Add support for OTP controller available on LAN966X. 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 <horatiu.vultur@xxxxxxxxxxxxx>
---
drivers/nvmem/Kconfig | 8 ++
drivers/nvmem/Makefile | 2 +
drivers/nvmem/lan966x-otpc.c | 248 +++++++++++++++++++++++++++++++++++
3 files changed, 258 insertions(+)
create mode 100644 drivers/nvmem/lan966x-otpc.c
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index bab8a29c9861..7252c090a2ff 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -84,6 +84,14 @@ config NVMEM_LPC18XX_OTP
To compile this driver as a module, choose M here: the module
will be called nvmem_lpc18xx_otp.
+config NVMEM_LAN966X_OTPC
+ tristate "Microchip LAN966X OTP controller support"
+ depends on SOC_LAN966 || COMPILE_TEST
+ depends on HAS_IOMEM
+ help
+ This driver enable the OTP controller available on Microchip LAN966X
+ SoCs. It controlls the access to the OTP memory connected to it.
+
config NVMEM_MXS_OCOTP
tristate "Freescale MXS On-Chip OTP Memory Support"
depends on ARCH_MXS || COMPILE_TEST
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 399f9972d45b..c3471b4fb738 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -21,6 +21,8 @@ obj-$(CONFIG_NVMEM_LPC18XX_EEPROM) += nvmem_lpc18xx_eeprom.o
nvmem_lpc18xx_eeprom-y := lpc18xx_eeprom.o
obj-$(CONFIG_NVMEM_LPC18XX_OTP) += nvmem_lpc18xx_otp.o
nvmem_lpc18xx_otp-y := lpc18xx_otp.o
+obj-$(CONFIG_NVMEM_LAN966X_OTPC) += nvmem-lan966x-otpc.o
+nvmem-lan966x-otpc-y := lan966x-otpc.o
obj-$(CONFIG_NVMEM_MXS_OCOTP) += nvmem-mxs-ocotp.o
nvmem-mxs-ocotp-y := mxs-ocotp.o
obj-$(CONFIG_NVMEM_NINTENDO_OTP) += nvmem-nintendo-otp.o
diff --git a/drivers/nvmem/lan966x-otpc.c b/drivers/nvmem/lan966x-otpc.c
new file mode 100644
index 000000000000..d9b1721c0699
--- /dev/null
+++ b/drivers/nvmem/lan966x-otpc.c
@@ -0,0 +1,248 @@
+// 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 lan966x_otp {
+ struct device *dev;
+ void __iomem *base;
+};
+
+static inline void lan966x_writel(void __iomem *addr, u32 val)
+{
+ writel(val, addr);
+}
+
+static inline u32 lan966x_readl(void __iomem *addr)
+{
+ return readl(addr);
+}
+
+static inline void lan966x_clrbits(void __iomem *addr, u32 clear)
+{
+ writel(readl(addr) & ~clear, addr);
+}
+
+static inline void lan966x_setbits(void __iomem *addr, u32 set)
+{
+ writel(readl(addr) | set, addr);
+}
+
+static bool lan966x_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 lan966x_otp_power(struct lan966x_otp *otp, bool up)
+{
+ if (up) {
+ lan966x_clrbits(OTP_OTP_PWR_DN(otp->base),
+ OTP_OTP_PWR_DN_OTP_PWRDN_N);
+ if (lan966x_otp_wait_flag_clear(OTP_OTP_STATUS(otp->base),
+ OTP_OTP_STATUS_OTP_CPUMPEN))
+ return -ETIMEDOUT;
+ } else {
+ lan966x_setbits(OTP_OTP_PWR_DN(otp->base),
+ OTP_OTP_PWR_DN_OTP_PWRDN_N);
+ }
+
+ return 0;
+}
+
+static int lan966x_otp_execute(struct lan966x_otp *otp)
+{
+ if (lan966x_otp_wait_flag_clear(OTP_OTP_CMD_GO(otp->base),
+ OTP_OTP_CMD_GO_OTP_GO))
+ return -ETIMEDOUT;
+
+ if (lan966x_otp_wait_flag_clear(OTP_OTP_STATUS(otp->base),
+ OTP_OTP_STATUS_OTP_BUSY))
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static void lan966x_otp_set_address(struct lan966x_otp *otp, u32 offset)
