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path: root/drivers/i2c/chips/max6875.c
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Diffstat (limited to 'drivers/i2c/chips/max6875.c')
-rw-r--r--drivers/i2c/chips/max6875.c273
1 files changed, 0 insertions, 273 deletions
diff --git a/drivers/i2c/chips/max6875.c b/drivers/i2c/chips/max6875.c
deleted file mode 100644
index fb7ea5637ec..00000000000
--- a/drivers/i2c/chips/max6875.c
+++ /dev/null
@@ -1,273 +0,0 @@
-/*
- max6875.c - driver for MAX6874/MAX6875
-
- Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
-
- Based on i2c/chips/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 <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/i2c.h>
-#include <linux/mutex.h>
-
-/* 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 client;
- struct mutex update_lock;
-
- u32 valid;
- u8 data[USER_EEPROM_SIZE];
- unsigned long last_updated[USER_EEPROM_SLICES];
-};
-
-static int max6875_attach_adapter(struct i2c_adapter *adapter);
-static int max6875_detect(struct i2c_adapter *adapter, int address, int kind);
-static int max6875_detach_client(struct i2c_client *client);
-
-/* This is the driver that will be inserted */
-static struct i2c_driver max6875_driver = {
- .driver = {
- .name = "max6875",
- },
- .attach_adapter = max6875_attach_adapter,
- .detach_client = max6875_detach_client,
-};
-
-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,
-};
-
-static int max6875_attach_adapter(struct i2c_adapter *adapter)
-{
- return i2c_probe(adapter, &addr_data, max6875_detect);
-}
-
-/* This function is called by i2c_probe */
-static int max6875_detect(struct i2c_adapter *adapter, int address, int kind)
-{
- struct i2c_client *real_client;
- struct i2c_client *fake_client;
- struct max6875_data *data;
- int err = 0;
-
- if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA
- | I2C_FUNC_SMBUS_READ_BYTE))
- return 0;
-
- /* Only check even addresses */
- if (address & 1)
- return 0;
-
- if (!(data = kzalloc(sizeof(struct max6875_data), GFP_KERNEL)))
- return -ENOMEM;
-
- /* A fake client is created on the odd address */
- if (!(fake_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {
- err = -ENOMEM;
- goto exit_kfree1;
- }
-
- /* Init real i2c_client */
- real_client = &data->client;
- i2c_set_clientdata(real_client, data);
- real_client->addr = address;
- real_client->adapter = adapter;
- real_client->driver = &max6875_driver;
- real_client->flags = 0;
- strlcpy(real_client->name, "max6875", I2C_NAME_SIZE);
- mutex_init(&data->update_lock);
-
- /* Init fake client data */
- i2c_set_clientdata(fake_client, NULL);
- fake_client->addr = address | 1;
- fake_client->adapter = adapter;
- fake_client->driver = &max6875_driver;
- fake_client->flags = 0;
- strlcpy(fake_client->name, "max6875 subclient", I2C_NAME_SIZE);
-
- /* Prevent 24RF08 corruption (in case of user error) */
- i2c_smbus_write_quick(real_client, 0);
-
- if ((err = i2c_attach_client(real_client)) != 0)
- goto exit_kfree2;
-
- if ((err = i2c_attach_client(fake_client)) != 0)
- goto exit_detach1;
-
- err = sysfs_create_bin_file(&real_client->dev.kobj, &user_eeprom_attr);
- if (err)
- goto exit_detach2;
-
- return 0;
-
-exit_detach2:
- i2c_detach_client(fake_client);
-exit_detach1:
- i2c_detach_client(real_client);
-exit_kfree2:
- kfree(fake_client);
-exit_kfree1:
- kfree(data);
- return err;
-}
-
-/* Will be called for both the real client and the fake client */
-static int max6875_detach_client(struct i2c_client *client)
-{
- int err;
- struct max6875_data *data = i2c_get_clientdata(client);
-
- /* data is NULL for the fake client */
- if (data)
- sysfs_remove_bin_file(&client->dev.kobj, &user_eeprom_attr);
-
- err = i2c_detach_client(client);
- if (err)
- return err;
-
- if (data) /* real client */
- kfree(data);
- else /* fake client */
- kfree(client);
- return 0;
-}
-
-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 <bgardner@wabtec.com>");
-MODULE_DESCRIPTION("MAX6875 driver");
-MODULE_LICENSE("GPL");
-
-module_init(max6875_init);
-module_exit(max6875_exit);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 08:49:26 +0000