| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * at24.c - handle most I2C EEPROMs |
| * |
| * Copyright (C) 2005-2007 David Brownell |
| * Copyright (C) 2008 Wolfram Sang, Pengutronix |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/of_device.h> |
| #include <linux/slab.h> |
| #include <linux/delay.h> |
| #include <linux/mutex.h> |
| #include <linux/mod_devicetable.h> |
| #include <linux/log2.h> |
| #include <linux/bitops.h> |
| #include <linux/jiffies.h> |
| #include <linux/property.h> |
| #include <linux/acpi.h> |
| #include <linux/i2c.h> |
| #include <linux/nvmem-provider.h> |
| #include <linux/regmap.h> |
| #include <linux/pm_runtime.h> |
| #include <linux/gpio/consumer.h> |
| |
| /* Address pointer is 16 bit. */ |
| #define AT24_FLAG_ADDR16 BIT(7) |
| /* sysfs-entry will be read-only. */ |
| #define AT24_FLAG_READONLY BIT(6) |
| /* sysfs-entry will be world-readable. */ |
| #define AT24_FLAG_IRUGO BIT(5) |
| /* Take always 8 addresses (24c00). */ |
| #define AT24_FLAG_TAKE8ADDR BIT(4) |
| /* Factory-programmed serial number. */ |
| #define AT24_FLAG_SERIAL BIT(3) |
| /* Factory-programmed mac address. */ |
| #define AT24_FLAG_MAC BIT(2) |
| /* Does not auto-rollover reads to the next slave address. */ |
| #define AT24_FLAG_NO_RDROL BIT(1) |
| |
| /* |
| * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable. |
| * Differences between different vendor product lines (like Atmel AT24C or |
| * MicroChip 24LC, etc) won't much matter for typical read/write access. |
| * There are also I2C RAM chips, likewise interchangeable. One example |
| * would be the PCF8570, which acts like a 24c02 EEPROM (256 bytes). |
| * |
| * However, misconfiguration can lose data. "Set 16-bit memory address" |
| * to a part with 8-bit addressing will overwrite data. Writing with too |
| * big a page size also loses data. And it's not safe to assume that the |
| * conventional addresses 0x50..0x57 only hold eeproms; a PCF8563 RTC |
| * uses 0x51, for just one example. |
| * |
| * Accordingly, explicit board-specific configuration data should be used |
| * in almost all cases. (One partial exception is an SMBus used to access |
| * "SPD" data for DRAM sticks. Those only use 24c02 EEPROMs.) |
| * |
| * So this driver uses "new style" I2C driver binding, expecting to be |
| * told what devices exist. That may be in arch/X/mach-Y/board-Z.c or |
| * similar kernel-resident tables; or, configuration data coming from |
| * a bootloader. |
| * |
| * Other than binding model, current differences from "eeprom" driver are |
| * that this one handles write access and isn't restricted to 24c02 devices. |
| * It also handles larger devices (32 kbit and up) with two-byte addresses, |
| * which won't work on pure SMBus systems. |
| */ |
| |
| struct at24_client { |
| struct i2c_client *client; |
| struct regmap *regmap; |
| }; |
| |
| struct at24_data { |
| /* |
| * Lock protects against activities from other Linux tasks, |
| * but not from changes by other I2C masters. |
| */ |
| struct mutex lock; |
| |
| unsigned int write_max; |
| unsigned int num_addresses; |
| unsigned int offset_adj; |
