14ac0d3fbSBartosz Golaszewski // SPDX-License-Identifier: GPL-2.0+ 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 95195e509SWolfram Sang #include <linux/kernel.h> 105195e509SWolfram Sang #include <linux/init.h> 115195e509SWolfram Sang #include <linux/module.h> 127f2a2f0dSJavier Martinez Canillas #include <linux/of_device.h> 135195e509SWolfram Sang #include <linux/slab.h> 145195e509SWolfram Sang #include <linux/delay.h> 155195e509SWolfram Sang #include <linux/mutex.h> 165195e509SWolfram Sang #include <linux/mod_devicetable.h> 175195e509SWolfram Sang #include <linux/log2.h> 185195e509SWolfram Sang #include <linux/bitops.h> 195195e509SWolfram Sang #include <linux/jiffies.h> 20dd905a61SBen Gardner #include <linux/property.h> 2140d8edc9SAndy Shevchenko #include <linux/acpi.h> 225195e509SWolfram Sang #include <linux/i2c.h> 2357d15550SAndrew Lunn #include <linux/nvmem-provider.h> 245c015258SHeiner Kallweit #include <linux/regmap.h> 2598e82010SDivagar Mohandass #include <linux/pm_runtime.h> 266ce261e8SBartosz Golaszewski #include <linux/gpio/consumer.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 715c015258SHeiner Kallweit struct at24_client { 725c015258SHeiner Kallweit struct i2c_client *client; 735c015258SHeiner Kallweit struct regmap *regmap; 745c015258SHeiner Kallweit }; 755c015258SHeiner Kallweit 765195e509SWolfram Sang struct at24_data { 775195e509SWolfram Sang /* 785195e509SWolfram Sang * Lock protects against activities from other Linux tasks, 795195e509SWolfram Sang * but not from changes by other I2C masters. 805195e509SWolfram Sang */ 815195e509SWolfram Sang struct mutex lock; 825195e509SWolfram Sang 83aa4ce228SBartosz Golaszewski unsigned int write_max; 84aa4ce228SBartosz Golaszewski unsigned int num_addresses; 854bb5c13cSHeiner Kallweit unsigned int offset_adj; 865195e509SWolfram Sang 877c280664SBartosz Golaszewski u32 byte_len; 887c280664SBartosz Golaszewski u16 page_size; 897c280664SBartosz Golaszewski u8 flags; 907c280664SBartosz Golaszewski 9157d15550SAndrew Lunn struct nvmem_device *nvmem; 9257d15550SAndrew Lunn 936ce261e8SBartosz Golaszewski struct gpio_desc *wp_gpio; 946ce261e8SBartosz Golaszewski 955195e509SWolfram Sang /* 965195e509SWolfram Sang * Some chips tie up multiple I2C addresses; dummy devices reserve 975195e509SWolfram Sang * them for us, and we'll use them with SMBus calls. 985195e509SWolfram Sang */ 995c015258SHeiner Kallweit struct at24_client client[]; 1005195e509SWolfram Sang }; 1015195e509SWolfram Sang 1025195e509SWolfram Sang /* 1035195e509SWolfram Sang * This parameter is to help this driver avoid blocking other drivers out 1045195e509SWolfram Sang * of I2C for potentially troublesome amounts of time. With a 100 kHz I2C 1055195e509SWolfram Sang * clock, one 256 byte read takes about 1/43 second which is excessive; 1065195e509SWolfram Sang * but the 1/170 second it takes at 400 kHz may be quite reasonable; and 1075195e509SWolfram Sang * at 1 MHz (Fm+) a 1/430 second delay could easily be invisible. 1085195e509SWolfram Sang * 1095195e509SWolfram Sang * This value is forced to be a power of two so that writes align on pages. 1105195e509SWolfram Sang */ 111ec3c2d51SBartosz Golaszewski static unsigned int at24_io_limit = 128; 112ec3c2d51SBartosz Golaszewski module_param_named(io_limit, at24_io_limit, uint, 0); 113ec3c2d51SBartosz Golaszewski MODULE_PARM_DESC(at24_io_limit, "Maximum bytes per I/O (default 128)"); 1145195e509SWolfram Sang 1155195e509SWolfram Sang /* 1165195e509SWolfram Sang * Specs often allow 5 msec for a page write, sometimes 20 msec; 1175195e509SWolfram Sang * it's important to recover from write timeouts. 1185195e509SWolfram Sang */ 119ec3c2d51SBartosz Golaszewski static unsigned int at24_write_timeout = 25; 120ec3c2d51SBartosz Golaszewski module_param_named(write_timeout, at24_write_timeout, uint, 0); 121ec3c2d51SBartosz Golaszewski MODULE_PARM_DESC(at24_write_timeout, "Time (in ms) to try writes (default 25)"); 1225195e509SWolfram Sang 123b680f4faSSven Van Asbroeck struct at24_chip_data { 124b680f4faSSven Van Asbroeck u32 byte_len; 125b680f4faSSven Van Asbroeck u8 flags; 126b680f4faSSven Van Asbroeck }; 127b680f4faSSven Van Asbroeck 128b680f4faSSven Van Asbroeck #define AT24_CHIP_DATA(_name, _len, _flags) \ 129b680f4faSSven Van Asbroeck static const struct at24_chip_data _name = { \ 130b680f4faSSven Van Asbroeck .byte_len = _len, .flags = _flags, \ 131b680f4faSSven Van Asbroeck } 132b680f4faSSven Van Asbroeck 1335195e509SWolfram Sang /* needs 8 addresses as A0-A2 are ignored */ 134b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c00, 128 / 8, AT24_FLAG_TAKE8ADDR); 1355195e509SWolfram Sang /* old variants can't be handled with this generic entry! */ 136b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c01, 1024 / 8, 0); 137b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs01, 16, 138b680f4faSSven Van Asbroeck AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 139b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c02, 2048 / 8, 0); 140b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs02, 16, 141b680f4faSSven