1 // SPDX-License-Identifier: GPL-2.0-only
3 * i.MX6 OCOTP fusebox driver
5 * Copyright (c) 2015 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de>
9 * Based on the barebox ocotp driver,
10 * Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>,
11 * Orex Computed Radiography
13 * Write support based on the fsl_otp driver,
14 * Copyright (C) 2010-2013 Freescale Semiconductor, Inc
17 #include <linux/clk.h>
18 #include <linux/device.h>
20 #include <linux/module.h>
21 #include <linux/nvmem-provider.h>
23 #include <linux/platform_device.h>
24 #include <linux/slab.h>
25 #include <linux/delay.h>
27 #define IMX_OCOTP_OFFSET_B0W0 0x400 /* Offset from base address of the
30 #define IMX_OCOTP_OFFSET_PER_WORD 0x10 /* Offset between the start addr
31 * of two consecutive OTP words.
34 #define IMX_OCOTP_ADDR_CTRL 0x0000
35 #define IMX_OCOTP_ADDR_CTRL_SET 0x0004
36 #define IMX_OCOTP_ADDR_CTRL_CLR 0x0008
37 #define IMX_OCOTP_ADDR_TIMING 0x0010
38 #define IMX_OCOTP_ADDR_DATA0 0x0020
39 #define IMX_OCOTP_ADDR_DATA1 0x0030
40 #define IMX_OCOTP_ADDR_DATA2 0x0040
41 #define IMX_OCOTP_ADDR_DATA3 0x0050
43 #define IMX_OCOTP_BM_CTRL_ADDR 0x000000FF
44 #define IMX_OCOTP_BM_CTRL_BUSY 0x00000100
45 #define IMX_OCOTP_BM_CTRL_ERROR 0x00000200
46 #define IMX_OCOTP_BM_CTRL_REL_SHADOWS 0x00000400
48 #define IMX_OCOTP_BM_CTRL_ADDR_8MP 0x000001FF
49 #define IMX_OCOTP_BM_CTRL_BUSY_8MP 0x00000200
50 #define IMX_OCOTP_BM_CTRL_ERROR_8MP 0x00000400
51 #define IMX_OCOTP_BM_CTRL_REL_SHADOWS_8MP 0x00000800
53 #define IMX_OCOTP_BM_CTRL_DEFAULT \
55 .bm_addr = IMX_OCOTP_BM_CTRL_ADDR, \
56 .bm_busy = IMX_OCOTP_BM_CTRL_BUSY, \
57 .bm_error = IMX_OCOTP_BM_CTRL_ERROR, \
58 .bm_rel_shadows = IMX_OCOTP_BM_CTRL_REL_SHADOWS,\
61 #define IMX_OCOTP_BM_CTRL_8MP \
63 .bm_addr = IMX_OCOTP_BM_CTRL_ADDR_8MP, \
64 .bm_busy = IMX_OCOTP_BM_CTRL_BUSY_8MP, \
65 .bm_error = IMX_OCOTP_BM_CTRL_ERROR_8MP, \
66 .bm_rel_shadows = IMX_OCOTP_BM_CTRL_REL_SHADOWS_8MP,\
69 #define TIMING_STROBE_PROG_US 10 /* Min time to blow a fuse */
70 #define TIMING_STROBE_READ_NS 37 /* Min time before read */
71 #define TIMING_RELAX_NS 17
72 #define DEF_FSOURCE 1001 /* > 1000 ns */
73 #define DEF_STROBE_PROG 10000 /* IPG clocks */
74 #define IMX_OCOTP_WR_UNLOCK 0x3E770000
75 #define IMX_OCOTP_READ_LOCKED_VAL 0xBADABADA
77 static DEFINE_MUTEX(ocotp_mutex
);
83 const struct ocotp_params
*params
;
84 struct nvmem_config
*config
;
87 struct ocotp_ctrl_reg
{
96 unsigned int bank_address_words
;
97 void (*set_timing
)(struct ocotp_priv
*priv
);
98 struct ocotp_ctrl_reg ctrl
;
101 static int imx_ocotp_wait_for_busy(struct ocotp_priv
*priv
, u32 flags
)
105 u32 bm_ctrl_busy
, bm_ctrl_error
;
106 void __iomem
*base
= priv
->base
;
108 bm_ctrl_busy
= priv
->params
->ctrl
.bm_busy
;
109 bm_ctrl_error
= priv
->params
->ctrl
.bm_error
;
111 mask
= bm_ctrl_busy
| bm_ctrl_error
| flags
;
113 for (count
= 10000; count
