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1 | /* | |
2 | * au1550 psc spi controller driver | |
3 | * may work also with au1200, au1210, au1250 | |
4 | * will not work on au1000, au1100 and au1500 (no full spi controller there) | |
5 | * | |
6 | * Copyright (c) 2006 ATRON electronic GmbH | |
7 | * Author: Jan Nikitenko <jan.nikitenko@gmail.com> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to the Free Software | |
21 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
22 | */ | |
23 | ||
24 | #include <linux/init.h> | |
25 | #include <linux/interrupt.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/errno.h> | |
28 | #include <linux/module.h> | |
29 | #include <linux/device.h> | |
30 | #include <linux/platform_device.h> | |
31 | #include <linux/resource.h> | |
32 | #include <linux/spi/spi.h> | |
33 | #include <linux/spi/spi_bitbang.h> | |
34 | #include <linux/dma-mapping.h> | |
35 | #include <linux/completion.h> | |
36 | #include <asm/mach-au1x00/au1000.h> | |
37 | #include <asm/mach-au1x00/au1xxx_psc.h> | |
38 | #include <asm/mach-au1x00/au1xxx_dbdma.h> | |
39 | ||
40 | #include <asm/mach-au1x00/au1550_spi.h> | |
41 | ||
42 | static unsigned usedma = 1; | |
43 | module_param(usedma, uint, 0644); | |
44 | ||
45 | /* | |
46 | #define AU1550_SPI_DEBUG_LOOPBACK | |
47 | */ | |
48 | ||
49 | ||
50 | #define AU1550_SPI_DBDMA_DESCRIPTORS 1 | |
51 | #define AU1550_SPI_DMA_RXTMP_MINSIZE 2048U | |
52 | ||
53 | struct au1550_spi { | |
54 | struct spi_bitbang bitbang; | |
55 | ||
56 | volatile psc_spi_t __iomem *regs; | |
57 | int irq; | |
58 | ||
59 | unsigned len; | |
60 | unsigned tx_count; | |
61 | unsigned rx_count; | |
62 | const u8 *tx; | |
63 | u8 *rx; | |
64 | ||
65 | void (*rx_word)(struct au1550_spi *hw); | |
66 | void (*tx_word)(struct au1550_spi *hw); | |
67 | int (*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t); | |
68 | irqreturn_t (*irq_callback)(struct au1550_spi *hw); | |
69 | ||
70 | struct completion master_done; | |
71 | ||
72 | unsigned usedma; | |
73 | u32 dma_tx_id; | |
74 | u32 dma_rx_id; | |
75 | u32 dma_tx_ch; | |
76 | u32 dma_rx_ch; | |
77 | ||
78 | u8 *dma_rx_tmpbuf; | |
79 | unsigned dma_rx_tmpbuf_size; | |
80 | u32 dma_rx_tmpbuf_addr; | |
81 | ||
82 | struct spi_master *master; | |
83 | struct device *dev; | |
84 | struct au1550_spi_info *pdata; | |
85 | struct resource *ioarea; | |
86 | }; | |
87 | ||
88 | ||
89 | /* we use an 8-bit memory device for dma transfers to/from spi fifo */ | |
90 | static dbdev_tab_t au1550_spi_mem_dbdev = | |
91 | { | |
92 | .dev_id = DBDMA_MEM_CHAN, | |
93 | .dev_flags = DEV_FLAGS_ANYUSE|DEV_FLAGS_SYNC, | |
94 | .dev_tsize = 0, | |
95 | .dev_devwidth = 8, | |
96 | .dev_physaddr = 0x00000000, | |
97 | .dev_intlevel = 0, | |
98 | .dev_intpolarity = 0 | |
99 | }; | |
100 | ||
101 | static int ddma_memid; /* id to above mem dma device */ | |
102 | ||
103 | static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw); | |
104 | ||
105 | ||
106 | /* | |
107 | * compute BRG and DIV bits to setup spi clock based on main input clock rate | |
108 | * that was specified in platform data structure | |
109 | * according to au1550 datasheet: | |
110 | * psc_tempclk = psc_mainclk / (2 << DIV) | |
111 | * spiclk = psc_tempclk / (2 * (BRG + 1)) | |
112 | * BRG valid range is 4..63 | |
113 | * DIV valid range is 0..3 | |
114 | */ | |
115 | static u32 au1550_spi_baudcfg(struct au1550_spi *hw, unsigned speed_hz) | |
116 | { | |
117 | u32 mainclk_hz = hw->pdata->mainclk_hz; | |
118 | u32 div, brg; | |
119 | ||
120 | for (div = 0; div < 4; div++) { | |
121 | brg = mainclk_hz / speed_hz / (4 << div); | |
122 | /* now we have BRG+1 in brg, so count with that */ | |
123 | if (brg < (4 + 1)) { | |
124 | brg = (4 + 1); /* speed_hz too big */ | |
125 | break; /* set lowest brg (div is == 0) */ | |
126 | } | |
127 | if (brg <= (63 + 1)) | |
128 | break; /* we have valid brg and div */ | |
129 | } | |
130 | if (div == 4) { | |
131 | div = 3; /* speed_hz too small */ | |
132 | brg = (63 + 1); /* set highest brg and div */ | |
133 | } | |
134 | brg--; | |
135 | return PSC_SPICFG_SET_BAUD(brg) | PSC_SPICFG_SET_DIV(div); | |
136 | } | |
137 | ||
