/*
* Copyright (C) ST-Ericsson SA 2010
*
* License Terms: GNU General Public License v2
* Author: Arun R Murthy <arun.murthy@stericsson.com>
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/completion.h>
#include <linux/regulator/consumer.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/mfd/ab8500.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/ab8500/ab8500-gpadc.h>
/*
* GPADC register offsets
* Bank : 0x0A
*/
#define AB8500_GPADC_CTRL1_REG 0x00
#define AB8500_GPADC_CTRL2_REG 0x01
#define AB8500_GPADC_CTRL3_REG 0x02
#define AB8500_GPADC_AUTO_TIMER_REG 0x03
#define AB8500_GPADC_STAT_REG 0x04
#define AB8500_GPADC_MANDATAL_REG 0x05
#define AB8500_GPADC_MANDATAH_REG 0x06
#define AB8500_GPADC_AUTODATAL_REG 0x07
#define AB8500_GPADC_AUTODATAH_REG 0x08
#define AB8500_GPADC_MUX_CTRL_REG 0x09
/* gpadc constants */
#define EN_VINTCORE12 0x04
#define EN_VTVOUT 0x02
#define EN_GPADC 0x01
#define DIS_GPADC 0x00
#define SW_AVG_16 0x60
#define ADC_SW_CONV 0x04
#define EN_BUF 0x40
#define DIS_ZERO 0x00
#define GPADC_BUSY 0x01
/**
* struct ab8500_gpadc - ab8500 GPADC device information
* @dev: pointer to the struct device
* @parent: pointer to the parent device structure ab8500
* @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 device *dev;
struct ab8500 *parent;
struct completion ab8500_gpadc_complete;
struct mutex ab8500_gpadc_lock;
struct regulator *regu;
int irq;
} *di;
/**
* ab8500_gpadc_convert() - gpadc conversion
* @input: analog input to be converted to digital data
*
* This function converts the selected analog i/p to digital
* data. Thereafter calibration has to be made to obtain the
* data in the required quantity measurement.
*/
int ab8500_gpadc_convert(u8 input)
{
int ret;
u16 data = 0;
int looplimit = 0;
u8 val, low_data, high_data;
if (!di)
return -ENODEV;
mutex_lock(&di->ab8500_gpadc_lock);
/* Enable VTVout LDO this is required for GPADC */
regulator_enable(di->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);
if (ret < 0)
goto out;
if (!(val & GPADC_BUSY))
break;
msleep(10);
} while (++looplimit < 10);
if (looplimit >= 10 && (val & GPADC_BUSY)) {
dev_err(di->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);
if (ret < 0) {
dev_err(di->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,
AB8500_GPADC_CTRL2_REG, (input | SW_AVG_16));
if (ret < 0) {
dev_err(di->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);
if (ret < 0) {
dev_err(di->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);
if (ret < 0) {
dev_err(di->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,
"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,
AB8500_GPADC_MANDATAL_REG, &low_data);
if (ret < 0) {
dev_err(di->dev, "gpadc_conversion: read low data failed\n");
goto out;
}
ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,
AB8500_GPADC_MANDATAH_REG, &high_data);
if (ret < 0) {
dev_err(di->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,
AB8500_GPADC_CTRL1_REG, DIS_GPADC);
if (ret < 0) {
dev_err(di->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);
return data;
out:
/*
* It has shown to be needed to turn off the GPADC if an error occurs,
* otherwise we might have problem when waiting for the busy bit in the
* 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,
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);
return ret;
}
EXPORT_SYMBOL(ab8500_gpadc_convert);
/**
* ab8500_bm_gpswadcconvend_handler() - isr for s/w gpadc conversion completion
* @irq: irq number
* @data: pointer to the data passed during request irq
*
* This is a interrupt service routine for s/w gpadc conversion completion.
* Notifies the gpadc completion is completed and the converted raw value
* can be read from the registers.
* Returns IRQ status(IRQ_HANDLED)
*/
static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_di)
{
struct ab8500_gpadc *gpadc = _di;
complete(&gpadc->ab8500_gpadc_complete);
return IRQ_HANDLED;
}
static int __devinit ab8500_gpadc_probe(struct platform_device *pdev)
{
int ret = 0;
struct ab8500_gpadc *gpadc;
gpadc = kzalloc(sizeof(struct ab8500_gpadc), GFP_KERNEL);
if (!gpadc) {
dev_err(&pdev->dev, "Error: No memory\n");
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);
ret = gpadc->irq;
goto fail;
}
gpadc->dev = &pdev->dev;
mutex_init(&di->ab8500_gpadc_lock);
/* Initialize completion used to notify completion of conversion */
init_completion(&gpadc->ab8500_gpadc_complete);
/* Register interrupt - SwAdcComplete */
ret = request_threaded_irq(gpadc->irq, NULL,
ab8500_bm_gpswadcconvend_handler,
IRQF_NO_SUSPEND | IRQF_SHARED, "ab8500-gpadc", gpadc);
if (ret < 0) {
dev_err(gpadc->dev, "Failed to register interrupt, irq: %d\n",
gpadc->irq);
goto fail;
}
/* VTVout LDO used to power up ab8500-GPADC */
gpadc->regu = regulator_get(&pdev->dev, "vddadc");
if (IS_ERR(gpadc->regu)) {
ret = PTR_ERR(gpadc->regu);
dev_err(gpadc->dev, "failed to get vtvout LDO\n");
goto fail;
}
di = gpadc;
dev_dbg(gpadc->dev, "probe success\n");
return 0;
fail:
kfree(gpadc);
gpadc = NULL;
return ret;
}
static int __devexit ab8500_gpadc_remove(struct platform_device *pdev)
{
struct ab8500_gpadc *gpadc = platform_get_drvdata(pdev);
/* remove interrupt - completion of Sw ADC conversion */
free_irq(gpadc->irq, di);
/* disable VTVout LDO that is being used by GPADC */
regulator_put(gpadc->regu);
kfree(gpadc);
gpadc = NULL;
return 0;
}
static struct platform_driver ab8500_gpadc_driver = {
.probe = ab8500_gpadc_probe,
.remove = __devexit_p(ab8500_gpadc_remove),
.driver = {
.name = "ab8500-gpadc",
.owner = THIS_MODULE,
},
};
static int __init ab8500_gpadc_init(void)
{
return platform_driver_register(&ab8500_gpadc_driver);
}
static void __exit ab8500_gpadc_exit(void)
{
platform_driver_unregister(&ab8500_gpadc_driver);
}
subsys_initcall_sync(ab8500_gpadc_init);
module_exit(ab8500_gpadc_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Arun R Murthy");
MODULE_ALIAS("platform:ab8500_gpadc");
MODULE_DESCRIPTION("AB8500 GPADC driver");
