linux/drivers/nvmem/imx-ocotp.c
Thomas Gleixner acee2e8d66 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 460
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation http www opensource org
  licenses gpl license html http www gnu org copyleft gpl html

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 3 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081201.897982733@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:09 +02:00

504 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* i.MX6 OCOTP fusebox driver
*
* Copyright (c) 2015 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de>
*
* Based on the barebox ocotp driver,
* Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>,
* Orex Computed Radiography
*
* Write support based on the fsl_otp driver,
* Copyright (C) 2010-2013 Freescale Semiconductor, Inc
*/
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/delay.h>
#define IMX_OCOTP_OFFSET_B0W0 0x400 /* Offset from base address of the
* OTP Bank0 Word0
*/
#define IMX_OCOTP_OFFSET_PER_WORD 0x10 /* Offset between the start addr
* of two consecutive OTP words.
*/
#define IMX_OCOTP_ADDR_CTRL 0x0000
#define IMX_OCOTP_ADDR_CTRL_SET 0x0004
#define IMX_OCOTP_ADDR_CTRL_CLR 0x0008
#define IMX_OCOTP_ADDR_TIMING 0x0010
#define IMX_OCOTP_ADDR_DATA0 0x0020
#define IMX_OCOTP_ADDR_DATA1 0x0030
#define IMX_OCOTP_ADDR_DATA2 0x0040
#define IMX_OCOTP_ADDR_DATA3 0x0050
#define IMX_OCOTP_BM_CTRL_ADDR 0x0000007F
#define IMX_OCOTP_BM_CTRL_BUSY 0x00000100
#define IMX_OCOTP_BM_CTRL_ERROR 0x00000200
#define IMX_OCOTP_BM_CTRL_REL_SHADOWS 0x00000400
#define DEF_RELAX 20 /* > 16.5ns */
#define DEF_FSOURCE 1001 /* > 1000 ns */
#define DEF_STROBE_PROG 10000 /* IPG clocks */
#define IMX_OCOTP_WR_UNLOCK 0x3E770000
#define IMX_OCOTP_READ_LOCKED_VAL 0xBADABADA
static DEFINE_MUTEX(ocotp_mutex);
struct ocotp_priv {
struct device *dev;
struct clk *clk;
void __iomem *base;
const struct ocotp_params *params;
struct nvmem_config *config;
};
struct ocotp_params {
unsigned int nregs;
unsigned int bank_address_words;
void (*set_timing)(struct ocotp_priv *priv);
};
static int imx_ocotp_wait_for_busy(void __iomem *base, u32 flags)
{
int count;
u32 c, mask;
mask = IMX_OCOTP_BM_CTRL_BUSY | IMX_OCOTP_BM_CTRL_ERROR | flags;
for (count = 10000; count >= 0; count--) {
c = readl(base + IMX_OCOTP_ADDR_CTRL);
if (!(c & mask))
break;
cpu_relax();
}
if (count < 0) {
/* HW_OCOTP_CTRL[ERROR] will be set under the following
* conditions:
* - A write is performed to a shadow register during a shadow
* reload (essentially, while HW_OCOTP_CTRL[RELOAD_SHADOWS] is
* set. In addition, the contents of the shadow register shall
* not be updated.
* - A write is performed to a shadow register which has been
* locked.
* - A read is performed to from a shadow register which has
* been read locked.
* - A program is performed to a fuse word which has been locked
* - A read is performed to from a fuse word which has been read
* locked.
