275 lines
6.8 KiB
C
275 lines
6.8 KiB
C
/*
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* TI Touch Screen / ADC MFD driver
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*
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* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation version 2.
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*
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any
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* kind, whether express or implied; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/clk.h>
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#include <linux/regmap.h>
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#include <linux/mfd/core.h>
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#include <linux/pm_runtime.h>
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#include <linux/mfd/ti_am335x_tscadc.h>
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#include <linux/input/ti_am335x_tsc.h>
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#include <linux/platform_data/ti_am335x_adc.h>
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static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
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{
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unsigned int val;
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regmap_read(tsadc->regmap_tscadc, reg, &val);
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return val;
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}
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static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg,
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unsigned int val)
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{
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regmap_write(tsadc->regmap_tscadc, reg, val);
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}
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static const struct regmap_config tscadc_regmap_config = {
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.name = "ti_tscadc",
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.reg_bits = 32,
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.reg_stride = 4,
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.val_bits = 32,
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};
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static void tscadc_idle_config(struct ti_tscadc_dev *config)
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{
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unsigned int idleconfig;
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idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM |
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STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN;
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tscadc_writel(config, REG_IDLECONFIG, idleconfig);
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}
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static int ti_tscadc_probe(struct platform_device *pdev)
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{
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struct ti_tscadc_dev *tscadc;
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struct resource *res;
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struct clk *clk;
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struct mfd_tscadc_board *pdata = pdev->dev.platform_data;
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struct mfd_cell *cell;
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int err, ctrl;
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int clk_value, clock_rate;
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int tsc_wires, adc_channels = 0, total_channels;
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if (!pdata) {
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dev_err(&pdev->dev, "Could not find platform data\n");
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return -EINVAL;
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}
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if (pdata->adc_init)
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adc_channels = pdata->adc_init->adc_channels;
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tsc_wires = pdata->tsc_init->wires;
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total_channels = tsc_wires + adc_channels;
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if (total_channels > 8) {
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dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
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return -EINVAL;
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}
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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dev_err(&pdev->dev, "no memory resource defined.\n");
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return -EINVAL;
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}
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/* Allocate memory for device */
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tscadc = devm_kzalloc(&pdev->dev,
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sizeof(struct ti_tscadc_dev), GFP_KERNEL);
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if (!tscadc) {
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dev_err(&pdev->dev, "failed to allocate memory.\n");
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return -ENOMEM;
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}
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tscadc->dev = &pdev->dev;
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err = platform_get_irq(pdev, 0);
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if (err < 0) {
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dev_err(&pdev->dev, "no irq ID is specified.\n");
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goto ret;
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} else
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tscadc->irq = err;
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res = devm_request_mem_region(&pdev->dev,
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res->start, resource_size(res), pdev->name);
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if (!res) {
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dev_err(&pdev->dev, "failed to reserve registers.\n");
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return -EBUSY;
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}
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tscadc->tscadc_base = devm_ioremap(&pdev->dev,
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res->start, resource_size(res));
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if (!tscadc->tscadc_base) {
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dev_err(&pdev->dev, "failed to map registers.\n");
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return -ENOMEM;
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}
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tscadc->regmap_tscadc = devm_regmap_init_mmio(&pdev->dev,
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tscadc->tscadc_base, &tscadc_regmap_config);
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if (IS_ERR(tscadc->regmap_tscadc)) {
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dev_err(&pdev->dev, "regmap init failed\n");
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err = PTR_ERR(tscadc->regmap_tscadc);
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goto ret;
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}
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pm_runtime_enable(&pdev->dev);
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pm_runtime_get_sync(&pdev->dev);
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/*
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* The TSC_ADC_Subsystem has 2 clock domains
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* OCP_CLK and ADC_CLK.
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* The ADC clock is expected to run at target of 3MHz,
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* and expected to capture 12-bit data at a rate of 200 KSPS.
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* The TSC_ADC_SS controller design assumes the OCP clock is
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* at least 6x faster than the ADC clock.
