175 lines
3.6 KiB
C
175 lines
3.6 KiB
C
/*
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* at24.c - handle most I2C EEPROMs
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*
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* Copyright (C) 2005-2007 David Brownell
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* Copyright (C) 2008 Wolfram Sang, Pengutronix
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/delay.h>
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#include <linux/mutex.h>
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#include <linux/sysfs.h>
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#include <linux/mod_devicetable.h>
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#include <linux/log2.h>
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#include <linux/bitops.h>
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#include <linux/jiffies.h>
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#include <linux/of.h>
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#include <linux/i2c.h>
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#include <linux/i2c/at24.h>
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#define EEPROM_ATTR(_name) \
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{ \
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.attr = { .name = #_name, .mode = 0444 }, \
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.show = _name##_show, \
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}
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struct i2c_client *this_client;
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static const struct i2c_device_id at24_ids[] = {
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{ "24c16", 0 },
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{ /* END OF LIST */ }
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};
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MODULE_DEVICE_TABLE(i2c, at24_ids);
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static int eeprom_i2c_rxdata(char *rxdata, int length)
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{
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int ret;
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struct i2c_msg msgs[] = {
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{
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.addr = this_client->addr,
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.flags = 0,
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.len = 1,
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.buf = &rxdata[0],
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},
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{
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.addr = this_client->addr,
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.flags = I2C_M_RD,
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.len = length,
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.buf = &rxdata[1],
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},
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};
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ret = i2c_transfer(this_client->adapter, msgs, 2);
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if (ret < 0)
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pr_info("%s i2c read eeprom error: %d\n", __func__, ret);
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return ret;
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}
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static int eeprom_i2c_txdata(char *txdata, int length)
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{
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int ret;
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struct i2c_msg msg[] = {
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{
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.addr = this_client->addr,
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.flags = 0,
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.len = length,
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.buf = txdata,
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},
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};
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ret = i2c_transfer(this_client->adapter, msg, 1);
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if (ret < 0)
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pr_err("%s i2c write eeprom error: %d\n", __func__, ret);
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return 0;
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}
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static ssize_t read_show(struct kobject *kobj, struct kobj_attribute *attr,
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char *buf)
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{
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u8 rxdata[4];
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rxdata[0] = 0x1;
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eeprom_i2c_rxdata(rxdata, 3);
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return sprintf(buf, "Read data : 0x%x, 0x%x, 0x%x, 0x%x\n",
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rxdata[0], rxdata[1], rxdata[2], rxdata[3]);
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}
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static ssize_t write_show(struct kobject *kobj, struct kobj_attribute *attr,
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char *buf)
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{
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static u8 txdata[4] = {0x1, 0xAA, 0xBB, 0xCC};
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txdata[1]++;
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txdata[2]++;
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txdata[3]++;
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eeprom_i2c_txdata(txdata, 4);
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return sprintf(buf, "Write data: 0x%x, 0x%x, 0x%x, 0x%x\n",
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txdata[0], txdata[1], txdata[2], txdata[3]);
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}
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static struct kobj_attribute read = EEPROM_ATTR(read);
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static struct kobj_attribute write = EEPROM_ATTR(write);
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static const struct attribute *test_attrs[] = {
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&read.attr,
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&write.attr,
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NULL,
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};
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static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
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{
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int err;
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this_client = client;
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pr_debug("1..at24_probe\n);
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err = sysfs_create_files(&client->dev.kobj, test_attrs);
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pr_debug("2..at24_probe\n);
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if (err)
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pr_debug("sysfs_create_files failed\n");
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pr_debug("3..at24_probe\n);
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return 0;
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}
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static int at24_remove(struct i2c_client *client)
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{
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sysfs_remove_files(&client->dev.kobj, test_attrs);
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return 0;
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}
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/*-------------------------------------------------------------------------*/
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static struct i2c_driver at24_driver = {
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.driver = {
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.name = "at24",
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.owner = THIS_MODULE,
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},
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.probe = at24_probe,
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.remove = at24_remove,
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.id_table = at24_ids,
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};
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static int __init at24_init(void)
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{
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pr_debug("%d----%d\n", __func__, __LINE__);
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return i2c_add_driver(&at24_driver);
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}
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module_init(at24_init);
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static void __exit at24_exit(void)
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{
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pr_debug("%s()%d\n", __func__, __LINE__);
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i2c_del_driver(&at24_driver);
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}
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module_exit(at24_exit);
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MODULE_DESCRIPTION("24C16 simple test");
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MODULE_AUTHOR("pannan");
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MODULE_LICENSE("GPL");
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