forked from luck/tmp_suning_uos_patched
4c4d887822
This saves us allocating an array on the stack, giving a meaningless performance improvement and ensuring that if drivers ever do large writes we'll not allocate large arrays on the stack. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
156 lines
3.4 KiB
C
156 lines
3.4 KiB
C
/*
|
|
* wm831x-i2c.c -- I2C access for Wolfson WM831x PMICs
|
|
*
|
|
* Copyright 2009,2010 Wolfson Microelectronics PLC.
|
|
*
|
|
* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the
|
|
* Free Software Foundation; either version 2 of the License, or (at your
|
|
* option) any later version.
|
|
*
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/mfd/core.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/mfd/wm831x/core.h>
|
|
#include <linux/mfd/wm831x/pdata.h>
|
|
|
|
static int wm831x_i2c_read_device(struct wm831x *wm831x, unsigned short reg,
|
|
int bytes, void *dest)
|
|
{
|
|
struct i2c_client *i2c = wm831x->control_data;
|
|
int ret;
|
|
u16 r = cpu_to_be16(reg);
|
|
|
|
ret = i2c_master_send(i2c, (unsigned char *)&r, 2);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (ret != 2)
|
|
return -EIO;
|
|
|
|
ret = i2c_master_recv(i2c, dest, bytes);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (ret != bytes)
|
|
return -EIO;
|
|
return 0;
|
|
}
|
|
|
|
/* Currently we allocate the write buffer on the stack; this is OK for
|
|
* small writes - if we need to do large writes this will need to be
|
|
* revised.
|
|
*/
|
|
static int wm831x_i2c_write_device(struct wm831x *wm831x, unsigned short reg,
|
|
int bytes, void *src)
|
|
{
|
|
struct i2c_client *i2c = wm831x->control_data;
|
|
struct i2c_msg xfer[2];
|
|
int ret;
|
|
|
|
reg = cpu_to_be16(reg);
|
|
|
|
xfer[0].addr = i2c->addr;
|
|
xfer[0].flags = 0;
|
|
xfer[0].len = 2;
|
|
xfer[0].buf = (char *)®
|
|
|
|
xfer[1].addr = i2c->addr;
|
|
xfer[1].flags = I2C_M_NOSTART;
|
|
xfer[1].len = bytes;
|
|
xfer[1].buf = (char *)src;
|
|
|
|
ret = i2c_transfer(i2c->adapter, xfer, 2);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (ret != 2)
|
|
return -EIO;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int wm831x_i2c_probe(struct i2c_client *i2c,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct wm831x *wm831x;
|
|
|
|
wm831x = kzalloc(sizeof(struct wm831x), GFP_KERNEL);
|
|
if (wm831x == NULL)
|
|
return -ENOMEM;
|
|
|
|
i2c_set_clientdata(i2c, wm831x);
|
|
wm831x->dev = &i2c->dev;
|
|
wm831x->control_data = i2c;
|
|
wm831x->read_dev = wm831x_i2c_read_device;
|
|
wm831x->write_dev = wm831x_i2c_write_device;
|
|
|
|
return wm831x_device_init(wm831x, id->driver_data, i2c->irq);
|
|
}
|
|
|
|
static int wm831x_i2c_remove(struct i2c_client *i2c)
|
|
{
|
|
struct wm831x *wm831x = i2c_get_clientdata(i2c);
|
|
|
|
wm831x_device_exit(wm831x);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int wm831x_i2c_suspend(struct device *dev)
|
|
{
|
|
struct wm831x *wm831x = dev_get_drvdata(dev);
|
|
|
|
return wm831x_device_suspend(wm831x);
|
|
}
|
|
|
|
static const struct i2c_device_id wm831x_i2c_id[] = {
|
|
{ "wm8310", WM8310 },
|
|
{ "wm8311", WM8311 },
|
|
{ "wm8312", WM8312 },
|
|
{ "wm8320", WM8320 },
|
|
{ "wm8321", WM8321 },
|
|
{ "wm8325", WM8325 },
|
|
{ "wm8326", WM8326 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, wm831x_i2c_id);
|
|
|
|
static const struct dev_pm_ops wm831x_pm_ops = {
|
|
.suspend = wm831x_i2c_suspend,
|
|
};
|
|
|
|
static struct i2c_driver wm831x_i2c_driver = {
|
|
.driver = {
|
|
.name = "wm831x",
|
|
.owner = THIS_MODULE,
|
|
.pm = &wm831x_pm_ops,
|
|
},
|
|
.probe = wm831x_i2c_probe,
|
|
.remove = wm831x_i2c_remove,
|
|
.id_table = wm831x_i2c_id,
|
|
};
|
|
|
|
static int __init wm831x_i2c_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = i2c_add_driver(&wm831x_i2c_driver);
|
|
if (ret != 0)
|
|
pr_err("Failed to register wm831x I2C driver: %d\n", ret);
|
|
|
|
return ret;
|
|
}
|
|
subsys_initcall(wm831x_i2c_init);
|
|
|
|
static void __exit wm831x_i2c_exit(void)
|
|
{
|
|
i2c_del_driver(&wm831x_i2c_driver);
|
|
}
|
|
module_exit(wm831x_i2c_exit);
|