forked from mirrors/linux
		
	Use devm_* api to simplify code, this makes it unnecessary to explicitly release resources. Signed-off-by: Yangtao Li <frank.li@vivo.com> Link: https://lore.kernel.org/r/20230705052346.39337-10-frank.li@vivo.com Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
		
			
				
	
	
		
			345 lines
		
	
	
	
		
			8.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			345 lines
		
	
	
	
		
			8.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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 * LPC32xx built-in touchscreen driver
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 *
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 * Copyright (C) 2010 NXP Semiconductors
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 */
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#include <linux/platform_device.h>
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#include <linux/input.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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/*
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 * Touchscreen controller register offsets
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 */
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#define LPC32XX_TSC_STAT			0x00
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#define LPC32XX_TSC_SEL				0x04
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#define LPC32XX_TSC_CON				0x08
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#define LPC32XX_TSC_FIFO			0x0C
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#define LPC32XX_TSC_DTR				0x10
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#define LPC32XX_TSC_RTR				0x14
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#define LPC32XX_TSC_UTR				0x18
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#define LPC32XX_TSC_TTR				0x1C
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#define LPC32XX_TSC_DXP				0x20
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#define LPC32XX_TSC_MIN_X			0x24
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#define LPC32XX_TSC_MAX_X			0x28
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#define LPC32XX_TSC_MIN_Y			0x2C
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#define LPC32XX_TSC_MAX_Y			0x30
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#define LPC32XX_TSC_AUX_UTR			0x34
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#define LPC32XX_TSC_AUX_MIN			0x38
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#define LPC32XX_TSC_AUX_MAX			0x3C
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#define LPC32XX_TSC_STAT_FIFO_OVRRN		BIT(8)
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#define LPC32XX_TSC_STAT_FIFO_EMPTY		BIT(7)
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#define LPC32XX_TSC_SEL_DEFVAL			0x0284
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#define LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4	(0x1 << 11)
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#define LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(s)	((10 - (s)) << 7)
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#define LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(s)	((10 - (s)) << 4)
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#define LPC32XX_TSC_ADCCON_POWER_UP		BIT(2)
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#define LPC32XX_TSC_ADCCON_AUTO_EN		BIT(0)
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#define LPC32XX_TSC_FIFO_TS_P_LEVEL		BIT(31)
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#define LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(x)	(((x) & 0x03FF0000) >> 16)
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#define LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(y)	((y) & 0x000003FF)
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#define LPC32XX_TSC_ADCDAT_VALUE_MASK		0x000003FF
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#define LPC32XX_TSC_MIN_XY_VAL			0x0
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#define LPC32XX_TSC_MAX_XY_VAL			0x3FF
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#define MOD_NAME "ts-lpc32xx"
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#define tsc_readl(dev, reg) \
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	__raw_readl((dev)->tsc_base + (reg))
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#define tsc_writel(dev, reg, val) \
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	__raw_writel((val), (dev)->tsc_base + (reg))
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struct lpc32xx_tsc {
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	struct input_dev *dev;
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	void __iomem *tsc_base;
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	int irq;
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	struct clk *clk;
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};
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static void lpc32xx_fifo_clear(struct lpc32xx_tsc *tsc)
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{
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	while (!(tsc_readl(tsc, LPC32XX_TSC_STAT) &
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			LPC32XX_TSC_STAT_FIFO_EMPTY))
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		tsc_readl(tsc, LPC32XX_TSC_FIFO);
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}
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static irqreturn_t lpc32xx_ts_interrupt(int irq, void *dev_id)
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{
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	u32 tmp, rv[4], xs[4], ys[4];
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	int idx;
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	struct lpc32xx_tsc *tsc = dev_id;
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	struct input_dev *input = tsc->dev;
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	tmp = tsc_readl(tsc, LPC32XX_TSC_STAT);
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	if (tmp & LPC32XX_TSC_STAT_FIFO_OVRRN) {
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		/* FIFO overflow - throw away samples */
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		lpc32xx_fifo_clear(tsc);
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		return IRQ_HANDLED;
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	}
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	/*
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	 * Gather and normalize 4 samples. Pen-up events may have less
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	 * than 4 samples, but its ok to pop 4 and let the last sample
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	 * pen status check drop the samples.
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	 */
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	idx = 0;
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	while (idx < 4 &&
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	       !(tsc_readl(tsc, LPC32XX_TSC_STAT) &
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			LPC32XX_TSC_STAT_FIFO_EMPTY)) {
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		tmp = tsc_readl(tsc, LPC32XX_TSC_FIFO);
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		xs[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
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			LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(tmp);
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		ys[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
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			LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(tmp);
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		rv[idx] = tmp;
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		idx++;
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	}
