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157 lines
3.1 KiB
157 lines
3.1 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (C) 2005 Simtec Electronics |
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* Ben Dooks <[email protected]> |
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* |
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* Simtec Generic I2C Controller |
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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/delay.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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#include <linux/i2c.h> |
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#include <linux/i2c-algo-bit.h> |
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struct simtec_i2c_data { |
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struct resource *ioarea; |
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void __iomem *reg; |
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struct i2c_adapter adap; |
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struct i2c_algo_bit_data bit; |
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}; |
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#define CMD_SET_SDA (1<<2) |
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#define CMD_SET_SCL (1<<3) |
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#define STATE_SDA (1<<0) |
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#define STATE_SCL (1<<1) |
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/* i2c bit-bus functions */ |
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static void simtec_i2c_setsda(void *pw, int state) |
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{ |
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struct simtec_i2c_data *pd = pw; |
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writeb(CMD_SET_SDA | (state ? STATE_SDA : 0), pd->reg); |
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} |
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static void simtec_i2c_setscl(void *pw, int state) |
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{ |
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struct simtec_i2c_data *pd = pw; |
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writeb(CMD_SET_SCL | (state ? STATE_SCL : 0), pd->reg); |
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} |
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static int simtec_i2c_getsda(void *pw) |
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{ |
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struct simtec_i2c_data *pd = pw; |
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return readb(pd->reg) & STATE_SDA ? 1 : 0; |
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} |
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static int simtec_i2c_getscl(void *pw) |
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{ |
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struct simtec_i2c_data *pd = pw; |
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return readb(pd->reg) & STATE_SCL ? 1 : 0; |
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} |
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/* device registration */ |
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static int simtec_i2c_probe(struct platform_device *dev) |
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{ |
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struct simtec_i2c_data *pd; |
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struct resource *res; |
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int size; |
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int ret; |
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pd = kzalloc(sizeof(struct simtec_i2c_data), GFP_KERNEL); |
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if (pd == NULL) |
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return -ENOMEM; |
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platform_set_drvdata(dev, pd); |
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res = platform_get_resource(dev, IORESOURCE_MEM, 0); |
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if (res == NULL) { |
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dev_err(&dev->dev, "cannot find IO resource\n"); |
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ret = -ENOENT; |
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goto err; |
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} |
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size = resource_size(res); |
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pd->ioarea = request_mem_region(res->start, size, dev->name); |
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if (pd->ioarea == NULL) { |
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dev_err(&dev->dev, "cannot request IO\n"); |
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ret = -ENXIO; |
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goto err; |
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} |
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pd->reg = ioremap(res->start, size); |
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if (pd->reg == NULL) { |
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dev_err(&dev->dev, "cannot map IO\n"); |
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ret = -ENXIO; |
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goto err_res; |
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} |
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/* setup the private data */ |
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pd->adap.owner = THIS_MODULE; |
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pd->adap.algo_data = &pd->bit; |
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pd->adap.dev.parent = &dev->dev; |
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strlcpy(pd->adap.name, "Simtec I2C", sizeof(pd->adap.name)); |
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pd->bit.data = pd; |
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pd->bit.setsda = simtec_i2c_setsda; |
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pd->bit.setscl = simtec_i2c_setscl; |
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pd->bit.getsda = simtec_i2c_getsda; |
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pd->bit.getscl = simtec_i2c_getscl; |
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pd->bit.timeout = HZ; |
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pd->bit.udelay = 20; |
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ret = i2c_bit_add_bus(&pd->adap); |
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if (ret) |
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goto err_all; |
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return 0; |
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err_all: |
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iounmap(pd->reg); |
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err_res: |
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release_mem_region(pd->ioarea->start, size); |
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err: |
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kfree(pd); |
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return ret; |
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} |
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static int simtec_i2c_remove(struct platform_device *dev) |
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{ |
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struct simtec_i2c_data *pd = platform_get_drvdata(dev); |
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i2c_del_adapter(&pd->adap); |
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iounmap(pd->reg); |
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release_mem_region(pd->ioarea->start, resource_size(pd->ioarea)); |
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kfree(pd); |
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return 0; |
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} |
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/* device driver */ |
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static struct platform_driver simtec_i2c_driver = { |
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.driver = { |
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.name = "simtec-i2c", |
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}, |
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.probe = simtec_i2c_probe, |
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.remove = simtec_i2c_remove, |
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}; |
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module_platform_driver(simtec_i2c_driver); |
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MODULE_DESCRIPTION("Simtec Generic I2C Bus driver"); |
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MODULE_AUTHOR("Ben Dooks <[email protected]>"); |
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MODULE_LICENSE("GPL"); |
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MODULE_ALIAS("platform:simtec-i2c");
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