// SPDX-License-Identifier: GPL-2.0-or-later /* * at24.c - handle most I2C EEPROMs * * Copyright (C) 2005-2007 David Brownell * Copyright (C) 2008 Wolfram Sang, Pengutronix */ #include <linux/acpi.h> #include <linux/bitops.h> #include <linux/capability.h> #include <linux/delay.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/jiffies.h> #include <linux/kernel.h> #include <linux/mod_devicetable.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/nvmem-provider.h> #include <linux/of_device.h> #include <linux/pm_runtime.h> #include <linux/property.h> #include <linux/regmap.h> #include <linux/regulator/consumer.h> #include <linux/slab.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 regulator *vcc_reg; <------>void (*read_post)(unsigned int off, char *buf, size_t count); <------>/* <------> * 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; <------>void (*read_post)(unsigned int off, char *buf, size_t count); }; #define AT24_CHIP_DATA(_name, _len, _flags) \ <------>static const struct at24_chip_data _name = { \ <------><------>.byte_len = _len, .flags = _flags, \ <------>} #define AT24_CHIP_DATA_CB(_name, _len, _flags, _read_post) \ <------>static const struct at24_chip_data _name = { \ <------><------>.byte_len = _len, .flags = _flags, \ <------><------>.read_post = _read_post, \ <------>} static void at24_read_post_vaio(unsigned int off, char *buf, size_t count) { <------>int i; <------>if (capable(CAP_SYS_ADMIN)) <------><------>return; <------>/* <------> * Hide VAIO private settings to regular users: <------> * - BIOS passwords: bytes 0x00 to 0x0f <------> * - UUID: bytes 0x10 to 0x1f <------> * - Serial number: 0xc0 to 0xdf <------> */ <------>for (i = 0; i < count; i++) { <------><------>if ((off + i <= 0x1f) || <------><------> (off + i >= 0xc0 && off + i <= 0xdf)) <------><------><------>buf[i] = 0; <------>} } /* 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); /* 24c02_vaio is a 24c02 on some Sony laptops */ AT24_CHIP_DATA_CB(at24_data_24c02_vaio, 2048 / 8, <------>AT24_FLAG_READONLY | AT24_FLAG_IRUGO, <------>at24_read_post_vaio); 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 }, <------>{ "24c02-vaio", (kernel_ulong_t)&at24_data_24c02_vaio }, <------>{ "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 __maybe_unused at24_acpi_ids[] = { <------>{ "INT3499", (kernel_ulong_t)&at24_data_INT3499 }, <------>{ "TPF0001", (kernel_ulong_t)&at24_data_24c1024 }, <------>{ /* 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 i, 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); <------>for (i = 0; count; i += ret, count -= ret) { <------><------>ret = at24_regmap_read(at24, buf + i, off + i, count); <------><------>if (ret < 0) { <------><------><------>mutex_unlock(&at24->lock); <------><------><------>pm_runtime_put(dev); <------><------><------>return ret; <------><------>} <------>} <------>mutex_unlock(&at24->lock); <------>pm_runtime_put(dev); <------>if (unlikely(at24->read_post)) <------><------>at24->read_post(off, buf, i); <------>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); <------>while (count) { <------><------>ret = at24_regmap_write(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 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 int at24_make_dummy_client(struct at24_data *at24, unsigned int index, <------><------><------><------> struct regmap_config *regmap_config) { <------>struct i2c_client *base_client, *dummy_client; <------>struct regmap *regmap; <------>struct device *dev; <------>base_client = at24->client[0].client; <------>dev = &base_client->dev; <------>dummy_client = devm_i2c_new_dummy_device(dev, base_client->adapter, <------><------><------><------><------><------> base_client->addr + index); <------>if (IS_ERR(dummy_client)) <------><------>return PTR_ERR(dummy_client); <------>regmap = devm_regmap_init_i2c(dummy_client, regmap_config); <------>if (IS_ERR(regmap)) <------><------>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; <------>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 device tree <------><------> * or properties 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 = devm_kzalloc(dev, struct_size(at24, client, num_addresses), <------><------><------> GFP_KERNEL); <------>if (!at24) <------><------>return -ENOMEM; <------>mutex_init(&at24->lock); <------>at24->byte_len = byte_len; <------>at24->page_size = page_size; <------>at24->flags = flags; <------>at24->read_post = cdata->read_post; <------>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->vcc_reg = devm_regulator_get(dev, "vcc"); <------>if (IS_ERR(at24->vcc_reg)) <------><------>return PTR_ERR(at24->vcc_reg); <------>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) <------><------><------>return err; <------>} <------>/* <------> * We initialize nvmem_config.id to NVMEM_DEVID_AUTO even if the <------> * label property is set as some platform can have multiple eeproms <------> * with same label and we can not register each of those with same <------> * label. Failing to register those eeproms trigger cascade failure <------> * on such platform. <------> */ <------>nvmem_config.id = NVMEM_DEVID_AUTO; <------>if (device_property_present(dev, "label")) { <------><------>err = device_property_read_string(dev, "label", <------><------><------><------><------><------> &nvmem_config.name); <------><------>if (err) <------><------><------>return err; <------>} else { <------><------>nvmem_config.name = dev_name(dev); <------>} <------>nvmem_config.type = NVMEM_TYPE_EEPROM; <------>nvmem_config.dev = dev; <------>nvmem_config.read_only = !writable; <------>nvmem_config.root_only = !(flags & AT24_FLAG_IRUGO); <------>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; <------>i2c_set_clientdata(client, at24); <------>err = regulator_enable(at24->vcc_reg); <------>if (err) { <------><------>dev_err(dev, "Failed to enable vcc regulator\n"); <------><------>return err; <------>} <------>/* enable runtime pm */ <------>pm_runtime_set_active(dev); <------>pm_runtime_enable(dev); <------>at24->nvmem = devm_nvmem_register(dev, &nvmem_config); <------>if (IS_ERR(at24->nvmem)) { <------><------>pm_runtime_disable(dev); <------><------>if (!pm_runtime_status_suspended(dev)) <------><------><------>regulator_disable(at24->vcc_reg); <------><------>return PTR_ERR(at24->nvmem); <------>} <------>/* <------> * Perform a one-byte test read to verify that the <------> * chip is functional. <------> */ <------>err = at24_read(at24, 0, &test_byte, 1); <------>if (err) { <------><------>pm_runtime_disable(dev); <------><------>if (!pm_runtime_status_suspended(dev)) <------><------><------>regulator_disable(at24->vcc_reg); <------><------>return -ENODEV; <------>} <------>pm_runtime_idle(dev); <------>if (writable) <------><------>dev_info(dev, "%u byte %s EEPROM, writable, %u bytes/write\n", <------><------><------> byte_len, client->name, at24->write_max); <------>else <------><------>dev_info(dev, "%u byte %s EEPROM, read-only\n", <------><------><------> byte_len, client->name); <------>return 0; } static int at24_remove(struct i2c_client *client) { <------>struct at24_data *at24 = i2c_get_clientdata(client); <------>pm_runtime_disable(&client->dev); <------>if (!pm_runtime_status_suspended(&client->dev)) <------><------>regulator_disable(at24->vcc_reg); <------>pm_runtime_set_suspended(&client->dev); <------>return 0; } static int __maybe_unused at24_suspend(struct device *dev) { <------>struct i2c_client *client = to_i2c_client(dev); <------>struct at24_data *at24 = i2c_get_clientdata(client); <------>return regulator_disable(at24->vcc_reg); } static int __maybe_unused at24_resume(struct device *dev) { <------>struct i2c_client *client = to_i2c_client(dev); <------>struct at24_data *at24 = i2c_get_clientdata(client); <------>return regulator_enable(at24->vcc_reg); } static const struct dev_pm_ops at24_pm_ops = { <------>SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, <------><------><------><------>pm_runtime_force_resume) <------>SET_RUNTIME_PM_OPS(at24_suspend, at24_resume, NULL) }; static struct i2c_driver at24_driver = { <------>.driver = { <------><------>.name = "at24", <------><------>.pm = &at24_pm_ops, <------><------>.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");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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