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*/
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clk = clk_get(&pdev->dev, "adc_tsc_fck");
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if (IS_ERR(clk)) {
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dev_err(&pdev->dev, "failed to get TSC fck\n");
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err = PTR_ERR(clk);
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goto err_disable_clk;
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}
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clock_rate = clk_get_rate(clk);
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clk_put(clk);
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clk_value = clock_rate / ADC_CLK;
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if (clk_value < MAX_CLK_DIV) {
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dev_err(&pdev->dev, "clock input less than min clock requirement\n");
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err = -EINVAL;
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goto err_disable_clk;
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}
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/* TSCADC_CLKDIV needs to be configured to the value minus 1 */
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clk_value = clk_value - 1;
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tscadc_writel(tscadc, REG_CLKDIV, clk_value);
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/* Set the control register bits */
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ctrl = CNTRLREG_STEPCONFIGWRT |
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CNTRLREG_TSCENB |
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CNTRLREG_STEPID |
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CNTRLREG_4WIRE;
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tscadc_writel(tscadc, REG_CTRL, ctrl);
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/* Set register bits for Idle Config Mode */
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tscadc_idle_config(tscadc);
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/* Enable the TSC module enable bit */
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ctrl = tscadc_readl(tscadc, REG_CTRL);
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ctrl |= CNTRLREG_TSCSSENB;
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tscadc_writel(tscadc, REG_CTRL, ctrl);
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/* TSC Cell */
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cell = &tscadc->cells[TSC_CELL];
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cell->name = "tsc";
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cell->platform_data = tscadc;
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cell->pdata_size = sizeof(*tscadc);
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/* ADC Cell */
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cell = &tscadc->cells[ADC_CELL];
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cell->name = "tiadc";
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cell->platform_data = tscadc;
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cell->pdata_size = sizeof(*tscadc);
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err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
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TSCADC_CELLS, NULL, 0, NULL);
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if (err < 0)
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goto err_disable_clk;
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device_init_wakeup(&pdev->dev, true);
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platform_set_drvdata(pdev, tscadc);
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return 0;
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err_disable_clk:
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pm_runtime_put_sync(&pdev->dev);
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pm_runtime_disable(&pdev->dev);
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ret:
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return err;
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}
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static int ti_tscadc_remove(struct platform_device *pdev)
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{
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struct ti_tscadc_dev *tscadc = platform_get_drvdata(pdev);
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tscadc_writel(tscadc, REG_SE, 0x00);
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pm_runtime_put_sync(&pdev->dev);
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pm_runtime_disable(&pdev->dev);
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mfd_remove_devices(tscadc->dev);
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return 0;
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}
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#ifdef CONFIG_PM
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static int tscadc_suspend(struct device *dev)
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{
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struct ti_tscadc_dev *tscadc_dev = dev_get_drvdata(dev);
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tscadc_writel(tscadc_dev, REG_SE, 0x00);
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pm_runtime_put_sync(dev);
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return 0;
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}
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static int tscadc_resume(struct device *dev)
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{
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struct ti_tscadc_dev *tscadc_dev = dev_get_drvdata(dev);
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unsigned int restore, ctrl;
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pm_runtime_get_sync(dev);
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/* context restore */
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ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_TSCENB |
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CNTRLREG_STEPID | CNTRLREG_4WIRE;
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tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
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tscadc_idle_config(tscadc_dev);
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tscadc_writel(tscadc_dev, REG_SE, STPENB_STEPENB);
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restore = tscadc_readl(tscadc_dev, REG_CTRL);
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tscadc_writel(tscadc_dev, REG_CTRL,
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(restore | CNTRLREG_TSCSSENB));
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return 0;
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}
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static const struct dev_pm_ops tscadc_pm_ops = {
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.suspend = tscadc_suspend,
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.resume = tscadc_resume,
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};
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#define TSCADC_PM_OPS (&tscadc_pm_ops)
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#else
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#define TSCADC_PM_OPS NULL
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#endif
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static struct platform_driver ti_tscadc_driver = {
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.driver = {
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.name = "ti_tscadc",
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.owner = THIS_MODULE,
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.pm = TSCADC_PM_OPS,
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},
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.probe = ti_tscadc_probe,
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.remove = ti_tscadc_remove,
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};
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module_platform_driver(ti_tscadc_driver);
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MODULE_DESCRIPTION("TI touchscreen / ADC MFD controller driver");
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MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
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MODULE_LICENSE("GPL");
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