| |
| u32 byte_len; |
| u16 page_size; |
| u8 flags; |
| |
| struct nvmem_device *nvmem; |
| |
| struct gpio_desc *wp_gpio; |
| |
| /* |
| * Some chips tie up multiple I2C addresses; dummy devices reserve |
| * them for us, and we'll use them with SMBus calls. |
| */ |
| struct at24_client client[]; |
| }; |
| |
| /* |
| * This parameter is to help this driver avoid blocking other drivers out |
| * of I2C for potentially troublesome amounts of time. With a 100 kHz I2C |
| * clock, one 256 byte read takes about 1/43 second which is excessive; |
| * but the 1/170 second it takes at 400 kHz may be quite reasonable; and |
| * at 1 MHz (Fm+) a 1/430 second delay could easily be invisible. |
| * |
| * This value is forced to be a power of two so that writes align on pages. |
| */ |
| static unsigned int at24_io_limit = 128; |
| module_param_named(io_limit, at24_io_limit, uint, 0); |
| MODULE_PARM_DESC(at24_io_limit, "Maximum bytes per I/O (default 128)"); |
| |
| /* |
| * Specs often allow 5 msec for a page write, sometimes 20 msec; |
| * it's important to recover from write timeouts. |
| */ |
| static unsigned int at24_write_timeout = 25; |
| module_param_named(write_timeout, at24_write_timeout, uint, 0); |
| MODULE_PARM_DESC(at24_write_timeout, "Time (in ms) to try writes (default 25)"); |
| |
| struct at24_chip_data { |
| u32 byte_len; |
| u8 flags; |
| }; |
| |
| #define AT24_CHIP_DATA(_name, _len, _flags) \ |
| static const struct at24_chip_data _name = { \ |
| .byte_len = _len, .flags = _flags, \ |
| } |
| |
| /* needs 8 addresses as A0-A2 are ignored */ |
| AT24_CHIP_DATA(at24_data_24c00, 128 / 8, AT24_FLAG_TAKE8ADDR); |
| /* old variants can't be handled with this generic entry! */ |
| AT24_CHIP_DATA(at24_data_24c01, 1024 / 8, 0); |
| AT24_CHIP_DATA(at24_data_24cs01, 16, |
| AT24_FLAG_SERIAL | AT24_FLAG_READONLY); |
| AT24_CHIP_DATA(at24_data_24c02, 2048 / 8, 0); |
| AT24_CHIP_DATA(at24_data_24cs02, 16, |
| AT24_FLAG_SERIAL | AT24_FLAG_READONLY); |
| AT24_CHIP_DATA(at24_data_24mac402, 48 / 8, |
| AT24_FLAG_MAC | AT24_FLAG_READONLY); |
| AT24_CHIP_DATA(at24_data_24mac602, 64 / 8, |
| AT24_FLAG_MAC | AT24_FLAG_READONLY); |
| /* spd is a 24c02 in memory DIMMs */ |
| AT24_CHIP_DATA(at24_data_spd, 2048 / 8, |
| AT24_FLAG_READONLY | AT24_FLAG_IRUGO); |
| AT24_CHIP_DATA(at24_data_24c04, 4096 / 8, 0); |
| AT24_CHIP_DATA(at24_data_24cs04, 16, |
| AT24_FLAG_SERIAL | AT24_FLAG_READONLY); |
| /* 24rf08 quirk is handled at i2c-core */ |
| AT24_CHIP_DATA(at24_data_24c08, 8192 / 8, 0); |
| AT24_CHIP_DATA(at24_data_24cs08, 16, |
| AT24_FLAG_SERIAL | AT24_FLAG_READONLY); |
| AT24_CHIP_DATA(at24_data_24c16, 16384 / 8, 0); |
| AT24_CHIP_DATA(at24_data_24cs16, 16, |
| AT24_FLAG_SERIAL | AT24_FLAG_READONLY); |
| AT24_CHIP_DATA(at24_data_24c32, 32768 / 8, AT24_FLAG_ADDR16); |
| AT24_CHIP_DATA(at24_data_24cs32, 16, |
| AT24_FLAG_ADDR16 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); |
| AT24_CHIP_DATA(at24_data_24c64, 65536 / 8, AT24_FLAG_ADDR16); |
| AT24_CHIP_DATA(at24_data_24cs64, 16, |
| AT24_FLAG_ADDR16 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); |
