Commit | Line | Data |
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567ec716 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2b7a5056 WS |
2 | /* |
3 | * at24.c - handle most I2C EEPROMs | |
4 | * | |
5 | * Copyright (C) 2005-2007 David Brownell | |
6 | * Copyright (C) 2008 Wolfram Sang, Pengutronix | |
2b7a5056 | 7 | */ |
4ac0d3fb | 8 | |
69afc4b6 BG |
9 | #include <linux/acpi.h> |
10 | #include <linux/bitops.h> | |
a4423ced | 11 | #include <linux/capability.h> |
69afc4b6 | 12 | #include <linux/delay.h> |
69afc4b6 | 13 | #include <linux/i2c.h> |
2b7a5056 | 14 | #include <linux/init.h> |
69afc4b6 BG |
15 | #include <linux/jiffies.h> |
16 | #include <linux/kernel.h> | |
17 | #include <linux/mod_devicetable.h> | |
2b7a5056 | 18 | #include <linux/module.h> |
2b7a5056 | 19 | #include <linux/mutex.h> |
57d15550 | 20 | #include <linux/nvmem-provider.h> |
2b0eee4f | 21 | #include <linux/of.h> |
69afc4b6 | 22 | #include <linux/of_device.h> |
98e82010 | 23 | #include <linux/pm_runtime.h> |
69afc4b6 BG |
24 | #include <linux/property.h> |
25 | #include <linux/regmap.h> | |
cd5676db | 26 | #include <linux/regulator/consumer.h> |
69afc4b6 | 27 | #include <linux/slab.h> |
2b7a5056 | 28 | |
4fa882c9 BG |
29 | /* Address pointer is 16 bit. */ |
30 | #define AT24_FLAG_ADDR16 BIT(7) | |
31 | /* sysfs-entry will be read-only. */ | |
32 | #define AT24_FLAG_READONLY BIT(6) | |
33 | /* sysfs-entry will be world-readable. */ | |
34 | #define AT24_FLAG_IRUGO BIT(5) | |
35 | /* Take always 8 addresses (24c00). */ | |
36 | #define AT24_FLAG_TAKE8ADDR BIT(4) | |
37 | /* Factory-programmed serial number. */ | |
38 | #define AT24_FLAG_SERIAL BIT(3) | |
39 | /* Factory-programmed mac address. */ | |
40 | #define AT24_FLAG_MAC BIT(2) | |
41 | /* Does not auto-rollover reads to the next slave address. */ | |
42 | #define AT24_FLAG_NO_RDROL BIT(1) | |
43 | ||
2b7a5056 WS |
44 | /* |
45 | * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable. | |
46 | * Differences between different vendor product lines (like Atmel AT24C or | |
47 | * MicroChip 24LC, etc) won't much matter for typical read/write access. | |
48 | * There are also I2C RAM chips, likewise interchangeable. One example | |
49 | * would be the PCF8570, which acts like a 24c02 EEPROM (256 bytes). | |
50 | * | |
51 | * However, misconfiguration can lose data. "Set 16-bit memory address" | |
52 | * to a part with 8-bit addressing will overwrite data. Writing with too | |
53 | * big a page size also loses data. And it's not safe to assume that the | |
54 | * conventional addresses 0x50..0x57 only hold eeproms; a PCF8563 RTC | |
55 | * uses 0x51, for just one example. | |
56 | * | |
57 | * Accordingly, explicit board-specific configuration data should be used | |
58 | * in almost all cases. (One partial exception is an SMBus used to access | |
59 | * "SPD" data for DRAM sticks. Those only use 24c02 EEPROMs.) | |
60 | * | |
61 | * So this driver uses "new style" I2C driver binding, expecting to be | |
62 | * told what devices exist. That may be in arch/X/mach-Y/board-Z.c or | |
63 | * similar kernel-resident tables; or, configuration data coming from | |
64 | * a bootloader. | |
65 | * | |
66 | * Other than binding model, current differences from "eeprom" driver are | |
67 | * that this one handles write access and isn't restricted to 24c02 devices. | |
68 | * It also handles larger devices (32 kbit and up) with two-byte addresses, | |
69 | * which won't work on pure SMBus systems. | |
70 | */ | |
71 | ||
72 | struct at24_data { | |
2b7a5056 WS |
73 | /* |
74 | * Lock protects against activities from other Linux tasks, | |
75 | * but not from changes by other I2C masters. | |
76 | */ | |
77 | struct mutex lock; | |
2b7a5056 | 78 | |
aa4ce228 BG |
79 | unsigned int write_max; |
80 | unsigned int num_addresses; | |
4bb5c13c | 81 | unsigned int offset_adj; |
2b7a5056 | 82 | |
7c280664 BG |
83 | u32 byte_len; |
84 | u16 page_size; | |
85 | u8 flags; | |
86 | ||
57d15550 | 87 | struct nvmem_device *nvmem; |
cd5676db | 88 | struct regulator *vcc_reg; |
a4423ced | 89 | void (*read_post)(unsigned int off, char *buf, size_t count); |
57d15550 | 90 | |
2b7a5056 WS |
91 | /* |
92 | * Some chips tie up multiple I2C addresses; dummy devices reserve | |
92e17647 | 93 | * them for us. |
2b7a5056 | 94 | */ |
d08aea21 | 95 | u8 bank_addr_shift; |
997a29bb | 96 | struct regmap *client_regmaps[] __counted_by(num_addresses); |
2b7a5056 WS |
97 | }; |
98 | ||
99 | /* | |
100 | * This parameter is to help this driver avoid blocking other drivers out | |
101 | * of I2C for potentially troublesome amounts of time. With a 100 kHz I2C | |