*/
if (c & IMX_OCOTP_BM_CTRL_ERROR)
return -EPERM;
return -ETIMEDOUT;
}
return 0;
}
static void imx_ocotp_clr_err_if_set(void __iomem *base)
{
u32 c;
c = readl(base + IMX_OCOTP_ADDR_CTRL);
if (!(c & IMX_OCOTP_BM_CTRL_ERROR))
return;
writel(IMX_OCOTP_BM_CTRL_ERROR, base + IMX_OCOTP_ADDR_CTRL_CLR);
}
static int imx_ocotp_read(void *context, unsigned int offset,
void *val, size_t bytes)
{
struct ocotp_priv *priv = context;
unsigned int count;
u32 *buf = val;
int i, ret;
u32 index;
index = offset >> 2;
count = bytes >> 2;
if (count > (priv->params->nregs - index))
count = priv->params->nregs - index;
mutex_lock(&ocotp_mutex);
ret = clk_prepare_enable(priv->clk);
if (ret < 0) {
mutex_unlock(&ocotp_mutex);
dev_err(priv->dev, "failed to prepare/enable ocotp clk\n");
return ret;
}
ret = imx_ocotp_wait_for_busy(priv->base, 0);
if (ret < 0) {
dev_err(priv->dev, "timeout during read setup\n");
goto read_end;
}
for (i = index; i < (index + count); i++) {
*buf++ = readl(priv->base + IMX_OCOTP_OFFSET_B0W0 +
i * IMX_OCOTP_OFFSET_PER_WORD);
/* 47.3.1.2
* For "read locked" registers 0xBADABADA will be returned and
* HW_OCOTP_CTRL[ERROR] will be set. It must be cleared by
* software before any new write, read or reload access can be
* issued
*/
if (*(buf - 1) == IMX_OCOTP_READ_LOCKED_VAL)
imx_ocotp_clr_err_if_set(priv->base);
}
ret = 0;
read_end:
clk_disable_unprepare(priv->clk);
mutex_unlock(&ocotp_mutex);
return ret;
}
static void imx_ocotp_set_imx6_timing(struct ocotp_priv *priv)
{
unsigned long clk_rate = 0;
unsigned long strobe_read, relax, strobe_prog;
u32 timing = 0;
/* 47.3.1.3.1
* Program HW_OCOTP_TIMING[STROBE_PROG] and HW_OCOTP_TIMING[RELAX]
* fields with timing values to match the current frequency of the
* ipg_clk. OTP writes will work at maximum bus frequencies as long
* as the HW_OCOTP_TIMING parameters are set correctly.
*/
clk_rate = clk_get_rate(priv->clk);
relax = clk_rate / (1000000000 / DEF_RELAX) - 1;
strobe_prog = clk_rate / (1000000000 / 10000) + 2 * (DEF_RELAX + 1) - 1;
strobe_read = clk_rate / (1000000000 / 40) + 2 * (DEF_RELAX + 1) - 1;
timing = strobe_prog & 0x00000FFF;
timing |= (relax << 12) & 0x0000F000;
timing |= (strobe_read << 16) & 0x003F0000;
writel(timing, priv->base + IMX_OCOTP_ADDR_TIMING);
}
static void imx_ocotp_set_imx7_timing(struct ocotp_priv *priv)
{
unsigned long clk_rate = 0;
u64 fsource, strobe_prog;
u32 timing = 0;
/* i.MX 7Solo Applications Processor Reference Manual, Rev. 0.1
* 6.4.3.3
*/
clk_rate = clk_get_rate(priv->clk);
fsource = DIV_ROUND_UP_ULL((u64)clk_rate * DEF_FSOURCE,
NSEC_PER_SEC) + 1;
strobe_prog = DIV_ROUND_CLOSEST_ULL((u64)clk_rate * DEF_STROBE_PROG,
NSEC_PER_SEC) + 1;
timing = strobe_prog & 0x00000FFF;
timing |= (fsource << 12) & 0x000FF000;
writel(timing, priv->base + IMX_OCOTP_ADDR_TIMING);
}
static int imx_ocotp_write(void *context, unsigned int offset, void *val,
size_t bytes)
{
struct ocotp_priv *priv = context;
u32 *buf = val;
int ret;
u32 ctrl;
u8 waddr;
u8 word = 0;
/* allow only writing one complete OTP word at a time */
if ((bytes != priv->config->word_size) ||
(offset % priv->config->word_size))
return -EINVAL;
mutex_lock(&ocotp_mutex);
ret = clk_prepare_enable(priv->clk);
if (ret < 0) {
mutex_unlock(&ocotp_mutex);
dev_err(priv->dev, "failed to prepare/enable ocotp clk\n");
return ret;
}
/* Setup the write timing values */
priv->params->set_timing(priv);
/* 47.3.1.3.2
* Check that HW_OCOTP_CTRL[BUSY] and HW_OCOTP_CTRL[ERROR] are clear.
* Overlapped accesses are not supported by the controller. Any pending
* write or reload must be completed before a write access can be
* requested.
*/
ret = imx_ocotp_wait_for_busy(priv->base, 0);
if (ret < 0) {
dev_err(priv->dev, "timeout during timing setup\n");
goto write_end;
}
/* 47.3.1.3.3
* Write the requested address to HW_OCOTP_CTRL[ADDR] and program the
* unlock code into HW_OCOTP_CTRL[WR_UNLOCK]. This must be programmed
* for each write access. The lock code is documented in the register
* description. Both the unlock code and address can be written in the
* same operation.
