1 /* 2 * i2c-versatile.c 3 * 4 * Copyright (C) 2006 ARM Ltd. 5 * written by Russell King, Deep Blue Solutions Ltd. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/i2c.h> 14 #include <linux/i2c-algo-bit.h> 15 #include <linux/init.h> 16 #include <linux/platform_device.h> 17 #include <linux/slab.h> 18 #include <linux/io.h> 19 20 #define I2C_CONTROL 0x00 21 #define I2C_CONTROLS 0x00 22 #define I2C_CONTROLC 0x04 23 #define SCL (1 << 0) 24 #define SDA (1 << 1) 25 26 struct i2c_versatile { 27 struct i2c_adapter adap; 28 struct i2c_algo_bit_data algo; 29 void __iomem *base; 30 }; 31 32 static void i2c_versatile_setsda(void *data, int state) 33 { 34 struct i2c_versatile *i2c = data; 35 36 writel(SDA, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC)); 37 } 38 39 static void i2c_versatile_setscl(void *data, int state) 40 { 41 struct i2c_versatile *i2c = data; 42 43 writel(SCL, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC)); 44 } 45 46 static int i2c_versatile_getsda(void *data) 47 { 48 struct i2c_versatile *i2c = data; 49 return !!(readl(i2c->base + I2C_CONTROL) & SDA); 50 } 51 52 static int i2c_versatile_getscl(void *data) 53 { 54 struct i2c_versatile *i2c = data; 55 return !!(readl(i2c->base + I2C_CONTROL) & SCL); 56 } 57 58 static const struct i2c_algo_bit_data i2c_versatile_algo = { 59 .setsda = i2c_versatile_setsda, 60 .setscl = i2c_versatile_setscl, 61 .getsda = i2c_versatile_getsda, 62 .getscl = i2c_versatile_getscl, 63 .udelay = 30, 64 .timeout = HZ, 65 }; 66 67 static int i2c_versatile_probe(struct platform_device *dev) 68 { 69 struct i2c_versatile *i2c; 70 struct resource *r; 71 int ret; 72 73 i2c = devm_kzalloc(&dev->dev, sizeof(struct i2c_versatile), GFP_KERNEL); 74 if (!i2c) 75 return -ENOMEM; 76 77 r = platform_get_resource(dev, IORESOURCE_MEM, 0); 78 i2c->base = devm_ioremap_resource(&dev->dev, r); 79 if (IS_ERR(i2c->base)) 80 return PTR_ERR(i2c->base); 81 82 writel(SCL | SDA, i2c->base + I2C_CONTROLS); 83 84 i2c->adap.owner = THIS_MODULE; 85 strlcpy(i2c->adap.name, "Versatile I2C adapter", sizeof(i2c->adap.name)); 86 i2c->adap.algo_data = &i2c->algo; 87 i2c->adap.dev.parent = &dev->dev; 88 i2c->adap.dev.of_node = dev->dev.of_node; 89 i2c->algo = i2c_versatile_algo; 90 i2c->algo.data = i2c; 91 92 i2c->adap.nr = dev->id; 93 ret = i2c_bit_add_numbered_bus(&i2c->adap); 94 if (ret < 0) 95 return ret; 96 97 platform_set_drvdata(dev, i2c); 98 99 return 0; 100 } 101 102 static int i2c_versatile_remove(struct platform_device *dev) 103 { 104 struct i2c_versatile *i2c = platform_get_drvdata(dev); 105 106 i2c_del_adapter(&i2c->adap); 107 return 0; 108 } 109 110 static const struct of_device_id i2c_versatile_match[] = { 111 { .compatible = "arm,versatile-i2c", }, 112 {}, 113 }; 114 MODULE_DEVICE_TABLE(of, i2c_versatile_match); 115 116 static struct platform_driver i2c_versatile_driver = { 117 .probe = i2c_versatile_probe, 118 .remove = i2c_versatile_remove, 119 .driver = { 120 .name = "versatile-i2c", 121 .of_match_table = i2c_versatile_match, 122 }, 123 }; 124 125 static int __init i2c_versatile_init(void) 126 { 127 return platform_driver_register(&i2c_versatile_driver); 128 } 129 130 static void __exit i2c_versatile_exit(void) 131 { 132 platform_driver_unregister(&i2c_versatile_driver); 133 } 134 135 subsys_initcall(i2c_versatile_init); 136 module_exit(i2c_versatile_exit); 137 138 MODULE_DESCRIPTION("ARM Versatile I2C bus driver"); 139 MODULE_LICENSE("GPL"); 140 MODULE_ALIAS("platform:versatile-i2c"); 141