From: Wolfram Sang <[email protected]> Not for upstream yet.
Signed-off-by: Wolfram Sang <[email protected]> --- drivers/i2c/i2c-slave-eeprom.c | 140 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 140 insertions(+) create mode 100644 drivers/i2c/i2c-slave-eeprom.c diff --git a/drivers/i2c/i2c-slave-eeprom.c b/drivers/i2c/i2c-slave-eeprom.c new file mode 100644 index 000000000000..f12edd316ad5 --- /dev/null +++ b/drivers/i2c/i2c-slave-eeprom.c @@ -0,0 +1,140 @@ +/* + * I2C Slave mode EEPROM simulator + * + * Copyright (C) 2014 by Wolfram Sang + * + * 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/i2c.h> +#include <linux/i2c-slave.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/slab.h> +#include <linux/sysfs.h> + +#define EEPROM_SIZE 256 + +struct i2c_slave_eeprom_data { + struct mutex lock; + struct bin_attribute bin; + u8 buffer[EEPROM_SIZE]; + u8 eeprom_ptr; + bool first_write_done; +}; + +static int at24s_slave_cb(struct i2c_client *client, enum i2c_slave_event event, u8 *val) +{ + struct i2c_slave_eeprom_data *at24s = i2c_get_clientdata(client); + + switch (event) { + case I2C_SLAVE_REQ_WRITE: + if (!at24s->first_write_done) + at24s->eeprom_ptr = *val; + else + at24s->buffer[at24s->eeprom_ptr++] = *val; + + at24s->first_write_done = true; + break; + + case I2C_SLAVE_REQ_READ: + *val = at24s->buffer[at24s->eeprom_ptr++]; + break; + + case I2C_SLAVE_STOP: + at24s->first_write_done = false; + break; + } + + return 0; +} + +static ssize_t at24s_bin_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *attr, char *buf, loff_t off, size_t count) +{ + struct i2c_slave_eeprom_data *at24s; + + at24s = dev_get_drvdata(container_of(kobj, struct device, kobj)); + + memcpy(buf, &at24s->buffer[off], count); + + return count; +} + +static ssize_t at24s_bin_write(struct file *filp, struct kobject *kobj, + struct bin_attribute *attr, char *buf, loff_t off, size_t count) +{ + struct i2c_slave_eeprom_data *at24s; + + if (unlikely(off >= attr->size)) + return -EFBIG; + + at24s = dev_get_drvdata(container_of(kobj, struct device, kobj)); + + memcpy(&at24s->buffer[off], buf, count); + + return count; +} + +static int i2c_slave_eeprom_probe(struct i2c_client *client, const struct i2c_device_id *id) +{ + struct i2c_slave_eeprom_data *at24s; + int ret; + + at24s = devm_kzalloc(&client->dev, sizeof(struct i2c_slave_eeprom_data), GFP_KERNEL); + if (!at24s) + return -ENOMEM; + + i2c_set_clientdata(client, at24s); + + ret = i2c_slave_register(client, at24s_slave_cb); + if (ret) + return ret; + + sysfs_bin_attr_init(&at24s->bin); + at24s->bin.attr.name = "slave-eeprom"; + at24s->bin.attr.mode = S_IRUSR | S_IWUSR; + at24s->bin.read = at24s_bin_read; + at24s->bin.write = at24s_bin_write; + at24s->bin.size = EEPROM_SIZE; + + ret = sysfs_create_bin_file(&client->dev.kobj, &at24s->bin); + if (ret) + return ret; + + return 0; +}; + +static int i2c_slave_eeprom_remove(struct i2c_client *client) +{ + struct i2c_slave_eeprom_data *at24s; + + at24s = i2c_get_clientdata(client); + sysfs_remove_bin_file(&client->dev.kobj, &at24s->bin); + + return i2c_slave_unregister(client); +} + +static const struct i2c_device_id i2c_slave_eeprom_id[] = { + { "i2c-slave-eeprom", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, i2c_slave_eeprom_id); + +static struct i2c_driver i2c_slave_eeprom_driver = { + .driver = { + .name = "i2c-slave-eeprom", + .owner = THIS_MODULE, + }, + .probe = i2c_slave_eeprom_probe, + .remove = i2c_slave_eeprom_remove, + .id_table = i2c_slave_eeprom_id, +}; +module_i2c_driver(i2c_slave_eeprom_driver); + +MODULE_AUTHOR("Wolfram Sang <[email protected]>"); +MODULE_DESCRIPTION("I2C Slave mode EEPROM simulator"); +MODULE_LICENSE("GPL v2"); -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
