1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
4 *
5 * Derived from linux/drivers/spi/spi-bcm63xx.c:
6 * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org>
7 * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
8 */
9
10 #include <common.h>
11 #include <clk.h>
12 #include <dm.h>
13 #include <spi.h>
14 #include <reset.h>
15 #include <wait_bit.h>
16 #include <asm/io.h>
17
18 /* BCM6348 SPI core */
19 #define SPI_6348_CLK 0x06
20 #define SPI_6348_CMD 0x00
21 #define SPI_6348_CTL 0x40
22 #define SPI_6348_CTL_SHIFT 6
23 #define SPI_6348_FILL 0x07
24 #define SPI_6348_IR_MASK 0x04
25 #define SPI_6348_IR_STAT 0x02
26 #define SPI_6348_RX 0x80
27 #define SPI_6348_RX_SIZE 0x3f
28 #define SPI_6348_TX 0x41
29 #define SPI_6348_TX_SIZE 0x3f
30
31 /* BCM6358 SPI core */
32 #define SPI_6358_CLK 0x706
33 #define SPI_6358_CMD 0x700
34 #define SPI_6358_CTL 0x000
35 #define SPI_6358_CTL_SHIFT 14
36 #define SPI_6358_FILL 0x707
37 #define SPI_6358_IR_MASK 0x702
38 #define SPI_6358_IR_STAT 0x704
39 #define SPI_6358_RX 0x400
40 #define SPI_6358_RX_SIZE 0x220
41 #define SPI_6358_TX 0x002
42 #define SPI_6358_TX_SIZE 0x21e
43
44 /* SPI Clock register */
45 #define SPI_CLK_SHIFT 0
46 #define SPI_CLK_20MHZ (0 << SPI_CLK_SHIFT)
47 #define SPI_CLK_0_391MHZ (1 << SPI_CLK_SHIFT)
48 #define SPI_CLK_0_781MHZ (2 << SPI_CLK_SHIFT)
49 #define SPI_CLK_1_563MHZ (3 << SPI_CLK_SHIFT)
50 #define SPI_CLK_3_125MHZ (4 << SPI_CLK_SHIFT)
51 #define SPI_CLK_6_250MHZ (5 << SPI_CLK_SHIFT)
52 #define SPI_CLK_12_50MHZ (6 << SPI_CLK_SHIFT)
53 #define SPI_CLK_25MHZ (7 << SPI_CLK_SHIFT)
54 #define SPI_CLK_MASK (7 << SPI_CLK_SHIFT)
55 #define SPI_CLK_SSOFF_SHIFT 3
56 #define SPI_CLK_SSOFF_2 (2 << SPI_CLK_SSOFF_SHIFT)
57 #define SPI_CLK_SSOFF_MASK (7 << SPI_CLK_SSOFF_SHIFT)
58 #define SPI_CLK_BSWAP_SHIFT 7
59 #define SPI_CLK_BSWAP_MASK (1 << SPI_CLK_BSWAP_SHIFT)
60
61 /* SPI Command register */
62 #define SPI_CMD_OP_SHIFT 0
63 #define SPI_CMD_OP_START (0x3 << SPI_CMD_OP_SHIFT)
64 #define SPI_CMD_SLAVE_SHIFT 4
65 #define SPI_CMD_SLAVE_MASK (0xf << SPI_CMD_SLAVE_SHIFT)
66 #define SPI_CMD_PREPEND_SHIFT 8
67 #define SPI_CMD_PREPEND_BYTES 0xf
68 #define SPI_CMD_3WIRE_SHIFT 12
69 #define SPI_CMD_3WIRE_MASK (1 << SPI_CMD_3WIRE_SHIFT)
70
71 /* SPI Control register */
72 #define SPI_CTL_TYPE_FD_RW 0
73 #define SPI_CTL_TYPE_HD_W 1
74 #define SPI_CTL_TYPE_HD_R 2
75
76 /* SPI Interrupt registers */
77 #define SPI_IR_DONE_SHIFT 0
78 #define SPI_IR_DONE_MASK (1 << SPI_IR_DONE_SHIFT)
79 #define SPI_IR_RXOVER_SHIFT 1
80 #define SPI_IR_RXOVER_MASK (1 << SPI_IR_RXOVER_SHIFT)
81 #define SPI_IR_TXUNDER_SHIFT 2
82 #define SPI_IR_TXUNDER_MASK (1 << SPI_IR_TXUNDER_SHIFT)
83 #define SPI_IR_TXOVER_SHIFT 3
84 #define SPI_IR_TXOVER_MASK (1 << SPI_IR_TXOVER_SHIFT)
85 #define SPI_IR_RXUNDER_SHIFT 4
86 #define SPI_IR_RXUNDER_MASK (1 << SPI_IR_RXUNDER_SHIFT)
87 #define SPI_IR_CLEAR_MASK (SPI_IR_DONE_MASK |\
88 SPI_IR_RXOVER_MASK |\
89 SPI_IR_TXUNDER_MASK |\
90 SPI_IR_TXOVER_MASK |\
91 SPI_IR_RXUNDER_MASK)
92
93 enum bcm63xx_regs_spi {
94 SPI_CLK,
95 SPI_CMD,
96 SPI_CTL,
