1 // SPDX-License-Identifier: GPL-2.0
2
3 /*
4 * The OCOTP driver for Sunplus SP7021
5 *
6 * Copyright (C) 2019 Sunplus Technology Inc., All rights reserved.
7 */
8
9 #include <linux/bitfield.h>
10 #include <linux/clk.h>
11 #include <linux/delay.h>
12 #include <linux/device.h>
13 #include <linux/io.h>
14 #include <linux/iopoll.h>
15 #include <linux/module.h>
16 #include <linux/mod_devicetable.h>
17 #include <linux/nvmem-provider.h>
18 #include <linux/platform_device.h>
19
20 /*
21 * OTP memory
22 * Each bank contains 4 words (32 bits).
23 * Bank 0 starts at offset 0 from the base.
24 */
25
26 #define OTP_WORDS_PER_BANK 4
27 #define OTP_WORD_SIZE sizeof(u32)
28 #define OTP_BIT_ADDR_OF_BANK (8 * OTP_WORD_SIZE * OTP_WORDS_PER_BANK)
29 #define QAC628_OTP_NUM_BANKS 8
30 #define QAC628_OTP_SIZE (QAC628_OTP_NUM_BANKS * OTP_WORDS_PER_BANK * OTP_WORD_SIZE)
31 #define OTP_READ_TIMEOUT_US 200000
32
33 /* HB_GPIO */
34 #define ADDRESS_8_DATA 0x20
35
36 /* OTP_RX */
37 #define OTP_CONTROL_2 0x48
38 #define OTP_RD_PERIOD GENMASK(15, 8)
39 #define OTP_RD_PERIOD_MASK ~GENMASK(15, 8)
40 #define CPU_CLOCK FIELD_PREP(OTP_RD_PERIOD, 30)
41 #define SEL_BAK_KEY2 BIT(5)
42 #define SEL_BAK_KEY2_MASK ~BIT(5)
43 #define SW_TRIM_EN BIT(4)
44 #define SW_TRIM_EN_MASK ~BIT(4)
45 #define SEL_BAK_KEY BIT(3)
46 #define SEL_BAK_KEY_MASK ~BIT(3)
47 #define OTP_READ BIT(2)
48 #define OTP_LOAD_SECURE_DATA BIT(1)
49 #define OTP_LOAD_SECURE_DATA_MASK ~BIT(1)
50 #define OTP_DO_CRC BIT(0)
51 #define OTP_DO_CRC_MASK ~BIT(0)
52 #define OTP_STATUS 0x4c
53 #define OTP_READ_DONE BIT(4)
54 #define OTP_READ_DONE_MASK ~BIT(4)
55 #define OTP_LOAD_SECURE_DONE_MASK ~BIT(2)
56 #define OTP_READ_ADDRESS 0x50
57
58 enum base_type {
59 HB_GPIO,
60 OTPRX,
61 BASEMAX,
62 };
63
64 struct sp_ocotp_priv {
65 struct device *dev;
66 void __iomem *base[BASEMAX];
67 struct clk *clk;
68 };
69
70 struct sp_ocotp_data {
71 int size;
72 };
73
74 static const struct sp_ocotp_data sp_otp_v0 = {
75 .size = QAC628_OTP_SIZE,
76 };
77
sp_otp_read_real(struct sp_ocotp_priv * otp,int addr,char * value)78 static int sp_otp_read_real(struct sp_ocotp_priv *otp, int addr, char *value)
79 {
80 unsigned int addr_data;
81 unsigned int byte_shift;
82 unsigned int status;
83 int ret;
84
85 addr_data = addr % (OTP_WORD_SIZE * OTP_WORDS_PER_BANK);
86 addr_data = addr_data / OTP_WORD_SIZE;
87
88 byte_shift = addr % (OTP_WORD_SIZE * OTP_WORDS_PER_BANK);
89 byte_shift = byte_shift % OTP_WORD_SIZE;
90
91 addr = addr / (OTP_WORD_SIZE * OTP_WORDS_PER_BANK);
92 addr = addr * OTP_BIT_ADDR_OF_BANK;
93
94 writel(readl(otp->base[OTPRX] + OTP_STATUS) & OTP_READ_DONE_MASK &
95 OTP_LOAD_SECURE_DONE_MASK, otp->base[OTPRX] + OTP_STATUS);
96 writel(addr, otp->base[OTPRX] + OTP_READ_ADDRESS);
97 writel(readl(otp->base[OTPRX] + OTP_CONTROL_2) | OTP_READ,
98 otp->base[OTPRX] + OTP_CONTROL_2);
99 writel(readl(otp->base[OTPRX] + OTP_CONTROL_2) & SEL_BAK_KEY2_MASK & SW_TRIM_EN_MASK
100 & SEL_BAK_KEY_MASK & OTP_LOAD_SECURE_DATA_MASK & OTP_DO_CRC_MASK,
101 otp->base[OTPRX] + OTP_CONTROL_2);
102 writel((readl(otp->base[OTPRX] + OTP_CONTROL_2) & OTP_RD_PERIOD_MASK) | CPU_CLOCK,
103 otp->base[OTPRX] + OTP_CONTROL_2);
104
105 ret = readl_poll_timeout(otp->base[OTPRX] + OTP_STATUS, status,
106 status & OTP_READ_DONE, 10, OTP_READ_TIMEOUT_US);