102 | * clock, one 256 byte read takes about 1/43 second which is excessive; | |
103 | * but the 1/170 second it takes at 400 kHz may be quite reasonable; and | |
104 | * at 1 MHz (Fm+) a 1/430 second delay could easily be invisible. | |
105 | * | |
106 | * This value is forced to be a power of two so that writes align on pages. | |
107 | */ | |
ec3c2d51 BG |
108 | static unsigned int at24_io_limit = 128; |
109 | module_param_named(io_limit, at24_io_limit, uint, 0); | |
110 | MODULE_PARM_DESC(at24_io_limit, "Maximum bytes per I/O (default 128)"); | |
2b7a5056 WS |
111 | |
112 | /* | |
113 | * Specs often allow 5 msec for a page write, sometimes 20 msec; | |
114 | * it's important to recover from write timeouts. | |
115 | */ | |
ec3c2d51 BG |
116 | static unsigned int at24_write_timeout = 25; |
117 | module_param_named(write_timeout, at24_write_timeout, uint, 0); | |
118 | MODULE_PARM_DESC(at24_write_timeout, "Time (in ms) to try writes (default 25)"); | |
2b7a5056 | 119 | |
b680f4fa | 120 | struct at24_chip_data { |
b680f4fa SVA |
121 | u32 byte_len; |
122 | u8 flags; | |
d08aea21 | 123 | u8 bank_addr_shift; |
a4423ced | 124 | void (*read_post)(unsigned int off, char *buf, size_t count); |
b680f4fa SVA |
125 | }; |
126 | ||
127 | #define AT24_CHIP_DATA(_name, _len, _flags) \ | |
128 | static const struct at24_chip_data _name = { \ | |
129 | .byte_len = _len, .flags = _flags, \ | |
130 | } | |
131 | ||
a4423ced JD |
132 | #define AT24_CHIP_DATA_CB(_name, _len, _flags, _read_post) \ |
133 | static const struct at24_chip_data _name = { \ | |
134 | .byte_len = _len, .flags = _flags, \ | |
135 | .read_post = _read_post, \ | |
136 | } | |
137 | ||
d08aea21 MK |
138 | #define AT24_CHIP_DATA_BS(_name, _len, _flags, _bank_addr_shift) \ |
139 | static const struct at24_chip_data _name = { \ | |
140 | .byte_len = _len, .flags = _flags, \ | |
141 | .bank_addr_shift = _bank_addr_shift \ | |
142 | } | |
143 | ||
a4423ced JD |
144 | static void at24_read_post_vaio(unsigned int off, char *buf, size_t count) |
145 | { | |
146 | int i; | |
147 | ||
148 | if (capable(CAP_SYS_ADMIN)) | |
149 | return; | |
150 | ||
151 | /* | |
152 | * Hide VAIO private settings to regular users: | |
153 | * - BIOS passwords: bytes 0x00 to 0x0f | |
154 | * - UUID: bytes 0x10 to 0x1f | |
155 | * - Serial number: 0xc0 to 0xdf | |
156 | */ | |
157 | for (i = 0; i < count; i++) { | |
158 | if ((off + i <= 0x1f) || | |
159 | (off + i >= 0xc0 && off + i <= 0xdf)) | |
160 | buf[i] = 0; | |
161 | } | |
162 | } | |
163 | ||
b680f4fa SVA |
164 | /* needs 8 addresses as A0-A2 are ignored */ |
165 | AT24_CHIP_DATA(at24_data_24c00, 128 / 8, AT24_FLAG_TAKE8ADDR); | |
166 | /* old variants can't be handled with this generic entry! */ | |
167 | AT24_CHIP_DATA(at24_data_24c01, 1024 / 8, 0); | |
168 | AT24_CHIP_DATA(at24_data_24cs01, 16, | |
169 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); | |
170 | AT24_CHIP_DATA(at24_data_24c02, 2048 / 8, 0); | |
171 | AT24_CHIP_DATA(at24_data_24cs02, 16, | |
172 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); | |
173 | AT24_CHIP_DATA(at24_data_24mac402, 48 / 8, | |
174 | AT24_FLAG_MAC | AT24_FLAG_READONLY); | |
175 | AT24_CHIP_DATA(at24_data_24mac602, 64 / 8, | |
176 | AT24_FLAG_MAC | AT24_FLAG_READONLY); | |
177 | /* spd is a 24c02 in memory DIMMs */ | |
178 | AT24_CHIP_DATA(at24_data_spd, 2048 / 8, | |
179 | AT24_FLAG_READONLY | AT24_FLAG_IRUGO); | |
a4423ced JD |
180 | /* 24c02_vaio is a 24c02 on some Sony laptops */ |
181 | AT24_CHIP_DATA_CB(at24_data_24c02_vaio, 2048 / 8, | |
182 | AT24_FLAG_READONLY | AT24_FLAG_IRUGO, | |
183 | at24_read_post_vaio); | |
b680f4fa SVA |
184 | AT24_CHIP_DATA(at24_data_24c04, 4096 / 8, 0); |
185 | AT24_CHIP_DATA(at24_data_24cs04, 16, | |
186 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); | |
187 | /* 24rf08 quirk is handled at i2c-core */ | |
188 | AT24_CHIP_DATA(at24_data_24c08, 8192 / 8, 0); | |
189 | AT24_CHIP_DATA(at24_data_24cs08, 16, | |
190 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); | |
191 | AT24_CHIP_DATA(at24_data_24c16, 16384 / 8, 0); | |
192 | AT24_CHIP_DATA(at24_data_24cs16, 16, | |
193 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); | |
194 | AT24_CHIP_DATA(at24_data_24c32, 32768 / 8, AT24_FLAG_ADDR16); | |
4791146e MV |
195 | /* M24C32-D Additional Write lockable page (M24C32-D order codes) */ |
196 | AT24_CHIP_DATA(at24_data_24c32d_wlp, 32, AT24_FLAG_ADDR16); | |
b680f4fa SVA |
197 | AT24_CHIP_DATA(at24_data_24cs32, 16, |
198 | AT24_FLAG_ADDR16 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); | |
