297 lines
8.1 KiB
C
297 lines
8.1 KiB
C
![]() |
/*
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* Copyright (C) ST-Ericsson SA 2010
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*
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* License Terms: GNU General Public License v2
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* Author: Arun R Murthy <arun.murthy@stericsson.com>
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/interrupt.h>
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#include <linux/spinlock.h>
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#include <linux/delay.h>
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#include <linux/platform_device.h>
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#include <linux/completion.h>
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#include <linux/regulator/consumer.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/mfd/ab8500.h>
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#include <linux/mfd/abx500.h>
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#include <linux/mfd/ab8500-gpadc.h>
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/*
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* GPADC register offsets
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* Bank : 0x0A
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*/
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#define AB8500_GPADC_CTRL1_REG 0x00
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#define AB8500_GPADC_CTRL2_REG 0x01
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#define AB8500_GPADC_CTRL3_REG 0x02
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#define AB8500_GPADC_AUTO_TIMER_REG 0x03
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#define AB8500_GPADC_STAT_REG 0x04
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#define AB8500_GPADC_MANDATAL_REG 0x05
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#define AB8500_GPADC_MANDATAH_REG 0x06
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#define AB8500_GPADC_AUTODATAL_REG 0x07
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#define AB8500_GPADC_AUTODATAH_REG 0x08
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#define AB8500_GPADC_MUX_CTRL_REG 0x09
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/* gpadc constants */
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#define EN_VINTCORE12 0x04
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#define EN_VTVOUT 0x02
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#define EN_GPADC 0x01
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#define DIS_GPADC 0x00
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#define SW_AVG_16 0x60
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#define ADC_SW_CONV 0x04
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#define EN_BUF 0x40
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#define DIS_ZERO 0x00
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#define GPADC_BUSY 0x01
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/**
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* struct ab8500_gpadc - ab8500 GPADC device information
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* @dev: pointer to the struct device
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* @parent: pointer to the parent device structure ab8500
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* @ab8500_gpadc_complete: pointer to the struct completion, to indicate
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* the completion of gpadc conversion
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* @ab8500_gpadc_lock: structure of type mutex
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* @regu: pointer to the struct regulator
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* @irq: interrupt number that is used by gpadc
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*/
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static struct ab8500_gpadc {
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struct device *dev;
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struct ab8500 *parent;
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struct completion ab8500_gpadc_complete;
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struct mutex ab8500_gpadc_lock;
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struct regulator *regu;
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int irq;
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} *di;
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/**
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* ab8500_gpadc_convert() - gpadc conversion
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* @input: analog input to be converted to digital data
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*
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* This function converts the selected analog i/p to digital
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* data. Thereafter calibration has to be made to obtain the
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* data in the required quantity measurement.
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*/
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int ab8500_gpadc_convert(u8 input)
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{
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int ret;
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u16 data = 0;
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int looplimit = 0;
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u8 val, low_data, high_data;
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if (!di)
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return -ENODEV;
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mutex_lock(&di->ab8500_gpadc_lock);
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/* Enable VTVout LDO this is required for GPADC */
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regulator_enable(di->regu);
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/* Check if ADC is not busy, lock and proceed */
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do {
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ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,
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AB8500_GPADC_STAT_REG, &val);
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if (ret < 0)
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goto out;
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if (!(val & GPADC_BUSY))
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break;
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msleep(10);
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} while (++looplimit < 10);
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if (looplimit >= 10 && (val & GPADC_BUSY)) {
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dev_err(di->dev, "gpadc_conversion: GPADC busy");
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ret = -EINVAL;
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goto out;
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}
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/* Enable GPADC */
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ret = abx500_mask_and_set_register_interruptible(di->dev, AB8500_GPADC,
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AB8500_GPADC_CTRL1_REG, EN_GPADC, EN_GPADC);
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if (ret < 0) {
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dev_err(di->dev, "gpadc_conversion: enable gpadc failed\n");
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goto out;
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}
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/* Select the input source and set average samples to 16 */
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ret = abx500_set_register_interruptible(di->dev, AB8500_GPADC,
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AB8500_GPADC_CTRL2_REG, (input | SW_AVG_16));
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if (ret < 0) {
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dev_err(di->dev,
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"gpadc_conversion: set avg samples failed\n");
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goto out;
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}
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/* Enable ADC, Buffering and select rising edge, start Conversion */
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ret = abx500_mask_and_set_register_interruptible(di->dev, AB8500_GPADC,
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AB8500_GPADC_CTRL1_REG, EN_BUF, EN_BUF);
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if (ret < 0) {
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dev_err(di->dev,
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"gpadc_conversion: select falling edge failed\n");
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goto out;
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}
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ret = abx500_mask_and_set_register_interruptible(di->dev, AB8500_GPADC,
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AB8500_GPADC_CTRL1_REG, ADC_SW_CONV, ADC_SW_CONV);
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if (ret < 0) {
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dev_err(di->dev,
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"gpadc_conversion: start s/w conversion failed\n");
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goto out;
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}
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/* wait for completion of conversion */
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if (!wait_for_completion_timeout(&di->ab8500_gpadc_complete, 2*HZ)) {
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dev_err(di->dev,
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"timeout: didnt recieve GPADC conversion interrupt\n");
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ret = -EINVAL;
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goto out;
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}
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/* Read the converted RAW data */
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ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,
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AB8500_GPADC_MANDATAL_REG, &low_data);
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if (ret < 0) {
