[PATCH v2 1/5] input: touchscreen: add imx6ul_tsc driver support

Chen Bough Haibo.Chen at freescale.com
Fri Aug 21 01:08:46 PDT 2015


Hi Dmitry,

Thanks for your patient review, especially for the patch you attached.

I test your patch these days, with below change, touch can work normally.
(also change the xnur to active low in dts)

In probe function:

> -	tsc->xnur_gpio = of_get_named_gpio(np, "xnur-gpio", 0);
> -	err = gpio_request_one(tsc->xnur_gpio, GPIOF_IN, "tsc_X-");
> -	if (err) {
> -		dev_err(&pdev->dev, "failed to request GPIO tsc_X-\n");
> +	input_set_drvdata(input_dev, tsc);
> +
> +	tsc->dev = &pdev->dev;
> +	tsc->input = input_dev;
> +	init_completion(&tsc->completion);
> +
> +	tsc->xnur_gpio = devm_gpiod_get(&pdev->dev, "xnur-gpio", GPIOD_IN);  

Here, we need to change "xnur-gpio" to "xnur", otherwise the gpio request will be failed.
This is because gpiod common code already add suffix '-gpio' or 'gpios'.  



For others, your patch seems normal and rational. I will add your patch and send patch-V3.

Thanks again!


Best Regards
Haibo Chen



> -----Original Message-----
> From: Dmitry Torokhov [mailto:dmitry.torokhov at gmail.com]
> Sent: Wednesday, August 19, 2015 1:12 PM
> To: Chen Haibo-B51421
> Cc: robh+dt at kernel.org; pawel.moll at arm.com; mark.rutland at arm.com;
> ijc+devicetree at hellion.org.uk; galak at codeaurora.org; shawnguo at kernel.org;
> kernel at pengutronix.de; linux at arm.linux.org.uk; hans.verkuil at cisco.com;
> hadess at hadess.net; mchehab at osg.samsung.com; mamlinav at gmail.com;
> arnd at arndb.de; jonathar at broadcom.com; hdegoede at redhat.com;
> christian.gmeiner at gmail.com; scott.liu at emc.com.tw; geert at linux-m68k.org;
> benjamin.tissoires at redhat.com; sebastien.szymanski at armadeus.com;
> sbranden at broadcom.com; devicetree at vger.kernel.org; linux-
> kernel at vger.kernel.org; linux-arm-kernel at lists.infradead.org; linux-
> input at vger.kernel.org
> Subject: Re: [PATCH v2 1/5] input: touchscreen: add imx6ul_tsc driver
> support
> 
> Hi Haibo,
> 
> On Tue, Jul 28, 2015 at 05:58:37PM +0800, Haibo Chen wrote:
> > Freescale i.MX6UL contains a internal touchscreen controller, this
> > patch add a driver to support this controller.
> >
> 
> This looks pretty reasonable; just a few comments below.
> 
> > Signed-off-by: Haibo Chen <haibo.chen at freescale.com>
> > ---
> >  drivers/input/touchscreen/Kconfig      |  12 +
> >  drivers/input/touchscreen/Makefile     |   1 +
> >  drivers/input/touchscreen/imx6ul_tsc.c | 504
> > +++++++++++++++++++++++++++++++++
> >  3 files changed, 517 insertions(+)
> >  create mode 100644 drivers/input/touchscreen/imx6ul_tsc.c
> >
> > diff --git a/drivers/input/touchscreen/Kconfig
> > b/drivers/input/touchscreen/Kconfig
> > index 5b272ba..32c300d 100644
> > --- a/drivers/input/touchscreen/Kconfig
> > +++ b/drivers/input/touchscreen/Kconfig
> > @@ -479,6 +479,18 @@ config TOUCHSCREEN_MTOUCH
> >  	  To compile this driver as a module, choose M here: the
> >  	  module will be called mtouch.
> >
> > +config TOUCHSCREEN_IMX6UL_TSC
> > +	tristate "Freescale i.MX6UL touchscreen controller"
> > +	depends on OF
> > +	help
> > +	  Say Y here if you have a Freescale i.MX6UL, and want to
> > +	  use the internal touchscreen controller.
> > +
> > +	  If unsure, say N.
> > +
> > +	  To compile this driver as a module, choose M here: the
