1567ec716SBartosz Golaszewski // SPDX-License-Identifier: GPL-2.0-or-later 25195e509SWolfram Sang /* 35195e509SWolfram Sang * at24.c - handle most I2C EEPROMs 45195e509SWolfram Sang * 55195e509SWolfram Sang * Copyright (C) 2005-2007 David Brownell 65195e509SWolfram Sang * Copyright (C) 2008 Wolfram Sang, Pengutronix 75195e509SWolfram Sang */ 84ac0d3fbSBartosz Golaszewski 940d8edc9SAndy Shevchenko #include <linux/acpi.h> 1069afc4b6SBartosz Golaszewski #include <linux/bitops.h> 11a4423cedSJean Delvare #include <linux/capability.h> 1269afc4b6SBartosz Golaszewski #include <linux/delay.h> 1369afc4b6SBartosz Golaszewski #include <linux/i2c.h> 1469afc4b6SBartosz Golaszewski #include <linux/init.h> 1569afc4b6SBartosz Golaszewski #include <linux/jiffies.h> 1669afc4b6SBartosz Golaszewski #include <linux/kernel.h> 1769afc4b6SBartosz Golaszewski #include <linux/mod_devicetable.h> 1869afc4b6SBartosz Golaszewski #include <linux/module.h> 1969afc4b6SBartosz Golaszewski #include <linux/mutex.h> 2069afc4b6SBartosz Golaszewski #include <linux/nvmem-provider.h> 2169afc4b6SBartosz Golaszewski #include <linux/of_device.h> 2269afc4b6SBartosz Golaszewski #include <linux/pm_runtime.h> 2369afc4b6SBartosz Golaszewski #include <linux/property.h> 2469afc4b6SBartosz Golaszewski #include <linux/regmap.h> 25cd5676dbSBibby Hsieh #include <linux/regulator/consumer.h> 2669afc4b6SBartosz Golaszewski #include <linux/slab.h> 275195e509SWolfram Sang 284fa882c9SBartosz Golaszewski /* Address pointer is 16 bit. */ 294fa882c9SBartosz Golaszewski #define AT24_FLAG_ADDR16 BIT(7) 304fa882c9SBartosz Golaszewski /* sysfs-entry will be read-only. */ 314fa882c9SBartosz Golaszewski #define AT24_FLAG_READONLY BIT(6) 324fa882c9SBartosz Golaszewski /* sysfs-entry will be world-readable. */ 334fa882c9SBartosz Golaszewski #define AT24_FLAG_IRUGO BIT(5) 344fa882c9SBartosz Golaszewski /* Take always 8 addresses (24c00). */ 354fa882c9SBartosz Golaszewski #define AT24_FLAG_TAKE8ADDR BIT(4) 364fa882c9SBartosz Golaszewski /* Factory-programmed serial number. */ 374fa882c9SBartosz Golaszewski #define AT24_FLAG_SERIAL BIT(3) 384fa882c9SBartosz Golaszewski /* Factory-programmed mac address. */ 394fa882c9SBartosz Golaszewski #define AT24_FLAG_MAC BIT(2) 404fa882c9SBartosz Golaszewski /* Does not auto-rollover reads to the next slave address. */ 414fa882c9SBartosz Golaszewski #define AT24_FLAG_NO_RDROL BIT(1) 424fa882c9SBartosz Golaszewski 435195e509SWolfram Sang /* 445195e509SWolfram Sang * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable. 455195e509SWolfram Sang * Differences between different vendor product lines (like Atmel AT24C or 465195e509SWolfram Sang * MicroChip 24LC, etc) won't much matter for typical read/write access. 475195e509SWolfram Sang * There are also I2C RAM chips, likewise interchangeable. One example 485195e509SWolfram Sang * would be the PCF8570, which acts like a 24c02 EEPROM (256 bytes). 495195e509SWolfram Sang * 505195e509SWolfram Sang * However, misconfiguration can lose data. "Set 16-bit memory address" 515195e509SWolfram Sang * to a part with 8-bit addressing will overwrite data. Writing with too 525195e509SWolfram Sang * big a page size also loses data. And it's not safe to assume that the 535195e509SWolfram Sang * conventional addresses 0x50..0x57 only hold eeproms; a PCF8563 RTC 545195e509SWolfram Sang * uses 0x51, for just one example. 555195e509SWolfram Sang * 565195e509SWolfram Sang * Accordingly, explicit board-specific configuration data should be used 575195e509SWolfram Sang * in almost all cases. (One partial exception is an SMBus used to access 585195e509SWolfram Sang * "SPD" data for DRAM sticks. Those only use 24c02 EEPROMs.) 595195e509SWolfram Sang * 605195e509SWolfram Sang * So this driver uses "new style" I2C driver binding, expecting to be 615195e509SWolfram Sang * told what devices exist. That may be in arch/X/mach-Y/board-Z.c or 625195e509SWolfram Sang * similar kernel-resident tables; or, configuration data coming from 635195e509SWolfram Sang * a bootloader. 645195e509SWolfram Sang * 655195e509SWolfram Sang * Other than binding model, current differences from "eeprom" driver are 665195e509SWolfram Sang * that this one handles write access and isn't restricted to 24c02 devices. 675195e509SWolfram Sang * It also handles larger devices (32 kbit and up) with two-byte addresses, 685195e509SWolfram Sang * which won't work on pure SMBus systems. 695195e509SWolfram Sang */ 705195e509SWolfram Sang 715195e509SWolfram Sang struct at24_data { 725195e509SWolfram Sang /* 735195e509SWolfram Sang * Lock protects against activities from other Linux tasks, 745195e509SWolfram Sang * but not from changes by other I2C masters. 755195e509SWolfram Sang */ 765195e509SWolfram Sang struct mutex lock; 775195e509SWolfram Sang 78aa4ce228SBartosz Golaszewski unsigned int write_max; 79aa4ce228SBartosz Golaszewski unsigned int num_addresses; 804bb5c13cSHeiner Kallweit unsigned int offset_adj; 815195e509SWolfram Sang 827c280664SBartosz Golaszewski u32 byte_len; 837c280664SBartosz Golaszewski u16 page_size; 847c280664SBartosz Golaszewski u8 flags; 857c280664SBartosz Golaszewski 8657d15550SAndrew Lunn struct nvmem_device *nvmem; 87cd5676dbSBibby Hsieh struct regulator *vcc_reg; 88a4423cedSJean Delvare void (*read_post)(unsigned int off, char *buf, size_t count); 8957d15550SAndrew Lunn 905195e509SWolfram Sang /* 915195e509SWolfram Sang * Some chips tie up multiple I2C addresses; dummy devices reserve 9292e17647SHeiner Kallweit * them for us. 935195e509SWolfram Sang */ 94d08aea21SMaxim Kochetkov u8 bank_addr_shift; 9592e17647SHeiner Kallweit struct regmap *client_regmaps[]; 965195e509SWolfram Sang }; 975195e509SWolfram Sang 985195e509SWolfram Sang /* 995195e509SWolfram Sang * This parameter is to help this driver avoid blocking other drivers out 1005195e509SWolfram Sang * of I2C for potentially troublesome amounts of time. With a 100 kHz I2C 1015195e509SWolfram Sang * clock, one 256 byte read takes about 1/43 second which is excessive; 1025195e509SWolfram Sang * but the 1/170 second it takes at 400 kHz may be quite reasonable; and 1035195e509SWolfram Sang * at 1 MHz (Fm+) a 1/430 second delay could easily be invisible. 