138 | static inline void au1550_spi_mask_ack_all(struct au1550_spi *hw) | |
139 | { | |
140 | hw->regs->psc_spimsk = | |
141 | PSC_SPIMSK_MM | PSC_SPIMSK_RR | PSC_SPIMSK_RO | |
142 | | PSC_SPIMSK_RU | PSC_SPIMSK_TR | PSC_SPIMSK_TO | |
143 | | PSC_SPIMSK_TU | PSC_SPIMSK_SD | PSC_SPIMSK_MD; | |
144 | au_sync(); | |
145 | ||
146 | hw->regs->psc_spievent = | |
147 | PSC_SPIEVNT_MM | PSC_SPIEVNT_RR | PSC_SPIEVNT_RO | |
148 | | PSC_SPIEVNT_RU | PSC_SPIEVNT_TR | PSC_SPIEVNT_TO | |
149 | | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD | PSC_SPIEVNT_MD; | |
150 | au_sync(); | |
151 | } | |
152 | ||
153 | static void au1550_spi_reset_fifos(struct au1550_spi *hw) | |
154 | { | |
155 | u32 pcr; | |
156 | ||
157 | hw->regs->psc_spipcr = PSC_SPIPCR_RC | PSC_SPIPCR_TC; | |
158 | au_sync(); | |
159 | do { | |
160 | pcr = hw->regs->psc_spipcr; | |
161 | au_sync(); | |
162 | } while (pcr != 0); | |
163 | } | |
164 | ||
165 | /* | |
166 | * dma transfers are used for the most common spi word size of 8-bits | |
167 | * we cannot easily change already set up dma channels' width, so if we wanted | |
168 | * dma support for more than 8-bit words (up to 24 bits), we would need to | |
169 | * setup dma channels from scratch on each spi transfer, based on bits_per_word | |
170 | * instead we have pre set up 8 bit dma channels supporting spi 4 to 8 bits | |
171 | * transfers, and 9 to 24 bits spi transfers will be done in pio irq based mode | |
172 | * callbacks to handle dma or pio are set up in au1550_spi_bits_handlers_set() | |
173 | */ | |
174 | static void au1550_spi_chipsel(struct spi_device *spi, int value) | |
175 | { | |
176 | struct au1550_spi *hw = spi_master_get_devdata(spi->master); | |
177 | unsigned cspol = spi->mode & SPI_CS_HIGH ? 1 : 0; | |
178 | u32 cfg, stat; | |
179 | ||
180 | switch (value) { | |
181 | case BITBANG_CS_INACTIVE: | |
182 | if (hw->pdata->deactivate_cs) | |
183 | hw->pdata->deactivate_cs(hw->pdata, spi->chip_select, | |
184 | cspol); | |
185 | break; | |
186 | ||
187 | case BITBANG_CS_ACTIVE: | |
188 | au1550_spi_bits_handlers_set(hw, spi->bits_per_word); | |
189 | ||
190 | cfg = hw->regs->psc_spicfg; | |
191 | au_sync(); | |
192 | hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE; | |
193 | au_sync(); | |
194 | ||
195 | if (spi->mode & SPI_CPOL) | |
196 | cfg |= PSC_SPICFG_BI; | |
197 | else | |
198 | cfg &= ~PSC_SPICFG_BI; | |
199 | if (spi->mode & SPI_CPHA) | |
200 | cfg &= ~PSC_SPICFG_CDE; | |
201 | else | |
202 | cfg |= PSC_SPICFG_CDE; | |
203 | ||
204 | if (spi->mode & SPI_LSB_FIRST) | |
205 | cfg |= PSC_SPICFG_MLF; | |
206 | else | |
207 | cfg &= ~PSC_SPICFG_MLF; | |
208 | ||
209 | if (hw->usedma && spi->bits_per_word <= 8) | |
210 | cfg &= ~PSC_SPICFG_DD_DISABLE; | |
211 | else | |
212 | cfg |= PSC_SPICFG_DD_DISABLE; | |
213 | cfg = PSC_SPICFG_CLR_LEN(cfg); | |
214 | cfg |= PSC_SPICFG_SET_LEN(spi->bits_per_word); | |
215 | ||
216 | cfg = PSC_SPICFG_CLR_BAUD(cfg); | |
217 | cfg &= ~PSC_SPICFG_SET_DIV(3); | |
218 | cfg |= au1550_spi_baudcfg(hw, spi->max_speed_hz); | |
219 | ||
220 | hw->regs->psc_spicfg = cfg | PSC_SPICFG_DE_ENABLE; | |
221 | au_sync(); | |
222 | do { | |
223 | stat = hw->regs->psc_spistat; | |
224 | au_sync(); | |
225 | } while ((stat & PSC_SPISTAT_DR) == 0); | |
226 | ||
227 | if (hw->pdata->activate_cs) | |
228 | hw->pdata->activate_cs(hw->pdata, spi->chip_select, | |
229 | cspol); | |
230 | break; | |
231 | } | |
232 | } | |
233 | ||
234 | static int au1550_spi_setupxfer(struct spi_device *spi, struct spi_transfer *t) | |
235 | { | |
236 | struct au1550_spi *hw = spi_master_get_devdata(spi->master); | |
237 | unsigned bpw, hz; | |
238 | u32 cfg, stat; | |
239 | ||
240 | bpw = spi->bits_per_word; | |
241 | hz = spi->max_speed_hz; | |
242 | if (t) { | |
243 | if (t->bits_per_word) | |
244 | bpw = t->bits_per_word; | |
245 | if (t->speed_hz) | |
246 | hz = t->speed_hz; | |
247 | } | |
248 | ||
249 | if (!hz) | |
250 | return -EINVAL; | |
251 | ||
252 | au1550_spi_bits_handlers_set(hw, spi->bits_per_word); | |
253 | ||
254 | cfg = hw->regs->psc_spicfg; | |
255 | au_sync(); | |
256 | hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE; | |
257 | au_sync(); | |
258 | ||
