/* * 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(struct work_struct *private_); static struct device *akita_ioexp_device; static unsigned char ioexp_output_value = AKITA_IOEXP_IO_OUT; DECLARE_WORK(akita_ioexp, akita_ioexp_work); /* * 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(struct work_struct *private_) { if (akita_ioexp_device) max7310_set_ouputs(akita_ioexp_device, ioexp_output_value); } #ifdef CONFIG_PM static 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 #endif static 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);