diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-versatile.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-versatile.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-versatile.c b/drivers/i2c/busses/i2c-versatile.c new file mode 100644 index 000000000..240637f01 --- /dev/null +++ b/drivers/i2c/busses/i2c-versatile.c @@ -0,0 +1,160 @@ +/* + * 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 <linux/slab.h> +#include <linux/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, resource_size(r), "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, resource_size(r)); + 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->adap.dev.of_node = dev->dev.of_node; + i2c->algo = i2c_versatile_algo; + i2c->algo.data = i2c; + + i2c->adap.nr = dev->id; + ret = i2c_bit_add_numbered_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, resource_size(r)); + err_out: + return ret; +} + +static int i2c_versatile_remove(struct platform_device *dev) +{ + struct i2c_versatile *i2c = platform_get_drvdata(dev); + + i2c_del_adapter(&i2c->adap); + return 0; +} + +static const struct of_device_id i2c_versatile_match[] = { + { .compatible = "arm,versatile-i2c", }, + {}, +}; +MODULE_DEVICE_TABLE(of, i2c_versatile_match); + +static struct platform_driver i2c_versatile_driver = { + .probe = i2c_versatile_probe, + .remove = i2c_versatile_remove, + .driver = { + .name = "versatile-i2c", + .of_match_table = i2c_versatile_match, + }, +}; + +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); +} + +subsys_initcall(i2c_versatile_init); +module_exit(i2c_versatile_exit); + +MODULE_DESCRIPTION("ARM Versatile I2C bus driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:versatile-i2c"); |