1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Freescale SPI controller driver cpm functions.
4 *
5 * Maintainer: Kumar Gala
6 *
7 * Copyright (C) 2006 Polycom, Inc.
8 * Copyright 2010 Freescale Semiconductor, Inc.
9 *
10 * CPM SPI and QE buffer descriptors mode support:
11 * Copyright (c) 2009 MontaVista Software, Inc.
12 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
13 */
14 #include <asm/cpm.h>
15 #include <soc/fsl/qe/qe.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/fsl_devices.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/of_address.h>
21 #include <linux/spi/spi.h>
22 #include <linux/types.h>
23 #include <linux/platform_device.h>
24 #include <linux/byteorder/generic.h>
25
26 #include "spi-fsl-cpm.h"
27 #include "spi-fsl-lib.h"
28 #include "spi-fsl-spi.h"
29
30 /* CPM1 and CPM2 are mutually exclusive. */
31 #ifdef CONFIG_CPM1
32 #include <asm/cpm1.h>
33 #define CPM_SPI_CMD mk_cr_cmd(CPM_CR_CH_SPI, 0)
34 #else
35 #include <asm/cpm2.h>
36 #define CPM_SPI_CMD mk_cr_cmd(CPM_CR_SPI_PAGE, CPM_CR_SPI_SBLOCK, 0, 0)
37 #endif
38
39 #define SPIE_TXB 0x00000200 /* Last char is written to tx fifo */
40 #define SPIE_RXB 0x00000100 /* Last char is written to rx buf */
41
42 /* SPCOM register values */
43 #define SPCOM_STR (1 << 23) /* Start transmit */
44
45 #define SPI_PRAM_SIZE 0x100
46 #define SPI_MRBLR ((unsigned int)PAGE_SIZE)
47
48 static void *fsl_dummy_rx;
49 static DEFINE_MUTEX(fsl_dummy_rx_lock);
50 static int fsl_dummy_rx_refcnt;
51
fsl_spi_cpm_reinit_txrx(struct mpc8xxx_spi * mspi)52 void fsl_spi_cpm_reinit_txrx(struct mpc8xxx_spi *mspi)
53 {
54 if (mspi->flags & SPI_QE) {
55 qe_issue_cmd(QE_INIT_TX_RX, mspi->subblock,
56 QE_CR_PROTOCOL_UNSPECIFIED, 0);
57 } else {
58 if (mspi->flags & SPI_CPM1) {
59 out_be32(&mspi->pram->rstate, 0);
60 out_be16(&mspi->pram->rbptr,
61 in_be16(&mspi->pram->rbase));
62 out_be32(&mspi->pram->tstate, 0);
63 out_be16(&mspi->pram->tbptr,
64 in_be16(&mspi->pram->tbase));
65 } else {
66 cpm_command(CPM_SPI_CMD, CPM_CR_INIT_TRX);
67 }
68 }
69 }
70 EXPORT_SYMBOL_GPL(fsl_spi_cpm_reinit_txrx);
71
fsl_spi_cpm_bufs_start(struct mpc8xxx_spi * mspi)72 static void fsl_spi_cpm_bufs_start(struct mpc8xxx_spi *mspi)
73 {
74 struct cpm_buf_desc __iomem *tx_bd = mspi->tx_bd;
75 struct cpm_buf_desc __iomem *rx_bd = mspi->rx_bd;
76 unsigned int xfer_len = min(mspi->count, SPI_MRBLR);
77 unsigned int xfer_ofs;
78 struct fsl_spi_reg *reg_base = mspi->reg_base;
79
80 xfer_ofs = mspi->xfer_in_progress->len - mspi->count;
81
82 if (mspi->rx_dma == mspi->dma_dummy_rx)
83 out_be32(&rx_bd->cbd_bufaddr, mspi->rx_dma);
84 else
85 out_be32(&rx_bd->cbd_bufaddr, mspi->rx_dma + xfer_ofs);
86 out_be16(&rx_bd->cbd_datlen, 0);
87 out_be16(&rx_bd->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT | BD_SC_WRAP);
88
89 if (mspi->tx_dma == mspi->dma_dummy_tx)
90 out_be32(&tx_bd->cbd_bufaddr, mspi->tx_dma);
91 else
92 out_be32(&tx_bd->cbd_bufaddr, mspi->tx_dma + xfer_ofs);
93 out_be16(&tx_bd->cbd_datlen, xfer_len);
