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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * NXP LPC18xx/LPC43xx EEPROM memory NVMEM driver
4 *
5 * Copyright (c) 2015 Ariel D'Alessandro <ariel@vanguardiasur.com>
6 */
7
8#include <linux/clk.h>
9#include <linux/device.h>
10#include <linux/delay.h>
11#include <linux/err.h>
12#include <linux/io.h>
13#include <linux/module.h>
14#include <linux/mod_devicetable.h>
15#include <linux/nvmem-provider.h>
16#include <linux/platform_device.h>
17#include <linux/reset.h>
18
19/* Registers */
20#define LPC18XX_EEPROM_AUTOPROG 0x00c
21#define LPC18XX_EEPROM_AUTOPROG_WORD 0x1
22
23#define LPC18XX_EEPROM_CLKDIV 0x014
24
25#define LPC18XX_EEPROM_PWRDWN 0x018
26#define LPC18XX_EEPROM_PWRDWN_NO 0x0
27#define LPC18XX_EEPROM_PWRDWN_YES 0x1
28
29#define LPC18XX_EEPROM_INTSTAT 0xfe0
30#define LPC18XX_EEPROM_INTSTAT_END_OF_PROG BIT(2)
31
32#define LPC18XX_EEPROM_INTSTATCLR 0xfe8
33#define LPC18XX_EEPROM_INTSTATCLR_PROG_CLR_ST BIT(2)
34
35/* Fixed page size (bytes) */
36#define LPC18XX_EEPROM_PAGE_SIZE 0x80
37
38/* EEPROM device requires a ~1500 kHz clock (min 800 kHz, max 1600 kHz) */
39#define LPC18XX_EEPROM_CLOCK_HZ 1500000
40
41/* EEPROM requires 3 ms of erase/program time between each writing */
42#define LPC18XX_EEPROM_PROGRAM_TIME 3
43
44struct lpc18xx_eeprom_dev {
45 struct clk *clk;
46 void __iomem *reg_base;
47 void __iomem *mem_base;
48 struct nvmem_device *nvmem;
49 unsigned reg_bytes;
50 unsigned val_bytes;
51 int size;
52};
53
54static inline void lpc18xx_eeprom_writel(struct lpc18xx_eeprom_dev *eeprom,
55 u32 reg, u32 val)
56{
57 writel(val, eeprom->reg_base + reg);
58}
59
60static inline u32 lpc18xx_eeprom_readl(struct lpc18xx_eeprom_dev *eeprom,
61 u32 reg)
62{
63 return readl(eeprom->reg_base + reg);
64}
65
66static int lpc18xx_eeprom_busywait_until_prog(struct lpc18xx_eeprom_dev *eeprom)
67{
68 unsigned long end;
69 u32 val;
70
71 /* Wait until EEPROM program operation has finished */
72 end = jiffies + msecs_to_jiffies(LPC18XX_EEPROM_PROGRAM_TIME * 10);
73
74 while (time_is_after_jiffies(end)) {
75 val = lpc18xx_eeprom_readl(eeprom, LPC18XX_EEPROM_INTSTAT);
76
77 if (val & LPC18XX_EEPROM_INTSTAT_END_OF_PROG) {
78 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_INTSTATCLR,
79 LPC18XX_EEPROM_INTSTATCLR_PROG_CLR_ST);
80 return 0;
81 }
82
83 usleep_range(LPC18XX_EEPROM_PROGRAM_TIME * USEC_PER_MSEC,
84 (LPC18XX_EEPROM_PROGRAM_TIME + 1) * USEC_PER_MSEC);
85 }
86
87 return -ETIMEDOUT;
88}
89
90static int lpc18xx_eeprom_gather_write(void *context, unsigned int reg,
91 void *val, size_t bytes)
92{
93 struct lpc18xx_eeprom_dev *eeprom = context;
94 unsigned int offset = reg;
95 int ret;
96
97 /*
98 * The last page contains the EEPROM initialization data and is not
99 * writable.
