Version:  2.0.40 2.2.26 2.4.37 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

Linux/drivers/spi/spi-sh-msiof.c

  1 /*
  2  * SuperH MSIOF SPI Master Interface
  3  *
  4  * Copyright (c) 2009 Magnus Damm
  5  * Copyright (C) 2014 Glider bvba
  6  *
  7  * This program is free software; you can redistribute it and/or modify
  8  * it under the terms of the GNU General Public License version 2 as
  9  * published by the Free Software Foundation.
 10  *
 11  */
 12 
 13 #include <linux/bitmap.h>
 14 #include <linux/clk.h>
 15 #include <linux/completion.h>
 16 #include <linux/delay.h>
 17 #include <linux/dma-mapping.h>
 18 #include <linux/dmaengine.h>
 19 #include <linux/err.h>
 20 #include <linux/gpio.h>
 21 #include <linux/interrupt.h>
 22 #include <linux/io.h>
 23 #include <linux/kernel.h>
 24 #include <linux/module.h>
 25 #include <linux/of.h>
 26 #include <linux/of_device.h>
 27 #include <linux/platform_device.h>
 28 #include <linux/pm_runtime.h>
 29 #include <linux/sh_dma.h>
 30 
 31 #include <linux/spi/sh_msiof.h>
 32 #include <linux/spi/spi.h>
 33 
 34 #include <asm/unaligned.h>
 35 
 36 
 37 struct sh_msiof_chipdata {
 38         u16 tx_fifo_size;
 39         u16 rx_fifo_size;
 40         u16 master_flags;
 41 };
 42 
 43 struct sh_msiof_spi_priv {
 44         struct spi_master *master;
 45         void __iomem *mapbase;
 46         struct clk *clk;
 47         struct platform_device *pdev;
 48         struct sh_msiof_spi_info *info;
 49         struct completion done;
 50         unsigned int tx_fifo_size;
 51         unsigned int rx_fifo_size;
 52         void *tx_dma_page;
 53         void *rx_dma_page;
 54         dma_addr_t tx_dma_addr;
 55         dma_addr_t rx_dma_addr;
 56 };
 57 
 58 #define TMDR1   0x00    /* Transmit Mode Register 1 */
 59 #define TMDR2   0x04    /* Transmit Mode Register 2 */
 60 #define TMDR3   0x08    /* Transmit Mode Register 3 */
 61 #define RMDR1   0x10    /* Receive Mode Register 1 */
 62 #define RMDR2   0x14    /* Receive Mode Register 2 */
 63 #define RMDR3   0x18    /* Receive Mode Register 3 */
 64 #define TSCR    0x20    /* Transmit Clock Select Register */
 65 #define RSCR    0x22    /* Receive Clock Select Register (SH, A1, APE6) */
 66 #define CTR     0x28    /* Control Register */
 67 #define FCTR    0x30    /* FIFO Control Register */
 68 #define STR     0x40    /* Status Register */
 69 #define IER     0x44    /* Interrupt Enable Register */
 70 #define TDR1    0x48    /* Transmit Control Data Register 1 (SH, A1) */
 71 #define TDR2    0x4c    /* Transmit Control Data Register 2 (SH, A1) */
 72 #define TFDR    0x50    /* Transmit FIFO Data Register */
 73 #define RDR1    0x58    /* Receive Control Data Register 1 (SH, A1) */
 74 #define RDR2    0x5c    /* Receive Control Data Register 2 (SH, A1) */
 75 #define RFDR    0x60    /* Receive FIFO Data Register */
 76 
 77 /* TMDR1 and RMDR1 */
 78 #define MDR1_TRMD        0x80000000 /* Transfer Mode (1 = Master mode) */
 79 #define MDR1_SYNCMD_MASK 0x30000000 /* SYNC Mode */
 80 #define MDR1_SYNCMD_SPI  0x20000000 /*   Level mode/SPI */
 81 #define MDR1_SYNCMD_LR   0x30000000 /*   L/R mode */
 82 #define MDR1_SYNCAC_SHIFT        25 /* Sync Polarity (1 = Active-low) */
 83 #define MDR1_BITLSB_SHIFT        24 /* MSB/LSB First (1 = LSB first) */
 84 #define MDR1_DTDL_SHIFT          20 /* Data Pin Bit Delay for MSIOF_SYNC */
 85 #define MDR1_SYNCDL_SHIFT        16 /* Frame Sync Signal Timing Delay */
 86 #define MDR1_FLD_MASK    0x0000000c /* Frame Sync Signal Interval (0-3) */
 87 #define MDR1_FLD_SHIFT            2
 88 #define MDR1_XXSTP       0x00000001 /* Transmission/Reception Stop on FIFO */
 89 /* TMDR1 */
 90 #define TMDR1_PCON       0x40000000 /* Transfer Signal Connection */
 91 
 92 /* TMDR2 and RMDR2 */
 93 #define MDR2_BITLEN1(i) (((i) - 1) << 24) /* Data Size (8-32 bits) */
 94 #define MDR2_WDLEN1(i)  (((i) - 1) << 16) /* Word Count (1-64/256 (SH, A1))) */
 95 #define MDR2_GRPMASK1   0x00000001 /* Group Output Mask 1 (SH, A1) */
 96 
 97 /* TSCR and RSCR */
 98 #define SCR_BRPS_MASK       0x1f00 /* Prescaler Setting (1-32) */
 99 #define SCR_BRPS(i)     (((i) - 1) << 8)
100 #define SCR_BRDV_MASK       0x0007 /* Baud Rate Generator's Division Ratio */
101 #define SCR_BRDV_DIV_2      0x0000
102 #define SCR_BRDV_DIV_4      0x0001
103 #define SCR_BRDV_DIV_8      0x0002
104 #define SCR_BRDV_DIV_16     0x0003
105 #define SCR_BRDV_DIV_32     0x0004
106 #define SCR_BRDV_DIV_1      0x0007
107 
108 /* CTR */
109 #define CTR_TSCKIZ_MASK 0xc0000000 /* Transmit Clock I/O Polarity Select */
110 #define CTR_TSCKIZ_SCK  0x80000000 /*   Disable SCK when TX disabled */
111 #define CTR_TSCKIZ_POL_SHIFT    30 /*   Transmit Clock Polarity */
112 #define CTR_RSCKIZ_MASK 0x30000000 /* Receive Clock Polarity Select */
113 #define CTR_RSCKIZ_SCK  0x20000000 /*   Must match CTR_TSCKIZ_SCK */
114 #define CTR_RSCKIZ_POL_SHIFT    28 /*   Receive Clock Polarity */
115 #define CTR_TEDG_SHIFT          27 /* Transmit Timing (1 = falling edge) */
116 #define CTR_REDG_SHIFT          26 /* Receive Timing (1 = falling edge) */
117 #define CTR_TXDIZ_MASK  0x00c00000 /* Pin Output When TX is Disabled */
118 #define CTR_TXDIZ_LOW   0x00000000 /*   0 */
119 #define CTR_TXDIZ_HIGH  0x00400000 /*   1 */
120 #define CTR_TXDIZ_HIZ   0x00800000 /*   High-impedance */
121 #define CTR_TSCKE       0x00008000 /* Transmit Serial Clock Output Enable */
122 #define CTR_TFSE        0x00004000 /* Transmit Frame Sync Signal Output Enable */
123 #define CTR_TXE         0x00000200 /* Transmit Enable */
124 #define CTR_RXE         0x00000100 /* Receive Enable */
125 
126 /* FCTR */
127 #define FCTR_TFWM_MASK  0xe0000000 /* Transmit FIFO Watermark */
128 #define FCTR_TFWM_64    0x00000000 /*  Transfer Request when 64 empty stages */
129 #define FCTR_TFWM_32    0x20000000 /*  Transfer Request when 32 empty stages */
130 #define FCTR_TFWM_24    0x40000000 /*  Transfer Request when 24 empty stages */
131 #define FCTR_TFWM_16    0x60000000 /*  Transfer Request when 16 empty stages */
132 #define FCTR_TFWM_12    0x80000000 /*  Transfer Request when 12 empty stages */
133 #define FCTR_TFWM_8     0xa0000000 /*  Transfer Request when 8 empty stages */
134 #define FCTR_TFWM_4     0xc0000000 /*  Transfer Request when 4 empty stages */
