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1 | /* | |
2 | * i.MX6 OCOTP fusebox driver | |
3 | * | |
4 | * Copyright (c) 2015 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de> | |
5 | * | |
6 | * Based on the barebox ocotp driver, | |
7 | * Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>, | |
8 | * Orex Computed Radiography | |
9 | * | |
10 | * Write support based on the fsl_otp driver, | |
11 | * Copyright (C) 2010-2013 Freescale Semiconductor, Inc | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or modify | |
14 | * it under the terms of the GNU General Public License version 2 | |
15 | * as published by the Free Software Foundation. | |
16 | * | |
17 | * http://www.opensource.org/licenses/gpl-license.html | |
18 | * http://www.gnu.org/copyleft/gpl.html | |
19 | */ | |
20 | ||
21 | #include <linux/clk.h> | |
22 | #include <linux/device.h> | |
23 | #include <linux/io.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/nvmem-provider.h> | |
26 | #include <linux/of.h> | |
27 | #include <linux/of_device.h> | |
28 | #include <linux/platform_device.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/delay.h> | |
31 | ||
32 | #define IMX_OCOTP_OFFSET_B0W0 0x400 /* Offset from base address of the | |
33 | * OTP Bank0 Word0 | |
34 | */ | |
35 | #define IMX_OCOTP_OFFSET_PER_WORD 0x10 /* Offset between the start addr | |
36 | * of two consecutive OTP words. | |
37 | */ | |
38 | ||
39 | #define IMX_OCOTP_ADDR_CTRL 0x0000 | |
40 | #define IMX_OCOTP_ADDR_CTRL_SET 0x0004 | |
41 | #define IMX_OCOTP_ADDR_CTRL_CLR 0x0008 | |
42 | #define IMX_OCOTP_ADDR_TIMING 0x0010 | |
43 | #define IMX_OCOTP_ADDR_DATA0 0x0020 | |
44 | #define IMX_OCOTP_ADDR_DATA1 0x0030 | |
45 | #define IMX_OCOTP_ADDR_DATA2 0x0040 | |
46 | #define IMX_OCOTP_ADDR_DATA3 0x0050 | |
47 | ||
48 | #define IMX_OCOTP_BM_CTRL_ADDR 0x0000007F | |
49 | #define IMX_OCOTP_BM_CTRL_BUSY 0x00000100 | |
50 | #define IMX_OCOTP_BM_CTRL_ERROR 0x00000200 | |
51 | #define IMX_OCOTP_BM_CTRL_REL_SHADOWS 0x00000400 | |
52 | ||
53 | #define DEF_RELAX 20 /* > 16.5ns */ | |
54 | #define DEF_FSOURCE 1001 /* > 1000 ns */ | |
55 | #define DEF_STROBE_PROG 10000 /* IPG clocks */ | |
56 | #define IMX_OCOTP_WR_UNLOCK 0x3E770000 | |
57 | #define IMX_OCOTP_READ_LOCKED_VAL 0xBADABADA | |
58 | ||
59 | static DEFINE_MUTEX(ocotp_mutex); | |
60 | ||
61 | struct ocotp_priv { | |
62 | struct device *dev; | |
63 | struct clk *clk; | |
64 | void __iomem *base; | |
65 | const struct ocotp_params *params; | |
66 | struct nvmem_config *config; | |
67 | }; | |
68 | ||
69 | struct ocotp_params { | |
70 | unsigned int nregs; | |
71 | unsigned int bank_address_words; | |
72 | void (*set_timing)(struct ocotp_priv *priv); | |
73 | }; | |
74 | ||
75 | static int imx_ocotp_wait_for_busy(void __iomem *base, u32 flags) | |
76 | { | |
77 | int count; | |
78 | u32 c, mask; | |
79 | ||
80 | mask = IMX_OCOTP_BM_CTRL_BUSY | IMX_OCOTP_BM_CTRL_ERROR | flags; | |
81 | ||
82 | for (count = 10000; count >= 0; count--) { | |
83 | c = readl(base + IMX_OCOTP_ADDR_CTRL); | |
84 | if (!(c & mask)) | |
85 | break; | |