199 | AT24_CHIP_DATA(at24_data_24c64, 65536 / 8, AT24_FLAG_ADDR16); | |
3774740f AS |
200 | /* M24C64-D Additional Write lockable page (M24C64-D order codes) */ |
201 | AT24_CHIP_DATA(at24_data_24c64d_wlp, 32, AT24_FLAG_ADDR16); | |
b680f4fa SVA |
202 | AT24_CHIP_DATA(at24_data_24cs64, 16, |
203 | AT24_FLAG_ADDR16 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); | |
204 | AT24_CHIP_DATA(at24_data_24c128, 131072 / 8, AT24_FLAG_ADDR16); | |
205 | AT24_CHIP_DATA(at24_data_24c256, 262144 / 8, AT24_FLAG_ADDR16); | |
206 | AT24_CHIP_DATA(at24_data_24c512, 524288 / 8, AT24_FLAG_ADDR16); | |
207 | AT24_CHIP_DATA(at24_data_24c1024, 1048576 / 8, AT24_FLAG_ADDR16); | |
d08aea21 | 208 | AT24_CHIP_DATA_BS(at24_data_24c1025, 1048576 / 8, AT24_FLAG_ADDR16, 2); |
37cf28d3 | 209 | AT24_CHIP_DATA(at24_data_24c2048, 2097152 / 8, AT24_FLAG_ADDR16); |
b680f4fa SVA |
210 | /* identical to 24c08 ? */ |
211 | AT24_CHIP_DATA(at24_data_INT3499, 8192 / 8, 0); | |
212 | ||
2b7a5056 | 213 | static const struct i2c_device_id at24_ids[] = { |
b680f4fa SVA |
214 | { "24c00", (kernel_ulong_t)&at24_data_24c00 }, |
215 | { "24c01", (kernel_ulong_t)&at24_data_24c01 }, | |
216 | { "24cs01", (kernel_ulong_t)&at24_data_24cs01 }, | |
217 | { "24c02", (kernel_ulong_t)&at24_data_24c02 }, | |
218 | { "24cs02", (kernel_ulong_t)&at24_data_24cs02 }, | |
219 | { "24mac402", (kernel_ulong_t)&at24_data_24mac402 }, | |
220 | { "24mac602", (kernel_ulong_t)&at24_data_24mac602 }, | |
221 | { "spd", (kernel_ulong_t)&at24_data_spd }, | |
a4423ced | 222 | { "24c02-vaio", (kernel_ulong_t)&at24_data_24c02_vaio }, |
b680f4fa SVA |
223 | { "24c04", (kernel_ulong_t)&at24_data_24c04 }, |
224 | { "24cs04", (kernel_ulong_t)&at24_data_24cs04 }, | |
225 | { "24c08", (kernel_ulong_t)&at24_data_24c08 }, | |
226 | { "24cs08", (kernel_ulong_t)&at24_data_24cs08 }, | |
227 | { "24c16", (kernel_ulong_t)&at24_data_24c16 }, | |
228 | { "24cs16", (kernel_ulong_t)&at24_data_24cs16 }, | |
229 | { "24c32", (kernel_ulong_t)&at24_data_24c32 }, | |
4791146e | 230 | { "24c32d-wl", (kernel_ulong_t)&at24_data_24c32d_wlp }, |
b680f4fa SVA |
231 | { "24cs32", (kernel_ulong_t)&at24_data_24cs32 }, |
232 | { "24c64", (kernel_ulong_t)&at24_data_24c64 }, | |
3774740f | 233 | { "24c64-wl", (kernel_ulong_t)&at24_data_24c64d_wlp }, |
b680f4fa SVA |
234 | { "24cs64", (kernel_ulong_t)&at24_data_24cs64 }, |
235 | { "24c128", (kernel_ulong_t)&at24_data_24c128 }, | |
236 | { "24c256", (kernel_ulong_t)&at24_data_24c256 }, | |
237 | { "24c512", (kernel_ulong_t)&at24_data_24c512 }, | |
238 | { "24c1024", (kernel_ulong_t)&at24_data_24c1024 }, | |
d08aea21 | 239 | { "24c1025", (kernel_ulong_t)&at24_data_24c1025 }, |
37cf28d3 | 240 | { "24c2048", (kernel_ulong_t)&at24_data_24c2048 }, |
b680f4fa | 241 | { "at24", 0 }, |
2b7a5056 WS |
242 | { /* END OF LIST */ } |
243 | }; | |
244 | MODULE_DEVICE_TABLE(i2c, at24_ids); | |
245 | ||
2b0eee4f | 246 | static const struct of_device_id __maybe_unused at24_of_match[] = { |
b680f4fa SVA |
247 | { .compatible = "atmel,24c00", .data = &at24_data_24c00 }, |
248 | { .compatible = "atmel,24c01", .data = &at24_data_24c01 }, | |
0f30aca7 | 249 | { .compatible = "atmel,24cs01", .data = &at24_data_24cs01 }, |
b680f4fa | 250 | { .compatible = "atmel,24c02", .data = &at24_data_24c02 }, |
0f30aca7 BG |
251 | { .compatible = "atmel,24cs02", .data = &at24_data_24cs02 }, |
252 | { .compatible = "atmel,24mac402", .data = &at24_data_24mac402 }, | |
253 | { .compatible = "atmel,24mac602", .data = &at24_data_24mac602 }, | |
b680f4fa SVA |
254 | { .compatible = "atmel,spd", .data = &at24_data_spd }, |
255 | { .compatible = "atmel,24c04", .data = &at24_data_24c04 }, | |
0f30aca7 | 256 | { .compatible = "atmel,24cs04", .data = &at24_data_24cs04 }, |
b680f4fa | 257 | { .compatible = "atmel,24c08", .data = &at24_data_24c08 }, |
0f30aca7 | 258 | { .compatible = "atmel,24cs08", .data = &at24_data_24cs08 }, |
b680f4fa | 259 | { .compatible = "atmel,24c16", .data = &at24_data_24c16 }, |
0f30aca7 | 260 | { .compatible = "atmel,24cs16", .data = &at24_data_24cs16 }, |
b680f4fa | 261 | { .compatible = "atmel,24c32", .data = &at24_data_24c32 }, |
4791146e | 262 | { .compatible = "atmel,24c32d-wl", .data = &at24_data_24c32d_wlp }, |
0f30aca7 | 263 | { .compatible = "atmel,24cs32", .data = &at24_data_24cs32 }, |
b680f4fa | 264 | { .compatible = "atmel,24c64", .data = &at24_data_24c64 }, |
3774740f | 265 | { .compatible = "atmel,24c64d-wl", .data = &at24_data_24c64d_wlp }, |
0f30aca7 | 266 | { .compatible = "atmel,24cs64", .data = &at24_data_24cs64 }, |
b680f4fa SVA |
267 | { .compatible = "atmel,24c128", .data = &at24_data_24c128 }, |
