm = (bits_per_word - 1) << LTQ_SPI_CON_BM_S;
302
303 lantiq_ssc_maskl(spi, LTQ_SPI_CON_BM_M, bm, LTQ_SPI_CON);
304}
305
306static void hw_setup_clock_mode(const struct lantiq_ssc_spi *spi,
307 unsigned int mode)
308{
309 u32 con_set = 0, con_clr = 0;
310
311 /*
312 * SPI mode mapping in CON register:
313 * Mode CPOL CPHA CON.PO CON.PH
314 * 0 0 0 0 1
315 * 1 0 1 0 0
316 * 2 1 0 1 1
317 * 3 1 1 1 0
318 */
319 if (mode & SPI_CPHA)
320 con_clr |= LTQ_SPI_CON_PH;
321 else
322 con_set |= LTQ_SPI_CON_PH;
323
324 if (mode & SPI_CPOL)
325 con_set |= LTQ_SPI_CON_PO | LTQ_SPI_CON_IDLE;
326 else
327 con_clr |= LTQ_SPI_CON_PO | LTQ_SPI_CON_IDLE;
328
329 /* Set heading control */
330 if (mode & SPI_LSB_FIRST)
331 con_clr |= LTQ_SPI_CON_HB;
332 else
333 con_set |= LTQ_SPI_CON_HB;
334
335 /* Set loopback mode */
336 if (mode & SPI_LOOP)
337 con_set |= LTQ_SPI_CON_LB;
338 else
339 con_clr |= LTQ_SPI_CON_LB;
340
341 lantiq_ssc_maskl(spi, con_clr, con_set, LTQ_SPI_CON);
342}
343
344static void lantiq_ssc_hw_init(const struct lantiq_ssc_spi *spi)
345{
346 const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg;
347
348 /*
349 * Set clock divider for run mode to 1 to
350 * run at same frequency as FPI bus
351 */
352 lantiq_ssc_writel(spi, 1 << LTQ_SPI_CLC_RMC_S, LTQ_SPI_CLC);
353
354 /* Put controller into config mode */
355 hw_enter_config_mode(spi);
356
357 /* Clear error flags */
358 lantiq_ssc_maskl(spi, 0, LTQ_SPI_WHBSTATE_CLR_ERRORS, LTQ_SPI_WHBSTATE);
359
360 /* Enable error checking, disable TX/RX */
361 lantiq_ssc_writel(spi, LTQ_SPI_CON_RUEN | LTQ_SPI_CON_AEN |
362 LTQ_SPI_CON_TEN | LTQ_SPI_CON_REN | LTQ_SPI_CON_TXOFF |
363 LTQ_SPI_CON_RXOFF, LTQ_SPI_CON);
364
365 /* Setup default SPI mode */
366 hw_setup_bits_per_word(spi, spi->bits_per_word);
367 hw_setup_clock_mode(spi, SPI_MODE_0);
368
369 /* Enable master mode and clear error flags */
370 lantiq_ssc_writel(spi, LTQ_SPI_WHBSTATE_SETMS |
371 LTQ_SPI_WHBSTATE_CLR_ERRORS,
372 LTQ_SPI_WHBSTATE);
373
374 /* Reset GPIO/CS registers */
375 lantiq_ssc_writel(spi, 0, LTQ_SPI_GPOCON);
376 lantiq_ssc_writel(spi, 0xFF00, LTQ_SPI_FPGO);
377
378 /* Enable and flush FIFOs */
379 rx_fifo_reset(spi);
380 tx_fifo_reset(spi);
381
382 /* Enable interrupts */
383 lantiq_ssc_writel(spi, hwcfg->irnen_t | hwcfg->irnen_r |
384 LTQ_SPI_IRNEN_E, LTQ_SPI_IRNEN);
385}
386
387static int lantiq_ssc_setup(struct spi_device *spidev)
388{
389 struct spi_master *master = spidev->master;
390 struct lantiq_ssc_spi *spi = spi_master_get_devdata(master);
391 unsigned int cs = spidev->chip_select;
392 u32 gpocon;
393
394 /* GPIOs are used for CS */
395 if (spidev->cs_gpiod)
396 return 0;
397
398 dev_dbg(spi->dev, "using internal chipselect %u\n", cs);
399
400 if (cs < spi->base_cs) {
401 dev_err(spi->dev,
402 "chipselect %i too small (min %i)\n", cs, spi->base_cs);
403 return -EINVAL;
404 }
405
406 /* set GPO pin to CS mode */
407 gpocon = 1 << ((cs - spi->base_cs) + LTQ_SPI_GPOCON_ISCSBN_S);
408
409 /* invert GPO pin */
410 if (spidev->mode & SPI_CS_HIGH)
411 gpocon |= 1 << (cs - spi->base_cs);
412
413 lantiq_ssc_maskl(spi, 0, gpocon, LTQ_SPI_GPOCON);
414
415 return 0;
416}
417
418static int lantiq_ssc_prepare_message(struct spi_master *master,
419 struct spi_message *message)
420{
421 struct lantiq_ssc_spi *spi = spi_master_get_devdata(master);
422
423 hw_enter_config_mode(spi);
424 hw_setup_clock_mode(spi, message->spi->mode);
425 hw_enter_active_mode(spi);
426
427 return 0;
428}
429
430static void hw_setup_transfer(struct lantiq_ssc_spi *spi,
431 struct spi_device *spidev, struct spi_transfer *t)
432{
433 unsigned int speed_hz = t->speed_hz;
434 unsigned int bits_per_word = t->bits_per_word;
435 u32 con;
436
437 if (bits_per_word != spi->bits_per_word ||
438 speed_hz != spi->speed_hz) {
439 hw_enter_config_mode(spi);
440 hw_setup_speed_hz(spi, speed_hz);
441 hw_setup_bits_per_word(spi, bits_per_word);
442 hw_enter_active_mode(spi);
443
444 spi->speed_hz = speed_hz;
445 spi->bits_per_word = bits_per_word;
446 }
447
448 /* Configure transmitter and receiver */
449 con = lantiq_ssc_readl(spi, LTQ_SPI_CON);
450 if (t->tx_buf)
451 con &= ~LTQ_SPI_CON_TXOFF;
452 else
453 con |= LTQ_SPI_CON_TXOFF;
454
455 if (t->rx_buf)
456 con &= ~LTQ_SPI_CON_RXOFF;
457 else
458 con |= LTQ_SPI_CON_RXOFF;
459
460 lantiq_ssc_writel(spi, con, LTQ_SPI_CON);
461}
462
463static int lantiq_ssc_unprepare_message(struct spi_master *master,
464 struct spi_message *message)
465{
466 struct lantiq_ssc_spi *spi = spi_master_get_devdata(master);
467
468 flush_workqueue(spi->wq);
469
470 /* Disable transmitter and receiver while idle */
471 lantiq_ssc_maskl(spi, 0, LTQ_SPI_CON_TXOFF | LTQ_SPI_CON_RXOFF,
472 LTQ_SPI_CON);
473
474 return 0;
475}
476
477static void tx_fifo_write(struct lantiq_ssc_spi *spi)
478{
479 const u8 *tx8;
480 const u16 *tx16;
481 const u32 *tx32;
482 u32 data;
483 unsigned int tx_free = tx_fifo_free(spi);
484
485 spi->fdx_tx_level = 0;
486 while (spi->tx_todo && tx_free) {
487 switch (spi->bits_per_word) {
488 case 2 ... 8:
489 tx8 = spi->tx;
490 data = *tx8;
491 spi->tx_todo--;
492 spi->tx++;
493 break;
494 case 16:
495 tx16 = (u16 *) spi->tx;
496 data = *tx16;
497 spi->tx_todo -= 2;
498 spi->tx += 2;
499 break;
500 case 32:
501 tx32 = (u32 *) spi->tx;
502 data = *tx32;
503 spi->tx_todo -= 4;
504 spi->tx += 4;
505 break;
506 default:
507 WARN_ON(1);
508 data = 0;
509 break;
510 }
511
512 lantiq_ssc_writel(spi, data, LTQ_SPI_TB);
513 tx_free--;
514 spi->fdx_tx_level++;
515 }
516}
517
518static void rx_fifo_read_full_duplex(struct lantiq_ssc_spi *spi)
519{
520 u8 *rx8;
521 u16 *rx16;
522 u32 *rx32;
523 u32 data;
524 unsigned int rx_fill = rx_fifo_level(spi);
525
526 /*
527 * Wait until all expected data to be shifted in.
528 * Otherwise, rx overrun may occur.
