// SPDX-License-Identifier: GPL-2.0-only
/*
* i . MX6 OCOTP fusebox driver
*
* Copyright ( c ) 2015 Pengutronix , Philipp Zabel < p . zabel @ pengutronix . de >
*
* Copyright 2019 NXP
*
* 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/platform_device.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/if_ether.h> /* ETH_ALEN */
#define IMX_OCOTP_OFFSET_B0W0 0 x400 /* Offset from base address of the
* OTP Bank0 Word0
*/
#define IMX_OCOTP_OFFSET_PER_WORD 0 x10 /* Offset between the start addr
* of two consecutive OTP words .
*/
#define IMX_OCOTP_ADDR_CTRL 0 x0000
#define IMX_OCOTP_ADDR_CTRL_SET 0 x0004
#define IMX_OCOTP_ADDR_CTRL_CLR 0 x0008
#define IMX_OCOTP_ADDR_TIMING 0 x0010
#define IMX_OCOTP_ADDR_DATA0 0 x0020
#define IMX_OCOTP_ADDR_DATA1 0 x0030
#define IMX_OCOTP_ADDR_DATA2 0 x0040
#define IMX_OCOTP_ADDR_DATA3 0 x0050
#define IMX_OCOTP_BM_CTRL_ADDR 0 x000000FF
#define IMX_OCOTP_BM_CTRL_BUSY 0 x00000100
#define IMX_OCOTP_BM_CTRL_ERROR 0 x00000200
#define IMX_OCOTP_BM_CTRL_REL_SHADOWS 0 x00000400
#define IMX_OCOTP_BM_CTRL_ADDR_8MP 0 x000001FF
#define IMX_OCOTP_BM_CTRL_BUSY_8MP 0 x00000200
#define IMX_OCOTP_BM_CTRL_ERROR_8MP 0 x00000400
#define IMX_OCOTP_BM_CTRL_REL_SHADOWS_8MP 0 x00000800
#define IMX_OCOTP_BM_CTRL_DEFAULT \
{ \
.bm_addr = IMX_OCOTP_BM_CTRL_ADDR, \
.bm_busy = IMX_OCOTP_BM_CTRL_BUSY, \
.bm_error = IMX_OCOTP_BM_CTRL_ERROR, \
.bm_rel_shadows = IMX_OCOTP_BM_CTRL_REL_SHADOWS,\
}
#define IMX_OCOTP_BM_CTRL_8MP \
{ \
.bm_addr = IMX_OCOTP_BM_CTRL_ADDR_8MP, \
.bm_busy = IMX_OCOTP_BM_CTRL_BUSY_8MP, \
.bm_error = IMX_OCOTP_BM_CTRL_ERROR_8MP, \
.bm_rel_shadows = IMX_OCOTP_BM_CTRL_REL_SHADOWS_8MP,\
}
#define TIMING_STROBE_PROG_US 10 /* Min time to blow a fuse */
#define TIMING_STROBE_READ_NS 37 /* Min time before read */
#define TIMING_RELAX_NS 17
#define DEF_FSOURCE 1001 /* > 1000 ns */
#define DEF_STROBE_PROG 10000 /* IPG clocks */
#define IMX_OCOTP_WR_UNLOCK 0 x3E770000
#define IMX_OCOTP_READ_LOCKED_VAL 0 xBADABADA
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_ctrl_reg {
u32 bm_addr;
u32 bm_busy;
u32 bm_error;
u32 bm_rel_shadows;
};
struct ocotp_params {
unsigned int nregs;
unsigned int bank_address_words;
void (*set_timing)(struct ocotp_priv *priv);
struct ocotp_ctrl_reg ctrl;
};
static int imx_ocotp_wait_for_busy(struct ocotp_priv *priv, u32 flags)
{
int count;
u32 c, mask;
u32 bm_ctrl_busy, bm_ctrl_error;
void __iomem *base = priv->base;
bm_ctrl_busy = priv->params->ctrl.bm_busy;
bm_ctrl_error = priv->params->ctrl.bm_error;
mask = bm_ctrl_busy | 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 & bm_ctrl_error)
return -EPERM;
return -ETIMEDOUT;
}
return 0 ;
}
static void imx_ocotp_clr_err_if_set(struct ocotp_priv *priv)
{
u32 c, bm_ctrl_error;
void __iomem *base = priv->base;
bm_ctrl_error = priv->params->ctrl.bm_error;
c = readl(base + IMX_OCOTP_ADDR_CTRL);
if (!(c & bm_ctrl_error))
return ;
writel(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;
u8 *buf, *p;
int i, ret;
u32 index, num_bytes;
index = offset >> 2 ;
num_bytes = round_up((offset % 4 ) + bytes, 4 );
count = num_bytes >> 2 ;
if (count > (priv->params->nregs - index))
count = priv->params->nregs - index;
p = kzalloc(num_bytes, GFP_KERNEL);
if (!p)
return -ENOMEM;
mutex_lock(&ocotp_mutex);
buf = p;
ret = clk_prepare_enable(priv->clk);
if (ret < 0 ) {
mutex_unlock(&ocotp_mutex);
dev_err(priv->dev, "failed to prepare/enable ocotp clk\n" );
kfree(p);
return ret;
}
ret = imx_ocotp_wait_for_busy(priv, 0 );