94 out_be16(&tx_bd->cbd_sc, BD_SC_READY | BD_SC_INTRPT | BD_SC_WRAP |
95 BD_SC_LAST);
96
97 /* start transfer */
98 mpc8xxx_spi_write_reg(®_base->command, SPCOM_STR);
99 }
100
fsl_spi_cpm_bufs(struct mpc8xxx_spi * mspi,struct spi_transfer * t,bool is_dma_mapped)101 int fsl_spi_cpm_bufs(struct mpc8xxx_spi *mspi,
102 struct spi_transfer *t, bool is_dma_mapped)
103 {
104 struct device *dev = mspi->dev;
105 struct fsl_spi_reg *reg_base = mspi->reg_base;
106
107 if (is_dma_mapped) {
108 mspi->map_tx_dma = 0;
109 mspi->map_rx_dma = 0;
110 } else {
111 mspi->map_tx_dma = 1;
112 mspi->map_rx_dma = 1;
113 }
114
115 if (!t->tx_buf) {
116 mspi->tx_dma = mspi->dma_dummy_tx;
117 mspi->map_tx_dma = 0;
118 }
119
120 if (!t->rx_buf) {
121 mspi->rx_dma = mspi->dma_dummy_rx;
122 mspi->map_rx_dma = 0;
123 }
124 if (t->bits_per_word == 16 && t->tx_buf) {
125 const u16 *src = t->tx_buf;
126 u16 *dst;
127 int i;
128
129 dst = kmalloc(t->len, GFP_KERNEL);
130 if (!dst)
131 return -ENOMEM;
132
133 for (i = 0; i < t->len >> 1; i++)
134 dst[i] = cpu_to_le16p(src + i);
135
136 mspi->tx = dst;
137 mspi->map_tx_dma = 1;
138 }
139
140 if (mspi->map_tx_dma) {
141 void *nonconst_tx = (void *)mspi->tx; /* shut up gcc */
142
143 mspi->tx_dma = dma_map_single(dev, nonconst_tx, t->len,
144 DMA_TO_DEVICE);
145 if (dma_mapping_error(dev, mspi->tx_dma)) {
146 dev_err(dev, "unable to map tx dma\n");
147 return -ENOMEM;
148 }
149 } else if (t->tx_buf) {
150 mspi->tx_dma = t->tx_dma;
151 }
152
153 if (mspi->map_rx_dma) {
154 mspi->rx_dma = dma_map_single(dev, mspi->rx, t->len,
155 DMA_FROM_DEVICE);
156 if (dma_mapping_error(dev, mspi->rx_dma)) {
157 dev_err(dev, "unable to map rx dma\n");
158 goto err_rx_dma;
159 }
160 } else if (t->rx_buf) {
161 mspi->rx_dma = t->rx_dma;
162 }
163
164 /* enable rx ints */
165 mpc8xxx_spi_write_reg(®_base->mask, SPIE_RXB);
166
167 mspi->xfer_in_progress = t;
168 mspi->count = t->len;
169
170 /* start CPM transfers */
171 fsl_spi_cpm_bufs_start(mspi);
172
173 return 0;
174
175 err_rx_dma:
176 if (mspi->map_tx_dma)
177 dma_unmap_single(dev, mspi->tx_dma, t->len, DMA_TO_DEVICE);
178 return -ENOMEM;
179 }
180 EXPORT_SYMBOL_GPL(fsl_spi_cpm_bufs);
181
fsl_spi_cpm_bufs_complete(struct mpc8xxx_spi * mspi)182 void fsl_spi_cpm_bufs_complete(struct mpc8xxx_spi *mspi)
183 {
184 struct device *dev = mspi->dev;
185 struct spi_transfer *t = mspi->xfer_in_progress;
186
187 if (mspi->map_tx_dma)
188 dma_unmap_single(dev, mspi->tx_dma, t->len, DMA_TO_DEVICE);
189 if (mspi->map_rx_dma)
190 dma_unmap_single(dev, mspi->rx_dma, t->len, DMA_FROM_DEVICE);
191 mspi->xfer_in_progress = NULL;
192
193 if (t->bits_per_word == 16 && t->rx_buf) {
194 int i;
195
196 for (i = 0; i < t->len; i += 2)
197 le16_to_cpus(t->rx_buf + i);
198 }
199 }
200 EXPORT_SYMBOL_GPL(fsl_spi_cpm_bufs_complete);
201
fsl_spi_cpm_irq(struct mpc8xxx_spi * mspi,u32 events)202 void fsl_spi_cpm_irq(struct mpc8xxx_spi *mspi, u32 events)
203 {
204 u16 len;
205 struct fsl_spi_reg *reg_base = mspi->reg_base;
206
