1 /*
2 * Copyright (c) 2015 MediaTek Inc.
3 * Author: Bayi Cheng <bayi.cheng@mediatek.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15 #include <linux/clk.h>
16 #include <linux/delay.h>
17 #include <linux/device.h>
18 #include <linux/init.h>
19 #include <linux/io.h>
20 #include <linux/iopoll.h>
21 #include <linux/ioport.h>
22 #include <linux/math64.h>
23 #include <linux/module.h>
24 #include <linux/mutex.h>
25 #include <linux/of.h>
26 #include <linux/of_device.h>
27 #include <linux/pinctrl/consumer.h>
28 #include <linux/platform_device.h>
29 #include <linux/slab.h>
30 #include <linux/mtd/mtd.h>
31 #include <linux/mtd/partitions.h>
32 #include <linux/mtd/spi-nor.h>
33
34 #define MTK_NOR_CMD_REG 0x00
35 #define MTK_NOR_CNT_REG 0x04
36 #define MTK_NOR_RDSR_REG 0x08
37 #define MTK_NOR_RDATA_REG 0x0c
38 #define MTK_NOR_RADR0_REG 0x10
39 #define MTK_NOR_RADR1_REG 0x14
40 #define MTK_NOR_RADR2_REG 0x18
41 #define MTK_NOR_WDATA_REG 0x1c
42 #define MTK_NOR_PRGDATA0_REG 0x20
43 #define MTK_NOR_PRGDATA1_REG 0x24
44 #define MTK_NOR_PRGDATA2_REG 0x28
45 #define MTK_NOR_PRGDATA3_REG 0x2c
46 #define MTK_NOR_PRGDATA4_REG 0x30
47 #define MTK_NOR_PRGDATA5_REG 0x34
48 #define MTK_NOR_SHREG0_REG 0x38
49 #define MTK_NOR_SHREG1_REG 0x3c
50 #define MTK_NOR_SHREG2_REG 0x40
51 #define MTK_NOR_SHREG3_REG 0x44
52 #define MTK_NOR_SHREG4_REG 0x48
53 #define MTK_NOR_SHREG5_REG 0x4c
54 #define MTK_NOR_SHREG6_REG 0x50
55 #define MTK_NOR_SHREG7_REG 0x54
56 #define MTK_NOR_SHREG8_REG 0x58
57 #define MTK_NOR_SHREG9_REG 0x5c
58 #define MTK_NOR_CFG1_REG 0x60
59 #define MTK_NOR_CFG2_REG 0x64
60 #define MTK_NOR_CFG3_REG 0x68
61 #define MTK_NOR_STATUS0_REG 0x70
62 #define MTK_NOR_STATUS1_REG 0x74
63 #define MTK_NOR_STATUS2_REG 0x78
64 #define MTK_NOR_STATUS3_REG 0x7c
65 #define MTK_NOR_FLHCFG_REG 0x84
66 #define MTK_NOR_TIME_REG 0x94
67 #define MTK_NOR_PP_DATA_REG 0x98
68 #define MTK_NOR_PREBUF_STUS_REG 0x9c
69 #define MTK_NOR_DELSEL0_REG 0xa0
70 #define MTK_NOR_DELSEL1_REG 0xa4
71 #define MTK_NOR_INTRSTUS_REG 0xa8
72 #define MTK_NOR_INTREN_REG 0xac
73 #define MTK_NOR_CHKSUM_CTL_REG 0xb8
74 #define MTK_NOR_CHKSUM_REG 0xbc
75 #define MTK_NOR_CMD2_REG 0xc0
76 #define MTK_NOR_WRPROT_REG 0xc4
77 #define MTK_NOR_RADR3_REG 0xc8
78 #define MTK_NOR_DUAL_REG 0xcc
79 #define MTK_NOR_DELSEL2_REG 0xd0
80 #define MTK_NOR_DELSEL3_REG 0xd4
81 #define MTK_NOR_DELSEL4_REG 0xd8
82
83 /* commands for mtk nor controller */
84 #define MTK_NOR_READ_CMD 0x0
85 #define MTK_NOR_RDSR_CMD 0x2
86 #define MTK_NOR_PRG_CMD 0x4
87 #define MTK_NOR_WR_CMD 0x10
88 #define MTK_NOR_PIO_WR_CMD 0x90
89 #define MTK_NOR_WRSR_CMD 0x20
90 #define MTK_NOR_PIO_READ_CMD 0x81
91 #define MTK_NOR_WR_BUF_ENABLE 0x1
92 #define MTK_NOR_WR_BUF_DISABLE 0x0
93 #define MTK_NOR_ENABLE_SF_CMD 0x30
94 #define MTK_NOR_DUAD_ADDR_EN 0x8
95 #define MTK_NOR_QUAD_READ_EN 0x4
96 #define MTK_NOR_DUAL_ADDR_EN 0x2
97 #define MTK_NOR_DUAL_READ_EN 0x1
98 #define MTK_NOR_DUAL_DISABLE 0x0
99 #define MTK_NOR_FAST_READ 0x1
100
101 #define SFLASH_WRBUF_SIZE 128
102