135 #define FCTR_TFWM_1     0xe0000000 /*  Transfer Request when 1 empty stage */
136 #define FCTR_TFUA_MASK  0x07f00000 /* Transmit FIFO Usable Area */
137 #define FCTR_TFUA_SHIFT         20
138 #define FCTR_TFUA(i)    ((i) << FCTR_TFUA_SHIFT)
139 #define FCTR_RFWM_MASK  0x0000e000 /* Receive FIFO Watermark */
140 #define FCTR_RFWM_1     0x00000000 /*  Transfer Request when 1 valid stages */
141 #define FCTR_RFWM_4     0x00002000 /*  Transfer Request when 4 valid stages */
142 #define FCTR_RFWM_8     0x00004000 /*  Transfer Request when 8 valid stages */
143 #define FCTR_RFWM_16    0x00006000 /*  Transfer Request when 16 valid stages */
144 #define FCTR_RFWM_32    0x00008000 /*  Transfer Request when 32 valid stages */
145 #define FCTR_RFWM_64    0x0000a000 /*  Transfer Request when 64 valid stages */
146 #define FCTR_RFWM_128   0x0000c000 /*  Transfer Request when 128 valid stages */
147 #define FCTR_RFWM_256   0x0000e000 /*  Transfer Request when 256 valid stages */
148 #define FCTR_RFUA_MASK  0x00001ff0 /* Receive FIFO Usable Area (0x40 = full) */
149 #define FCTR_RFUA_SHIFT          4
150 #define FCTR_RFUA(i)    ((i) << FCTR_RFUA_SHIFT)
151 
152 /* STR */
153 #define STR_TFEMP       0x20000000 /* Transmit FIFO Empty */
154 #define STR_TDREQ       0x10000000 /* Transmit Data Transfer Request */
155 #define STR_TEOF        0x00800000 /* Frame Transmission End */
156 #define STR_TFSERR      0x00200000 /* Transmit Frame Synchronization Error */
157 #define STR_TFOVF       0x00100000 /* Transmit FIFO Overflow */
158 #define STR_TFUDF       0x00080000 /* Transmit FIFO Underflow */
159 #define STR_RFFUL       0x00002000 /* Receive FIFO Full */
160 #define STR_RDREQ       0x00001000 /* Receive Data Transfer Request */
161 #define STR_REOF        0x00000080 /* Frame Reception End */
162 #define STR_RFSERR      0x00000020 /* Receive Frame Synchronization Error */
163 #define STR_RFUDF       0x00000010 /* Receive FIFO Underflow */
164 #define STR_RFOVF       0x00000008 /* Receive FIFO Overflow */
165 
166 /* IER */
167 #define IER_TDMAE       0x80000000 /* Transmit Data DMA Transfer Req. Enable */
168 #define IER_TFEMPE      0x20000000 /* Transmit FIFO Empty Enable */
169 #define IER_TDREQE      0x10000000 /* Transmit Data Transfer Request Enable */
170 #define IER_TEOFE       0x00800000 /* Frame Transmission End Enable */
171 #define IER_TFSERRE     0x00200000 /* Transmit Frame Sync Error Enable */
172 #define IER_TFOVFE      0x00100000 /* Transmit FIFO Overflow Enable */
173 #define IER_TFUDFE      0x00080000 /* Transmit FIFO Underflow Enable */
174 #define IER_RDMAE       0x00008000 /* Receive Data DMA Transfer Req. Enable */
175 #define IER_RFFULE      0x00002000 /* Receive FIFO Full Enable */
176 #define IER_RDREQE      0x00001000 /* Receive Data Transfer Request Enable */
177 #define IER_REOFE       0x00000080 /* Frame Reception End Enable */
178 #define IER_RFSERRE     0x00000020 /* Receive Frame Sync Error Enable */
179 #define IER_RFUDFE      0x00000010 /* Receive FIFO Underflow Enable */
180 #define IER_RFOVFE      0x00000008 /* Receive FIFO Overflow Enable */
181 
182 
183 static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
184 {
185         switch (reg_offs) {
186         case TSCR:
187         case RSCR:
188                 return ioread16(p->mapbase + reg_offs);
189         default:
190                 return ioread32(p->mapbase + reg_offs);
191         }
192 }
193 
194 static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
195                            u32 value)
196 {
197         switch (reg_offs) {
198         case TSCR:
199         case RSCR:
200                 iowrite16(value, p->mapbase + reg_offs);
201                 break;
202         default:
203                 iowrite32(value, p->mapbase + reg_offs);
204                 break;
205         }
206 }
207 
208 static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
209                                     u32 clr, u32 set)
210 {
211         u32 mask = clr | set;
212         u32 data;
213         int k;
214 
215         data = sh_msiof_read(p, CTR);
216         data &= ~clr;
217         data |= set;
218         sh_msiof_write(p, CTR, data);
219 
220         for (k = 100; k > 0; k--) {
221                 if ((sh_msiof_read(p, CTR) & mask) == set)
222                         break;
223 
224                 udelay(10);
225         }
226 
227         return k > 0 ? 0 : -ETIMEDOUT;
228 }
229 
230 static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
231 {
232         struct sh_msiof_spi_priv *p = data;
233 
234         /* just disable the interrupt and wake up */
235         sh_msiof_write(p, IER, 0);
236         complete(&p->done);
237 
238         return IRQ_HANDLED;
239 }
240 
241 static struct {
242         unsigned short div;
243         unsigned short brdv;
244 } const sh_msiof_spi_div_table[] = {
245         { 1,    SCR_BRDV_DIV_1 },
246         { 2,    SCR_BRDV_DIV_2 },
247         { 4,    SCR_BRDV_DIV_4 },
248         { 8,    SCR_BRDV_DIV_8 },
249         { 16,   SCR_BRDV_DIV_16 },
250         { 32,   SCR_BRDV_DIV_32 },
251 };
252 
253 static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
254                                       unsigned long parent_rate, u32 spi_hz)
255 {
256         unsigned long div = 1024;
257         u32 brps, scr;
258         size_t k;
259 
260         if (!WARN_ON(!spi_hz || !parent_rate))
261                 div = DIV_ROUND_UP(parent_rate, spi_hz);
262 
263         for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_div_table); k++) {
264                 brps = DIV_ROUND_UP(div, sh_msiof_spi_div_table[k].div);
265                 /* SCR_BRDV_DIV_1 is valid only if BRPS is x 1/1 or x 1/2 */
266                 if (sh_msiof_spi_div_table[k].div == 1 && brps > 2)
267                         continue;
268                 if (brps <= 32) /* max of brdv is 32 */
269                         break;
270         }
271 
272         k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_div_table) - 1);
273 
274         scr = sh_msiof_spi_div_table[k].brdv | SCR_BRPS(brps);
275         sh_msiof_write(p, TSCR, scr);
276         if (!(p->master->flags & SPI_MASTER_MUST_TX))
277                 sh_msiof_write(p, RSCR, scr);
278 }
279 
280 static u32 sh_msiof_get_delay_bit(u32 dtdl_or_syncdl)
