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Commit 6321992c authored by Daniel Willerud's avatar Daniel Willerud Committed by Samuel Ortiz
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mfd: Reentrance and revamp ab8500 gpadc fetching interface 



This revamps the interface so that AB8500 GPADCs are fetched by
name. Probed GPADCs are added to a list and this list is searched
for a matching GPADC. This makes it possible to have multiple
AB8500 GPADC instances instead of it being a singleton, and
rids the need to keep a GPADC pointer around in the core AB8500
MFD struct.

Currently the match is made to the device name which is by default
numbered from the device instance such as "ab8500-gpadc.0" but
by using the .init_name field of the device a more intiutive
naming for the GPADC blocks can be achieved if desired.

Signed-off-by: default avatarDaniel Willerud <daniel.willerud@stericsson.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent cf169439

drivers/mfd/ab8500-gpadc.c

+70 −45
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
 *

 * License Terms: GNU General Public License v2

 * Author: Arun R Murthy <arun.murthy@stericsson.com>

 * Author: Daniel Willerud <daniel.willerud@stericsson.com>

 */

#include <linux/init.h>

#include <linux/module.h>
@@ -15,6 +16,7 @@ 
#include <linux/regulator/consumer.h>

#include <linux/err.h>

#include <linux/slab.h>

#include <linux/list.h>

#include <linux/mfd/ab8500.h>

#include <linux/mfd/abx500.h>

#include <linux/mfd/ab8500/ab8500-gpadc.h>
@@ -48,21 +50,41 @@ 
/**

 * struct ab8500_gpadc - ab8500 GPADC device information

 * @dev:			pointer to the struct device

 * @parent:			pointer to the parent device structure ab8500

 * @node:			a list of AB8500 GPADCs, hence prepared for

				reentrance

 * @ab8500_gpadc_complete:	pointer to the struct completion, to indicate

 *				the completion of gpadc conversion

 * @ab8500_gpadc_lock:		structure of type mutex

 * @regu:			pointer to the struct regulator

 * @irq:			interrupt number that is used by gpadc

 */

static struct ab8500_gpadc {

struct ab8500_gpadc {

	struct device *dev;

	struct ab8500 *parent;

	struct list_head node;

	struct completion ab8500_gpadc_complete;

	struct mutex ab8500_gpadc_lock;

	struct regulator *regu;

	int irq;

} *di;

};



static LIST_HEAD(ab8500_gpadc_list);



/**

 * ab8500_gpadc_get() - returns a reference to the primary AB8500 GPADC

 * (i.e. the first GPADC in the instance list)

 */

struct ab8500_gpadc *ab8500_gpadc_get(char *name)

{

	struct ab8500_gpadc *gpadc;



	list_for_each_entry(gpadc, &ab8500_gpadc_list, node) {

		if (!strcmp(name, dev_name(gpadc->dev)))

		    return gpadc;

	}



	return ERR_PTR(-ENOENT);

}

EXPORT_SYMBOL(ab8500_gpadc_get);



/**

 * ab8500_gpadc_convert() - gpadc conversion
@@ -72,24 +94,24 @@ static struct ab8500_gpadc { 
 * data. Thereafter calibration has to be made to obtain the

 * data in the required quantity measurement.

 */

int ab8500_gpadc_convert(u8 input)

int ab8500_gpadc_convert(struct ab8500_gpadc *gpadc, u8 input)

{

	int ret;

	u16 data = 0;

	int looplimit = 0;

	u8 val, low_data, high_data;



	if (!di)

	if (!gpadc)

		return -ENODEV;



	mutex_lock(&di->ab8500_gpadc_lock);

	mutex_lock(&gpadc->ab8500_gpadc_lock);

	/* Enable VTVout LDO this is required for GPADC */

	regulator_enable(di->regu);

	regulator_enable(gpadc->regu);



	/* Check if ADC is not busy, lock and proceed */

	do {

		ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,

			AB8500_GPADC_STAT_REG, &val);

		ret = abx500_get_register_interruptible(gpadc->dev,

			AB8500_GPADC, AB8500_GPADC_STAT_REG, &val);

		if (ret < 0)

			goto out;

		if (!(val & GPADC_BUSY))
@@ -97,75 +119,76 @@ int ab8500_gpadc_convert(u8 input) 
		msleep(10);