529 */
530 while (rx_fill != spi->fdx_tx_level)
531 rx_fill = rx_fifo_level(spi);
532
533 while (rx_fill) {
534 data = lantiq_ssc_readl(spi, LTQ_SPI_RB);
535
536 switch (spi->bits_per_word) {
537 case 2 ... 8:
538 rx8 = spi->rx;
539 *rx8 = data;
540 spi->rx_todo--;
541 spi->rx++;
542 break;
543 case 16:
544 rx16 = (u16 *) spi->rx;
545 *rx16 = data;
546 spi->rx_todo -= 2;
547 spi->rx += 2;
548 break;
549 case 32:
550 rx32 = (u32 *) spi->rx;
551 *rx32 = data;
552 spi->rx_todo -= 4;
553 spi->rx += 4;
554 break;
555 default:
556 WARN_ON(1);
557 break;
558 }
559
560 rx_fill--;
561 }
562}
563
564static void rx_fifo_read_half_duplex(struct lantiq_ssc_spi *spi)
565{
566 u32 data, *rx32;
567 u8 *rx8;
568 unsigned int rxbv, shift;
569 unsigned int rx_fill = rx_fifo_level(spi);
570
571 /*
572 * In RX-only mode the bits per word value is ignored by HW. A value
573 * of 32 is used instead. Thus all 4 bytes per FIFO must be read.
574 * If remaining RX bytes are less than 4, the FIFO must be read
575 * differently. The amount of received and valid bytes is indicated
576 * by STAT.RXBV register value.
577 */
578 while (rx_fill) {
579 if (spi->rx_todo < 4) {
580 rxbv = (lantiq_ssc_readl(spi, LTQ_SPI_STAT) &
581 LTQ_SPI_STAT_RXBV_M) >> LTQ_SPI_STAT_RXBV_S;
582 data = lantiq_ssc_readl(spi, LTQ_SPI_RB);
583
584 shift = (rxbv - 1) * 8;
585 rx8 = spi->rx;
586
587 while (rxbv) {
588 *rx8++ = (data >> shift) & 0xFF;
589 rxbv--;
590 shift -= 8;
591 spi->rx_todo--;
592 spi->rx++;
593 }
594 } else {
595 data = lantiq_ssc_readl(spi, LTQ_SPI_RB);
596 rx32 = (u32 *) spi->rx;
597
598 *rx32++ = data;
599 spi->rx_todo -= 4;
600 spi->rx += 4;
601 }
602 rx_fill--;
603 }
604}
605
606static void rx_request(struct lantiq_ssc_spi *spi)
607{
608 unsigned int rxreq, rxreq_max;
609
610 /*
611 * To avoid receive overflows at high clocks it is better to request
612 * only the amount of bytes that fits into all FIFOs. This value
613 * depends on the FIFO size implemented in hardware.
614 */
615 rxreq = spi->rx_todo;
616 rxreq_max = spi->rx_fifo_size * 4;
617 if (rxreq > rxreq_max)
618 rxreq = rxreq_max;
619
620 lantiq_ssc_writel(spi, rxreq, LTQ_SPI_RXREQ);
621}
622
623static irqreturn_t lantiq_ssc_xmit_interrupt(int irq, void *data)
624{
625 struct lantiq_ssc_spi *spi = data;
626 const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg;
627 u32 val = lantiq_ssc_readl(spi, hwcfg->irncr);
628
629 spin_lock(&spi->lock);
630 if (hwcfg->irq_ack)
631 lantiq_ssc_writel(spi, val, hwcfg->irncr);
632
633 if (spi->tx) {
634 if (spi->rx && spi->rx_todo)
635 rx_fifo_read_full_duplex(spi);
636
637 if (spi->tx_todo)
638 tx_fifo_write(spi);
639 else if (!tx_fifo_level(spi))
640 goto completed;
641 } else if (spi->rx) {
642 if (spi->rx_todo) {
643 rx_fifo_read_half_duplex(spi);
644
645 if (spi->rx_todo)
646 rx_request(spi);
647 else
648 goto completed;
649 } else {
650 goto completed;
651 }
652 }
653
654 spin_unlock(&spi->lock);
655 return IRQ_HANDLED;
656
657completed:
658 queue_work(spi->wq, &spi->work);
659 spin_unlock(&spi->lock);
660
661 return IRQ_HANDLED;
662}
663
664static irqreturn_t lantiq_ssc_err_interrupt(int irq, void *data)
665{
666 struct lantiq_ssc_spi *spi = data;
667 const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg;
668 u32 stat = lantiq_ssc_readl(spi, LTQ_SPI_STAT);
669 u32 val = lantiq_ssc_readl(spi, hwcfg->irncr);
670
671 if (!(stat & LTQ_SPI_STAT_ERRORS))
672 return IRQ_NONE;
673
674 spin_lock(&spi->lock);
675 if (hwcfg->irq_ack)
676 lantiq_ssc_writel(spi, val, hwcfg->irncr);
677
678 if (stat & LTQ_SPI_STAT_RUE)
679 dev_err(spi->dev, "receive underflow error\n");
680 if (stat & LTQ_SPI_STAT_TUE)
681 dev_err(spi->dev, "transmit underflow error\n");
682 if (stat & LTQ_SPI_STAT_AE)
683 dev_err(spi->dev, "abort error\n");
684 if (stat & LTQ_SPI_STAT_RE)
685 dev_err(spi->dev, "receive overflow error\n");
686 if (stat & LTQ_SPI_STAT_TE)
687 dev_err(spi->dev, "transmit overflow error\n");
688 if (stat & LTQ_SPI_STAT_ME)
689 dev_err(spi->dev, "mode error\n");
690
691 /* Clear error flags */
692 lantiq_ssc_maskl(spi, 0, LTQ_SPI_WHBSTATE_CLR_ERRORS, LTQ_SPI_WHBSTATE);
693
694 /* set bad status so it can be retried */
695 if (spi->master->cur_msg)
696 spi->master->cur_msg->status = -EIO;
697 queue_work(spi->wq, &spi->work);
698 spin_unlock(&spi->lock);
699
700 return IRQ_HANDLED;
701}
702
703static irqreturn_t intel_lgm_ssc_isr(int irq, void *data)
704{
705 struct lantiq_ssc_spi *spi = data;
706 const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg;
707 u32 val = lantiq_ssc_readl(spi, hwcfg->irncr);
708
709 if (!(val & LTQ_SPI_IRNEN_ALL))
710 return IRQ_NONE;
711
712 if (val & LTQ_SPI_IRNEN_E)
713 return lantiq_ssc_err_interrupt(irq, data);
714
715 if ((val & hwcfg->irnen_t) || (val & hwcfg->irnen_r))
716 return lantiq_ssc_xmit_interrupt(irq, data);
717
718 return IRQ_HANDLED;
719}
720
721static int transfer_start(struct lantiq_ssc_spi *spi, struct spi_device *spidev,
722 struct spi_transfer *t)
723{
724 unsigned long flags;
725
726 spin_lock_irqsave(&spi->lock, flags);
727
728 spi->tx = t->tx_buf;
729 spi->rx = t->rx_buf;
730
731 if (t->tx_buf) {
732 spi->tx_todo = t->len;
733
734 /* initially fill TX FIFO */
735 tx_fifo_write(spi);
736 }
737
738 if (spi->rx) {
739 spi->rx_todo = t->len;
740
741 /* start shift clock in RX-only mode */
742 if (!spi->tx)
743 rx_request(spi);
744 }
745
746 spin_unlock_irqrestore(&spi->lock, flags);
747
748 return t->len;
749}
750
751/*
752 * The driver only gets an interrupt when the FIFO is empty, but there
753 * is an additional shift register from which the data is written to
754 * the wire. We get the last interrupt when the controller starts to
755 * write the last word to the wire, not when it is finished. Do busy
756 * waiting till it finishes.