268 | { .compatible = "atmel,24c256", .data = &at24_data_24c256 }, | |
269 | { .compatible = "atmel,24c512", .data = &at24_data_24c512 }, | |
270 | { .compatible = "atmel,24c1024", .data = &at24_data_24c1024 }, | |
d08aea21 | 271 | { .compatible = "atmel,24c1025", .data = &at24_data_24c1025 }, |
37cf28d3 | 272 | { .compatible = "atmel,24c2048", .data = &at24_data_24c2048 }, |
b680f4fa | 273 | { /* END OF LIST */ }, |
7f2a2f0d JMC |
274 | }; |
275 | MODULE_DEVICE_TABLE(of, at24_of_match); | |
276 | ||
8965930c | 277 | static const struct acpi_device_id __maybe_unused at24_acpi_ids[] = { |
b680f4fa | 278 | { "INT3499", (kernel_ulong_t)&at24_data_INT3499 }, |
4837621c | 279 | { "TPF0001", (kernel_ulong_t)&at24_data_24c1024 }, |
b680f4fa | 280 | { /* END OF LIST */ } |
40d8edc9 AS |
281 | }; |
282 | MODULE_DEVICE_TABLE(acpi, at24_acpi_ids); | |
283 | ||
2b7a5056 WS |
284 | /* |
285 | * This routine supports chips which consume multiple I2C addresses. It | |
286 | * computes the addressing information to be used for a given r/w request. | |
287 | * Assumes that sanity checks for offset happened at sysfs-layer. | |
9afd6866 BG |
288 | * |
289 | * Slave address and byte offset derive from the offset. Always | |
290 | * set the byte address; on a multi-master board, another master | |
291 | * may have changed the chip's "current" address pointer. | |
2b7a5056 | 292 | */ |
92e17647 HK |
293 | static struct regmap *at24_translate_offset(struct at24_data *at24, |
294 | unsigned int *offset) | |
2b7a5056 | 295 | { |
aa4ce228 | 296 | unsigned int i; |
2b7a5056 | 297 | |
7c280664 | 298 | if (at24->flags & AT24_FLAG_ADDR16) { |
2b7a5056 WS |
299 | i = *offset >> 16; |
300 | *offset &= 0xffff; | |
301 | } else { | |
302 | i = *offset >> 8; | |
303 | *offset &= 0xff; | |
304 | } | |
305 | ||
92e17647 | 306 | return at24->client_regmaps[i]; |
2b7a5056 WS |
307 | } |
308 | ||
f1a640c5 BG |
309 | static struct device *at24_base_client_dev(struct at24_data *at24) |
310 | { | |
92e17647 | 311 | return regmap_get_device(at24->client_regmaps[0]); |
f1a640c5 BG |
312 | } |
313 | ||
e32213fb SVA |
314 | static size_t at24_adjust_read_count(struct at24_data *at24, |
315 | unsigned int offset, size_t count) | |
316 | { | |
317 | unsigned int bits; | |
318 | size_t remainder; | |
319 | ||
320 | /* | |
321 | * In case of multi-address chips that don't rollover reads to | |
322 | * the next slave address: truncate the count to the slave boundary, | |
323 | * so that the read never straddles slaves. | |
324 | */ | |
7c280664 BG |
325 | if (at24->flags & AT24_FLAG_NO_RDROL) { |
326 | bits = (at24->flags & AT24_FLAG_ADDR16) ? 16 : 8; | |
e32213fb SVA |
327 | remainder = BIT(bits) - offset; |
328 | if (count > remainder) | |
329 | count = remainder; | |
330 | } | |
331 | ||
ec3c2d51 BG |
332 | if (count > at24_io_limit) |
333 | count = at24_io_limit; | |
e32213fb SVA |
334 | |
335 | return count; | |
336 | } | |
337 | ||
4bb5c13c HK |
338 | static ssize_t at24_regmap_read(struct at24_data *at24, char *buf, |
339 | unsigned int offset, size_t count) | |
340 | { | |
341 | unsigned long timeout, read_time; | |
4bb5c13c HK |
342 | struct regmap *regmap; |
343 | int ret; | |
344 | ||
92e17647 | 345 | regmap = at24_translate_offset(at24, &offset); |
e32213fb | 346 | count = at24_adjust_read_count(at24, offset, count); |
4bb5c13c HK |
347 | |
348 | /* adjust offset for mac and serial read ops */ | |
349 | offset += at24->offset_adj; | |
350 | ||
9a9e295e WX |
351 | timeout = jiffies + msecs_to_jiffies(at24_write_timeout); |
352 | do { | |
353 | /* | |
354 | * The timestamp shall be taken before the actual operation | |
355 | * to avoid a premature timeout in case of high CPU load. | |
356 | */ | |
357 | read_time = jiffies; | |
358 | ||
4bb5c13c | 359 | ret = regmap_bulk_read(regmap, offset, buf, count); |
92e17647 | 360 | dev_dbg(regmap_get_device(regmap), "read %zu@%d --> %d (%ld)\n", |
4bb5c13c HK |
361 | count, offset, ret, jiffies); |
362 | if (!ret) | |
363 | return count; | |
9a9e295e WX |
364 | |
365 | usleep_range(1000, 1500); | |
366 | } while (time_before(read_time, timeout)); | |
4bb5c13c HK |
367 | |
368 | return -ETIMEDOUT; | |
369 | } | |
370 | ||
2b7a5056 WS |
371 | /* |
372 | * Note that if the hardware write-protect pin is pulled high, the whole | |
373 | * chip is normally write protected. But there are plenty of product | |
374 | * variants here, including OTP fuses and partial chip protect. | |
375 | * | |
cd0c8615 BG |
376 | * We only use page mode writes; the alternative is sloooow. These routines |
377 | * write at most one page. | |
2b7a5056 | 378 | */ |
cd0c8615 BG |