| AT24_CHIP_DATA(at24_data_24c128, 131072 / 8, AT24_FLAG_ADDR16); |
| AT24_CHIP_DATA(at24_data_24c256, 262144 / 8, AT24_FLAG_ADDR16); |
| AT24_CHIP_DATA(at24_data_24c512, 524288 / 8, AT24_FLAG_ADDR16); |
| AT24_CHIP_DATA(at24_data_24c1024, 1048576 / 8, AT24_FLAG_ADDR16); |
| AT24_CHIP_DATA(at24_data_24c2048, 2097152 / 8, AT24_FLAG_ADDR16); |
| /* identical to 24c08 ? */ |
| AT24_CHIP_DATA(at24_data_INT3499, 8192 / 8, 0); |
| |
| static const struct i2c_device_id at24_ids[] = { |
| { "24c00", (kernel_ulong_t)&at24_data_24c00 }, |
| { "24c01", (kernel_ulong_t)&at24_data_24c01 }, |
| { "24cs01", (kernel_ulong_t)&at24_data_24cs01 }, |
| { "24c02", (kernel_ulong_t)&at24_data_24c02 }, |
| { "24cs02", (kernel_ulong_t)&at24_data_24cs02 }, |
| { "24mac402", (kernel_ulong_t)&at24_data_24mac402 }, |
| { "24mac602", (kernel_ulong_t)&at24_data_24mac602 }, |
| { "spd", (kernel_ulong_t)&at24_data_spd }, |
| { "24c04", (kernel_ulong_t)&at24_data_24c04 }, |
| { "24cs04", (kernel_ulong_t)&at24_data_24cs04 }, |
| { "24c08", (kernel_ulong_t)&at24_data_24c08 }, |
| { "24cs08", (kernel_ulong_t)&at24_data_24cs08 }, |
| { "24c16", (kernel_ulong_t)&at24_data_24c16 }, |
| { "24cs16", (kernel_ulong_t)&at24_data_24cs16 }, |
| { "24c32", (kernel_ulong_t)&at24_data_24c32 }, |
| { "24cs32", (kernel_ulong_t)&at24_data_24cs32 }, |
| { "24c64", (kernel_ulong_t)&at24_data_24c64 }, |
| { "24cs64", (kernel_ulong_t)&at24_data_24cs64 }, |
| { "24c128", (kernel_ulong_t)&at24_data_24c128 }, |
| { "24c256", (kernel_ulong_t)&at24_data_24c256 }, |
| { "24c512", (kernel_ulong_t)&at24_data_24c512 }, |
| { "24c1024", (kernel_ulong_t)&at24_data_24c1024 }, |
| { "24c2048", (kernel_ulong_t)&at24_data_24c2048 }, |
| { "at24", 0 }, |
| { /* END OF LIST */ } |
| }; |
| MODULE_DEVICE_TABLE(i2c, at24_ids); |
| |
| static const struct of_device_id at24_of_match[] = { |
| { .compatible = "atmel,24c00", .data = &at24_data_24c00 }, |
| { .compatible = "atmel,24c01", .data = &at24_data_24c01 }, |
| { .compatible = "atmel,24cs01", .data = &at24_data_24cs01 }, |
| { .compatible = "atmel,24c02", .data = &at24_data_24c02 }, |
| { .compatible = "atmel,24cs02", .data = &at24_data_24cs02 }, |
| { .compatible = "atmel,24mac402", .data = &at24_data_24mac402 }, |
| { .compatible = "atmel,24mac602", .data = &at24_data_24mac602 }, |
| { .compatible = "atmel,spd", .data = &at24_data_spd }, |
| { .compatible = "atmel,24c04", .data = &at24_data_24c04 }, |
| { .compatible = "atmel,24cs04", .data = &at24_data_24cs04 }, |
| { .compatible = "atmel,24c08", .data = &at24_data_24c08 }, |
| { .compatible = "atmel,24cs08", .data = &at24_data_24cs08 }, |
| { .compatible = "atmel,24c16", .data = &at24_data_24c16 }, |
| { .compatible = "atmel,24cs16", .data = &at24_data_24cs16 }, |
| { .compatible = "atmel,24c32", .data = &at24_data_24c32 }, |
| { .compatible = "atmel,24cs32", .data = &at24_data_24cs32 }, |
| { .compatible = "atmel,24c64", .data = &at24_data_24c64 }, |
| { .compatible = "atmel,24cs64", .data = &at24_data_24cs64 }, |
| { .compatible = "atmel,24c128", .data = &at24_data_24c128 }, |
| { .compatible = "atmel,24c256", .data = &at24_data_24c256 }, |