259 | if (hw->usedma && bpw <= 8) | |
260 | cfg &= ~PSC_SPICFG_DD_DISABLE; | |
261 | else | |
262 | cfg |= PSC_SPICFG_DD_DISABLE; | |
263 | cfg = PSC_SPICFG_CLR_LEN(cfg); | |
264 | cfg |= PSC_SPICFG_SET_LEN(bpw); | |
265 | ||
266 | cfg = PSC_SPICFG_CLR_BAUD(cfg); | |
267 | cfg &= ~PSC_SPICFG_SET_DIV(3); | |
268 | cfg |= au1550_spi_baudcfg(hw, hz); | |
269 | ||
270 | hw->regs->psc_spicfg = cfg; | |
271 | au_sync(); | |
272 | ||
273 | if (cfg & PSC_SPICFG_DE_ENABLE) { | |
274 | do { | |
275 | stat = hw->regs->psc_spistat; | |
276 | au_sync(); | |
277 | } while ((stat & PSC_SPISTAT_DR) == 0); | |
278 | } | |
279 | ||
280 | au1550_spi_reset_fifos(hw); | |
281 | au1550_spi_mask_ack_all(hw); | |
282 | return 0; | |
283 | } | |
284 | ||
285 | /* | |
286 | * for dma spi transfers, we have to setup rx channel, otherwise there is | |
287 | * no reliable way how to recognize that spi transfer is done | |
288 | * dma complete callbacks are called before real spi transfer is finished | |
289 | * and if only tx dma channel is set up (and rx fifo overflow event masked) | |
290 | * spi master done event irq is not generated unless rx fifo is empty (emptied) | |
291 | * so we need rx tmp buffer to use for rx dma if user does not provide one | |
292 | */ | |
293 | static int au1550_spi_dma_rxtmp_alloc(struct au1550_spi *hw, unsigned size) | |
294 | { | |
295 | hw->dma_rx_tmpbuf = kmalloc(size, GFP_KERNEL); | |
296 | if (!hw->dma_rx_tmpbuf) | |
297 | return -ENOMEM; | |
298 | hw->dma_rx_tmpbuf_size = size; | |
299 | hw->dma_rx_tmpbuf_addr = dma_map_single(hw->dev, hw->dma_rx_tmpbuf, | |
300 | size, DMA_FROM_DEVICE); | |
301 | if (dma_mapping_error(hw->dev, hw->dma_rx_tmpbuf_addr)) { | |
302 | kfree(hw->dma_rx_tmpbuf); | |
303 | hw->dma_rx_tmpbuf = 0; | |
304 | hw->dma_rx_tmpbuf_size = 0; | |
305 | return -EFAULT; | |
306 | } | |
307 | return 0; | |
308 | } | |
309 | ||
310 | static void au1550_spi_dma_rxtmp_free(struct au1550_spi *hw) | |
311 | { | |
312 | dma_unmap_single(hw->dev, hw->dma_rx_tmpbuf_addr, | |
313 | hw->dma_rx_tmpbuf_size, DMA_FROM_DEVICE); | |
314 | kfree(hw->dma_rx_tmpbuf); | |
315 | hw->dma_rx_tmpbuf = 0; | |
316 | hw->dma_rx_tmpbuf_size = 0; | |
317 | } | |
318 | ||
319 | static int au1550_spi_dma_txrxb(struct spi_device *spi, struct spi_transfer *t) | |
320 | { | |
321 | struct au1550_spi *hw = spi_master_get_devdata(spi->master); | |
322 | dma_addr_t dma_tx_addr; | |
323 | dma_addr_t dma_rx_addr; | |
324 | u32 res; | |
325 | ||
326 | hw->len = t->len; | |
327 | hw->tx_count = 0; | |
328 | hw->rx_count = 0; | |
329 | ||
330 | hw->tx = t->tx_buf; | |
331 | hw->rx = t->rx_buf; | |
332 | dma_tx_addr = t->tx_dma; | |
333 | dma_rx_addr = t->rx_dma; | |
334 | ||
335 | /* | |
336 | * check if buffers are already dma mapped, map them otherwise: | |
337 | * - first map the TX buffer, so cache data gets written to memory | |
338 | * - then map the RX buffer, so that cache entries (with | |
339 | * soon-to-be-stale data) get removed | |
340 | * use rx buffer in place of tx if tx buffer was not provided | |
341 | * use temp rx buffer (preallocated or realloc to fit) for rx dma | |
342 | */ | |
343 | if (t->tx_buf) { | |
344 | if (t->tx_dma == 0) { /* if DMA_ADDR_INVALID, map it */ | |
345 | dma_tx_addr = dma_map_single(hw->dev, | |
346 | (void *)t->tx_buf, | |
347 | t->len, DMA_TO_DEVICE); | |
348 | if (dma_mapping_error(hw->dev, dma_tx_addr)) | |
349 | dev_err(hw->dev, "tx dma map error\n"); | |
350 | } | |
351 | } | |
352 | ||
353 | if (t->rx_buf) { | |
354 | if (t->rx_dma == 0) { /* if DMA_ADDR_INVALID, map it */ | |
355 | dma_rx_addr = dma_map_single(hw->dev, | |
356 | (void *)t->rx_buf, | |
357 | t->len, DMA_FROM_DEVICE); | |
358 | if (dma_mapping_error(hw->dev, dma_rx_addr)) | |
359 | dev_err(hw->dev, "rx dma map error\n"); | |
360 | } | |
361 | } else { | |
362 | if (t->len > hw->dma_rx_tmpbuf_size) { | |
363 | int ret; | |
364 | ||
365 | au1550_spi_dma_rxtmp_free(hw); | |
366 | ret = au1550_spi_dma_rxtmp_alloc(hw, max(t->len, | |
367 | AU1550_SPI_DMA_RXTMP_MINSIZE)); | |
368 | if (ret < 0) | |
369 | return ret; | |
370 | } | |
371 | hw->rx = hw->dma_rx_tmpbuf; | |
372 | dma_rx_addr = hw->dma_rx_tmpbuf_addr; | |