>= 0; count
--) {
114 c
= readl(base
+ IMX_OCOTP_ADDR_CTRL
);
121 /* HW_OCOTP_CTRL[ERROR] will be set under the following
123 * - A write is performed to a shadow register during a shadow
124 * reload (essentially, while HW_OCOTP_CTRL[RELOAD_SHADOWS] is
125 * set. In addition, the contents of the shadow register shall
127 * - A write is performed to a shadow register which has been
129 * - A read is performed to from a shadow register which has
131 * - A program is performed to a fuse word which has been locked
132 * - A read is performed to from a fuse word which has been read
135 if (c
& bm_ctrl_error
)
143 static void imx_ocotp_clr_err_if_set(struct ocotp_priv
*priv
)
145 u32 c
, bm_ctrl_error
;
146 void __iomem
*base
= priv
->base
;
148 bm_ctrl_error
= priv
->params
->ctrl
.bm_error
;
150 c
= readl(base
+ IMX_OCOTP_ADDR_CTRL
);
151 if (!(c
& bm_ctrl_error
))
154 writel(bm_ctrl_error
, base
+ IMX_OCOTP_ADDR_CTRL_CLR
);
157 static int imx_ocotp_read(void *context
, unsigned int offset
,
158 void *val
, size_t bytes
)
160 struct ocotp_priv
*priv
= context
;
164 u32 index
, num_bytes
;
167 num_bytes
= round_up((offset
% 4) + bytes
, 4);
168 count
= num_bytes
>> 2;
170 if (count
> (priv
->params
->nregs
- index
))
171 count
= priv
->params
->nregs
- index
;
173 p
= kzalloc(num_bytes
, GFP_KERNEL
);
177 mutex_lock(&ocotp_mutex
);
181 ret
= clk_prepare_enable(priv
->clk
);
183 mutex_unlock(&ocotp_mutex
);
184 dev_err(priv
->dev
, "failed to prepare/enable ocotp clk\n");
189 ret
= imx_ocotp_wait_for_busy(priv
, 0);
191 dev_err(priv
->dev
, "timeout during read setup\n");
195 for (i
= index
; i
< (index
+ count
); i
++) {
196 *(u32
*)buf
= readl(priv
->base
+ IMX_OCOTP_OFFSET_B0W0
+
197 i
* IMX_OCOTP_OFFSET_PER_WORD
);
200 * For "read locked" registers 0xBADABADA will be returned and
201 * HW_OCOTP_CTRL[ERROR] will be set. It must be cleared by
202 * software before any new write, read or reload access can be
205 if (*((u32
*)buf
) == IMX_OCOTP_READ_LOCKED_VAL
)
206 imx_ocotp_clr_err_if_set(priv
);
212 memcpy(val
, &p
[index
], bytes
);
215 clk_disable_unprepare(priv
->clk
);
216 mutex_unlock(&ocotp_mutex
);
223 static int imx_ocotp_cell_pp(void *context
, const char *id
, int index
,
224 unsigned int offset
, void *data
, size_t bytes
)
229 /* Deal with some post processing of nvmem cell data */
230 if (id
&& !strcmp(id
, "mac-address"))
231 for (i
= 0; i
< bytes
/ 2; i
++)
232 swap(buf
[i
], buf
[bytes
- i
- 1]);
237 static void imx_ocotp_set_imx6_timing(struct ocotp_priv
*priv
)
239 unsigned long clk_rate
;
240 unsigned long strobe_read
, relax
, strobe_prog
;
244 * Program HW_OCOTP_TIMING[STROBE_PROG] and HW_OCOTP_TIMING[RELAX]
245 * fields with timing values to match the current frequency of the
246 * ipg_clk. OTP writes will work at maximum bus frequencies as long
247 * as the HW_OCOTP_TIMING parameters are set correctly.