| { .compatible = "atmel,24c512", .data = &at24_data_24c512 }, |
| { .compatible = "atmel,24c1024", .data = &at24_data_24c1024 }, |
| { .compatible = "atmel,24c2048", .data = &at24_data_24c2048 }, |
| { /* END OF LIST */ }, |
| }; |
| MODULE_DEVICE_TABLE(of, at24_of_match); |
| |
| static const struct acpi_device_id at24_acpi_ids[] = { |
| { "INT3499", (kernel_ulong_t)&at24_data_INT3499 }, |
| { /* END OF LIST */ } |
| }; |
| MODULE_DEVICE_TABLE(acpi, at24_acpi_ids); |
| |
| /* |
| * This routine supports chips which consume multiple I2C addresses. It |
| * computes the addressing information to be used for a given r/w request. |
| * Assumes that sanity checks for offset happened at sysfs-layer. |
| * |
| * Slave address and byte offset derive from the offset. Always |
| * set the byte address; on a multi-master board, another master |
| * may have changed the chip's "current" address pointer. |
| */ |
| static struct at24_client *at24_translate_offset(struct at24_data *at24, |
| unsigned int *offset) |
| { |
| unsigned int i; |
| |
| if (at24->flags & AT24_FLAG_ADDR16) { |
| i = *offset >> 16; |
| *offset &= 0xffff; |
| } else { |
| i = *offset >> 8; |
| *offset &= 0xff; |
| } |
| |
| return &at24->client[i]; |
| } |
| |
| static struct device *at24_base_client_dev(struct at24_data *at24) |
| { |
| return &at24->client[0].client->dev; |
| } |
| |
| static size_t at24_adjust_read_count(struct at24_data *at24, |
| unsigned int offset, size_t count) |
| { |
| unsigned int bits; |
| size_t remainder; |
| |
| /* |
| * In case of multi-address chips that don't rollover reads to |
| * the next slave address: truncate the count to the slave boundary, |
| * so that the read never straddles slaves. |
| */ |
| if (at24->flags & AT24_FLAG_NO_RDROL) { |
| bits = (at24->flags & AT24_FLAG_ADDR16) ? 16 : 8; |
| remainder = BIT(bits) - offset; |
| if (count > remainder) |
| count = remainder; |
| } |
| |
| if (count > at24_io_limit) |
| count = at24_io_limit; |
| |
| return count; |
| } |
| |
| static ssize_t at24_regmap_read(struct at24_data *at24, char *buf, |
| unsigned int offset, size_t count) |
| { |
| unsigned long timeout, read_time; |
| struct at24_client *at24_client; |
| struct i2c_client *client; |
| struct regmap *regmap; |
| int ret; |
| |
| at24_client = at24_translate_offset(at24, &offset); |
| regmap = at24_client->regmap; |
| client = at24_client->client; |
| count = at24_adjust_read_count(at24, offset, count); |
| |
| /* adjust offset for mac and serial read ops */ |
| offset += at24->offset_adj; |
| |
| timeout = jiffies + msecs_to_jiffies(at24_write_timeout); |
| do { |
| /* |
| * The timestamp shall be taken before the actual operation |
| * to avoid a premature timeout in case of high CPU load. |
| */ |
| read_time = jiffies; |
| |
| ret = regmap_bulk_read(regmap, offset, buf, count); |
| dev_dbg(&client->dev, "read %zu@%d --> %d (%ld)\n", |
| count, offset, ret, jiffies); |
| if (!ret) |
| return count; |
| |
| usleep_range(1000, 1500); |
| } while (time_before(read_time, timeout)); |
| |
| return -ETIMEDOUT; |
| } |
| |
| /* |