281 {
282         /*
283          * DTDL/SYNCDL bit      : p->info->dtdl or p->info->syncdl
284          * b'000                : 0
285          * b'001                : 100
286          * b'010                : 200
287          * b'011 (SYNCDL only)  : 300
288          * b'101                : 50
289          * b'110                : 150
290          */
291         if (dtdl_or_syncdl % 100)
292                 return dtdl_or_syncdl / 100 + 5;
293         else
294                 return dtdl_or_syncdl / 100;
295 }
296 
297 static u32 sh_msiof_spi_get_dtdl_and_syncdl(struct sh_msiof_spi_priv *p)
298 {
299         u32 val;
300 
301         if (!p->info)
302                 return 0;
303 
304         /* check if DTDL and SYNCDL is allowed value */
305         if (p->info->dtdl > 200 || p->info->syncdl > 300) {
306                 dev_warn(&p->pdev->dev, "DTDL or SYNCDL is too large\n");
307                 return 0;
308         }
309 
310         /* check if the sum of DTDL and SYNCDL becomes an integer value  */
311         if ((p->info->dtdl + p->info->syncdl) % 100) {
312                 dev_warn(&p->pdev->dev, "the sum of DTDL/SYNCDL is not good\n");
313                 return 0;
314         }
315 
316         val = sh_msiof_get_delay_bit(p->info->dtdl) << MDR1_DTDL_SHIFT;
317         val |= sh_msiof_get_delay_bit(p->info->syncdl) << MDR1_SYNCDL_SHIFT;
318 
319         return val;
320 }
321 
322 static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
323                                       u32 cpol, u32 cpha,
324                                       u32 tx_hi_z, u32 lsb_first, u32 cs_high)
325 {
326         u32 tmp;
327         int edge;
328 
329         /*
330          * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG
331          *    0    0         10     10    1    1
332          *    0    1         10     10    0    0
333          *    1    0         11     11    0    0
334          *    1    1         11     11    1    1
335          */
336         tmp = MDR1_SYNCMD_SPI | 1 << MDR1_FLD_SHIFT | MDR1_XXSTP;
337         tmp |= !cs_high << MDR1_SYNCAC_SHIFT;
338         tmp |= lsb_first << MDR1_BITLSB_SHIFT;
339         tmp |= sh_msiof_spi_get_dtdl_and_syncdl(p);
340         sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON);
341         if (p->master->flags & SPI_MASTER_MUST_TX) {
342                 /* These bits are reserved if RX needs TX */
343                 tmp &= ~0x0000ffff;
344         }
345         sh_msiof_write(p, RMDR1, tmp);
346 
347         tmp = 0;
348         tmp |= CTR_TSCKIZ_SCK | cpol << CTR_TSCKIZ_POL_SHIFT;
349         tmp |= CTR_RSCKIZ_SCK | cpol << CTR_RSCKIZ_POL_SHIFT;
350 
351         edge = cpol ^ !cpha;
352 
353         tmp |= edge << CTR_TEDG_SHIFT;
354         tmp |= edge << CTR_REDG_SHIFT;
355         tmp |= tx_hi_z ? CTR_TXDIZ_HIZ : CTR_TXDIZ_LOW;
356         sh_msiof_write(p, CTR, tmp);
357 }
358 
359 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
360                                        const void *tx_buf, void *rx_buf,
361                                        u32 bits, u32 words)
362 {
363         u32 dr2 = MDR2_BITLEN1(bits) | MDR2_WDLEN1(words);
364 
365         if (tx_buf || (p->master->flags & SPI_MASTER_MUST_TX))
366                 sh_msiof_write(p, TMDR2, dr2);
367         else
368                 sh_msiof_write(p, TMDR2, dr2 | MDR2_GRPMASK1);
369 
370         if (rx_buf)
371                 sh_msiof_write(p, RMDR2, dr2);
372 }
373 
374 static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
375 {
376         sh_msiof_write(p, STR, sh_msiof_read(p, STR));
377 }
378 
379 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
380                                       const void *tx_buf, int words, int fs)
381 {
382         const u8 *buf_8 = tx_buf;
383         int k;
384 
385         for (k = 0; k < words; k++)
386                 sh_msiof_write(p, TFDR, buf_8[k] << fs);
387 }
388 
389 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
390                                        const void *tx_buf, int words, int fs)
391 {
392         const u16 *buf_16 = tx_buf;
393         int k;
394 
395         for (k = 0; k < words; k++)
396                 sh_msiof_write(p, TFDR, buf_16[k] << fs);
397 }
398 
399 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
400                                         const void *tx_buf, int words, int fs)
401 {
402         const u16 *buf_16 = tx_buf;
403         int k;
404 
405         for (k = 0; k < words; k++)
406                 sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
407 }
408 
409 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
410                                        const void *tx_buf, int words, int fs)
411 {
412         const u32 *buf_32 = tx_buf;
413         int k;
414 
415         for (k = 0; k < words; k++)
416                 sh_msiof_write(p, TFDR, buf_32[k] << fs);
417 }
418 
419 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
420                                         const void *tx_buf, int words, int fs)
421 {
422         const u32 *buf_32 = tx_buf;
423         int k;
424 
425         for (k = 0; k < words; k++)
426                 sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
427 }
428 
429 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
430                                         const void *tx_buf, int words, int fs)
431 {
432         const u32 *buf_32 = tx_buf;
433         int k;
434 
435         for (k = 0; k < words; k++)
436                 sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
437 }
438 
439 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
440                                          const void *tx_buf, int words, int fs)
441 {
442         const u32 *buf_32 = tx_buf;
443         int k;
444 
445         for (k = 0; k < words; k++)
446                 sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
447 }
448 
449 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
450                                      void *rx_buf, int words, int fs)
451 {
452         u8 *buf_8 = rx_buf;
453         int k;
454 
455         for (k = 0; k < words; k++)
456                 buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
457 }
458 
459 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