1045195e509SWolfram Sang * 1055195e509SWolfram Sang * This value is forced to be a power of two so that writes align on pages. 1065195e509SWolfram Sang */ 107ec3c2d51SBartosz Golaszewski static unsigned int at24_io_limit = 128; 108ec3c2d51SBartosz Golaszewski module_param_named(io_limit, at24_io_limit, uint, 0); 109ec3c2d51SBartosz Golaszewski MODULE_PARM_DESC(at24_io_limit, "Maximum bytes per I/O (default 128)"); 1105195e509SWolfram Sang 1115195e509SWolfram Sang /* 1125195e509SWolfram Sang * Specs often allow 5 msec for a page write, sometimes 20 msec; 1135195e509SWolfram Sang * it's important to recover from write timeouts. 1145195e509SWolfram Sang */ 115ec3c2d51SBartosz Golaszewski static unsigned int at24_write_timeout = 25; 116ec3c2d51SBartosz Golaszewski module_param_named(write_timeout, at24_write_timeout, uint, 0); 117ec3c2d51SBartosz Golaszewski MODULE_PARM_DESC(at24_write_timeout, "Time (in ms) to try writes (default 25)"); 1185195e509SWolfram Sang 119b680f4faSSven Van Asbroeck struct at24_chip_data { 120b680f4faSSven Van Asbroeck u32 byte_len; 121b680f4faSSven Van Asbroeck u8 flags; 122d08aea21SMaxim Kochetkov u8 bank_addr_shift; 123a4423cedSJean Delvare void (*read_post)(unsigned int off, char *buf, size_t count); 124b680f4faSSven Van Asbroeck }; 125b680f4faSSven Van Asbroeck 126b680f4faSSven Van Asbroeck #define AT24_CHIP_DATA(_name, _len, _flags) \ 127b680f4faSSven Van Asbroeck static const struct at24_chip_data _name = { \ 128b680f4faSSven Van Asbroeck .byte_len = _len, .flags = _flags, \ 129b680f4faSSven Van Asbroeck } 130b680f4faSSven Van Asbroeck 131a4423cedSJean Delvare #define AT24_CHIP_DATA_CB(_name, _len, _flags, _read_post) \ 132a4423cedSJean Delvare static const struct at24_chip_data _name = { \ 133a4423cedSJean Delvare .byte_len = _len, .flags = _flags, \ 134a4423cedSJean Delvare .read_post = _read_post, \ 135a4423cedSJean Delvare } 136a4423cedSJean Delvare 137d08aea21SMaxim Kochetkov #define AT24_CHIP_DATA_BS(_name, _len, _flags, _bank_addr_shift) \ 138d08aea21SMaxim Kochetkov static const struct at24_chip_data _name = { \ 139d08aea21SMaxim Kochetkov .byte_len = _len, .flags = _flags, \ 140d08aea21SMaxim Kochetkov .bank_addr_shift = _bank_addr_shift \ 141d08aea21SMaxim Kochetkov } 142d08aea21SMaxim Kochetkov 143a4423cedSJean Delvare static void at24_read_post_vaio(unsigned int off, char *buf, size_t count) 144a4423cedSJean Delvare { 145a4423cedSJean Delvare int i; 146a4423cedSJean Delvare 147a4423cedSJean Delvare if (capable(CAP_SYS_ADMIN)) 148a4423cedSJean Delvare return; 149a4423cedSJean Delvare 150a4423cedSJean Delvare /* 151a4423cedSJean Delvare * Hide VAIO private settings to regular users: 152a4423cedSJean Delvare * - BIOS passwords: bytes 0x00 to 0x0f 153a4423cedSJean Delvare * - UUID: bytes 0x10 to 0x1f 154a4423cedSJean Delvare * - Serial number: 0xc0 to 0xdf 155a4423cedSJean Delvare */ 156a4423cedSJean Delvare for (i = 0; i < count; i++) { 157a4423cedSJean Delvare if ((off + i <= 0x1f) || 158a4423cedSJean Delvare (off + i >= 0xc0 && off + i <= 0xdf)) 159a4423cedSJean Delvare buf[i] = 0; 160a4423cedSJean Delvare } 161a4423cedSJean Delvare } 162a4423cedSJean Delvare 1635195e509SWolfram Sang /* needs 8 addresses as A0-A2 are ignored */ 164b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c00, 128 / 8, AT24_FLAG_TAKE8ADDR); 1655195e509SWolfram Sang /* old variants can't be handled with this generic entry! */ 166b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c01, 1024 / 8, 0); 167b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs01, 16, 168b680f4faSSven Van Asbroeck AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 169b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c02, 2048 / 8, 0); 170b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs02, 16, 171b680f4faSSven Van Asbroeck AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 172b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24mac402, 48 / 8, 173b680f4faSSven Van Asbroeck AT24_FLAG_MAC | AT24_FLAG_READONLY); 174b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24mac602, 64 / 8, 175b680f4faSSven Van Asbroeck AT24_FLAG_MAC | AT24_FLAG_READONLY); 1765195e509SWolfram Sang /* spd is a 24c02 in memory DIMMs */ 177b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_spd, 2048 / 8, 178b680f4faSSven Van Asbroeck AT24_FLAG_READONLY | AT24_FLAG_IRUGO); 179a4423cedSJean Delvare /* 24c02_vaio is a 24c02 on some Sony laptops */ 180a4423cedSJean Delvare AT24_CHIP_DATA_CB(at24_data_24c02_vaio, 2048 / 8, 181a4423cedSJean Delvare AT24_FLAG_READONLY | AT24_FLAG_IRUGO, 182a4423cedSJean Delvare at24_read_post_vaio); 183b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c04, 4096 / 8, 0); 184b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs04, 16, 185b680f4faSSven Van Asbroeck AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 1865195e509SWolfram Sang /* 24rf08 quirk is handled at i2c-core */ 187b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c08, 8192 / 8, 0); 188b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs08, 16, 189b680f4faSSven Van Asbroeck AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 190b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c16, 16384 / 8, 0); 191b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs16, 16, 192b680f4faSSven Van Asbroeck AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 193b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c32, 32768 / 8, AT24_FLAG_ADDR16); 194b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs32, 16, 195b680f4faSSven Van Asbroeck AT24_FLAG_ADDR16 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 196b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c64, 65536 / 8, AT24_FLAG_ADDR16); 197b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs64, 16, 198b680f4faSSven Van Asbroeck AT24_FLAG_ADDR16 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 199b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c128, 131072 / 