Horatiu Vultur | 9e8f208 | 2022-09-16 13:20:59 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | |
| 3 | #include <linux/iopoll.h> |
| 4 | #include <linux/module.h> |
| 5 | #include <linux/nvmem-provider.h> |
| 6 | #include <linux/of.h> |
| 7 | #include <linux/platform_device.h> |
| 8 | |
| 9 | #define OTP_OTP_PWR_DN(t) (t + 0x00) |
| 10 | #define OTP_OTP_PWR_DN_OTP_PWRDN_N BIT(0) |
| 11 | #define OTP_OTP_ADDR_HI(t) (t + 0x04) |
| 12 | #define OTP_OTP_ADDR_LO(t) (t + 0x08) |
| 13 | #define OTP_OTP_PRGM_DATA(t) (t + 0x10) |
| 14 | #define OTP_OTP_PRGM_MODE(t) (t + 0x14) |
| 15 | #define OTP_OTP_PRGM_MODE_OTP_PGM_MODE_BYTE BIT(0) |
| 16 | #define OTP_OTP_RD_DATA(t) (t + 0x18) |
| 17 | #define OTP_OTP_FUNC_CMD(t) (t + 0x20) |
| 18 | #define OTP_OTP_FUNC_CMD_OTP_PROGRAM BIT(1) |
| 19 | #define OTP_OTP_FUNC_CMD_OTP_READ BIT(0) |
| 20 | #define OTP_OTP_CMD_GO(t) (t + 0x28) |
| 21 | #define OTP_OTP_CMD_GO_OTP_GO BIT(0) |
| 22 | #define OTP_OTP_PASS_FAIL(t) (t + 0x2c) |
| 23 | #define OTP_OTP_PASS_FAIL_OTP_READ_PROHIBITED BIT(3) |
| 24 | #define OTP_OTP_PASS_FAIL_OTP_WRITE_PROHIBITED BIT(2) |
| 25 | #define OTP_OTP_PASS_FAIL_OTP_FAIL BIT(0) |
| 26 | #define OTP_OTP_STATUS(t) (t + 0x30) |
| 27 | #define OTP_OTP_STATUS_OTP_CPUMPEN BIT(1) |
| 28 | #define OTP_OTP_STATUS_OTP_BUSY BIT(0) |
| 29 | |
| 30 | #define OTP_MEM_SIZE 8192 |
| 31 | #define OTP_SLEEP_US 10 |
| 32 | #define OTP_TIMEOUT_US 500000 |
| 33 | |
| 34 | struct lan9662_otp { |
| 35 | struct device *dev; |
| 36 | void __iomem *base; |
| 37 | }; |
| 38 | |
Horatiu Vultur | 022b68f | 2022-11-18 06:38:40 +0000 | [diff] [blame] | 39 | static int lan9662_otp_wait_flag_clear(void __iomem *reg, u32 flag) |
Horatiu Vultur | 9e8f208 | 2022-09-16 13:20:59 +0100 | [diff] [blame] | 40 | { |
| 41 | u32 val; |
| 42 | |
| 43 | return readl_poll_timeout(reg, val, !(val & flag), |
| 44 | OTP_SLEEP_US, OTP_TIMEOUT_US); |
| 45 | } |
| 46 | |
| 47 | static int lan9662_otp_power(struct lan9662_otp *otp, bool up) |
| 48 | { |
| 49 | void __iomem *pwrdn = OTP_OTP_PWR_DN(otp->base); |
| 50 | |
| 51 | if (up) { |
| 52 | writel(readl(pwrdn) & ~OTP_OTP_PWR_DN_OTP_PWRDN_N, pwrdn); |
| 53 | if (lan9662_otp_wait_flag_clear(OTP_OTP_STATUS(otp->base), |
| 54 | OTP_OTP_STATUS_OTP_CPUMPEN)) |
| 55 | return -ETIMEDOUT; |
| 56 | } else { |
| 57 | writel(readl(pwrdn) | OTP_OTP_PWR_DN_OTP_PWRDN_N, pwrdn); |
| 58 | } |
| 59 | |
| 60 | return 0; |
| 61 | } |
| 62 | |
| 63 | static int lan9662_otp_execute(struct lan9662_otp *otp) |
| 64 | { |
| 65 | if (lan9662_otp_wait_flag_clear(OTP_OTP_CMD_GO(otp->base), |
