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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 | ||
022b68f2 | 39 | static int lan9662_otp_wait_flag_clear(void __iomem *reg, u32 flag) |
9e8f208a HV |
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[] = { | |
1aeb122d | 206 | { .compatible = "microchip,lan9662-otpc", }, |
9e8f208a HV |
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"); |