8, AT24_FLAG_ADDR16); 200b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c256, 262144 / 8, AT24_FLAG_ADDR16); 201b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c512, 524288 / 8, AT24_FLAG_ADDR16); 202b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c1024, 1048576 / 8, AT24_FLAG_ADDR16); 203d08aea21SMaxim Kochetkov AT24_CHIP_DATA_BS(at24_data_24c1025, 1048576 / 8, AT24_FLAG_ADDR16, 2); 20437cf28d3SAdrian Bunk AT24_CHIP_DATA(at24_data_24c2048, 2097152 / 8, AT24_FLAG_ADDR16); 205b680f4faSSven Van Asbroeck /* identical to 24c08 ? */ 206b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_INT3499, 8192 / 8, 0); 207b680f4faSSven Van Asbroeck 208b680f4faSSven Van Asbroeck static const struct i2c_device_id at24_ids[] = { 209b680f4faSSven Van Asbroeck { "24c00", (kernel_ulong_t)&at24_data_24c00 }, 210b680f4faSSven Van Asbroeck { "24c01", (kernel_ulong_t)&at24_data_24c01 }, 211b680f4faSSven Van Asbroeck { "24cs01", (kernel_ulong_t)&at24_data_24cs01 }, 212b680f4faSSven Van Asbroeck { "24c02", (kernel_ulong_t)&at24_data_24c02 }, 213b680f4faSSven Van Asbroeck { "24cs02", (kernel_ulong_t)&at24_data_24cs02 }, 214b680f4faSSven Van Asbroeck { "24mac402", (kernel_ulong_t)&at24_data_24mac402 }, 215b680f4faSSven Van Asbroeck { "24mac602", (kernel_ulong_t)&at24_data_24mac602 }, 216b680f4faSSven Van Asbroeck { "spd", (kernel_ulong_t)&at24_data_spd }, 217a4423cedSJean Delvare { "24c02-vaio", (kernel_ulong_t)&at24_data_24c02_vaio }, 218b680f4faSSven Van Asbroeck { "24c04", (kernel_ulong_t)&at24_data_24c04 }, 219b680f4faSSven Van Asbroeck { "24cs04", (kernel_ulong_t)&at24_data_24cs04 }, 220b680f4faSSven Van Asbroeck { "24c08", (kernel_ulong_t)&at24_data_24c08 }, 221b680f4faSSven Van Asbroeck { "24cs08", (kernel_ulong_t)&at24_data_24cs08 }, 222b680f4faSSven Van Asbroeck { "24c16", (kernel_ulong_t)&at24_data_24c16 }, 223b680f4faSSven Van Asbroeck { "24cs16", (kernel_ulong_t)&at24_data_24cs16 }, 224b680f4faSSven Van Asbroeck { "24c32", (kernel_ulong_t)&at24_data_24c32 }, 225b680f4faSSven Van Asbroeck { "24cs32", (kernel_ulong_t)&at24_data_24cs32 }, 226b680f4faSSven Van Asbroeck { "24c64", (kernel_ulong_t)&at24_data_24c64 }, 227b680f4faSSven Van Asbroeck { "24cs64", (kernel_ulong_t)&at24_data_24cs64 }, 228b680f4faSSven Van Asbroeck { "24c128", (kernel_ulong_t)&at24_data_24c128 }, 229b680f4faSSven Van Asbroeck { "24c256", (kernel_ulong_t)&at24_data_24c256 }, 230b680f4faSSven Van Asbroeck { "24c512", (kernel_ulong_t)&at24_data_24c512 }, 231b680f4faSSven Van Asbroeck { "24c1024", (kernel_ulong_t)&at24_data_24c1024 }, 232d08aea21SMaxim Kochetkov { "24c1025", (kernel_ulong_t)&at24_data_24c1025 }, 23337cf28d3SAdrian Bunk { "24c2048", (kernel_ulong_t)&at24_data_24c2048 }, 2345195e509SWolfram Sang { "at24", 0 }, 2355195e509SWolfram Sang { /* END OF LIST */ } 2365195e509SWolfram Sang }; 2375195e509SWolfram Sang MODULE_DEVICE_TABLE(i2c, at24_ids); 2385195e509SWolfram Sang 2397f2a2f0dSJavier Martinez Canillas static const struct of_device_id at24_of_match[] = { 240b680f4faSSven Van Asbroeck { .compatible = "atmel,24c00", .data = &at24_data_24c00 }, 241b680f4faSSven Van Asbroeck { .compatible = "atmel,24c01", .data = &at24_data_24c01 }, 2420f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs01", .data = &at24_data_24cs01 }, 243b680f4faSSven Van Asbroeck { .compatible = "atmel,24c02", .data = &at24_data_24c02 }, 2440f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs02", .data = &at24_data_24cs02 }, 2450f30aca7SBartosz Golaszewski { .compatible = "atmel,24mac402", .data = &at24_data_24mac402 }, 2460f30aca7SBartosz Golaszewski { .compatible = "atmel,24mac602", .data = &at24_data_24mac602 }, 247b680f4faSSven Van Asbroeck { .compatible = "atmel,spd", .data = &at24_data_spd }, 248b680f4faSSven Van Asbroeck { .compatible = "atmel,24c04", .data = &at24_data_24c04 }, 2490f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs04", .data = &at24_data_24cs04 }, 250b680f4faSSven Van Asbroeck { .compatible = "atmel,24c08", .data = &at24_data_24c08 }, 2510f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs08", .data = &at24_data_24cs08 }, 252b680f4faSSven Van Asbroeck { .compatible = "atmel,24c16", .data = &at24_data_24c16 }, 2530f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs16", .data = &at24_data_24cs16 }, 254b680f4faSSven Van Asbroeck { .compatible = "atmel,24c32", .data = &at24_data_24c32 }, 2550f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs32", .data = &at24_data_24cs32 }, 256b680f4faSSven Van Asbroeck { .compatible = "atmel,24c64", .data = &at24_data_24c64 }, 2570f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs64", .data = &at24_data_24cs64 }, 258b680f4faSSven Van Asbroeck { .compatible = "atmel,24c128", .data = &at24_data_24c128 }, 259b680f4faSSven Van Asbroeck { .compatible = "atmel,24c256", .data = &at24_data_24c256 }, 260b680f4faSSven Van Asbroeck { .compatible = "atmel,24c512", .data = &at24_data_24c512 }, 261b680f4faSSven Van Asbroeck { .compatible = "atmel,24c1024", .data = &at24_data_24c1024 }, 262d08aea21SMaxim Kochetkov { .compatible = "atmel,24c1025", .data = &at24_data_24c1025 }, 26337cf28d3SAdrian Bunk { .compatible = "atmel,24c2048", .data = &at24_data_24c2048 }, 264b680f4faSSven Van Asbroeck { /* END OF LIST */ }, 2657f2a2f0dSJavier Martinez Canillas }; 2667f2a2f0dSJavier Martinez Canillas MODULE_DEVICE_TABLE(of, at24_of_match); 2677f2a2f0dSJavier Martinez Canillas 2688965930cSLee Jones static const struct acpi_device_id __maybe_unused at24_acpi_ids[] = { 269b680f4faSSven Van Asbroeck { "INT3499", (kernel_ulong_t)&at24_data_INT3499 }, 2704837621cSMarkus Pietrek { "TPF0001", (kernel_ulong_t)&at24_data_24c1024 }, 271b680f4faSSven Van Asbroeck { /* END OF LIST */ } 27240d8edc9SAndy Shevchenko }; 27340d8edc9SAndy Shevchenko MODULE_DEVICE_TABLE(acpi, at24_acpi_ids); 27440d8edc9SAndy Shevchenko 2755195e509SWolfram Sang /* 2765195e509SWolfram Sang * This routine supports chips which consume multiple I2C addresses. It 2775195e509SWolfram Sang * computes the addressing information to be used for a given r/w request. 