97 SPI_CTL_SHIFT,
98 SPI_FILL,
99 SPI_IR_MASK,
100 SPI_IR_STAT,
101 SPI_RX,
102 SPI_RX_SIZE,
103 SPI_TX,
104 SPI_TX_SIZE,
105 };
106
107 struct bcm63xx_spi_priv {
108 const unsigned long *regs;
109 void __iomem *base;
110 size_t tx_bytes;
111 uint8_t num_cs;
112 };
113
114 #define SPI_CLK_CNT 8
115 static const unsigned bcm63xx_spi_freq_table[SPI_CLK_CNT][2] = {
116 { 25000000, SPI_CLK_25MHZ },
117 { 20000000, SPI_CLK_20MHZ },
118 { 12500000, SPI_CLK_12_50MHZ },
119 { 6250000, SPI_CLK_6_250MHZ },
120 { 3125000, SPI_CLK_3_125MHZ },
121 { 1563000, SPI_CLK_1_563MHZ },
122 { 781000, SPI_CLK_0_781MHZ },
123 { 391000, SPI_CLK_0_391MHZ }
124 };
125
bcm63xx_spi_cs_info(struct udevice * bus,uint cs,struct spi_cs_info * info)126 static int bcm63xx_spi_cs_info(struct udevice *bus, uint cs,
127 struct spi_cs_info *info)
128 {
129 struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
130
131 if (cs >= priv->num_cs) {
132 printf("no cs %u\n", cs);
133 return -ENODEV;
134 }
135
136 return 0;
137 }
138
bcm63xx_spi_set_mode(struct udevice * bus,uint mode)139 static int bcm63xx_spi_set_mode(struct udevice *bus, uint mode)
140 {
141 struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
142 const unsigned long *regs = priv->regs;
143
144 if (mode & SPI_LSB_FIRST)
145 setbits_8(priv->base + regs[SPI_CLK], SPI_CLK_BSWAP_MASK);
146 else
147 clrbits_8(priv->base + regs[SPI_CLK], SPI_CLK_BSWAP_MASK);
148
149 return 0;
150 }
151
bcm63xx_spi_set_speed(struct udevice * bus,uint speed)152 static int bcm63xx_spi_set_speed(struct udevice *bus, uint speed)
153 {
154 struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
155 const unsigned long *regs = priv->regs;
156 uint8_t clk_cfg;
157 int i;
158
159 /* default to lowest clock configuration */
160 clk_cfg = SPI_CLK_0_391MHZ;
161
162 /* find the closest clock configuration */
163 for (i = 0; i < SPI_CLK_CNT; i++) {
164 if (speed >= bcm63xx_spi_freq_table[i][0]) {
165 clk_cfg = bcm63xx_spi_freq_table[i][1];
166 break;
167 }
168 }
169
170 /* write clock configuration */
171 clrsetbits_8(priv->base + regs[SPI_CLK],
172 SPI_CLK_SSOFF_MASK | SPI_CLK_MASK,
173 clk_cfg | SPI_CLK_SSOFF_2);
174
175 return 0;
176 }
177
178 /*
179 * BCM63xx SPI driver doesn't allow keeping CS active between transfers since
180 * they are HW controlled.
181 * However, it provides a mechanism to prepend write transfers prior to read
182 * transfers (with a maximum prepend of 15 bytes), which is usually enough for
183 * SPI-connected flashes since reading requires prepending a write transfer of
184 * 5 bytes.
185 *
186 * This implementation takes advantage of the prepend mechanism and combines
187 * multiple transfers into a single one where possible (single/multiple write
188 * transfer(s) followed by a final read/write transfer).
189 * However, it's not possible to buffer reads, which means that read transfers
190 * should always be done as the final ones.
191 * On the other hand, take into account that combining write transfers into
192 * a single one is just buffering and doesn't require prepend mechanism.