86 | cpu_relax(); | |
87 | } | |
88 | ||
89 | if (count < 0) { | |
90 | /* HW_OCOTP_CTRL[ERROR] will be set under the following | |
91 | * conditions: | |
92 | * - A write is performed to a shadow register during a shadow | |
93 | * reload (essentially, while HW_OCOTP_CTRL[RELOAD_SHADOWS] is | |
94 | * set. In addition, the contents of the shadow register shall | |
95 | * not be updated. | |
96 | * - A write is performed to a shadow register which has been | |
97 | * locked. | |
98 | * - A read is performed to from a shadow register which has | |
99 | * been read locked. | |
100 | * - A program is performed to a fuse word which has been locked | |
101 | * - A read is performed to from a fuse word which has been read | |
102 | * locked. | |
103 | */ | |
104 | if (c & IMX_OCOTP_BM_CTRL_ERROR) | |
105 | return -EPERM; | |
106 | return -ETIMEDOUT; | |
107 | } | |
108 | ||
109 | return 0; | |
110 | } | |
111 | ||
112 | static void imx_ocotp_clr_err_if_set(void __iomem *base) | |
113 | { | |
114 | u32 c; | |
115 | ||
116 | c = readl(base + IMX_OCOTP_ADDR_CTRL); | |
117 | if (!(c & IMX_OCOTP_BM_CTRL_ERROR)) | |
118 | return; | |
119 | ||
120 | writel(IMX_OCOTP_BM_CTRL_ERROR, base + IMX_OCOTP_ADDR_CTRL_CLR); | |
121 | } | |
122 | ||
123 | static int imx_ocotp_read(void *context, unsigned int offset, | |
124 | void *val, size_t bytes) | |
125 | { | |
126 | struct ocotp_priv *priv = context; | |
127 | unsigned int count; | |
128 | u32 *buf = val; | |
129 | int i, ret; | |
130 | u32 index; | |
131 | ||
132 | index = offset >> 2; | |
133 | count = bytes >> 2; | |
134 | ||
135 | if (count > (priv->params->nregs - index)) | |
136 | count = priv->params->nregs - index; | |
137 | ||
138 | mutex_lock(&ocotp_mutex); | |
139 | ||
140 | ret = clk_prepare_enable(priv->clk); | |
141 | if (ret < 0) { | |
142 | mutex_unlock(&ocotp_mutex); | |
143 | dev_err(priv->dev, "failed to prepare/enable ocotp clk\n"); | |
144 | return ret; | |
145 | } | |
146 | ||
147 | ret = imx_ocotp_wait_for_busy(priv->base, 0); | |
148 | if (ret < 0) { | |
149 | dev_err(priv->dev, "timeout during read setup\n"); | |
150 | goto read_end; | |
151 | } | |
152 | ||
153 | for (i = index; i < (index + count); i++) { | |
154 | *buf++ = readl(priv->base + IMX_OCOTP_OFFSET_B0W0 + | |
155 | i * IMX_OCOTP_OFFSET_PER_WORD); | |
156 | ||
157 | /* 47.3.1.2 | |
158 | * For "read locked" registers 0xBADABADA will be returned and | |
159 | * HW_OCOTP_CTRL[ERROR] will be set. It must be cleared by | |
160 | * software before any new write, read or reload access can be | |
161 | * issued | |
162 | */ | |
163 | if (*(buf - 1) == IMX_OCOTP_READ_LOCKED_VAL) | |
164 | imx_ocotp_clr_err_if_set(priv->base); | |
165 | } | |
166 | ret = 0; | |
167 | ||
168 | read_end: | |
169 | clk_disable_unprepare(priv->clk); | |
170 | mutex_unlock(&ocotp_mutex); | |
171 | return ret; | |
172 | } | |
173 | ||
174 | static void imx_ocotp_set_imx6_timing(struct ocotp_priv *priv) | |
175 | { | |
176 | unsigned long clk_rate = 0; | |
177 | unsigned long strobe_read, relax, strobe_prog; | |
178 | u32 timing = 0; | |
179 | ||