| * Note that if the hardware write-protect pin is pulled high, the whole |
| * chip is normally write protected. But there are plenty of product |
| * variants here, including OTP fuses and partial chip protect. |
| * |
| * We only use page mode writes; the alternative is sloooow. These routines |
| * write at most one page. |
| */ |
| |
| static size_t at24_adjust_write_count(struct at24_data *at24, |
| unsigned int offset, size_t count) |
| { |
| unsigned int next_page; |
| |
| /* write_max is at most a page */ |
| if (count > at24->write_max) |
| count = at24->write_max; |
| |
| /* Never roll over backwards, to the start of this page */ |
| next_page = roundup(offset + 1, at24->page_size); |
| if (offset + count > next_page) |
| count = next_page - offset; |
| |
| return count; |
| } |
| |
| static ssize_t at24_regmap_write(struct at24_data *at24, const char *buf, |
| unsigned int offset, size_t count) |
| { |
| unsigned long timeout, write_time; |
| struct at24_client *at24_client; |
| struct i2c_client *client; |
| struct regmap *regmap; |
| int ret; |
| |
| at24_client = at24_translate_offset(at24, &offset); |
| regmap = at24_client->regmap; |
| client = at24_client->client; |
| count = at24_adjust_write_count(at24, offset, count); |
| timeout = jiffies + msecs_to_jiffies(at24_write_timeout); |
| |
| do { |
| /* |
| * The timestamp shall be taken before the actual operation |
| * to avoid a premature timeout in case of high CPU load. |
| */ |
| write_time = jiffies; |
| |
| ret = regmap_bulk_write(regmap, offset, buf, count); |
| dev_dbg(&client->dev, "write %zu@%d --> %d (%ld)\n", |
| count, offset, ret, jiffies); |
| if (!ret) |
| return count; |
| |
| usleep_range(1000, 1500); |
| } while (time_before(write_time, timeout)); |
| |
| return -ETIMEDOUT; |
| } |
| |
| static int at24_read(void *priv, unsigned int off, void *val, size_t count) |
| { |
| struct at24_data *at24; |
| struct device *dev; |
| char *buf = val; |
| int ret; |
| |
| at24 = priv; |
| dev = at24_base_client_dev(at24); |
| |
| if (unlikely(!count)) |
| return count; |
| |
| if (off + count > at24->byte_len) |
| return -EINVAL; |
| |
| ret = pm_runtime_get_sync(dev); |
| if (ret < 0) { |
| pm_runtime_put_noidle(dev); |
| return ret; |
| } |
| |
| /* |
| * Read data from chip, protecting against concurrent updates |
| * from this host, but not from other I2C masters. |
| */ |
| mutex_lock(&at24->lock); |
| |
| while (count) { |
| ret = at24_regmap_read(at24, buf, off, count); |
| if (ret < 0) { |
| mutex_unlock(&at24->lock); |
| pm_runtime_put(dev); |
| return ret; |
| } |
| buf += ret; |
| off += ret; |
| count -= ret; |
| } |
| |
| mutex_unlock(&at24->lock); |
| |
| pm_runtime_put(dev); |
| |
| return 0; |
| } |
| |
| static int at24_write(void *priv, unsigned int off, void *val, size_t count) |
| { |
| struct at24_data *at24; |
| struct device *dev; |
| char *buf = val; |
| int ret; |
| |
| at24 = priv; |
| dev = at24_base_client_dev(at24); |
| |
| if (unlikely(!count)) |
| return -EINVAL; |
| |
| if (off + count > at24->byte_len) |
| return -EINVAL; |
| |
| ret = pm_runtime_get_sync(dev); |
| if (ret < 0) { |