100 */
101 if ((reg > eeprom->size - LPC18XX_EEPROM_PAGE_SIZE) ||
102 (reg + bytes > eeprom->size - LPC18XX_EEPROM_PAGE_SIZE))
103 return -EINVAL;
104
105
106 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
107 LPC18XX_EEPROM_PWRDWN_NO);
108
109 /* Wait 100 us while the EEPROM wakes up */
110 usleep_range(100, 200);
111
112 while (bytes) {
113 writel(*(u32 *)val, eeprom->mem_base + offset);
114 ret = lpc18xx_eeprom_busywait_until_prog(eeprom);
115 if (ret < 0)
116 return ret;
117
118 bytes -= eeprom->val_bytes;
119 val += eeprom->val_bytes;
120 offset += eeprom->val_bytes;
121 }
122
123 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
124 LPC18XX_EEPROM_PWRDWN_YES);
125
126 return 0;
127}
128
129static int lpc18xx_eeprom_read(void *context, unsigned int offset,
130 void *val, size_t bytes)
131{
132 struct lpc18xx_eeprom_dev *eeprom = context;
133
134 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
135 LPC18XX_EEPROM_PWRDWN_NO);
136
137 /* Wait 100 us while the EEPROM wakes up */
138 usleep_range(100, 200);
139
140 while (bytes) {
141 *(u32 *)val = readl(eeprom->mem_base + offset);
142 bytes -= eeprom->val_bytes;
143 val += eeprom->val_bytes;
144 offset += eeprom->val_bytes;
145 }
146
147 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
148 LPC18XX_EEPROM_PWRDWN_YES);
149
150 return 0;
151}
152
153
154static struct nvmem_config lpc18xx_nvmem_config = {
155 .name = "lpc18xx-eeprom",
156 .stride = 4,
157 .word_size = 4,
158 .reg_read = lpc18xx_eeprom_read,
159 .reg_write = lpc18xx_eeprom_gather_write,
160};
161
162static int lpc18xx_eeprom_probe(struct platform_device *pdev)
163{
164 struct lpc18xx_eeprom_dev *eeprom;
165 struct device *dev = &pdev->dev;
166 struct reset_control *rst;
167 unsigned long clk_rate;
168 struct resource *res;
169 int ret;
170
171 eeprom = devm_kzalloc(dev, sizeof(*eeprom), GFP_KERNEL);
172 if (!eeprom)
173 return -ENOMEM;
174
175 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg");
176 eeprom->reg_base = devm_ioremap_resource(dev, res);
177 if (IS_ERR(eeprom->reg_base))
178 return PTR_ERR(eeprom->reg_base);
179
180 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem");
181 eeprom->mem_base = devm_ioremap_resource(dev, res);
182 if (IS_ERR(eeprom->mem_base))
183 return PTR_ERR(eeprom->mem_base);
184
185 eeprom->clk = devm_clk_get(&pdev->dev, "eeprom");
186 if (IS_ERR(eeprom->clk)) {
187 dev_err(&pdev->dev, "failed to get eeprom clock\n");
188 return PTR_ERR(eeprom->clk);
189 }
190
191 ret = clk_prepare_enable(eeprom->clk);
192 if (ret < 0) {
193 dev_err(dev, "failed to prepare/enable eeprom clk: %d\n", ret);
194 return ret;
195 }
196
197 rst = devm_reset_control_get_exclusive(dev, NULL);
198 if (IS_ERR(rst)) {
199 dev_err(dev, "failed to get reset: %ld\n", PTR_ERR(rst));
200 ret = PTR_ERR(rst);
201 goto err_clk;
202 }
203
204 ret = reset_control_assert(rst);
205 if (ret < 0) {
206 dev_err(dev, "failed to assert reset: %d\n", ret);
207 goto err_clk;
208 }
209
210 eeprom->val_bytes = 4;
211 eeprom->reg_bytes = 4;
212
213 /*
214 * Clock rate is generated by dividing the system bus clock by the
215 * division factor, contained in the divider register (minus 1 encoded).