	} while (++looplimit < 10);

	if (looplimit >= 10 && (val & GPADC_BUSY)) {

		dev_err(di->dev, "gpadc_conversion: GPADC busy");

		dev_err(gpadc->dev, "gpadc_conversion: GPADC busy");

		ret = -EINVAL;

		goto out;

	}



	/* Enable GPADC */

	ret = abx500_mask_and_set_register_interruptible(di->dev, AB8500_GPADC,

		AB8500_GPADC_CTRL1_REG, EN_GPADC, EN_GPADC);

	ret = abx500_mask_and_set_register_interruptible(gpadc->dev,

		AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_GPADC, EN_GPADC);

	if (ret < 0) {

		dev_err(di->dev, "gpadc_conversion: enable gpadc failed\n");

		dev_err(gpadc->dev, "gpadc_conversion: enable gpadc failed\n");

		goto out;

	}

	/* Select the input source and set average samples to 16 */

	ret = abx500_set_register_interruptible(di->dev, AB8500_GPADC,

	ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,

		AB8500_GPADC_CTRL2_REG, (input | SW_AVG_16));

	if (ret < 0) {

		dev_err(di->dev,

		dev_err(gpadc->dev,

			"gpadc_conversion: set avg samples failed\n");

		goto out;

	}

	/* Enable ADC, Buffering and select rising edge, start Conversion */

	ret = abx500_mask_and_set_register_interruptible(di->dev, AB8500_GPADC,

		AB8500_GPADC_CTRL1_REG, EN_BUF, EN_BUF);

	ret = abx500_mask_and_set_register_interruptible(gpadc->dev,

		AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_BUF, EN_BUF);

	if (ret < 0) {

		dev_err(di->dev,

		dev_err(gpadc->dev,

			"gpadc_conversion: select falling edge failed\n");

		goto out;

	}

	ret = abx500_mask_and_set_register_interruptible(di->dev, AB8500_GPADC,

		AB8500_GPADC_CTRL1_REG, ADC_SW_CONV, ADC_SW_CONV);

	ret = abx500_mask_and_set_register_interruptible(gpadc->dev,

		AB8500_GPADC, AB8500_GPADC_CTRL1_REG, ADC_SW_CONV, ADC_SW_CONV);

	if (ret < 0) {

		dev_err(di->dev,

		dev_err(gpadc->dev,

			"gpadc_conversion: start s/w conversion failed\n");

		goto out;

	}

	/* wait for completion of conversion */

	if (!wait_for_completion_timeout(&di->ab8500_gpadc_complete, 2*HZ)) {

		dev_err(di->dev,

	if (!wait_for_completion_timeout(&gpadc->ab8500_gpadc_complete, 2*HZ)) {

		dev_err(gpadc->dev,

			"timeout: didnt recieve GPADC conversion interrupt\n");

		ret = -EINVAL;

		goto out;

	}



	/* Read the converted RAW data */

	ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,

	ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,

		AB8500_GPADC_MANDATAL_REG, &low_data);

	if (ret < 0) {

		dev_err(di->dev, "gpadc_conversion: read low data failed\n");

		dev_err(gpadc->dev, "gpadc_conversion: read low data failed\n");

		goto out;

	}



	ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,

	ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,

		AB8500_GPADC_MANDATAH_REG, &high_data);

	if (ret < 0) {

		dev_err(di->dev, "gpadc_conversion: read high data failed\n");

		dev_err(gpadc->dev,

			"gpadc_conversion: read high data failed\n");

		goto out;

	}



	data = (high_data << 8) | low_data;

	/* Disable GPADC */

	ret = abx500_set_register_interruptible(di->dev, AB8500_GPADC,

	ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,

		AB8500_GPADC_CTRL1_REG, DIS_GPADC);

	if (ret < 0) {

		dev_err(di->dev, "gpadc_conversion: disable gpadc failed\n");

		dev_err(gpadc->dev, "gpadc_conversion: disable gpadc failed\n");

		goto out;

	}

	/* Disable VTVout LDO this is required for GPADC */

	regulator_disable(di->regu);

	mutex_unlock(&di->ab8500_gpadc_lock);

	regulator_disable(gpadc->regu);

	mutex_unlock(&gpadc->ab8500_gpadc_lock);

	return data;



out:
@@ -175,12 +198,12 @@ out: 
	 * GPADC status register to go low. In V1.1 there wait_for_completion