757 */
758static void lantiq_ssc_bussy_work(struct work_struct *work)
759{
760 struct lantiq_ssc_spi *spi;
761 unsigned long long timeout = 8LL * 1000LL;
762 unsigned long end;
763
764 spi = container_of(work, typeof(*spi), work);
765
766 do_div(timeout, spi->speed_hz);
767 timeout += timeout + 100; /* some tolerance */
768
769 end = jiffies + msecs_to_jiffies(timeout);
770 do {
771 u32 stat = lantiq_ssc_readl(spi, LTQ_SPI_STAT);
772
773 if (!(stat & LTQ_SPI_STAT_BSY)) {
774 spi_finalize_current_transfer(spi->master);
775 return;
776 }
777
778 cond_resched();
779 } while (!time_after_eq(jiffies, end));
780
781 if (spi->master->cur_msg)
782 spi->master->cur_msg->status = -EIO;
783 spi_finalize_current_transfer(spi->master);
784}
785
786static void lantiq_ssc_handle_err(struct spi_master *master,
787 struct spi_message *message)
788{
789 struct lantiq_ssc_spi *spi = spi_master_get_devdata(master);
790
791 /* flush FIFOs on timeout */
792 rx_fifo_flush(spi);
793 tx_fifo_flush(spi);
794}
795
796static void lantiq_ssc_set_cs(struct spi_device *spidev, bool enable)
797{
798 struct lantiq_ssc_spi *spi = spi_master_get_devdata(spidev->master);
799 unsigned int cs = spidev->chip_select;
800 u32 fgpo;
801
802 if (!!(spidev->mode & SPI_CS_HIGH) == enable)
803 fgpo = (1 << (cs - spi->base_cs));
804 else
805 fgpo = (1 << (cs - spi->base_cs + LTQ_SPI_FGPO_SETOUTN_S));
806
807 lantiq_ssc_writel(spi, fgpo, LTQ_SPI_FPGO);
808}
809
810static int lantiq_ssc_transfer_one(struct spi_master *master,
811 struct spi_device *spidev,
812 struct spi_transfer *t)
813{
814 struct lantiq_ssc_spi *spi = spi_master_get_devdata(master);
815
816 hw_setup_transfer(spi, spidev, t);
817
818 return transfer_start(spi, spidev, t);
819}
820
821static int intel_lgm_cfg_irq(struct platform_device *pdev, struct lantiq_ssc_spi *spi)
822{
823 int irq;
824
825 irq = platform_get_irq(pdev, 0);
826 if (irq < 0)
827 return irq;
828
829 return devm_request_irq(&pdev->dev, irq, intel_lgm_ssc_isr, 0, "spi", spi);
830}
831
832static int lantiq_cfg_irq(struct platform_device *pdev, struct lantiq_ssc_spi *spi)
833{
834 int irq, err;
835
836 irq = platform_get_irq_byname(pdev, LTQ_SPI_RX_IRQ_NAME);
837 if (irq < 0)
838 return irq;
839
840 err = devm_request_irq(&pdev->dev, irq, lantiq_ssc_xmit_interrupt,
841 0, LTQ_SPI_RX_IRQ_NAME, spi);
842 if (err)
843 return err;
844
845 irq = platform_get_irq_byname(pdev, LTQ_SPI_TX_IRQ_NAME);
846 if (irq < 0)
847 return irq;
848
849 err = devm_request_irq(&pdev->dev, irq, lantiq_ssc_xmit_interrupt,
850 0, LTQ_SPI_TX_IRQ_NAME, spi);
851
852 if (err)
853 return err;
854
855 irq = platform_get_irq_byname(pdev, LTQ_SPI_ERR_IRQ_NAME);
856 if (irq < 0)
857 return irq;
858
859 err = devm_request_irq(&pdev->dev, irq, lantiq_ssc_err_interrupt,
860 0, LTQ_SPI_ERR_IRQ_NAME, spi);
861 return err;
862}
863
864static const struct lantiq_ssc_hwcfg lantiq_ssc_xway = {
865 .cfg_irq = lantiq_cfg_irq,
866 .irnen_r = LTQ_SPI_IRNEN_R_XWAY,
867 .irnen_t = LTQ_SPI_IRNEN_T_XWAY,
868 .irnicr = 0xF8,
869 .irncr = 0xFC,
870 .fifo_size_mask = GENMASK(5, 0),
871 .irq_ack = false,
872};
873
874static const struct lantiq_ssc_hwcfg lantiq_ssc_xrx = {
875 .cfg_irq = lantiq_cfg_irq,
876 .irnen_r = LTQ_SPI_IRNEN_R_XRX,
877 .irnen_t = LTQ_SPI_IRNEN_T_XRX,
878 .irnicr = 0xF8,
879 .irncr = 0xFC,
880 .fifo_size_mask = GENMASK(5, 0),
881 .irq_ack = false,
882};
883
884static const struct lantiq_ssc_hwcfg intel_ssc_lgm = {
885 .cfg_irq = intel_lgm_cfg_irq,
886 .irnen_r = LTQ_SPI_IRNEN_R_XRX,
887 .irnen_t = LTQ_SPI_IRNEN_T_XRX,
888 .irnicr = 0xFC,
889 .irncr = 0xF8,
890 .fifo_size_mask = GENMASK(7, 0),
891 .irq_ack = true,
892};
893
894static const struct of_device_id lantiq_ssc_match[] = {
895 { .compatible = "lantiq,ase-spi", .data = &lantiq_ssc_xway, },
896 { .compatible = "lantiq,falcon-spi", .data = &lantiq_ssc_xrx, },
897 { .compatible = "lantiq,xrx100-spi", .data = &lantiq_ssc_xrx, },
898 { .compatible = "intel,lgm-spi", .data = &intel_ssc_lgm, },
899 {},
900};
901MODULE_DEVICE_TABLE(of, lantiq_ssc_match);
902
903static int lantiq_ssc_probe(struct platform_device *pdev)
904{
905 struct device *dev = &pdev->dev;
906 struct spi_master *master;
907 struct lantiq_ssc_spi *spi;
908 const struct lantiq_ssc_hwcfg *hwcfg;
909 u32 id, supports_dma, revision;
910 unsigned int num_cs;
911 int err;
912
913 hwcfg = of_device_get_match_data(dev);
914
915 master = spi_alloc_master(dev, sizeof(struct lantiq_ssc_spi));
916 if (!master)
917 return -ENOMEM;
918
919 spi = spi_master_get_devdata(master);
920 spi->master = master;
921 spi->dev = dev;
922 spi->hwcfg = hwcfg;
923 platform_set_drvdata(pdev, spi);
924 spi->regbase = devm_platform_ioremap_resource(pdev, 0);
925 if (IS_ERR(spi->regbase)) {
926 err = PTR_ERR(spi->regbase);
927 goto err_master_put;
928 }
929
930 err = hwcfg->cfg_irq(pdev, spi);
931 if (err)
932 goto err_master_put;
933
934 spi->spi_clk = devm_clk_get(dev, "gate");
935 if (IS_ERR(spi->spi_clk)) {
936 err = PTR_ERR(spi->spi_clk);
937 goto err_master_put;
938 }
939 err = clk_prepare_enable(spi->spi_clk);
940 if (err)
941 goto err_master_put;
942
943 /*
944 * Use the old clk_get_fpi() function on Lantiq platform, till it
945 * supports common clk.