216 */
217 clk_rate = clk_get_rate(eeprom->clk);
218 clk_rate = DIV_ROUND_UP(clk_rate, LPC18XX_EEPROM_CLOCK_HZ) - 1;
219 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_CLKDIV, clk_rate);
220
221 /*
222 * Writing a single word to the page will start the erase/program cycle
223 * automatically
224 */
225 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_AUTOPROG,
226 LPC18XX_EEPROM_AUTOPROG_WORD);
227
228 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
229 LPC18XX_EEPROM_PWRDWN_YES);
230
231 eeprom->size = resource_size(res);
232 lpc18xx_nvmem_config.size = resource_size(res);
233 lpc18xx_nvmem_config.dev = dev;
234 lpc18xx_nvmem_config.priv = eeprom;
235
236 eeprom->nvmem = devm_nvmem_register(dev, &lpc18xx_nvmem_config);
237 if (IS_ERR(eeprom->nvmem)) {
238 ret = PTR_ERR(eeprom->nvmem);
239 goto err_clk;
240 }
241
242 platform_set_drvdata(pdev, eeprom);
243
244 return 0;
245
246err_clk:
247 clk_disable_unprepare(eeprom->clk);
248
249 return ret;
250}
251
252static int lpc18xx_eeprom_remove(struct platform_device *pdev)
253{
254 struct lpc18xx_eeprom_dev *eeprom = platform_get_drvdata(pdev);
255
256 clk_disable_unprepare(eeprom->clk);
257
258 return 0;
259}
260
261static const struct of_device_id lpc18xx_eeprom_of_match[] = {
262 { .compatible = "nxp,lpc1857-eeprom" },
263 { },
264};
265MODULE_DEVICE_TABLE(of, lpc18xx_eeprom_of_match);
266
267static struct platform_driver lpc18xx_eeprom_driver = {
268 .probe = lpc18xx_eeprom_probe,
269 .remove = lpc18xx_eeprom_remove,
270 .driver = {
271 .name = "lpc18xx-eeprom",
272 .of_match_table = lpc18xx_eeprom_of_match,
273 },
274};
275
276module_platform_driver(lpc18xx_eeprom_driver);
277
278MODULE_AUTHOR("Ariel D'Alessandro <ariel@vanguardiasur.com.ar>");
279MODULE_DESCRIPTION("NXP LPC18xx EEPROM memory Driver");
280MODULE_LICENSE("GPL v2");
1/*
2 * NXP LPC18xx/LPC43xx EEPROM memory NVMEM driver
3 *
4 * Copyright (c) 2015 Ariel D'Alessandro <ariel@vanguardiasur.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 */
10
11#include <linux/clk.h>
12#include <linux/device.h>
13#include <linux/delay.h>
14#include <linux/err.h>
15#include <linux/io.h>
16#include <linux/module.h>
17#include <linux/nvmem-provider.h>
18#include <linux/platform_device.h>
19#include <linux/regmap.h>
20#include <linux/reset.h>
21
22/* Registers */
23#define LPC18XX_EEPROM_AUTOPROG 0x00c
24#define LPC18XX_EEPROM_AUTOPROG_WORD 0x1
25
26#define LPC18XX_EEPROM_CLKDIV 0x014
27
28#define LPC18XX_EEPROM_PWRDWN 0x018
29#define LPC18XX_EEPROM_PWRDWN_NO 0x0
30#define LPC18XX_EEPROM_PWRDWN_YES 0x1
31
32#define LPC18XX_EEPROM_INTSTAT 0xfe0
33#define LPC18XX_EEPROM_INTSTAT_END_OF_PROG BIT(2)
34
35#define LPC18XX_EEPROM_INTSTATCLR 0xfe8
36#define LPC18XX_EEPROM_INTSTATCLR_PROG_CLR_ST BIT(2)
37
38/* Fixed page size (bytes) */
39#define LPC18XX_EEPROM_PAGE_SIZE 0x80
40
41/* EEPROM device requires a ~1500 kHz clock (min 800 kHz, max 1600 kHz) */
42#define LPC18XX_EEPROM_CLOCK_HZ 1500000
43
44/* EEPROM requires 3 ms of erase/program time between each writing */
45#define LPC18XX_EEPROM_PROGRAM_TIME 3
46
47struct lpc18xx_eeprom_dev {
48 struct clk *clk;
49 void __iomem *reg_base;
50 void __iomem *mem_base;
51 struct nvmem_device *nvmem;
52 unsigned reg_bytes;
53 unsigned val_bytes;
54};
55
56static struct regmap_config lpc18xx_regmap_config = {
57 .reg_bits = 32,
58 .reg_stride = 4,
59 .val_bits = 32,
60};
61