373 | dma_sync_single_for_device(hw->dev, dma_rx_addr, | |
374 | t->len, DMA_FROM_DEVICE); | |
375 | } | |
376 | ||
377 | if (!t->tx_buf) { | |
378 | dma_sync_single_for_device(hw->dev, dma_rx_addr, | |
379 | t->len, DMA_BIDIRECTIONAL); | |
380 | hw->tx = hw->rx; | |
381 | } | |
382 | ||
383 | /* put buffers on the ring */ | |
384 | res = au1xxx_dbdma_put_dest(hw->dma_rx_ch, virt_to_phys(hw->rx), | |
385 | t->len, DDMA_FLAGS_IE); | |
386 | if (!res) | |
387 | dev_err(hw->dev, "rx dma put dest error\n"); | |
388 | ||
389 | res = au1xxx_dbdma_put_source(hw->dma_tx_ch, virt_to_phys(hw->tx), | |
390 | t->len, DDMA_FLAGS_IE); | |
391 | if (!res) | |
392 | dev_err(hw->dev, "tx dma put source error\n"); | |
393 | ||
394 | au1xxx_dbdma_start(hw->dma_rx_ch); | |
395 | au1xxx_dbdma_start(hw->dma_tx_ch); | |
396 | ||
397 | /* by default enable nearly all events interrupt */ | |
398 | hw->regs->psc_spimsk = PSC_SPIMSK_SD; | |
399 | au_sync(); | |
400 | ||
401 | /* start the transfer */ | |
402 | hw->regs->psc_spipcr = PSC_SPIPCR_MS; | |
403 | au_sync(); | |
404 | ||
405 | wait_for_completion(&hw->master_done); | |
406 | ||
407 | au1xxx_dbdma_stop(hw->dma_tx_ch); | |
408 | au1xxx_dbdma_stop(hw->dma_rx_ch); | |
409 | ||
410 | if (!t->rx_buf) { | |
411 | /* using the temporal preallocated and premapped buffer */ | |
412 | dma_sync_single_for_cpu(hw->dev, dma_rx_addr, t->len, | |
413 | DMA_FROM_DEVICE); | |
414 | } | |
415 | /* unmap buffers if mapped above */ | |
416 | if (t->rx_buf && t->rx_dma == 0 ) | |
417 | dma_unmap_single(hw->dev, dma_rx_addr, t->len, | |
418 | DMA_FROM_DEVICE); | |
419 | if (t->tx_buf && t->tx_dma == 0 ) | |
420 | dma_unmap_single(hw->dev, dma_tx_addr, t->len, | |
421 | DMA_TO_DEVICE); | |
422 | ||
423 | return hw->rx_count < hw->tx_count ? hw->rx_count : hw->tx_count; | |
424 | } | |
425 | ||
426 | static irqreturn_t au1550_spi_dma_irq_callback(struct au1550_spi *hw) | |
427 | { | |
428 | u32 stat, evnt; | |
429 | ||
430 | stat = hw->regs->psc_spistat; | |
431 | evnt = hw->regs->psc_spievent; | |
432 | au_sync(); | |
433 | if ((stat & PSC_SPISTAT_DI) == 0) { | |
434 | dev_err(hw->dev, "Unexpected IRQ!\n"); | |
435 | return IRQ_NONE; | |
436 | } | |
437 | ||
438 | if ((evnt & (PSC_SPIEVNT_MM | PSC_SPIEVNT_RO | |
439 | | PSC_SPIEVNT_RU | PSC_SPIEVNT_TO | |
440 | | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD)) | |
441 | != 0) { | |
442 | /* | |
443 | * due to an spi error we consider transfer as done, | |
444 | * so mask all events until before next transfer start | |
445 | * and stop the possibly running dma immediately | |
446 | */ | |
447 | au1550_spi_mask_ack_all(hw); | |
448 | au1xxx_dbdma_stop(hw->dma_rx_ch); | |
449 | au1xxx_dbdma_stop(hw->dma_tx_ch); | |
450 | ||
451 | /* get number of transferred bytes */ | |
452 | hw->rx_count = hw->len - au1xxx_get_dma_residue(hw->dma_rx_ch); | |
453 | hw->tx_count = hw->len - au1xxx_get_dma_residue(hw->dma_tx_ch); | |
454 | ||
455 | au1xxx_dbdma_reset(hw->dma_rx_ch); | |
456 | au1xxx_dbdma_reset(hw->dma_tx_ch); | |
457 | au1550_spi_reset_fifos(hw); | |
458 | ||
459 | if (evnt == PSC_SPIEVNT_RO) | |
460 | dev_err(hw->dev, | |
461 | "dma transfer: receive FIFO overflow!\n"); | |
462 | else | |
463 | dev_err(hw->dev, | |
464 | "dma transfer: unexpected SPI error " | |
465 | "(event=0x%x stat=0x%x)!\n", evnt, stat); | |
466 | ||
467 | complete(&hw->master_done); | |
468 | return IRQ_HANDLED; | |
469 | } | |
470 | ||
471 | if ((evnt & PSC_SPIEVNT_MD) != 0) { | |
472 | /* transfer completed successfully */ | |
473 | au1550_spi_mask_ack_all(hw); | |
474 | hw->rx_count = hw->len; | |
475 | hw->tx_count = hw->len; | |
476 | complete(&hw->master_done); | |
477 | } | |
478 | return IRQ_HANDLED; | |
479 | } | |
480 | ||
481 | ||
482 | /* routines to handle different word sizes in pio mode */ | |
483 | #define AU1550_SPI_RX_WORD(size, mask) \ | |
484 | static void au1550_spi_rx_word_##size(struct au1550_spi *hw) \ | |
485 | { \ | |
486 | u32 fifoword = hw->regs->psc_spitxrx & (u32)(mask); \ | |
487 | au_sync(); \ | |
488 | if (hw->rx) { \ | |
489 | *(u##size *)hw->rx = (u##size)fifoword; \ | |
490 | hw->rx += (size) / 8; \ | |
491 | } \ | |
492 | hw->rx_count += (size) / 8; \ | |