460                                       void *rx_buf, int words, int fs)
461 {
462         u16 *buf_16 = rx_buf;
463         int k;
464 
465         for (k = 0; k < words; k++)
466                 buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
467 }
468 
469 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
470                                        void *rx_buf, int words, int fs)
471 {
472         u16 *buf_16 = rx_buf;
473         int k;
474 
475         for (k = 0; k < words; k++)
476                 put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
477 }
478 
479 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
480                                       void *rx_buf, int words, int fs)
481 {
482         u32 *buf_32 = rx_buf;
483         int k;
484 
485         for (k = 0; k < words; k++)
486                 buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
487 }
488 
489 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
490                                        void *rx_buf, int words, int fs)
491 {
492         u32 *buf_32 = rx_buf;
493         int k;
494 
495         for (k = 0; k < words; k++)
496                 put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
497 }
498 
499 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
500                                        void *rx_buf, int words, int fs)
501 {
502         u32 *buf_32 = rx_buf;
503         int k;
504 
505         for (k = 0; k < words; k++)
506                 buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
507 }
508 
509 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
510                                        void *rx_buf, int words, int fs)
511 {
512         u32 *buf_32 = rx_buf;
513         int k;
514 
515         for (k = 0; k < words; k++)
516                 put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
517 }
518 
519 static int sh_msiof_spi_setup(struct spi_device *spi)
520 {
521         struct device_node      *np = spi->master->dev.of_node;
522         struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
523 
524         pm_runtime_get_sync(&p->pdev->dev);
525 
526         if (!np) {
527                 /*
528                  * Use spi->controller_data for CS (same strategy as spi_gpio),
529                  * if any. otherwise let HW control CS
530                  */
531                 spi->cs_gpio = (uintptr_t)spi->controller_data;
532         }
533 
534         /* Configure pins before deasserting CS */
535         sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
536                                   !!(spi->mode & SPI_CPHA),
537                                   !!(spi->mode & SPI_3WIRE),
538                                   !!(spi->mode & SPI_LSB_FIRST),
539                                   !!(spi->mode & SPI_CS_HIGH));
540 
541         if (spi->cs_gpio >= 0)
542                 gpio_set_value(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
543 
544 
545         pm_runtime_put(&p->pdev->dev);
546 
547         return 0;
548 }
549 
550 static int sh_msiof_prepare_message(struct spi_master *master,
551                                     struct spi_message *msg)
552 {
553         struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
554         const struct spi_device *spi = msg->spi;
555 
556         /* Configure pins before asserting CS */
557         sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
558                                   !!(spi->mode & SPI_CPHA),
559                                   !!(spi->mode & SPI_3WIRE),
560                                   !!(spi->mode & SPI_LSB_FIRST),
561                                   !!(spi->mode & SPI_CS_HIGH));
562         return 0;
563 }
564 
565 static int sh_msiof_spi_start(struct sh_msiof_spi_priv *p, void *rx_buf)
566 {
567         int ret;
568 
569         /* setup clock and rx/tx signals */
570         ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
571         if (rx_buf && !ret)
572                 ret = sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
573         if (!ret)
574                 ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
575 
576         /* start by setting frame bit */
577         if (!ret)
578                 ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
579 
580         return ret;
581 }
582 
583 static int sh_msiof_spi_stop(struct sh_msiof_spi_priv *p, void *rx_buf)
584 {
585         int ret;
586 
587         /* shut down frame, rx/tx and clock signals */
588         ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
589         if (!ret)
590                 ret = sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
591         if (rx_buf && !ret)
592                 ret = sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
593         if (!ret)
594                 ret = sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
595 
596         return ret;
597 }
598 
599 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
600                                   void (*tx_fifo)(struct sh_msiof_spi_priv *,
601                                                   const void *, int, int),
602                                   void (*rx_fifo)(struct sh_msiof_spi_priv *,
603                                                   void *, int, int),
604                                   const void *tx_buf, void *rx_buf,
605                                   int words, int bits)
606 {
607         int fifo_shift;
608         int ret;
609 
610         /* limit maximum word transfer to rx/tx fifo size */
611         if (tx_buf)
612                 words = min_t(int, words, p->tx_fifo_size);
613         if (rx_buf)
614                 words = min_t(int, words, p->rx_fifo_size);
615 
616         /* the fifo contents need shifting */
617         fifo_shift = 32 - bits;
618 
619         /* default FIFO watermarks for PIO */
620         sh_msiof_write(p, FCTR, 0);
621 
622         /* setup msiof transfer mode registers */
623         sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
624         sh_msiof_write(p, IER, IER_TEOFE | IER_REOFE);
625 
626         /* write tx fifo */
627         if (tx_buf)
628                 tx_fifo(p, tx_buf, words, fifo_shift);
629 