| pm_runtime_put_noidle(dev); |
| return ret; |
| } |
| |
| /* |
| * Write data to chip, protecting against concurrent updates |
| * from this host, but not from other I2C masters. |
| */ |
| mutex_lock(&at24->lock); |
| gpiod_set_value_cansleep(at24->wp_gpio, 0); |
| |
| while (count) { |
| ret = at24_regmap_write(at24, buf, off, count); |
| if (ret < 0) { |
| gpiod_set_value_cansleep(at24->wp_gpio, 1); |
| mutex_unlock(&at24->lock); |
| pm_runtime_put(dev); |
| return ret; |
| } |
| buf += ret; |
| off += ret; |
| count -= ret; |
| } |
| |
| gpiod_set_value_cansleep(at24->wp_gpio, 1); |
| mutex_unlock(&at24->lock); |
| |
| pm_runtime_put(dev); |
| |
| return 0; |
| } |
| |
| static const struct at24_chip_data *at24_get_chip_data(struct device *dev) |
| { |
| struct device_node *of_node = dev->of_node; |
| const struct at24_chip_data *cdata; |
| const struct i2c_device_id *id; |
| |
| id = i2c_match_id(at24_ids, to_i2c_client(dev)); |
| |
| /* |
| * The I2C core allows OF nodes compatibles to match against the |
| * I2C device ID table as a fallback, so check not only if an OF |
| * node is present but also if it matches an OF device ID entry. |
| */ |
| if (of_node && of_match_device(at24_of_match, dev)) |
| cdata = of_device_get_match_data(dev); |
| else if (id) |
| cdata = (void *)id->driver_data; |
| else |
| cdata = acpi_device_get_match_data(dev); |
| |
| if (!cdata) |
| return ERR_PTR(-ENODEV); |
| |
| return cdata; |
| } |
| |
| static void at24_remove_dummy_clients(struct at24_data *at24) |
| { |
| int i; |
| |
| for (i = 1; i < at24->num_addresses; i++) |
| i2c_unregister_device(at24->client[i].client); |
| } |
| |
| static int at24_make_dummy_client(struct at24_data *at24, unsigned int index, |
| struct regmap_config *regmap_config) |
| { |
| struct i2c_client *base_client, *dummy_client; |
| unsigned short int addr; |
| struct regmap *regmap; |
| struct device *dev; |
| |
| base_client = at24->client[0].client; |
| dev = &base_client->dev; |
| addr = base_client->addr + index; |
| |
| dummy_client = i2c_new_dummy(base_client->adapter, |
| base_client->addr + index); |
| if (!dummy_client) { |
| dev_err(dev, "address 0x%02x unavailable\n", addr); |
| return -EADDRINUSE; |
| } |
| |
| regmap = devm_regmap_init_i2c(dummy_client, regmap_config); |
| if (IS_ERR(regmap)) { |
| i2c_unregister_device(dummy_client); |
| return PTR_ERR(regmap); |
| } |
| |
| at24->client[index].client = dummy_client; |
| at24->client[index].regmap = regmap; |
| |
| return 0; |
| } |
| |
| static unsigned int at24_get_offset_adj(u8 flags, unsigned int byte_len) |
| { |
| if (flags & AT24_FLAG_MAC) { |
| /* EUI-48 starts from 0x9a, EUI-64 from 0x98 */ |
| return 0xa0 - byte_len; |
| } else if (flags & AT24_FLAG_SERIAL && flags & AT24_FLAG_ADDR16) { |
| /* |
| * For 16 bit address pointers, the word address must contain |
| * a '10' sequence in bits 11 and 10 regardless of the |
| * intended position of the address pointer. |
| */ |
| return 0x0800; |
| } else if (flags & AT24_FLAG_SERIAL) { |
| /* |
| * Otherwise the word address must begin with a '10' sequence, |
| * regardless of the intended address. |