207 dev_dbg(mspi->dev, "%s: bd datlen %d, count %d\n", __func__,
208 in_be16(&mspi->rx_bd->cbd_datlen), mspi->count);
209
210 len = in_be16(&mspi->rx_bd->cbd_datlen);
211 if (len > mspi->count) {
212 WARN_ON(1);
213 len = mspi->count;
214 }
215
216 /* Clear the events */
217 mpc8xxx_spi_write_reg(®_base->event, events);
218
219 mspi->count -= len;
220 if (mspi->count)
221 fsl_spi_cpm_bufs_start(mspi);
222 else
223 complete(&mspi->done);
224 }
225 EXPORT_SYMBOL_GPL(fsl_spi_cpm_irq);
226
fsl_spi_alloc_dummy_rx(void)227 static void *fsl_spi_alloc_dummy_rx(void)
228 {
229 mutex_lock(&fsl_dummy_rx_lock);
230
231 if (!fsl_dummy_rx)
232 fsl_dummy_rx = kmalloc(SPI_MRBLR, GFP_KERNEL);
233 if (fsl_dummy_rx)
234 fsl_dummy_rx_refcnt++;
235
236 mutex_unlock(&fsl_dummy_rx_lock);
237
238 return fsl_dummy_rx;
239 }
240
fsl_spi_free_dummy_rx(void)241 static void fsl_spi_free_dummy_rx(void)
242 {
243 mutex_lock(&fsl_dummy_rx_lock);
244
245 switch (fsl_dummy_rx_refcnt) {
246 case 0:
247 WARN_ON(1);
248 break;
249 case 1:
250 kfree(fsl_dummy_rx);
251 fsl_dummy_rx = NULL;
252 fallthrough;
253 default:
254 fsl_dummy_rx_refcnt--;
255 break;
256 }
257
258 mutex_unlock(&fsl_dummy_rx_lock);
259 }
260
fsl_spi_cpm_get_pram(struct mpc8xxx_spi * mspi)261 static unsigned long fsl_spi_cpm_get_pram(struct mpc8xxx_spi *mspi)
262 {
263 struct device *dev = mspi->dev;
264 struct device_node *np = dev->of_node;
265 const u32 *iprop;
266 int size;
267 void __iomem *spi_base;
268 unsigned long pram_ofs = -ENOMEM;
269
270 /* Can't use of_address_to_resource(), QE muram isn't at 0. */
271 iprop = of_get_property(np, "reg", &size);
272
273 /* QE with a fixed pram location? */
274 if (mspi->flags & SPI_QE && iprop && size == sizeof(*iprop) * 4)
275 return cpm_muram_alloc_fixed(iprop[2], SPI_PRAM_SIZE);
276
277 /* QE but with a dynamic pram location? */
278 if (mspi->flags & SPI_QE) {
279 pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
280 qe_issue_cmd(QE_ASSIGN_PAGE_TO_DEVICE, mspi->subblock,
281 QE_CR_PROTOCOL_UNSPECIFIED, pram_ofs);
282 return pram_ofs;
283 }
284
285 spi_base = of_iomap(np, 1);
286 if (spi_base == NULL)
287 return -EINVAL;
288
289 if (mspi->flags & SPI_CPM2) {
290 pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
291 out_be16(spi_base, pram_ofs);
292 }
293
294 iounmap(spi_base);
295 return pram_ofs;
296 }
297
fsl_spi_cpm_init(struct mpc8xxx_spi * mspi)298 int fsl_spi_cpm_init(struct mpc8xxx_spi *mspi)
299 {
300 struct device *dev = mspi->dev;
301 struct device_node *np = dev->of_node;
302 const u32 *iprop;
303 int size;
304 unsigned long bds_ofs;
305
306 if (!(mspi->flags & SPI_CPM_MODE))
307 return 0;
308
309 if (!fsl_spi_alloc_dummy_rx())
310 return -ENOMEM;
311
312 if (mspi->flags & SPI_QE) {
313 iprop = of_get_property(np, "cell-index", &size);
314 if (iprop && size == sizeof(*iprop))
315 mspi->subblock = *iprop;
316
317 switch (mspi->subblock) {
318 default:
319 dev_warn(dev, "cell-index unspecified, assuming SPI1\n");
320 fallthrough;
321 case 0:
322 mspi->subblock = QE_CR_SUBBLOCK_SPI1;