*/
if (priv->params->bank_address_words != 0) {
/*
* In banked/i.MX7 mode the OTP register bank goes into waddr
* see i.MX 7Solo Applications Processor Reference Manual, Rev.
* 0.1 section 6.4.3.1
*/
offset = offset / priv->config->word_size;
waddr = offset / priv->params->bank_address_words;
word = offset & (priv->params->bank_address_words - 1);
} else {
/*
* Non-banked i.MX6 mode.
* OTP write/read address specifies one of 128 word address
* locations
*/
waddr = offset / 4;
}
ctrl = readl(priv->base + IMX_OCOTP_ADDR_CTRL);
ctrl &= ~IMX_OCOTP_BM_CTRL_ADDR;
ctrl |= waddr & IMX_OCOTP_BM_CTRL_ADDR;
ctrl |= IMX_OCOTP_WR_UNLOCK;
writel(ctrl, priv->base + IMX_OCOTP_ADDR_CTRL);
/* 47.3.1.3.4
* Write the data to the HW_OCOTP_DATA register. This will automatically
* set HW_OCOTP_CTRL[BUSY] and clear HW_OCOTP_CTRL[WR_UNLOCK]. To
* protect programming same OTP bit twice, before program OCOTP will
* automatically read fuse value in OTP and use read value to mask
* program data. The controller will use masked program data to program
* a 32-bit word in the OTP per the address in HW_OCOTP_CTRL[ADDR]. Bit
* fields with 1's will result in that OTP bit being programmed. Bit
* fields with 0's will be ignored. At the same time that the write is
* accepted, the controller makes an internal copy of
* HW_OCOTP_CTRL[ADDR] which cannot be updated until the next write
* sequence is initiated. This copy guarantees that erroneous writes to
* HW_OCOTP_CTRL[ADDR] will not affect an active write operation. It
* should also be noted that during the programming HW_OCOTP_DATA will
* shift right (with zero fill). This shifting is required to program
* the OTP serially. During the write operation, HW_OCOTP_DATA cannot be
* modified.
* Note: on i.MX7 there are four data fields to write for banked write
* with the fuse blowing operation only taking place after data0
* has been written. This is why data0 must always be the last
* register written.
*/
if (priv->params->bank_address_words != 0) {
/* Banked/i.MX7 mode */
switch (word) {
case 0:
writel(0, priv->base + IMX_OCOTP_ADDR_DATA1);
writel(0, priv->base + IMX_OCOTP_ADDR_DATA2);
writel(0, priv->base + IMX_OCOTP_ADDR_DATA3);
writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA0);
break;
case 1:
writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA1);
writel(0, priv->base + IMX_OCOTP_ADDR_DATA2);
writel(0, priv->base + IMX_OCOTP_ADDR_DATA3);
writel(0, priv->base + IMX_OCOTP_ADDR_DATA0);
break;
case 2:
writel(0, priv->base + IMX_OCOTP_ADDR_DATA1);
writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA2);
writel(0, priv->base + IMX_OCOTP_ADDR_DATA3);
writel(0, priv->base + IMX_OCOTP_ADDR_DATA0);
break;
case 3:
writel(0, priv->base + IMX_OCOTP_ADDR_DATA1);
writel(0, priv->base + IMX_OCOTP_ADDR_DATA2);
writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA3);
writel(0, priv->base + IMX_OCOTP_ADDR_DATA0);
break;
}
} else {
/* Non-banked i.MX6 mode */
writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA0);
}
/* 47.4.1.4.5
* Once complete, the controller will clear BUSY. A write request to a
* protected or locked region will result in no OTP access and no
* setting of HW_OCOTP_CTRL[BUSY]. In addition HW_OCOTP_CTRL[ERROR] will
* be set. It must be cleared by software before any new write access
* can be issued.
*/
ret = imx_ocotp_wait_for_busy(priv->base, 0);
if (ret < 0) {
if (ret == -EPERM) {
dev_err(priv->dev, "failed write to locked region");
imx_ocotp_clr_err_if_set(priv->base);
} else {
dev_err(priv->dev, "timeout during data write\n");
}
goto write_end;
}
/* 47.3.1.4
* Write Postamble: Due to internal electrical characteristics of the
* OTP during writes, all OTP operations following a write must be
* separated by 2 us after the clearing of HW_OCOTP_CTRL_BUSY following
* the write.
