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// SPDX-License-Identifier: GPL-2.0
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#define OTP_OTP_PWR_DN(t) (t + 0x00)
#define OTP_OTP_PWR_DN_OTP_PWRDN_N BIT(0)
#define OTP_OTP_ADDR_HI(t) (t + 0x04)
#define OTP_OTP_ADDR_LO(t) (t + 0x08)
#define OTP_OTP_PRGM_DATA(t) (t + 0x10)
#define OTP_OTP_PRGM_MODE(t) (t + 0x14)
#define OTP_OTP_PRGM_MODE_OTP_PGM_MODE_BYTE BIT(0)
#define OTP_OTP_RD_DATA(t) (t + 0x18)
#define OTP_OTP_FUNC_CMD(t) (t + 0x20)
#define OTP_OTP_FUNC_CMD_OTP_PROGRAM BIT(1)
#define OTP_OTP_FUNC_CMD_OTP_READ BIT(0)
#define OTP_OTP_CMD_GO(t) (t + 0x28)
#define OTP_OTP_CMD_GO_OTP_GO BIT(0)
#define OTP_OTP_PASS_FAIL(t) (t + 0x2c)
#define OTP_OTP_PASS_FAIL_OTP_READ_PROHIBITED BIT(3)
#define OTP_OTP_PASS_FAIL_OTP_WRITE_PROHIBITED BIT(2)
#define OTP_OTP_PASS_FAIL_OTP_FAIL BIT(0)
#define OTP_OTP_STATUS(t) (t + 0x30)
#define OTP_OTP_STATUS_OTP_CPUMPEN BIT(1)
#define OTP_OTP_STATUS_OTP_BUSY BIT(0)
#define OTP_MEM_SIZE 8192
#define OTP_SLEEP_US 10
#define OTP_TIMEOUT_US 500000
struct lan9662_otp {
struct device *dev;
void __iomem *base;
};
static bool lan9662_otp_wait_flag_clear(void __iomem *reg, u32 flag)
{
u32 val;
return readl_poll_timeout(reg, val, !(val & flag),
OTP_SLEEP_US, OTP_TIMEOUT_US);
}
static int lan9662_otp_power(struct lan9662_otp *otp, bool up)
{
void __iomem *pwrdn = OTP_OTP_PWR_DN(otp->base);
if (up) {
writel(readl(pwrdn) & ~OTP_OTP_PWR_DN_OTP_PWRDN_N, pwrdn);
if (lan9662_otp_wait_flag_clear(OTP_OTP_STATUS(otp->base),
OTP_OTP_STATUS_OTP_CPUMPEN))
return -ETIMEDOUT;
} else {
writel(readl(pwrdn) | OTP_OTP_PWR_DN_OTP_PWRDN_N, pwrdn);
}
return 0;
}
static int lan9662_otp_execute(struct lan9662_otp *otp)
{
if (lan9662_otp_wait_flag_clear(OTP_OTP_CMD_GO(otp->base),
OTP_OTP_CMD_GO_OTP_GO))
return -ETIMEDOUT;
if (lan9662_otp_wait_flag_clear(OTP_OTP_STATUS(otp->base),
OTP_OTP_STATUS_OTP_BUSY))
return -ETIMEDOUT;
return 0;
}
static void lan9662_otp_set_address(struct lan9662_otp *otp, u32 offset)
{
writel(0xff & (offset >> 8), OTP_OTP_ADDR_HI(otp->base));
writel(0xff & offset, OTP_OTP_ADDR_LO(otp->base));
}
static int lan9662_otp_read_byte(struct lan9662_otp *otp, u32 offset, u8 *dst)
{
u32 pass;
int rc;
lan9662_otp_set_address(otp, offset);
writel(OTP_OTP_FUNC_CMD_OTP_READ, OTP_OTP_FUNC_CMD(otp->base));
writel(OTP_OTP_CMD_GO_OTP_GO, OTP_OTP_CMD_GO(otp->base));
rc = lan9662_otp_execute(otp);
if (!rc) {
pass = readl(OTP_OTP_PASS_FAIL(otp->base));
if (pass & OTP_OTP_PASS_FAIL_OTP_READ_PROHIBITED)
return -EACCES;
*dst = (u8) readl(OTP_OTP_RD_DATA(otp->base));
}
return rc;
}
