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 struct i2c_msg xfer[2]; 55 int ret; 56 57 reg = cpu_to_be16(reg); 58 59 xfer[0].addr = i2c->addr; 60 xfer[0].flags = 0; 61 xfer[0].len = 2; 62 xfer[0].buf = (char *)® 63 64 xfer[1].addr = i2c->addr; 65 xfer[1].flags = I2C_M_NOSTART; 66 xfer[1].len = bytes; 67 xfer[1].buf = (char *)src; 68 69 ret = i2c_transfer(i2c->adapter, xfer, 2); 70 if (ret < 0) 71 return ret; 72 if (ret != 2) 73 return -EIO; 74 75 return 0; 76 } 77 78 static int wm831x_i2c_probe(struct i2c_client *i2c, 79 const struct i2c_device_id *id) 80 { 81 struct wm831x *wm831x; 82 83 wm831x = kzalloc(sizeof(struct wm831x), GFP_KERNEL); 84 if (wm831x == NULL) 85 return -ENOMEM; 86 87 i2c_set_clientdata(i2c, wm831x); 88 wm831x->dev = &i2c->dev; 89 wm831x->control_data = i2c; 90 wm831x->read_dev = wm831x_i2c_read_device; 91 wm831x->write_dev = wm831x_i2c_write_device; 92 93 return wm831x_device_init(wm831x, id->driver_data, i2c->irq); 94 } 95 96 static int wm831x_i2c_remove(struct i2c_client *i2c) 97 { 98 struct wm831x *wm831x = i2c_get_clientdata(i2c); 99 100 wm831x_device_exit(wm831x); 101 102 return 0; 103 } 104 105 static int wm831x_i2c_suspend(struct device *dev) 106 { 107 struct wm831x *wm831x = dev_get_drvdata(dev); 108 109 return wm831x_device_suspend(wm831x); 110 } 111 112 static const struct i2c_device_id wm831x_i2c_id[] = { 113 { "wm8310", WM8310 }, 114 { "wm8311", WM8311 }, 115 { "wm8312", WM8312 }, 116 { "wm8320", WM8320 }, 117 { "wm8321", WM8321 }, 118 { "wm8325", WM8325 }, 119 { "wm8326", WM8326 }, 120 { } 121 }; 122 MODULE_DEVICE_TABLE(i2c, wm831x_i2c_id); 123 124 static const struct dev_pm_ops wm831x_pm_ops = { 125 .suspend = wm831x_i2c_suspend, 126 }; 127 128 static struct i2c_driver wm831x_i2c_driver = { 129 .driver = { 130 .name = "wm831x", 131 .owner = THIS_MODULE, 132 .pm = &wm831x_pm_ops, 133 }, 134 .probe = wm831x_i2c_probe, 135 .remove = wm831x_i2c_remove, 136 .id_table = wm831x_i2c_id, 137 }; 138 139 static int __init wm831x_i2c_init(void) 140 { 141 int ret; 142 143 ret = i2c_add_driver(&wm831x_i2c_driver); 144 if (ret != 0) 145 pr_err("Failed to register wm831x I2C driver: %d\n", ret); 146 147 return ret; 148 } 149 subsys_initcall(wm831x_i2c_init); 150 151 static void __exit wm831x_i2c_exit(void) 152 { 153 i2c_del_driver(&wm831x_i2c_driver); 154 } 155 module_exit(wm831x_i2c_exit); 156