linux/drivers/mfd/wm831x-auxadc.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

296 lines
6.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* wm831x-auxadc.c -- AUXADC for Wolfson WM831x PMICs
*
* Copyright 2009-2011 Wolfson Microelectronics PLC.
*
* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
*/
#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,
IRQF_ONESHOT,
"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;
}