103 /* Can shift up to 48 bits (6 bytes) of TX/RX */
104 #define MTK_NOR_MAX_RX_TX_SHIFT 6
105 /* can shift up to 56 bits (7 bytes) transfer by MTK_NOR_PRG_CMD */
106 #define MTK_NOR_MAX_SHIFT 7
107
108 /* Helpers for accessing the program data / shift data registers */
109 #define MTK_NOR_PRG_REG(n) (MTK_NOR_PRGDATA0_REG + 4 * (n))
110 #define MTK_NOR_SHREG(n) (MTK_NOR_SHREG0_REG + 4 * (n))
111
112 struct mt8173_nor {
113 struct spi_nor nor;
114 struct device *dev;
115 void __iomem *base; /* nor flash base address */
116 struct clk *spi_clk;
117 struct clk *nor_clk;
118 };
119
mt8173_nor_set_read_mode(struct mt8173_nor * mt8173_nor)120 static void mt8173_nor_set_read_mode(struct mt8173_nor *mt8173_nor)
121 {
122 struct spi_nor *nor = &mt8173_nor->nor;
123
124 switch (nor->flash_read) {
125 case SPI_NOR_FAST:
126 writeb(nor->read_opcode, mt8173_nor->base +
127 MTK_NOR_PRGDATA3_REG);
128 writeb(MTK_NOR_FAST_READ, mt8173_nor->base +
129 MTK_NOR_CFG1_REG);
130 break;
131 case SPI_NOR_DUAL:
132 writeb(nor->read_opcode, mt8173_nor->base +
133 MTK_NOR_PRGDATA3_REG);
134 writeb(MTK_NOR_DUAL_READ_EN, mt8173_nor->base +
135 MTK_NOR_DUAL_REG);
136 break;
137 case SPI_NOR_QUAD:
138 writeb(nor->read_opcode, mt8173_nor->base +
139 MTK_NOR_PRGDATA4_REG);
140 writeb(MTK_NOR_QUAD_READ_EN, mt8173_nor->base +
141 MTK_NOR_DUAL_REG);
142 break;
143 default:
144 writeb(MTK_NOR_DUAL_DISABLE, mt8173_nor->base +
145 MTK_NOR_DUAL_REG);
146 break;
147 }
148 }
149
mt8173_nor_execute_cmd(struct mt8173_nor * mt8173_nor,u8 cmdval)150 static int mt8173_nor_execute_cmd(struct mt8173_nor *mt8173_nor, u8 cmdval)
151 {
152 int reg;
153 u8 val = cmdval & 0x1f;
154
155 writeb(cmdval, mt8173_nor->base + MTK_NOR_CMD_REG);
156 return readl_poll_timeout(mt8173_nor->base + MTK_NOR_CMD_REG, reg,
157 !(reg & val), 100, 10000);
158 }
159
mt8173_nor_do_tx_rx(struct mt8173_nor * mt8173_nor,u8 op,u8 * tx,int txlen,u8 * rx,int rxlen)160 static int mt8173_nor_do_tx_rx(struct mt8173_nor *mt8173_nor, u8 op,
161 u8 *tx, int txlen, u8 *rx, int rxlen)
162 {
163 int len = 1 + txlen + rxlen;
164 int i, ret, idx;
165
166 if (len > MTK_NOR_MAX_SHIFT)
167 return -EINVAL;
168
169 writeb(len * 8, mt8173_nor->base + MTK_NOR_CNT_REG);
170
171 /* start at PRGDATA5, go down to PRGDATA0 */
172 idx = MTK_NOR_MAX_RX_TX_SHIFT - 1;
173
174 /* opcode */
175 writeb(op, mt8173_nor->base + MTK_NOR_PRG_REG(idx));
176 idx--;
177
178 /* program TX data */
179 for (i = 0; i < txlen; i++, idx--)
180 writeb(tx[i], mt8173_nor->base + MTK_NOR_PRG_REG(idx));
181
182 /* clear out rest of TX registers */
183 while (idx >= 0) {
184 writeb(0, mt8173_nor->base + MTK_NOR_PRG_REG(idx));
185 idx--;
186 }
187
188 ret = mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_PRG_CMD);
189 if (ret)
190 return ret;
191
192 /* restart at first RX byte */
193 idx = rxlen - 1;
194
195 /* read out RX data */
196 for (i = 0; i < rxlen; i++, idx--)
197 rx[i] = readb(mt8173_nor->base + MTK_NOR_SHREG(idx));
198
199 return 0;
200 }
201
202 /* Do a WRSR (Write Status Register) command */