379 | |
380 | static size_t at24_adjust_write_count(struct at24_data *at24, | |
381 | unsigned int offset, size_t count) | |
2b7a5056 | 382 | { |
aa4ce228 | 383 | unsigned int next_page; |
2b7a5056 | 384 | |
2b7a5056 WS |
385 | /* write_max is at most a page */ |
386 | if (count > at24->write_max) | |
387 | count = at24->write_max; | |
388 | ||
389 | /* Never roll over backwards, to the start of this page */ | |
7c280664 | 390 | next_page = roundup(offset + 1, at24->page_size); |
2b7a5056 WS |
391 | if (offset + count > next_page) |
392 | count = next_page - offset; | |
393 | ||
cd0c8615 BG |
394 | return count; |
395 | } | |
396 | ||
8e5888e1 HK |
397 | static ssize_t at24_regmap_write(struct at24_data *at24, const char *buf, |
398 | unsigned int offset, size_t count) | |
399 | { | |
400 | unsigned long timeout, write_time; | |
8e5888e1 HK |
401 | struct regmap *regmap; |
402 | int ret; | |
403 | ||
92e17647 | 404 | regmap = at24_translate_offset(at24, &offset); |
8e5888e1 | 405 | count = at24_adjust_write_count(at24, offset, count); |
9a9e295e WX |
406 | timeout = jiffies + msecs_to_jiffies(at24_write_timeout); |
407 | ||
408 | do { | |
409 | /* | |
410 | * The timestamp shall be taken before the actual operation | |
411 | * to avoid a premature timeout in case of high CPU load. | |
412 | */ | |
413 | write_time = jiffies; | |
8e5888e1 | 414 | |
8e5888e1 | 415 | ret = regmap_bulk_write(regmap, offset, buf, count); |
92e17647 | 416 | dev_dbg(regmap_get_device(regmap), "write %zu@%d --> %d (%ld)\n", |
8e5888e1 HK |
417 | count, offset, ret, jiffies); |
418 | if (!ret) | |
419 | return count; | |
9a9e295e WX |
420 | |
421 | usleep_range(1000, 1500); | |
422 | } while (time_before(write_time, timeout)); | |
8e5888e1 HK |
423 | |
424 | return -ETIMEDOUT; | |
425 | } | |
426 | ||
d5bc0047 BG |
427 | static int at24_read(void *priv, unsigned int off, void *val, size_t count) |
428 | { | |
5ca2b5b7 BG |
429 | struct at24_data *at24; |
430 | struct device *dev; | |
d5bc0047 | 431 | char *buf = val; |
99363d1c | 432 | int i, ret; |
d5bc0047 | 433 | |
5ca2b5b7 | 434 | at24 = priv; |
f1a640c5 | 435 | dev = at24_base_client_dev(at24); |
5ca2b5b7 | 436 | |
d5bc0047 BG |
437 | if (unlikely(!count)) |
438 | return count; | |
439 | ||
7c280664 | 440 | if (off + count > at24->byte_len) |
d9bcd462 HK |
441 | return -EINVAL; |
442 | ||
e68f4871 HK |
443 | ret = pm_runtime_resume_and_get(dev); |
444 | if (ret) | |
98e82010 | 445 | return ret; |
d5bc0047 BG |
446 | /* |
447 | * Read data from chip, protecting against concurrent updates | |
448 | * from this host, but not from other I2C masters. | |
449 | */ | |
450 | mutex_lock(&at24->lock); | |
451 | ||
99363d1c JD |
452 | for (i = 0; count; i += ret, count -= ret) { |
453 | ret = at24_regmap_read(at24, buf + i, off + i, count); | |
eb27fde2 | 454 | if (ret < 0) { |
d5bc0047 | 455 | mutex_unlock(&at24->lock); |
f9ecc83f | 456 | pm_runtime_put(dev); |
eb27fde2 | 457 | return ret; |
d5bc0047 | 458 | } |
d5bc0047 BG |
459 | } |
460 | ||
461 | mutex_unlock(&at24->lock); | |
462 | ||
f9ecc83f | 463 | pm_runtime_put(dev); |
98e82010 | 464 | |
a4423ced | 465 | if (unlikely(at24->read_post)) |
99363d1c | 466 | at24->read_post(off, buf, i); |
a4423ced | 467 | |
d5bc0047 BG |
468 | return 0; |
469 | } | |
470 | ||
cf0361a2 | 471 | static int at24_write(void *priv, unsigned int off, void *val, size_t count) |
2b7a5056 | 472 | { |
5ca2b5b7 BG |
473 | struct at24_data *at24; |
474 | struct device *dev; | |
cf0361a2 | 475 | char *buf = val; |
98e82010 | 476 | int ret; |
2b7a5056 | 477 | |
5ca2b5b7 | 478 | at24 = priv; |
f1a640c5 | 479 | dev = at24_base_client_dev(at24); |
5ca2b5b7 | 480 | |
2b7a5056 | 481 | if (unlikely(!count)) |
cf0361a2 | 482 | return -EINVAL; |
2b7a5056 | 483 | |
7c280664 | 484 | if (off + count > at24->byte_len) |
d9bcd462 HK |
485 | return -EINVAL; |
486 | ||
e68f4871 HK |
487 | ret = pm_runtime_resume_and_get(dev); |
488 | if (ret) | |
98e82010 | 489 | return ret; |
2b7a5056 WS |
490 | /* |
491 | * Write data to chip, protecting against concurrent updates | |
492 | * from this host, but not from other I2C masters. | |
493 | */ | |
494 | mutex_lock(&at24->lock); | |
495 | ||
496 | while (count) { | |
c4fee330 BG |
497 | ret = at24_regmap_write(at24, buf, off, count); |
498 | if (ret < 0) { | |
cf0361a2 | 499 | mutex_unlock(&at24->lock); |
f9ecc83f | 500 | pm_runtime_put(dev); |
c4fee330 | 501 | return ret; |
2b7a5056 | 502 | } |
c4fee330 BG |
503 | buf += ret; |
504 | off += ret; | |
505 | count -= ret; | |
2b7a5056 WS |
506 | } |
507 | ||
508 | mutex_unlock(&at24->lock); | |
509 | ||