630         reinit_completion(&p->done);
631 
632         ret = sh_msiof_spi_start(p, rx_buf);
633         if (ret) {
634                 dev_err(&p->pdev->dev, "failed to start hardware\n");
635                 goto stop_ier;
636         }
637 
638         /* wait for tx fifo to be emptied / rx fifo to be filled */
639         if (!wait_for_completion_timeout(&p->done, HZ)) {
640                 dev_err(&p->pdev->dev, "PIO timeout\n");
641                 ret = -ETIMEDOUT;
642                 goto stop_reset;
643         }
644 
645         /* read rx fifo */
646         if (rx_buf)
647                 rx_fifo(p, rx_buf, words, fifo_shift);
648 
649         /* clear status bits */
650         sh_msiof_reset_str(p);
651 
652         ret = sh_msiof_spi_stop(p, rx_buf);
653         if (ret) {
654                 dev_err(&p->pdev->dev, "failed to shut down hardware\n");
655                 return ret;
656         }
657 
658         return words;
659 
660 stop_reset:
661         sh_msiof_reset_str(p);
662         sh_msiof_spi_stop(p, rx_buf);
663 stop_ier:
664         sh_msiof_write(p, IER, 0);
665         return ret;
666 }
667 
668 static void sh_msiof_dma_complete(void *arg)
669 {
670         struct sh_msiof_spi_priv *p = arg;
671 
672         sh_msiof_write(p, IER, 0);
673         complete(&p->done);
674 }
675 
676 static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
677                              void *rx, unsigned int len)
678 {
679         u32 ier_bits = 0;
680         struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
681         dma_cookie_t cookie;
682         int ret;
683 
684         /* First prepare and submit the DMA request(s), as this may fail */
685         if (rx) {
686                 ier_bits |= IER_RDREQE | IER_RDMAE;
687                 desc_rx = dmaengine_prep_slave_single(p->master->dma_rx,
688                                         p->rx_dma_addr, len, DMA_FROM_DEVICE,
689                                         DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
690                 if (!desc_rx)
691                         return -EAGAIN;
692 
693                 desc_rx->callback = sh_msiof_dma_complete;
694                 desc_rx->callback_param = p;
695                 cookie = dmaengine_submit(desc_rx);
696                 if (dma_submit_error(cookie))
697                         return cookie;
698         }
699 
700         if (tx) {
701                 ier_bits |= IER_TDREQE | IER_TDMAE;
702                 dma_sync_single_for_device(p->master->dma_tx->device->dev,
703                                            p->tx_dma_addr, len, DMA_TO_DEVICE);
704                 desc_tx = dmaengine_prep_slave_single(p->master->dma_tx,
705                                         p->tx_dma_addr, len, DMA_TO_DEVICE,
706                                         DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
707                 if (!desc_tx) {
708                         ret = -EAGAIN;
709                         goto no_dma_tx;
710                 }
711 
712                 if (rx) {
713                         /* No callback */
714                         desc_tx->callback = NULL;
715                 } else {
716                         desc_tx->callback = sh_msiof_dma_complete;
717                         desc_tx->callback_param = p;
718                 }
719                 cookie = dmaengine_submit(desc_tx);
720                 if (dma_submit_error(cookie)) {
721                         ret = cookie;
722                         goto no_dma_tx;
723                 }
724         }
725 
726         /* 1 stage FIFO watermarks for DMA */
727         sh_msiof_write(p, FCTR, FCTR_TFWM_1 | FCTR_RFWM_1);
728 
729         /* setup msiof transfer mode registers (32-bit words) */
730         sh_msiof_spi_set_mode_regs(p, tx, rx, 32, len / 4);
731 
732         sh_msiof_write(p, IER, ier_bits);
733 
734         reinit_completion(&p->done);
735 
736         /* Now start DMA */
737         if (rx)
738                 dma_async_issue_pending(p->master->dma_rx);
739         if (tx)
740                 dma_async_issue_pending(p->master->dma_tx);
741 
742         ret = sh_msiof_spi_start(p, rx);
743         if (ret) {
744                 dev_err(&p->pdev->dev, "failed to start hardware\n");
745                 goto stop_dma;
746         }
747 
748         /* wait for tx fifo to be emptied / rx fifo to be filled */
749         if (!wait_for_completion_timeout(&p->done, HZ)) {
750                 dev_err(&p->pdev->dev, "DMA timeout\n");
751                 ret = -ETIMEDOUT;
752                 goto stop_reset;
753         }
754 
755         /* clear status bits */
756         sh_msiof_reset_str(p);
757 
758         ret = sh_msiof_spi_stop(p, rx);
759         if (ret) {
760                 dev_err(&p->pdev->dev, "failed to shut down hardware\n");
761                 return ret;
762         }
763 
764         if (rx)
765                 dma_sync_single_for_cpu(p->master->dma_rx->device->dev,
766                                         p->rx_dma_addr, len,
767                                         DMA_FROM_DEVICE);
768 
769         return 0;
770 
771 stop_reset:
772         sh_msiof_reset_str(p);
773         sh_msiof_spi_stop(p, rx);
774 stop_dma:
775         if (tx)
776                 dmaengine_terminate_all(p->master->dma_tx);
777 no_dma_tx:
778         if (rx)
779                 dmaengine_terminate_all(p->master->dma_rx);
780         sh_msiof_write(p, IER, 0);
781         return ret;
782 }
783 
784 static void copy_bswap32(u32 *dst, const u32 *src, unsigned int words)
785 {
786         /* src or dst can be unaligned, but not both */
787         if ((unsigned long)src & 3) {
788                 while (words--) {
789                         *dst++ = swab32(get_unaligned(src));
790                         src++;
791                 }
792         } else if ((unsigned long)dst & 3) {
793                 while (words--) {
794                         put_unaligned(swab32(*src++), dst);
795                         dst++;
796                 }
797         } else {
798                 while (words--)
799                         *dst++ = swab32(*src++);
800         }
801 }
802 
803 static void copy_wswap32(u32 *dst, const u32 *src, unsigned int words)
804 {
