diff options
Diffstat (limited to 'drivers/nvmem/lan9662-otpc.c')
| -rw-r--r-- | drivers/nvmem/lan9662-otpc.c | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/drivers/nvmem/lan9662-otpc.c b/drivers/nvmem/lan9662-otpc.c new file mode 100644 index 000000000..56fc19f09 --- /dev/null +++ b/drivers/nvmem/lan9662-otpc.c @@ -0,0 +1,222 @@ +// 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 int 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"); |