mt8173_nor_wr_sr(struct mt8173_nor * mt8173_nor,u8 sr)203 static int mt8173_nor_wr_sr(struct mt8173_nor *mt8173_nor, u8 sr)
204 {
205 writeb(sr, mt8173_nor->base + MTK_NOR_PRGDATA5_REG);
206 writeb(8, mt8173_nor->base + MTK_NOR_CNT_REG);
207 return mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_WRSR_CMD);
208 }
209
mt8173_nor_write_buffer_enable(struct mt8173_nor * mt8173_nor)210 static int mt8173_nor_write_buffer_enable(struct mt8173_nor *mt8173_nor)
211 {
212 u8 reg;
213
214 /* the bit0 of MTK_NOR_CFG2_REG is pre-fetch buffer
215 * 0: pre-fetch buffer use for read
216 * 1: pre-fetch buffer use for page program
217 */
218 writel(MTK_NOR_WR_BUF_ENABLE, mt8173_nor->base + MTK_NOR_CFG2_REG);
219 return readb_poll_timeout(mt8173_nor->base + MTK_NOR_CFG2_REG, reg,
220 0x01 == (reg & 0x01), 100, 10000);
221 }
222
mt8173_nor_write_buffer_disable(struct mt8173_nor * mt8173_nor)223 static int mt8173_nor_write_buffer_disable(struct mt8173_nor *mt8173_nor)
224 {
225 u8 reg;
226
227 writel(MTK_NOR_WR_BUF_DISABLE, mt8173_nor->base + MTK_NOR_CFG2_REG);
228 return readb_poll_timeout(mt8173_nor->base + MTK_NOR_CFG2_REG, reg,
229 MTK_NOR_WR_BUF_DISABLE == (reg & 0x1), 100,
230 10000);
231 }
232
mt8173_nor_set_addr(struct mt8173_nor * mt8173_nor,u32 addr)233 static void mt8173_nor_set_addr(struct mt8173_nor *mt8173_nor, u32 addr)
234 {
235 int i;
236
237 for (i = 0; i < 3; i++) {
238 writeb(addr & 0xff, mt8173_nor->base + MTK_NOR_RADR0_REG + i * 4);
239 addr >>= 8;
240 }
241 /* Last register is non-contiguous */
242 writeb(addr & 0xff, mt8173_nor->base + MTK_NOR_RADR3_REG);
243 }
244
mt8173_nor_read(struct spi_nor * nor,loff_t from,size_t length,u_char * buffer)245 static ssize_t mt8173_nor_read(struct spi_nor *nor, loff_t from, size_t length,
246 u_char *buffer)
247 {
248 int i, ret;
249 int addr = (int)from;
250 u8 *buf = (u8 *)buffer;
251 struct mt8173_nor *mt8173_nor = nor->priv;
252
253 /* set mode for fast read mode ,dual mode or quad mode */
254 mt8173_nor_set_read_mode(mt8173_nor);
255 mt8173_nor_set_addr(mt8173_nor, addr);
256
257 for (i = 0; i < length; i++) {
258 ret = mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_PIO_READ_CMD);
259 if (ret < 0)
260 return ret;
261 buf[i] = readb(mt8173_nor->base + MTK_NOR_RDATA_REG);
262 }
263 return length;
264 }
265
mt8173_nor_write_single_byte(struct mt8173_nor * mt8173_nor,int addr,int length,u8 * data)266 static int mt8173_nor_write_single_byte(struct mt8173_nor *mt8173_nor,
267 int addr, int length, u8 *data)
268 {
269 int i, ret;
270
271 mt8173_nor_set_addr(mt8173_nor, addr);
272
273 for (i = 0; i < length; i++) {
274 writeb(*data++, mt8173_nor->base + MTK_NOR_WDATA_REG);
275 ret = mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_PIO_WR_CMD);
276 if (ret < 0)
277 return ret;
278 }
279 return 0;
280 }
281
mt8173_nor_write_buffer(struct mt8173_nor * mt8173_nor,int addr,const u8 * buf)282 static int mt8173_nor_write_buffer(struct mt8173_nor *mt8173_nor, int addr,
283 const u8 *buf)
284 {
285 int i, bufidx, data;
286
287 mt8173_nor_set_addr(mt8173_nor, addr);