+{
+ WARN_ON(offset >= OTP_MEM_SIZE);
+
+ lan966x_writel(OTP_OTP_ADDR_HI(otp->base), 0xff & (offset >> 8));
+ lan966x_writel(OTP_OTP_ADDR_LO(otp->base), 0xff & offset);
+}
+
+static int lan966x_otp_read_byte(struct lan966x_otp *otp, u32 offset, u8 *dst)
+{
+ u32 pass;
+ int rc;
+
+ lan966x_otp_set_address(otp, offset);
+ lan966x_writel(OTP_OTP_FUNC_CMD(otp->base),
+ OTP_OTP_FUNC_CMD_OTP_READ);
+ lan966x_writel(OTP_OTP_CMD_GO(otp->base),
+ OTP_OTP_CMD_GO_OTP_GO);
+ rc = lan966x_otp_execute(otp);
+ if (!rc) {
+ pass = lan966x_readl(OTP_OTP_PASS_FAIL(otp->base));
+ if (pass & OTP_OTP_PASS_FAIL_OTP_READ_PROHIBITED)
+ return -EACCES;
+ *dst = (u8) lan966x_readl(OTP_OTP_RD_DATA(otp->base));
+ }
+ return rc;
+}
+
+static int lan966x_otp_write_byte(struct lan966x_otp *otp, u32 offset, u8 data)
+{
+ u32 pass;
+ int rc;
+
+ lan966x_otp_set_address(otp, offset);
+ lan966x_writel(OTP_OTP_PRGM_MODE(otp->base),
+ OTP_OTP_PRGM_MODE_OTP_PGM_MODE_BYTE);
+ lan966x_writel(OTP_OTP_PRGM_DATA(otp->base), data);
+ lan966x_writel(OTP_OTP_FUNC_CMD(otp->base),
+ OTP_OTP_FUNC_CMD_OTP_PROGRAM);
+ lan966x_writel(OTP_OTP_CMD_GO(otp->base), OTP_OTP_CMD_GO_OTP_GO);
+
+ rc = lan966x_otp_execute(otp);
+ if (!rc) {
+ pass = lan966x_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 lan966x_otp_read(void *context, unsigned int offset,
+ void *_val, size_t bytes)
+{
+ struct lan966x_otp *otp = context;
+ u8 *val = _val;
+ uint8_t data;
+ int i, rc = 0;
+
+ lan966x_otp_power(otp, true);
+ for (i = 0; i < bytes; i++) {
+ rc = lan966x_otp_read_byte(otp, offset + i, &data);
+ if (rc < 0)
+ break;
+ *val++ = data;
+ }
+ lan966x_otp_power(otp, false);
+
+ return rc;
+}
+
+static int lan966x_otp_write(void *context, unsigned int offset,
+ void *_val, size_t bytes)
+{
+ struct lan966x_otp *otp = context;
+ u8 *val = _val;
+ u8 data, newdata;
+ int i, rc = 0;
+
+ lan966x_otp_power(otp, true);
+ for (i = 0; i < bytes; i++) {
+ /* Skip zero bytes */
+ if (val[i]) {
+ rc = lan966x_otp_read_byte(otp, offset + i, &data);
+ if (rc < 0)
+ break;
+
+ newdata = data | val[i];
+ if (newdata == data)
+ continue;
+
+ rc = lan966x_otp_write_byte(otp, offset + i,
+ newdata);
+ if (rc < 0)
+ break;
+ }
+ }
+ lan966x_otp_power(otp, false);
+
+ return rc;
+}
+
+static struct nvmem_config otp_config = {
+ .name = "lan966x-otp",
+ .stride = 1,
+ .word_size = 1,
+ .reg_read = lan966x_otp_read,
+ .reg_write = lan966x_otp_write,
+ .size = OTP_MEM_SIZE,
+};
+
+static int lan966x_otp_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct nvmem_device *nvmem;
+ struct lan966x_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 lan966x_otp_match[] = {
+ { .compatible = "microchip,lan966x-otp", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, lan966x_otp_match);
+
+static struct platform_driver lan966x_otp_driver = {
+ .probe = lan966x_otp_probe,
+ .driver = {
+ .name = "lan966x-otp",
+ .of_match_table = lan966x_otp_match,
+ },
+};
+module_platform_driver(lan966x_otp_driver);
+
+MODULE_AUTHOR("Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Lan966x OTP driver");
+MODULE_LICENSE("GPL");
--
2.33.0
