1 /* 2 * wm831x-i2c.c -- I2C access for Wolfson WM831x PMICs 3 * 4 * Copyright 2009,2010 Wolfson Microelectronics PLC. 5 * 6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License as published by the 10 * Free Software Foundation; either version 2 of the License, or (at your 11 * option) any later version. 12 * 13 */ 14 15 #include <linux/kernel.h> 16 #include <linux/module.h> 17 #include <linux/i2c.h> 18 #include <linux/delay.h> 19 #include <linux/mfd/core.h> 20 #include <linux/slab.h> 21 22 #include <linux/mfd/wm831x/core.h> 23 #include <linux/mfd/wm831x/pdata.h> 24 25 static int wm831x_i2c_read_device(struct wm831x *wm831x, unsigned short reg, 26 int bytes, void *dest) 27 { 28 struct i2c_client *i2c = wm831x->control_data; 29 int ret; 30 u16 r = cpu_to_be16(reg); 31 32 ret = i2c_master_send(i2c, (unsigned char *)&r, 2); 33 if (ret < 0) 34 return ret; 35 if (ret != 2) 36 return -EIO; 37 38 ret = i2c_master_recv(i2c, dest, bytes); 39 if (ret < 0) 40 return ret; 41 if (ret != bytes) 42 return -EIO; 43 return 0; 44 } 45 46 /* Currently we allocate the write buffer on the stack; this is OK for 47 * small writes - if we need to do large writes this will need to be 48 * revised. 49 */ 50 static int wm831x_i2c_write_device(struct wm831x *wm831x, unsigned short reg, 51 int bytes, void *src) 52 { 53 struct i2c_client *i2c = wm831x->control_data; 54 unsigned char msg[bytes + 2]; 55 int ret; 56 57 reg = cpu_to_be16(reg); 58 memcpy(&msg[0], ®, 2); 59 memcpy(&msg[2], src, bytes); 60 61 ret = i2c_master_send(i2c, msg, bytes + 2); 62 if (ret < 0) 63 return ret; 64 if (ret < bytes + 2) 65 return -EIO; 66 67 return 0; 68 } 69 70 static int wm831x_i2c_probe(struct i2c_client *i2c, 71 const struct i2c_device_id *id) 72 { 73 struct wm831x *wm831x; 74 75 wm831x = kzalloc(sizeof(struct wm831x), GFP_KERNEL); 76 if (wm831x == NULL) 77 return -ENOMEM; 78 79 i2c_set_clientdata(i2c, wm831x); 80 wm831x->dev = &i2c->dev; 81 wm831x->control_data = i2c; 82 wm831x->read_dev = wm831x_i2c_read_device; 83 wm831x->write_dev = wm831x_i2c_write_device; 84 85 return wm831x_device_init(wm831x, id->driver_data, i2c->irq); 86 } 87 88 static int wm831x_i2c_remove(struct i2c_client *i2c) 89 { 90 struct wm831x *wm831x = i2c_get_clientdata(i2c); 91 92 wm831x_device_exit(wm831x); 93 94 return 0; 95 } 96 97 static int wm831x_i2c_suspend(struct device *dev) 98 { 99 struct wm831x *wm831x = dev_get_drvdata(dev); 100 101 return wm831x_device_suspend(wm831x); 102 } 103 104 static const struct i2c_device_id wm831x_i2c_id[] = { 105 { "wm8310", WM8310 }, 106 { "wm8311", WM8311 }, 107 { "wm8312", WM8312 }, 108 { "wm8320", WM8320 }, 109 { "wm8321", WM8321 }, 110 { "wm8325", WM8325 }, 111 { "wm8326", WM8326 }, 112 { } 113 }; 114 MODULE_DEVICE_TABLE(i2c, wm831x_i2c_id); 115 116 static const struct dev_pm_ops wm831x_pm_ops = { 117 .suspend = wm831x_i2c_suspend, 118 }; 119 120 static struct i2c_driver wm831x_i2c_driver = { 121 .driver = { 122 .name = "wm831x", 123 .owner = THIS_MODULE, 124 .pm = &wm831x_pm_ops, 125 }, 126 .probe = wm831x_i2c_probe, 127 .remove = wm831x_i2c_remove, 128 .id_table = wm831x_i2c_id, 129 }; 130 131 static int __init wm831x_i2c_init(void) 132 { 133 int ret; 134 135 ret = i2c_add_driver(&wm831x_i2c_driver); 136 if (ret != 0) 137 pr_err("Failed to register wm831x I2C driver: %d\n", ret); 138 139 return ret; 140 } 141 subsys_initcall(wm831x_i2c_init); 142 143 static void __exit wm831x_i2c_exit(void) 144 { 145 i2c_del_driver(&wm831x_i2c_driver); 146 } 147 module_exit(wm831x_i2c_exit); 148