249 * Note: there are minimum timings required to ensure an OTP fuse burns
250 * correctly that are independent of the ipg_clk. Those values are not
251 * formally documented anywhere however, working from the minimum
252 * timings given in u-boot we can say:
254 * - Minimum STROBE_PROG time is 10 microseconds. Intuitively 10
255 * microseconds feels about right as representative of a minimum time
256 * to physically burn out a fuse.
258 * - Minimum STROBE_READ i.e. the time to wait post OTP fuse burn before
259 * performing another read is 37 nanoseconds
261 * - Minimum RELAX timing is 17 nanoseconds. This final RELAX minimum
262 * timing is not entirely clear the documentation says "This
263 * count value specifies the time to add to all default timing
264 * parameters other than the Tpgm and Trd. It is given in number
265 * of ipg_clk periods." where Tpgm and Trd refer to STROBE_PROG
266 * and STROBE_READ respectively. What the other timing parameters
267 * are though, is not specified. Experience shows a zero RELAX
268 * value will mess up a re-load of the shadow registers post OTP
271 clk_rate
= clk_get_rate(priv
->clk
);
273 relax
= DIV_ROUND_UP(clk_rate
* TIMING_RELAX_NS
, 1000000000) - 1;
274 strobe_read
= DIV_ROUND_UP(clk_rate
* TIMING_STROBE_READ_NS
,
276 strobe_read
+= 2 * (relax
+ 1) - 1;
277 strobe_prog
= DIV_ROUND_CLOSEST(clk_rate
* TIMING_STROBE_PROG_US
,
279 strobe_prog
+= 2 * (relax
+ 1) - 1;
281 timing
= readl(priv
->base
+ IMX_OCOTP_ADDR_TIMING
) & 0x0FC00000;
282 timing
|= strobe_prog
& 0x00000FFF;
283 timing
|= (relax
<< 12) & 0x0000F000;
284 timing
|= (strobe_read
<< 16) & 0x003F0000;
286 writel(timing
, priv
->base
+ IMX_OCOTP_ADDR_TIMING
);
289 static void imx_ocotp_set_imx7_timing(struct ocotp_priv
*priv
)
291 unsigned long clk_rate
;
292 u64 fsource
, strobe_prog
;
295 /* i.MX 7Solo Applications Processor Reference Manual, Rev. 0.1
298 clk_rate
= clk_get_rate(priv
->clk
);
299 fsource
= DIV_ROUND_UP_ULL((u64
)clk_rate
* DEF_FSOURCE
,
301 strobe_prog
= DIV_ROUND_CLOSEST_ULL((u64
)clk_rate
* DEF_STROBE_PROG
,
304 timing
= strobe_prog
& 0x00000FFF;
305 timing
|= (fsource
<< 12) & 0x000FF000;
307 writel(timing
, priv
->base
+ IMX_OCOTP_ADDR_TIMING
);
310 static int imx_ocotp_write(void *context
, unsigned int offset
, void *val
,
313 struct ocotp_priv
*priv
= context
;
321 /* allow only writing one complete OTP word at a time */
322 if ((bytes
!= priv
->config
->word_size
) ||
323 (offset
% priv
->config
->word_size
))
326 mutex_lock(&ocotp_mutex
);
328 ret
= clk_prepare_enable(priv
->clk
);
330 mutex_unlock(&ocotp_mutex
);
331 dev_err(priv
->dev
, "failed to prepare/enable ocotp clk\n");
335 /* Setup the write timing values */
336 priv
->params
->set_timing(priv
);
339 * Check that HW_OCOTP_CTRL[BUSY] and HW_OCOTP_CTRL[ERROR] are clear.