946 */
947#if defined(CONFIG_LANTIQ) && !defined(CONFIG_COMMON_CLK)
948 spi->fpi_clk = clk_get_fpi();
949#else
950 spi->fpi_clk = clk_get(dev, "freq");
951#endif
952 if (IS_ERR(spi->fpi_clk)) {
953 err = PTR_ERR(spi->fpi_clk);
954 goto err_clk_disable;
955 }
956
957 num_cs = 8;
958 of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs);
959
960 spi->base_cs = 1;
961 of_property_read_u32(pdev->dev.of_node, "base-cs", &spi->base_cs);
962
963 spin_lock_init(&spi->lock);
964 spi->bits_per_word = 8;
965 spi->speed_hz = 0;
966
967 master->dev.of_node = pdev->dev.of_node;
968 master->num_chipselect = num_cs;
969 master->use_gpio_descriptors = true;
970 master->setup = lantiq_ssc_setup;
971 master->set_cs = lantiq_ssc_set_cs;
972 master->handle_err = lantiq_ssc_handle_err;
973 master->prepare_message = lantiq_ssc_prepare_message;
974 master->unprepare_message = lantiq_ssc_unprepare_message;
975 master->transfer_one = lantiq_ssc_transfer_one;
976 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_CS_HIGH |
977 SPI_LOOP;
978 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 8) |
979 SPI_BPW_MASK(16) | SPI_BPW_MASK(32);
980
981 spi->wq = alloc_ordered_workqueue(dev_name(dev), WQ_MEM_RECLAIM);
982 if (!spi->wq) {
983 err = -ENOMEM;
984 goto err_clk_put;
985 }
986 INIT_WORK(&spi->work, lantiq_ssc_bussy_work);
987
988 id = lantiq_ssc_readl(spi, LTQ_SPI_ID);
989 spi->tx_fifo_size = (id >> LTQ_SPI_ID_TXFS_S) & hwcfg->fifo_size_mask;
990 spi->rx_fifo_size = (id >> LTQ_SPI_ID_RXFS_S) & hwcfg->fifo_size_mask;
991 supports_dma = (id & LTQ_SPI_ID_CFG_M) >> LTQ_SPI_ID_CFG_S;
992 revision = id & LTQ_SPI_ID_REV_M;
993
994 lantiq_ssc_hw_init(spi);
995
996 dev_info(dev,
997 "Lantiq SSC SPI controller (Rev %i, TXFS %u, RXFS %u, DMA %u)\n",
998 revision, spi->tx_fifo_size, spi->rx_fifo_size, supports_dma);
999
1000 err = devm_spi_register_master(dev, master);
1001 if (err) {
1002 dev_err(dev, "failed to register spi_master\n");
1003 goto err_wq_destroy;
1004 }
1005
1006 return 0;
1007
1008err_wq_destroy:
1009 destroy_workqueue(spi->wq);
1010err_clk_put:
1011 clk_put(spi->fpi_clk);
1012err_clk_disable:
1013 clk_disable_unprepare(spi->spi_clk);
1014err_master_put:
1015 spi_master_put(master);
1016
1017 return err;
1018}
1019
1020static int lantiq_ssc_remove(struct platform_device *pdev)
1021{
1022 struct lantiq_ssc_spi *spi = platform_get_drvdata(pdev);
1023
1024 lantiq_ssc_writel(spi, 0, LTQ_SPI_IRNEN);
1025 lantiq_ssc_writel(spi, 0, LTQ_SPI_CLC);
1026 rx_fifo_flush(spi);
1027 tx_fifo_flush(spi);
1028 hw_enter_config_mode(spi);
1029
1030 destroy_workqueue(spi->wq);
1031 clk_disable_unprepare(spi->spi_clk);
1032 clk_put(spi->fpi_clk);
1033
1034 return 0;
1035}
1036
1037static struct platform_driver lantiq_ssc_driver = {
1038 .probe = lantiq_ssc_probe,
1039 .remove = lantiq_ssc_remove,
1040 .driver = {
1041 .name = "spi-lantiq-ssc",
1042 .of_match_table = lantiq_ssc_match,
1043 },
1044};
1045module_platform_driver(lantiq_ssc_driver);
1046
1047MODULE_DESCRIPTION("Lantiq SSC SPI controller driver");
1048MODULE_AUTHOR("Daniel Schwierzeck <daniel.schwierzeck@gmail.com>");
1049MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
1050MODULE_LICENSE("GPL");
1051MODULE_ALIAS("platform:spi-lantiq-ssc");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2011-2015 Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
4 * Copyright (C) 2016 Hauke Mehrtens <hauke@hauke-m.de>
5 */
6
7#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/of_device.h>
10#include <linux/clk.h>
11#include <linux/io.h>
12#include <linux/delay.h>
13#include <linux/interrupt.h>
14#include <linux/sched.h>
15#include <linux/completion.h>
16#include <linux/spinlock.h>
17#include <linux/err.h>
18#include <linux/gpio.h>
19#include <linux/pm_runtime.h>
20#include <linux/spi/spi.h>
21
22#ifdef CONFIG_LANTIQ
23#include <lantiq_soc.h>
24#endif
25
26#define LTQ_SPI_RX_IRQ_NAME "spi_rx"
27#define LTQ_SPI_TX_IRQ_NAME "spi_tx"
28#define LTQ_SPI_ERR_IRQ_NAME "spi_err"
29#define LTQ_SPI_FRM_IRQ_NAME "spi_frm"
30
31#define LTQ_SPI_CLC 0x00
32#define LTQ_SPI_PISEL 0x04
33#define LTQ_SPI_ID 0x08
34#define LTQ_SPI_CON 0x10
35#define LTQ_SPI_STAT 0x14
36#define LTQ_SPI_WHBSTATE 0x18
37#define LTQ_SPI_TB 0x20
38#define LTQ_SPI_RB 0x24
39#define LTQ_SPI_RXFCON 0x30
40#define LTQ_SPI_TXFCON 0x34
41#define LTQ_SPI_FSTAT 0x38
42#define LTQ_SPI_BRT 0x40
43#define LTQ_SPI_BRSTAT 0x44
44#define LTQ_SPI_SFCON 0x60
45#define LTQ_SPI_SFSTAT 0x64
46#define LTQ_SPI_GPOCON 0x70
47#define LTQ_SPI_GPOSTAT 0x74
48#define LTQ_SPI_FPGO 0x78
49#define LTQ_SPI_RXREQ 0x80
50#define LTQ_SPI_RXCNT 0x84
51#define LTQ_SPI_DMACON 0xec
52#define LTQ_SPI_IRNEN 0xf4
53#define LTQ_SPI_IRNICR 0xf8
54#define LTQ_SPI_IRNCR 0xfc
55
56#define LTQ_SPI_CLC_SMC_S 16 /* Clock divider for sleep mode */
57#define LTQ_SPI_CLC_SMC_M (0xFF << LTQ_SPI_CLC_SMC_S)
58#define LTQ_SPI_CLC_RMC_S 8 /* Clock divider for normal run mode */
59#define LTQ_SPI_CLC_RMC_M (0xFF << LTQ_SPI_CLC_RMC_S)
60#define LTQ_SPI_CLC_DISS BIT(1) /* Disable status bit */
61#define LTQ_SPI_CLC_DISR BIT(0) /* Disable request bit */
62
63#define LTQ_SPI_ID_TXFS_S 24 /* Implemented TX FIFO size */
64#define LTQ_SPI_ID_TXFS_M (0x3F << LTQ_SPI_ID_TXFS_S)
65#define LTQ_SPI_ID_RXFS_S 16 /* Implemented RX FIFO size */
66#define LTQ_SPI_ID_RXFS_M (0x3F << LTQ_SPI_ID_RXFS_S)
67#define LTQ_SPI_ID_MOD_S 8 /* Module ID */
68#define LTQ_SPI_ID_MOD_M (0xff << LTQ_SPI_ID_MOD_S)
69#define LTQ_SPI_ID_CFG_S 5 /* DMA interface support */
70#define LTQ_SPI_ID_CFG_M (1 << LTQ_SPI_ID_CFG_S)
71#define LTQ_SPI_ID_REV_M 0x1F /* Hardware revision number */
72
73#define LTQ_SPI_CON_BM_S 16 /* Data width selection */
74#define LTQ_SPI_CON_BM_M (0x1F << LTQ_SPI_CON_BM_S)
75#define LTQ_SPI_CON_EM BIT(24) /* Echo mode */
76#define LTQ_SPI_CON_IDLE BIT(23) /* Idle bit value */
77#define LTQ_SPI_CON_ENBV BIT(22) /* Enable byte valid control */
78#define LTQ_SPI_CON_RUEN BIT(12) /* Receive underflow error enable */
79#define LTQ_SPI_CON_TUEN BIT(11) /* Transmit underflow error enable */
80#define LTQ_SPI_CON_AEN BIT(10) /* Abort error enable */
81#define LTQ_SPI_CON_REN BIT(9) /* Receive overflow error enable */
82#define LTQ_SPI_CON_TEN BIT(8) /* Transmit overflow error enable */
83#define LTQ_SPI_CON_LB BIT(7) /* Loopback control */
84#define LTQ_SPI_CON_PO BIT(6) /* Clock polarity control */
85#define LTQ_SPI_CON_PH BIT(5) /* Clock phase control */
86#define LTQ_SPI_CON_HB BIT(4) /* Heading control */
87#define LTQ_SPI_CON_RXOFF BIT(1) /* Switch receiver off */
88#define LTQ_SPI_CON_TXOFF BIT(0) /* Switch transmitter off */
89
90#define LTQ_SPI_STAT_RXBV_S 28
91#define LTQ_SPI_STAT_RXBV_M (0x7 << LTQ_SPI_STAT_RXBV_S)