107
108 if (ret < 0)
109 return ret;
110
111 *value = (readl(otp->base[HB_GPIO] + ADDRESS_8_DATA + addr_data * OTP_WORD_SIZE)
112 >> (8 * byte_shift)) & 0xff;
113
114 return ret;
115 }
116
sp_ocotp_read(void * priv,unsigned int offset,void * value,size_t bytes)117 static int sp_ocotp_read(void *priv, unsigned int offset, void *value, size_t bytes)
118 {
119 struct sp_ocotp_priv *otp = priv;
120 unsigned int addr;
121 char *buf = value;
122 char val[4];
123 int ret;
124
125 ret = clk_enable(otp->clk);
126 if (ret)
127 return ret;
128
129 *buf = 0;
130 for (addr = offset; addr < (offset + bytes); addr++) {
131 ret = sp_otp_read_real(otp, addr, val);
132 if (ret < 0) {
133 dev_err(otp->dev, "OTP read fail:%d at %d", ret, addr);
134 goto disable_clk;
135 }
136
137 *buf++ = *val;
138 }
139
140 disable_clk:
141 clk_disable(otp->clk);
142
143 return ret;
144 }
145
146 static struct nvmem_config sp_ocotp_nvmem_config = {
147 .name = "sp-ocotp",
148 .add_legacy_fixed_of_cells = true,
149 .read_only = true,
150 .word_size = 1,
151 .size = QAC628_OTP_SIZE,
152 .stride = 1,
153 .reg_read = sp_ocotp_read,
154 .owner = THIS_MODULE,
155 };
156
sp_ocotp_probe(struct platform_device * pdev)157 static int sp_ocotp_probe(struct platform_device *pdev)
158 {
159 struct device *dev = &pdev->dev;
160 struct nvmem_device *nvmem;
161 struct sp_ocotp_priv *otp;
162 int ret;
163
164 otp = devm_kzalloc(dev, sizeof(*otp), GFP_KERNEL);
165 if (!otp)
166 return -ENOMEM;
167
168 otp->dev = dev;
169
170 otp->base[HB_GPIO] = devm_platform_ioremap_resource_byname(pdev, "hb_gpio");
171 if (IS_ERR(otp->base[HB_GPIO]))
172 return PTR_ERR(otp->base[HB_GPIO]);
173
174 otp->base[OTPRX] = devm_platform_ioremap_resource_byname(pdev, "otprx");
175 if (IS_ERR(otp->base[OTPRX]))
176 return PTR_ERR(otp->base[OTPRX]);
177
178 otp->clk = devm_clk_get(&pdev->dev, NULL);
179 if (IS_ERR(otp->clk))
180 return dev_err_probe(&pdev->dev, PTR_ERR(otp->clk),
181 "devm_clk_get fail\n");
182
183 ret = clk_prepare(otp->clk);
184 if (ret < 0) {
185 dev_err(dev, "failed to prepare clk: %d\n", ret);
186 return ret;
187 }
188
189 sp_ocotp_nvmem_config.priv = otp;
190 sp_ocotp_nvmem_config.dev = dev;
191
192 nvmem = devm_nvmem_register(dev, &sp_ocotp_nvmem_config);
193 if (IS_ERR(nvmem)) {
194 ret = dev_err_probe(&pdev->dev, PTR_ERR(nvmem),
195 "register nvmem device fail\n");
196 goto err;
197 }
198
199 platform_set_drvdata(pdev, nvmem);
200
201 dev_dbg(dev, "banks:%d x wpb:%d x wsize:%d = %d",
202 (int)QAC628_OTP_NUM_BANKS, (int)OTP_WORDS_PER_BANK,
203 (int)OTP_WORD_SIZE, (int)QAC628_OTP_SIZE);
204
205 return 0;
206 err:
207 clk_unprepare(otp->clk);
208 return ret;
209 }
210
211 static const struct of_device_id sp_ocotp_dt_ids[] = {
212 { .compatible = "sunplus,sp7021-ocotp", .data = &sp_otp_v0 },
213 { }
214 };
215 MODULE_DEVICE_TABLE(of, sp_ocotp_dt_ids);
216
217 static struct platform_driver sp_otp_driver = {
218 .probe = sp_ocotp_probe,
219 .driver = {
220 .name = "sunplus,sp7021-ocotp",
221 .of_match_table = sp_ocotp_dt_ids,
222 }
223 };
224 module_platform_driver(sp_otp_driver);
225
226 MODULE_AUTHOR("Vincent Shih <vincent.sunplus@gmail.com>");
227 MODULE_DESCRIPTION("Sunplus On-Chip OTP driver");
228 MODULE_LICENSE("GPL");
229
230