323 break;
324 case 1:
325 mspi->subblock = QE_CR_SUBBLOCK_SPI2;
326 break;
327 }
328 }
329
330 if (mspi->flags & SPI_CPM1) {
331 void *pram;
332
333 pram = devm_platform_ioremap_resource(to_platform_device(dev),
334 1);
335 if (IS_ERR(pram))
336 mspi->pram = NULL;
337 else
338 mspi->pram = pram;
339 } else {
340 unsigned long pram_ofs = fsl_spi_cpm_get_pram(mspi);
341
342 if (IS_ERR_VALUE(pram_ofs))
343 mspi->pram = NULL;
344 else
345 mspi->pram = cpm_muram_addr(pram_ofs);
346 }
347 if (mspi->pram == NULL) {
348 dev_err(dev, "can't allocate spi parameter ram\n");
349 goto err_pram;
350 }
351
352 bds_ofs = cpm_muram_alloc(sizeof(*mspi->tx_bd) +
353 sizeof(*mspi->rx_bd), 8);
354 if (IS_ERR_VALUE(bds_ofs)) {
355 dev_err(dev, "can't allocate bds\n");
356 goto err_bds;
357 }
358
359 mspi->dma_dummy_tx = dma_map_single(dev, empty_zero_page, PAGE_SIZE,
360 DMA_TO_DEVICE);
361 if (dma_mapping_error(dev, mspi->dma_dummy_tx)) {
362 dev_err(dev, "unable to map dummy tx buffer\n");
363 goto err_dummy_tx;
364 }
365
366 mspi->dma_dummy_rx = dma_map_single(dev, fsl_dummy_rx, SPI_MRBLR,
367 DMA_FROM_DEVICE);
368 if (dma_mapping_error(dev, mspi->dma_dummy_rx)) {
369 dev_err(dev, "unable to map dummy rx buffer\n");
370 goto err_dummy_rx;
371 }
372
373 mspi->tx_bd = cpm_muram_addr(bds_ofs);
374 mspi->rx_bd = cpm_muram_addr(bds_ofs + sizeof(*mspi->tx_bd));
375
376 /* Initialize parameter ram. */
377 out_be16(&mspi->pram->tbase, cpm_muram_offset(mspi->tx_bd));
378 out_be16(&mspi->pram->rbase, cpm_muram_offset(mspi->rx_bd));
379 out_8(&mspi->pram->tfcr, CPMFCR_EB | CPMFCR_GBL);
380 out_8(&mspi->pram->rfcr, CPMFCR_EB | CPMFCR_GBL);
381 out_be16(&mspi->pram->mrblr, SPI_MRBLR);
382 out_be32(&mspi->pram->rstate, 0);
383 out_be32(&mspi->pram->rdp, 0);
384 out_be16(&mspi->pram->rbptr, 0);
385 out_be16(&mspi->pram->rbc, 0);
386 out_be32(&mspi->pram->rxtmp, 0);
387 out_be32(&mspi->pram->tstate, 0);
388 out_be32(&mspi->pram->tdp, 0);
389 out_be16(&mspi->pram->tbptr, 0);
390 out_be16(&mspi->pram->tbc, 0);
391 out_be32(&mspi->pram->txtmp, 0);
392
393 return 0;
394
395 err_dummy_rx:
396 dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
397 err_dummy_tx:
398 cpm_muram_free(bds_ofs);
399 err_bds:
400 if (!(mspi->flags & SPI_CPM1))
401 cpm_muram_free(cpm_muram_offset(mspi->pram));
402 err_pram:
403 fsl_spi_free_dummy_rx();
404 return -ENOMEM;
405 }
406 EXPORT_SYMBOL_GPL(fsl_spi_cpm_init);
407
fsl_spi_cpm_free(struct mpc8xxx_spi * mspi)408 void fsl_spi_cpm_free(struct mpc8xxx_spi *mspi)
409 {
410 struct device *dev = mspi->dev;
411
412 if (!(mspi->flags & SPI_CPM_MODE))
413 return;
414
415 dma_unmap_single(dev, mspi->dma_dummy_rx, SPI_MRBLR, DMA_FROM_DEVICE);
416 dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
417 cpm_muram_free(cpm_muram_offset(mspi->tx_bd));
418 if (!(mspi->flags & SPI_CPM1))
419 cpm_muram_free(cpm_muram_offset(mspi->pram));
420 fsl_spi_free_dummy_rx();
421 }
422 EXPORT_SYMBOL_GPL(fsl_spi_cpm_free);
423
424 MODULE_LICENSE("GPL");
425