340 * Overlapped accesses are not supported by the controller. Any pending
341 * write or reload must be completed before a write access can be
344 ret
= imx_ocotp_wait_for_busy(priv
, 0);
346 dev_err(priv
->dev
, "timeout during timing setup\n");
351 * Write the requested address to HW_OCOTP_CTRL[ADDR] and program the
352 * unlock code into HW_OCOTP_CTRL[WR_UNLOCK]. This must be programmed
353 * for each write access. The lock code is documented in the register
354 * description. Both the unlock code and address can be written in the
357 if (priv
->params
->bank_address_words
!= 0) {
359 * In banked/i.MX7 mode the OTP register bank goes into waddr
360 * see i.MX 7Solo Applications Processor Reference Manual, Rev.
361 * 0.1 section 6.4.3.1
363 offset
= offset
/ priv
->config
->word_size
;
364 waddr
= offset
/ priv
->params
->bank_address_words
;
365 word
= offset
& (priv
->params
->bank_address_words
- 1);
368 * Non-banked i.MX6 mode.
369 * OTP write/read address specifies one of 128 word address
375 ctrl
= readl(priv
->base
+ IMX_OCOTP_ADDR_CTRL
);
376 ctrl
&= ~priv
->params
->ctrl
.bm_addr
;
377 ctrl
|= waddr
& priv
->params
->ctrl
.bm_addr
;
378 ctrl
|= IMX_OCOTP_WR_UNLOCK
;
380 writel(ctrl
, priv
->base
+ IMX_OCOTP_ADDR_CTRL
);
383 * Write the data to the HW_OCOTP_DATA register. This will automatically
384 * set HW_OCOTP_CTRL[BUSY] and clear HW_OCOTP_CTRL[WR_UNLOCK]. To
385 * protect programming same OTP bit twice, before program OCOTP will
386 * automatically read fuse value in OTP and use read value to mask
387 * program data. The controller will use masked program data to program
388 * a 32-bit word in the OTP per the address in HW_OCOTP_CTRL[ADDR]. Bit
389 * fields with 1's will result in that OTP bit being programmed. Bit
390 * fields with 0's will be ignored. At the same time that the write is
391 * accepted, the controller makes an internal copy of
392 * HW_OCOTP_CTRL[ADDR] which cannot be updated until the next write
393 * sequence is initiated. This copy guarantees that erroneous writes to
394 * HW_OCOTP_CTRL[ADDR] will not affect an active write operation. It
395 * should also be noted that during the programming HW_OCOTP_DATA will
396 * shift right (with zero fill). This shifting is required to program
397 * the OTP serially. During the write operation, HW_OCOTP_DATA cannot be
399 * Note: on i.MX7 there are four data fields to write for banked write
400 * with the fuse blowing operation only taking place after data0
401 * has been written. This is why data0 must always be the last
404 if (priv
->params
->bank_address_words
!= 0) {
405 /* Banked/i.MX7 mode */
408 writel(0, priv
->base
+ IMX_OCOTP_ADDR_DATA1
);
409 writel(0, priv
->base
+ IMX_OCOTP_ADDR_DATA2
);
410 writel(0, priv
->base
+ IMX_OCOTP_ADDR_DATA3
);
411 writel(*buf
, priv
->base
+ IMX_OCOTP_ADDR_DATA0
);
414 writel(*buf
, priv
->base
+ IMX_OCOTP_ADDR_DATA1
);
415 writel(0, priv
->base
+ IMX_OCOTP_ADDR_DATA2
);
416 writel(0, priv
->base
+ IMX_OCOTP_ADDR_DATA3
);
417 writel(0, priv
->base
+ IMX_OCOTP_ADDR_DATA0
);
420 writel(0, priv
->base