493 | } | |
494 | ||
495 | #define AU1550_SPI_TX_WORD(size, mask) \ | |
496 | static void au1550_spi_tx_word_##size(struct au1550_spi *hw) \ | |
497 | { \ | |
498 | u32 fifoword = 0; \ | |
499 | if (hw->tx) { \ | |
500 | fifoword = *(u##size *)hw->tx & (u32)(mask); \ | |
501 | hw->tx += (size) / 8; \ | |
502 | } \ | |
503 | hw->tx_count += (size) / 8; \ | |
504 | if (hw->tx_count >= hw->len) \ | |
505 | fifoword |= PSC_SPITXRX_LC; \ | |
506 | hw->regs->psc_spitxrx = fifoword; \ | |
507 | au_sync(); \ | |
508 | } | |
509 | ||
510 | AU1550_SPI_RX_WORD(8,0xff) | |
511 | AU1550_SPI_RX_WORD(16,0xffff) | |
512 | AU1550_SPI_RX_WORD(32,0xffffff) | |
513 | AU1550_SPI_TX_WORD(8,0xff) | |
514 | AU1550_SPI_TX_WORD(16,0xffff) | |
515 | AU1550_SPI_TX_WORD(32,0xffffff) | |
516 | ||
517 | static int au1550_spi_pio_txrxb(struct spi_device *spi, struct spi_transfer *t) | |
518 | { | |
519 | u32 stat, mask; | |
520 | struct au1550_spi *hw = spi_master_get_devdata(spi->master); | |
521 | ||
522 | hw->tx = t->tx_buf; | |
523 | hw->rx = t->rx_buf; | |
524 | hw->len = t->len; | |
525 | hw->tx_count = 0; | |
526 | hw->rx_count = 0; | |
527 | ||
528 | /* by default enable nearly all events after filling tx fifo */ | |
529 | mask = PSC_SPIMSK_SD; | |
530 | ||
531 | /* fill the transmit FIFO */ | |
532 | while (hw->tx_count < hw->len) { | |
533 | ||
534 | hw->tx_word(hw); | |
535 | ||
536 | if (hw->tx_count >= hw->len) { | |
537 | /* mask tx fifo request interrupt as we are done */ | |
538 | mask |= PSC_SPIMSK_TR; | |
539 | } | |
540 | ||
541 | stat = hw->regs->psc_spistat; | |
542 | au_sync(); | |
543 | if (stat & PSC_SPISTAT_TF) | |
544 | break; | |
545 | } | |
546 | ||
547 | /* enable event interrupts */ | |
548 | hw->regs->psc_spimsk = mask; | |
549 | au_sync(); | |
550 | ||
551 | /* start the transfer */ | |
552 | hw->regs->psc_spipcr = PSC_SPIPCR_MS; | |
553 | au_sync(); | |
554 | ||
555 | wait_for_completion(&hw->master_done); | |
556 | ||
557 | return hw->rx_count < hw->tx_count ? hw->rx_count : hw->tx_count; | |
558 | } | |
559 | ||
560 | static irqreturn_t au1550_spi_pio_irq_callback(struct au1550_spi *hw) | |
561 | { | |
562 | int busy; | |
563 | u32 stat, evnt; | |
564 | ||
565 | stat = hw->regs->psc_spistat; | |
566 | evnt = hw->regs->psc_spievent; | |
567 | au_sync(); | |
568 | if ((stat & PSC_SPISTAT_DI) == 0) { | |
569 | dev_err(hw->dev, "Unexpected IRQ!\n"); | |
570 | return IRQ_NONE; | |
571 | } | |
572 | ||
573 | if ((evnt & (PSC_SPIEVNT_MM | PSC_SPIEVNT_RO | |
574 | | PSC_SPIEVNT_RU | PSC_SPIEVNT_TO | |
575 | | PSC_SPIEVNT_SD)) | |
576 | != 0) { | |
577 | /* | |
578 | * due to an error we consider transfer as done, | |
579 | * so mask all events until before next transfer start | |
580 | */ | |
581 | au1550_spi_mask_ack_all(hw); | |
582 | au1550_spi_reset_fifos(hw); | |
583 | dev_err(hw->dev, | |
584 | "pio transfer: unexpected SPI error " | |
585 | "(event=0x%x stat=0x%x)!\n", evnt, stat); | |
586 | complete(&hw->master_done); | |
587 | return IRQ_HANDLED; | |
588 | } | |
589 | ||
590 | /* | |
591 | * while there is something to read from rx fifo | |
592 | * or there is a space to write to tx fifo: | |
593 | */ | |
594 | do { | |
595 | busy = 0; | |
596 | stat = hw->regs->psc_spistat; | |
597 | au_sync(); | |
598 | ||
599 | /* | |
600 | * Take care to not let the Rx FIFO overflow. | |
601 | * | |
602 | * We only write a byte if we have read one at least. Initially, | |
603 | * the write fifo is full, so we should read from the read fifo | |
604 | * first. | |
605 | * In case we miss a word from the read fifo, we should get a | |
606 | * RO event and should back out. | |
607 | */ | |
608 | if (!(stat & PSC_SPISTAT_RE) && hw->rx_count < hw->len) { | |
609 | hw->rx_word(hw); | |
610 | busy = 1; | |
611 | ||
612 | if (!(stat & PSC_SPISTAT_TF) && hw->tx_count < hw->len) | |
613 | hw->tx_word(hw); | |
614 | } | |
615 | } while (busy); | |
616 | ||
617 | hw->regs->psc_spievent = PSC_SPIEVNT_RR | PSC_SPIEVNT_TR; | |
618 | au_sync(); | |
619 | ||
620 | /* | |
621 | * Restart the SPI transmission in case of a transmit underflow. | |
622 | * This seems to work despite the notes in the Au1550 data book | |