180 | /* 47.3.1.3.1 | |
181 | * Program HW_OCOTP_TIMING[STROBE_PROG] and HW_OCOTP_TIMING[RELAX] | |
182 | * fields with timing values to match the current frequency of the | |
183 | * ipg_clk. OTP writes will work at maximum bus frequencies as long | |
184 | * as the HW_OCOTP_TIMING parameters are set correctly. | |
185 | */ | |
186 | clk_rate = clk_get_rate(priv->clk); | |
187 | ||
188 | relax = clk_rate / (1000000000 / DEF_RELAX) - 1; | |
189 | strobe_prog = clk_rate / (1000000000 / 10000) + 2 * (DEF_RELAX + 1) - 1; | |
190 | strobe_read = clk_rate / (1000000000 / 40) + 2 * (DEF_RELAX + 1) - 1; | |
191 | ||
192 | timing = strobe_prog & 0x00000FFF; | |
193 | timing |= (relax << 12) & 0x0000F000; | |
194 | timing |= (strobe_read << 16) & 0x003F0000; | |
195 | ||
196 | writel(timing, priv->base + IMX_OCOTP_ADDR_TIMING); | |
197 | } | |
198 | ||
199 | static void imx_ocotp_set_imx7_timing(struct ocotp_priv *priv) | |
200 | { | |
201 | unsigned long clk_rate = 0; | |
202 | u64 fsource, strobe_prog; | |
203 | u32 timing = 0; | |
204 | ||
205 | /* i.MX 7Solo Applications Processor Reference Manual, Rev. 0.1 | |
206 | * 6.4.3.3 | |
207 | */ | |
208 | clk_rate = clk_get_rate(priv->clk); | |
209 | fsource = DIV_ROUND_UP_ULL((u64)clk_rate * DEF_FSOURCE, | |
210 | NSEC_PER_SEC) + 1; | |
211 | strobe_prog = DIV_ROUND_CLOSEST_ULL((u64)clk_rate * DEF_STROBE_PROG, | |
212 | NSEC_PER_SEC) + 1; | |
213 | ||
214 | timing = strobe_prog & 0x00000FFF; | |
215 | timing |= (fsource << 12) & 0x000FF000; | |
216 | ||
217 | writel(timing, priv->base + IMX_OCOTP_ADDR_TIMING); | |
218 | } | |
219 | ||
220 | static int imx_ocotp_write(void *context, unsigned int offset, void *val, | |
221 | size_t bytes) | |
222 | { | |
223 | struct ocotp_priv *priv = context; | |
224 | u32 *buf = val; | |
225 | int ret; | |
226 | ||
227 | u32 ctrl; | |
228 | u8 waddr; | |
229 | u8 word = 0; | |
230 | ||
231 | /* allow only writing one complete OTP word at a time */ | |
232 | if ((bytes != priv->config->word_size) || | |
233 | (offset % priv->config->word_size)) | |
234 | return -EINVAL; | |
235 | ||
236 | mutex_lock(&ocotp_mutex); | |
237 | ||
238 | ret = clk_prepare_enable(priv->clk); | |
239 | if (ret < 0) { | |
240 | mutex_unlock(&ocotp_mutex); | |
241 | dev_err(priv->dev, "failed to prepare/enable ocotp clk\n"); | |
242 | return ret; | |
243 | } | |
244 | ||
245 | /* Setup the write timing values */ | |
246 | priv->params->set_timing(priv); | |
247 | ||
248 | /* 47.3.1.3.2 | |
249 | * Check that HW_OCOTP_CTRL[BUSY] and HW_OCOTP_CTRL[ERROR] are clear. | |
250 | * Overlapped accesses are not supported by the controller. Any pending | |
251 | * write or reload must be completed before a write access can be | |
252 | * requested. | |
253 | */ | |
254 | ret = imx_ocotp_wait_for_busy(priv->base, 0); | |
255 | if (ret < 0) { | |
256 | dev_err(priv->dev, "timeout during timing setup\n"); | |
257 | goto write_end; | |
258 | } | |
259 | ||
260 | /* 47.3.1.3.3 | |
261 | * Write the requested address to HW_OCOTP_CTRL[ADDR] and program the | |
262 | * unlock code into HW_OCOTP_CTRL[WR_UNLOCK]. This must be programmed | |