2785195e509SWolfram Sang * Assumes that sanity checks for offset happened at sysfs-layer. 2799afd6866SBartosz Golaszewski * 2809afd6866SBartosz Golaszewski * Slave address and byte offset derive from the offset. Always 2819afd6866SBartosz Golaszewski * set the byte address; on a multi-master board, another master 2829afd6866SBartosz Golaszewski * may have changed the chip's "current" address pointer. 2835195e509SWolfram Sang */ 28492e17647SHeiner Kallweit static struct regmap *at24_translate_offset(struct at24_data *at24, 2852da78ac3SBartosz Golaszewski unsigned int *offset) 2865195e509SWolfram Sang { 287aa4ce228SBartosz Golaszewski unsigned int i; 2885195e509SWolfram Sang 2897c280664SBartosz Golaszewski if (at24->flags & AT24_FLAG_ADDR16) { 2905195e509SWolfram Sang i = *offset >> 16; 2915195e509SWolfram Sang *offset &= 0xffff; 2925195e509SWolfram Sang } else { 2935195e509SWolfram Sang i = *offset >> 8; 2945195e509SWolfram Sang *offset &= 0xff; 2955195e509SWolfram Sang } 2965195e509SWolfram Sang 29792e17647SHeiner Kallweit return at24->client_regmaps[i]; 2985195e509SWolfram Sang } 2995195e509SWolfram Sang 300f1a640c5SBartosz Golaszewski static struct device *at24_base_client_dev(struct at24_data *at24) 301f1a640c5SBartosz Golaszewski { 30292e17647SHeiner Kallweit return regmap_get_device(at24->client_regmaps[0]); 303f1a640c5SBartosz Golaszewski } 304f1a640c5SBartosz Golaszewski 305e32213fbSSven Van Asbroeck static size_t at24_adjust_read_count(struct at24_data *at24, 306e32213fbSSven Van Asbroeck unsigned int offset, size_t count) 307e32213fbSSven Van Asbroeck { 308e32213fbSSven Van Asbroeck unsigned int bits; 309e32213fbSSven Van Asbroeck size_t remainder; 310e32213fbSSven Van Asbroeck 311e32213fbSSven Van Asbroeck /* 312e32213fbSSven Van Asbroeck * In case of multi-address chips that don't rollover reads to 313e32213fbSSven Van Asbroeck * the next slave address: truncate the count to the slave boundary, 314e32213fbSSven Van Asbroeck * so that the read never straddles slaves. 315e32213fbSSven Van Asbroeck */ 3167c280664SBartosz Golaszewski if (at24->flags & AT24_FLAG_NO_RDROL) { 3177c280664SBartosz Golaszewski bits = (at24->flags & AT24_FLAG_ADDR16) ? 16 : 8; 318e32213fbSSven Van Asbroeck remainder = BIT(bits) - offset; 319e32213fbSSven Van Asbroeck if (count > remainder) 320e32213fbSSven Van Asbroeck count = remainder; 321e32213fbSSven Van Asbroeck } 322e32213fbSSven Van Asbroeck 323ec3c2d51SBartosz Golaszewski if (count > at24_io_limit) 324ec3c2d51SBartosz Golaszewski count = at24_io_limit; 325e32213fbSSven Van Asbroeck 326e32213fbSSven Van Asbroeck return count; 327e32213fbSSven Van Asbroeck } 328e32213fbSSven Van Asbroeck 3294bb5c13cSHeiner Kallweit static ssize_t at24_regmap_read(struct at24_data *at24, char *buf, 3304bb5c13cSHeiner Kallweit unsigned int offset, size_t count) 3314bb5c13cSHeiner Kallweit { 3324bb5c13cSHeiner Kallweit unsigned long timeout, read_time; 3334bb5c13cSHeiner Kallweit struct regmap *regmap; 3344bb5c13cSHeiner Kallweit int ret; 3354bb5c13cSHeiner Kallweit 33692e17647SHeiner Kallweit regmap = at24_translate_offset(at24, &offset); 337e32213fbSSven Van Asbroeck count = at24_adjust_read_count(at24, offset, count); 3384bb5c13cSHeiner Kallweit 3394bb5c13cSHeiner Kallweit /* adjust offset for mac and serial read ops */ 3404bb5c13cSHeiner Kallweit offset += at24->offset_adj; 3414bb5c13cSHeiner Kallweit 3429a9e295eSWang Xin timeout = jiffies + msecs_to_jiffies(at24_write_timeout); 3439a9e295eSWang Xin do { 3449a9e295eSWang Xin /* 3459a9e295eSWang Xin * The timestamp shall be taken before the actual operation 3469a9e295eSWang Xin * to avoid a premature timeout in case of high CPU load. 3479a9e295eSWang Xin */ 3489a9e295eSWang Xin read_time = jiffies; 3499a9e295eSWang Xin 3504bb5c13cSHeiner Kallweit ret = regmap_bulk_read(regmap, offset, buf, count); 35192e17647SHeiner Kallweit dev_dbg(regmap_get_device(regmap), "read %zu@%d --> %d (%ld)\n", 3524bb5c13cSHeiner Kallweit count, offset, ret, jiffies); 3534bb5c13cSHeiner Kallweit if (!ret) 3544bb5c13cSHeiner Kallweit return count; 3559a9e295eSWang Xin 3569a9e295eSWang Xin usleep_range(1000, 1500); 3579a9e295eSWang Xin } while (time_before(read_time, timeout)); 3584bb5c13cSHeiner Kallweit 3594bb5c13cSHeiner Kallweit return -ETIMEDOUT; 3604bb5c13cSHeiner Kallweit } 3614bb5c13cSHeiner Kallweit 3625195e509SWolfram Sang /* 3635195e509SWolfram Sang * Note that if the hardware write-protect pin is pulled high, the whole 3645195e509SWolfram Sang * chip is normally write protected. But there are plenty of product 3655195e509SWolfram Sang * variants here, including OTP fuses and partial chip protect. 3665195e509SWolfram Sang * 367cd0c8615SBartosz Golaszewski * We only use page mode writes; the alternative is sloooow. These routines 368cd0c8615SBartosz Golaszewski * write at most one page. 3695195e509SWolfram Sang */ 370cd0c8615SBartosz Golaszewski 371cd0c8615SBartosz Golaszewski static size_t at24_adjust_write_count(struct at24_data *at24, 3722da78ac3SBartosz Golaszewski unsigned int offset, size_t count) 3735195e509SWolfram Sang { 374aa4ce228SBartosz Golaszewski unsigned int next_page; 3755195e509SWolfram Sang 3765195e509SWolfram Sang /* write_max is at most a page */ 3775195e509SWolfram Sang if (count > at24->write_max) 3785195e509SWolfram Sang count = at24->write_max; 3795195e509SWolfram Sang 3805195e509SWolfram Sang /* Never roll over backwards, to the start of this page */ 3817c280664SBartosz Golaszewski next_page = roundup(offset + 1, at24->page_size); 3825195e509SWolfram Sang if (offset + count > next_page) 3835195e509SWolfram Sang count = next_page - offset; 3845195e509SWolfram Sang 385cd0c8615SBartosz Golaszewski return count; 386cd0c8615SBartosz Golaszewski } 387cd0c8615SBartosz Golaszewski 3888e5888e1SHeiner Kallweit static ssize_t at24_regmap_write(struct at24_data *at24, const char *buf, 3898e5888e1SHeiner Kallweit unsigned int offset, size_t count) 3908e5888e1SHeiner Kallweit { 3918e5888e1SHeiner Kallweit unsigned long timeout, write_time; 3928e5888e1SHeiner Kallweit struct regmap *regmap; 3938e5888e1SHeiner