623 | * of Figure 8-4 with flowchart for SPI master operation: | |
624 | * | |
625 | * """Note 1: An XFR Error Interrupt occurs, unless masked, | |
626 | * for any of the following events: Tx FIFO Underflow, | |
627 | * Rx FIFO Overflow, or Multiple-master Error | |
628 | * Note 2: In case of a Tx Underflow Error, all zeroes are | |
629 | * transmitted.""" | |
630 | * | |
631 | * By simply restarting the spi transfer on Tx Underflow Error, | |
632 | * we assume that spi transfer was paused instead of zeroes | |
633 | * transmittion mentioned in the Note 2 of Au1550 data book. | |
634 | */ | |
635 | if (evnt & PSC_SPIEVNT_TU) { | |
636 | hw->regs->psc_spievent = PSC_SPIEVNT_TU | PSC_SPIEVNT_MD; | |
637 | au_sync(); | |
638 | hw->regs->psc_spipcr = PSC_SPIPCR_MS; | |
639 | au_sync(); | |
640 | } | |
641 | ||
642 | if (hw->rx_count >= hw->len) { | |
643 | /* transfer completed successfully */ | |
644 | au1550_spi_mask_ack_all(hw); | |
645 | complete(&hw->master_done); | |
646 | } | |
647 | return IRQ_HANDLED; | |
648 | } | |
649 | ||
650 | static int au1550_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) | |
651 | { | |
652 | struct au1550_spi *hw = spi_master_get_devdata(spi->master); | |
653 | return hw->txrx_bufs(spi, t); | |
654 | } | |
655 | ||
656 | static irqreturn_t au1550_spi_irq(int irq, void *dev) | |
657 | { | |
658 | struct au1550_spi *hw = dev; | |
659 | return hw->irq_callback(hw); | |
660 | } | |
661 | ||
662 | static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw) | |
663 | { | |
664 | if (bpw <= 8) { | |
665 | if (hw->usedma) { | |
666 | hw->txrx_bufs = &au1550_spi_dma_txrxb; | |
667 | hw->irq_callback = &au1550_spi_dma_irq_callback; | |
668 | } else { | |
669 | hw->rx_word = &au1550_spi_rx_word_8; | |
670 | hw->tx_word = &au1550_spi_tx_word_8; | |
671 | hw->txrx_bufs = &au1550_spi_pio_txrxb; | |
672 | hw->irq_callback = &au1550_spi_pio_irq_callback; | |
673 | } | |
674 | } else if (bpw <= 16) { | |
675 | hw->rx_word = &au1550_spi_rx_word_16; | |
676 | hw->tx_word = &au1550_spi_tx_word_16; | |
677 | hw->txrx_bufs = &au1550_spi_pio_txrxb; | |
678 | hw->irq_callback = &au1550_spi_pio_irq_callback; | |
679 | } else { | |
680 | hw->rx_word = &au1550_spi_rx_word_32; | |
681 | hw->tx_word = &au1550_spi_tx_word_32; | |
682 | hw->txrx_bufs = &au1550_spi_pio_txrxb; | |
683 | hw->irq_callback = &au1550_spi_pio_irq_callback; | |
684 | } | |
685 | } | |
686 | ||
687 | static void au1550_spi_setup_psc_as_spi(struct au1550_spi *hw) | |
688 | { | |
689 | u32 stat, cfg; | |
690 | ||
691 | /* set up the PSC for SPI mode */ | |
692 | hw->regs->psc_ctrl = PSC_CTRL_DISABLE; | |
693 | au_sync(); | |
694 | hw->regs->psc_sel = PSC_SEL_PS_SPIMODE; | |
695 | au_sync(); | |
696 | ||
697 | hw->regs->psc_spicfg = 0; | |
698 | au_sync(); | |
699 | ||
700 | hw->regs->psc_ctrl = PSC_CTRL_ENABLE; | |
701 | au_sync(); | |
702 | ||
703 | do { | |
704 | stat = hw->regs->psc_spistat; | |
705 | au_sync(); | |
706 | } while ((stat & PSC_SPISTAT_SR) == 0); | |
707 | ||
708 | ||
709 | cfg = hw->usedma ? 0 : PSC_SPICFG_DD_DISABLE; | |
710 | cfg |= PSC_SPICFG_SET_LEN(8); | |
711 | cfg |= PSC_SPICFG_RT_FIFO8 | PSC_SPICFG_TT_FIFO8; | |
712 | /* use minimal allowed brg and div values as initial setting: */ | |
713 | cfg |= PSC_SPICFG_SET_BAUD(4) | PSC_SPICFG_SET_DIV(0); | |
714 | ||
715 | #ifdef AU1550_SPI_DEBUG_LOOPBACK | |
716 | cfg |= PSC_SPICFG_LB; | |
717 | #endif | |
718 | ||
719 | hw->regs->psc_spicfg = cfg; | |
720 | au_sync(); | |
721 | ||
722 | au1550_spi_mask_ack_all(hw); | |
723 | ||
724 | hw->regs->psc_spicfg |= PSC_SPICFG_DE_ENABLE; | |
725 | au_sync(); | |
726 | ||
727 | do { | |
728 | stat = hw->regs->psc_spistat; | |
729 | au_sync(); | |
730 | } while ((stat & PSC_SPISTAT_DR) == 0); | |
731 | ||
732 | au1550_spi_reset_fifos(hw); | |
733 | } | |
734 | ||
735 | ||
736 | static int au1550_spi_probe(struct platform_device *pdev) | |
737 | { | |
738 | struct au1550_spi *hw; | |
739 | struct spi_master *master; | |
740 | struct resource *r; | |
741 | int err = 0; | |
742 | ||
743 | master = spi_alloc_master(&pdev->dev, sizeof(struct au1550_spi)); | |
744 | if (master == NULL) { | |
745 | dev_err(&pdev->dev, "No memory for spi_master\n"); | |