	 * seems to timeout when waiting for an interrupt.. Not seen in V2.0

	 */

	(void) abx500_set_register_interruptible(di->dev, AB8500_GPADC,

	(void) abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,

		AB8500_GPADC_CTRL1_REG, DIS_GPADC);

	regulator_disable(di->regu);

	mutex_unlock(&di->ab8500_gpadc_lock);

	dev_err(di->dev, "gpadc_conversion: Failed to AD convert channel %d\n",

		input);

	regulator_disable(gpadc->regu);

	mutex_unlock(&gpadc->ab8500_gpadc_lock);

	dev_err(gpadc->dev,

		"gpadc_conversion: Failed to AD convert channel %d\n", input);

	return ret;

}

EXPORT_SYMBOL(ab8500_gpadc_convert);
@@ -195,9 +218,9 @@ EXPORT_SYMBOL(ab8500_gpadc_convert); 
 * can be read from the registers.

 * Returns IRQ status(IRQ_HANDLED)

 */

static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_di)

static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_gpadc)

{

	struct ab8500_gpadc *gpadc = _di;

	struct ab8500_gpadc *gpadc = _gpadc;



	complete(&gpadc->ab8500_gpadc_complete);
@@ -215,16 +238,16 @@ static int __devinit ab8500_gpadc_probe(struct platform_device *pdev) 
		return -ENOMEM;

	}



	gpadc->parent = dev_get_drvdata(pdev->dev.parent);

	gpadc->irq = platform_get_irq_byname(pdev, "SW_CONV_END");

	if (gpadc->irq < 0) {

		dev_err(gpadc->dev, "failed to get platform irq-%d\n", di->irq);

		dev_err(gpadc->dev, "failed to get platform irq-%d\n",

			gpadc->irq);

		ret = gpadc->irq;

		goto fail;

	}



	gpadc->dev = &pdev->dev;

	mutex_init(&di->ab8500_gpadc_lock);

	mutex_init(&gpadc->ab8500_gpadc_lock);



	/* Initialize completion used to notify completion of conversion */

	init_completion(&gpadc->ab8500_gpadc_complete);
@@ -246,7 +269,7 @@ static int __devinit ab8500_gpadc_probe(struct platform_device *pdev) 
		dev_err(gpadc->dev, "failed to get vtvout LDO\n");

		goto fail;

	}

	di = gpadc;

	list_add_tail(&gpadc->node, &ab8500_gpadc_list);

	dev_dbg(gpadc->dev, "probe success\n");

	return 0;

fail:
@@ -259,8 +282,10 @@ static int __devexit ab8500_gpadc_remove(struct platform_device *pdev) 
{

	struct ab8500_gpadc *gpadc = platform_get_drvdata(pdev);



	/* remove this gpadc entry from the list */

	list_del(&gpadc->node);

	/* remove interrupt  - completion of Sw ADC conversion */

	free_irq(gpadc->irq, di);

	free_irq(gpadc->irq, gpadc);

	/* disable VTVout LDO that is being used by GPADC */

	regulator_put(gpadc->regu);

	kfree(gpadc);
@@ -291,6 +316,6 @@ subsys_initcall_sync(ab8500_gpadc_init); 
module_exit(ab8500_gpadc_exit);



MODULE_LICENSE("GPL v2");

MODULE_AUTHOR("Arun R Murthy");

MODULE_AUTHOR("Arun R Murthy, Daniel Willerud");

MODULE_ALIAS("platform:ab8500_gpadc");

MODULE_DESCRIPTION("AB8500 GPADC driver");

include/linux/mfd/ab8500/ab8500-gpadc.h

+5 −1
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
 * Licensed under GPLv2.

 *

 * Author: Arun R Murthy <arun.murthy@stericsson.com>

 * Author: Daniel Willerud <daniel.willerud@stericsson.com>

 */



#ifndef	_AB8500_GPADC_H
@@ -23,6 +24,9 @@ 
#define BK_BAT_V	0x0C

#define DIE_TEMP	0x0D



int ab8500_gpadc_convert(u8 input);

struct ab8500_gpadc;



struct ab8500_gpadc *ab8500_gpadc_get(char *name);

int ab8500_gpadc_convert(struct ab8500_gpadc *gpadc, u8 input);



#endif /* _AB8500_GPADC_H */