f9ecc83f | 510 | pm_runtime_put(dev); |
98e82010 | 511 | |
57d15550 AL |
512 | return 0; |
513 | } | |
514 | ||
73b0d922 | 515 | static int at24_make_dummy_client(struct at24_data *at24, unsigned int index, |
92e17647 | 516 | struct i2c_client *base_client, |
73b0d922 BG |
517 | struct regmap_config *regmap_config) |
518 | { | |
92e17647 | 519 | struct i2c_client *dummy_client; |
73b0d922 | 520 | struct regmap *regmap; |
73b0d922 | 521 | |
92e17647 HK |
522 | dummy_client = devm_i2c_new_dummy_device(&base_client->dev, |
523 | base_client->adapter, | |
d08aea21 MK |
524 | base_client->addr + |
525 | (index << at24->bank_addr_shift)); | |
e7308628 BG |
526 | if (IS_ERR(dummy_client)) |
527 | return PTR_ERR(dummy_client); | |
73b0d922 BG |
528 | |
529 | regmap = devm_regmap_init_i2c(dummy_client, regmap_config); | |
e7308628 | 530 | if (IS_ERR(regmap)) |
73b0d922 | 531 | return PTR_ERR(regmap); |
73b0d922 | 532 | |
92e17647 | 533 | at24->client_regmaps[index] = regmap; |
73b0d922 BG |
534 | |
535 | return 0; | |
536 | } | |
537 | ||
4bb5c13c HK |
538 | static unsigned int at24_get_offset_adj(u8 flags, unsigned int byte_len) |
539 | { | |
540 | if (flags & AT24_FLAG_MAC) { | |
541 | /* EUI-48 starts from 0x9a, EUI-64 from 0x98 */ | |
542 | return 0xa0 - byte_len; | |
543 | } else if (flags & AT24_FLAG_SERIAL && flags & AT24_FLAG_ADDR16) { | |
544 | /* | |
545 | * For 16 bit address pointers, the word address must contain | |
546 | * a '10' sequence in bits 11 and 10 regardless of the | |
547 | * intended position of the address pointer. | |
548 | */ | |
549 | return 0x0800; | |
550 | } else if (flags & AT24_FLAG_SERIAL) { | |
551 | /* | |
552 | * Otherwise the word address must begin with a '10' sequence, | |
553 | * regardless of the intended address. | |
554 | */ | |
555 | return 0x0080; | |
556 | } else { | |
557 | return 0; | |
558 | } | |
559 | } | |
560 | ||
caba40ec HK |
561 | static void at24_probe_temp_sensor(struct i2c_client *client) |
562 | { | |
563 | struct at24_data *at24 = i2c_get_clientdata(client); | |
564 | struct i2c_board_info info = { .type = "jc42" }; | |
565 | int ret; | |
566 | u8 val; | |
567 | ||
568 | /* | |
569 | * Byte 2 has value 11 for DDR3, earlier versions don't | |
570 | * support the thermal sensor present flag | |
571 | */ | |
572 | ret = at24_read(at24, 2, &val, 1); | |
573 | if (ret || val != 11) | |
574 | return; | |
575 | ||
576 | /* Byte 32, bit 7 is set if temp sensor is present */ | |
577 | ret = at24_read(at24, 32, &val, 1); | |
578 | if (ret || !(val & BIT(7))) | |
579 | return; | |
580 | ||
581 | info.addr = 0x18 | (client->addr & 7); | |
582 | ||
583 | i2c_new_client_device(client->adapter, &info); | |
584 | } | |
585 | ||
48b6a7d1 | 586 | static int at24_probe(struct i2c_client *client) |
2b7a5056 | 587 | { |
eef69398 | 588 | struct regmap_config regmap_config = { }; |
8cdc4e7e | 589 | struct nvmem_config nvmem_config = { }; |
4fa882c9 BG |
590 | u32 byte_len, page_size, flags, addrw; |
591 | const struct at24_chip_data *cdata; | |
021c7d7b | 592 | struct device *dev = &client->dev; |
34d43faf | 593 | bool i2c_fn_i2c, i2c_fn_block; |
5ca2b5b7 BG |
594 | unsigned int i, num_addresses; |
595 | struct at24_data *at24; | |
1e96078e | 596 | bool full_power; |
551a1266 | 597 | struct regmap *regmap; |
5ca2b5b7 | 598 | bool writable; |
00f0ea70 | 599 | u8 test_byte; |
5ca2b5b7 | 600 | int err; |
2b7a5056 | 601 | |
34d43faf BG |
602 | i2c_fn_i2c = i2c_check_functionality(client->adapter, I2C_FUNC_I2C); |
603 | i2c_fn_block = i2c_check_functionality(client->adapter, | |
604 | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK); | |
605 | ||
4cdc5dbb BD |
606 | cdata = i2c_get_match_data(client); |
607 | if (!cdata) | |
608 | return -ENODEV; | |
4fa882c9 BG |
609 | |
610 | err = device_property_read_u32(dev, "pagesize", &page_size); | |
feb2f19b | 611 | if (err) |
4fa882c9 BG |
612 | /* |
613 | * This is slow, but we can't know all eeproms, so we better | |
dce91ba3 BG |
614 | * play safe. Specifying custom eeprom-types via device tree |
615 | * or properties is recommended anyhow. | |
4fa882c9 BG |
616 | */ |
617 | page_size = 1; | |
618 | ||
619 | flags = cdata->flags; | |
620 | if (device_property_present(dev, "read-only")) | |
621 | flags |= AT24_FLAG_READONLY; | |
622 | if (device_property_present(dev, "no-read-rollover")) | |
623 | flags |= AT24_FLAG_NO_RDROL; | |
624 | ||
625 | err = device_property_read_u32(dev, "address-width", &addrw); | |
626 | if (!err) { | |
627 | switch (addrw) { | |
628 | case 8: | |
629 | if (flags & AT24_FLAG_ADDR16) | |
630 | dev_warn(dev, | |
