1 /*
2 * Freescale SPI controller driver cpm functions.
3 *
4 * Maintainer: Kumar Gala
5 *
6 * Copyright (C) 2006 Polycom, Inc.
7 * Copyright 2010 Freescale Semiconductor, Inc.
8 *
9 * CPM SPI and QE buffer descriptors mode support:
10 * Copyright (c) 2009 MontaVista Software, Inc.
11 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
12 *
13 * This program is free software; you can redistribute it and/or modify it
14 * under the terms of the GNU General Public License as published by the
15 * Free Software Foundation; either version 2 of the License, or (at your
16 * option) any later version.
17 */
18 #include <asm/cpm.h>
19 #include <soc/fsl/qe/qe.h>
20 #include <linux/dma-mapping.h>
21 #include <linux/fsl_devices.h>
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/of_address.h>
25 #include <linux/spi/spi.h>
26 #include <linux/types.h>
27 #include <linux/platform_device.h>
28
29 #include "spi-fsl-cpm.h"
30 #include "spi-fsl-lib.h"
31 #include "spi-fsl-spi.h"
32
33 /* CPM1 and CPM2 are mutually exclusive. */
34 #ifdef CONFIG_CPM1
35 #include <asm/cpm1.h>
36 #define CPM_SPI_CMD mk_cr_cmd(CPM_CR_CH_SPI, 0)
37 #else
38 #include <asm/cpm2.h>
39 #define CPM_SPI_CMD mk_cr_cmd(CPM_CR_SPI_PAGE, CPM_CR_SPI_SBLOCK, 0, 0)
40 #endif
41
42 #define SPIE_TXB 0x00000200 /* Last char is written to tx fifo */
43 #define SPIE_RXB 0x00000100 /* Last char is written to rx buf */
44
45 /* SPCOM register values */
46 #define SPCOM_STR (1 << 23) /* Start transmit */
47
48 #define SPI_PRAM_SIZE 0x100
49 #define SPI_MRBLR ((unsigned int)PAGE_SIZE)
50
51 static void *fsl_dummy_rx;
52 static DEFINE_MUTEX(fsl_dummy_rx_lock);
53 static int fsl_dummy_rx_refcnt;
54
fsl_spi_cpm_reinit_txrx(struct mpc8xxx_spi * mspi)55 void fsl_spi_cpm_reinit_txrx(struct mpc8xxx_spi *mspi)
56 {
57 if (mspi->flags & SPI_QE) {
58 qe_issue_cmd(QE_INIT_TX_RX, mspi->subblock,
59 QE_CR_PROTOCOL_UNSPECIFIED, 0);
60 } else {
61 if (mspi->flags & SPI_CPM1) {
62 out_be32(&mspi->pram->rstate, 0);
63 out_be16(&mspi->pram->rbptr,
64 in_be16(&mspi->pram->rbase));
65 out_be32(&mspi->pram->tstate, 0);
66 out_be16(&mspi->pram->tbptr,
67 in_be16(&mspi->pram->tbase));
68 } else {
69 cpm_command(CPM_SPI_CMD, CPM_CR_INIT_TRX);
70 }
71 }
72 }
73 EXPORT_SYMBOL_GPL(fsl_spi_cpm_reinit_txrx);
74
fsl_spi_cpm_bufs_start(struct mpc8xxx_spi * mspi)75 static void fsl_spi_cpm_bufs_start(struct mpc8xxx_spi *mspi)
76 {
77 struct cpm_buf_desc __iomem *tx_bd = mspi->tx_bd;
78 struct cpm_buf_desc __iomem *rx_bd = mspi->rx_bd;
79 unsigned int xfer_len = min(mspi->count, SPI_MRBLR);
80 unsigned int xfer_ofs;
81 struct fsl_spi_reg *reg_base = mspi->reg_base;
82
83 xfer_ofs = mspi->xfer_in_progress->len - mspi->count;
84
85 if (mspi->rx_dma == mspi->dma_dummy_rx)
86 out_be32(&rx_bd->cbd_bufaddr, mspi->rx_dma);
87 else
88 out_be32(&rx_bd->cbd_bufaddr, mspi->rx_dma + xfer_ofs);
89 out_be16(&rx_bd->cbd_datlen, 0);
90 out_be16(&rx_bd->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT | BD_SC_WRAP);