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	/* Data is only valid if pen is still down in last sample */
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	if (!(rv[3] & LPC32XX_TSC_FIFO_TS_P_LEVEL) && idx == 4) {
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		/* Use average of 2nd and 3rd sample for position */
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		input_report_abs(input, ABS_X, (xs[1] + xs[2]) / 2);
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		input_report_abs(input, ABS_Y, (ys[1] + ys[2]) / 2);
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		input_report_key(input, BTN_TOUCH, 1);
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	} else {
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		input_report_key(input, BTN_TOUCH, 0);
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	}
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	input_sync(input);
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	return IRQ_HANDLED;
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}
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static void lpc32xx_stop_tsc(struct lpc32xx_tsc *tsc)
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{
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	/* Disable auto mode */
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	tsc_writel(tsc, LPC32XX_TSC_CON,
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		   tsc_readl(tsc, LPC32XX_TSC_CON) &
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			     ~LPC32XX_TSC_ADCCON_AUTO_EN);
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	clk_disable_unprepare(tsc->clk);
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}
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static int lpc32xx_setup_tsc(struct lpc32xx_tsc *tsc)
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{
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	u32 tmp;
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	int err;
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	err = clk_prepare_enable(tsc->clk);
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	if (err)
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		return err;
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	tmp = tsc_readl(tsc, LPC32XX_TSC_CON) & ~LPC32XX_TSC_ADCCON_POWER_UP;
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	/* Set the TSC FIFO depth to 4 samples @ 10-bits per sample (max) */
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	tmp = LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4 |
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	      LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(10) |
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	      LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(10);
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	tsc_writel(tsc, LPC32XX_TSC_CON, tmp);
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	/* These values are all preset */
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	tsc_writel(tsc, LPC32XX_TSC_SEL, LPC32XX_TSC_SEL_DEFVAL);
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	tsc_writel(tsc, LPC32XX_TSC_MIN_X, LPC32XX_TSC_MIN_XY_VAL);
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	tsc_writel(tsc, LPC32XX_TSC_MAX_X, LPC32XX_TSC_MAX_XY_VAL);
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	tsc_writel(tsc, LPC32XX_TSC_MIN_Y, LPC32XX_TSC_MIN_XY_VAL);
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	tsc_writel(tsc, LPC32XX_TSC_MAX_Y, LPC32XX_TSC_MAX_XY_VAL);
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	/* Aux support is not used */
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	tsc_writel(tsc, LPC32XX_TSC_AUX_UTR, 0);
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	tsc_writel(tsc, LPC32XX_TSC_AUX_MIN, 0);
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	tsc_writel(tsc, LPC32XX_TSC_AUX_MAX, 0);
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	/*
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	 * Set sample rate to about 240Hz per X/Y pair. A single measurement
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	 * consists of 4 pairs which gives about a 60Hz sample rate based on
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	 * a stable 32768Hz clock source. Values are in clocks.
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	 * Rate is (32768 / (RTR + XCONV + RTR + YCONV + DXP + TTR + UTR) / 4
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	 */
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	tsc_writel(tsc, LPC32XX_TSC_RTR, 0x2);
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	tsc_writel(tsc, LPC32XX_TSC_DTR, 0x2);
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	tsc_writel(tsc, LPC32XX_TSC_TTR, 0x10);
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	tsc_writel(tsc, LPC32XX_TSC_DXP, 0x4);
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	tsc_writel(tsc, LPC32XX_TSC_UTR, 88);
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	lpc32xx_fifo_clear(tsc);
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	/* Enable automatic ts event capture */
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	tsc_writel(tsc, LPC32XX_TSC_CON, tmp | LPC32XX_TSC_ADCCON_AUTO_EN);
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	return 0;
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}
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static int lpc32xx_ts_open(struct input_dev *dev)
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{
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	struct lpc32xx_tsc *tsc = input_get_drvdata(dev);
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	return lpc32xx_setup_tsc(tsc);
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}
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static void lpc32xx_ts_close(struct input_dev *dev)
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{
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	struct lpc32xx_tsc *tsc = input_get_drvdata(dev);
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	lpc32xx_stop_tsc(tsc);
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}
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static int lpc32xx_ts_probe(struct platform_device *pdev)
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{
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	struct device *dev = &pdev->dev;
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	struct lpc32xx_tsc *tsc;
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	struct input_dev *input;
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	int irq;
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	int error;
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	irq = platform_get_irq(pdev, 0);
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	if (irq < 0)
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		return irq;
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	tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
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	if (!tsc)
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		return -ENOMEM;
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	tsc->irq = irq;
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	tsc->tsc_base = devm_platform_ioremap_resource(pdev, 0);
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	if (IS_ERR(tsc->tsc_base))
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		return PTR_ERR(tsc->tsc_base);
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	tsc->clk = devm_clk_get(dev, NULL);
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	if (IS_ERR(tsc->clk)) {
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		dev_err(&pdev->dev, "failed getting clock\n");
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		return PTR_ERR(tsc->clk);
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	}