| 66 | OTP_OTP_CMD_GO_OTP_GO)) |
| 67 | return -ETIMEDOUT; |
| 68 | |
| 69 | if (lan9662_otp_wait_flag_clear(OTP_OTP_STATUS(otp->base), |
| 70 | OTP_OTP_STATUS_OTP_BUSY)) |
| 71 | return -ETIMEDOUT; |
| 72 | |
| 73 | return 0; |
| 74 | } |
| 75 | |
| 76 | static void lan9662_otp_set_address(struct lan9662_otp *otp, u32 offset) |
| 77 | { |
| 78 | writel(0xff & (offset >> 8), OTP_OTP_ADDR_HI(otp->base)); |
| 79 | writel(0xff & offset, OTP_OTP_ADDR_LO(otp->base)); |
| 80 | } |
| 81 | |
| 82 | static int lan9662_otp_read_byte(struct lan9662_otp *otp, u32 offset, u8 *dst) |
| 83 | { |
| 84 | u32 pass; |
| 85 | int rc; |
| 86 | |
| 87 | lan9662_otp_set_address(otp, offset); |
| 88 | writel(OTP_OTP_FUNC_CMD_OTP_READ, OTP_OTP_FUNC_CMD(otp->base)); |
| 89 | writel(OTP_OTP_CMD_GO_OTP_GO, OTP_OTP_CMD_GO(otp->base)); |
| 90 | rc = lan9662_otp_execute(otp); |
| 91 | if (!rc) { |
| 92 | pass = readl(OTP_OTP_PASS_FAIL(otp->base)); |
| 93 | if (pass & OTP_OTP_PASS_FAIL_OTP_READ_PROHIBITED) |
| 94 | return -EACCES; |
| 95 | *dst = (u8) readl(OTP_OTP_RD_DATA(otp->base)); |
| 96 | } |
| 97 | return rc; |
| 98 | } |
| 99 | |
| 100 | static int lan9662_otp_write_byte(struct lan9662_otp *otp, u32 offset, u8 data) |
| 101 | { |
| 102 | u32 pass; |
| 103 | int rc; |
| 104 | |
| 105 | lan9662_otp_set_address(otp, offset); |
| 106 | writel(OTP_OTP_PRGM_MODE_OTP_PGM_MODE_BYTE, OTP_OTP_PRGM_MODE(otp->base)); |
| 107 | writel(data, OTP_OTP_PRGM_DATA(otp->base)); |
| 108 | writel(OTP_OTP_FUNC_CMD_OTP_PROGRAM, OTP_OTP_FUNC_CMD(otp->base)); |
| 109 | writel(OTP_OTP_CMD_GO_OTP_GO, OTP_OTP_CMD_GO(otp->base)); |
| 110 | |
| 111 | rc = lan9662_otp_execute(otp); |
| 112 | if (!rc) { |
| 113 | pass = readl(OTP_OTP_PASS_FAIL(otp->base)); |
| 114 | if (pass & OTP_OTP_PASS_FAIL_OTP_WRITE_PROHIBITED) |
| 115 | return -EACCES; |
| 116 | if (pass & OTP_OTP_PASS_FAIL_OTP_FAIL) |
| 117 | return -EIO; |
| 118 | } |
| 119 | return rc; |
| 120 | } |
| 121 | |
| 122 | static int lan9662_otp_read(void *context, unsigned int offset, |
| 123 | void *_val, size_t bytes) |
| 124 | { |
| 125 | struct lan9662_otp *otp = context; |
| 126 | u8 *val = _val; |
| 127 | uint8_t data; |
| 128 | int i, rc = 0; |
| 129 | |
| 130 | lan9662_otp_power(otp, true); |
| 131 | for (i = 0; i < bytes; i++) { |
| 132 | rc = lan9662_otp_read_byte(otp, offset + i, &data); |
| 133 | if (rc < 0) |
| 134 | break; |
| 135 | *val++ = data; |
| 136 | } |
| 137 | lan9662_otp_power(otp, false); |
| 138 | |
| 139 | return rc; |
| 140 | } |
| 141 | |
| 142 | static int lan9662_otp_write(void *context, unsigned int offset, |