Van Asbroeck AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 142b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24mac402, 48 / 8, 143b680f4faSSven Van Asbroeck AT24_FLAG_MAC | AT24_FLAG_READONLY); 144b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24mac602, 64 / 8, 145b680f4faSSven Van Asbroeck AT24_FLAG_MAC | AT24_FLAG_READONLY); 1465195e509SWolfram Sang /* spd is a 24c02 in memory DIMMs */ 147b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_spd, 2048 / 8, 148b680f4faSSven Van Asbroeck AT24_FLAG_READONLY | AT24_FLAG_IRUGO); 149b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c04, 4096 / 8, 0); 150b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs04, 16, 151b680f4faSSven Van Asbroeck AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 1525195e509SWolfram Sang /* 24rf08 quirk is handled at i2c-core */ 153b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c08, 8192 / 8, 0); 154b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs08, 16, 155b680f4faSSven Van Asbroeck AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 156b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c16, 16384 / 8, 0); 157b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs16, 16, 158b680f4faSSven Van Asbroeck AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 159b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c32, 32768 / 8, AT24_FLAG_ADDR16); 160b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs32, 16, 161b680f4faSSven Van Asbroeck AT24_FLAG_ADDR16 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 162b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c64, 65536 / 8, AT24_FLAG_ADDR16); 163b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24cs64, 16, 164b680f4faSSven Van Asbroeck AT24_FLAG_ADDR16 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); 165b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c128, 131072 / 8, AT24_FLAG_ADDR16); 166b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c256, 262144 / 8, AT24_FLAG_ADDR16); 167b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c512, 524288 / 8, AT24_FLAG_ADDR16); 168b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_24c1024, 1048576 / 8, AT24_FLAG_ADDR16); 16937cf28d3SAdrian Bunk AT24_CHIP_DATA(at24_data_24c2048, 2097152 / 8, AT24_FLAG_ADDR16); 170b680f4faSSven Van Asbroeck /* identical to 24c08 ? */ 171b680f4faSSven Van Asbroeck AT24_CHIP_DATA(at24_data_INT3499, 8192 / 8, 0); 172b680f4faSSven Van Asbroeck 173b680f4faSSven Van Asbroeck static const struct i2c_device_id at24_ids[] = { 174b680f4faSSven Van Asbroeck { "24c00", (kernel_ulong_t)&at24_data_24c00 }, 175b680f4faSSven Van Asbroeck { "24c01", (kernel_ulong_t)&at24_data_24c01 }, 176b680f4faSSven Van Asbroeck { "24cs01", (kernel_ulong_t)&at24_data_24cs01 }, 177b680f4faSSven Van Asbroeck { "24c02", (kernel_ulong_t)&at24_data_24c02 }, 178b680f4faSSven Van Asbroeck { "24cs02", (kernel_ulong_t)&at24_data_24cs02 }, 179b680f4faSSven Van Asbroeck { "24mac402", (kernel_ulong_t)&at24_data_24mac402 }, 180b680f4faSSven Van Asbroeck { "24mac602", (kernel_ulong_t)&at24_data_24mac602 }, 181b680f4faSSven Van Asbroeck { "spd", (kernel_ulong_t)&at24_data_spd }, 182b680f4faSSven Van Asbroeck { "24c04", (kernel_ulong_t)&at24_data_24c04 }, 183b680f4faSSven Van Asbroeck { "24cs04", (kernel_ulong_t)&at24_data_24cs04 }, 184b680f4faSSven Van Asbroeck { "24c08", (kernel_ulong_t)&at24_data_24c08 }, 185b680f4faSSven Van Asbroeck { "24cs08", (kernel_ulong_t)&at24_data_24cs08 }, 186b680f4faSSven Van Asbroeck { "24c16", (kernel_ulong_t)&at24_data_24c16 }, 187b680f4faSSven Van Asbroeck { "24cs16", (kernel_ulong_t)&at24_data_24cs16 }, 188b680f4faSSven Van Asbroeck { "24c32", (kernel_ulong_t)&at24_data_24c32 }, 189b680f4faSSven Van Asbroeck { "24cs32", (kernel_ulong_t)&at24_data_24cs32 }, 190b680f4faSSven Van Asbroeck { "24c64", (kernel_ulong_t)&at24_data_24c64 }, 191b680f4faSSven Van Asbroeck { "24cs64", (kernel_ulong_t)&at24_data_24cs64 }, 192b680f4faSSven Van Asbroeck { "24c128", (kernel_ulong_t)&at24_data_24c128 }, 193b680f4faSSven Van Asbroeck { "24c256", (kernel_ulong_t)&at24_data_24c256 }, 194b680f4faSSven Van Asbroeck { "24c512", (kernel_ulong_t)&at24_data_24c512 }, 195b680f4faSSven Van Asbroeck { "24c1024", (kernel_ulong_t)&at24_data_24c1024 }, 19637cf28d3SAdrian Bunk { "24c2048", (kernel_ulong_t)&at24_data_24c2048 }, 1975195e509SWolfram Sang { "at24", 0 }, 1985195e509SWolfram Sang { /* END OF LIST */ } 1995195e509SWolfram Sang }; 2005195e509SWolfram Sang MODULE_DEVICE_TABLE(i2c, at24_ids); 2015195e509SWolfram Sang 2027f2a2f0dSJavier Martinez Canillas static const struct of_device_id at24_of_match[] = { 203b680f4faSSven Van Asbroeck { .compatible = "atmel,24c00", .data = &at24_data_24c00 }, 204b680f4faSSven Van Asbroeck { .compatible = "atmel,24c01", .data = &at24_data_24c01 }, 2050f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs01", .data = &at24_data_24cs01 }, 206b680f4faSSven Van Asbroeck { .compatible = "atmel,24c02", .data = &at24_data_24c02 }, 2070f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs02", .data = &at24_data_24cs02 }, 