if (ret < 0 ) {
dev_err(priv->dev, "timeout during read setup\n" );
goto read_end;
}
for (i = index; i < (index + count); i++) {
*(u32 *)buf = readl(priv->base + IMX_OCOTP_OFFSET_B0W0 +
i * IMX_OCOTP_OFFSET_PER_WORD);
/* 47.3.1.2
* For " read locked " registers 0 xBADABADA 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 (*((u32 *)buf) == IMX_OCOTP_READ_LOCKED_VAL)
imx_ocotp_clr_err_if_set(priv);
buf += 4 ;
}
index = offset % 4 ;
memcpy(val, &p[index], bytes);
read_end:
clk_disable_unprepare(priv->clk);
mutex_unlock(&ocotp_mutex);
kfree(p);
return ret;
}
static int imx_ocotp_cell_pp(void *context, const char *id, int index,
unsigned int offset, void *data, size_t bytes)
{
u8 *buf = data;
int i;
/* Deal with some post processing of nvmem cell data */
if (id && !strcmp(id, "mac-address" )) {
bytes = min(bytes, ETH_ALEN);
for (i = 0 ; i < bytes / 2 ; i++)
swap(buf[i], buf[bytes - i - 1 ]);
}
return 0 ;
}
static void imx_ocotp_set_imx6_timing(struct ocotp_priv *priv)
{
unsigned long clk_rate;
unsigned long strobe_read, relax, strobe_prog;
u32 timing;
/* 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 .
*
* Note : there are minimum timings required to ensure an OTP fuse burns
* correctly that are independent of the ipg_clk . Those values are not
* formally documented anywhere however , working from the minimum
* timings given in u - boot we can say :
*
* - Minimum STROBE_PROG time is 10 microseconds . Intuitively 10
* microseconds feels about right as representative of a minimum time
* to physically burn out a fuse .
*
* - Minimum STROBE_READ i . e . the time to wait post OTP fuse burn before
* performing another read is 37 nanoseconds
*
* - Minimum RELAX timing is 17 nanoseconds . This final RELAX minimum
* timing is not entirely clear the documentation says " This
* count value specifies the time to add to all default timing
* parameters other than the Tpgm and Trd . It is given in number
* of ipg_clk periods . " where Tpgm and Trd refer to STROBE_PROG
* and STROBE_READ respectively . What the other timing parameters
* are though , is not specified . Experience shows a zero RELAX
* value will mess up a re - load of the shadow registers post OTP
* burn .
*/
clk_rate = clk_get_rate(priv->clk);
relax = DIV_ROUND_UP(clk_rate * TIMING_RELAX_NS, 1000000000 ) - 1 ;
strobe_read = DIV_ROUND_UP(clk_rate * TIMING_STROBE_READ_NS,
1000000000 );
strobe_read += 2 * (relax + 1 ) - 1 ;
strobe_prog = DIV_ROUND_CLOSEST(clk_rate * TIMING_STROBE_PROG_US,
1000000 );
strobe_prog += 2 * (relax + 1 ) - 1 ;
timing = readl(priv->base + IMX_OCOTP_ADDR_TIMING) & 0 x0FC00000;
timing |= strobe_prog & 0 x00000FFF;
timing |= (relax << 12 ) & 0 x0000F000;
timing |= (strobe_read << 16 ) & 0 x003F0000;
writel(timing, priv->base + IMX_OCOTP_ADDR_TIMING);
}
static void imx_ocotp_set_imx7_timing(struct ocotp_priv *priv)
{
unsigned long clk_rate;
u64 fsource, strobe_prog;
u32 timing;
/* 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 & 0 x00000FFF;
timing |= (fsource << 12 ) & 0 x000FF000;
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, 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 7 Solo 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 &= ~priv->params->ctrl.bm_addr;
ctrl |= waddr & priv->params->ctrl.bm_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, 0 );
if (ret < 0 ) {
if (ret == -EPERM) {
dev_err(priv->dev, "failed write to locked region" );
