drivers/mfd/wm831x-auxadc.c - arm/linux-arm64-legacy - Git at Google

 /*
  * 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;
 }
	/*
	* 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;
	}