2080f30aca7SBartosz Golaszewski { .compatible = "atmel,24mac402", .data = &at24_data_24mac402 }, 2090f30aca7SBartosz Golaszewski { .compatible = "atmel,24mac602", .data = &at24_data_24mac602 }, 210b680f4faSSven Van Asbroeck { .compatible = "atmel,spd", .data = &at24_data_spd }, 211b680f4faSSven Van Asbroeck { .compatible = "atmel,24c04", .data = &at24_data_24c04 }, 2120f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs04", .data = &at24_data_24cs04 }, 213b680f4faSSven Van Asbroeck { .compatible = "atmel,24c08", .data = &at24_data_24c08 }, 2140f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs08", .data = &at24_data_24cs08 }, 215b680f4faSSven Van Asbroeck { .compatible = "atmel,24c16", .data = &at24_data_24c16 }, 2160f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs16", .data = &at24_data_24cs16 }, 217b680f4faSSven Van Asbroeck { .compatible = "atmel,24c32", .data = &at24_data_24c32 }, 2180f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs32", .data = &at24_data_24cs32 }, 219b680f4faSSven Van Asbroeck { .compatible = "atmel,24c64", .data = &at24_data_24c64 }, 2200f30aca7SBartosz Golaszewski { .compatible = "atmel,24cs64", .data = &at24_data_24cs64 }, 221b680f4faSSven Van Asbroeck { .compatible = "atmel,24c128", .data = &at24_data_24c128 }, 222b680f4faSSven Van Asbroeck { .compatible = "atmel,24c256", .data = &at24_data_24c256 }, 223b680f4faSSven Van Asbroeck { .compatible = "atmel,24c512", .data = &at24_data_24c512 }, 224b680f4faSSven Van Asbroeck { .compatible = "atmel,24c1024", .data = &at24_data_24c1024 }, 22537cf28d3SAdrian Bunk { .compatible = "atmel,24c2048", .data = &at24_data_24c2048 }, 226b680f4faSSven Van Asbroeck { /* END OF LIST */ }, 2277f2a2f0dSJavier Martinez Canillas }; 2287f2a2f0dSJavier Martinez Canillas MODULE_DEVICE_TABLE(of, at24_of_match); 2297f2a2f0dSJavier Martinez Canillas 23040d8edc9SAndy Shevchenko static const struct acpi_device_id at24_acpi_ids[] = { 231b680f4faSSven Van Asbroeck { "INT3499", (kernel_ulong_t)&at24_data_INT3499 }, 232b680f4faSSven Van Asbroeck { /* END OF LIST */ } 23340d8edc9SAndy Shevchenko }; 23440d8edc9SAndy Shevchenko MODULE_DEVICE_TABLE(acpi, at24_acpi_ids); 23540d8edc9SAndy Shevchenko 2365195e509SWolfram Sang /* 2375195e509SWolfram Sang * This routine supports chips which consume multiple I2C addresses. It 2385195e509SWolfram Sang * computes the addressing information to be used for a given r/w request. 2395195e509SWolfram Sang * Assumes that sanity checks for offset happened at sysfs-layer. 2409afd6866SBartosz Golaszewski * 2419afd6866SBartosz Golaszewski * Slave address and byte offset derive from the offset. Always 2429afd6866SBartosz Golaszewski * set the byte address; on a multi-master board, another master 2439afd6866SBartosz Golaszewski * may have changed the chip's "current" address pointer. 2445195e509SWolfram Sang */ 24546049486SHeiner Kallweit static struct at24_client *at24_translate_offset(struct at24_data *at24, 2462da78ac3SBartosz Golaszewski unsigned int *offset) 2475195e509SWolfram Sang { 248aa4ce228SBartosz Golaszewski unsigned int i; 2495195e509SWolfram Sang 2507c280664SBartosz Golaszewski if (at24->flags & AT24_FLAG_ADDR16) { 2515195e509SWolfram Sang i = *offset >> 16; 2525195e509SWolfram Sang *offset &= 0xffff; 2535195e509SWolfram Sang } else { 2545195e509SWolfram Sang i = *offset >> 8; 2555195e509SWolfram Sang *offset &= 0xff; 2565195e509SWolfram Sang } 2575195e509SWolfram Sang 25846049486SHeiner Kallweit return &at24->client[i]; 2595195e509SWolfram Sang } 2605195e509SWolfram Sang 261f1a640c5SBartosz Golaszewski static struct device *at24_base_client_dev(struct at24_data *at24) 262f1a640c5SBartosz Golaszewski { 263f1a640c5SBartosz Golaszewski return &at24->client[0].client->dev; 264f1a640c5SBartosz Golaszewski } 265f1a640c5SBartosz Golaszewski 266e32213fbSSven Van Asbroeck static size_t at24_adjust_read_count(struct at24_data *at24, 267e32213fbSSven Van Asbroeck unsigned int offset, size_t count) 268e32213fbSSven Van Asbroeck { 269e32213fbSSven Van Asbroeck unsigned int bits; 270e32213fbSSven Van Asbroeck size_t remainder; 271e32213fbSSven Van Asbroeck 272e32213fbSSven Van Asbroeck /* 273e32213fbSSven Van Asbroeck * In case of multi-address chips that don't rollover reads to 274e32213fbSSven Van Asbroeck * the next slave address: truncate the count to the slave boundary, 275e32213fbSSven Van Asbroeck * so that the read never straddles slaves. 276e32213fbSSven Van Asbroeck */ 2777c280664SBartosz Golaszewski if (at24->flags & AT24_FLAG_NO_RDROL) { 2787c280664SBartosz Golaszewski bits = (at24->flags & AT24_FLAG_ADDR16) ? 