/*
* 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
*
* 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
*/
#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 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 },
{ },
};
MODULE_DEVICE_TABLE(of, imx_ocotp_dt_ids);
static int imx_ocotp_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *res;
struct ocotp_priv *priv;
struct nvmem_device *nvmem;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->dev = dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->base = devm_ioremap_resource(dev, res);
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");