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	input = devm_input_allocate_device(dev);
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	if (!input) {
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		dev_err(&pdev->dev, "failed allocating input device\n");
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		return -ENOMEM;
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	}
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	input->name = MOD_NAME;
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	input->phys = "lpc32xx/input0";
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	input->id.bustype = BUS_HOST;
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	input->id.vendor = 0x0001;
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	input->id.product = 0x0002;
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	input->id.version = 0x0100;
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	input->open = lpc32xx_ts_open;
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	input->close = lpc32xx_ts_close;
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	input_set_capability(input, EV_KEY, BTN_TOUCH);
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	input_set_abs_params(input, ABS_X, LPC32XX_TSC_MIN_XY_VAL,
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			     LPC32XX_TSC_MAX_XY_VAL, 0, 0);
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	input_set_abs_params(input, ABS_Y, LPC32XX_TSC_MIN_XY_VAL,
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			     LPC32XX_TSC_MAX_XY_VAL, 0, 0);
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	input_set_drvdata(input, tsc);
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	tsc->dev = input;
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	error = devm_request_irq(dev, tsc->irq, lpc32xx_ts_interrupt,
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				 0, pdev->name, tsc);
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	if (error) {
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		dev_err(&pdev->dev, "failed requesting interrupt\n");
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		return error;
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	}
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	error = input_register_device(input);
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	if (error) {
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		dev_err(&pdev->dev, "failed registering input device\n");
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		return error;
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	}
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	platform_set_drvdata(pdev, tsc);
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	device_init_wakeup(&pdev->dev, true);
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	return 0;
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}
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#ifdef CONFIG_PM
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static int lpc32xx_ts_suspend(struct device *dev)
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{
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	struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
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	struct input_dev *input = tsc->dev;
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	/*
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	 * Suspend and resume can be called when the device hasn't been
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	 * enabled. If there are no users that have the device open, then
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	 * avoid calling the TSC stop and start functions as the TSC
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	 * isn't yet clocked.
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	 */
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	mutex_lock(&input->mutex);
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	if (input_device_enabled(input)) {
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		if (device_may_wakeup(dev))
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			enable_irq_wake(tsc->irq);
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		else
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			lpc32xx_stop_tsc(tsc);
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	}
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	mutex_unlock(&input->mutex);
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	return 0;
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}
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static int lpc32xx_ts_resume(struct device *dev)
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{
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	struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
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	struct input_dev *input = tsc->dev;
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	mutex_lock(&input->mutex);
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	if (input_device_enabled(input)) {
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		if (device_may_wakeup(dev))
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			disable_irq_wake(tsc->irq);
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		else
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			lpc32xx_setup_tsc(tsc);
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	}
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	mutex_unlock(&input->mutex);
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	return 0;
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}
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static const struct dev_pm_ops lpc32xx_ts_pm_ops = {
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	.suspend	= lpc32xx_ts_suspend,
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	.resume		= lpc32xx_ts_resume,
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};
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#define LPC32XX_TS_PM_OPS (&lpc32xx_ts_pm_ops)
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#else
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#define LPC32XX_TS_PM_OPS NULL
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#endif
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#ifdef CONFIG_OF
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static const struct of_device_id lpc32xx_tsc_of_match[] = {
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	{ .compatible = "nxp,lpc3220-tsc", },
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	{ },
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};
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MODULE_DEVICE_TABLE(of, lpc32xx_tsc_of_match);
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#endif
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static struct platform_driver lpc32xx_ts_driver = {
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	.probe		= lpc32xx_ts_probe,
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	.driver		= {
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		.name	= MOD_NAME,
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		.pm	= LPC32XX_TS_PM_OPS,
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		.of_match_table = of_match_ptr(lpc32xx_tsc_of_match),
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	},
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};
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module_platform_driver(lpc32xx_ts_driver);
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MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com");
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MODULE_DESCRIPTION("LPC32XX TSC Driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:lpc32xx_ts");
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