On 25/08/2022 21:40, Horatiu Vultur wrote:
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 <horatiu.vultur@xxxxxxxxxxxxx>
---
drivers/nvmem/Kconfig | 8 ++
drivers/nvmem/Makefile | 2 +
drivers/nvmem/lan9662-otpc.c | 249 +++++++++++++++++++++++++++++++++++
3 files changed, 259 insertions(+)
create mode 100644 drivers/nvmem/lan9662-otpc.c
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 967d0084800e..c9929ec35a39 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_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 controlls the access to the OTP memory connected to it.
+
s/controlls/controls/
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 00e136a0a123..e1baface2c53 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-$(CONFIG_NVMEM_LAN9662_OTPC) += nvmem-lan9662-otpc.o
+nvmem-lan9662-otpc-y := lan9662-otpc.o
obj-$(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/lan9662-otpc.c b/drivers/nvmem/lan9662-otpc.c
new file mode 100644
index 000000000000..302a5bae04dc
--- /dev/null
+++ b/drivers/nvmem/lan9662-otpc.c
@@ -0,0 +1,249 @@
+// 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 inline void lan9662_writel(void __iomem *addr, u32 val)
+{
+ writel(val, addr);
+}
+
+static inline u32 lan9662_readl(void __iomem *addr)
+{
+ return readl(addr);
+}
+
Why these boiler plate functions?
+static inline void lan9662_clrbits(void __iomem *addr, u32 clear)
+{
+ writel(readl(addr) & ~clear, addr);
+}
+
+static inline void lan9662_setbits(void __iomem *addr, u32 set)
+{
+ writel(readl(addr) | set, addr);
+}
These two functions are called just once and I see no point in having a
wrapper function for this, instead you could use them directly or use
./include/linux/bitfield.h helper macros.
+
+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)
+{
+ if (up) {
+ lan9662_clrbits(OTP_OTP_PWR_DN(otp->base),
+ OTP_OTP_PWR_DN_OTP_PWRDN_N);
+ if (lan9662_otp_wait_flag_clear(OTP_OTP_STATUS(otp->base),
+ OTP_OTP_STATUS_OTP_CPUMPEN))
+ return -ETIMEDOUT;
+ } else {
+ lan9662_setbits(OTP_OTP_PWR_DN(otp->base),
+ OTP_OTP_PWR_DN_OTP_PWRDN_N);
+ }
+
+ 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)
+{
+ WARN_ON(offset >= OTP_MEM_SIZE);
+
would we ever hit this condition? looks like unecessary check.
+ lan9662_writel(OTP_OTP_ADDR_HI(otp->base), 0xff & (offset >> 8));
+ lan9662_writel(OTP_OTP_ADDR_LO(otp->base), 0xff & offset);
+}
+
+static int lan9662_otp_read_byte(struct lan9662_otp *otp, u32 offset, u8 *dst)
+{
+ u32 pass;
+ int rc;
+
+ lan9662_otp_set_address(otp, offset);
+ lan9662_writel(OTP_OTP_FUNC_CMD(otp->base),
+ OTP_OTP_FUNC_CMD_OTP_READ);
+ lan9662_writel(OTP_OTP_CMD_GO(otp->base),
+ OTP_OTP_CMD_GO_OTP_GO);
Can be wrapped into single line.
+ rc = lan9662_otp_execute(otp);
+ if (!rc) {
+ pass = lan9662_readl(OTP_OTP_PASS_FAIL(otp->base));
+ if (pass & OTP_OTP_PASS_FAIL_OTP_READ_PROHIBITED)
+ return -EACCES;
+ *dst = (u8) lan9662_readl(OTP_OTP_RD_DATA(otp->base));
+ }
+ return rc;
+}
+
...
thanks,
srini
+
+static const struct of_device_id lan9662_otp_match[] = {
+ { .compatible = "microchip,lan9662-otp", },
+ { .compatible = "microchip,lan9668-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 <horatiu.vultur@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("lan9662 OTP driver");
+MODULE_LICENSE("GPL");