92#define LTQ_SPI_STAT_BSY BIT(13) /* Busy flag */
93#define LTQ_SPI_STAT_RUE BIT(12) /* Receive underflow error flag */
94#define LTQ_SPI_STAT_TUE BIT(11) /* Transmit underflow error flag */
95#define LTQ_SPI_STAT_AE BIT(10) /* Abort error flag */
96#define LTQ_SPI_STAT_RE BIT(9) /* Receive error flag */
97#define LTQ_SPI_STAT_TE BIT(8) /* Transmit error flag */
98#define LTQ_SPI_STAT_ME BIT(7) /* Mode error flag */
99#define LTQ_SPI_STAT_MS BIT(1) /* Master/slave select bit */
100#define LTQ_SPI_STAT_EN BIT(0) /* Enable bit */
101#define LTQ_SPI_STAT_ERRORS (LTQ_SPI_STAT_ME | LTQ_SPI_STAT_TE | \
102 LTQ_SPI_STAT_RE | LTQ_SPI_STAT_AE | \
103 LTQ_SPI_STAT_TUE | LTQ_SPI_STAT_RUE)
104
105#define LTQ_SPI_WHBSTATE_SETTUE BIT(15) /* Set transmit underflow error flag */
106#define LTQ_SPI_WHBSTATE_SETAE BIT(14) /* Set abort error flag */
107#define LTQ_SPI_WHBSTATE_SETRE BIT(13) /* Set receive error flag */
108#define LTQ_SPI_WHBSTATE_SETTE BIT(12) /* Set transmit error flag */
109#define LTQ_SPI_WHBSTATE_CLRTUE BIT(11) /* Clear transmit underflow error flag */
110#define LTQ_SPI_WHBSTATE_CLRAE BIT(10) /* Clear abort error flag */
111#define LTQ_SPI_WHBSTATE_CLRRE BIT(9) /* Clear receive error flag */
112#define LTQ_SPI_WHBSTATE_CLRTE BIT(8) /* Clear transmit error flag */
113#define LTQ_SPI_WHBSTATE_SETME BIT(7) /* Set mode error flag */
114#define LTQ_SPI_WHBSTATE_CLRME BIT(6) /* Clear mode error flag */
115#define LTQ_SPI_WHBSTATE_SETRUE BIT(5) /* Set receive underflow error flag */
116#define LTQ_SPI_WHBSTATE_CLRRUE BIT(4) /* Clear receive underflow error flag */
117#define LTQ_SPI_WHBSTATE_SETMS BIT(3) /* Set master select bit */
118#define LTQ_SPI_WHBSTATE_CLRMS BIT(2) /* Clear master select bit */
119#define LTQ_SPI_WHBSTATE_SETEN BIT(1) /* Set enable bit (operational mode) */
120#define LTQ_SPI_WHBSTATE_CLREN BIT(0) /* Clear enable bit (config mode */
121#define LTQ_SPI_WHBSTATE_CLR_ERRORS (LTQ_SPI_WHBSTATE_CLRRUE | \
122 LTQ_SPI_WHBSTATE_CLRME | \
123 LTQ_SPI_WHBSTATE_CLRTE | \
124 LTQ_SPI_WHBSTATE_CLRRE | \
125 LTQ_SPI_WHBSTATE_CLRAE | \
126 LTQ_SPI_WHBSTATE_CLRTUE)
127
128#define LTQ_SPI_RXFCON_RXFITL_S 8 /* FIFO interrupt trigger level */
129#define LTQ_SPI_RXFCON_RXFITL_M (0x3F << LTQ_SPI_RXFCON_RXFITL_S)
130#define LTQ_SPI_RXFCON_RXFLU BIT(1) /* FIFO flush */
131#define LTQ_SPI_RXFCON_RXFEN BIT(0) /* FIFO enable */
132
133#define LTQ_SPI_TXFCON_TXFITL_S 8 /* FIFO interrupt trigger level */
134#define LTQ_SPI_TXFCON_TXFITL_M (0x3F << LTQ_SPI_TXFCON_TXFITL_S)
135#define LTQ_SPI_TXFCON_TXFLU BIT(1) /* FIFO flush */
136#define LTQ_SPI_TXFCON_TXFEN BIT(0) /* FIFO enable */
137
138#define LTQ_SPI_FSTAT_RXFFL_S 0
139#define LTQ_SPI_FSTAT_RXFFL_M (0x3f << LTQ_SPI_FSTAT_RXFFL_S)
140#define LTQ_SPI_FSTAT_TXFFL_S 8
141#define LTQ_SPI_FSTAT_TXFFL_M (0x3f << LTQ_SPI_FSTAT_TXFFL_S)
142
143#define LTQ_SPI_GPOCON_ISCSBN_S 8
144#define LTQ_SPI_GPOCON_INVOUTN_S 0
145
146#define LTQ_SPI_FGPO_SETOUTN_S 8
147#define LTQ_SPI_FGPO_CLROUTN_S 0
148
149#define LTQ_SPI_RXREQ_RXCNT_M 0xFFFF /* Receive count value */
150#define LTQ_SPI_RXCNT_TODO_M 0xFFFF /* Recevie to-do value */
151
152#define LTQ_SPI_IRNEN_TFI BIT(4) /* TX finished interrupt */
153#define LTQ_SPI_IRNEN_F BIT(3) /* Frame end interrupt request */
154#define LTQ_SPI_IRNEN_E BIT(2) /* Error end interrupt request */
155#define LTQ_SPI_IRNEN_T_XWAY BIT(1) /* Transmit end interrupt request */
156#define LTQ_SPI_IRNEN_R_XWAY BIT(0) /* Receive end interrupt request */
157#define LTQ_SPI_IRNEN_R_XRX BIT(1) /* Transmit end interrupt request */
158#define LTQ_SPI_IRNEN_T_XRX BIT(0) /* Receive end interrupt request */
159#define LTQ_SPI_IRNEN_ALL 0x1F
160
161struct lantiq_ssc_hwcfg {
162 unsigned int irnen_r;
163 unsigned int irnen_t;
164};
165
166struct lantiq_ssc_spi {
167 struct spi_master *master;
168 struct device *dev;
169 void __iomem *regbase;
170 struct clk *spi_clk;
171 struct clk *fpi_clk;
172 const struct lantiq_ssc_hwcfg *hwcfg;
173
174 spinlock_t lock;
175 struct workqueue_struct *wq;
176 struct work_struct work;
177
178 const u8 *tx;
179 u8 *rx;
180 unsigned int tx_todo;
181 unsigned int rx_todo;
182 unsigned int bits_per_word;
183 unsigned int speed_hz;
184 unsigned int tx_fifo_size;
185 unsigned int rx_fifo_size;
186 unsigned int base_cs;
187};
188
189static u32 lantiq_ssc_readl(const struct lantiq_ssc_spi *spi, u32 reg)
190{
191 return __raw_readl(spi->regbase + reg);
192}
193
194static void lantiq_ssc_writel(const struct lantiq_ssc_spi *spi, u32 val,
195 u32 reg)
196{
197 __raw_writel(val, spi->regbase + reg);
198}
199
200static void lantiq_ssc_maskl(const struct lantiq_ssc_spi *spi, u32 clr,
201 u32 set, u32 reg)
202{
203 u32 val = __raw_readl(spi->regbase + reg);
204
205 val &= ~clr;
206 val |= set;
207 __raw_writel(val, spi->regbase + reg);
208}
209
210static unsigned int tx_fifo_level(const struct lantiq_ssc_spi *spi)
211{
212 u32 fstat = lantiq_ssc_readl(spi, LTQ_SPI_FSTAT);
213
214 return (fstat & LTQ_SPI_FSTAT_TXFFL_M) >> LTQ_SPI_FSTAT_TXFFL_S;
215}
216
217static unsigned int rx_fifo_level(const struct lantiq_ssc_spi *spi)
218{
219 u32 fstat = lantiq_ssc_readl(spi, LTQ_SPI_FSTAT);
220
221 return fstat & LTQ_SPI_FSTAT_RXFFL_M;
222}
223
224static unsigned int tx_fifo_free(const struct lantiq_ssc_spi *spi)
225{
226 return spi->tx_fifo_size - tx_fifo_level(spi);
227}
228
229static void rx_fifo_reset(const struct lantiq_ssc_spi *spi)
230{
231 u32 val = spi->rx_fifo_size << LTQ_SPI_RXFCON_RXFITL_S;
232
233 val |= LTQ_SPI_RXFCON_RXFEN | LTQ_SPI_RXFCON_RXFLU;
234 lantiq_ssc_writel(spi, val, LTQ_SPI_RXFCON);
235}
236
237static void tx_fifo_reset(const struct lantiq_ssc_spi *spi)
238{
239 u32 val = 1 << LTQ_SPI_TXFCON_TXFITL_S;
240
241 val |= LTQ_SPI_TXFCON_TXFEN | LTQ_SPI_TXFCON_TXFLU;
242 lantiq_ssc_writel(spi, val, LTQ_SPI_TXFCON);
243}
244
245static void rx_fifo_flush(const struct lantiq_ssc_spi *spi)
246{
247 lantiq_ssc_maskl(spi, 0, LTQ_SPI_RXFCON_RXFLU, LTQ_SPI_RXFCON);
248}
249
250static void tx_fifo_flush(const struct lantiq_ssc_spi *spi)
251{
252 lantiq_ssc_maskl(spi, 0, LTQ_SPI_TXFCON_TXFLU, LTQ_SPI_TXFCON);
253}
254
255static void hw_enter_config_mode(const struct lantiq_ssc_spi *spi)
256{
257 lantiq_ssc_writel(spi, LTQ_SPI_WHBSTATE_CLREN, LTQ_SPI_WHBSTATE);
258}
259
260static void hw_enter_active_mode(const struct lantiq_ssc_spi *spi)
261{
262 lantiq_ssc_writel(spi, LTQ_SPI_WHBSTATE_SETEN, LTQ_SPI_WHBSTATE);
263}
264
265static void hw_setup_speed_hz(const struct lantiq_ssc_spi *spi,
266 unsigned int max_speed_hz)
267{
268 u32 spi_clk, brt;
269
270 /*
271 * SPI module clock is derived from FPI bus clock dependent on
272 * divider value in CLC.RMS which is always set to 1.