Kallweit int ret; 3948e5888e1SHeiner Kallweit 39592e17647SHeiner Kallweit regmap = at24_translate_offset(at24, &offset); 3968e5888e1SHeiner Kallweit count = at24_adjust_write_count(at24, offset, count); 3979a9e295eSWang Xin timeout = jiffies + msecs_to_jiffies(at24_write_timeout); 3988e5888e1SHeiner Kallweit 3999a9e295eSWang Xin do { 4009a9e295eSWang Xin /* 4019a9e295eSWang Xin * The timestamp shall be taken before the actual operation 4029a9e295eSWang Xin * to avoid a premature timeout in case of high CPU load. 4039a9e295eSWang Xin */ 4049a9e295eSWang Xin write_time = jiffies; 4059a9e295eSWang Xin 4068e5888e1SHeiner Kallweit ret = regmap_bulk_write(regmap, offset, buf, count); 40792e17647SHeiner Kallweit dev_dbg(regmap_get_device(regmap), "write %zu@%d --> %d (%ld)\n", 4088e5888e1SHeiner Kallweit count, offset, ret, jiffies); 4098e5888e1SHeiner Kallweit if (!ret) 4108e5888e1SHeiner Kallweit return count; 4119a9e295eSWang Xin 4129a9e295eSWang Xin usleep_range(1000, 1500); 4139a9e295eSWang Xin } while (time_before(write_time, timeout)); 4148e5888e1SHeiner Kallweit 4158e5888e1SHeiner Kallweit return -ETIMEDOUT; 4168e5888e1SHeiner Kallweit } 4178e5888e1SHeiner Kallweit 418d5bc0047SBartosz Golaszewski static int at24_read(void *priv, unsigned int off, void *val, size_t count) 419d5bc0047SBartosz Golaszewski { 4205ca2b5b7SBartosz Golaszewski struct at24_data *at24; 4215ca2b5b7SBartosz Golaszewski struct device *dev; 422d5bc0047SBartosz Golaszewski char *buf = val; 42399363d1cSJean Delvare int i, ret; 424d5bc0047SBartosz Golaszewski 4255ca2b5b7SBartosz Golaszewski at24 = priv; 426f1a640c5SBartosz Golaszewski dev = at24_base_client_dev(at24); 4275ca2b5b7SBartosz Golaszewski 428d5bc0047SBartosz Golaszewski if (unlikely(!count)) 429d5bc0047SBartosz Golaszewski return count; 430d5bc0047SBartosz Golaszewski 4317c280664SBartosz Golaszewski if (off + count > at24->byte_len) 432d9bcd462SHeiner Kallweit return -EINVAL; 433d9bcd462SHeiner Kallweit 434f9ecc83fSSakari Ailus ret = pm_runtime_get_sync(dev); 43598e82010SDivagar Mohandass if (ret < 0) { 436f9ecc83fSSakari Ailus pm_runtime_put_noidle(dev); 43798e82010SDivagar Mohandass return ret; 43898e82010SDivagar Mohandass } 43998e82010SDivagar Mohandass 440d5bc0047SBartosz Golaszewski /* 441d5bc0047SBartosz Golaszewski * Read data from chip, protecting against concurrent updates 442d5bc0047SBartosz Golaszewski * from this host, but not from other I2C masters. 443d5bc0047SBartosz Golaszewski */ 444d5bc0047SBartosz Golaszewski mutex_lock(&at24->lock); 445d5bc0047SBartosz Golaszewski 44699363d1cSJean Delvare for (i = 0; count; i += ret, count -= ret) { 44799363d1cSJean Delvare ret = at24_regmap_read(at24, buf + i, off + i, count); 448eb27fde2SBartosz Golaszewski if (ret < 0) { 449d5bc0047SBartosz Golaszewski mutex_unlock(&at24->lock); 450f9ecc83fSSakari Ailus pm_runtime_put(dev); 451eb27fde2SBartosz Golaszewski return ret; 452d5bc0047SBartosz Golaszewski } 453d5bc0047SBartosz Golaszewski } 454d5bc0047SBartosz Golaszewski 455d5bc0047SBartosz Golaszewski mutex_unlock(&at24->lock); 456d5bc0047SBartosz Golaszewski 457f9ecc83fSSakari Ailus pm_runtime_put(dev); 45898e82010SDivagar Mohandass 459a4423cedSJean Delvare if (unlikely(at24->read_post)) 46099363d1cSJean Delvare at24->read_post(off, buf, i); 461a4423cedSJean Delvare 462d5bc0047SBartosz Golaszewski return 0; 463d5bc0047SBartosz Golaszewski } 464d5bc0047SBartosz Golaszewski 465cf0361a2SSrinivas Kandagatla static int at24_write(void *priv, unsigned int off, void *val, size_t count) 4665195e509SWolfram Sang { 4675ca2b5b7SBartosz Golaszewski struct at24_data *at24; 4685ca2b5b7SBartosz Golaszewski struct device *dev; 469cf0361a2SSrinivas Kandagatla char *buf = val; 47098e82010SDivagar Mohandass int ret; 4715195e509SWolfram Sang 4725ca2b5b7SBartosz Golaszewski at24 = priv; 473f1a640c5SBartosz Golaszewski dev = at24_base_client_dev(at24); 4745ca2b5b7SBartosz Golaszewski 4755195e509SWolfram Sang if (unlikely(!count)) 476cf0361a2SSrinivas Kandagatla return -EINVAL; 4775195e509SWolfram Sang 4787c280664SBartosz Golaszewski if (off + count > at24->byte_len) 479d9bcd462SHeiner Kallweit return -EINVAL; 480d9bcd462SHeiner Kallweit 481f9ecc83fSSakari Ailus ret = pm_runtime_get_sync(dev); 48298e82010SDivagar Mohandass if (ret < 0) { 483f9ecc83fSSakari Ailus pm_runtime_put_noidle(dev); 48498e82010SDivagar Mohandass return ret; 48598e82010SDivagar Mohandass } 48698e82010SDivagar Mohandass 4875195e509SWolfram Sang /* 4885195e509SWolfram Sang * Write data to chip, protecting against concurrent updates 4895195e509SWolfram Sang * from this host, but not from other I2C masters. 4905195e509SWolfram Sang */ 4915195e509SWolfram Sang mutex_lock(&at24->lock); 4925195e509SWolfram Sang 4935195e509SWolfram Sang while (count) { 494c4fee330SBartosz Golaszewski ret = at24_regmap_write(at24, buf, off, count); 495c4fee330SBartosz Golaszewski if (ret < 0) { 496cf0361a2SSrinivas Kandagatla mutex_unlock(&at24->lock); 497f9ecc83fSSakari Ailus pm_runtime_put(dev); 498c4fee330SBartosz Golaszewski return ret; 4995195e509SWolfram Sang } 500c4fee330SBartosz Golaszewski buf += ret; 501c4fee330SBartosz Golaszewski off += ret; 502c4fee330SBartosz Golaszewski count -= ret; 5035195e509SWolfram Sang } 5045195e509SWolfram Sang 5055195e509SWolfram Sang mutex_unlock(&at24->lock); 5065195e509SWolfram Sang 507f9ecc83fSSakari Ailus pm_runtime_put(dev); 50898e82010SDivagar Mohandass 50957d15550SAndrew Lunn return 0; 51057d15550SAndrew Lunn } 51157d15550SAndrew Lunn 5124fa882c9SBartosz Golaszewski static const struct at24_chip_data *at24_get_chip_data(struct device *dev) 513feb2f19bSBartosz Golaszewski { 514feb2f19bSBartosz Golaszewski struct device_node *of_node = dev->of_node; 515feb2f19bSBartosz Golaszewski const struct at24_chip_data *cdata; 516feb2f19bSBartosz Golaszewski const struct i2c_device_id *id; 517feb2f19bSBartosz Golaszewski 518feb2f19bSBartosz Golaszewski id = i2c_match_id(at24_ids, to_i2c_client(dev)); 519feb2f19bSBartosz Golaszewski 520feb2f19bSBartosz Golaszewski /* 521feb2f19bSBartosz Golaszewski * The I2C core allows OF nodes compatibles to match against the 522feb2f19bSBartosz Golaszewski * I2C device ID table as a fallback, so check not only if an OF 523feb2f19bSBartosz Golaszewski * node is present but also if it matches an OF device ID entry. 