263 | * for each write access. The lock code is documented in the register | |
264 | * description. Both the unlock code and address can be written in the | |
265 | * same operation. | |
266 | */ | |
267 | if (priv->params->bank_address_words != 0) { | |
268 | /* | |
269 | * In banked/i.MX7 mode the OTP register bank goes into waddr | |
270 | * see i.MX 7Solo Applications Processor Reference Manual, Rev. | |
271 | * 0.1 section 6.4.3.1 | |
272 | */ | |
273 | offset = offset / priv->config->word_size; | |
274 | waddr = offset / priv->params->bank_address_words; | |
275 | word = offset & (priv->params->bank_address_words - 1); | |
276 | } else { | |
277 | /* | |
278 | * Non-banked i.MX6 mode. | |
279 | * OTP write/read address specifies one of 128 word address | |
280 | * locations | |
281 | */ | |
282 | waddr = offset / 4; | |
283 | } | |
284 | ||
285 | ctrl = readl(priv->base + IMX_OCOTP_ADDR_CTRL); | |
286 | ctrl &= ~IMX_OCOTP_BM_CTRL_ADDR; | |
287 | ctrl |= waddr & IMX_OCOTP_BM_CTRL_ADDR; | |
288 | ctrl |= IMX_OCOTP_WR_UNLOCK; | |
289 | ||
290 | writel(ctrl, priv->base + IMX_OCOTP_ADDR_CTRL); | |
291 | ||
292 | /* 47.3.1.3.4 | |
293 | * Write the data to the HW_OCOTP_DATA register. This will automatically | |
294 | * set HW_OCOTP_CTRL[BUSY] and clear HW_OCOTP_CTRL[WR_UNLOCK]. To | |
295 | * protect programming same OTP bit twice, before program OCOTP will | |
296 | * automatically read fuse value in OTP and use read value to mask | |
297 | * program data. The controller will use masked program data to program | |
298 | * a 32-bit word in the OTP per the address in HW_OCOTP_CTRL[ADDR]. Bit | |
299 | * fields with 1's will result in that OTP bit being programmed. Bit | |
300 | * fields with 0's will be ignored. At the same time that the write is | |
301 | * accepted, the controller makes an internal copy of | |
302 | * HW_OCOTP_CTRL[ADDR] which cannot be updated until the next write | |
303 | * sequence is initiated. This copy guarantees that erroneous writes to | |
304 | * HW_OCOTP_CTRL[ADDR] will not affect an active write operation. It | |
305 | * should also be noted that during the programming HW_OCOTP_DATA will | |
306 | * shift right (with zero fill). This shifting is required to program | |
307 | * the OTP serially. During the write operation, HW_OCOTP_DATA cannot be | |
308 | * modified. | |
309 | * Note: on i.MX7 there are four data fields to write for banked write | |
310 | * with the fuse blowing operation only taking place after data0 | |
311 | * has been written. This is why data0 must always be the last | |
312 | * register written. | |
313 | */ | |
314 | if (priv->params->bank_address_words != 0) { | |
315 | /* Banked/i.MX7 mode */ | |
316 | switch (word) { | |
317 | case 0: | |
318 | writel(0, priv->base + IMX_OCOTP_ADDR_DATA1); | |
319 | writel(0, priv->base + IMX_OCOTP_ADDR_DATA2); | |
320 | writel(0, priv->base + IMX_OCOTP_ADDR_DATA3); | |
321 | writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA0); | |
322 | break; | |
323 | case 1: | |