631 | "Override address width to be 8, while default is 16\n"); | |
632 | flags &= ~AT24_FLAG_ADDR16; | |
633 | break; | |
634 | case 16: | |
635 | flags |= AT24_FLAG_ADDR16; | |
636 | break; | |
637 | default: | |
638 | dev_warn(dev, "Bad \"address-width\" property: %u\n", | |
639 | addrw); | |
640 | } | |
641 | } | |
642 | ||
643 | err = device_property_read_u32(dev, "size", &byte_len); | |
644 | if (err) | |
645 | byte_len = cdata->byte_len; | |
2b7a5056 | 646 | |
34d43faf | 647 | if (!i2c_fn_i2c && !i2c_fn_block) |
4fa882c9 | 648 | page_size = 1; |
551a1266 | 649 | |
4fa882c9 | 650 | if (!page_size) { |
021c7d7b | 651 | dev_err(dev, "page_size must not be 0!\n"); |
f0ac2363 | 652 | return -EINVAL; |
45efe847 | 653 | } |
de5db101 | 654 | |
4fa882c9 | 655 | if (!is_power_of_2(page_size)) |
021c7d7b | 656 | dev_warn(dev, "page_size looks suspicious (no power of 2)!\n"); |
2b7a5056 | 657 | |
950bcbbe BG |
658 | err = device_property_read_u32(dev, "num-addresses", &num_addresses); |
659 | if (err) { | |
660 | if (flags & AT24_FLAG_TAKE8ADDR) | |
661 | num_addresses = 8; | |
662 | else | |
663 | num_addresses = DIV_ROUND_UP(byte_len, | |
664 | (flags & AT24_FLAG_ADDR16) ? 65536 : 256); | |
665 | } | |
2b7a5056 | 666 | |
4fa882c9 | 667 | if ((flags & AT24_FLAG_SERIAL) && (flags & AT24_FLAG_MAC)) { |
551a1266 BG |
668 | dev_err(dev, |
669 | "invalid device data - cannot have both AT24_FLAG_SERIAL & AT24_FLAG_MAC."); | |
670 | return -EINVAL; | |
671 | } | |
672 | ||
eef69398 | 673 | regmap_config.val_bits = 8; |
4fa882c9 | 674 | regmap_config.reg_bits = (flags & AT24_FLAG_ADDR16) ? 16 : 8; |
d154316d | 675 | regmap_config.disable_locking = true; |
5c015258 | 676 | |
551a1266 BG |
677 | regmap = devm_regmap_init_i2c(client, ®map_config); |
678 | if (IS_ERR(regmap)) | |
679 | return PTR_ERR(regmap); | |
680 | ||
92e17647 | 681 | at24 = devm_kzalloc(dev, struct_size(at24, client_regmaps, num_addresses), |
9ae9d9bf | 682 | GFP_KERNEL); |
f0ac2363 NB |
683 | if (!at24) |
684 | return -ENOMEM; | |
2b7a5056 WS |
685 | |
686 | mutex_init(&at24->lock); | |
4fa882c9 BG |
687 | at24->byte_len = byte_len; |
688 | at24->page_size = page_size; | |
689 | at24->flags = flags; | |
a4423ced | 690 | at24->read_post = cdata->read_post; |
d08aea21 | 691 | at24->bank_addr_shift = cdata->bank_addr_shift; |
2b7a5056 | 692 | at24->num_addresses = num_addresses; |
4fa882c9 | 693 | at24->offset_adj = at24_get_offset_adj(flags, byte_len); |
92e17647 | 694 | at24->client_regmaps[0] = regmap; |
2b7a5056 | 695 | |
cd5676db BH |
696 | at24->vcc_reg = devm_regulator_get(dev, "vcc"); |
697 | if (IS_ERR(at24->vcc_reg)) | |
698 | return PTR_ERR(at24->vcc_reg); | |
6ce261e8 | 699 | |
4fa882c9 | 700 | writable = !(flags & AT24_FLAG_READONLY); |
2b7a5056 | 701 | if (writable) { |
ec3c2d51 | 702 | at24->write_max = min_t(unsigned int, |
4fa882c9 | 703 | page_size, at24_io_limit); |
34d43faf | 704 | if (!i2c_fn_i2c && at24->write_max > I2C_SMBUS_BLOCK_MAX) |
a23727cb | 705 | at24->write_max = I2C_SMBUS_BLOCK_MAX; |
2b7a5056 WS |
706 | } |
707 | ||
2b7a5056 WS |
708 | /* use dummy devices for multiple-address chips */ |
709 | for (i = 1; i < num_addresses; i++) { | |
92e17647 | 710 | err = at24_make_dummy_client(at24, i, client, ®map_config); |
e7308628 | 711 | if (err) |
73b0d922 | 712 | return err; |
2b7a5056 WS |
713 | } |
714 | ||
61f764c3 | 715 | /* |
c36748ac JG |
716 | * We initialize nvmem_config.id to NVMEM_DEVID_AUTO even if the |
717 | * label property is set as some platform can have multiple eeproms | |
718 | * with same label and we can not register each of those with same | |
719 | * label. Failing to register those eeproms trigger cascade failure | |
720 | * on such platform. | |
61f764c3 | 721 | */ |
c36748ac JG |
722 | nvmem_config.id = NVMEM_DEVID_AUTO; |
723 | ||
61f764c3 | 724 | if (device_property_present(dev, "label")) { |
61f764c3 JH |
725 | err = device_property_read_string(dev, "label", |
726 | &nvmem_config.name); | |
727 | if (err) | |
728 | return err; | |
729 | } else { | |
61f764c3 JH |
730 | nvmem_config.name = dev_name(dev); |
731 | } | |
732 | ||
774b9f43 | 733 | nvmem_config.type = NVMEM_TYPE_EEPROM; |
021c7d7b | 734 | nvmem_config.dev = dev; |
8cdc4e7e | 735 | nvmem_config.read_only = !writable; |
25e5ef30 | 736 | nvmem_config.root_only = !(flags & AT24_FLAG_IRUGO); |
8cdc4e7e BG |
737 | nvmem_config.owner = THIS_MODULE; |
738 | nvmem_config.compat = true; | |
021c7d7b | 739 | nvmem_config.base_dev = dev; |
8cdc4e7e BG |
740 | nvmem_config.reg_read = at24_read; |
741 | nvmem_config.reg_write = at24_write; | |
742 | nvmem_config.priv = at24; | |
743 | nvmem_config.stride = 1; | |