16 : 8; 279e32213fbSSven Van Asbroeck remainder = BIT(bits) - offset; 280e32213fbSSven Van Asbroeck if (count > remainder) 281e32213fbSSven Van Asbroeck count = remainder; 282e32213fbSSven Van Asbroeck } 283e32213fbSSven Van Asbroeck 284ec3c2d51SBartosz Golaszewski if (count > at24_io_limit) 285ec3c2d51SBartosz Golaszewski count = at24_io_limit; 286e32213fbSSven Van Asbroeck 287e32213fbSSven Van Asbroeck return count; 288e32213fbSSven Van Asbroeck } 289e32213fbSSven Van Asbroeck 2904bb5c13cSHeiner Kallweit static ssize_t at24_regmap_read(struct at24_data *at24, char *buf, 2914bb5c13cSHeiner Kallweit unsigned int offset, size_t count) 2924bb5c13cSHeiner Kallweit { 2934bb5c13cSHeiner Kallweit unsigned long timeout, read_time; 2944bb5c13cSHeiner Kallweit struct at24_client *at24_client; 2954bb5c13cSHeiner Kallweit struct i2c_client *client; 2964bb5c13cSHeiner Kallweit struct regmap *regmap; 2974bb5c13cSHeiner Kallweit int ret; 2984bb5c13cSHeiner Kallweit 2994bb5c13cSHeiner Kallweit at24_client = at24_translate_offset(at24, &offset); 3004bb5c13cSHeiner Kallweit regmap = at24_client->regmap; 3014bb5c13cSHeiner Kallweit client = at24_client->client; 302e32213fbSSven Van Asbroeck count = at24_adjust_read_count(at24, offset, count); 3034bb5c13cSHeiner Kallweit 3044bb5c13cSHeiner Kallweit /* adjust offset for mac and serial read ops */ 3054bb5c13cSHeiner Kallweit offset += at24->offset_adj; 3064bb5c13cSHeiner Kallweit 3079a9e295eSWang Xin timeout = jiffies + msecs_to_jiffies(at24_write_timeout); 3089a9e295eSWang Xin do { 3099a9e295eSWang Xin /* 3109a9e295eSWang Xin * The timestamp shall be taken before the actual operation 3119a9e295eSWang Xin * to avoid a premature timeout in case of high CPU load. 3129a9e295eSWang Xin */ 3139a9e295eSWang Xin read_time = jiffies; 3149a9e295eSWang Xin 3154bb5c13cSHeiner Kallweit ret = regmap_bulk_read(regmap, offset, buf, count); 3164bb5c13cSHeiner Kallweit dev_dbg(&client->dev, "read %zu@%d --> %d (%ld)\n", 3174bb5c13cSHeiner Kallweit count, offset, ret, jiffies); 3184bb5c13cSHeiner Kallweit if (!ret) 3194bb5c13cSHeiner Kallweit return count; 3209a9e295eSWang Xin 3219a9e295eSWang Xin usleep_range(1000, 1500); 3229a9e295eSWang Xin } while (time_before(read_time, timeout)); 3234bb5c13cSHeiner Kallweit 3244bb5c13cSHeiner Kallweit return -ETIMEDOUT; 3254bb5c13cSHeiner Kallweit } 3264bb5c13cSHeiner Kallweit 3275195e509SWolfram Sang /* 3285195e509SWolfram Sang * Note that if the hardware write-protect pin is pulled high, the whole 3295195e509SWolfram Sang * chip is normally write protected. But there are plenty of product 3305195e509SWolfram Sang * variants here, including OTP fuses and partial chip protect. 3315195e509SWolfram Sang * 332cd0c8615SBartosz Golaszewski * We only use page mode writes; the alternative is sloooow. These routines 333cd0c8615SBartosz Golaszewski * write at most one page. 3345195e509SWolfram Sang */ 335cd0c8615SBartosz Golaszewski 336cd0c8615SBartosz Golaszewski static size_t at24_adjust_write_count(struct at24_data *at24, 3372da78ac3SBartosz Golaszewski unsigned int offset, size_t count) 3385195e509SWolfram Sang { 339aa4ce228SBartosz Golaszewski unsigned int next_page; 3405195e509SWolfram Sang 3415195e509SWolfram Sang /* write_max is at most a page */ 3425195e509SWolfram Sang if (count > at24->write_max) 3435195e509SWolfram Sang count = at24->write_max; 3445195e509SWolfram Sang 3455195e509SWolfram Sang /* Never roll over backwards, to the start of this page */ 3467c280664SBartosz Golaszewski next_page = roundup(offset + 1, at24->page_size); 3475195e509SWolfram Sang if (offset + count > next_page) 3485195e509SWolfram Sang count = next_page - offset; 3495195e509SWolfram Sang 350cd0c8615SBartosz Golaszewski return count; 351cd0c8615SBartosz Golaszewski } 352cd0c8615SBartosz Golaszewski 3538e5888e1SHeiner Kallweit static ssize_t at24_regmap_write(struct at24_data *at24, const char *buf, 3548e5888e1SHeiner Kallweit unsigned int offset, size_t count) 3558e5888e1SHeiner Kallweit { 3568e5888e1SHeiner Kallweit unsigned long timeout, write_time; 3578e5888e1SHeiner Kallweit struct at24_client *at24_client; 3588e5888e1SHeiner Kallweit struct i2c_client *client; 3598e5888e1SHeiner Kallweit struct regmap *regmap; 3608e5888e1SHeiner Kallweit int ret; 3618e5888e1SHeiner Kallweit 3628e5888e1SHeiner Kallweit at24_client = at24_translate_offset(at24, &offset); 3638e5888e1SHeiner Kallweit regmap = at24_client->regmap; 3648e5888e1SHeiner Kallweit client = at24_client->client; 3658e5888e1SHeiner Kallweit count = at24_adjust_write_count(at24, offset, count); 3669a9e295eSWang Xin timeout = jiffies + msecs_to_jiffies(at24_write_timeout); 3678e5888e1SHeiner Kallweit 3689a9e295eSWang Xin do { 3699a9e295eSWang Xin /* 3709a9e295eSWang Xin * The timestamp shall be taken before the actual operation 3719a9e295eSWang Xin * to avoid a premature timeout in case of high CPU load. 3729a9e295eSWang Xin */ 3739a9e295eSWang Xin write_time = jiffies; 3749a9e295eSWang Xin 3758e5888e1SHeiner Kallweit ret = regmap_bulk_write(regmap, offset, buf, count); 3768e5888e1SHeiner Kallweit dev_dbg(&client->dev, "write %zu@%d --> %d (%ld)\n", 3778e5888e1SHeiner Kallweit count, offset, ret, jiffies); 3788e5888e1SHeiner Kallweit if (!ret) 3798e5888e1SHeiner Kallweit return count; 3809a9e295eSWang Xin 3819a9e295eSWang Xin usleep_range(1000, 1500); 3829a9e295eSWang Xin } while (time_before(write_time, timeout)); 3838e5888e1SHeiner Kallweit 3848e5888e1SHeiner Kallweit return -ETIMEDOUT; 3858e5888e1SHeiner Kallweit } 3868e5888e1SHeiner Kallweit 387d5bc0047SBartosz Golaszewski static int at24_read(void *priv, unsigned int off, void *val, size_t count) 388d5bc0047SBartosz Golaszewski { 3895ca2b5b7SBartosz Golaszewski struct at24_data *at24; 3905ca2b5b7SBartosz Golaszewski struct device *dev; 391d5bc0047SBartosz Golaszewski char *buf = val; 39298e82010SDivagar Mohandass int ret; 393d5bc0047SBartosz Golaszewski 3945ca2b5b7SBartosz Golaszewski at24 = priv; 395f1a640c5SBartosz Golaszewski dev = at24_base_client_dev(at24); 3965ca2b5b7SBartosz Golaszewski 397d5bc0047SBartosz Golaszewski if (unlikely(!count)) 398d5bc0047SBartosz Golaszewski return count; 399d5bc0047SBartosz Golaszewski 4007c280664SBartosz Golaszewski if (off + count > at24->byte_len) 401d9bcd462SHeiner Kallweit return -EINVAL; 402d9bcd462SHeiner Kallweit 403f9ecc83fSSakari Ailus ret = pm_runtime_get_sync(dev); 40498e82010SDivagar Mohandass if (ret < 0) { 405f9ecc83fSSakari Ailus pm_runtime_put_noidle(dev); 40698e82010SDivagar Mohandass return ret; 40798e82010SDivagar Mohandass } 40898e82010SDivagar Mohandass 409d5bc0047SBartosz Golaszewski /* 410d5bc0047SBartosz Golaszewski * Read data from chip, protecting against concurrent updates 411d5bc0047SBartosz Golaszewski * from this host, but not from other I2C masters. 412d5bc0047SBartosz Golaszewski */ 413d5bc0047SBartosz Golaszewski mutex_lock(&at24->lock); 414d5bc0047SBartosz Golaszewski 415d5bc0047SBartosz Golaszewski while (count) { 416eb27fde2SBartosz Golaszewski ret = at24_regmap_read(at24, buf, off, count); 417eb27fde2SBartosz Golaszewski if (ret < 0) { 418d5bc0047SBartosz Golaszewski mutex_unlock(&at24->lock); 419f9ecc83fSSakari Ailus pm_runtime_put(dev); 420eb27fde2SBartosz Golaszewski return ret; 421d5bc0047SBartosz Golaszewski } 422eb27fde2SBartosz Golaszewski buf += ret; 423eb27fde2SBartosz Golaszewski off += ret; 424eb27fde2SBartosz Golaszewski count -= ret; 425d5bc0047SBartosz Golaszewski } 426d5bc0047SBartosz Golaszewski 427d5bc0047SBartosz Golaszewski mutex_unlock(&at24->lock); 428d5bc0047SBartosz Golaszewski 429f9ecc83fSSakari Ailus pm_runtime_put(dev); 43098e82010SDivagar Mohandass 431d5bc0047SBartosz Golaszewski return 0; 432d5bc0047SBartosz Golaszewski } 433d5bc0047SBartosz Golaszewski 434cf0361a2SSrinivas Kandagatla static int at24_write(void *priv, unsigned int off, void *val, size_t count) 4355195e509SWolfram Sang { 4365ca2b5b7SBartosz Golaszewski struct at24_data *at24; 4375ca2b5b7SBartosz Golaszewski struct device *dev; 438cf0361a2SSrinivas Kandagatla char *buf = val; 43998e82010SDivagar Mohandass int ret; 4405195e509SWolfram Sang 4415ca2b5b7SBartosz Golaszewski at24 = priv; 442f1a640c5SBartosz Golaszewski dev = at24_base_client_dev(at24); 4435ca2b5b7SBartosz Golaszewski 4445195e509SWolfram Sang if (unlikely(!count)) 445cf0361a2SSrinivas Kandagatla return -EINVAL; 4465195e509SWolfram Sang 4477c280664SBartosz Golaszewski if (off + count > at24->byte_len) 448d9bcd462SHeiner Kallweit return -EINVAL; 449d9bcd462SHeiner Kallweit 450f9ecc83fSSakari Ailus ret = pm_runtime_get_sync(dev); 45198e82010SDivagar Mohandass if (ret < 0) { 452f9ecc83fSSakari Ailus pm_runtime_put_noidle(dev); 45398e82010SDivagar Mohandass return ret; 45498e82010SDivagar Mohandass } 45598e82010SDivagar Mohandass 4565195e509SWolfram Sang /* 4575195e509SWolfram Sang * Write data to chip, protecting against concurrent updates 4585195e509SWolfram Sang * from this host, but not from other I2C masters. 4595195e509SWolfram Sang */ 4605195e509SWolfram Sang mutex_lock(&at24->lock); 4616ce261e8SBartosz Golaszewski gpiod_set_value_cansleep(at24->wp_gpio, 0); 4625195e509SWolfram Sang 4635195e509SWolfram Sang while (count) { 464c4fee330SBartosz Golaszewski ret = at24_regmap_write(at24, buf, off, count); 465c4fee330SBartosz Golaszewski if (ret < 0) { 4666ce261e8SBartosz Golaszewski gpiod_set_value_cansleep(at24->wp_gpio, 1); 467cf0361a2SSrinivas Kandagatla mutex_unlock(&at24->lock); 468f9ecc83fSSakari Ailus pm_runtime_put(dev); 469c4fee330SBartosz Golaszewski return ret; 4705195e509SWolfram Sang } 471c4fee330SBartosz Golaszewski buf += ret; 472c4fee330SBartosz Golaszewski off += ret; 473c4fee330SBartosz Golaszewski count -= ret; 4745195e509SWolfram Sang } 4755195e509SWolfram Sang 4766ce261e8SBartosz Golaszewski gpiod_set_value_cansleep(at24->wp_gpio, 1); 4775195e509SWolfram Sang mutex_unlock(&at24->lock); 4785195e509SWolfram Sang 479f9ecc83fSSakari Ailus pm_runtime_put(dev); 48098e82010SDivagar Mohandass 48157d15550SAndrew Lunn return 0; 48257d15550SAndrew Lunn } 48357d15550SAndrew Lunn 4844fa882c9SBartosz Golaszewski static const struct at24_chip_data *at24_get_chip_data(struct device *dev) 485feb2f19bSBartosz Golaszewski { 486feb2f19bSBartosz Golaszewski struct device_node *of_node = dev->of_node; 487feb2f19bSBartosz Golaszewski const struct at24_chip_data *cdata; 488feb2f19bSBartosz Golaszewski const struct i2c_device_id *id; 489feb2f19bSBartosz Golaszewski 490feb2f19bSBartosz Golaszewski id = i2c_match_id(at24_ids, to_i2c_client(dev)); 491feb2f19bSBartosz Golaszewski 492feb2f19bSBartosz Golaszewski /* 493feb2f19bSBartosz Golaszewski * The I2C core allows OF nodes compatibles to match against the 494feb2f19bSBartosz Golaszewski * I2C device ID table as a fallback, so check not only if an OF 495feb2f19bSBartosz Golaszewski * node is present but also if it matches an OF device ID entry. 