1 /* 2 * AD7879-1/AD7889-1 touchscreen (I2C bus) 3 * 4 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc. 5 * 6 * Licensed under the GPL-2 or later. 7 */ 8 9 #include <linux/input.h> /* BUS_I2C */ 10 #include <linux/i2c.h> 11 #include <linux/module.h> 12 #include <linux/types.h> 13 14 #include "ad7879.h" 15 16 #define AD7879_DEVID 0x79 /* AD7879-1/AD7889-1 */ 17 18 #ifdef CONFIG_PM 19 static int ad7879_i2c_suspend(struct i2c_client *client, pm_message_t message) 20 { 21 struct ad7879 *ts = i2c_get_clientdata(client); 22 23 ad7879_disable(ts); 24 25 return 0; 26 } 27 28 static int ad7879_i2c_resume(struct i2c_client *client) 29 { 30 struct ad7879 *ts = i2c_get_clientdata(client); 31 32 ad7879_enable(ts); 33 34 return 0; 35 } 36 #else 37 # define ad7879_i2c_suspend NULL 38 # define ad7879_i2c_resume NULL 39 #endif 40 41 /* All registers are word-sized. 42 * AD7879 uses a high-byte first convention. 43 */ 44 static int ad7879_i2c_read(struct device *dev, u8 reg) 45 { 46 struct i2c_client *client = to_i2c_client(dev); 47 48 return swab16(i2c_smbus_read_word_data(client, reg)); 49 } 50 51 static int ad7879_i2c_multi_read(struct device *dev, 52 u8 first_reg, u8 count, u16 *buf) 53 { 54 u8 idx; 55 56 for (idx = 0; idx < count; ++idx) 57 buf[idx] = ad7879_i2c_read(dev, first_reg + idx); 58 59 return 0; 60 } 61 62 static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val) 63 { 64 struct i2c_client *client = to_i2c_client(dev); 65 66 return i2c_smbus_write_word_data(client, reg, swab16(val)); 67 } 68 69 static const struct ad7879_bus_ops ad7879_i2c_bus_ops = { 70 .bustype = BUS_I2C, 71 .read = ad7879_i2c_read, 72 .multi_read = ad7879_i2c_multi_read, 73 .write = ad7879_i2c_write, 74 }; 75 76 static int __devinit ad7879_i2c_probe(struct i2c_client *client, 77 const struct i2c_device_id *id) 78 { 79 struct ad7879 *ts; 80 81 if (!i2c_check_functionality(client->adapter, 82 I2C_FUNC_SMBUS_WORD_DATA)) { 83 dev_err(&client->dev, "SMBUS Word Data not Supported\n"); 84 return -EIO; 85 } 86 87 ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq, 88 &ad7879_i2c_bus_ops); 89 if (IS_ERR(ts)) 90 return PTR_ERR(ts); 91 92 i2c_set_clientdata(client, ts); 93 94 return 0; 95 } 96 97 static int __devexit ad7879_i2c_remove(struct i2c_client *client) 98 { 99 struct ad7879 *ts = i2c_get_clientdata(client); 100 101 ad7879_remove(ts); 102 103 return 0; 104 } 105 106 static const struct i2c_device_id ad7879_id[] = { 107 { "ad7879", 0 }, 108 { "ad7889", 0 }, 109 { } 110 }; 111 MODULE_DEVICE_TABLE(i2c, ad7879_id); 112 113 static struct i2c_driver ad7879_i2c_driver = { 114 .driver = { 115 .name = "ad7879", 116 .owner = THIS_MODULE, 117 }, 118 .probe = ad7879_i2c_probe, 119 .remove = __devexit_p(ad7879_i2c_remove), 120 .suspend = ad7879_i2c_suspend, 121 .resume = ad7879_i2c_resume, 122 .id_table = ad7879_id, 123 }; 124 125 static int __init ad7879_i2c_init(void) 126 { 127 return i2c_add_driver(&ad7879_i2c_driver); 128 } 129 module_init(ad7879_i2c_init); 130 131 static void __exit ad7879_i2c_exit(void) 132 { 133 i2c_del_driver(&ad7879_i2c_driver); 134 } 135 module_exit(ad7879_i2c_exit); 136 137 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 138 MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver"); 139 MODULE_LICENSE("GPL"); 140 MODULE_ALIAS("i2c:ad7879"); 141