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/*
* wm831x-auxadc.c -- AUXADC for Wolfson WM831x PMICs
*
* Copyright 2009-2011 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/delay.h>
#include <linux/mfd/core.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/pdata.h>
#include <linux/mfd/wm831x/irq.h>
#include <linux/mfd/wm831x/auxadc.h>
#include <linux/mfd/wm831x/otp.h>
#include <linux/mfd/wm831x/regulator.h>
struct wm831x_auxadc_req {
struct list_head list;
enum wm831x_auxadc input;
int val;
struct completion done;
};
static int wm831x_auxadc_read_irq(struct wm831x *wm831x,
enum wm831x_auxadc input)
{
struct wm831x_auxadc_req *req;
int ret;
bool ena = false;
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (!req)
return -ENOMEM;
init_completion(&req->done);
req->input = input;
req->val = -ETIMEDOUT;
mutex_lock(&wm831x->auxadc_lock);
/* Enqueue the request */
list_add(&req->list, &wm831x->auxadc_pending);
ena = !wm831x->auxadc_active;
if (ena) {
ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
WM831X_AUX_ENA, WM831X_AUX_ENA);
if (ret != 0) {
dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n",
ret);
goto out;
}
}
/* Enable the conversion if not already running */
if (!(wm831x->auxadc_active & (1 << input))) {
ret = wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE,
1 << input, 1 << input);
if (ret != 0) {
dev_err(wm831x->dev,
"Failed to set AUXADC source: %d\n", ret);
goto out;
}
wm831x->auxadc_active |= 1 << input;
}
/* We convert at the fastest rate possible */
if (ena) {
ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
WM831X_AUX_CVT_ENA |
WM831X_AUX_RATE_MASK,
WM831X_AUX_CVT_ENA |
WM831X_AUX_RATE_MASK);
if (ret != 0) {
dev_err(wm831x->dev, "Failed to start AUXADC: %d\n",
ret);
goto out;
}
}
mutex_unlock(&wm831x->auxadc_lock);
/* Wait for an interrupt */
wait_for_completion_timeout(&req->done, msecs_to_jiffies(500));
mutex_lock(&wm831x->auxadc_lock);
list_del(&req->list);
ret = req->val;
out:
mutex_unlock(&wm831x->auxadc_lock);
kfree(req);
return ret;
}
static irqreturn_t wm831x_auxadc_irq(int irq, void *irq_data)
{
struct wm831x *wm831x = irq_data;
struct wm831x_auxadc_req *req;
int ret, input, val;
ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
if (ret < 0) {
dev_err(wm831x->dev,
"Failed to read AUXADC data: %d\n", ret);
return IRQ_NONE;
}
input = ((ret & WM831X_AUX_DATA_SRC_MASK)
>> WM831X_AUX_DATA_SRC_SHIFT) - 1;
if (input == 14)
input = WM831X_AUX_CAL;
val = ret & WM831X_AUX_DATA_MASK;
mutex_lock(&wm831x->auxadc_lock);
/* Disable this conversion, we're about to complete all users */
wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE,
1 << input, 0);
wm831x->auxadc_active &= ~(1 << input);
/* Turn off the entire convertor if idle */
if (!wm831x->auxadc_active)
wm831x_reg_write(wm831x, WM831X_AUXADC_CONTROL, 0);
/* Wake up any threads waiting for this request */
list_for_each_entry(req, &wm831x->auxadc_pending, list) {
if (req->input == input) {
req->val = val;
complete(&req->done);
}
}
mutex_unlock(&wm831x->auxadc_lock);
return IRQ_HANDLED;
}
static int wm831x_auxadc_read_polled(struct wm831x *wm831x,
enum wm831x_auxadc input)
{
int ret, src, timeout;
mutex_lock(&wm831x->auxadc_lock);
ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
WM831X_AUX_ENA, WM831X_AUX_ENA);
if (ret < 0) {
dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n", ret);
goto out;
}
/* We force a single source at present */
src = input;
ret = wm831x_reg_write(wm831x, WM831X_AUXADC_SOURCE,
1 << src);
if (ret < 0) {
dev_err(wm831x->dev, "Failed to set AUXADC source: %d\n", ret);
goto out;
}
ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
WM831X_AUX_CVT_ENA, WM831X_AUX_CVT_ENA);
if (ret < 0) {
dev_err(wm831x->dev, "Failed to start AUXADC: %d\n", ret);
goto disable;
}
/* If we're not using interrupts then poll the
* interrupt status register */
timeout = 5;
while (timeout) {
msleep(1);
ret = wm831x_reg_read(wm831x,
WM831X_INTERRUPT_STATUS_1);
if (ret < 0) {
dev_err(wm831x->dev,
"ISR 1 read failed: %d\n", ret);
goto disable;
}
/* Did it complete? */
if (ret & WM831X_AUXADC_DATA_EINT) {
wm831x_reg_write(wm831x,
WM831X_INTERRUPT_STATUS_1,
WM831X_AUXADC_DATA_EINT);
break;
} else {
dev_err(wm831x->dev,
"AUXADC conversion timeout\n");
ret = -EBUSY;
goto disable;
}
}
ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
if (ret < 0) {
dev_err(wm831x->dev,
"Failed to read AUXADC data: %d\n", ret);
goto disable;
}
src = ((ret & WM831X_AUX_DATA_SRC_MASK)
>> WM831X_AUX_DATA_SRC_SHIFT) - 1;
if (src == 14)
src = WM831X_AUX_CAL;
if (src != input) {
dev_err(wm831x->dev, "Data from source %d not %d\n",
src, input);
ret = -EINVAL;
} else {
ret &= WM831X_AUX_DATA_MASK;
}
disable:
wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL, WM831X_AUX_ENA, 0);
out:
mutex_unlock(&wm831x->auxadc_lock);
return ret;
}
/**
* wm831x_auxadc_read: Read a value from the WM831x AUXADC
*
* @wm831x: Device to read from.
* @input: AUXADC input to read.
*/
int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)
{
return wm831x->auxadc_read(wm831x, input);
}
EXPORT_SYMBOL_GPL(wm831x_auxadc_read);
/**
* wm831x_auxadc_read_uv: Read a voltage from the WM831x AUXADC
*
* @wm831x: Device to read from.
* @input: AUXADC input to read.
*/
int wm831x_auxadc_read_uv(struct wm831x *wm831x, enum wm831x_auxadc input)
{
int ret;
ret = wm831x_auxadc_read(wm831x, input);
if (ret < 0)
return ret;
ret *= 1465;
return ret;
}
EXPORT_SYMBOL_GPL(wm831x_auxadc_read_uv);
void wm831x_auxadc_init(struct wm831x *wm831x)
{
int ret;
mutex_init(&wm831x->auxadc_lock);
INIT_LIST_HEAD(&wm831x->auxadc_pending);
if (wm831x->irq) {
wm831x->auxadc_read = wm831x_auxadc_read_irq;
ret = request_threaded_irq(wm831x_irq(wm831x,
WM831X_IRQ_AUXADC_DATA),
NULL, wm831x_auxadc_irq, 0,
"auxadc", wm831x);
if (ret < 0) {
dev_err(wm831x->dev, "AUXADC IRQ request failed: %d\n",
ret);
wm831x->auxadc_read = NULL;
}
}
if (!wm831x->auxadc_read)
wm831x->auxadc_read = wm831x_auxadc_read_polled;
}
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