524feb2f19bSBartosz Golaszewski */ 525feb2f19bSBartosz Golaszewski if (of_node && of_match_device(at24_of_match, dev)) 526feb2f19bSBartosz Golaszewski cdata = of_device_get_match_data(dev); 527feb2f19bSBartosz Golaszewski else if (id) 5285fa4d14eSBartosz Golaszewski cdata = (void *)id->driver_data; 529feb2f19bSBartosz Golaszewski else 530feb2f19bSBartosz Golaszewski cdata = acpi_device_get_match_data(dev); 531feb2f19bSBartosz Golaszewski 532feb2f19bSBartosz Golaszewski if (!cdata) 5334fa882c9SBartosz Golaszewski return ERR_PTR(-ENODEV); 534feb2f19bSBartosz Golaszewski 5354fa882c9SBartosz Golaszewski return cdata; 536feb2f19bSBartosz Golaszewski } 537feb2f19bSBartosz Golaszewski 53873b0d922SBartosz Golaszewski static int at24_make_dummy_client(struct at24_data *at24, unsigned int index, 53992e17647SHeiner Kallweit struct i2c_client *base_client, 54073b0d922SBartosz Golaszewski struct regmap_config *regmap_config) 54173b0d922SBartosz Golaszewski { 54292e17647SHeiner Kallweit struct i2c_client *dummy_client; 54373b0d922SBartosz Golaszewski struct regmap *regmap; 54473b0d922SBartosz Golaszewski 54592e17647SHeiner Kallweit dummy_client = devm_i2c_new_dummy_device(&base_client->dev, 54692e17647SHeiner Kallweit base_client->adapter, 547d08aea21SMaxim Kochetkov base_client->addr + 548d08aea21SMaxim Kochetkov (index << at24->bank_addr_shift)); 549e7308628SBartosz Golaszewski if (IS_ERR(dummy_client)) 550e7308628SBartosz Golaszewski return PTR_ERR(dummy_client); 55173b0d922SBartosz Golaszewski 55273b0d922SBartosz Golaszewski regmap = devm_regmap_init_i2c(dummy_client, regmap_config); 553e7308628SBartosz Golaszewski if (IS_ERR(regmap)) 55473b0d922SBartosz Golaszewski return PTR_ERR(regmap); 55573b0d922SBartosz Golaszewski 55692e17647SHeiner Kallweit at24->client_regmaps[index] = regmap; 55773b0d922SBartosz Golaszewski 55873b0d922SBartosz Golaszewski return 0; 55973b0d922SBartosz Golaszewski } 56073b0d922SBartosz Golaszewski 5614bb5c13cSHeiner Kallweit static unsigned int at24_get_offset_adj(u8 flags, unsigned int byte_len) 5624bb5c13cSHeiner Kallweit { 5634bb5c13cSHeiner Kallweit if (flags & AT24_FLAG_MAC) { 5644bb5c13cSHeiner Kallweit /* EUI-48 starts from 0x9a, EUI-64 from 0x98 */ 5654bb5c13cSHeiner Kallweit return 0xa0 - byte_len; 5664bb5c13cSHeiner Kallweit } else if (flags & AT24_FLAG_SERIAL && flags & AT24_FLAG_ADDR16) { 5674bb5c13cSHeiner Kallweit /* 5684bb5c13cSHeiner Kallweit * For 16 bit address pointers, the word address must contain 5694bb5c13cSHeiner Kallweit * a '10' sequence in bits 11 and 10 regardless of the 5704bb5c13cSHeiner Kallweit * intended position of the address pointer. 5714bb5c13cSHeiner Kallweit */ 5724bb5c13cSHeiner Kallweit return 0x0800; 5734bb5c13cSHeiner Kallweit } else if (flags & AT24_FLAG_SERIAL) { 5744bb5c13cSHeiner Kallweit /* 5754bb5c13cSHeiner Kallweit * Otherwise the word address must begin with a '10' sequence, 5764bb5c13cSHeiner Kallweit * regardless of the intended address. 5774bb5c13cSHeiner Kallweit */ 5784bb5c13cSHeiner Kallweit return 0x0080; 5794bb5c13cSHeiner Kallweit } else { 5804bb5c13cSHeiner Kallweit return 0; 5814bb5c13cSHeiner Kallweit } 5824bb5c13cSHeiner Kallweit } 5834bb5c13cSHeiner Kallweit 58448b6a7d1SBartosz Golaszewski static int at24_probe(struct i2c_client *client) 5855195e509SWolfram Sang { 586eef69398SBartosz Golaszewski struct regmap_config regmap_config = { }; 5878cdc4e7eSBartosz Golaszewski struct nvmem_config nvmem_config = { }; 5884fa882c9SBartosz Golaszewski u32 byte_len, page_size, flags, addrw; 5894fa882c9SBartosz Golaszewski const struct at24_chip_data *cdata; 590021c7d7bSBartosz Golaszewski struct device *dev = &client->dev; 59134d43fafSBartosz Golaszewski bool i2c_fn_i2c, i2c_fn_block; 5925ca2b5b7SBartosz Golaszewski unsigned int i, num_addresses; 5935ca2b5b7SBartosz Golaszewski struct at24_data *at24; 5941e96078eSSakari Ailus bool full_power; 595551a1266SBartosz Golaszewski struct regmap *regmap; 5965ca2b5b7SBartosz Golaszewski bool writable; 59700f0ea70SBartosz Golaszewski u8 test_byte; 5985ca2b5b7SBartosz Golaszewski int err; 5995195e509SWolfram Sang 60034d43fafSBartosz Golaszewski i2c_fn_i2c = i2c_check_functionality(client->adapter, I2C_FUNC_I2C); 60134d43fafSBartosz Golaszewski i2c_fn_block = i2c_check_functionality(client->adapter, 60234d43fafSBartosz Golaszewski I2C_FUNC_SMBUS_WRITE_I2C_BLOCK); 60334d43fafSBartosz Golaszewski 6044fa882c9SBartosz Golaszewski cdata = at24_get_chip_data(dev); 6054fa882c9SBartosz Golaszewski if (IS_ERR(cdata)) 6064fa882c9SBartosz Golaszewski return PTR_ERR(cdata); 6074fa882c9SBartosz Golaszewski 6084fa882c9SBartosz Golaszewski err = device_property_read_u32(dev, "pagesize", &page_size); 609feb2f19bSBartosz Golaszewski if (err) 6104fa882c9SBartosz Golaszewski /* 6114fa882c9SBartosz Golaszewski * This is slow, but we can't know all eeproms, so we better 612dce91ba3SBartosz Golaszewski * play safe. Specifying custom eeprom-types via device tree 613dce91ba3SBartosz Golaszewski * or properties is recommended anyhow. 