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i2c: New ARM Versatile/Realview bus driver
Add support for the I2C bus found on the ARM Versatile and Realview platforms. The I2C bus has a RTC and optionally some EEPROMs attached. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Jean Delvare <khali@linux-fr.org>
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Russell King
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Jean Delvare
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Dec 10, 2006
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,153 @@ | ||
| /* | ||
| * 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; | ||
|
|
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| writel(SDA, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC)); | ||
| } | ||
|
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| static void i2c_versatile_setscl(void *data, int state) | ||
| { | ||
| struct i2c_versatile *i2c = data; | ||
|
|
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| writel(SCL, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC)); | ||
| } | ||
|
|
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| 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; | ||
| } | ||
|
|
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| if (!request_mem_region(r->start, r->end - r->start + 1, "versatile-i2c")) { | ||
| ret = -EBUSY; | ||
| goto err_out; | ||
| } | ||
|
|
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| 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); | ||
|
|
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| 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; | ||
|
|
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| 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; | ||
| } | ||
|
|
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| static int i2c_versatile_remove(struct platform_device *dev) | ||
| { | ||
| struct i2c_versatile *i2c = platform_get_drvdata(dev); | ||
|
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| platform_set_drvdata(dev, NULL); | ||
|
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| i2c_del_adapter(&i2c->adap); | ||
| return 0; | ||
| } | ||
|
|
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| static struct platform_driver i2c_versatile_driver = { | ||
| .probe = i2c_versatile_probe, | ||
| .remove = i2c_versatile_remove, | ||
| .driver = { | ||
| .name = "versatile-i2c", | ||
| .owner = THIS_MODULE, | ||
| }, | ||
| }; | ||
|
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| static int __init i2c_versatile_init(void) | ||
| { | ||
| return platform_driver_register(&i2c_versatile_driver); | ||
| } | ||
|
|
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| static void __exit i2c_versatile_exit(void) | ||
| { | ||
| platform_driver_unregister(&i2c_versatile_driver); | ||
| } | ||
|
|
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| module_init(i2c_versatile_init); | ||
| module_exit(i2c_versatile_exit); | ||
|
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| MODULE_DESCRIPTION("ARM Versatile I2C bus driver"); | ||
| MODULE_LICENSE("GPL"); |