805         /* src or dst can be unaligned, but not both */
806         if ((unsigned long)src & 3) {
807                 while (words--) {
808                         *dst++ = swahw32(get_unaligned(src));
809                         src++;
810                 }
811         } else if ((unsigned long)dst & 3) {
812                 while (words--) {
813                         put_unaligned(swahw32(*src++), dst);
814                         dst++;
815                 }
816         } else {
817                 while (words--)
818                         *dst++ = swahw32(*src++);
819         }
820 }
821 
822 static void copy_plain32(u32 *dst, const u32 *src, unsigned int words)
823 {
824         memcpy(dst, src, words * 4);
825 }
826 
827 static int sh_msiof_transfer_one(struct spi_master *master,
828                                  struct spi_device *spi,
829                                  struct spi_transfer *t)
830 {
831         struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
832         void (*copy32)(u32 *, const u32 *, unsigned int);
833         void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
834         void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
835         const void *tx_buf = t->tx_buf;
836         void *rx_buf = t->rx_buf;
837         unsigned int len = t->len;
838         unsigned int bits = t->bits_per_word;
839         unsigned int bytes_per_word;
840         unsigned int words;
841         int n;
842         bool swab;
843         int ret;
844 
845         /* setup clocks (clock already enabled in chipselect()) */
846         sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);
847 
848         while (master->dma_tx && len > 15) {
849                 /*
850                  *  DMA supports 32-bit words only, hence pack 8-bit and 16-bit
851                  *  words, with byte resp. word swapping.
852                  */
853                 unsigned int l = 0;
854 
855                 if (tx_buf)
856                         l = min(len, p->tx_fifo_size * 4);
857                 if (rx_buf)
858                         l = min(len, p->rx_fifo_size * 4);
859 
860                 if (bits <= 8) {
861                         if (l & 3)
862                                 break;
863                         copy32 = copy_bswap32;
864                 } else if (bits <= 16) {
865                         if (l & 1)
866                                 break;
867                         copy32 = copy_wswap32;
868                 } else {
869                         copy32 = copy_plain32;
870                 }
871 
872                 if (tx_buf)
873                         copy32(p->tx_dma_page, tx_buf, l / 4);
874 
875                 ret = sh_msiof_dma_once(p, tx_buf, rx_buf, l);
876                 if (ret == -EAGAIN) {
877                         pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
878                                      dev_driver_string(&p->pdev->dev),
879                                      dev_name(&p->pdev->dev));
880                         break;
881                 }
882                 if (ret)
883                         return ret;
884 
885                 if (rx_buf) {
886                         copy32(rx_buf, p->rx_dma_page, l / 4);
887                         rx_buf += l;
888                 }
889                 if (tx_buf)
890                         tx_buf += l;
891 
892                 len -= l;
893                 if (!len)
894                         return 0;
895         }
896 
897         if (bits <= 8 && len > 15 && !(len & 3)) {
898                 bits = 32;
899                 swab = true;
900         } else {
901                 swab = false;
902         }
903 
904         /* setup bytes per word and fifo read/write functions */
905         if (bits <= 8) {
906                 bytes_per_word = 1;
907                 tx_fifo = sh_msiof_spi_write_fifo_8;
908                 rx_fifo = sh_msiof_spi_read_fifo_8;
909         } else if (bits <= 16) {
910                 bytes_per_word = 2;
911                 if ((unsigned long)tx_buf & 0x01)
912                         tx_fifo = sh_msiof_spi_write_fifo_16u;
913                 else
914                         tx_fifo = sh_msiof_spi_write_fifo_16;
915 
916                 if ((unsigned long)rx_buf & 0x01)
917                         rx_fifo = sh_msiof_spi_read_fifo_16u;
918                 else
919                         rx_fifo = sh_msiof_spi_read_fifo_16;
920         } else if (swab) {
921                 bytes_per_word = 4;
922                 if ((unsigned long)tx_buf & 0x03)
923                         tx_fifo = sh_msiof_spi_write_fifo_s32u;
924                 else
925                         tx_fifo = sh_msiof_spi_write_fifo_s32;
926 
927                 if ((unsigned long)rx_buf & 0x03)
928                         rx_fifo = sh_msiof_spi_read_fifo_s32u;
929                 else
930                         rx_fifo = sh_msiof_spi_read_fifo_s32;
931         } else {
932                 bytes_per_word = 4;
933                 if ((unsigned long)tx_buf & 0x03)
934                         tx_fifo = sh_msiof_spi_write_fifo_32u;
935                 else
936                         tx_fifo = sh_msiof_spi_write_fifo_32;
937 
938                 if ((unsigned long)rx_buf & 0x03)
939                         rx_fifo = sh_msiof_spi_read_fifo_32u;
940                 else
941                         rx_fifo = sh_msiof_spi_read_fifo_32;
942         }
943 
944         /* transfer in fifo sized chunks */
945         words = len / bytes_per_word;
946 
947         while (words > 0) {
948                 n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo, tx_buf, rx_buf,
949                                            words, bits);
950                 if (n < 0)
951                         return n;
952 
953                 if (tx_buf)
954                         tx_buf += n * bytes_per_word;
955                 if (rx_buf)
956                         rx_buf += n * bytes_per_word;
957                 words -= n;
958         }
959 
960         return 0;
961 }
962 
963 static const struct sh_msiof_chipdata sh_data = {
964         .tx_fifo_size = 64,
965         .rx_fifo_size = 64,
966         .master_flags = 0,
967 };
968 
969 static const struct sh_msiof_chipdata r8a779x_data = {