| */ |
| return 0x0080; |
| } else { |
| return 0; |
| } |
| } |
| |
| static int at24_probe(struct i2c_client *client) |
| { |
| struct regmap_config regmap_config = { }; |
| struct nvmem_config nvmem_config = { }; |
| u32 byte_len, page_size, flags, addrw; |
| const struct at24_chip_data *cdata; |
| struct device *dev = &client->dev; |
| bool i2c_fn_i2c, i2c_fn_block; |
| unsigned int i, num_addresses; |
| struct at24_data *at24; |
| struct regmap *regmap; |
| size_t at24_size; |
| bool writable; |
| u8 test_byte; |
| int err; |
| |
| i2c_fn_i2c = i2c_check_functionality(client->adapter, I2C_FUNC_I2C); |
| i2c_fn_block = i2c_check_functionality(client->adapter, |
| I2C_FUNC_SMBUS_WRITE_I2C_BLOCK); |
| |
| cdata = at24_get_chip_data(dev); |
| if (IS_ERR(cdata)) |
| return PTR_ERR(cdata); |
| |
| err = device_property_read_u32(dev, "pagesize", &page_size); |
| if (err) |
| /* |
| * This is slow, but we can't know all eeproms, so we better |
| * play safe. Specifying custom eeprom-types via platform_data |
| * is recommended anyhow. |
| */ |
| page_size = 1; |
| |
| flags = cdata->flags; |
| if (device_property_present(dev, "read-only")) |
| flags |= AT24_FLAG_READONLY; |
| if (device_property_present(dev, "no-read-rollover")) |
| flags |= AT24_FLAG_NO_RDROL; |
| |
| err = device_property_read_u32(dev, "address-width", &addrw); |
| if (!err) { |
| switch (addrw) { |
| case 8: |
| if (flags & AT24_FLAG_ADDR16) |
| dev_warn(dev, |
| "Override address width to be 8, while default is 16\n"); |
| flags &= ~AT24_FLAG_ADDR16; |
| break; |
| case 16: |
| flags |= AT24_FLAG_ADDR16; |
| break; |
| default: |
| dev_warn(dev, "Bad \"address-width\" property: %u\n", |
| addrw); |
| } |
| } |
| |
| err = device_property_read_u32(dev, "size", &byte_len); |
| if (err) |
| byte_len = cdata->byte_len; |
| |
| if (!i2c_fn_i2c && !i2c_fn_block) |
| page_size = 1; |
| |
| if (!page_size) { |
| dev_err(dev, "page_size must not be 0!\n"); |
| return -EINVAL; |
| } |
| |
| if (!is_power_of_2(page_size)) |
| dev_warn(dev, "page_size looks suspicious (no power of 2)!\n"); |
| |
| err = device_property_read_u32(dev, "num-addresses", &num_addresses); |
| if (err) { |
| if (flags & AT24_FLAG_TAKE8ADDR) |
| num_addresses = 8; |
| else |
| num_addresses = DIV_ROUND_UP(byte_len, |
| (flags & AT24_FLAG_ADDR16) ? 65536 : 256); |
| } |
| |
| if ((flags & AT24_FLAG_SERIAL) && (flags & AT24_FLAG_MAC)) { |
| dev_err(dev, |
| "invalid device data - cannot have both AT24_FLAG_SERIAL & AT24_FLAG_MAC."); |
| return -EINVAL; |
| } |
| |
| regmap_config.val_bits = 8; |
| regmap_config.reg_bits = (flags & AT24_FLAG_ADDR16) ? 16 : 8; |
| regmap_config.disable_locking = true; |
| |
| regmap = devm_regmap_init_i2c(client, ®map_config); |
| if (IS_ERR(regmap)) |
| return PTR_ERR(regmap); |
| |
| at24_size = sizeof(*at24) + num_addresses * sizeof(struct at24_client); |
| at24 = devm_kzalloc(dev, at24_size, GFP_KERNEL); |
| if (!at24) |
| return -ENOMEM; |
| |
| mutex_init(&at24->lock); |
| at24->byte_len = byte_len; |
| at24->page_size = page_size; |
| at24->flags = flags; |
| at24->num_addresses = num_addresses; |