| 143 | void *_val, size_t bytes) |
| 144 | { |
| 145 | struct lan9662_otp *otp = context; |
| 146 | u8 *val = _val; |
| 147 | u8 data, newdata; |
| 148 | int i, rc = 0; |
| 149 | |
| 150 | lan9662_otp_power(otp, true); |
| 151 | for (i = 0; i < bytes; i++) { |
| 152 | /* Skip zero bytes */ |
| 153 | if (val[i]) { |
| 154 | rc = lan9662_otp_read_byte(otp, offset + i, &data); |
| 155 | if (rc < 0) |
| 156 | break; |
| 157 | |
| 158 | newdata = data | val[i]; |
| 159 | if (newdata == data) |
| 160 | continue; |
| 161 | |
| 162 | rc = lan9662_otp_write_byte(otp, offset + i, |
| 163 | newdata); |
| 164 | if (rc < 0) |
| 165 | break; |
| 166 | } |
| 167 | } |
| 168 | lan9662_otp_power(otp, false); |
| 169 | |
| 170 | return rc; |
| 171 | } |
| 172 | |
| 173 | static struct nvmem_config otp_config = { |
| 174 | .name = "lan9662-otp", |
| 175 | .stride = 1, |
| 176 | .word_size = 1, |
| 177 | .reg_read = lan9662_otp_read, |
| 178 | .reg_write = lan9662_otp_write, |
| 179 | .size = OTP_MEM_SIZE, |
| 180 | }; |
| 181 | |
| 182 | static int lan9662_otp_probe(struct platform_device *pdev) |
| 183 | { |
| 184 | struct device *dev = &pdev->dev; |
| 185 | struct nvmem_device *nvmem; |
| 186 | struct lan9662_otp *otp; |
| 187 | |
| 188 | otp = devm_kzalloc(&pdev->dev, sizeof(*otp), GFP_KERNEL); |
| 189 | if (!otp) |
| 190 | return -ENOMEM; |
| 191 | |
| 192 | otp->dev = dev; |
| 193 | otp->base = devm_platform_ioremap_resource(pdev, 0); |
| 194 | if (IS_ERR(otp->base)) |
| 195 | return PTR_ERR(otp->base); |
| 196 | |
| 197 | otp_config.priv = otp; |
| 198 | otp_config.dev = dev; |
| 199 | |
| 200 | nvmem = devm_nvmem_register(dev, &otp_config); |
| 201 | |
| 202 | return PTR_ERR_OR_ZERO(nvmem); |
| 203 | } |
| 204 | |
| 205 | static const struct of_device_id lan9662_otp_match[] = { |
Horatiu Vultur | 1aeb122 | 2022-09-28 21:51:12 +0200 | [diff] [blame] | 206 | { .compatible = "microchip,lan9662-otpc", }, |
Horatiu Vultur | 9e8f208 | 2022-09-16 13:20:59 +0100 | [diff] [blame] | 207 | { }, |
| 208 | }; |
| 209 | MODULE_DEVICE_TABLE(of, lan9662_otp_match); |
| 210 | |
| 211 | static struct platform_driver lan9662_otp_driver = { |
| 212 | .probe = lan9662_otp_probe, |
| 213 | .driver = { |
| 214 | .name = "lan9662-otp", |
| 215 | .of_match_table = lan9662_otp_match, |
| 216 | }, |
| 217 | }; |
| 218 | module_platform_driver(lan9662_otp_driver); |
| 219 | |
| 220 | MODULE_AUTHOR("Horatiu Vultur <horatiu.vultur@microchip.com>"); |
| 221 | MODULE_DESCRIPTION("lan9662 OTP driver"); |
| 222 | MODULE_LICENSE("GPL"); |