/* * Support for the Extra GPIOs on the Sharp SL-C1000 (Akita) * (uses a Maxim MAX7310 8 Port IO Expander) * * Copyright 2005 Openedhand Ltd. * * Author: Richard Purdie <richard@openedhand.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * */#include <linux/kernel.h>#include <linux/init.h>#include <linux/platform_device.h>#include <linux/module.h>#include <linux/i2c.h>#include <linux/slab.h>#include <linux/workqueue.h>#include <asm/arch/akita.h>/* MAX7310 Regiser Map */#define MAX7310_INPUT    0x00#define MAX7310_OUTPUT   0x01#define MAX7310_POLINV   0x02#define MAX7310_IODIR    0x03 /* 1 = Input, 0 = Output */#define MAX7310_TIMEOUT  0x04/* Addresses to scan */static unsigned short normal_i2c[] = { 0x18, I2C_CLIENT_END };/* I2C Magic */I2C_CLIENT_INSMOD;static int max7310_write(struct i2c_client *client, int address, int data);static struct i2c_client max7310_template;static void akita_ioexp_work(void *private_);static struct device *akita_ioexp_device;static unsigned char ioexp_output_value = AKITA_IOEXP_IO_OUT;DECLARE_WORK(akita_ioexp, akita_ioexp_work, NULL);/* * MAX7310 Access */static int max7310_config(struct device *dev, int iomode, int polarity){	int ret;	struct i2c_client *client = to_i2c_client(dev);	ret = max7310_write(client, MAX7310_POLINV, polarity);	if (ret < 0)		return ret;	ret = max7310_write(client, MAX7310_IODIR, iomode);	return ret;}static int max7310_set_ouputs(struct device *dev, int outputs){	struct i2c_client *client = to_i2c_client(dev);	return max7310_write(client, MAX7310_OUTPUT, outputs);}/* * I2C Functions */static int max7310_write(struct i2c_client *client, int address, int value){	u8 data[2];	data[0] = address & 0xff;	data[1] = value & 0xff;	if (i2c_master_send(client, data, 2) == 2)		return 0;	return -1;}static int max7310_detect(struct i2c_adapter *adapter, int address, int kind){	struct i2c_client *new_client;	int err;	if (!(new_client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL)))		return -ENOMEM;	max7310_template.adapter = adapter;	max7310_template.addr = address;	memcpy(new_client, &max7310_template, sizeof(struct i2c_client));	if ((err = i2c_attach_client(new_client))) {		kfree(new_client);		return err;	}	max7310_config(&new_client->dev, AKITA_IOEXP_IO_DIR, 0);	akita_ioexp_device = &new_client->dev;	schedule_work(&akita_ioexp);	return 0;}static int max7310_attach_adapter(struct i2c_adapter *adapter){	return i2c_probe(adapter, &addr_data, max7310_detect);}static int max7310_detach_client(struct i2c_client *client){	int err;	akita_ioexp_device = NULL;	if ((err = i2c_detach_client(client)))		return err;	kfree(client);	return 0;}static struct i2c_driver max7310_i2c_driver = {	.driver = {		.name	= "akita-max7310",	},	.id		= I2C_DRIVERID_AKITAIOEXP,	.attach_adapter	= max7310_attach_adapter,	.detach_client	= max7310_detach_client,};static struct i2c_client max7310_template = {	name:   "akita-max7310",	driver: &max7310_i2c_driver,};void akita_set_ioexp(struct device *dev, unsigned char bit){	ioexp_output_value |= bit;	if (akita_ioexp_device)		schedule_work(&akita_ioexp);	return;}void akita_reset_ioexp(struct device *dev, unsigned char bit){	ioexp_output_value &= ~bit;	if (akita_ioexp_device)		schedule_work(&akita_ioexp);	return;}EXPORT_SYMBOL(akita_set_ioexp);EXPORT_SYMBOL(akita_reset_ioexp);static void akita_ioexp_work(void *private_){	if (akita_ioexp_device)		max7310_set_ouputs(akita_ioexp_device, ioexp_output_value);}#ifdef CONFIG_PMstatic int akita_ioexp_suspend(struct platform_device *pdev, pm_message_t state){	flush_scheduled_work();	return 0;}static int akita_ioexp_resume(struct platform_device *pdev){	schedule_work(&akita_ioexp);	return 0;}#else#define akita_ioexp_suspend NULL#define akita_ioexp_resume NULL#endifstatic int __init akita_ioexp_probe(struct platform_device *pdev){	return i2c_add_driver(&max7310_i2c_driver);}static int akita_ioexp_remove(struct platform_device *pdev){	i2c_del_driver(&max7310_i2c_driver);	return 0;}static struct platform_driver akita_ioexp_driver = {	.probe		= akita_ioexp_probe,	.remove		= akita_ioexp_remove,	.suspend	= akita_ioexp_suspend,	.resume		= akita_ioexp_resume,	.driver		= {		.name	= "akita-ioexp",	},};static int __init akita_ioexp_init(void){	return platform_driver_register(&akita_ioexp_driver);}static void __exit akita_ioexp_exit(void){	platform_driver_unregister(&akita_ioexp_driver);}MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");MODULE_DESCRIPTION("Akita IO-Expander driver");MODULE_LICENSE("GPL");fs_initcall(akita_ioexp_init);module_exit(akita_ioexp_exit);