273 *
274 * f_SPI
275 * baudrate = --------------
276 * 2 * (BR + 1)
277 */
278 spi_clk = clk_get_rate(spi->fpi_clk) / 2;
279
280 if (max_speed_hz > spi_clk)
281 brt = 0;
282 else
283 brt = spi_clk / max_speed_hz - 1;
284
285 if (brt > 0xFFFF)
286 brt = 0xFFFF;
287
288 dev_dbg(spi->dev, "spi_clk %u, max_speed_hz %u, brt %u\n",
289 spi_clk, max_speed_hz, brt);
290
291 lantiq_ssc_writel(spi, brt, LTQ_SPI_BRT);
292}
293
294static void hw_setup_bits_per_word(const struct lantiq_ssc_spi *spi,
295 unsigned int bits_per_word)
296{
297 u32 bm;
298
299 /* CON.BM value = bits_per_word - 1 */
300 bm = (bits_per_word - 1) << LTQ_SPI_CON_BM_S;
301
302 lantiq_ssc_maskl(spi, LTQ_SPI_CON_BM_M, bm, LTQ_SPI_CON);
303}
304
305static void hw_setup_clock_mode(const struct lantiq_ssc_spi *spi,
306 unsigned int mode)
307{
308 u32 con_set = 0, con_clr = 0;
309
310 /*
311 * SPI mode mapping in CON register:
312 * Mode CPOL CPHA CON.PO CON.PH
313 * 0 0 0 0 1
314 * 1 0 1 0 0
315 * 2 1 0 1 1
316 * 3 1 1 1 0
317 */
318 if (mode & SPI_CPHA)
319 con_clr |= LTQ_SPI_CON_PH;
320 else
321 con_set |= LTQ_SPI_CON_PH;
322
323 if (mode & SPI_CPOL)
324 con_set |= LTQ_SPI_CON_PO | LTQ_SPI_CON_IDLE;
325 else
326 con_clr |= LTQ_SPI_CON_PO | LTQ_SPI_CON_IDLE;
327
328 /* Set heading control */
329 if (mode & SPI_LSB_FIRST)
330 con_clr |= LTQ_SPI_CON_HB;
331 else
332 con_set |= LTQ_SPI_CON_HB;
333
334 /* Set loopback mode */
335 if (mode & SPI_LOOP)
336 con_set |= LTQ_SPI_CON_LB;
337 else
338 con_clr |= LTQ_SPI_CON_LB;
339
340 lantiq_ssc_maskl(spi, con_clr, con_set, LTQ_SPI_CON);
341}
342
343static void lantiq_ssc_hw_init(const struct lantiq_ssc_spi *spi)
344{
345 const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg;
346
347 /*
348 * Set clock divider for run mode to 1 to
349 * run at same frequency as FPI bus
350 */
351 lantiq_ssc_writel(spi, 1 << LTQ_SPI_CLC_RMC_S, LTQ_SPI_CLC);
352
353 /* Put controller into config mode */
354 hw_enter_config_mode(spi);
355
356 /* Clear error flags */
357 lantiq_ssc_maskl(spi, 0, LTQ_SPI_WHBSTATE_CLR_ERRORS, LTQ_SPI_WHBSTATE);
358
359 /* Enable error checking, disable TX/RX */
360 lantiq_ssc_writel(spi, LTQ_SPI_CON_RUEN | LTQ_SPI_CON_AEN |
361 LTQ_SPI_CON_TEN | LTQ_SPI_CON_REN | LTQ_SPI_CON_TXOFF |
362 LTQ_SPI_CON_RXOFF, LTQ_SPI_CON);
363
364 /* Setup default SPI mode */
365 hw_setup_bits_per_word(spi, spi->bits_per_word);
366 hw_setup_clock_mode(spi, SPI_MODE_0);
367
368 /* Enable master mode and clear error flags */
369 lantiq_ssc_writel(spi, LTQ_SPI_WHBSTATE_SETMS |
370 LTQ_SPI_WHBSTATE_CLR_ERRORS,
371 LTQ_SPI_WHBSTATE);
372
373 /* Reset GPIO/CS registers */
374 lantiq_ssc_writel(spi, 0, LTQ_SPI_GPOCON);
375 lantiq_ssc_writel(spi, 0xFF00, LTQ_SPI_FPGO);
376
377 /* Enable and flush FIFOs */
378 rx_fifo_reset(spi);
379 tx_fifo_reset(spi);
380
381 /* Enable interrupts */
382 lantiq_ssc_writel(spi, hwcfg->irnen_t | hwcfg->irnen_r |
383 LTQ_SPI_IRNEN_E, LTQ_SPI_IRNEN);
384}
385
386static int lantiq_ssc_setup(struct spi_device *spidev)
387{
388 struct spi_master *master = spidev->master;
389 struct lantiq_ssc_spi *spi = spi_master_get_devdata(master);
390 unsigned int cs = spidev->chip_select;
391 u32 gpocon;
392
393 /* GPIOs are used for CS */
394 if (gpio_is_valid(spidev->cs_gpio))
395 return 0;
396
397 dev_dbg(spi->dev, "using internal chipselect %u\n", cs);
398
399 if (cs < spi->base_cs) {
400 dev_err(spi->dev,
401 "chipselect %i too small (min %i)\n", cs, spi->base_cs);
402 return -EINVAL;
403 }
404
405 /* set GPO pin to CS mode */
406 gpocon = 1 << ((cs - spi->base_cs) + LTQ_SPI_GPOCON_ISCSBN_S);
407
408 /* invert GPO pin */
409 if (spidev->mode & SPI_CS_HIGH)
410 gpocon |= 1 << (cs - spi->base_cs);
411
412 lantiq_ssc_maskl(spi, 0, gpocon, LTQ_SPI_GPOCON);
413
414 return 0;
415}
416
417static int lantiq_ssc_prepare_message(struct spi_master *master,
418 struct spi_message *message)
419{
420 struct lantiq_ssc_spi *spi = spi_master_get_devdata(master);
421
422 hw_enter_config_mode(spi);
423 hw_setup_clock_mode(spi, message->spi->mode);
424 hw_enter_active_mode(spi);
425
426 return 0;
427}
428
429static void hw_setup_transfer(struct lantiq_ssc_spi *spi,
430 struct spi_device *spidev, struct spi_transfer *t)
431{
432 unsigned int speed_hz = t->speed_hz;
433 unsigned int bits_per_word = t->bits_per_word;
434 u32 con;
435
436 if (bits_per_word != spi->bits_per_word ||
437 speed_hz != spi->speed_hz) {
438 hw_enter_config_mode(spi);
439 hw_setup_speed_hz(spi, speed_hz);
440 hw_setup_bits_per_word(spi, bits_per_word);
441 hw_enter_active_mode(spi);
442
443 spi->speed_hz = speed_hz;
444 spi->bits_per_word = bits_per_word;
445 }
446
447 /* Configure transmitter and receiver */
448 con = lantiq_ssc_readl(spi, LTQ_SPI_CON);
449 if (t->tx_buf)
450 con &= ~LTQ_SPI_CON_TXOFF;
451 else
452 con |= LTQ_SPI_CON_TXOFF;
453
454 if (t->rx_buf)
455 con &= ~LTQ_SPI_CON_RXOFF;
456 else
457 con |= LTQ_SPI_CON_RXOFF;
458
459 lantiq_ssc_writel(spi, con, LTQ_SPI_CON);
460}
461
462static int lantiq_ssc_unprepare_message(struct spi_master *master,
463 struct spi_message *message)
464{
465 struct lantiq_ssc_spi *spi = spi_master_get_devdata(master);
466
467 flush_workqueue(spi->wq);
468
469 /* Disable transmitter and receiver while idle */
470 lantiq_ssc_maskl(spi, 0, LTQ_SPI_CON_TXOFF | LTQ_SPI_CON_RXOFF,
471 LTQ_SPI_CON);
472
473 return 0;
474}
475
476static void tx_fifo_write(struct lantiq_ssc_spi *spi)
477{
478 const u8 *tx8;
479 const u16 *tx16;
480 const u32 *tx32;
481 u32 data;
482 unsigned int tx_free = tx_fifo_free(spi);
483
484 while (spi->tx_todo && tx_free) {
485 switch (spi->bits_per_word) {
486 case 2 ... 8:
487 tx8 = spi->tx;
488 data = *tx8;
489 spi->tx_todo--;
490 spi->tx++;
491 break;
492 case 16:
493 tx16 = (u16 *) spi->tx;
494 data = *tx16;
495 spi->tx_todo -= 2;
496 spi->tx += 2;
497 break;
498 case 32:
499 tx32 = (u32 *) spi->tx;
500 data = *tx32;
501 spi->tx_todo -= 4;
502 spi->tx += 4;
503 break;
504 default:
505 WARN_ON(1);
506 data = 0;
507 break;
508 }
509
510 lantiq_ssc_writel(spi, data, LTQ_SPI_TB);
511 tx_free--;
512 }
513}
514
515static void rx_fifo_read_full_duplex(struct lantiq_ssc_spi *spi)
516{
517 u8 *rx8;
518 u16 *rx16;
519 u32 *rx32;
520 u32 data;
521 unsigned int rx_fill = rx_fifo_level(spi);
522
523 while (rx_fill) {
524 data = lantiq_ssc_readl(spi, LTQ_SPI_RB);
525
526 switch (spi->bits_per_word) {
527 case 2 ... 8:
528 rx8 = spi->rx;
529 *rx8 = data;
530 spi->rx_todo--;
531 spi->rx++;
532 break;
533 case 16:
534 rx16 = (u16 *) spi->rx;
535 *rx16 = data;
536 spi->rx_todo -= 2;
537 spi->rx += 2;
538 break;
539 case 32:
540 rx32 = (u32 *) spi->rx;
541 *rx32 = data;
542 spi->rx_todo -= 4;
543 spi->rx += 4;
544 break;
545 default:
546 WARN_ON(1);
547 break;
548 }
549
550 rx_fill--;
551 }
552}
553
554static void rx_fifo_read_half_duplex(struct lantiq_ssc_spi *spi)
555{
556 u32 data, *rx32;
557 u8 *rx8;
558 unsigned int rxbv, shift;
559 unsigned int rx_fill = rx_fifo_level(spi);
560
561 /*
562 * In RX-only mode the bits per word value is ignored by HW. A value
563 * of 32 is used instead. Thus all 4 bytes per FIFO must be read.