193 */
bcm63xx_spi_xfer(struct udevice * dev,unsigned int bitlen,const void * dout,void * din,unsigned long flags)194 static int bcm63xx_spi_xfer(struct udevice *dev, unsigned int bitlen,
195 const void *dout, void *din, unsigned long flags)
196 {
197 struct bcm63xx_spi_priv *priv = dev_get_priv(dev->parent);
198 const unsigned long *regs = priv->regs;
199 size_t data_bytes = bitlen / 8;
200
201 if (flags & SPI_XFER_BEGIN) {
202 /* clear prepends */
203 priv->tx_bytes = 0;
204
205 /* initialize hardware */
206 writeb_be(0, priv->base + regs[SPI_IR_MASK]);
207 }
208
209 if (din) {
210 /* buffering reads not possible since cs is hw controlled */
211 if (!(flags & SPI_XFER_END)) {
212 printf("unable to buffer reads\n");
213 return -EINVAL;
214 }
215
216 /* check rx size */
217 if (data_bytes > regs[SPI_RX_SIZE]) {
218 printf("max rx bytes exceeded\n");
219 return -EMSGSIZE;
220 }
221 }
222
223 if (dout) {
224 /* check tx size */
225 if (priv->tx_bytes + data_bytes > regs[SPI_TX_SIZE]) {
226 printf("max tx bytes exceeded\n");
227 return -EMSGSIZE;
228 }
229
230 /* copy tx data */
231 memcpy_toio(priv->base + regs[SPI_TX] + priv->tx_bytes,
232 dout, data_bytes);
233 priv->tx_bytes += data_bytes;
234 }
235
236 if (flags & SPI_XFER_END) {
237 struct dm_spi_slave_platdata *plat =
238 dev_get_parent_platdata(dev);
239 uint16_t val, cmd;
240 int ret;
241
242 /* determine control config */
243 if (dout && !din) {
244 /* buffered write transfers */
245 val = priv->tx_bytes;
246 val |= (SPI_CTL_TYPE_HD_W << regs[SPI_CTL_SHIFT]);
247 priv->tx_bytes = 0;
248 } else {
249 if (dout && din && (flags & SPI_XFER_ONCE)) {
250 /* full duplex read/write */
251 val = data_bytes;
252 val |= (SPI_CTL_TYPE_FD_RW <<
253 regs[SPI_CTL_SHIFT]);
254 priv->tx_bytes = 0;
255 } else {
256 /* prepended write transfer */
257 val = data_bytes;
258 val |= (SPI_CTL_TYPE_HD_R <<
259 regs[SPI_CTL_SHIFT]);
260 if (priv->tx_bytes > SPI_CMD_PREPEND_BYTES) {
261 printf("max prepend bytes exceeded\n");
262 return -EMSGSIZE;
263 }
264 }
265 }
266
267 if (regs[SPI_CTL_SHIFT] >= 8)
268 writew_be(val, priv->base + regs[SPI_CTL]);
269 else
270 writeb_be(val, priv->base + regs[SPI_CTL]);
271
272 /* clear interrupts */
273 writeb_be(SPI_IR_CLEAR_MASK, priv->base + regs[SPI_IR_STAT]);
274
275 /* issue the transfer */
276 cmd = SPI_CMD_OP_START;
277 cmd |= (plat->cs << SPI_CMD_SLAVE_SHIFT) & SPI_CMD_SLAVE_MASK;
278 cmd |= (priv->tx_bytes << SPI_CMD_PREPEND_SHIFT);
279 if (plat->mode & SPI_3WIRE)
280 cmd |= SPI_CMD_3WIRE_MASK;
281 writew_be(cmd, priv->base + regs[SPI_CMD]);
282
283 /* enable interrupts */
284 writeb_be(SPI_IR_DONE_MASK, priv->base + regs[SPI_IR_MASK]);
285
286 ret = wait_for_bit_8(priv->base + regs[SPI_IR_STAT],
287 SPI_IR_DONE_MASK, true, 1000, false);
288 if (ret) {
289 printf("interrupt timeout\n");
290 return ret;
291 }
292
293 /* copy rx data */
294 if (din)
295 memcpy_fromio(din, priv->base + regs[SPI_RX],
296 data_bytes);
297 }
298
299 return 0;
300 }
301
302 static const struct dm_spi_ops bcm63xx_spi_ops = {
303 .cs_info = bcm63xx_spi_cs_info,
304 .set_mode = bcm63xx_spi_set_mode,
305 .set_speed = bcm63xx_spi_set_speed,
306 .xfer = bcm63xx_spi_xfer,
307 };
308
