diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-simtec.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-simtec.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-simtec.c b/drivers/i2c/busses/i2c-simtec.c new file mode 100644 index 000000000..adca51a99 --- /dev/null +++ b/drivers/i2c/busses/i2c-simtec.c @@ -0,0 +1,165 @@ +/* + * Copyright (C) 2005 Simtec Electronics + * Ben Dooks <ben@simtec.co.uk> + * + * Simtec Generic I2C Controller + * + * 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; either version 2 of the License + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. +*/ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/io.h> + +#include <linux/i2c.h> +#include <linux/i2c-algo-bit.h> + +struct simtec_i2c_data { + struct resource *ioarea; + void __iomem *reg; + struct i2c_adapter adap; + struct i2c_algo_bit_data bit; +}; + +#define CMD_SET_SDA (1<<2) +#define CMD_SET_SCL (1<<3) + +#define STATE_SDA (1<<0) +#define STATE_SCL (1<<1) + +/* i2c bit-bus functions */ + +static void simtec_i2c_setsda(void *pw, int state) +{ + struct simtec_i2c_data *pd = pw; + writeb(CMD_SET_SDA | (state ? STATE_SDA : 0), pd->reg); +} + +static void simtec_i2c_setscl(void *pw, int state) +{ + struct simtec_i2c_data *pd = pw; + writeb(CMD_SET_SCL | (state ? STATE_SCL : 0), pd->reg); +} + +static int simtec_i2c_getsda(void *pw) +{ + struct simtec_i2c_data *pd = pw; + return readb(pd->reg) & STATE_SDA ? 1 : 0; +} + +static int simtec_i2c_getscl(void *pw) +{ + struct simtec_i2c_data *pd = pw; + return readb(pd->reg) & STATE_SCL ? 1 : 0; +} + +/* device registration */ + +static int simtec_i2c_probe(struct platform_device *dev) +{ + struct simtec_i2c_data *pd; + struct resource *res; + int size; + int ret; + + pd = kzalloc(sizeof(struct simtec_i2c_data), GFP_KERNEL); + if (pd == NULL) + return -ENOMEM; + + platform_set_drvdata(dev, pd); + + res = platform_get_resource(dev, IORESOURCE_MEM, 0); + if (res == NULL) { + dev_err(&dev->dev, "cannot find IO resource\n"); + ret = -ENOENT; + goto err; + } + + size = resource_size(res); + + pd->ioarea = request_mem_region(res->start, size, dev->name); + if (pd->ioarea == NULL) { + dev_err(&dev->dev, "cannot request IO\n"); + ret = -ENXIO; + goto err; + } + + pd->reg = ioremap(res->start, size); + if (pd->reg == NULL) { + dev_err(&dev->dev, "cannot map IO\n"); + ret = -ENXIO; + goto err_res; + } + + /* setup the private data */ + + pd->adap.owner = THIS_MODULE; + pd->adap.algo_data = &pd->bit; + pd->adap.dev.parent = &dev->dev; + + strlcpy(pd->adap.name, "Simtec I2C", sizeof(pd->adap.name)); + + pd->bit.data = pd; + pd->bit.setsda = simtec_i2c_setsda; + pd->bit.setscl = simtec_i2c_setscl; + pd->bit.getsda = simtec_i2c_getsda; + pd->bit.getscl = simtec_i2c_getscl; + pd->bit.timeout = HZ; + pd->bit.udelay = 20; + + ret = i2c_bit_add_bus(&pd->adap); + if (ret) + goto err_all; + + return 0; + + err_all: + iounmap(pd->reg); + + err_res: + release_mem_region(pd->ioarea->start, size); + + err: + kfree(pd); + return ret; +} + +static int simtec_i2c_remove(struct platform_device *dev) +{ + struct simtec_i2c_data *pd = platform_get_drvdata(dev); + + i2c_del_adapter(&pd->adap); + + iounmap(pd->reg); + release_mem_region(pd->ioarea->start, resource_size(pd->ioarea)); + kfree(pd); + + return 0; +} + +/* device driver */ + +static struct platform_driver simtec_i2c_driver = { + .driver = { + .name = "simtec-i2c", + }, + .probe = simtec_i2c_probe, + .remove = simtec_i2c_remove, +}; + +module_platform_driver(simtec_i2c_driver); + +MODULE_DESCRIPTION("Simtec Generic I2C Bus driver"); +MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:simtec-i2c"); |