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path: root/drivers/nvmem/lan9662-otpc.c
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Diffstat (limited to 'drivers/nvmem/lan9662-otpc.c')
-rw-r--r--drivers/nvmem/lan9662-otpc.c222
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");