496feb2f19bSBartosz Golaszewski */ 497feb2f19bSBartosz Golaszewski if (of_node && of_match_device(at24_of_match, dev)) 498feb2f19bSBartosz Golaszewski cdata = of_device_get_match_data(dev); 499feb2f19bSBartosz Golaszewski else if (id) 5005fa4d14eSBartosz Golaszewski cdata = (void *)id->driver_data; 501feb2f19bSBartosz Golaszewski else 502feb2f19bSBartosz Golaszewski cdata = acpi_device_get_match_data(dev); 503feb2f19bSBartosz Golaszewski 504feb2f19bSBartosz Golaszewski if (!cdata) 5054fa882c9SBartosz Golaszewski return ERR_PTR(-ENODEV); 506feb2f19bSBartosz Golaszewski 5074fa882c9SBartosz Golaszewski return cdata; 508feb2f19bSBartosz Golaszewski } 509feb2f19bSBartosz Golaszewski 51073b0d922SBartosz Golaszewski static int at24_make_dummy_client(struct at24_data *at24, unsigned int index, 51173b0d922SBartosz Golaszewski struct regmap_config *regmap_config) 51273b0d922SBartosz Golaszewski { 51373b0d922SBartosz Golaszewski struct i2c_client *base_client, *dummy_client; 51473b0d922SBartosz Golaszewski unsigned short int addr; 51573b0d922SBartosz Golaszewski struct regmap *regmap; 51673b0d922SBartosz Golaszewski struct device *dev; 51773b0d922SBartosz Golaszewski 51873b0d922SBartosz Golaszewski base_client = at24->client[0].client; 51973b0d922SBartosz Golaszewski dev = &base_client->dev; 52073b0d922SBartosz Golaszewski addr = base_client->addr + index; 52173b0d922SBartosz Golaszewski 522e7308628SBartosz Golaszewski dummy_client = devm_i2c_new_dummy_device(dev, base_client->adapter, 52373b0d922SBartosz Golaszewski base_client->addr + index); 524e7308628SBartosz Golaszewski if (IS_ERR(dummy_client)) 525e7308628SBartosz Golaszewski return PTR_ERR(dummy_client); 52673b0d922SBartosz Golaszewski 52773b0d922SBartosz Golaszewski regmap = devm_regmap_init_i2c(dummy_client, regmap_config); 528e7308628SBartosz Golaszewski if (IS_ERR(regmap)) 52973b0d922SBartosz Golaszewski return PTR_ERR(regmap); 53073b0d922SBartosz Golaszewski 53173b0d922SBartosz Golaszewski at24->client[index].client = dummy_client; 53273b0d922SBartosz Golaszewski at24->client[index].regmap = regmap; 53373b0d922SBartosz Golaszewski 53473b0d922SBartosz Golaszewski return 0; 53573b0d922SBartosz Golaszewski } 53673b0d922SBartosz Golaszewski 5374bb5c13cSHeiner Kallweit static unsigned int at24_get_offset_adj(u8 flags, unsigned int byte_len) 5384bb5c13cSHeiner Kallweit { 5394bb5c13cSHeiner Kallweit if (flags & AT24_FLAG_MAC) { 5404bb5c13cSHeiner Kallweit /* EUI-48 starts from 0x9a, EUI-64 from 0x98 */ 5414bb5c13cSHeiner Kallweit return 0xa0 - byte_len; 5424bb5c13cSHeiner Kallweit } else if (flags & AT24_FLAG_SERIAL && flags & AT24_FLAG_ADDR16) { 5434bb5c13cSHeiner Kallweit /* 5444bb5c13cSHeiner Kallweit * For 16 bit address pointers, the word address must contain 5454bb5c13cSHeiner Kallweit * a '10' sequence in bits 11 and 10 regardless of the 5464bb5c13cSHeiner Kallweit * intended position of the address pointer. 5474bb5c13cSHeiner Kallweit */ 5484bb5c13cSHeiner Kallweit return 0x0800; 5494bb5c13cSHeiner Kallweit } else if (flags & AT24_FLAG_SERIAL) { 5504bb5c13cSHeiner Kallweit /* 5514bb5c13cSHeiner Kallweit * Otherwise the word address must begin with a '10' sequence, 5524bb5c13cSHeiner Kallweit * regardless of the intended address. 5534bb5c13cSHeiner Kallweit */ 5544bb5c13cSHeiner Kallweit return 0x0080; 5554bb5c13cSHeiner Kallweit } else { 5564bb5c13cSHeiner Kallweit return 0; 5574bb5c13cSHeiner Kallweit } 5584bb5c13cSHeiner Kallweit } 5594bb5c13cSHeiner Kallweit 56048b6a7d1SBartosz Golaszewski static int at24_probe(struct i2c_client *client) 5615195e509SWolfram Sang { 562eef69398SBartosz Golaszewski struct regmap_config regmap_config = { }; 5638cdc4e7eSBartosz Golaszewski struct nvmem_config nvmem_config = { }; 5644fa882c9SBartosz Golaszewski u32 byte_len, page_size, flags, addrw; 5654fa882c9SBartosz Golaszewski const struct at24_chip_data *cdata; 566021c7d7bSBartosz Golaszewski struct device *dev = &client->dev; 56734d43fafSBartosz Golaszewski bool i2c_fn_i2c, i2c_fn_block; 5685ca2b5b7SBartosz Golaszewski unsigned int i, num_addresses; 5695ca2b5b7SBartosz Golaszewski struct at24_data *at24; 570551a1266SBartosz Golaszewski struct regmap *regmap; 57111288b7cSBartosz Golaszewski size_t at24_size; 5725ca2b5b7SBartosz Golaszewski bool writable; 57300f0ea70SBartosz Golaszewski u8 test_byte; 5745ca2b5b7SBartosz Golaszewski int err; 5755195e509SWolfram Sang 57634d43fafSBartosz Golaszewski i2c_fn_i2c = i2c_check_functionality(client->adapter, I2C_FUNC_I2C); 57734d43fafSBartosz Golaszewski i2c_fn_block = i2c_check_functionality(client->adapter, 57834d43fafSBartosz Golaszewski I2C_FUNC_SMBUS_WRITE_I2C_BLOCK); 57934d43fafSBartosz Golaszewski 5804fa882c9SBartosz Golaszewski cdata = at24_get_chip_data(dev); 5814fa882c9SBartosz Golaszewski if (IS_ERR(cdata)) 5824fa882c9SBartosz Golaszewski return PTR_ERR(cdata); 5834fa882c9SBartosz Golaszewski 5844fa882c9SBartosz Golaszewski err = device_property_read_u32(dev, "pagesize", &page_size); 585feb2f19bSBartosz Golaszewski if (err) 5864fa882c9SBartosz Golaszewski /* 5874fa882c9SBartosz Golaszewski * This is slow, but we can't know all eeproms, so we better 5884fa882c9SBartosz Golaszewski * play safe. Specifying custom eeprom-types via platform_data 5894fa882c9SBartosz Golaszewski * is recommended anyhow. 