+ IMX_OCOTP_ADDR_DATA1
);
421 writel(*buf
, priv
->base
+ IMX_OCOTP_ADDR_DATA2
);
422 writel(0, priv
->base
+ IMX_OCOTP_ADDR_DATA3
);
423 writel(0, priv
->base
+ IMX_OCOTP_ADDR_DATA0
);
426 writel(0, priv
->base
+ IMX_OCOTP_ADDR_DATA1
);
427 writel(0, priv
->base
+ IMX_OCOTP_ADDR_DATA2
);
428 writel(*buf
, priv
->base
+ IMX_OCOTP_ADDR_DATA3
);
429 writel(0, priv
->base
+ IMX_OCOTP_ADDR_DATA0
);
433 /* Non-banked i.MX6 mode */
434 writel(*buf
, priv
->base
+ IMX_OCOTP_ADDR_DATA0
);
438 * Once complete, the controller will clear BUSY. A write request to a
439 * protected or locked region will result in no OTP access and no
440 * setting of HW_OCOTP_CTRL[BUSY]. In addition HW_OCOTP_CTRL[ERROR] will
441 * be set. It must be cleared by software before any new write access
444 ret
= imx_ocotp_wait_for_busy(priv
, 0);
447 dev_err(priv
->dev
, "failed write to locked region");
448 imx_ocotp_clr_err_if_set(priv
);
450 dev_err(priv
->dev
, "timeout during data write\n");
456 * Write Postamble: Due to internal electrical characteristics of the
457 * OTP during writes, all OTP operations following a write must be
458 * separated by 2 us after the clearing of HW_OCOTP_CTRL_BUSY following
463 /* reload all shadow registers */
464 writel(priv
->params
->ctrl
.bm_rel_shadows
,
465 priv
->base
+ IMX_OCOTP_ADDR_CTRL_SET
);
466 ret
= imx_ocotp_wait_for_busy(priv
,
467 priv
->params
->ctrl
.bm_rel_shadows
);
469 dev_err(priv
->dev
, "timeout during shadow register reload\n");
472 clk_disable_unprepare(priv
->clk
);
473 mutex_unlock(&ocotp_mutex
);
474 return ret
< 0 ? ret
: bytes
;
477 static struct nvmem_config imx_ocotp_nvmem_config
= {
482 .reg_read
= imx_ocotp_read
,
483 .reg_write
= imx_ocotp_write
,
486 static const struct ocotp_params imx6q_params
= {
488 .bank_address_words
= 0,
489 .set_timing
= imx_ocotp_set_imx6_timing
,
490 .ctrl
= IMX_OCOTP_BM_CTRL_DEFAULT
,
493 static const struct ocotp_params imx6sl_params
= {
495 .bank_address_words
= 0,
496 .set_timing
= imx_ocotp_set_imx6_timing
,
497 .ctrl
= IMX_OCOTP_BM_CTRL_DEFAULT
,
500 static const struct ocotp_params imx6sll_params
= {
502 .bank_address_words
= 0,
503 .set_timing
= imx_ocotp_set_imx6_timing
,
504 .ctrl
= IMX_OCOTP_BM_CTRL_DEFAULT
,
507 static const struct ocotp_params imx6sx_params
= {
509 .bank_address_words
= 0,
510 .set_timing
= imx_ocotp_set_imx6_timing
,
511 .ctrl
= IMX_OCOTP_BM_CTRL_DEFAULT
,
514 static const struct ocotp_params imx6ul_params
= {
516 .bank_address_words
= 0,
517 .set_timing
= imx_ocotp_set_imx6_timing
,
518 .ctrl
= IMX_OCOTP_BM_CTRL_DEFAULT
,
521 static const struct ocotp_params imx6ull_params
= {
523 .bank_address_words
= 0,
524 .set_timing
= imx_ocotp_set_imx6_timing
,
525 .ctrl
= IMX_OCOTP_BM_CTRL_DEFAULT
,
528 static const struct ocotp_params imx7d_params
= {
530 .bank_address_words
= 4,
531 .set_timing
= imx_ocotp_set_imx7_timing
,
532 .ctrl
= IMX_OCOTP_BM_CTRL_DEFAULT
,
535 static const struct ocotp_params imx7ulp_params
= {
537 .bank_address_words
= 0,
538 .ctrl
= IMX_OCOTP_BM_CTRL_DEFAULT
,
541 static const struct ocotp_params imx8mq_params
