LXR linux/drivers/i2c/busses/i2c-versatile.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  i2c-versatile.c
   4 *
   5 *  Copyright (C) 2006 ARM Ltd.
   6 *  written by Russell King, Deep Blue Solutions Ltd.
   7 */
   8#include <linux/kernel.h>
   9#include <linux/module.h>
  10#include <linux/i2c.h>
  11#include <linux/i2c-algo-bit.h>
  12#include <linux/init.h>
  13#include <linux/platform_device.h>
  14#include <linux/slab.h>
  15#include <linux/io.h>
  16
  17#define I2C_CONTROL     0x00
  18#define I2C_CONTROLS    0x00
  19#define I2C_CONTROLC    0x04
  20#define SCL             (1 << 0)
  21#define SDA             (1 << 1)
  22
  23struct i2c_versatile {
  24        struct i2c_adapter       adap;
  25        struct i2c_algo_bit_data algo;
  26        void __iomem             *base;
  27};
  28
  29static void i2c_versatile_setsda(void *data, int state)
  30{
  31        struct i2c_versatile *i2c = data;
  32
  33        writel(SDA, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC));
  34}
  35
  36static void i2c_versatile_setscl(void *data, int state)
  37{
  38        struct i2c_versatile *i2c = data;
  39
  40        writel(SCL, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC));
  41}
  42
  43static int i2c_versatile_getsda(void *data)
  44{
  45        struct i2c_versatile *i2c = data;
  46        return !!(readl(i2c->base + I2C_CONTROL) & SDA);
  47}
  48
  49static int i2c_versatile_getscl(void *data)
  50{
  51        struct i2c_versatile *i2c = data;
  52        return !!(readl(i2c->base + I2C_CONTROL) & SCL);
  53}
  54
  55static const struct i2c_algo_bit_data i2c_versatile_algo = {
  56        .setsda = i2c_versatile_setsda,
  57        .setscl = i2c_versatile_setscl,
  58        .getsda = i2c_versatile_getsda,
  59        .getscl = i2c_versatile_getscl,
  60        .udelay = 30,
  61        .timeout = HZ,
  62};
  63
  64static int i2c_versatile_probe(struct platform_device *dev)
  65{
  66        struct i2c_versatile *i2c;
  67        struct resource *r;
  68        int ret;
  69
  70        i2c = devm_kzalloc(&dev->dev, sizeof(struct i2c_versatile), GFP_KERNEL);
  71        if (!i2c)
  72                return -ENOMEM;
  73
  74        r = platform_get_resource(dev, IORESOURCE_MEM, 0);
  75        i2c->base = devm_ioremap_resource(&dev->dev, r);
  76        if (IS_ERR(i2c->base))
  77                return PTR_ERR(i2c->base);
  78
  79        writel(SCL | SDA, i2c->base + I2C_CONTROLS);
  80
  81        i2c->adap.owner = THIS_MODULE;
  82        strlcpy(i2c->adap.name, "Versatile I2C adapter", sizeof(i2c->adap.name));
  83        i2c->adap.algo_data = &i2c->algo;
  84        i2c->adap.dev.parent = &dev->dev;
  85        i2c->adap.dev.of_node = dev->dev.of_node;
  86        i2c->algo = i2c_versatile_algo;
  87        i2c->algo.data = i2c;
  88
  89        i2c->adap.nr = dev->id;
  90        ret = i2c_bit_add_numbered_bus(&i2c->adap);
  91        if (ret < 0)
  92                return ret;
  93
  94        platform_set_drvdata(dev, i2c);
  95
  96        return 0;
  97}
  98
  99static int i2c_versatile_remove(struct platform_device *dev)
 100{
 101        struct i2c_versatile *i2c = platform_get_drvdata(dev);
 102
 103        i2c_del_adapter(&i2c->adap);
 104        return 0;
 105}
 106
 107static const struct of_device_id i2c_versatile_match[] = {
 108        { .compatible = "arm,versatile-i2c", },
 109        {},
 110};
 111MODULE_DEVICE_TABLE(of, i2c_versatile_match);
 112
 113static struct platform_driver i2c_versatile_driver = {
 114        .probe          = i2c_versatile_probe,
 115        .remove         = i2c_versatile_remove,
 116        .driver         = {
 117                .name   = "versatile-i2c",
 118                .of_match_table = i2c_versatile_match,
 119        },
 120};
 121
 122static int __init i2c_versatile_init(void)
 123{
 124        return platform_driver_register(&i2c_versatile_driver);
 125}
 126
 127static void __exit i2c_versatile_exit(void)
 128{
 129        platform_driver_unregister(&i2c_versatile_driver);
 130}
 131
 132subsys_initcall(i2c_versatile_init);
 133module_exit(i2c_versatile_exit);
 134
 135MODULE_DESCRIPTION("ARM Versatile I2C bus driver");
 136MODULE_LICENSE("GPL");
 137MODULE_ALIAS("platform:versatile-i2c");
 138