imx_ocotp_clr_err_if_set(priv);
} 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(priv->params->ctrl.bm_rel_shadows,
priv->base + IMX_OCOTP_ADDR_CTRL_SET);
ret = imx_ocotp_wait_for_busy(priv,
priv->params->ctrl.bm_rel_shadows);
if (ret < 0 )
dev_err(priv->dev, "timeout during shadow register reload\n" );
write_end:
clk_disable_unprepare(priv->clk);
mutex_unlock(&ocotp_mutex);
return ret < 0 ? ret : bytes;
}
static struct nvmem_config imx_ocotp_nvmem_config = {
.name = "imx-ocotp" ,
.read_only = false ,
.word_size = 4 ,
.stride = 1 ,
.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,
.ctrl = IMX_OCOTP_BM_CTRL_DEFAULT,
};
static const struct ocotp_params imx6sl_params = {
.nregs = 64 ,
.bank_address_words = 0 ,
.set_timing = imx_ocotp_set_imx6_timing,
.ctrl = IMX_OCOTP_BM_CTRL_DEFAULT,
};
static const struct ocotp_params imx6sll_params = {
.nregs = 80 ,
.bank_address_words = 0 ,
.set_timing = imx_ocotp_set_imx6_timing,
.ctrl = IMX_OCOTP_BM_CTRL_DEFAULT,
};
static const struct ocotp_params imx6sx_params = {
.nregs = 128 ,
.bank_address_words = 0 ,
.set_timing = imx_ocotp_set_imx6_timing,
.ctrl = IMX_OCOTP_BM_CTRL_DEFAULT,
};
static const struct ocotp_params imx6ul_params = {
.nregs = 144 ,
.bank_address_words = 0 ,
.set_timing = imx_ocotp_set_imx6_timing,
.ctrl = IMX_OCOTP_BM_CTRL_DEFAULT,
};
static const struct ocotp_params imx6ull_params = {
.nregs = 80 ,
.bank_address_words = 0 ,
.set_timing = imx_ocotp_set_imx6_timing,
.ctrl = IMX_OCOTP_BM_CTRL_DEFAULT,
};
static const struct ocotp_params imx7d_params = {
.nregs = 64 ,
.bank_address_words = 4 ,
.set_timing = imx_ocotp_set_imx7_timing,
.ctrl = IMX_OCOTP_BM_CTRL_DEFAULT,
};
static const struct ocotp_params imx7ulp_params = {
.nregs = 256 ,
.bank_address_words = 0 ,
.ctrl = IMX_OCOTP_BM_CTRL_DEFAULT,
};
static const struct ocotp_params imx8mq_params = {
.nregs = 256 ,
.bank_address_words = 0 ,
.set_timing = imx_ocotp_set_imx6_timing,
.ctrl = IMX_OCOTP_BM_CTRL_DEFAULT,
};
static const struct ocotp_params imx8mm_params = {
.nregs = 256 ,
.bank_address_words = 0 ,
.set_timing = imx_ocotp_set_imx6_timing,
.ctrl = IMX_OCOTP_BM_CTRL_DEFAULT,
};
static const struct ocotp_params imx8mn_params = {
.nregs = 256 ,
.bank_address_words = 0 ,
.set_timing = imx_ocotp_set_imx6_timing,
.ctrl = IMX_OCOTP_BM_CTRL_DEFAULT,
};
static const struct ocotp_params imx8mp_params = {
.nregs = 384 ,
.bank_address_words = 0 ,
.set_timing = imx_ocotp_set_imx6_timing,
.ctrl = IMX_OCOTP_BM_CTRL_8MP,
};
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 },
{ .compatible = "fsl,imx8mm-ocotp" , .data = &imx8mm_params },
{ .compatible = "fsl,imx8mn-ocotp" , .data = &imx8mn_params },
{ .compatible = "fsl,imx8mp-ocotp" , .data = &imx8mp_params },
{ },
};
MODULE_DEVICE_TABLE(of, imx_ocotp_dt_ids);
static void imx_ocotp_fixup_dt_cell_info(struct nvmem_device *nvmem,
struct nvmem_cell_info *cell)
{
cell->read_post_process = imx_ocotp_cell_pp;
}
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.add_legacy_fixed_of_cells = true ;
imx_ocotp_nvmem_config.size = 4 * priv->params->nregs;
imx_ocotp_nvmem_config.dev = dev;
imx_ocotp_nvmem_config.priv = priv;
imx_ocotp_nvmem_config.fixup_dt_cell_info = &imx_ocotp_fixup_dt_cell_info;
priv->config = &imx_ocotp_nvmem_config;
clk_prepare_enable(priv->clk);
imx_ocotp_clr_err_if_set(priv);
clk_disable_unprepare(priv->clk);
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" );
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