970         .tx_fifo_size = 64,
971         .rx_fifo_size = 64,
972         .master_flags = SPI_MASTER_MUST_TX,
973 };
974 
975 static const struct of_device_id sh_msiof_match[] = {
976         { .compatible = "renesas,sh-msiof",        .data = &sh_data },
977         { .compatible = "renesas,sh-mobile-msiof", .data = &sh_data },
978         { .compatible = "renesas,msiof-r8a7790",   .data = &r8a779x_data },
979         { .compatible = "renesas,msiof-r8a7791",   .data = &r8a779x_data },
980         { .compatible = "renesas,msiof-r8a7792",   .data = &r8a779x_data },
981         { .compatible = "renesas,msiof-r8a7793",   .data = &r8a779x_data },
982         { .compatible = "renesas,msiof-r8a7794",   .data = &r8a779x_data },
983         {},
984 };
985 MODULE_DEVICE_TABLE(of, sh_msiof_match);
986 
987 #ifdef CONFIG_OF
988 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
989 {
990         struct sh_msiof_spi_info *info;
991         struct device_node *np = dev->of_node;
992         u32 num_cs = 1;
993 
994         info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
995         if (!info)
996                 return NULL;
997 
998         /* Parse the MSIOF properties */
999         of_property_read_u32(np, "num-cs", &num_cs);
1000         of_property_read_u32(np, "renesas,tx-fifo-size",
1001                                         &info->tx_fifo_override);
1002         of_property_read_u32(np, "renesas,rx-fifo-size",
1003                                         &info->rx_fifo_override);
1004         of_property_read_u32(np, "renesas,dtdl", &info->dtdl);
1005         of_property_read_u32(np, "renesas,syncdl", &info->syncdl);
1006 
1007         info->num_chipselect = num_cs;
1008 
1009         return info;
1010 }
1011 #else
1012 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
1013 {
1014         return NULL;
1015 }
1016 #endif
1017 
1018 static struct dma_chan *sh_msiof_request_dma_chan(struct device *dev,
1019         enum dma_transfer_direction dir, unsigned int id, dma_addr_t port_addr)
1020 {
1021         dma_cap_mask_t mask;
1022         struct dma_chan *chan;
1023         struct dma_slave_config cfg;
1024         int ret;
1025 
1026         dma_cap_zero(mask);
1027         dma_cap_set(DMA_SLAVE, mask);
1028 
1029         chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
1030                                 (void *)(unsigned long)id, dev,
1031                                 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1032         if (!chan) {
1033                 dev_warn(dev, "dma_request_slave_channel_compat failed\n");
1034                 return NULL;
1035         }
1036 
1037         memset(&cfg, 0, sizeof(cfg));
1038         cfg.direction = dir;
1039         if (dir == DMA_MEM_TO_DEV) {
1040                 cfg.dst_addr = port_addr;
1041                 cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1042         } else {
1043                 cfg.src_addr = port_addr;
1044                 cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1045         }
1046 
1047         ret = dmaengine_slave_config(chan, &cfg);
1048         if (ret) {
1049                 dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
1050                 dma_release_channel(chan);
1051                 return NULL;
1052         }
1053 
1054         return chan;
1055 }
1056 
1057 static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p)
1058 {
1059         struct platform_device *pdev = p->pdev;
1060         struct device *dev = &pdev->dev;
1061         const struct sh_msiof_spi_info *info = dev_get_platdata(dev);
1062         unsigned int dma_tx_id, dma_rx_id;
1063         const struct resource *res;
1064         struct spi_master *master;
1065         struct device *tx_dev, *rx_dev;
1066 
1067         if (dev->of_node) {
1068                 /* In the OF case we will get the slave IDs from the DT */
1069                 dma_tx_id = 0;
1070                 dma_rx_id = 0;
1071         } else if (info && info->dma_tx_id && info->dma_rx_id) {
1072                 dma_tx_id = info->dma_tx_id;
1073                 dma_rx_id = info->dma_rx_id;
1074         } else {
1075                 /* The driver assumes no error */
1076                 return 0;
1077         }
1078 
1079         /* The DMA engine uses the second register set, if present */
1080         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1081         if (!res)
1082                 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1083 
1084         master = p->master;
1085         master->dma_tx = sh_msiof_request_dma_chan(dev, DMA_MEM_TO_DEV,
1086                                                    dma_tx_id,
1087                                                    res->start + TFDR);
1088         if (!master->dma_tx)
1089                 return -ENODEV;
1090 
1091         master->dma_rx = sh_msiof_request_dma_chan(dev, DMA_DEV_TO_MEM,
1092                                                    dma_rx_id,
1093                                                    res->start + RFDR);
1094         if (!master->dma_rx)
1095                 goto free_tx_chan;
1096 
1097         p->tx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
1098         if (!p->tx_dma_page)
1099                 goto free_rx_chan;
1100 
1101         p->rx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
1102         if (!p->rx_dma_page)
1103                 goto free_tx_page;
1104 
1105         tx_dev = master->dma_tx->device->dev;
1106         p->tx_dma_addr = dma_map_single(tx_dev, p->tx_dma_page, PAGE_SIZE,
1107                                         DMA_TO_DEVICE);
1108         if (dma_mapping_error(tx_dev, p->tx_dma_addr))
1109                 goto free_rx_page;
1110 
1111         rx_dev = master->dma_rx->device->dev;
1112         p->rx_dma_addr = dma_map_single(rx_dev, p->rx_dma_page, PAGE_SIZE,
1113                                         DMA_FROM_DEVICE);
1114         if (dma_mapping_error(rx_dev, p->rx_dma_addr))
1115                 goto unmap_tx_page;
1116 
1117         dev_info(dev, "DMA available");
1118         return 0;
1119 
1120 unmap_tx_page:
1121         dma_unmap_single(tx_dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
1122 free_rx_page:
1123         free_page((unsigned long)p->rx_dma_page);