91
92 if (mspi->tx_dma == mspi->dma_dummy_tx)
93 out_be32(&tx_bd->cbd_bufaddr, mspi->tx_dma);
94 else
95 out_be32(&tx_bd->cbd_bufaddr, mspi->tx_dma + xfer_ofs);
96 out_be16(&tx_bd->cbd_datlen, xfer_len);
97 out_be16(&tx_bd->cbd_sc, BD_SC_READY | BD_SC_INTRPT | BD_SC_WRAP |
98 BD_SC_LAST);
99
100 /* start transfer */
101 mpc8xxx_spi_write_reg(®_base->command, SPCOM_STR);
102 }
103
fsl_spi_cpm_bufs(struct mpc8xxx_spi * mspi,struct spi_transfer * t,bool is_dma_mapped)104 int fsl_spi_cpm_bufs(struct mpc8xxx_spi *mspi,
105 struct spi_transfer *t, bool is_dma_mapped)
106 {
107 struct device *dev = mspi->dev;
108 struct fsl_spi_reg *reg_base = mspi->reg_base;
109
110 if (is_dma_mapped) {
111 mspi->map_tx_dma = 0;
112 mspi->map_rx_dma = 0;
113 } else {
114 mspi->map_tx_dma = 1;
115 mspi->map_rx_dma = 1;
116 }
117
118 if (!t->tx_buf) {
119 mspi->tx_dma = mspi->dma_dummy_tx;
120 mspi->map_tx_dma = 0;
121 }
122
123 if (!t->rx_buf) {
124 mspi->rx_dma = mspi->dma_dummy_rx;
125 mspi->map_rx_dma = 0;
126 }
127
128 if (mspi->map_tx_dma) {
129 void *nonconst_tx = (void *)mspi->tx; /* shut up gcc */
130
131 mspi->tx_dma = dma_map_single(dev, nonconst_tx, t->len,
132 DMA_TO_DEVICE);
133 if (dma_mapping_error(dev, mspi->tx_dma)) {
134 dev_err(dev, "unable to map tx dma\n");
135 return -ENOMEM;
136 }
137 } else if (t->tx_buf) {
138 mspi->tx_dma = t->tx_dma;
139 }
140
141 if (mspi->map_rx_dma) {
142 mspi->rx_dma = dma_map_single(dev, mspi->rx, t->len,
143 DMA_FROM_DEVICE);
144 if (dma_mapping_error(dev, mspi->rx_dma)) {
145 dev_err(dev, "unable to map rx dma\n");
146 goto err_rx_dma;
147 }
148 } else if (t->rx_buf) {
149 mspi->rx_dma = t->rx_dma;
150 }
151
152 /* enable rx ints */
153 mpc8xxx_spi_write_reg(®_base->mask, SPIE_RXB);
154
155 mspi->xfer_in_progress = t;
156 mspi->count = t->len;
157
158 /* start CPM transfers */
159 fsl_spi_cpm_bufs_start(mspi);
160
161 return 0;
162
163 err_rx_dma:
164 if (mspi->map_tx_dma)
165 dma_unmap_single(dev, mspi->tx_dma, t->len, DMA_TO_DEVICE);
166 return -ENOMEM;
167 }
168 EXPORT_SYMBOL_GPL(fsl_spi_cpm_bufs);
169
fsl_spi_cpm_bufs_complete(struct mpc8xxx_spi * mspi)170 void fsl_spi_cpm_bufs_complete(struct mpc8xxx_spi *mspi)
171 {
172 struct device *dev = mspi->dev;
173 struct spi_transfer *t = mspi->xfer_in_progress;
174
175 if (mspi->map_tx_dma)
176 dma_unmap_single(dev, mspi->tx_dma, t->len, DMA_TO_DEVICE);
177 if (mspi->map_rx_dma)
178 dma_unmap_single(dev, mspi->rx_dma, t->len, DMA_FROM_DEVICE);
179 mspi->xfer_in_progress = NULL;
180 }
181 EXPORT_SYMBOL_GPL(fsl_spi_cpm_bufs_complete);
182
fsl_spi_cpm_irq(struct mpc8xxx_spi * mspi,u32 events)183 void fsl_spi_cpm_irq(struct mpc8xxx_spi *mspi, u32 events)
184 {
185 u16 len;
186 struct fsl_spi_reg *reg_base = mspi->reg_base;
187
188 dev_dbg(mspi->dev, "%s: bd datlen %d, count %d\n", __func__,
189 in_be16(&mspi->rx_bd->cbd_datlen), mspi->count);
190
191 len = in_be16(&mspi->rx_bd->cbd_datlen);