288
289 bufidx = 0;
290 for (i = 0; i < SFLASH_WRBUF_SIZE; i += 4) {
291 data = buf[bufidx + 3]<<24 | buf[bufidx + 2]<<16 |
292 buf[bufidx + 1]<<8 | buf[bufidx];
293 bufidx += 4;
294 writel(data, mt8173_nor->base + MTK_NOR_PP_DATA_REG);
295 }
296 return mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_WR_CMD);
297 }
298
mt8173_nor_write(struct spi_nor * nor,loff_t to,size_t len,const u_char * buf)299 static ssize_t mt8173_nor_write(struct spi_nor *nor, loff_t to, size_t len,
300 const u_char *buf)
301 {
302 int ret;
303 struct mt8173_nor *mt8173_nor = nor->priv;
304 size_t i;
305
306 ret = mt8173_nor_write_buffer_enable(mt8173_nor);
307 if (ret < 0) {
308 dev_warn(mt8173_nor->dev, "write buffer enable failed!\n");
309 return ret;
310 }
311
312 for (i = 0; i + SFLASH_WRBUF_SIZE <= len; i += SFLASH_WRBUF_SIZE) {
313 ret = mt8173_nor_write_buffer(mt8173_nor, to, buf);
314 if (ret < 0) {
315 dev_err(mt8173_nor->dev, "write buffer failed!\n");
316 return ret;
317 }
318 to += SFLASH_WRBUF_SIZE;
319 buf += SFLASH_WRBUF_SIZE;
320 }
321 ret = mt8173_nor_write_buffer_disable(mt8173_nor);
322 if (ret < 0) {
323 dev_warn(mt8173_nor->dev, "write buffer disable failed!\n");
324 return ret;
325 }
326
327 if (i < len) {
328 ret = mt8173_nor_write_single_byte(mt8173_nor, to,
329 (int)(len - i), (u8 *)buf);
330 if (ret < 0) {
331 dev_err(mt8173_nor->dev, "write single byte failed!\n");
332 return ret;
333 }
334 }
335
336 return len;
337 }
338
mt8173_nor_read_reg(struct spi_nor * nor,u8 opcode,u8 * buf,int len)339 static int mt8173_nor_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
340 {
341 int ret;
342 struct mt8173_nor *mt8173_nor = nor->priv;
343
344 switch (opcode) {
345 case SPINOR_OP_RDSR:
346 ret = mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_RDSR_CMD);
347 if (ret < 0)
348 return ret;
349 if (len == 1)
350 *buf = readb(mt8173_nor->base + MTK_NOR_RDSR_REG);
351 else
352 dev_err(mt8173_nor->dev, "len should be 1 for read status!\n");
353 break;
354 default:
355 ret = mt8173_nor_do_tx_rx(mt8173_nor, opcode, NULL, 0, buf, len);
356 break;
357 }
358 return ret;
359 }
360
mt8173_nor_write_reg(struct spi_nor * nor,u8 opcode,u8 * buf,int len)361 static int mt8173_nor_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf,
362 int len)
363 {
364 int ret;
365 struct mt8173_nor *mt8173_nor = nor->priv;
366
367 switch (opcode) {
368 case SPINOR_OP_WRSR:
369 /* We only handle 1 byte */
370 ret = mt8173_nor_wr_sr(mt8173_nor, *buf);
371 break;
372 default:
373 ret = mt8173_nor_do_tx_rx(mt8173_nor, opcode, buf, len, NULL, 0);
374 if (ret)
375 dev_warn(mt8173_nor->dev, "write reg failure!\n");
376 break;
377 }
378 return ret;
379 }
380
mtk_nor_init(struct mt8173_nor * mt8173_nor,struct device_node * flash_node)381 static int mtk_nor_init(struct mt8173_nor *mt8173_nor,
382 struct device_node *flash_node)
383 {
384 int ret;
385 struct spi_nor *nor;
386
387 /* initialize controller to accept commands */
388 writel(MTK_NOR_ENABLE_SF_CMD, mt8173_nor->base + MTK_NOR_WRPROT_REG);
389