746 | err = -ENOMEM; | |
747 | goto err_nomem; | |
748 | } | |
749 | ||
750 | /* the spi->mode bits understood by this driver: */ | |
751 | master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST; | |
752 | master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 24); | |
753 | ||
754 | hw = spi_master_get_devdata(master); | |
755 | ||
756 | hw->master = master; | |
757 | hw->pdata = dev_get_platdata(&pdev->dev); | |
758 | hw->dev = &pdev->dev; | |
759 | ||
760 | if (hw->pdata == NULL) { | |
761 | dev_err(&pdev->dev, "No platform data supplied\n"); | |
762 | err = -ENOENT; | |
763 | goto err_no_pdata; | |
764 | } | |
765 | ||
766 | r = platform_get_resource(pdev, IORESOURCE_IRQ, 0); | |
767 | if (!r) { | |
768 | dev_err(&pdev->dev, "no IRQ\n"); | |
769 | err = -ENODEV; | |
770 | goto err_no_iores; | |
771 | } | |
772 | hw->irq = r->start; | |
773 | ||
774 | hw->usedma = 0; | |
775 | r = platform_get_resource(pdev, IORESOURCE_DMA, 0); | |
776 | if (r) { | |
777 | hw->dma_tx_id = r->start; | |
778 | r = platform_get_resource(pdev, IORESOURCE_DMA, 1); | |
779 | if (r) { | |
780 | hw->dma_rx_id = r->start; | |
781 | if (usedma && ddma_memid) { | |
782 | if (pdev->dev.dma_mask == NULL) | |
783 | dev_warn(&pdev->dev, "no dma mask\n"); | |
784 | else | |
785 | hw->usedma = 1; | |
786 | } | |
787 | } | |
788 | } | |
789 | ||
790 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
791 | if (!r) { | |
792 | dev_err(&pdev->dev, "no mmio resource\n"); | |
793 | err = -ENODEV; | |
794 | goto err_no_iores; | |
795 | } | |
796 | ||
797 | hw->ioarea = request_mem_region(r->start, sizeof(psc_spi_t), | |
798 | pdev->name); | |
799 | if (!hw->ioarea) { | |
800 | dev_err(&pdev->dev, "Cannot reserve iomem region\n"); | |
801 | err = -ENXIO; | |
802 | goto err_no_iores; | |
803 | } | |
804 | ||
805 | hw->regs = (psc_spi_t __iomem *)ioremap(r->start, sizeof(psc_spi_t)); | |
806 | if (!hw->regs) { | |
807 | dev_err(&pdev->dev, "cannot ioremap\n"); | |
808 | err = -ENXIO; | |
809 | goto err_ioremap; | |
810 | } | |
811 | ||
812 | platform_set_drvdata(pdev, hw); | |
813 | ||
814 | init_completion(&hw->master_done); | |
815 | ||
816 | hw->bitbang.master = hw->master; | |
817 | hw->bitbang.setup_transfer = au1550_spi_setupxfer; | |
818 | hw->bitbang.chipselect = au1550_spi_chipsel; | |
819 | hw->bitbang.txrx_bufs = au1550_spi_txrx_bufs; | |
820 | ||
821 | if (hw->usedma) { | |
822 | hw->dma_tx_ch = au1xxx_dbdma_chan_alloc(ddma_memid, | |
823 | hw->dma_tx_id, NULL, (void *)hw); | |
824 | if (hw->dma_tx_ch == 0) { | |
825 | dev_err(&pdev->dev, | |
826 | "Cannot allocate tx dma channel\n"); | |
827 | err = -ENXIO; | |
828 | goto err_no_txdma; | |
829 | } | |
830 | au1xxx_dbdma_set_devwidth(hw->dma_tx_ch, 8); | |
831 | if (au1xxx_dbdma_ring_alloc(hw->dma_tx_ch, | |
832 | AU1550_SPI_DBDMA_DESCRIPTORS) == 0) { | |
833 | dev_err(&pdev->dev, | |
834 | "Cannot allocate tx dma descriptors\n"); | |
835 | err = -ENXIO; | |
836 | goto err_no_txdma_descr; | |
837 | } | |
838 | ||
839 | ||
840 | hw->dma_rx_ch = au1xxx_dbdma_chan_alloc(hw->dma_rx_id, | |
841 | ddma_memid, NULL, (void *)hw); | |
842 | if (hw->dma_rx_ch == 0) { | |
843 | dev_err(&pdev->dev, | |
844 | "Cannot allocate rx dma channel\n"); | |
845 | err = -ENXIO; | |
846 | goto err_no_rxdma; | |
847 | } | |
848 | au1xxx_dbdma_set_devwidth(hw->dma_rx_ch, 8); | |
849 | if (au1xxx_dbdma_ring_alloc(hw->dma_rx_ch, | |
850 | AU1550_SPI_DBDMA_DESCRIPTORS) == 0) { | |
851 | dev_err(&pdev->dev, | |
852 | "Cannot allocate rx dma descriptors\n"); | |
853 | err = -ENXIO; | |
854 | goto err_no_rxdma_descr; | |
855 | } | |
856 | ||
857 | err = au1550_spi_dma_rxtmp_alloc(hw, | |
858 | AU1550_SPI_DMA_RXTMP_MINSIZE); | |
859 | if (err < 0) { | |
860 | dev_err(&pdev->dev, | |
861 | "Cannot allocate initial rx dma tmp buffer\n"); | |
862 | goto err_dma_rxtmp_alloc; | |
863 | } | |
864 | } | |
865 | ||
866 | au1550_spi_bits_handlers_set(hw, 8); | |
867 | ||
868 | err = request_irq(hw->irq, au1550_spi_irq, 0, pdev->name, hw); | |
869 | if (err) { | |
870 | dev_err(&pdev->dev, "Cannot claim IRQ\n"); | |
871 | goto err_no_irq; | |
872 | } | |
873 | ||
874 | master->bus_num = pdev->id; | |