324 | writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA1); | |
325 | writel(0, priv->base + IMX_OCOTP_ADDR_DATA2); | |
326 | writel(0, priv->base + IMX_OCOTP_ADDR_DATA3); | |
327 | writel(0, priv->base + IMX_OCOTP_ADDR_DATA0); | |
328 | break; | |
329 | case 2: | |
330 | writel(0, priv->base + IMX_OCOTP_ADDR_DATA1); | |
331 | writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA2); | |
332 | writel(0, priv->base + IMX_OCOTP_ADDR_DATA3); | |
333 | writel(0, priv->base + IMX_OCOTP_ADDR_DATA0); | |
334 | break; | |
335 | case 3: | |
336 | writel(0, priv->base + IMX_OCOTP_ADDR_DATA1); | |
337 | writel(0, priv->base + IMX_OCOTP_ADDR_DATA2); | |
338 | writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA3); | |
339 | writel(0, priv->base + IMX_OCOTP_ADDR_DATA0); | |
340 | break; | |
341 | } | |
342 | } else { | |
343 | /* Non-banked i.MX6 mode */ | |
344 | writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA0); | |
345 | } | |
346 | ||
347 | /* 47.4.1.4.5 | |
348 | * Once complete, the controller will clear BUSY. A write request to a | |
349 | * protected or locked region will result in no OTP access and no | |
350 | * setting of HW_OCOTP_CTRL[BUSY]. In addition HW_OCOTP_CTRL[ERROR] will | |
351 | * be set. It must be cleared by software before any new write access | |
352 | * can be issued. | |
353 | */ | |
354 | ret = imx_ocotp_wait_for_busy(priv->base, 0); | |
355 | if (ret < 0) { | |
356 | if (ret == -EPERM) { | |
357 | dev_err(priv->dev, "failed write to locked region"); | |
358 | imx_ocotp_clr_err_if_set(priv->base); | |
359 | } else { | |
360 | dev_err(priv->dev, "timeout during data write\n"); | |
361 | } | |
362 | goto write_end; | |
363 | } | |
364 | ||
365 | /* 47.3.1.4 | |
366 | * Write Postamble: Due to internal electrical characteristics of the | |
367 | * OTP during writes, all OTP operations following a write must be | |
368 | * separated by 2 us after the clearing of HW_OCOTP_CTRL_BUSY following | |
369 | * the write. | |
370 | */ | |
371 | udelay(2); | |
372 | ||
373 | /* reload all shadow registers */ | |
374 | writel(IMX_OCOTP_BM_CTRL_REL_SHADOWS, | |
375 | priv->base + IMX_OCOTP_ADDR_CTRL_SET); | |
376 | ret = imx_ocotp_wait_for_busy(priv->base, | |
377 | IMX_OCOTP_BM_CTRL_REL_SHADOWS); | |
378 | if (ret < 0) { | |
379 | dev_err(priv->dev, "timeout during shadow register reload\n"); | |
380 | goto write_end; | |
381 | } | |
382 | ||
383 | write_end: | |
384 | clk_disable_unprepare(priv->clk); | |
385 | mutex_unlock(&ocotp_mutex); | |
386 | if (ret < 0) | |
387 | return ret; | |
388 | return bytes; | |
389 | } | |
390 | ||
391 | static struct nvmem_config imx_ocotp_nvmem_config = { | |
392 | .name = "imx-ocotp", | |
393 | .read_only = false, | |
394 | .word_size = 4, | |
395 | .stride = 4, | |
396 | .reg_read = imx_ocotp_read, | |
397 | .reg_write = imx_ocotp_write, | |
398 | }; | |
399 | ||
400 | static const struct ocotp_params imx6q_params = { | |
401 | .nregs = 128, | |
402 | .bank_address_words = 0, | |
403 | .set_timing = imx_ocotp_set_imx6_timing, | |
404 | }; | |
405 | ||
406 | static const struct ocotp_params imx6sl_params = { | |