5904fa882c9SBartosz Golaszewski */ 5914fa882c9SBartosz Golaszewski page_size = 1; 5924fa882c9SBartosz Golaszewski 5934fa882c9SBartosz Golaszewski flags = cdata->flags; 5944fa882c9SBartosz Golaszewski if (device_property_present(dev, "read-only")) 5954fa882c9SBartosz Golaszewski flags |= AT24_FLAG_READONLY; 5964fa882c9SBartosz Golaszewski if (device_property_present(dev, "no-read-rollover")) 5974fa882c9SBartosz Golaszewski flags |= AT24_FLAG_NO_RDROL; 5984fa882c9SBartosz Golaszewski 5994fa882c9SBartosz Golaszewski err = device_property_read_u32(dev, "address-width", &addrw); 6004fa882c9SBartosz Golaszewski if (!err) { 6014fa882c9SBartosz Golaszewski switch (addrw) { 6024fa882c9SBartosz Golaszewski case 8: 6034fa882c9SBartosz Golaszewski if (flags & AT24_FLAG_ADDR16) 6044fa882c9SBartosz Golaszewski dev_warn(dev, 6054fa882c9SBartosz Golaszewski "Override address width to be 8, while default is 16\n"); 6064fa882c9SBartosz Golaszewski flags &= ~AT24_FLAG_ADDR16; 6074fa882c9SBartosz Golaszewski break; 6084fa882c9SBartosz Golaszewski case 16: 6094fa882c9SBartosz Golaszewski flags |= AT24_FLAG_ADDR16; 6104fa882c9SBartosz Golaszewski break; 6114fa882c9SBartosz Golaszewski default: 6124fa882c9SBartosz Golaszewski dev_warn(dev, "Bad \"address-width\" property: %u\n", 6134fa882c9SBartosz Golaszewski addrw); 6144fa882c9SBartosz Golaszewski } 6154fa882c9SBartosz Golaszewski } 6164fa882c9SBartosz Golaszewski 6174fa882c9SBartosz Golaszewski err = device_property_read_u32(dev, "size", &byte_len); 6184fa882c9SBartosz Golaszewski if (err) 6194fa882c9SBartosz Golaszewski byte_len = cdata->byte_len; 6205195e509SWolfram Sang 62134d43fafSBartosz Golaszewski if (!i2c_fn_i2c && !i2c_fn_block) 6224fa882c9SBartosz Golaszewski page_size = 1; 623551a1266SBartosz Golaszewski 6244fa882c9SBartosz Golaszewski if (!page_size) { 625021c7d7bSBartosz Golaszewski dev_err(dev, "page_size must not be 0!\n"); 626f0ac2363SNikolay Balandin return -EINVAL; 62745efe847SWolfram Sang } 628de5db101SBartosz Golaszewski 6294fa882c9SBartosz Golaszewski if (!is_power_of_2(page_size)) 630021c7d7bSBartosz Golaszewski dev_warn(dev, "page_size looks suspicious (no power of 2)!\n"); 6315195e509SWolfram Sang 632950bcbbeSBartosz Golaszewski err = device_property_read_u32(dev, "num-addresses", &num_addresses); 633950bcbbeSBartosz Golaszewski if (err) { 6344fa882c9SBartosz Golaszewski if (flags & AT24_FLAG_TAKE8ADDR) 6355195e509SWolfram Sang num_addresses = 8; 6365195e509SWolfram Sang else 6374fa882c9SBartosz Golaszewski num_addresses = DIV_ROUND_UP(byte_len, 6384fa882c9SBartosz Golaszewski (flags & AT24_FLAG_ADDR16) ? 65536 : 256); 639950bcbbeSBartosz Golaszewski } 6405195e509SWolfram Sang 6414fa882c9SBartosz Golaszewski if ((flags & AT24_FLAG_SERIAL) && (flags & AT24_FLAG_MAC)) { 642551a1266SBartosz Golaszewski dev_err(dev, 643551a1266SBartosz Golaszewski "invalid device data - cannot have both AT24_FLAG_SERIAL & AT24_FLAG_MAC."); 644551a1266SBartosz Golaszewski return -EINVAL; 645551a1266SBartosz Golaszewski } 646551a1266SBartosz Golaszewski 647eef69398SBartosz Golaszewski regmap_config.val_bits = 8; 6484fa882c9SBartosz Golaszewski regmap_config.reg_bits = (flags & AT24_FLAG_ADDR16) ? 16 : 8; 649d154316dSBartosz Golaszewski regmap_config.disable_locking = true; 6505c015258SHeiner Kallweit 651551a1266SBartosz Golaszewski regmap = devm_regmap_init_i2c(client, ®map_config); 652551a1266SBartosz Golaszewski if (IS_ERR(regmap)) 653551a1266SBartosz Golaszewski return PTR_ERR(regmap); 654551a1266SBartosz Golaszewski 65511288b7cSBartosz Golaszewski at24_size = sizeof(*at24) + num_addresses * sizeof(struct at24_client); 65611288b7cSBartosz Golaszewski at24 = devm_kzalloc(dev, at24_size, GFP_KERNEL); 657f0ac2363SNikolay Balandin if (!at24) 658f0ac2363SNikolay Balandin return -ENOMEM; 6595195e509SWolfram Sang 6605195e509SWolfram Sang mutex_init(&at24->lock); 6614fa882c9SBartosz Golaszewski at24->byte_len = byte_len; 6624fa882c9SBartosz Golaszewski at24->page_size = page_size; 6634fa882c9SBartosz Golaszewski at24->flags = flags; 6645195e509SWolfram Sang at24->num_addresses = num_addresses; 6654fa882c9SBartosz Golaszewski at24->offset_adj = at24_get_offset_adj(flags, byte_len); 666551a1266SBartosz Golaszewski at24->client[0].client = client; 667551a1266SBartosz Golaszewski at24->client[0].regmap = regmap; 6685195e509SWolfram Sang 669021c7d7bSBartosz Golaszewski at24->wp_gpio = devm_gpiod_get_optional(dev, "wp", GPIOD_OUT_HIGH); 6706ce261e8SBartosz Golaszewski if (IS_ERR(at24->wp_gpio)) 6716ce261e8SBartosz Golaszewski return PTR_ERR(at24->wp_gpio); 6726ce261e8SBartosz Golaszewski 6734fa882c9SBartosz Golaszewski writable = !