875 | master->num_chipselect = hw->pdata->num_chipselect; | |
876 | ||
877 | /* | |
878 | * precompute valid range for spi freq - from au1550 datasheet: | |
879 | * psc_tempclk = psc_mainclk / (2 << DIV) | |
880 | * spiclk = psc_tempclk / (2 * (BRG + 1)) | |
881 | * BRG valid range is 4..63 | |
882 | * DIV valid range is 0..3 | |
883 | * round the min and max frequencies to values that would still | |
884 | * produce valid brg and div | |
885 | */ | |
886 | { | |
887 | int min_div = (2 << 0) * (2 * (4 + 1)); | |
888 | int max_div = (2 << 3) * (2 * (63 + 1)); | |
889 | master->max_speed_hz = hw->pdata->mainclk_hz / min_div; | |
890 | master->min_speed_hz = | |
891 | hw->pdata->mainclk_hz / (max_div + 1) + 1; | |
892 | } | |
893 | ||
894 | au1550_spi_setup_psc_as_spi(hw); | |
895 | ||
896 | err = spi_bitbang_start(&hw->bitbang); | |
897 | if (err) { | |
898 | dev_err(&pdev->dev, "Failed to register SPI master\n"); | |
899 | goto err_register; | |
900 | } | |
901 | ||
902 | dev_info(&pdev->dev, | |
903 | "spi master registered: bus_num=%d num_chipselect=%d\n", | |
904 | master->bus_num, master->num_chipselect); | |
905 | ||
906 | return 0; | |
907 | ||
908 | err_register: | |
909 | free_irq(hw->irq, hw); | |
910 | ||
911 | err_no_irq: | |
912 | au1550_spi_dma_rxtmp_free(hw); | |
913 | ||
914 | err_dma_rxtmp_alloc: | |
915 | err_no_rxdma_descr: | |
916 | if (hw->usedma) | |
917 | au1xxx_dbdma_chan_free(hw->dma_rx_ch); | |
918 | ||
919 | err_no_rxdma: | |
920 | err_no_txdma_descr: | |
921 | if (hw->usedma) | |
922 | au1xxx_dbdma_chan_free(hw->dma_tx_ch); | |
923 | ||
924 | err_no_txdma: | |
925 | iounmap((void __iomem *)hw->regs); | |
926 | ||
927 | err_ioremap: | |
928 | release_resource(hw->ioarea); | |
929 | kfree(hw->ioarea); | |
930 | ||
931 | err_no_iores: | |
932 | err_no_pdata: | |
933 | spi_master_put(hw->master); | |
934 | ||
935 | err_nomem: | |
936 | return err; | |
937 | } | |
938 | ||
939 | static int au1550_spi_remove(struct platform_device *pdev) | |
940 | { | |
941 | struct au1550_spi *hw = platform_get_drvdata(pdev); | |
942 | ||
943 | dev_info(&pdev->dev, "spi master remove: bus_num=%d\n", | |
944 | hw->master->bus_num); | |
945 | ||
946 | spi_bitbang_stop(&hw->bitbang); | |
947 | free_irq(hw->irq, hw); | |
948 | iounmap((void __iomem *)hw->regs); | |
949 | release_resource(hw->ioarea); | |
950 | kfree(hw->ioarea); | |
951 | ||
952 | if (hw->usedma) { | |
953 | au1550_spi_dma_rxtmp_free(hw); | |
954 | au1xxx_dbdma_chan_free(hw->dma_rx_ch); | |
955 | au1xxx_dbdma_chan_free(hw->dma_tx_ch); | |
956 | } | |
957 | ||
958 | spi_master_put(hw->master); | |
959 | return 0; | |
960 | } | |
961 | ||
962 | /* work with hotplug and coldplug */ | |
963 | MODULE_ALIAS("platform:au1550-spi"); | |
964 | ||
965 | static struct platform_driver au1550_spi_drv = { | |
966 | .probe = au1550_spi_probe, | |
967 | .remove = au1550_spi_remove, | |
968 | .driver = { | |
969 | .name = "au1550-spi", | |
970 | .owner = THIS_MODULE, | |
971 | }, | |
972 | }; | |
973 | ||
974 | static int __init au1550_spi_init(void) | |
975 | { | |
976 | /* | |
977 | * create memory device with 8 bits dev_devwidth | |
978 | * needed for proper byte ordering to spi fifo | |
979 | */ | |
980 | switch (alchemy_get_cputype()) { | |
981 | case ALCHEMY_CPU_AU1550: | |
982 | case ALCHEMY_CPU_AU1200: | |
983 | case ALCHEMY_CPU_AU1300: | |
984 | break; | |
985 | default: | |
986 | return -ENODEV; | |
987 | } | |
988 | ||
989 | if (usedma) { | |
990 | ddma_memid = au1xxx_ddma_add_device(&au1550_spi_mem_dbdev); | |
991 | if (!ddma_memid) | |
992 | printk(KERN_ERR "au1550-spi: cannot add memory" | |
993 | "dbdma device\n"); | |
994 | } | |
995 | return platform_driver_register(&au1550_spi_drv); | |
996 | } | |
997 | module_init(au1550_spi_init); | |
998 | ||
999 | static void __exit au1550_spi_exit(void) | |
1000 | { | |
1001 | if (usedma && ddma_memid) | |
1002 | au1xxx_ddma_del_device(ddma_memid); | |
1003 | platform_driver_unregister(&au1550_spi_drv); | |
1004 | } | |
1005 | module_exit(au1550_spi_exit); | |
1006 | ||
1007 | MODULE_DESCRIPTION("Au1550 PSC SPI Driver"); | |
1008 | MODULE_AUTHOR("Jan Nikitenko <jan.nikitenko@gmail.com>"); | |
1009 | MODULE_LICENSE("GPL"); |