6144fa882c9SBartosz Golaszewski */ 6154fa882c9SBartosz Golaszewski page_size = 1; 6164fa882c9SBartosz Golaszewski 6174fa882c9SBartosz Golaszewski flags = cdata->flags; 6184fa882c9SBartosz Golaszewski if (device_property_present(dev, "read-only")) 6194fa882c9SBartosz Golaszewski flags |= AT24_FLAG_READONLY; 6204fa882c9SBartosz Golaszewski if (device_property_present(dev, "no-read-rollover")) 6214fa882c9SBartosz Golaszewski flags |= AT24_FLAG_NO_RDROL; 6224fa882c9SBartosz Golaszewski 6234fa882c9SBartosz Golaszewski err = device_property_read_u32(dev, "address-width", &addrw); 6244fa882c9SBartosz Golaszewski if (!err) { 6254fa882c9SBartosz Golaszewski switch (addrw) { 6264fa882c9SBartosz Golaszewski case 8: 6274fa882c9SBartosz Golaszewski if (flags & AT24_FLAG_ADDR16) 6284fa882c9SBartosz Golaszewski dev_warn(dev, 6294fa882c9SBartosz Golaszewski "Override address width to be 8, while default is 16\n"); 6304fa882c9SBartosz Golaszewski flags &= ~AT24_FLAG_ADDR16; 6314fa882c9SBartosz Golaszewski break; 6324fa882c9SBartosz Golaszewski case 16: 6334fa882c9SBartosz Golaszewski flags |= AT24_FLAG_ADDR16; 6344fa882c9SBartosz Golaszewski break; 6354fa882c9SBartosz Golaszewski default: 6364fa882c9SBartosz Golaszewski dev_warn(dev, "Bad \"address-width\" property: %u\n", 6374fa882c9SBartosz Golaszewski addrw); 6384fa882c9SBartosz Golaszewski } 6394fa882c9SBartosz Golaszewski } 6404fa882c9SBartosz Golaszewski 6414fa882c9SBartosz Golaszewski err = device_property_read_u32(dev, "size", &byte_len); 6424fa882c9SBartosz Golaszewski if (err) 6434fa882c9SBartosz Golaszewski byte_len = cdata->byte_len; 6445195e509SWolfram Sang 64534d43fafSBartosz Golaszewski if (!i2c_fn_i2c && !i2c_fn_block) 6464fa882c9SBartosz Golaszewski page_size = 1; 647551a1266SBartosz Golaszewski 6484fa882c9SBartosz Golaszewski if (!page_size) { 649021c7d7bSBartosz Golaszewski dev_err(dev, "page_size must not be 0!\n"); 650f0ac2363SNikolay Balandin return -EINVAL; 65145efe847SWolfram Sang } 652de5db101SBartosz Golaszewski 6534fa882c9SBartosz Golaszewski if (!is_power_of_2(page_size)) 654021c7d7bSBartosz Golaszewski dev_warn(dev, "page_size looks suspicious (no power of 2)!\n"); 6555195e509SWolfram Sang 656950bcbbeSBartosz Golaszewski err = device_property_read_u32(dev, "num-addresses", &num_addresses); 657950bcbbeSBartosz Golaszewski if (err) { 6584fa882c9SBartosz Golaszewski if (flags & AT24_FLAG_TAKE8ADDR) 6595195e509SWolfram Sang num_addresses = 8; 6605195e509SWolfram Sang else 6614fa882c9SBartosz Golaszewski num_addresses = DIV_ROUND_UP(byte_len, 6624fa882c9SBartosz Golaszewski (flags & AT24_FLAG_ADDR16) ? 65536 : 256); 663950bcbbeSBartosz Golaszewski } 6645195e509SWolfram Sang 6654fa882c9SBartosz Golaszewski if ((flags & AT24_FLAG_SERIAL) && (flags & AT24_FLAG_MAC)) { 666551a1266SBartosz Golaszewski dev_err(dev, 667551a1266SBartosz Golaszewski "invalid device data - cannot have both AT24_FLAG_SERIAL & AT24_FLAG_MAC."); 668551a1266SBartosz Golaszewski return -EINVAL; 669551a1266SBartosz Golaszewski } 670551a1266SBartosz Golaszewski 671eef69398SBartosz Golaszewski regmap_config.val_bits = 8; 6724fa882c9SBartosz Golaszewski regmap_config.reg_bits = (flags & AT24_FLAG_ADDR16) ? 16 : 8; 673d154316dSBartosz Golaszewski regmap_config.disable_locking = true; 6745c015258SHeiner Kallweit 675551a1266SBartosz Golaszewski regmap = devm_regmap_init_i2c(client, ®map_config); 676551a1266SBartosz Golaszewski if (IS_ERR(regmap)) 677551a1266SBartosz Golaszewski return PTR_ERR(regmap); 678551a1266SBartosz Golaszewski 67992e17647SHeiner Kallweit at24 = devm_kzalloc(dev, struct_size(at24, client_regmaps, num_addresses), 6809ae9d9bfSGustavo A. R. Silva GFP_KERNEL); 681f0ac2363SNikolay Balandin if (!at24) 682f0ac2363SNikolay Balandin return -ENOMEM; 6835195e509SWolfram Sang 6845195e509SWolfram Sang mutex_init(&at24->lock); 6854fa882c9SBartosz Golaszewski at24->byte_len = byte_len; 6864fa882c9SBartosz Golaszewski at24->page_size = page_size; 6874fa882c9SBartosz Golaszewski at24->flags = flags; 688a4423cedSJean Delvare at24->read_post = cdata->read_post; 689d08aea21SMaxim Kochetkov at24->bank_addr_shift = cdata->bank_addr_shift; 6905195e509SWolfram Sang at24->num_addresses = num_addresses; 6914fa882c9SBartosz Golaszewski at24->offset_adj = at24_get_offset_adj(flags, byte_len); 69292e17647SHeiner Kallweit at24->client_regmaps[0] = regmap; 6935195e509SWolfram Sang 694cd5676dbSBibby Hsieh at24->vcc_reg = devm_regulator_get(dev, "vcc"); 695cd5676dbSBibby Hsieh if (IS_ERR(at24->vcc_reg)) 696cd5676dbSBibby Hsieh return PTR_ERR(at24->vcc_reg); 6976ce261e8SBartosz Golaszewski 6984fa882c9SBartosz Golaszewski writable = !(flags & AT24_FLAG_READONLY); 6995195e509SWolfram Sang if (writable) { 700ec3c2d51SBartosz Golaszewski at24->write_max = min_t(unsigned int, 7014fa882c9SBartosz Golaszewski page_size, at24_io_limit); 70234d43fafSBartosz Golaszewski if (!i2c_fn_i2c && at24->write_max > I2C_SMBUS_BLOCK_MAX) 703a23727cbSHeiner Kallweit at24->write_max = I2C_SMBUS_BLOCK_MAX; 7045195e509SWolfram Sang } 7055195e509SWolfram Sang 7065195e509SWolfram Sang /* use dummy devices for multiple-address chips */ 7075195e509SWolfram Sang for (i = 1; i < num_addresses; i++) { 70892e17647SHeiner Kallweit err = at24_make_dummy_client(at24, i, client, ®map_config); 709e7308628SBartosz Golaszewski if (err) 71073b0d922SBartosz Golaszewski return err; 7115c015258SHeiner Kallweit } 7125195e509SWolfram Sang 71361f764c3SJon Hunter /* 714c36748acSJérôme Glisse * We initialize nvmem_config.id to NVMEM_DEVID_AUTO even if the 715c36748acSJérôme Glisse * label property is set as some platform can have multiple eeproms 716c36748acSJérôme Glisse * with same label and we can not register each of those with same 717c36748acSJérôme Glisse * label. Failing to register those eeproms trigger cascade failure 718c36748acSJérôme Glisse * on such platform. 71961f764c3SJon Hunter */ 720c36748acSJérôme Glisse nvmem_config.id = NVMEM_DEVID_AUTO; 721c36748acSJérôme Glisse 72261f764c3SJon Hunter if (device_property_present(dev, "label")) { 72361f764c3SJon Hunter err = device_property_read_string(dev, "label", 72461f764c3SJon Hunter &nvmem_config.name); 72561f764c3SJon Hunter if (err) 72661f764c3SJon Hunter return err; 72761f764c3SJon Hunter } else { 728021c7d7bSBartosz Golaszewski nvmem_config.name = dev_name(dev); 72961f764c3SJon Hunter } 73061f764c3SJon Hunter 73161f764c3SJon Hunter nvmem_config.type = NVMEM_TYPE_EEPROM; 732021c7d7bSBartosz Golaszewski nvmem_config.dev = dev; 7338cdc4e7eSBartosz Golaszewski nvmem_config.read_only = !writable; 73425e5ef30SJean Delvare nvmem_config.root_only = !