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 | |
39 | static int lan9662_otp_wait_flag_clear(void __iomem *reg, u32 flag) |
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(addr: pwrdn) & ~OTP_OTP_PWR_DN_OTP_PWRDN_N, addr: 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(addr: pwrdn) | OTP_OTP_PWR_DN_OTP_PWRDN_N, addr: 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(val: 0xff & (offset >> 8), OTP_OTP_ADDR_HI(otp->base)); |
79 | writel(val: 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(val: 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, up: true); |
131 | for (i = 0; i < bytes; i++) { |
132 | rc = lan9662_otp_read_byte(otp, offset: offset + i, dst: &data); |
133 | if (rc < 0) |
134 | break; |
135 | *val++ = data; |
136 | } |
137 | lan9662_otp_power(otp, up: 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, up: true); |
151 | for (i = 0; i < bytes; i++) { |
152 | /* Skip zero bytes */ |
153 | if (val[i]) { |
154 | rc = lan9662_otp_read_byte(otp, offset: offset + i, dst: &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: offset + i, |
163 | data: newdata); |
164 | if (rc < 0) |
165 | break; |
166 | } |
167 | } |
168 | lan9662_otp_power(otp, up: 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(dev: &pdev->dev, size: sizeof(*otp), GFP_KERNEL); |
189 | if (!otp) |
190 | return -ENOMEM; |
191 | |
192 | otp->dev = dev; |
193 | otp->base = devm_platform_ioremap_resource(pdev, index: 0); |
194 | if (IS_ERR(ptr: otp->base)) |
195 | return PTR_ERR(ptr: otp->base); |
196 | |
197 | otp_config.priv = otp; |
198 | otp_config.dev = dev; |
199 | |
200 | nvmem = devm_nvmem_register(dev, cfg: &otp_config); |
201 | |
202 | return PTR_ERR_OR_ZERO(ptr: nvmem); |
203 | } |
204 | |
205 | static const struct of_device_id lan9662_otp_match[] = { |
206 | { .compatible = "microchip,lan9662-otpc" , }, |
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" ); |
223 | |