*/
udelay(2);
/* reload all shadow registers */
writel(IMX_OCOTP_BM_CTRL_REL_SHADOWS,
priv->base + IMX_OCOTP_ADDR_CTRL_SET);
ret = imx_ocotp_wait_for_busy(priv->base,
IMX_OCOTP_BM_CTRL_REL_SHADOWS);
if (ret < 0) {
dev_err(priv->dev, "timeout during shadow register reload\n");
goto write_end;
}
write_end:
clk_disable_unprepare(priv->clk);
mutex_unlock(&ocotp_mutex);
if (ret < 0)
return ret;
return bytes;
}
static struct nvmem_config imx_ocotp_nvmem_config = {
.name = "imx-ocotp",
.read_only = false,
.word_size = 4,
.stride = 4,
.reg_read = imx_ocotp_read,
.reg_write = imx_ocotp_write,
};
static const struct ocotp_params imx6q_params = {
.nregs = 128,
.bank_address_words = 0,
.set_timing = imx_ocotp_set_imx6_timing,
};
static const struct ocotp_params imx6sl_params = {
.nregs = 64,
.bank_address_words = 0,
.set_timing = imx_ocotp_set_imx6_timing,
};
static const struct ocotp_params imx6sll_params = {
.nregs = 128,
.bank_address_words = 0,
.set_timing = imx_ocotp_set_imx6_timing,
};
static const struct ocotp_params imx6sx_params = {
.nregs = 128,
.bank_address_words = 0,
.set_timing = imx_ocotp_set_imx6_timing,
};
static const struct ocotp_params imx6ul_params = {
.nregs = 128,
.bank_address_words = 0,
.set_timing = imx_ocotp_set_imx6_timing,
};
static const struct ocotp_params imx6ull_params = {
.nregs = 64,
.bank_address_words = 0,
.set_timing = imx_ocotp_set_imx6_timing,
};
static const struct ocotp_params imx7d_params = {
.nregs = 64,
.bank_address_words = 4,
.set_timing = imx_ocotp_set_imx7_timing,
};
static const struct ocotp_params imx7ulp_params = {
.nregs = 256,
.bank_address_words = 0,
};
static const struct ocotp_params imx8mq_params = {
.nregs = 256,
.bank_address_words = 4,
.set_timing = imx_ocotp_set_imx7_timing,
};
static const struct of_device_id imx_ocotp_dt_ids[] = {
{ .compatible = "fsl,imx6q-ocotp", .data = &imx6q_params },
{ .compatible = "fsl,imx6sl-ocotp", .data = &imx6sl_params },
{ .compatible = "fsl,imx6sx-ocotp", .data = &imx6sx_params },
{ .compatible = "fsl,imx6ul-ocotp", .data = &imx6ul_params },
{ .compatible = "fsl,imx6ull-ocotp", .data = &imx6ull_params },
{ .compatible = "fsl,imx7d-ocotp", .data = &imx7d_params },
{ .compatible = "fsl,imx6sll-ocotp", .data = &imx6sll_params },
{ .compatible = "fsl,imx7ulp-ocotp", .data = &imx7ulp_params },
{ .compatible = "fsl,imx8mq-ocotp", .data = &imx8mq_params },
{ },
};
MODULE_DEVICE_TABLE(of, imx_ocotp_dt_ids);
static int imx_ocotp_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ocotp_priv *priv;
struct nvmem_device *nvmem;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->dev = dev;
priv->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
priv->clk = devm_clk_get(dev, NULL);
if (IS_ERR(priv->clk))
return PTR_ERR(priv->clk);
priv->params = of_device_get_match_data(&pdev->dev);
imx_ocotp_nvmem_config.size = 4 * priv->params->nregs;
imx_ocotp_nvmem_config.dev = dev;
imx_ocotp_nvmem_config.priv = priv;
priv->config = &imx_ocotp_nvmem_config;
nvmem = devm_nvmem_register(dev, &imx_ocotp_nvmem_config);
return PTR_ERR_OR_ZERO(nvmem);
}
static struct platform_driver imx_ocotp_driver = {
.probe = imx_ocotp_probe,
.driver = {
.name = "imx_ocotp",
.of_match_table = imx_ocotp_dt_ids,
},
};
module_platform_driver(imx_ocotp_driver);
MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
MODULE_DESCRIPTION("i.MX6/i.MX7 OCOTP fuse box driver");
MODULE_LICENSE("GPL v2");