564 * If remaining RX bytes are less than 4, the FIFO must be read
565 * differently. The amount of received and valid bytes is indicated
566 * by STAT.RXBV register value.
567 */
568 while (rx_fill) {
569 if (spi->rx_todo < 4) {
570 rxbv = (lantiq_ssc_readl(spi, LTQ_SPI_STAT) &
571 LTQ_SPI_STAT_RXBV_M) >> LTQ_SPI_STAT_RXBV_S;
572 data = lantiq_ssc_readl(spi, LTQ_SPI_RB);
573
574 shift = (rxbv - 1) * 8;
575 rx8 = spi->rx;
576
577 while (rxbv) {
578 *rx8++ = (data >> shift) & 0xFF;
579 rxbv--;
580 shift -= 8;
581 spi->rx_todo--;
582 spi->rx++;
583 }
584 } else {
585 data = lantiq_ssc_readl(spi, LTQ_SPI_RB);
586 rx32 = (u32 *) spi->rx;
587
588 *rx32++ = data;
589 spi->rx_todo -= 4;
590 spi->rx += 4;
591 }
592 rx_fill--;
593 }
594}
595
596static void rx_request(struct lantiq_ssc_spi *spi)
597{
598 unsigned int rxreq, rxreq_max;
599
600 /*
601 * To avoid receive overflows at high clocks it is better to request
602 * only the amount of bytes that fits into all FIFOs. This value
603 * depends on the FIFO size implemented in hardware.
604 */
605 rxreq = spi->rx_todo;
606 rxreq_max = spi->rx_fifo_size * 4;
607 if (rxreq > rxreq_max)
608 rxreq = rxreq_max;
609
610 lantiq_ssc_writel(spi, rxreq, LTQ_SPI_RXREQ);
611}
612
613static irqreturn_t lantiq_ssc_xmit_interrupt(int irq, void *data)
614{
615 struct lantiq_ssc_spi *spi = data;
616
617 if (spi->tx) {
618 if (spi->rx && spi->rx_todo)
619 rx_fifo_read_full_duplex(spi);
620
621 if (spi->tx_todo)
622 tx_fifo_write(spi);
623 else if (!tx_fifo_level(spi))
624 goto completed;
625 } else if (spi->rx) {
626 if (spi->rx_todo) {
627 rx_fifo_read_half_duplex(spi);
628
629 if (spi->rx_todo)
630 rx_request(spi);
631 else
632 goto completed;
633 } else {
634 goto completed;
635 }
636 }
637
638 return IRQ_HANDLED;
639
640completed:
641 queue_work(spi->wq, &spi->work);
642
643 return IRQ_HANDLED;
644}
645
646static irqreturn_t lantiq_ssc_err_interrupt(int irq, void *data)
647{
648 struct lantiq_ssc_spi *spi = data;
649 u32 stat = lantiq_ssc_readl(spi, LTQ_SPI_STAT);
650
651 if (!(stat & LTQ_SPI_STAT_ERRORS))
652 return IRQ_NONE;
653
654 if (stat & LTQ_SPI_STAT_RUE)
655 dev_err(spi->dev, "receive underflow error\n");
656 if (stat & LTQ_SPI_STAT_TUE)
657 dev_err(spi->dev, "transmit underflow error\n");
658 if (stat & LTQ_SPI_STAT_AE)
659 dev_err(spi->dev, "abort error\n");
660 if (stat & LTQ_SPI_STAT_RE)
661 dev_err(spi->dev, "receive overflow error\n");
662 if (stat & LTQ_SPI_STAT_TE)
663 dev_err(spi->dev, "transmit overflow error\n");
664 if (stat & LTQ_SPI_STAT_ME)
665 dev_err(spi->dev, "mode error\n");
666
667 /* Clear error flags */
668 lantiq_ssc_maskl(spi, 0, LTQ_SPI_WHBSTATE_CLR_ERRORS, LTQ_SPI_WHBSTATE);
669
670 /* set bad status so it can be retried */
671 if (spi->master->cur_msg)
672 spi->master->cur_msg->status = -EIO;
673 queue_work(spi->wq, &spi->work);
674
675 return IRQ_HANDLED;
676}
677
678static int transfer_start(struct lantiq_ssc_spi *spi, struct spi_device *spidev,
679 struct spi_transfer *t)
680{
681 unsigned long flags;
682
683 spin_lock_irqsave(&spi->lock, flags);
684
685 spi->tx = t->tx_buf;
686 spi->rx = t->rx_buf;
687
688 if (t->tx_buf) {
689 spi->tx_todo = t->len;
690
691 /* initially fill TX FIFO */
692 tx_fifo_write(spi);
693 }
694
695 if (spi->rx) {
696 spi->rx_todo = t->len;
697
698 /* start shift clock in RX-only mode */
699 if (!spi->tx)
700 rx_request(spi);
701 }
702
703 spin_unlock_irqrestore(&spi->lock, flags);
704
705 return t->len;
706}
707
708/*
709 * The driver only gets an interrupt when the FIFO is empty, but there
710 * is an additional shift register from which the data is written to
711 * the wire. We get the last interrupt when the controller starts to
712 * write the last word to the wire, not when it is finished. Do busy
713 * waiting till it finishes.