1124 free_tx_page:
1125         free_page((unsigned long)p->tx_dma_page);
1126 free_rx_chan:
1127         dma_release_channel(master->dma_rx);
1128 free_tx_chan:
1129         dma_release_channel(master->dma_tx);
1130         master->dma_tx = NULL;
1131         return -ENODEV;
1132 }
1133 
1134 static void sh_msiof_release_dma(struct sh_msiof_spi_priv *p)
1135 {
1136         struct spi_master *master = p->master;
1137         struct device *dev;
1138 
1139         if (!master->dma_tx)
1140                 return;
1141 
1142         dev = &p->pdev->dev;
1143         dma_unmap_single(master->dma_rx->device->dev, p->rx_dma_addr,
1144                          PAGE_SIZE, DMA_FROM_DEVICE);
1145         dma_unmap_single(master->dma_tx->device->dev, p->tx_dma_addr,
1146                          PAGE_SIZE, DMA_TO_DEVICE);
1147         free_page((unsigned long)p->rx_dma_page);
1148         free_page((unsigned long)p->tx_dma_page);
1149         dma_release_channel(master->dma_rx);
1150         dma_release_channel(master->dma_tx);
1151 }
1152 
1153 static int sh_msiof_spi_probe(struct platform_device *pdev)
1154 {
1155         struct resource *r;
1156         struct spi_master *master;
1157         const struct sh_msiof_chipdata *chipdata;
1158         const struct of_device_id *of_id;
1159         struct sh_msiof_spi_priv *p;
1160         int i;
1161         int ret;
1162 
1163         master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv));
1164         if (master == NULL) {
1165                 dev_err(&pdev->dev, "failed to allocate spi master\n");
1166                 return -ENOMEM;
1167         }
1168 
1169         p = spi_master_get_devdata(master);
1170 
1171         platform_set_drvdata(pdev, p);
1172         p->master = master;
1173 
1174         of_id = of_match_device(sh_msiof_match, &pdev->dev);
1175         if (of_id) {
1176                 chipdata = of_id->data;
1177                 p->info = sh_msiof_spi_parse_dt(&pdev->dev);
1178         } else {
1179                 chipdata = (const void *)pdev->id_entry->driver_data;
1180                 p->info = dev_get_platdata(&pdev->dev);
1181         }
1182 
1183         if (!p->info) {
1184                 dev_err(&pdev->dev, "failed to obtain device info\n");
1185                 ret = -ENXIO;
1186                 goto err1;
1187         }
1188 
1189         init_completion(&p->done);
1190 
1191         p->clk = devm_clk_get(&pdev->dev, NULL);
1192         if (IS_ERR(p->clk)) {
1193                 dev_err(&pdev->dev, "cannot get clock\n");
1194                 ret = PTR_ERR(p->clk);
1195                 goto err1;
1196         }
1197 
1198         i = platform_get_irq(pdev, 0);
1199         if (i < 0) {
1200                 dev_err(&pdev->dev, "cannot get platform IRQ\n");
1201                 ret = -ENOENT;
1202                 goto err1;
1203         }
1204 
1205         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1206         p->mapbase = devm_ioremap_resource(&pdev->dev, r);
1207         if (IS_ERR(p->mapbase)) {
1208                 ret = PTR_ERR(p->mapbase);
1209                 goto err1;
1210         }
1211 
1212         ret = devm_request_irq(&pdev->dev, i, sh_msiof_spi_irq, 0,
1213                                dev_name(&pdev->dev), p);
1214         if (ret) {
1215                 dev_err(&pdev->dev, "unable to request irq\n");
1216                 goto err1;
1217         }
1218 
1219         p->pdev = pdev;
1220         pm_runtime_enable(&pdev->dev);
1221 
1222         /* Platform data may override FIFO sizes */
1223         p->tx_fifo_size = chipdata->tx_fifo_size;
1224         p->rx_fifo_size = chipdata->rx_fifo_size;
1225         if (p->info->tx_fifo_override)
1226                 p->tx_fifo_size = p->info->tx_fifo_override;
1227         if (p->info->rx_fifo_override)
1228                 p->rx_fifo_size = p->info->rx_fifo_override;
1229 
1230         /* init master code */
1231         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1232         master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
1233         master->flags = chipdata->master_flags;
1234         master->bus_num = pdev->id;
1235         master->dev.of_node = pdev->dev.of_node;
1236         master->num_chipselect = p->info->num_chipselect;
1237         master->setup = sh_msiof_spi_setup;
1238         master->prepare_message = sh_msiof_prepare_message;
1239         master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
1240         master->auto_runtime_pm = true;
1241         master->transfer_one = sh_msiof_transfer_one;
1242 
1243         ret = sh_msiof_request_dma(p);
1244         if (ret < 0)
1245                 dev_warn(&pdev->dev, "DMA not available, using PIO\n");
1246 
1247         ret = devm_spi_register_master(&pdev->dev, master);
1248         if (ret < 0) {
1249                 dev_err(&pdev->dev, "spi_register_master error.\n");
1250                 goto err2;
1251         }
1252 
1253         return 0;
1254 
1255  err2:
1256         sh_msiof_release_dma(p);
1257         pm_runtime_disable(&pdev->dev);
1258  err1:
1259         spi_master_put(master);
1260         return ret;
1261 }
1262 
1263 static int sh_msiof_spi_remove(struct platform_device *pdev)
1264 {
1265         struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
1266 
1267         sh_msiof_release_dma(p);
1268         pm_runtime_disable(&pdev->dev);
1269         return 0;
1270 }
1271 
1272 static const struct platform_device_id spi_driver_ids[] = {
1273         { "spi_sh_msiof",       (kernel_ulong_t)&sh_data },
1274         {},
1275 };
1276 MODULE_DEVICE_TABLE(platform, spi_driver_ids);
1277 
1278 static struct platform_driver sh_msiof_spi_drv = {
1279         .probe          = sh_msiof_spi_probe,
1280         .remove         = sh_msiof_spi_remove,
1281         .id_table       = spi_driver_ids,
1282         .driver         = {
1283                 .name           = "spi_sh_msiof",
1284                 .of_match_table = of_match_ptr(sh_msiof_match),
1285         },
1286 };
1287 module_platform_driver(sh_msiof_spi_drv);
1288 
1289 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
1290 MODULE_AUTHOR("Magnus Damm");
1291 MODULE_LICENSE("GPL v2");
1292 MODULE_ALIAS("platform:spi_sh_msiof");
1293 

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