/* * i2c-versatile.c * * Copyright (C) 2006 ARM Ltd. * written by Russell King, Deep Blue Solutions Ltd. * * 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/module.h> #include <linux/i2c.h> #include <linux/i2c-algo-bit.h> #include <linux/init.h> #include <linux/platform_device.h> #include <asm/io.h> #define I2C_CONTROL 0x00 #define I2C_CONTROLS 0x00 #define I2C_CONTROLC 0x04 #define SCL (1 << 0) #define SDA (1 << 1) struct i2c_versatile { struct i2c_adapter adap; struct i2c_algo_bit_data algo; void __iomem *base; }; static void i2c_versatile_setsda(void *data, int state) { struct i2c_versatile *i2c = data; writel(SDA, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC)); } static void i2c_versatile_setscl(void *data, int state) { struct i2c_versatile *i2c = data; writel(SCL, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC)); } static int i2c_versatile_getsda(void *data) { struct i2c_versatile *i2c = data; return !!(readl(i2c->base + I2C_CONTROL) & SDA); } static int i2c_versatile_getscl(void *data) { struct i2c_versatile *i2c = data; return !!(readl(i2c->base + I2C_CONTROL) & SCL); } static struct i2c_algo_bit_data i2c_versatile_algo = { .setsda = i2c_versatile_setsda, .setscl = i2c_versatile_setscl, .getsda = i2c_versatile_getsda, .getscl = i2c_versatile_getscl, .udelay = 30, .timeout = HZ, }; static int i2c_versatile_probe(struct platform_device *dev) { struct i2c_versatile *i2c; struct resource *r; int ret; r = platform_get_resource(dev, IORESOURCE_MEM, 0); if (!r) { ret = -EINVAL; goto err_out; } if (!request_mem_region(r->start, r->end - r->start + 1, "versatile-i2c")) { ret = -EBUSY; goto err_out; } i2c = kzalloc(sizeof(struct i2c_versatile), GFP_KERNEL); if (!i2c) { ret = -ENOMEM; goto err_release; } i2c->base = ioremap(r->start, r->end - r->start + 1); if (!i2c->base) { ret = -ENOMEM; goto err_free; } writel(SCL | SDA, i2c->base + I2C_CONTROLS); i2c->adap.owner = THIS_MODULE; strlcpy(i2c->adap.name, "Versatile I2C adapter", sizeof(i2c->adap.name)); i2c->adap.algo_data = &i2c->algo; i2c->adap.dev.parent = &dev->dev; i2c->algo = i2c_versatile_algo; i2c->algo.data = i2c; ret = i2c_bit_add_bus(&i2c->adap); if (ret >= 0) { platform_set_drvdata(dev, i2c); return 0; } iounmap(i2c->base); err_free: kfree(i2c); err_release: release_mem_region(r->start, r->end - r->start + 1); err_out: return ret; } static int i2c_versatile_remove(struct platform_device *dev) { struct i2c_versatile *i2c = platform_get_drvdata(dev); platform_set_drvdata(dev, NULL); i2c_del_adapter(&i2c->adap); return 0; } static struct platform_driver i2c_versatile_driver = { .probe = i2c_versatile_probe, .remove = i2c_versatile_remove, .driver = { .name = "versatile-i2c", .owner = THIS_MODULE, }, }; static int __init i2c_versatile_init(void) { return platform_driver_register(&i2c_versatile_driver); } static void __exit i2c_versatile_exit(void) { platform_driver_unregister(&i2c_versatile_driver); } module_init(i2c_versatile_init); module_exit(i2c_versatile_exit); MODULE_DESCRIPTION("ARM Versatile I2C bus driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:versatile-i2c");