From 4b364f230a5ef984818837ec7c2be0884eac191c Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Mon, 15 Jun 2009 18:01:49 +0200 Subject: i2c/chips: Move max6875 to drivers/misc/eeprom This driver only reads the user EEPROM of that chip, so we can move it to the eeprom-directory in order to further clean up (and later remove) drivers/i2c/chips. The Kconfig text was updated to match the current functionality, dropping the meanwhile obsoleted parts. Defconfigs have been adapted. Signed-off-by: Wolfram Sang Acked-by: Ben Gardner Signed-off-by: Jean Delvare --- drivers/misc/eeprom/Kconfig | 14 +++ drivers/misc/eeprom/Makefile | 1 + drivers/misc/eeprom/max6875.c | 246 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 261 insertions(+) create mode 100644 drivers/misc/eeprom/max6875.c (limited to 'drivers/misc/eeprom') diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig index 89fec052f3b..9118613af32 100644 --- a/drivers/misc/eeprom/Kconfig +++ b/drivers/misc/eeprom/Kconfig @@ -48,6 +48,20 @@ config EEPROM_LEGACY This driver can also be built as a module. If so, the module will be called eeprom. +config EEPROM_MAX6875 + tristate "Maxim MAX6874/5 power supply supervisor" + depends on I2C && EXPERIMENTAL + help + If you say yes here you get read-only support for the user EEPROM of + the Maxim MAX6874/5 EEPROM-programmable, quad power-supply + sequencer/supervisor. + + All other features of this chip should be accessed via i2c-dev. + + This driver can also be built as a module. If so, the module + will be called max6875. + + config EEPROM_93CX6 tristate "EEPROM 93CX6 support" help diff --git a/drivers/misc/eeprom/Makefile b/drivers/misc/eeprom/Makefile index 539dd8f8812..df3d68ffa9d 100644 --- a/drivers/misc/eeprom/Makefile +++ b/drivers/misc/eeprom/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_EEPROM_AT24) += at24.o obj-$(CONFIG_EEPROM_AT25) += at25.o obj-$(CONFIG_EEPROM_LEGACY) += eeprom.o +obj-$(CONFIG_EEPROM_MAX6875) += max6875.o obj-$(CONFIG_EEPROM_93CX6) += eeprom_93cx6.o diff --git a/drivers/misc/eeprom/max6875.c b/drivers/misc/eeprom/max6875.c new file mode 100644 index 00000000000..3c0c58eed34 --- /dev/null +++ b/drivers/misc/eeprom/max6875.c @@ -0,0 +1,246 @@ +/* + max6875.c - driver for MAX6874/MAX6875 + + Copyright (C) 2005 Ben Gardner + + Based on eeprom.c + + The MAX6875 has a bank of registers and two banks of EEPROM. + Address ranges are defined as follows: + * 0x0000 - 0x0046 = configuration registers + * 0x8000 - 0x8046 = configuration EEPROM + * 0x8100 - 0x82FF = user EEPROM + + This driver makes the user EEPROM available for read. + + The registers & config EEPROM should be accessed via i2c-dev. + + The MAX6875 ignores the lowest address bit, so each chip responds to + two addresses - 0x50/0x51 and 0x52/0x53. + + Note that the MAX6875 uses i2c_smbus_write_byte_data() to set the read + address, so this driver is destructive if loaded for the wrong EEPROM chip. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. +*/ + +#include +#include +#include +#include +#include +#include + +/* Do not scan - the MAX6875 access method will write to some EEPROM chips */ +static const unsigned short normal_i2c[] = { I2C_CLIENT_END }; + +/* Insmod parameters */ +I2C_CLIENT_INSMOD_1(max6875); + +/* The MAX6875 can only read/write 16 bytes at a time */ +#define SLICE_SIZE 16 +#define SLICE_BITS 4 + +/* USER EEPROM is at addresses 0x8100 - 0x82FF */ +#define USER_EEPROM_BASE 0x8100 +#define USER_EEPROM_SIZE 0x0200 +#define USER_EEPROM_SLICES 32 + +/* MAX6875 commands */ +#define MAX6875_CMD_BLK_READ 0x84 + +/* Each client has this additional data */ +struct max6875_data { + struct i2c_client *fake_client; + struct mutex update_lock; + + u32 valid; + u8 data[USER_EEPROM_SIZE]; + unsigned long last_updated[USER_EEPROM_SLICES]; +}; + +static void max6875_update_slice(struct i2c_client *client, int slice) +{ + struct max6875_data *data = i2c_get_clientdata(client); + int i, j, addr; + u8 *buf; + + if (slice >= USER_EEPROM_SLICES) + return; + + mutex_lock(&data->update_lock); + + buf = &data->data[slice << SLICE_BITS]; + + if (!