62static inline void lpc18xx_eeprom_writel(struct lpc18xx_eeprom_dev *eeprom,
63 u32 reg, u32 val)
64{
65 writel(val, eeprom->reg_base + reg);
66}
67
68static inline u32 lpc18xx_eeprom_readl(struct lpc18xx_eeprom_dev *eeprom,
69 u32 reg)
70{
71 return readl(eeprom->reg_base + reg);
72}
73
74static int lpc18xx_eeprom_busywait_until_prog(struct lpc18xx_eeprom_dev *eeprom)
75{
76 unsigned long end;
77 u32 val;
78
79 /* Wait until EEPROM program operation has finished */
80 end = jiffies + msecs_to_jiffies(LPC18XX_EEPROM_PROGRAM_TIME * 10);
81
82 while (time_is_after_jiffies(end)) {
83 val = lpc18xx_eeprom_readl(eeprom, LPC18XX_EEPROM_INTSTAT);
84
85 if (val & LPC18XX_EEPROM_INTSTAT_END_OF_PROG) {
86 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_INTSTATCLR,
87 LPC18XX_EEPROM_INTSTATCLR_PROG_CLR_ST);
88 return 0;
89 }
90
91 usleep_range(LPC18XX_EEPROM_PROGRAM_TIME * USEC_PER_MSEC,
92 (LPC18XX_EEPROM_PROGRAM_TIME + 1) * USEC_PER_MSEC);
93 }
94
95 return -ETIMEDOUT;
96}
97
98static int lpc18xx_eeprom_gather_write(void *context, const void *reg,
99 size_t reg_size, const void *val,
100 size_t val_size)
101{
102 struct lpc18xx_eeprom_dev *eeprom = context;
103 unsigned int offset = *(u32 *)reg;
104 int ret;
105
106 if (offset % lpc18xx_regmap_config.reg_stride)
107 return -EINVAL;
108
109 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
110 LPC18XX_EEPROM_PWRDWN_NO);
111
112 /* Wait 100 us while the EEPROM wakes up */
113 usleep_range(100, 200);
114
115 while (val_size) {
116 writel(*(u32 *)val, eeprom->mem_base + offset);
117 ret = lpc18xx_eeprom_busywait_until_prog(eeprom);
118 if (ret < 0)
119 return ret;
120
121 val_size -= eeprom->val_bytes;
122 val += eeprom->val_bytes;
123 offset += eeprom->val_bytes;
124 }
125
126 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
127 LPC18XX_EEPROM_PWRDWN_YES);
128
129 return 0;
130}
131
132static int lpc18xx_eeprom_write(void *context, const void *data, size_t count)
133{
134 struct lpc18xx_eeprom_dev *eeprom = context;
135 unsigned int offset = eeprom->reg_bytes;
136
137 if (count <= offset)
138 return -EINVAL;
139
140 return lpc18xx_eeprom_gather_write(context, data, eeprom->reg_bytes,
141 data + offset, count - offset);
142}
143
144static int lpc18xx_eeprom_read(void *context, const void *reg, size_t reg_size,
145 void *val, size_t val_size)
146{
147 struct lpc18xx_eeprom_dev *eeprom = context;
148 unsigned int offset = *(u32 *)reg;
149
150 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
151 LPC18XX_EEPROM_PWRDWN_NO);
152
153 /* Wait 100 us while the EEPROM wakes up */
154 usleep_range(100, 200);
155
156 while (val_size) {
157 *(u32 *)val = readl(eeprom->mem_base + offset);
158 val_size -= eeprom->val_bytes;
159 val += eeprom->val_bytes;
160 offset += eeprom->val_bytes;
161 }
162
163 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
164 LPC18XX_EEPROM_PWRDWN_YES);
165
166 return 0;
167}
168
169static struct regmap_bus lpc18xx_eeprom_bus = {
170 .write = lpc18xx_eeprom_write,
171 .gather_write = lpc18xx_eeprom_gather_write,
172 .read = lpc18xx_eeprom_read,
173 .reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
174 .val_format_endian_default = REGMAP_ENDIAN_NATIVE,
175};
176
177static bool lpc18xx_eeprom_writeable_reg(struct device *dev, unsigned int reg)
178{
179 /*
180 * The last page contains the EEPROM initialization data and is not
181 * writable.
