135 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * i2c-versatile.c4 *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 0x0018#define I2C_CONTROLS 0x0019#define I2C_CONTROLC 0x0420#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 int ret;68 69 i2c = devm_kzalloc(&dev->dev, sizeof(struct i2c_versatile), GFP_KERNEL);70 if (!i2c)71 return -ENOMEM;72 73 i2c->base = devm_platform_get_and_ioremap_resource(dev, 0, NULL);74 if (IS_ERR(i2c->base))75 return PTR_ERR(i2c->base);76 77 writel(SCL | SDA, i2c->base + I2C_CONTROLS);78 79 i2c->adap.owner = THIS_MODULE;80 strscpy(i2c->adap.name, "Versatile I2C adapter", sizeof(i2c->adap.name));81 i2c->adap.algo_data = &i2c->algo;82 i2c->adap.dev.parent = &dev->dev;83 i2c->adap.dev.of_node = dev->dev.of_node;84 i2c->algo = i2c_versatile_algo;85 i2c->algo.data = i2c;86 87 i2c->adap.nr = dev->id;88 ret = i2c_bit_add_numbered_bus(&i2c->adap);89 if (ret < 0)90 return ret;91 92 platform_set_drvdata(dev, i2c);93 94 return 0;95}96 97static void i2c_versatile_remove(struct platform_device *dev)98{99 struct i2c_versatile *i2c = platform_get_drvdata(dev);100 101 i2c_del_adapter(&i2c->adap);102}103 104static const struct of_device_id i2c_versatile_match[] = {105 { .compatible = "arm,versatile-i2c", },106 {},107};108MODULE_DEVICE_TABLE(of, i2c_versatile_match);109 110static struct platform_driver i2c_versatile_driver = {111 .probe = i2c_versatile_probe,112 .remove_new = i2c_versatile_remove,113 .driver = {114 .name = "versatile-i2c",115 .of_match_table = i2c_versatile_match,116 },117};118 119static int __init i2c_versatile_init(void)120{121 return platform_driver_register(&i2c_versatile_driver);122}123 124static void __exit i2c_versatile_exit(void)125{126 platform_driver_unregister(&i2c_versatile_driver);127}128 129subsys_initcall(i2c_versatile_init);130module_exit(i2c_versatile_exit);131 132MODULE_DESCRIPTION("ARM Versatile I2C bus driver");133MODULE_LICENSE("GPL");134MODULE_ALIAS("platform:versatile-i2c");135