= {
543 .bank_address_words
= 0,
544 .set_timing
= imx_ocotp_set_imx6_timing
,
545 .ctrl
= IMX_OCOTP_BM_CTRL_DEFAULT
,
548 static const struct ocotp_params imx8mm_params
= {
550 .bank_address_words
= 0,
551 .set_timing
= imx_ocotp_set_imx6_timing
,
552 .ctrl
= IMX_OCOTP_BM_CTRL_DEFAULT
,
555 static const struct ocotp_params imx8mn_params
= {
557 .bank_address_words
= 0,
558 .set_timing
= imx_ocotp_set_imx6_timing
,
559 .ctrl
= IMX_OCOTP_BM_CTRL_DEFAULT
,
562 static const struct ocotp_params imx8mp_params
= {
564 .bank_address_words
= 0,
565 .set_timing
= imx_ocotp_set_imx6_timing
,
566 .ctrl
= IMX_OCOTP_BM_CTRL_8MP
,
569 static const struct of_device_id imx_ocotp_dt_ids
[] = {
570 { .compatible
= "fsl,imx6q-ocotp", .data
= &imx6q_params
},
571 { .compatible
= "fsl,imx6sl-ocotp", .data
= &imx6sl_params
},
572 { .compatible
= "fsl,imx6sx-ocotp", .data
= &imx6sx_params
},
573 { .compatible
= "fsl,imx6ul-ocotp", .data
= &imx6ul_params
},
574 { .compatible
= "fsl,imx6ull-ocotp", .data
= &imx6ull_params
},
575 { .compatible
= "fsl,imx7d-ocotp", .data
= &imx7d_params
},
576 { .compatible
= "fsl,imx6sll-ocotp", .data
= &imx6sll_params
},
577 { .compatible
= "fsl,imx7ulp-ocotp", .data
= &imx7ulp_params
},
578 { .compatible
= "fsl,imx8mq-ocotp", .data
= &imx8mq_params
},
579 { .compatible
= "fsl,imx8mm-ocotp", .data
= &imx8mm_params
},
580 { .compatible
= "fsl,imx8mn-ocotp", .data
= &imx8mn_params
},
581 { .compatible
= "fsl,imx8mp-ocotp", .data
= &imx8mp_params
},
584 MODULE_DEVICE_TABLE(of
, imx_ocotp_dt_ids
);
586 static void imx_ocotp_fixup_dt_cell_info(struct nvmem_device
*nvmem
,
587 struct nvmem_cell_info
*cell
)
589 cell
->read_post_process
= imx_ocotp_cell_pp
;
592 static int imx_ocotp_probe(struct platform_device
*pdev
)
594 struct device
*dev
= &pdev
->dev
;
595 struct ocotp_priv
*priv
;
596 struct nvmem_device
*nvmem
;
598 priv
= devm_kzalloc(dev
, sizeof(*priv
), GFP_KERNEL
);
604 priv
->base
= devm_platform_ioremap_resource(pdev
, 0);
605 if (IS_ERR(priv
->base
))
606 return PTR_ERR(priv
->base
);
608 priv
->clk
= devm_clk_get(dev
, NULL
);
609 if (IS_ERR(priv
->clk
))
610 return PTR_ERR(priv
->clk
);
612 priv
->params
= of_device_get_match_data(&pdev
->dev
);
613 imx_ocotp_nvmem_config
.add_legacy_fixed_of_cells
= true;
614 imx_ocotp_nvmem_config
.size
= 4 * priv
->params
->nregs
;
615 imx_ocotp_nvmem_config
.dev
= dev
;
616 imx_ocotp_nvmem_config
.priv
= priv
;
617 imx_ocotp_nvmem_config
.fixup_dt_cell_info
= &imx_ocotp_fixup_dt_cell_info
;
619 priv
->config
= &imx_ocotp_nvmem_config
;
621 clk_prepare_enable(priv
->clk
);
622 imx_ocotp_clr_err_if_set(priv
);
623 clk_disable_unprepare(priv
->clk
);
625 nvmem
= devm_nvmem_register(dev
, &imx_ocotp_nvmem_config
);
627 return PTR_ERR_OR_ZERO(nvmem
);
630 static struct platform_driver imx_ocotp_driver
= {
631 .probe
= imx_ocotp_probe
,
634 .of_match_table
= imx_ocotp_dt_ids
,
637 module_platform_driver(imx_ocotp_driver
);
639 MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
640 MODULE_DESCRIPTION("i.MX6/i.MX7 OCOTP fuse box driver");
641 MODULE_LICENSE("GPL v2");