(flags & AT24_FLAG_READONLY); 6745195e509SWolfram Sang if (writable) { 675ec3c2d51SBartosz Golaszewski at24->write_max = min_t(unsigned int, 6764fa882c9SBartosz Golaszewski page_size, at24_io_limit); 67734d43fafSBartosz Golaszewski if (!i2c_fn_i2c && at24->write_max > I2C_SMBUS_BLOCK_MAX) 678a23727cbSHeiner Kallweit at24->write_max = I2C_SMBUS_BLOCK_MAX; 6795195e509SWolfram Sang } 6805195e509SWolfram Sang 6815195e509SWolfram Sang /* use dummy devices for multiple-address chips */ 6825195e509SWolfram Sang for (i = 1; i < num_addresses; i++) { 68373b0d922SBartosz Golaszewski err = at24_make_dummy_client(at24, i, ®map_config); 684e7308628SBartosz Golaszewski if (err) 68573b0d922SBartosz Golaszewski return err; 6865c015258SHeiner Kallweit } 6875195e509SWolfram Sang 68800f0ea70SBartosz Golaszewski i2c_set_clientdata(client, at24); 68900f0ea70SBartosz Golaszewski 69098e82010SDivagar Mohandass /* enable runtime pm */ 691021c7d7bSBartosz Golaszewski pm_runtime_set_active(dev); 692021c7d7bSBartosz Golaszewski pm_runtime_enable(dev); 69398e82010SDivagar Mohandass 69400f0ea70SBartosz Golaszewski /* 69500f0ea70SBartosz Golaszewski * Perform a one-byte test read to verify that the 69600f0ea70SBartosz Golaszewski * chip is functional. 69700f0ea70SBartosz Golaszewski */ 69800f0ea70SBartosz Golaszewski err = at24_read(at24, 0, &test_byte, 1); 699021c7d7bSBartosz Golaszewski pm_runtime_idle(dev); 70000f0ea70SBartosz Golaszewski if (err) { 70100f0ea70SBartosz Golaszewski err = -ENODEV; 702e7308628SBartosz Golaszewski goto err_runtime_pm; 70300f0ea70SBartosz Golaszewski } 70400f0ea70SBartosz Golaszewski 705021c7d7bSBartosz Golaszewski nvmem_config.name = dev_name(dev); 706021c7d7bSBartosz Golaszewski nvmem_config.dev = dev; 7078cdc4e7eSBartosz Golaszewski nvmem_config.read_only = !writable; 7088cdc4e7eSBartosz Golaszewski nvmem_config.root_only = true; 7098cdc4e7eSBartosz Golaszewski nvmem_config.owner = THIS_MODULE; 7108cdc4e7eSBartosz Golaszewski nvmem_config.compat = true; 711021c7d7bSBartosz Golaszewski nvmem_config.base_dev = dev; 7128cdc4e7eSBartosz Golaszewski nvmem_config.reg_read = at24_read; 7138cdc4e7eSBartosz Golaszewski nvmem_config.reg_write = at24_write; 7148cdc4e7eSBartosz Golaszewski nvmem_config.priv = at24; 7158cdc4e7eSBartosz Golaszewski nvmem_config.stride = 1; 7168cdc4e7eSBartosz Golaszewski nvmem_config.word_size = 1; 7174fa882c9SBartosz Golaszewski nvmem_config.size = byte_len; 71857d15550SAndrew Lunn 719bbe69841SBartosz Golaszewski at24->nvmem = devm_nvmem_register(dev, &nvmem_config); 72057d15550SAndrew Lunn if (IS_ERR(at24->nvmem)) { 72157d15550SAndrew Lunn err = PTR_ERR(at24->nvmem); 722e7308628SBartosz Golaszewski goto err_runtime_pm; 72357d15550SAndrew Lunn } 7245195e509SWolfram Sang 725021c7d7bSBartosz Golaszewski dev_info(dev, "%u byte %s EEPROM, %s, %u bytes/write\n", 7264fa882c9SBartosz Golaszewski byte_len, client->name, 7279ed030d7SWolfram Sang writable ? "writable" : "read-only", at24->write_max); 7285195e509SWolfram Sang 7295195e509SWolfram Sang return 0; 7305195e509SWolfram Sang 731e7308628SBartosz Golaszewski err_runtime_pm: 732021c7d7bSBartosz Golaszewski pm_runtime_disable(dev); 73398e82010SDivagar Mohandass 7345195e509SWolfram Sang return err; 7355195e509SWolfram Sang } 7365195e509SWolfram Sang 737486a5c28SBill Pemberton static int at24_remove(struct i2c_client *client) 7385195e509SWolfram Sang { 73998e82010SDivagar Mohandass pm_runtime_disable(&client->dev); 74098e82010SDivagar Mohandass pm_runtime_set_suspended(&client->dev); 74198e82010SDivagar Mohandass 7425195e509SWolfram Sang return 0; 7435195e509SWolfram Sang } 7445195e509SWolfram Sang 7455195e509SWolfram Sang static struct i2c_driver at24_driver = { 7465195e509SWolfram Sang .driver = { 7475195e509SWolfram Sang .name = "at24", 7487f2a2f0dSJavier Martinez Canillas .of_match_table = at24_of_match, 74940d8edc9SAndy Shevchenko .acpi_match_table = ACPI_PTR(at24_acpi_ids), 7505195e509SWolfram Sang }, 75148b6a7d1SBartosz Golaszewski .probe_new = at24_probe, 7522d6bed9cSBill Pemberton .remove = at24_remove, 7535195e509SWolfram Sang .id_table = at24_ids, 7545195e509SWolfram Sang }; 7555195e509SWolfram Sang 7565195e509SWolfram Sang static int __init at24_init(void) 7575195e509SWolfram Sang { 758ec3c2d51SBartosz Golaszewski if (!at24_io_limit) { 759ec3c2d51SBartosz Golaszewski pr_err("at24: at24_io_limit must not be 0!\n"); 76045efe847SWolfram Sang return -EINVAL; 76145efe847SWolfram Sang } 76245efe847SWolfram Sang 763ec3c2d51SBartosz Golaszewski at24_io_limit = rounddown_pow_of_two(at24_io_limit); 7645195e509SWolfram Sang return i2c_add_driver(&at24_driver); 7655195e509SWolfram Sang } 7665195e509SWolfram Sang module_init(at24_init); 7675195e509SWolfram Sang 7685195e509SWolfram Sang static void __exit at24_exit(void) 7695195e509SWolfram Sang { 7705195e509SWolfram Sang i2c_del_driver(&at24_driver); 7715195e509SWolfram Sang } 7725195e509SWolfram Sang module_exit(at24_exit); 7735195e509SWolfram Sang 7745195e509SWolfram Sang MODULE_DESCRIPTION("Driver for most I2C EEPROMs"); 7755195e509SWolfram Sang MODULE_AUTHOR("David Brownell and Wolfram Sang"); 7765195e509SWolfram Sang MODULE_LICENSE("GPL"); 777