407 | .nregs = 64, | |
408 | .bank_address_words = 0, | |
409 | .set_timing = imx_ocotp_set_imx6_timing, | |
410 | }; | |
411 | ||
412 | static const struct ocotp_params imx6sll_params = { | |
413 | .nregs = 128, | |
414 | .bank_address_words = 0, | |
415 | .set_timing = imx_ocotp_set_imx6_timing, | |
416 | }; | |
417 | ||
418 | static const struct ocotp_params imx6sx_params = { | |
419 | .nregs = 128, | |
420 | .bank_address_words = 0, | |
421 | .set_timing = imx_ocotp_set_imx6_timing, | |
422 | }; | |
423 | ||
424 | static const struct ocotp_params imx6ul_params = { | |
425 | .nregs = 128, | |
426 | .bank_address_words = 0, | |
427 | .set_timing = imx_ocotp_set_imx6_timing, | |
428 | }; | |
429 | ||
430 | static const struct ocotp_params imx7d_params = { | |
431 | .nregs = 64, | |
432 | .bank_address_words = 4, | |
433 | .set_timing = imx_ocotp_set_imx7_timing, | |
434 | }; | |
435 | ||
436 | static const struct of_device_id imx_ocotp_dt_ids[] = { | |
437 | { .compatible = "fsl,imx6q-ocotp", .data = &imx6q_params }, | |
438 | { .compatible = "fsl,imx6sl-ocotp", .data = &imx6sl_params }, | |
439 | { .compatible = "fsl,imx6sx-ocotp", .data = &imx6sx_params }, | |
440 | { .compatible = "fsl,imx6ul-ocotp", .data = &imx6ul_params }, | |
441 | { .compatible = "fsl,imx7d-ocotp", .data = &imx7d_params }, | |
442 | { .compatible = "fsl,imx6sll-ocotp", .data = &imx6sll_params }, | |
443 | { }, | |
444 | }; | |
445 | MODULE_DEVICE_TABLE(of, imx_ocotp_dt_ids); | |
446 | ||
447 | static int imx_ocotp_probe(struct platform_device *pdev) | |
448 | { | |
449 | struct device *dev = &pdev->dev; | |
450 | struct resource *res; | |
451 | struct ocotp_priv *priv; | |
452 | struct nvmem_device *nvmem; | |
453 | ||
454 | priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); | |
455 | if (!priv) | |
456 | return -ENOMEM; | |
457 | ||
458 | priv->dev = dev; | |
459 | ||
460 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
461 | priv->base = devm_ioremap_resource(dev, res); | |
462 | if (IS_ERR(priv->base)) | |
463 | return PTR_ERR(priv->base); | |
464 | ||
465 | priv->clk = devm_clk_get(dev, NULL); | |
466 | if (IS_ERR(priv->clk)) | |
467 | return PTR_ERR(priv->clk); | |
468 | ||
469 | priv->params = of_device_get_match_data(&pdev->dev); | |
470 | imx_ocotp_nvmem_config.size = 4 * priv->params->nregs; | |
471 | imx_ocotp_nvmem_config.dev = dev; | |
472 | imx_ocotp_nvmem_config.priv = priv; | |
473 | priv->config = &imx_ocotp_nvmem_config; | |
474 | nvmem = devm_nvmem_register(dev, &imx_ocotp_nvmem_config); | |
475 | ||
476 | ||
477 | return PTR_ERR_OR_ZERO(nvmem); | |
478 | } | |
479 | ||
480 | static struct platform_driver imx_ocotp_driver = { | |
481 | .probe = imx_ocotp_probe, | |
482 | .driver = { | |
483 | .name = "imx_ocotp", | |
484 | .of_match_table = imx_ocotp_dt_ids, | |
485 | }, | |
486 | }; | |
487 | module_platform_driver(imx_ocotp_driver); | |
488 | ||
489 | MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>"); | |
490 | MODULE_DESCRIPTION("i.MX6/i.MX7 OCOTP fuse box driver"); | |
491 | MODULE_LICENSE("GPL v2"); |