From 9e8f208ad5229ddda97cd4a83ecf89c735d99592 Mon Sep 17 00:00:00 2001 From: Horatiu Vultur Date: Fri, 16 Sep 2022 13:20:59 +0100 Subject: [PATCH] nvmem: lan9662-otp: add support Add support for OTP controller available on LAN9662. The OTPC controls the access to a non-volatile memory. The size of the memory is 8KB. The OTPC can access the memory based on an offset. Implement both the read and the write functionality. Signed-off-by: Horatiu Vultur Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20220916122100.170016-13-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/Kconfig | 8 ++ drivers/nvmem/Makefile | 2 + drivers/nvmem/lan9662-otpc.c | 222 +++++++++++++++++++++++++++++++++++ 3 files changed, 232 insertions(+) create mode 100644 drivers/nvmem/lan9662-otpc.c --- a/drivers/nvmem/Kconfig +++ b/drivers/nvmem/Kconfig @@ -98,6 +98,14 @@ config NVMEM_JZ4780_EFUSE To compile this driver as a module, choose M here: the module will be called nvmem_jz4780_efuse. +config NVMEM_LAN9662_OTPC + tristate "Microchip LAN9662 OTP controller support" + depends on SOC_LAN966 || COMPILE_TEST + depends on HAS_IOMEM + help + This driver enables the OTP controller available on Microchip LAN9662 + SoCs. It controls the access to the OTP memory connected to it. + config NVMEM_LAYERSCAPE_SFP tristate "Layerscape SFP (Security Fuse Processor) support" depends on ARCH_LAYERSCAPE || COMPILE_TEST --- a/drivers/nvmem/Makefile +++ b/drivers/nvmem/Makefile @@ -21,6 +21,8 @@ obj-$(CONFIG_NVMEM_IMX_OCOTP_SCU) += nvm nvmem-imx-ocotp-scu-y := imx-ocotp-scu.o obj-$(CONFIG_NVMEM_JZ4780_EFUSE) += nvmem_jz4780_efuse.o nvmem_jz4780_efuse-y := jz4780-efuse.o +obj-$(CONFIG_NVMEM_LAN9662_OTPC) += nvmem-lan9662-otpc.o +nvmem-lan9662-otpc-y := lan9662-otpc.o obj-$(CONFIG_NVMEM_LAYERSCAPE_SFP) += nvmem-layerscape-sfp.o nvmem-layerscape-sfp-y := layerscape-sfp.o obj-$(CONFIG_NVMEM_LPC18XX_EEPROM) += nvmem_lpc18xx_eeprom.o --- /dev/null +++ b/drivers/nvmem/lan9662-otpc.c @@ -0,0 +1,222 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include +#include + +#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-otp", }, + { }, +}; +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 "); +MODULE_DESCRIPTION("lan9662 OTP driver"); +MODULE_LICENSE("GPL");