744 | nvmem_config.word_size = 1; | |
4fa882c9 | 745 | nvmem_config.size = byte_len; |
8cdc4e7e | 746 | |
b20eb4c1 BG |
747 | i2c_set_clientdata(client, at24); |
748 | ||
1e96078e SA |
749 | full_power = acpi_dev_state_d0(&client->dev); |
750 | if (full_power) { | |
751 | err = regulator_enable(at24->vcc_reg); | |
752 | if (err) { | |
753 | dev_err(dev, "Failed to enable vcc regulator\n"); | |
754 | return err; | |
755 | } | |
cd5676db | 756 | |
1e96078e SA |
757 | pm_runtime_set_active(dev); |
758 | } | |
b20eb4c1 BG |
759 | pm_runtime_enable(dev); |
760 | ||
761 | /* | |
1e96078e SA |
762 | * Perform a one-byte test read to verify that the chip is functional, |
763 | * unless powering on the device is to be avoided during probe (i.e. | |
764 | * it's powered off right now). | |
b20eb4c1 | 765 | */ |
1e96078e SA |
766 | if (full_power) { |
767 | err = at24_read(at24, 0, &test_byte, 1); | |
768 | if (err) { | |
769 | pm_runtime_disable(dev); | |
770 | if (!pm_runtime_status_suspended(dev)) | |
771 | regulator_disable(at24->vcc_reg); | |
772 | return -ENODEV; | |
773 | } | |
57d15550 | 774 | } |
2b7a5056 | 775 | |
f42c9702 DO |
776 | at24->nvmem = devm_nvmem_register(dev, &nvmem_config); |
777 | if (IS_ERR(at24->nvmem)) { | |
778 | pm_runtime_disable(dev); | |
779 | if (!pm_runtime_status_suspended(dev)) | |
780 | regulator_disable(at24->vcc_reg); | |
781 | return dev_err_probe(dev, PTR_ERR(at24->nvmem), | |
782 | "failed to register nvmem\n"); | |
783 | } | |
784 | ||
caba40ec HK |
785 | /* If this a SPD EEPROM, probe for DDR3 thermal sensor */ |
786 | if (cdata == &at24_data_spd) | |
787 | at24_probe_temp_sensor(client); | |
788 | ||
58d6fee5 MA |
789 | pm_runtime_idle(dev); |
790 | ||
285be87c JD |
791 | if (writable) |
792 | dev_info(dev, "%u byte %s EEPROM, writable, %u bytes/write\n", | |
793 | byte_len, client->name, at24->write_max); | |
794 | else | |
795 | dev_info(dev, "%u byte %s EEPROM, read-only\n", | |
796 | byte_len, client->name); | |
2b7a5056 WS |
797 | |
798 | return 0; | |
2b7a5056 WS |
799 | } |
800 | ||
ed5c2f5f | 801 | static void at24_remove(struct i2c_client *client) |
2b7a5056 | 802 | { |
cd5676db BH |
803 | struct at24_data *at24 = i2c_get_clientdata(client); |
804 | ||
98e82010 | 805 | pm_runtime_disable(&client->dev); |
1e96078e SA |
806 | if (acpi_dev_state_d0(&client->dev)) { |
807 | if (!pm_runtime_status_suspended(&client->dev)) | |
808 | regulator_disable(at24->vcc_reg); | |
809 | pm_runtime_set_suspended(&client->dev); | |
810 | } | |
2b7a5056 WS |
811 | } |
812 | ||
cd5676db BH |
813 | static int __maybe_unused at24_suspend(struct device *dev) |
814 | { | |
815 | struct i2c_client *client = to_i2c_client(dev); | |
816 | struct at24_data *at24 = i2c_get_clientdata(client); | |
817 | ||
818 | return regulator_disable(at24->vcc_reg); | |
819 | } | |
820 | ||
821 | static int __maybe_unused at24_resume(struct device *dev) | |
822 | { | |
823 | struct i2c_client *client = to_i2c_client(dev); | |
824 | struct at24_data *at24 = i2c_get_clientdata(client); | |
825 | ||
826 | return regulator_enable(at24->vcc_reg); | |
827 | } | |
828 | ||
829 | static const struct dev_pm_ops at24_pm_ops = { | |
830 | SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, | |
831 | pm_runtime_force_resume) | |
832 | SET_RUNTIME_PM_OPS(at24_suspend, at24_resume, NULL) | |
833 | }; | |
834 | ||
2b7a5056 WS |
835 | static struct i2c_driver at24_driver = { |
836 | .driver = { | |
837 | .name = "at24", | |
cd5676db | 838 | .pm = &at24_pm_ops, |
2b0eee4f | 839 | .of_match_table = of_match_ptr(at24_of_match), |
40d8edc9 | 840 | .acpi_match_table = ACPI_PTR(at24_acpi_ids), |
2b7a5056 | 841 | }, |
f050bb8f | 842 | .probe = at24_probe, |
2d6bed9c | 843 | .remove = at24_remove, |
2b7a5056 | 844 | .id_table = at24_ids, |
1e96078e | 845 | .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE, |
2b7a5056 WS |
846 | }; |
847 | ||
848 | static int __init at24_init(void) | |
849 | { | |
ec3c2d51 BG |
850 | if (!at24_io_limit) { |
851 | pr_err("at24: at24_io_limit must not be 0!\n"); | |
45efe847 WS |
852 | return -EINVAL; |
853 | } | |
854 | ||
ec3c2d51 | 855 | at24_io_limit = rounddown_pow_of_two(at24_io_limit); |
2b7a5056 WS |
856 | return i2c_add_driver(&at24_driver); |
857 | } | |
858 | module_init(at24_init); | |
859 | ||
860 | static void __exit at24_exit(void) | |
861 | { | |
862 | i2c_del_driver(&at24_driver); | |
863 | } | |
864 | module_exit(at24_exit); | |
865 | ||
866 | MODULE_DESCRIPTION("Driver for most I2C EEPROMs"); | |
867 | MODULE_AUTHOR("David Brownell and Wolfram Sang"); | |
868 | MODULE_LICENSE("GPL"); |