309 static const unsigned long bcm6348_spi_regs[] = {
310 [SPI_CLK] = SPI_6348_CLK,
311 [SPI_CMD] = SPI_6348_CMD,
312 [SPI_CTL] = SPI_6348_CTL,
313 [SPI_CTL_SHIFT] = SPI_6348_CTL_SHIFT,
314 [SPI_FILL] = SPI_6348_FILL,
315 [SPI_IR_MASK] = SPI_6348_IR_MASK,
316 [SPI_IR_STAT] = SPI_6348_IR_STAT,
317 [SPI_RX] = SPI_6348_RX,
318 [SPI_RX_SIZE] = SPI_6348_RX_SIZE,
319 [SPI_TX] = SPI_6348_TX,
320 [SPI_TX_SIZE] = SPI_6348_TX_SIZE,
321 };
322
323 static const unsigned long bcm6358_spi_regs[] = {
324 [SPI_CLK] = SPI_6358_CLK,
325 [SPI_CMD] = SPI_6358_CMD,
326 [SPI_CTL] = SPI_6358_CTL,
327 [SPI_CTL_SHIFT] = SPI_6358_CTL_SHIFT,
328 [SPI_FILL] = SPI_6358_FILL,
329 [SPI_IR_MASK] = SPI_6358_IR_MASK,
330 [SPI_IR_STAT] = SPI_6358_IR_STAT,
331 [SPI_RX] = SPI_6358_RX,
332 [SPI_RX_SIZE] = SPI_6358_RX_SIZE,
333 [SPI_TX] = SPI_6358_TX,
334 [SPI_TX_SIZE] = SPI_6358_TX_SIZE,
335 };
336
337 static const struct udevice_id bcm63xx_spi_ids[] = {
338 {
339 .compatible = "brcm,bcm6348-spi",
340 .data = (ulong)&bcm6348_spi_regs,
341 }, {
342 .compatible = "brcm,bcm6358-spi",
343 .data = (ulong)&bcm6358_spi_regs,
344 }, { /* sentinel */ }
345 };
346
bcm63xx_spi_child_pre_probe(struct udevice * dev)347 static int bcm63xx_spi_child_pre_probe(struct udevice *dev)
348 {
349 struct bcm63xx_spi_priv *priv = dev_get_priv(dev->parent);
350 const unsigned long *regs = priv->regs;
351 struct spi_slave *slave = dev_get_parent_priv(dev);
352 struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
353
354 /* check cs */
355 if (plat->cs >= priv->num_cs) {
356 printf("no cs %u\n", plat->cs);
357 return -ENODEV;
358 }
359
360 /* max read/write sizes */
361 slave->max_read_size = regs[SPI_RX_SIZE];
362 slave->max_write_size = regs[SPI_TX_SIZE];
363
364 return 0;
365 }
366
bcm63xx_spi_probe(struct udevice * dev)367 static int bcm63xx_spi_probe(struct udevice *dev)
368 {
369 struct bcm63xx_spi_priv *priv = dev_get_priv(dev);
370 const unsigned long *regs =
371 (const unsigned long *)dev_get_driver_data(dev);
372 struct reset_ctl rst_ctl;
373 struct clk clk;
374 int ret;
375
376 priv->base = dev_remap_addr(dev);
377 if (!priv->base)
378 return -EINVAL;
379
380 priv->regs = regs;
381 priv->num_cs = dev_read_u32_default(dev, "num-cs", 8);
382
383 /* enable clock */
384 ret = clk_get_by_index(dev, 0, &clk);
385 if (ret < 0)
386 return ret;
387
388 ret = clk_enable(&clk);
389 if (ret < 0)
390 return ret;
391
392 ret = clk_free(&clk);
393 if (ret < 0)
394 return ret;
395
396 /* perform reset */
397 ret = reset_get_by_index(dev, 0, &rst_ctl);
398 if (ret < 0)
399 return ret;
400
401 ret = reset_deassert(&rst_ctl);
402 if (ret < 0)
403 return ret;
404
405 ret = reset_free(&rst_ctl);
406 if (ret < 0)
407 return ret;
408
409 /* initialize hardware */
410 writeb_be(0, priv->base + regs[SPI_IR_MASK]);
411
412 /* set fill register */
413 writeb_be(0xff, priv->base + regs[SPI_FILL]);
414
415 return 0;
416 }
417
418 U_BOOT_DRIVER(bcm63xx_spi) = {
419 .name = "bcm63xx_spi",
420 .id = UCLASS_SPI,
421 .of_match = bcm63xx_spi_ids,
422 .ops = &bcm63xx_spi_ops,
423 .priv_auto_alloc_size = sizeof(struct bcm63xx_spi_priv),
424 .child_pre_probe = bcm63xx_spi_child_pre_probe,
425 .probe = bcm63xx_spi_probe,
426 };
427