390 nor = &mt8173_nor->nor;
391 nor->dev = mt8173_nor->dev;
392 nor->priv = mt8173_nor;
393 spi_nor_set_flash_node(nor, flash_node);
394
395 /* fill the hooks to spi nor */
396 nor->read = mt8173_nor_read;
397 nor->read_reg = mt8173_nor_read_reg;
398 nor->write = mt8173_nor_write;
399 nor->write_reg = mt8173_nor_write_reg;
400 nor->mtd.name = "mtk_nor";
401 /* initialized with NULL */
402 ret = spi_nor_scan(nor, NULL, SPI_NOR_DUAL);
403 if (ret)
404 return ret;
405
406 return mtd_device_register(&nor->mtd, NULL, 0);
407 }
408
mtk_nor_drv_probe(struct platform_device * pdev)409 static int mtk_nor_drv_probe(struct platform_device *pdev)
410 {
411 struct device_node *flash_np;
412 struct resource *res;
413 int ret;
414 struct mt8173_nor *mt8173_nor;
415
416 if (!pdev->dev.of_node) {
417 dev_err(&pdev->dev, "No DT found\n");
418 return -EINVAL;
419 }
420
421 mt8173_nor = devm_kzalloc(&pdev->dev, sizeof(*mt8173_nor), GFP_KERNEL);
422 if (!mt8173_nor)
423 return -ENOMEM;
424 platform_set_drvdata(pdev, mt8173_nor);
425
426 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
427 mt8173_nor->base = devm_ioremap_resource(&pdev->dev, res);
428 if (IS_ERR(mt8173_nor->base))
429 return PTR_ERR(mt8173_nor->base);
430
431 mt8173_nor->spi_clk = devm_clk_get(&pdev->dev, "spi");
432 if (IS_ERR(mt8173_nor->spi_clk))
433 return PTR_ERR(mt8173_nor->spi_clk);
434
435 mt8173_nor->nor_clk = devm_clk_get(&pdev->dev, "sf");
436 if (IS_ERR(mt8173_nor->nor_clk))
437 return PTR_ERR(mt8173_nor->nor_clk);
438
439 mt8173_nor->dev = &pdev->dev;
440 ret = clk_prepare_enable(mt8173_nor->spi_clk);
441 if (ret)
442 return ret;
443
444 ret = clk_prepare_enable(mt8173_nor->nor_clk);
445 if (ret) {
446 clk_disable_unprepare(mt8173_nor->spi_clk);
447 return ret;
448 }
449 /* only support one attached flash */
450 flash_np = of_get_next_available_child(pdev->dev.of_node, NULL);
451 if (!flash_np) {
452 dev_err(&pdev->dev, "no SPI flash device to configure\n");
453 ret = -ENODEV;
454 goto nor_free;
455 }
456 ret = mtk_nor_init(mt8173_nor, flash_np);
457
458 nor_free:
459 if (ret) {
460 clk_disable_unprepare(mt8173_nor->spi_clk);
461 clk_disable_unprepare(mt8173_nor->nor_clk);
462 }
463 return ret;
464 }
465
mtk_nor_drv_remove(struct platform_device * pdev)466 static int mtk_nor_drv_remove(struct platform_device *pdev)
467 {
468 struct mt8173_nor *mt8173_nor = platform_get_drvdata(pdev);
469
470 clk_disable_unprepare(mt8173_nor->spi_clk);
471 clk_disable_unprepare(mt8173_nor->nor_clk);
472 return 0;
473 }
474
475 static const struct of_device_id mtk_nor_of_ids[] = {
476 { .compatible = "mediatek,mt8173-nor"},
477 { /* sentinel */ }
478 };
479 MODULE_DEVICE_TABLE(of, mtk_nor_of_ids);
480
481 static struct platform_driver mtk_nor_driver = {
482 .probe = mtk_nor_drv_probe,
483 .remove = mtk_nor_drv_remove,
484 .driver = {
485 .name = "mtk-nor",
486 .of_match_table = mtk_nor_of_ids,
487 },
488 };
489
490 module_platform_driver(mtk_nor_driver);
491 MODULE_LICENSE("GPL v2");
492 MODULE_DESCRIPTION("MediaTek SPI NOR Flash Driver");
493