192 if (len > mspi->count) {
193 WARN_ON(1);
194 len = mspi->count;
195 }
196
197 /* Clear the events */
198 mpc8xxx_spi_write_reg(®_base->event, events);
199
200 mspi->count -= len;
201 if (mspi->count)
202 fsl_spi_cpm_bufs_start(mspi);
203 else
204 complete(&mspi->done);
205 }
206 EXPORT_SYMBOL_GPL(fsl_spi_cpm_irq);
207
fsl_spi_alloc_dummy_rx(void)208 static void *fsl_spi_alloc_dummy_rx(void)
209 {
210 mutex_lock(&fsl_dummy_rx_lock);
211
212 if (!fsl_dummy_rx)
213 fsl_dummy_rx = kmalloc(SPI_MRBLR, GFP_KERNEL);
214 if (fsl_dummy_rx)
215 fsl_dummy_rx_refcnt++;
216
217 mutex_unlock(&fsl_dummy_rx_lock);
218
219 return fsl_dummy_rx;
220 }
221
fsl_spi_free_dummy_rx(void)222 static void fsl_spi_free_dummy_rx(void)
223 {
224 mutex_lock(&fsl_dummy_rx_lock);
225
226 switch (fsl_dummy_rx_refcnt) {
227 case 0:
228 WARN_ON(1);
229 break;
230 case 1:
231 kfree(fsl_dummy_rx);
232 fsl_dummy_rx = NULL;
233 /* fall through */
234 default:
235 fsl_dummy_rx_refcnt--;
236 break;
237 }
238
239 mutex_unlock(&fsl_dummy_rx_lock);
240 }
241
fsl_spi_cpm_get_pram(struct mpc8xxx_spi * mspi)242 static unsigned long fsl_spi_cpm_get_pram(struct mpc8xxx_spi *mspi)
243 {
244 struct device *dev = mspi->dev;
245 struct device_node *np = dev->of_node;
246 const u32 *iprop;
247 int size;
248 void __iomem *spi_base;
249 unsigned long pram_ofs = -ENOMEM;
250
251 /* Can't use of_address_to_resource(), QE muram isn't at 0. */
252 iprop = of_get_property(np, "reg", &size);
253
254 /* QE with a fixed pram location? */
255 if (mspi->flags & SPI_QE && iprop && size == sizeof(*iprop) * 4)
256 return cpm_muram_alloc_fixed(iprop[2], SPI_PRAM_SIZE);
257
258 /* QE but with a dynamic pram location? */
259 if (mspi->flags & SPI_QE) {
260 pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
261 qe_issue_cmd(QE_ASSIGN_PAGE_TO_DEVICE, mspi->subblock,
262 QE_CR_PROTOCOL_UNSPECIFIED, pram_ofs);
263 return pram_ofs;
264 }
265
266 spi_base = of_iomap(np, 1);
267 if (spi_base == NULL)
268 return -EINVAL;
269
270 if (mspi->flags & SPI_CPM2) {
271 pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
272 out_be16(spi_base, pram_ofs);
273 }
274
275 iounmap(spi_base);
276 return pram_ofs;
277 }
278
fsl_spi_cpm_init(struct mpc8xxx_spi * mspi)279 int fsl_spi_cpm_init(struct mpc8xxx_spi *mspi)
280 {
281 struct device *dev = mspi->dev;
282 struct device_node *np = dev->of_node;
283 const u32 *iprop;
284 int size;
285 unsigned long bds_ofs;
286
287 if (!(mspi->flags & SPI_CPM_MODE))
288 return 0;
289
290 if (!fsl_spi_alloc_dummy_rx())
291 return -ENOMEM;
292
293 if (mspi->flags & SPI_QE) {
294 iprop = of_get_property(np, "cell-index", &size);
295 if (iprop && size == sizeof(*iprop))
296 mspi->subblock = *iprop;
297
298 switch (mspi->subblock) {
299 default:
300 dev_warn(dev, "cell-index unspecified, assuming SPI1\n");
301 /* fall through */
302 case 0:
303 mspi->subblock = QE_CR_SUBBLOCK_SPI1;
304 break;
305 case 1:
306 mspi->subblock = QE_CR_SUBBLOCK_SPI2;
307 break;