(flags & AT24_FLAG_IRUGO); 7358cdc4e7eSBartosz Golaszewski nvmem_config.owner = THIS_MODULE; 7368cdc4e7eSBartosz Golaszewski nvmem_config.compat = true; 737021c7d7bSBartosz Golaszewski nvmem_config.base_dev = dev; 7388cdc4e7eSBartosz Golaszewski nvmem_config.reg_read = at24_read; 7398cdc4e7eSBartosz Golaszewski nvmem_config.reg_write = at24_write; 7408cdc4e7eSBartosz Golaszewski nvmem_config.priv = at24; 7418cdc4e7eSBartosz Golaszewski nvmem_config.stride = 1; 7428cdc4e7eSBartosz Golaszewski nvmem_config.word_size = 1; 7434fa882c9SBartosz Golaszewski nvmem_config.size = byte_len; 74457d15550SAndrew Lunn 745b20eb4c1SBartosz Golaszewski i2c_set_clientdata(client, at24); 746b20eb4c1SBartosz Golaszewski 7471e96078eSSakari Ailus full_power = acpi_dev_state_d0(&client->dev); 7481e96078eSSakari Ailus if (full_power) { 749cd5676dbSBibby Hsieh err = regulator_enable(at24->vcc_reg); 750cd5676dbSBibby Hsieh if (err) { 751cd5676dbSBibby Hsieh dev_err(dev, "Failed to enable vcc regulator\n"); 752cd5676dbSBibby Hsieh return err; 753cd5676dbSBibby Hsieh } 754cd5676dbSBibby Hsieh 755b20eb4c1SBartosz Golaszewski pm_runtime_set_active(dev); 7561e96078eSSakari Ailus } 757b20eb4c1SBartosz Golaszewski pm_runtime_enable(dev); 758b20eb4c1SBartosz Golaszewski 75945df80d7SVadym Kochan at24->nvmem = devm_nvmem_register(dev, &nvmem_config); 76045df80d7SVadym Kochan if (IS_ERR(at24->nvmem)) { 76145df80d7SVadym Kochan pm_runtime_disable(dev); 7622962484dSHsin-Yi Wang if (!pm_runtime_status_suspended(dev)) 76345df80d7SVadym Kochan regulator_disable(at24->vcc_reg); 76445df80d7SVadym Kochan return PTR_ERR(at24->nvmem); 76545df80d7SVadym Kochan } 76645df80d7SVadym Kochan 767b20eb4c1SBartosz Golaszewski /* 7681e96078eSSakari Ailus * Perform a one-byte test read to verify that the chip is functional, 7691e96078eSSakari Ailus * unless powering on the device is to be avoided during probe (i.e. 7701e96078eSSakari Ailus * it's powered off right now). 771b20eb4c1SBartosz Golaszewski */ 7721e96078eSSakari Ailus if (full_power) { 773b20eb4c1SBartosz Golaszewski err = at24_read(at24, 0, &test_byte, 1); 774b20eb4c1SBartosz Golaszewski if (err) { 775b20eb4c1SBartosz Golaszewski pm_runtime_disable(dev); 7762962484dSHsin-Yi Wang if (!pm_runtime_status_suspended(dev)) 777cd5676dbSBibby Hsieh regulator_disable(at24->vcc_reg); 778b20eb4c1SBartosz Golaszewski return -ENODEV; 77957d15550SAndrew Lunn } 7801e96078eSSakari Ailus } 7815195e509SWolfram Sang 78258d6fee5SMichael Auchter pm_runtime_idle(dev); 78358d6fee5SMichael Auchter 784285be87cSJean Delvare if (writable) 785285be87cSJean Delvare dev_info(dev, "%u byte %s EEPROM, writable, %u bytes/write\n", 786285be87cSJean Delvare byte_len, client->name, at24->write_max); 787285be87cSJean Delvare else 788285be87cSJean Delvare dev_info(dev, "%u byte %s EEPROM, read-only\n", 789285be87cSJean Delvare byte_len, client->name); 7905195e509SWolfram Sang 7915195e509SWolfram Sang return 0; 7925195e509SWolfram Sang } 7935195e509SWolfram Sang 794*ed5c2f5fSUwe Kleine-König static void at24_remove(struct i2c_client *client) 7955195e509SWolfram Sang { 796cd5676dbSBibby Hsieh struct at24_data *at24 = i2c_get_clientdata(client); 797cd5676dbSBibby Hsieh 79898e82010SDivagar Mohandass pm_runtime_disable(&client->dev); 7991e96078eSSakari Ailus if (acpi_dev_state_d0(&client->dev)) { 800cd5676dbSBibby Hsieh if (!pm_runtime_status_suspended(&client->dev)) 801cd5676dbSBibby Hsieh regulator_disable(at24->vcc_reg); 80298e82010SDivagar Mohandass pm_runtime_set_suspended(&client->dev); 8031e96078eSSakari Ailus } 8045195e509SWolfram Sang } 8055195e509SWolfram Sang 806cd5676dbSBibby Hsieh static int __maybe_unused at24_suspend(struct device *dev) 807cd5676dbSBibby Hsieh { 808cd5676dbSBibby Hsieh struct i2c_client *client = to_i2c_client(dev); 809cd5676dbSBibby Hsieh struct at24_data *at24 = i2c_get_clientdata(client); 810cd5676dbSBibby Hsieh 811cd5676dbSBibby Hsieh return regulator_disable(at24->vcc_reg); 812cd5676dbSBibby Hsieh } 813cd5676dbSBibby Hsieh 814cd5676dbSBibby Hsieh static int __maybe_unused at24_resume(struct device *dev) 815cd5676dbSBibby Hsieh { 816cd5676dbSBibby Hsieh struct i2c_client *client = to_i2c_client(dev); 817cd5676dbSBibby Hsieh struct at24_data *at24 = i2c_get_clientdata(client); 818cd5676dbSBibby Hsieh 819cd5676dbSBibby Hsieh return regulator_enable(at24->vcc_reg); 820cd5676dbSBibby Hsieh } 821cd5676dbSBibby Hsieh 822cd5676dbSBibby Hsieh static const struct dev_pm_ops at24_pm_ops = { 823cd5676dbSBibby Hsieh SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 824cd5676dbSBibby Hsieh pm_runtime_force_resume) 825cd5676dbSBibby Hsieh SET_RUNTIME_PM_OPS(at24_suspend, at24_resume, NULL) 826cd5676dbSBibby Hsieh }; 827cd5676dbSBibby Hsieh 8285195e509SWolfram Sang static struct i2c_driver at24_driver = { 8295195e509SWolfram Sang .driver = { 8305195e509SWolfram Sang .name = "at24", 831cd5676dbSBibby Hsieh .pm = &at24_pm_ops, 8327f2a2f0dSJavier Martinez Canillas .of_match_table = at24_of_match, 83340d8edc9SAndy Shevchenko .acpi_match_table = ACPI_PTR(at24_acpi_ids), 8345195e509SWolfram Sang }, 83548b6a7d1SBartosz Golaszewski .probe_new = at24_probe, 8362d6bed9cSBill Pemberton .remove = at24_remove, 8375195e509SWolfram Sang .id_table = at24_ids, 8381e96078eSSakari Ailus .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE, 8395195e509SWolfram Sang }; 8405195e509SWolfram Sang 8415195e509SWolfram Sang static int __init at24_init(void) 8425195e509SWolfram Sang { 843ec3c2d51SBartosz Golaszewski if (!at24_io_limit) { 844ec3c2d51SBartosz Golaszewski pr_err("at24: at24_io_limit must not be 0!\n"); 84545efe847SWolfram Sang return -EINVAL; 84645efe847SWolfram Sang } 84745efe847SWolfram Sang 848ec3c2d51SBartosz Golaszewski at24_io_limit = rounddown_pow_of_two(at24_io_limit); 8495195e509SWolfram Sang return i2c_add_driver(&at24_driver); 8505195e509SWolfram Sang } 8515195e509SWolfram Sang module_init(at24_init); 8525195e509SWolfram Sang 8535195e509SWolfram Sang static void __exit at24_exit(void) 8545195e509SWolfram Sang { 8555195e509SWolfram Sang i2c_del_driver(&at24_driver); 8565195e509SWolfram Sang } 8575195e509SWolfram Sang module_exit(at24_exit); 8585195e509SWolfram Sang 8595195e509SWolfram Sang MODULE_DESCRIPTION("Driver for most I2C EEPROMs"); 8605195e509SWolfram Sang MODULE_AUTHOR("David Brownell and Wolfram Sang"); 8615195e509SWolfram Sang MODULE_LICENSE("GPL"); 862