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