308 }
309 }
310
311 if (mspi->flags & SPI_CPM1) {
312 struct resource *res;
313 void *pram;
314
315 res = platform_get_resource(to_platform_device(dev),
316 IORESOURCE_MEM, 1);
317 pram = devm_ioremap_resource(dev, res);
318 if (IS_ERR(pram))
319 mspi->pram = NULL;
320 else
321 mspi->pram = pram;
322 } else {
323 unsigned long pram_ofs = fsl_spi_cpm_get_pram(mspi);
324
325 if (IS_ERR_VALUE(pram_ofs))
326 mspi->pram = NULL;
327 else
328 mspi->pram = cpm_muram_addr(pram_ofs);
329 }
330 if (mspi->pram == NULL) {
331 dev_err(dev, "can't allocate spi parameter ram\n");
332 goto err_pram;
333 }
334
335 bds_ofs = cpm_muram_alloc(sizeof(*mspi->tx_bd) +
336 sizeof(*mspi->rx_bd), 8);
337 if (IS_ERR_VALUE(bds_ofs)) {
338 dev_err(dev, "can't allocate bds\n");
339 goto err_bds;
340 }
341
342 mspi->dma_dummy_tx = dma_map_single(dev, empty_zero_page, PAGE_SIZE,
343 DMA_TO_DEVICE);
344 if (dma_mapping_error(dev, mspi->dma_dummy_tx)) {
345 dev_err(dev, "unable to map dummy tx buffer\n");
346 goto err_dummy_tx;
347 }
348
349 mspi->dma_dummy_rx = dma_map_single(dev, fsl_dummy_rx, SPI_MRBLR,
350 DMA_FROM_DEVICE);
351 if (dma_mapping_error(dev, mspi->dma_dummy_rx)) {
352 dev_err(dev, "unable to map dummy rx buffer\n");
353 goto err_dummy_rx;
354 }
355
356 mspi->tx_bd = cpm_muram_addr(bds_ofs);
357 mspi->rx_bd = cpm_muram_addr(bds_ofs + sizeof(*mspi->tx_bd));
358
359 /* Initialize parameter ram. */
360 out_be16(&mspi->pram->tbase, cpm_muram_offset(mspi->tx_bd));
361 out_be16(&mspi->pram->rbase, cpm_muram_offset(mspi->rx_bd));
362 out_8(&mspi->pram->tfcr, CPMFCR_EB | CPMFCR_GBL);
363 out_8(&mspi->pram->rfcr, CPMFCR_EB | CPMFCR_GBL);
364 out_be16(&mspi->pram->mrblr, SPI_MRBLR);
365 out_be32(&mspi->pram->rstate, 0);
366 out_be32(&mspi->pram->rdp, 0);
367 out_be16(&mspi->pram->rbptr, 0);
368 out_be16(&mspi->pram->rbc, 0);
369 out_be32(&mspi->pram->rxtmp, 0);
370 out_be32(&mspi->pram->tstate, 0);
371 out_be32(&mspi->pram->tdp, 0);
372 out_be16(&mspi->pram->tbptr, 0);
373 out_be16(&mspi->pram->tbc, 0);
374 out_be32(&mspi->pram->txtmp, 0);
375
376 return 0;
377
378 err_dummy_rx:
379 dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
380 err_dummy_tx:
381 cpm_muram_free(bds_ofs);
382 err_bds:
383 if (!(mspi->flags & SPI_CPM1))
384 cpm_muram_free(cpm_muram_offset(mspi->pram));
385 err_pram:
386 fsl_spi_free_dummy_rx();
387 return -ENOMEM;
388 }
389 EXPORT_SYMBOL_GPL(fsl_spi_cpm_init);
390
fsl_spi_cpm_free(struct mpc8xxx_spi * mspi)391 void fsl_spi_cpm_free(struct mpc8xxx_spi *mspi)
392 {
393 struct device *dev = mspi->dev;
394
395 if (!(mspi->flags & SPI_CPM_MODE))
396 return;
397
398 dma_unmap_single(dev, mspi->dma_dummy_rx, SPI_MRBLR, DMA_FROM_DEVICE);
399 dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
400 cpm_muram_free(cpm_muram_offset(mspi->tx_bd));
401 cpm_muram_free(cpm_muram_offset(mspi->pram));
402 fsl_spi_free_dummy_rx();
403 }
404 EXPORT_SYMBOL_GPL(fsl_spi_cpm_free);
405
406 MODULE_LICENSE("GPL");
407