| at24->offset_adj = at24_get_offset_adj(flags, byte_len); |
| at24->client[0].client = client; |
| at24->client[0].regmap = regmap; |
| |
| at24->wp_gpio = devm_gpiod_get_optional(dev, "wp", GPIOD_OUT_HIGH); |
| if (IS_ERR(at24->wp_gpio)) |
| return PTR_ERR(at24->wp_gpio); |
| |
| writable = !(flags & AT24_FLAG_READONLY); |
| if (writable) { |
| at24->write_max = min_t(unsigned int, |
| page_size, at24_io_limit); |
| if (!i2c_fn_i2c && at24->write_max > I2C_SMBUS_BLOCK_MAX) |
| at24->write_max = I2C_SMBUS_BLOCK_MAX; |
| } |
| |
| /* use dummy devices for multiple-address chips */ |
| for (i = 1; i < num_addresses; i++) { |
| err = at24_make_dummy_client(at24, i, ®map_config); |
| if (err) { |
| at24_remove_dummy_clients(at24); |
| return err; |
| } |
| } |
| |
| i2c_set_clientdata(client, at24); |
| |
| /* enable runtime pm */ |
| pm_runtime_set_active(dev); |
| pm_runtime_enable(dev); |
| |
| /* |
| * Perform a one-byte test read to verify that the |
| * chip is functional. |
| */ |
| err = at24_read(at24, 0, &test_byte, 1); |
| pm_runtime_idle(dev); |
| if (err) { |
| err = -ENODEV; |
| goto err_clients; |
| } |
| |
| nvmem_config.name = dev_name(dev); |
| nvmem_config.dev = dev; |
| nvmem_config.read_only = !writable; |
| nvmem_config.root_only = true; |
| nvmem_config.owner = THIS_MODULE; |
| nvmem_config.compat = true; |
| nvmem_config.base_dev = dev; |
| nvmem_config.reg_read = at24_read; |
| nvmem_config.reg_write = at24_write; |
| nvmem_config.priv = at24; |
| nvmem_config.stride = 1; |
| nvmem_config.word_size = 1; |
| nvmem_config.size = byte_len; |
| |
| at24->nvmem = devm_nvmem_register(dev, &nvmem_config); |
| if (IS_ERR(at24->nvmem)) { |
| err = PTR_ERR(at24->nvmem); |
| goto err_clients; |
| } |
| |
| dev_info(dev, "%u byte %s EEPROM, %s, %u bytes/write\n", |
| byte_len, client->name, |
| writable ? "writable" : "read-only", at24->write_max); |
| |
| return 0; |
| |
| err_clients: |
| at24_remove_dummy_clients(at24); |
| pm_runtime_disable(dev); |
| |
| return err; |
| } |
| |
| static int at24_remove(struct i2c_client *client) |
| { |
| struct at24_data *at24; |
| |
| at24 = i2c_get_clientdata(client); |
| |
| at24_remove_dummy_clients(at24); |
| pm_runtime_disable(&client->dev); |
| pm_runtime_set_suspended(&client->dev); |
| |
| return 0; |
| } |
| |
| static struct i2c_driver at24_driver = { |
| .driver = { |
| .name = "at24", |
| .of_match_table = at24_of_match, |
| .acpi_match_table = ACPI_PTR(at24_acpi_ids), |
| }, |
| .probe_new = at24_probe, |
| .remove = at24_remove, |
| .id_table = at24_ids, |
| }; |
| |
| static int __init at24_init(void) |
| { |
| if (!at24_io_limit) { |
| pr_err("at24: at24_io_limit must not be 0!\n"); |
| return -EINVAL; |
| } |
| |
| at24_io_limit = rounddown_pow_of_two(at24_io_limit); |
| return i2c_add_driver(&at24_driver); |
| } |
| module_init(at24_init); |
| |
| static void __exit at24_exit(void) |
| { |
| i2c_del_driver(&at24_driver); |
| } |
| module_exit(at24_exit); |
| |
| MODULE_DESCRIPTION("Driver for most I2C EEPROMs"); |
| MODULE_AUTHOR("David Brownell and Wolfram Sang"); |
| MODULE_LICENSE("GPL"); |