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687b81d083
I2C of helpers used to live in of_i2c.c but experience (from SPI) shows that it is much cleaner to have this in the core. This also removes a circular dependency between the helpers and the core, and so we can finally register child nodes in the core instead of doing this manually in each driver. So, fix the drivers and documentation, too. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
162 lines
3.6 KiB
C
162 lines
3.6 KiB
C
/*
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* i2c-versatile.c
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*
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* Copyright (C) 2006 ARM Ltd.
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* written by Russell King, Deep Blue Solutions Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/i2c.h>
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#include <linux/i2c-algo-bit.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#define I2C_CONTROL 0x00
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#define I2C_CONTROLS 0x00
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#define I2C_CONTROLC 0x04
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#define SCL (1 << 0)
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#define SDA (1 << 1)
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struct i2c_versatile {
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struct i2c_adapter adap;
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struct i2c_algo_bit_data algo;
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void __iomem *base;
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};
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static void i2c_versatile_setsda(void *data, int state)
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{
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struct i2c_versatile *i2c = data;
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writel(SDA, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC));
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}
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static void i2c_versatile_setscl(void *data, int state)
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{
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struct i2c_versatile *i2c = data;
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writel(SCL, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC));
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}
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static int i2c_versatile_getsda(void *data)
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{
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struct i2c_versatile *i2c = data;
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return !!(readl(i2c->base + I2C_CONTROL) & SDA);
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}
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static int i2c_versatile_getscl(void *data)
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{
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struct i2c_versatile *i2c = data;
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return !!(readl(i2c->base + I2C_CONTROL) & SCL);
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}
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static struct i2c_algo_bit_data i2c_versatile_algo = {
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.setsda = i2c_versatile_setsda,
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.setscl = i2c_versatile_setscl,
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.getsda = i2c_versatile_getsda,
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.getscl = i2c_versatile_getscl,
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.udelay = 30,
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.timeout = HZ,
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};
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static int i2c_versatile_probe(struct platform_device *dev)
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{
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struct i2c_versatile *i2c;
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struct resource *r;
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int ret;
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r = platform_get_resource(dev, IORESOURCE_MEM, 0);
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if (!r) {
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ret = -EINVAL;
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goto err_out;
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}
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if (!request_mem_region(r->start, resource_size(r), "versatile-i2c")) {
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ret = -EBUSY;
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goto err_out;
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}
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i2c = kzalloc(sizeof(struct i2c_versatile), GFP_KERNEL);
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if (!i2c) {
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ret = -ENOMEM;
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goto err_release;
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}
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i2c->base = ioremap(r->start, resource_size(r));
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if (!i2c->base) {
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ret = -ENOMEM;
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goto err_free;
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}
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writel(SCL | SDA, i2c->base + I2C_CONTROLS);
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i2c->adap.owner = THIS_MODULE;
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strlcpy(i2c->adap.name, "Versatile I2C adapter", sizeof(i2c->adap.name));
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i2c->adap.algo_data = &i2c->algo;
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i2c->adap.dev.parent = &dev->dev;
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i2c->adap.dev.of_node = dev->dev.of_node;
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i2c->algo = i2c_versatile_algo;
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i2c->algo.data = i2c;
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i2c->adap.nr = dev->id;
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ret = i2c_bit_add_numbered_bus(&i2c->adap);
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if (ret >= 0) {
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platform_set_drvdata(dev, i2c);
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return 0;
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}
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iounmap(i2c->base);
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err_free:
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kfree(i2c);
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err_release:
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release_mem_region(r->start, resource_size(r));
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err_out:
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return ret;
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}
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static int i2c_versatile_remove(struct platform_device *dev)
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{
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struct i2c_versatile *i2c = platform_get_drvdata(dev);
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i2c_del_adapter(&i2c->adap);
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return 0;
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}
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static const struct of_device_id i2c_versatile_match[] = {
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{ .compatible = "arm,versatile-i2c", },
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{},
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};
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MODULE_DEVICE_TABLE(of, i2c_versatile_match);
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static struct platform_driver i2c_versatile_driver = {
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.probe = i2c_versatile_probe,
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.remove = i2c_versatile_remove,
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.driver = {
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.name = "versatile-i2c",
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.owner = THIS_MODULE,
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.of_match_table = i2c_versatile_match,
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},
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};
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static int __init i2c_versatile_init(void)
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{
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return platform_driver_register(&i2c_versatile_driver);
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}
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static void __exit i2c_versatile_exit(void)
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{
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platform_driver_unregister(&i2c_versatile_driver);
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}
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subsys_initcall(i2c_versatile_init);
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module_exit(i2c_versatile_exit);
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MODULE_DESCRIPTION("ARM Versatile I2C bus driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:versatile-i2c");
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