From: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> Something simple to show and explain at ELCE15. Not for inclusion! Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> --- As promised, here is the driver from my talk. Educational only! drivers/i2c/Kconfig | 3 ++ drivers/i2c/Makefile | 1 + drivers/i2c/i2c-slave-8bitseccnt.c | 66 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 70 insertions(+) create mode 100644 drivers/i2c/i2c-slave-8bitseccnt.c diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index 78fbee46362828..c43e00e88b86a3 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -118,6 +118,9 @@ if I2C_SLAVE config I2C_SLAVE_EEPROM tristate "I2C eeprom slave driver" +config I2C_SLAVE_8BIT_SEC_CNT + tristate "I2C 8 bit second counter slave driver" + endif config I2C_DEBUG_CORE diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index 45095b3d16a914..19e8be1020865a 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -9,6 +9,7 @@ obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o obj-$(CONFIG_I2C_MUX) += i2c-mux.o obj-y += algos/ busses/ muxes/ obj-$(CONFIG_I2C_STUB) += i2c-stub.o +obj-$(CONFIG_I2C_SLAVE_8BIT_SEC_CNT) += i2c-slave-8bitseccnt.o obj-$(CONFIG_I2C_SLAVE_EEPROM) += i2c-slave-eeprom.o ccflags-$(CONFIG_I2C_DEBUG_CORE) := -DDEBUG diff --git a/drivers/i2c/i2c-slave-8bitseccnt.c b/drivers/i2c/i2c-slave-8bitseccnt.c new file mode 100644 index 00000000000000..6049989523de6c --- /dev/null +++ b/drivers/i2c/i2c-slave-8bitseccnt.c @@ -0,0 +1,66 @@ +/* + * I2C slave mode 8 bit seconds counter backend :) + * + * Copyright (C) 2015 by Wolfram Sang, Sang Engineering <wsa@xxxxxxxxxxxxxxxxxxxx> + * Copyright (C) 2015 by Renesas Electronics Corporation + * + * 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/init.h> +#include <linux/module.h> +#include <linux/timekeeping.h> + +static int i2c_slave_8bit_seconds_slave_cb(struct i2c_client *client, + enum i2c_slave_event event, u8 *val) +{ + switch (event) { + case I2C_SLAVE_READ_REQUESTED: + case I2C_SLAVE_READ_PROCESSED: + /* Always get the most recent value */ + *val = get_seconds() & 0xff; + break; + + case I2C_SLAVE_WRITE_REQUESTED: + case I2C_SLAVE_WRITE_RECEIVED: + case I2C_SLAVE_STOP: + default: + break; + } + + return 0; +} + +static int i2c_slave_8bit_seconds_probe(struct i2c_client *client, const struct i2c_device_id *id) +{ + return i2c_slave_register(client, i2c_slave_8bit_seconds_slave_cb); +}; + +static int i2c_slave_8bit_seconds_remove(struct i2c_client *client) +{ + i2c_slave_unregister(client); + return 0; +} + +static const struct i2c_device_id i2c_slave_8bit_seconds_id[] = { + { "slave-8bit_seconds", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, i2c_slave_8bit_seconds_id); + +static struct i2c_driver i2c_slave_8bit_seconds_driver = { + .driver = { + .name = "i2c-slave-8bit_seconds", + }, + .probe = i2c_slave_8bit_seconds_probe, + .remove = i2c_slave_8bit_seconds_remove, + .id_table = i2c_slave_8bit_seconds_id, +}; +module_i2c_driver(i2c_slave_8bit_seconds_driver); + +MODULE_AUTHOR("Wolfram Sang <wsa@xxxxxxxxxxxxxxxxxxxx>"); +MODULE_DESCRIPTION("I2C slave mode 8 bit seconds counter backend"); +MODULE_LICENSE("GPL v2"); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html