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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/i2c/busses/i2c-simtec.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | drivers/i2c/busses/i2c-simtec.c | 157 |
1 files changed, 157 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..877017447 --- /dev/null +++ b/drivers/i2c/busses/i2c-simtec.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2005 Simtec Electronics + * Ben Dooks <ben@simtec.co.uk> + * + * Simtec Generic I2C Controller +*/ + +#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; + + strscpy(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"); |