(data->valid & (1 << slice)) || + time_after(jiffies, data->last_updated[slice])) { + + dev_dbg(&client->dev, "Starting update of slice %u\n", slice); + + data->valid &= ~(1 << slice); + + addr = USER_EEPROM_BASE + (slice << SLICE_BITS); + + /* select the eeprom address */ + if (i2c_smbus_write_byte_data(client, addr >> 8, addr & 0xFF)) { + dev_err(&client->dev, "address set failed\n"); + goto exit_up; + } + + if (i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { + if (i2c_smbus_read_i2c_block_data(client, + MAX6875_CMD_BLK_READ, + SLICE_SIZE, + buf) != SLICE_SIZE) { + goto exit_up; + } + } else { + for (i = 0; i < SLICE_SIZE; i++) { + j = i2c_smbus_read_byte(client); + if (j < 0) { + goto exit_up; + } + buf[i] = j; + } + } + data->last_updated[slice] = jiffies; + data->valid |= (1 << slice); + } +exit_up: + mutex_unlock(&data->update_lock); +} + +static ssize_t max6875_read(struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + struct i2c_client *client = kobj_to_i2c_client(kobj); + struct max6875_data *data = i2c_get_clientdata(client); + int slice, max_slice; + + if (off > USER_EEPROM_SIZE) + return 0; + + if (off + count > USER_EEPROM_SIZE) + count = USER_EEPROM_SIZE - off; + + /* refresh slices which contain requested bytes */ + max_slice = (off + count - 1) >> SLICE_BITS; + for (slice = (off >> SLICE_BITS); slice <= max_slice; slice++) + max6875_update_slice(client, slice); + + memcpy(buf, &data->data[off], count); + + return count; +} + +static struct bin_attribute user_eeprom_attr = { + .attr = { + .name = "eeprom", + .mode = S_IRUGO, + }, + .size = USER_EEPROM_SIZE, + .read = max6875_read, +}; + +/* Return 0 if detection is successful, -ENODEV otherwise */ +static int max6875_detect(struct i2c_client *client, int kind, + struct i2c_board_info *info) +{ + struct i2c_adapter *adapter = client->adapter; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA + | I2C_FUNC_SMBUS_READ_BYTE)) + return -ENODEV; + + /* Only check even addresses */ + if (client->addr & 1) + return -ENODEV; + + strlcpy(info->type, "max6875", I2C_NAME_SIZE); + + return 0; +} + +static int max6875_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct max6875_data *data; + int err; + + if (!(data = kzalloc(sizeof(struct max6875_data), GFP_KERNEL))) + return -ENOMEM; + + /* A fake client is created on the odd address */ + data->fake_client = i2c_new_dummy(client->adapter, client->addr + 1); + if (!data->fake_client) { + err = -ENOMEM; + goto exit_kfree; + } + + /* Init real i2c_client */ + i2c_set_clientdata(client, data); + mutex_init(&data->update_lock); + + err = sysfs_create_bin_file(&client->dev.kobj, &user_eeprom_attr); + if (err) + goto exit_remove_fake; + + return 0; + +exit_remove_fake: + i2c_unregister_device(data->fake_client); +exit_kfree: + kfree(data); + return err; +} + +static int max6875_remove(struct i2c_client *client) +{ + struct max6875_data *data = i2c_get_clientdata(client); + + i2c_unregister_device(data->fake_client); + + sysfs_remove_bin_file(&client->dev.kobj, &user_eeprom_attr); + kfree(data); + + return 0; +} + +static const struct i2c_device_id max6875_id[] = { + { "max6875", 0 }, + { } +}; + +static struct i2c_driver max6875_driver = { + .driver = { + .name = "max6875", + }, + .probe = max6875_probe, + .remove = max6875_remove, + .id_table = max6875_id, + + .detect = max6875_detect, + .address_data = &addr_data, +}; + +static int __init max6875_init(void) +{ + return i2c_add_driver(&max6875_driver); +} + +static void __exit max6875_exit(void) +{ + i2c_del_driver(&max6875_driver); +} + + +MODULE_AUTHOR("Ben Gardner "); +MODULE_DESCRIPTION("MAX6875 driver"); +MODULE_LICENSE("GPL"); + +module_init(max6875_init); +module_exit(max6875_exit); -- cgit v1.2.3