182 */
183 return reg <= lpc18xx_regmap_config.max_register -
184 LPC18XX_EEPROM_PAGE_SIZE;
185}
186
187static bool lpc18xx_eeprom_readable_reg(struct device *dev, unsigned int reg)
188{
189 return reg <= lpc18xx_regmap_config.max_register;
190}
191
192static struct nvmem_config lpc18xx_nvmem_config = {
193 .name = "lpc18xx-eeprom",
194 .owner = THIS_MODULE,
195};
196
197static int lpc18xx_eeprom_probe(struct platform_device *pdev)
198{
199 struct lpc18xx_eeprom_dev *eeprom;
200 struct device *dev = &pdev->dev;
201 struct reset_control *rst;
202 unsigned long clk_rate;
203 struct regmap *regmap;
204 struct resource *res;
205 int ret;
206
207 eeprom = devm_kzalloc(dev, sizeof(*eeprom), GFP_KERNEL);
208 if (!eeprom)
209 return -ENOMEM;
210
211 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg");
212 eeprom->reg_base = devm_ioremap_resource(dev, res);
213 if (IS_ERR(eeprom->reg_base))
214 return PTR_ERR(eeprom->reg_base);
215
216 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem");
217 eeprom->mem_base = devm_ioremap_resource(dev, res);
218 if (IS_ERR(eeprom->mem_base))
219 return PTR_ERR(eeprom->mem_base);
220
221 eeprom->clk = devm_clk_get(&pdev->dev, "eeprom");
222 if (IS_ERR(eeprom->clk)) {
223 dev_err(&pdev->dev, "failed to get eeprom clock\n");
224 return PTR_ERR(eeprom->clk);
225 }
226
227 ret = clk_prepare_enable(eeprom->clk);
228 if (ret < 0) {
229 dev_err(dev, "failed to prepare/enable eeprom clk: %d\n", ret);
230 return ret;
231 }
232
233 rst = devm_reset_control_get(dev, NULL);
234 if (IS_ERR(rst)) {
235 dev_err(dev, "failed to get reset: %ld\n", PTR_ERR(rst));
236 ret = PTR_ERR(rst);
237 goto err_clk;
238 }
239
240 ret = reset_control_assert(rst);
241 if (ret < 0) {
242 dev_err(dev, "failed to assert reset: %d\n", ret);
243 goto err_clk;
244 }
245
246 eeprom->val_bytes = lpc18xx_regmap_config.val_bits / BITS_PER_BYTE;
247 eeprom->reg_bytes = lpc18xx_regmap_config.reg_bits / BITS_PER_BYTE;
248
249 /*
250 * Clock rate is generated by dividing the system bus clock by the
251 * division factor, contained in the divider register (minus 1 encoded).
252 */
253 clk_rate = clk_get_rate(eeprom->clk);
254 clk_rate = DIV_ROUND_UP(clk_rate, LPC18XX_EEPROM_CLOCK_HZ) - 1;
255 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_CLKDIV, clk_rate);
256
257 /*
258 * Writing a single word to the page will start the erase/program cycle
259 * automatically
260 */
261 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_AUTOPROG,
262 LPC18XX_EEPROM_AUTOPROG_WORD);
263
264 lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
265 LPC18XX_EEPROM_PWRDWN_YES);
266
267 lpc18xx_regmap_config.max_register = resource_size(res) - 1;
268 lpc18xx_regmap_config.writeable_reg = lpc18xx_eeprom_writeable_reg;
269 lpc18xx_regmap_config.readable_reg = lpc18xx_eeprom_readable_reg;
270
271 regmap = devm_regmap_init(dev, &lpc18xx_eeprom_bus, eeprom,
272 &lpc18xx_regmap_config);
273 if (IS_ERR(regmap)) {
274 dev_err(dev, "regmap init failed: %ld\n", PTR_ERR(regmap));
275 ret = PTR_ERR(regmap);
276 goto err_clk;
277 }
278
279 lpc18xx_nvmem_config.dev = dev;
280
281 eeprom->nvmem = nvmem_register(&lpc18xx_nvmem_config);
282 if (IS_ERR(eeprom->nvmem)) {
283 ret = PTR_ERR(eeprom->nvmem);
284 goto err_clk;
285 }
286
287 platform_set_drvdata(pdev, eeprom);
288
289 return 0;
290
291err_clk:
292 clk_disable_unprepare(eeprom->clk);
293
294 return ret;
295}
296
297static int lpc18xx_eeprom_remove(struct platform_device *pdev)
298{
299 struct lpc18xx_eeprom_dev *eeprom = platform_get_drvdata(pdev);
300 int ret;
301
302 ret = nvmem_unregister(eeprom->nvmem);
303 if (ret < 0)
304 return ret;
305
306 clk_disable_unprepare(eeprom->clk);
307
308 return 0;
309}
310
311static const struct of_device_id lpc18xx_eeprom_of_match[] = {
312 { .compatible = "nxp,lpc1857-eeprom" },
313 { },
314};
315MODULE_DEVICE_TABLE(of, lpc18xx_eeprom_of_match);
316
317static struct platform_driver lpc18xx_eeprom_driver = {
318 .probe = lpc18xx_eeprom_probe,
319 .remove = lpc18xx_eeprom_remove,
320 .driver = {
321 .name = "lpc18xx-eeprom",
322 .of_match_table = lpc18xx_eeprom_of_match,
323 },
324};
325
326module_platform_driver(lpc18xx_eeprom_driver);
327
328MODULE_AUTHOR("Ariel D'Alessandro <ariel@vanguardiasur.com.ar>");
329MODULE_DESCRIPTION("NXP LPC18xx EEPROM memory Driver");
330MODULE_LICENSE("GPL v2");