static int lan9662_otp_write_byte(struct lan9662_otp *otp, u32 offset, u8 data)
{
u32 pass;
int rc;
lan9662_otp_set_address(otp, offset);
writel(OTP_OTP_PRGM_MODE_OTP_PGM_MODE_BYTE, OTP_OTP_PRGM_MODE(otp->base));
writel(data, OTP_OTP_PRGM_DATA(otp->base));
writel(OTP_OTP_FUNC_CMD_OTP_PROGRAM, OTP_OTP_FUNC_CMD(otp->base));
writel(OTP_OTP_CMD_GO_OTP_GO, OTP_OTP_CMD_GO(otp->base));
rc = lan9662_otp_execute(otp);
if (!rc) {
pass = readl(OTP_OTP_PASS_FAIL(otp->base));
if (pass & OTP_OTP_PASS_FAIL_OTP_WRITE_PROHIBITED)
return -EACCES;
if (pass & OTP_OTP_PASS_FAIL_OTP_FAIL)
return -EIO;
}
return rc;
}
static int lan9662_otp_read(void *context, unsigned int offset,
void *_val, size_t bytes)
{
struct lan9662_otp *otp = context;
u8 *val = _val;
uint8_t data;
int i, rc = 0;
lan9662_otp_power(otp, true);
for (i = 0; i < bytes; i++) {
rc = lan9662_otp_read_byte(otp, offset + i, &data);
if (rc < 0)
break;
*val++ = data;
}
lan9662_otp_power(otp, false);
return rc;
}
static int lan9662_otp_write(void *context, unsigned int offset,
void *_val, size_t bytes)
{
struct lan9662_otp *otp = context;
u8 *val = _val;
u8 data, newdata;
int i, rc = 0;
lan9662_otp_power(otp, true);
for (i = 0; i < bytes; i++) {
/* Skip zero bytes */
if (val[i]) {
rc = lan9662_otp_read_byte(otp, offset + i, &data);
if (rc < 0)
break;
newdata = data | val[i];
if (newdata == data)
continue;
rc = lan9662_otp_write_byte(otp, offset + i,
newdata);
if (rc < 0)
break;
}
}
lan9662_otp_power(otp, false);
return rc;
}
static struct nvmem_config otp_config = {
.name = "lan9662-otp",
.stride = 1,
.word_size = 1,
.reg_read = lan9662_otp_read,
.reg_write = lan9662_otp_write,
.size = OTP_MEM_SIZE,
};
static int lan9662_otp_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct nvmem_device *nvmem;
struct lan9662_otp *otp;
otp = devm_kzalloc(&pdev->dev, sizeof(*otp), GFP_KERNEL);
if (!otp)
return -ENOMEM;
otp->dev = dev;
otp->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(otp->base))
return PTR_ERR(otp->base);
otp_config.priv = otp;
otp_config.dev = dev;
nvmem = devm_nvmem_register(dev, &otp_config);
return PTR_ERR_OR_ZERO(nvmem);
}
static const struct of_device_id lan9662_otp_match[] = {
{ .compatible = "microchip,lan9662-otpc", },
{ },
};
MODULE_DEVICE_TABLE(of, lan9662_otp_match);
static struct platform_driver lan9662_otp_driver = {
.probe = lan9662_otp_probe,
.driver = {
.name = "lan9662-otp",
.of_match_table = lan9662_otp_match,
},
};
module_platform_driver(lan9662_otp_driver);
MODULE_AUTHOR("Horatiu Vultur <horatiu.vultur@microchip.com>");
MODULE_DESCRIPTION("lan9662 OTP driver");
MODULE_LICENSE("GPL");
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