714 */
715static void lantiq_ssc_bussy_work(struct work_struct *work)
716{
717 struct lantiq_ssc_spi *spi;
718 unsigned long long timeout = 8LL * 1000LL;
719 unsigned long end;
720
721 spi = container_of(work, typeof(*spi), work);
722
723 do_div(timeout, spi->speed_hz);
724 timeout += timeout + 100; /* some tolerance */
725
726 end = jiffies + msecs_to_jiffies(timeout);
727 do {
728 u32 stat = lantiq_ssc_readl(spi, LTQ_SPI_STAT);
729
730 if (!(stat & LTQ_SPI_STAT_BSY)) {
731 spi_finalize_current_transfer(spi->master);
732 return;
733 }
734
735 cond_resched();
736 } while (!time_after_eq(jiffies, end));
737
738 if (spi->master->cur_msg)
739 spi->master->cur_msg->status = -EIO;
740 spi_finalize_current_transfer(spi->master);
741}
742
743static void lantiq_ssc_handle_err(struct spi_master *master,
744 struct spi_message *message)
745{
746 struct lantiq_ssc_spi *spi = spi_master_get_devdata(master);
747
748 /* flush FIFOs on timeout */
749 rx_fifo_flush(spi);
750 tx_fifo_flush(spi);
751}
752
753static void lantiq_ssc_set_cs(struct spi_device *spidev, bool enable)
754{
755 struct lantiq_ssc_spi *spi = spi_master_get_devdata(spidev->master);
756 unsigned int cs = spidev->chip_select;
757 u32 fgpo;
758
759 if (!!(spidev->mode & SPI_CS_HIGH) == enable)
760 fgpo = (1 << (cs - spi->base_cs));
761 else
762 fgpo = (1 << (cs - spi->base_cs + LTQ_SPI_FGPO_SETOUTN_S));
763
764 lantiq_ssc_writel(spi, fgpo, LTQ_SPI_FPGO);
765}
766
767static int lantiq_ssc_transfer_one(struct spi_master *master,
768 struct spi_device *spidev,
769 struct spi_transfer *t)
770{
771 struct lantiq_ssc_spi *spi = spi_master_get_devdata(master);
772
773 hw_setup_transfer(spi, spidev, t);
774
775 return transfer_start(spi, spidev, t);
776}
777
778static const struct lantiq_ssc_hwcfg lantiq_ssc_xway = {
779 .irnen_r = LTQ_SPI_IRNEN_R_XWAY,
780 .irnen_t = LTQ_SPI_IRNEN_T_XWAY,
781};
782
783static const struct lantiq_ssc_hwcfg lantiq_ssc_xrx = {
784 .irnen_r = LTQ_SPI_IRNEN_R_XRX,
785 .irnen_t = LTQ_SPI_IRNEN_T_XRX,
786};
787
788static const struct of_device_id lantiq_ssc_match[] = {
789 { .compatible = "lantiq,ase-spi", .data = &lantiq_ssc_xway, },
790 { .compatible = "lantiq,falcon-spi", .data = &lantiq_ssc_xrx, },
791 { .compatible = "lantiq,xrx100-spi", .data = &lantiq_ssc_xrx, },
792 {},
793};
794MODULE_DEVICE_TABLE(of, lantiq_ssc_match);
795
796static int lantiq_ssc_probe(struct platform_device *pdev)
797{
798 struct device *dev = &pdev->dev;
799 struct spi_master *master;
800 struct resource *res;
801 struct lantiq_ssc_spi *spi;
802 const struct lantiq_ssc_hwcfg *hwcfg;
803 const struct of_device_id *match;
804 int err, rx_irq, tx_irq, err_irq;
805 u32 id, supports_dma, revision;
806 unsigned int num_cs;
807
808 match = of_match_device(lantiq_ssc_match, dev);
809 if (!match) {
810 dev_err(dev, "no device match\n");
811 return -EINVAL;
812 }
813 hwcfg = match->data;
814
815 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
816 if (!res) {
817 dev_err(dev, "failed to get resources\n");
818 return -ENXIO;
819 }
820
821 rx_irq = platform_get_irq_byname(pdev, LTQ_SPI_RX_IRQ_NAME);
822 if (rx_irq < 0)
823 return -ENXIO;
824
825 tx_irq = platform_get_irq_byname(pdev, LTQ_SPI_TX_IRQ_NAME);
826 if (tx_irq < 0)
827 return -ENXIO;
828
829 err_irq = platform_get_irq_byname(pdev, LTQ_SPI_ERR_IRQ_NAME);
830 if (err_irq < 0)
831 return -ENXIO;
832
833 master = spi_alloc_master(dev, sizeof(struct lantiq_ssc_spi));
834 if (!master)
835 return -ENOMEM;
836
837 spi = spi_master_get_devdata(master);
838 spi->master = master;
839 spi->dev = dev;
840 spi->hwcfg = hwcfg;
841 platform_set_drvdata(pdev, spi);
842
843 spi->regbase = devm_ioremap_resource(dev, res);
844 if (IS_ERR(spi->regbase)) {
845 err = PTR_ERR(spi->regbase);
846 goto err_master_put;
847 }
848
849 err = devm_request_irq(dev, rx_irq, lantiq_ssc_xmit_interrupt,
850 0, LTQ_SPI_RX_IRQ_NAME, spi);
851 if (err)
852 goto err_master_put;
853
854 err = devm_request_irq(dev, tx_irq, lantiq_ssc_xmit_interrupt,
855 0, LTQ_SPI_TX_IRQ_NAME, spi);
856 if (err)
857 goto err_master_put;
858
859 err = devm_request_irq(dev, err_irq, lantiq_ssc_err_interrupt,
860 0, LTQ_SPI_ERR_IRQ_NAME, spi);
861 if (err)
862 goto err_master_put;
863
864 spi->spi_clk = devm_clk_get(dev, "gate");
865 if (IS_ERR(spi->spi_clk)) {
866 err = PTR_ERR(spi->spi_clk);
867 goto err_master_put;
868 }
869 err = clk_prepare_enable(spi->spi_clk);
870 if (err)
871 goto err_master_put;
872
873 /*
874 * Use the old clk_get_fpi() function on Lantiq platform, till it
875 * supports common clk.
876 */
877#if defined(CONFIG_LANTIQ) && !defined(CONFIG_COMMON_CLK)
878 spi->fpi_clk = clk_get_fpi();
879#else
880 spi->fpi_clk = clk_get(dev, "freq");
881#endif
882 if (IS_ERR(spi->fpi_clk)) {
883 err = PTR_ERR(spi->fpi_clk);
884 goto err_clk_disable;
885 }
886
887 num_cs = 8;
888 of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs);
889
890 spi->base_cs = 1;
891 of_property_read_u32(pdev->dev.of_node, "base-cs", &spi->base_cs);
892
893 spin_lock_init(&spi->lock);
894 spi->bits_per_word = 8;
895 spi->speed_hz = 0;
896
897 master->dev.of_node = pdev->dev.of_node;
898 master->num_chipselect = num_cs;
899 master->setup = lantiq_ssc_setup;
900 master->set_cs = lantiq_ssc_set_cs;
901 master->handle_err = lantiq_ssc_handle_err;
902 master->prepare_message = lantiq_ssc_prepare_message;
903 master->unprepare_message = lantiq_ssc_unprepare_message;
904 master->transfer_one = lantiq_ssc_transfer_one;
905 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_CS_HIGH |
906 SPI_LOOP;
907 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 8) |
908 SPI_BPW_MASK(16) | SPI_BPW_MASK(32);
909
910 spi->wq = alloc_ordered_workqueue(dev_name(dev), 0);
911 if (!spi->wq) {
912 err = -ENOMEM;
913 goto err_clk_put;
914 }
915 INIT_WORK(&spi->work, lantiq_ssc_bussy_work);
916
917 id = lantiq_ssc_readl(spi, LTQ_SPI_ID);
918 spi->tx_fifo_size = (id & LTQ_SPI_ID_TXFS_M) >> LTQ_SPI_ID_TXFS_S;
919 spi->rx_fifo_size = (id & LTQ_SPI_ID_RXFS_M) >> LTQ_SPI_ID_RXFS_S;
920 supports_dma = (id & LTQ_SPI_ID_CFG_M) >> LTQ_SPI_ID_CFG_S;
921 revision = id & LTQ_SPI_ID_REV_M;
922
923 lantiq_ssc_hw_init(spi);
924
925 dev_info(dev,
926 "Lantiq SSC SPI controller (Rev %i, TXFS %u, RXFS %u, DMA %u)\n",
927 revision, spi->tx_fifo_size, spi->rx_fifo_size, supports_dma);
928
929 err = devm_spi_register_master(dev, master);
930 if (err) {
931 dev_err(dev, "failed to register spi_master\n");
932 goto err_wq_destroy;
933 }
934
935 return 0;
936
937err_wq_destroy:
938 destroy_workqueue(spi->wq);
939err_clk_put:
940 clk_put(spi->fpi_clk);
941err_clk_disable:
942 clk_disable_unprepare(spi->spi_clk);
943err_master_put:
944 spi_master_put(master);
945
946 return err;
947}
948
949static int lantiq_ssc_remove(struct platform_device *pdev)
950{
951 struct lantiq_ssc_spi *spi = platform_get_drvdata(pdev);
952
953 lantiq_ssc_writel(spi, 0, LTQ_SPI_IRNEN);
954 lantiq_ssc_writel(spi, 0, LTQ_SPI_CLC);
955 rx_fifo_flush(spi);
956 tx_fifo_flush(spi);
957 hw_enter_config_mode(spi);
958
959 destroy_workqueue(spi->wq);
960 clk_disable_unprepare(spi->spi_clk);
961 clk_put(spi->fpi_clk);
962
963 return 0;
964}
965
966static struct platform_driver lantiq_ssc_driver = {
967 .probe = lantiq_ssc_probe,
968 .remove = lantiq_ssc_remove,
969 .driver = {
970 .name = "spi-lantiq-ssc",
971 .of_match_table = lantiq_ssc_match,
972 },
973};
974module_platform_driver(lantiq_ssc_driver);
975
976MODULE_DESCRIPTION("Lantiq SSC SPI controller driver");
977MODULE_AUTHOR("Daniel Schwierzeck <daniel.schwierzeck@gmail.com>");
978MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
979MODULE_LICENSE("GPL");
980MODULE_ALIAS("platform:spi-lantiq-ssc");