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dev_err(di->dev, "gpadc_conversion: read low data failed\n");
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goto out;
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}
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ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,
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AB8500_GPADC_MANDATAH_REG, &high_data);
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if (ret < 0) {
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dev_err(di->dev, "gpadc_conversion: read high data failed\n");
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goto out;
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}
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data = (high_data << 8) | low_data;
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/* Disable GPADC */
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ret = abx500_set_register_interruptible(di->dev, AB8500_GPADC,
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AB8500_GPADC_CTRL1_REG, DIS_GPADC);
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if (ret < 0) {
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dev_err(di->dev, "gpadc_conversion: disable gpadc failed\n");
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goto out;
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}
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/* Disable VTVout LDO this is required for GPADC */
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regulator_disable(di->regu);
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mutex_unlock(&di->ab8500_gpadc_lock);
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return data;
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out:
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/*
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* It has shown to be needed to turn off the GPADC if an error occurs,
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* otherwise we might have problem when waiting for the busy bit in the
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* GPADC status register to go low. In V1.1 there wait_for_completion
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* seems to timeout when waiting for an interrupt.. Not seen in V2.0
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*/
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(void) abx500_set_register_interruptible(di->dev, AB8500_GPADC,
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AB8500_GPADC_CTRL1_REG, DIS_GPADC);
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regulator_disable(di->regu);
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mutex_unlock(&di->ab8500_gpadc_lock);
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dev_err(di->dev, "gpadc_conversion: Failed to AD convert channel %d\n",
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input);
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return ret;
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}
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EXPORT_SYMBOL(ab8500_gpadc_convert);
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/**
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* ab8500_bm_gpswadcconvend_handler() - isr for s/w gpadc conversion completion
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* @irq: irq number
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* @data: pointer to the data passed during request irq
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*
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* This is a interrupt service routine for s/w gpadc conversion completion.
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* Notifies the gpadc completion is completed and the converted raw value
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* can be read from the registers.
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* Returns IRQ status(IRQ_HANDLED)
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*/
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static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_di)
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{
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struct ab8500_gpadc *gpadc = _di;
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complete(&gpadc->ab8500_gpadc_complete);
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return IRQ_HANDLED;
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}
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static int __devinit ab8500_gpadc_probe(struct platform_device *pdev)
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{
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int ret = 0;
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struct ab8500_gpadc *gpadc;
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gpadc = kzalloc(sizeof(struct ab8500_gpadc), GFP_KERNEL);
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if (!gpadc) {
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dev_err(&pdev->dev, "Error: No memory\n");
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return -ENOMEM;
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}
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gpadc->parent = dev_get_drvdata(pdev->dev.parent);
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gpadc->irq = platform_get_irq_byname(pdev, "SW_CONV_END");
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if (gpadc->irq < 0) {
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dev_err(gpadc->dev, "failed to get platform irq-%d\n", di->irq);
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ret = gpadc->irq;
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goto fail;
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}
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gpadc->dev = &pdev->dev;
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mutex_init(&di->ab8500_gpadc_lock);
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/* Initialize completion used to notify completion of conversion */
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init_completion(&gpadc->ab8500_gpadc_complete);
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/* Register interrupt - SwAdcComplete */
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ret = request_threaded_irq(gpadc->irq, NULL,
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ab8500_bm_gpswadcconvend_handler,
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IRQF_NO_SUSPEND | IRQF_SHARED, "ab8500-gpadc", gpadc);
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if (ret < 0) {
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dev_err(gpadc->dev, "Failed to register interrupt, irq: %d\n",
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gpadc->irq);
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goto fail;
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}
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/* VTVout LDO used to power up ab8500-GPADC */
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gpadc->regu = regulator_get(&pdev->dev, "vddadc");
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if (IS_ERR(gpadc->regu)) {
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ret = PTR_ERR(gpadc->regu);
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dev_err(gpadc->dev, "failed to get vtvout LDO\n");
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goto fail;
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}
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di = gpadc;
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dev_dbg(gpadc->dev, "probe success\n");
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return 0;
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fail:
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kfree(gpadc);
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gpadc = NULL;
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return ret;
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}
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static int __devexit ab8500_gpadc_remove(struct platform_device *pdev)
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{
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struct ab8500_gpadc *gpadc = platform_get_drvdata(pdev);
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/* remove interrupt - completion of Sw ADC conversion */
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free_irq(gpadc->irq, di);
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/* disable VTVout LDO that is being used by GPADC */
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regulator_put(gpadc->regu);
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kfree(gpadc);
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gpadc = NULL;
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return 0;
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}
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static struct platform_driver ab8500_gpadc_driver = {
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.probe = ab8500_gpadc_probe,
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.remove = __devexit_p(ab8500_gpadc_remove),
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.driver = {
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.name = "ab8500-gpadc",
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.owner = THIS_MODULE,
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},
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};
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static int __init ab8500_gpadc_init(void)
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{
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return platform_driver_register(&ab8500_gpadc_driver);
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}
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static void __exit ab8500_gpadc_exit(void)
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{
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platform_driver_unregister(&ab8500_gpadc_driver);
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}
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subsys_initcall_sync(ab8500_gpadc_init);
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module_exit(ab8500_gpadc_exit);
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Arun R Murthy");
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MODULE_ALIAS("platform:ab8500_gpadc");
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MODULE_DESCRIPTION("AB8500 GPADC driver");
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