> > +	  moduel will be called imx6ul_tsc.
> > +
> >  config TOUCHSCREEN_INEXIO
> >  	tristate "iNexio serial touchscreens"
> >  	select SERIO
> > diff --git a/drivers/input/touchscreen/Makefile
> > b/drivers/input/touchscreen/Makefile
> > index c85aae2..9379b32 100644
> > --- a/drivers/input/touchscreen/Makefile
> > +++ b/drivers/input/touchscreen/Makefile
> > @@ -38,6 +38,7 @@ obj-$(CONFIG_TOUCHSCREEN_EGALAX)	+= egalax_ts.o
> >  obj-$(CONFIG_TOUCHSCREEN_FUJITSU)	+= fujitsu_ts.o
> >  obj-$(CONFIG_TOUCHSCREEN_GOODIX)	+= goodix.o
> >  obj-$(CONFIG_TOUCHSCREEN_ILI210X)	+= ili210x.o
> > +obj-$(CONFIG_TOUCHSCREEN_IMX6UL_TSC)	+= imx6ul_tsc.o
> >  obj-$(CONFIG_TOUCHSCREEN_INEXIO)	+= inexio.o
> >  obj-$(CONFIG_TOUCHSCREEN_INTEL_MID)	+= intel-mid-touch.o
> >  obj-$(CONFIG_TOUCHSCREEN_IPROC)		+= bcm_iproc_tsc.o
> > diff --git a/drivers/input/touchscreen/imx6ul_tsc.c
> > b/drivers/input/touchscreen/imx6ul_tsc.c
> > new file mode 100644
> > index 0000000..807f1db
> > --- /dev/null
> > +++ b/drivers/input/touchscreen/imx6ul_tsc.c
> > @@ -0,0 +1,504 @@
> > +/*
> > + * Freescale i.MX6UL touchscreen controller driver
> > + *
> > + * Copyright (C) 2015 Freescale Semiconductor, Inc.
> > + *
> > + * This program is free software; you can redistribute it and/or
> > +modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + */
> > +
> > +#include <linux/errno.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/gpio.h>
> > +#include <linux/input.h>
> > +#include <linux/slab.h>
> > +#include <linux/completion.h>
> > +#include <linux/delay.h>
> > +#include <linux/of.h>
> > +#include <linux/of_device.h>
> > +#include <linux/of_gpio.h>
> > +#include <linux/of_irq.h>
> 
> I do not think you need of_irq and of_device.
> 
> > +#include <linux/interrupt.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/clk.h>
> > +#include <linux/io.h>
> > +
> > +/* ADC configuration registers field define */
> > +#define ADC_AIEN		(0x1 << 7)
> > +#define ADC_CONV_DISABLE	0x1F
> > +#define ADC_CAL			(0x1 << 7)
> > +#define ADC_CALF		0x2
> > +#define ADC_12BIT_MODE		(0x2 << 2)
> > +#define ADC_IPG_CLK		0x00
> > +#define ADC_CLK_DIV_8		(0x03 << 5)
> > +#define ADC_SHORT_SAMPLE_MODE	(0x0 << 4)
> > +#define ADC_HARDWARE_TRIGGER	(0x1 << 13)
> > +#define SELECT_CHANNEL_4	0x04
> > +#define SELECT_CHANNEL_1	0x01
> > +#define DISABLE_CONVERSION_INT	(0x0 << 7)
> > +
> > +/* ADC registers */
> > +#define REG_ADC_HC0		0x00
> > +#define REG_ADC_HC1		0x04
> > +#define REG_ADC_HC2		0x08
> > +#define REG_ADC_HC3		0x0C
> > +#define REG_ADC_HC4		0x10
> > +#define REG_ADC_HS		0x14
> > +#define REG_ADC_R0		0x18
> > +#define REG_ADC_CFG		0x2C
> > +#define REG_ADC_GC		0x30
> > +#define REG_ADC_GS		0x34
> > +
> > +#define ADC_TIMEOUT		msecs_to_jiffies(100)
> > +
> > +/* TSC registers */
> > +#define REG_TSC_BASIC_SETING	0x00
> > +#define REG_TSC_PRE_CHARGE_TIME	0x10
> > +#define REG_TSC_FLOW_CONTROL	0x20
> > +#define REG_TSC_MEASURE_VALUE	0x30
> > +#define REG_TSC_INT_EN		0x40
> > +#define REG_TSC_INT_SIG_EN	0x50
> > +#define REG_TSC_INT_STATUS	0x60
> > +#define REG_TSC_DEBUG_MODE	0x70
> > +#define REG_TSC_DEBUG_MODE2	0x80
> > +
> > +/* TSC configuration registers field define */
> > +#define DETECT_4_WIRE_MODE	(0x0 << 4)
> > +#define AUTO_MEASURE		0x1
> > +#define MEASURE_SIGNAL		0x1
> > +#define DETECT_SIGNAL		(0x1 << 4)
> > +#define VALID_SIGNAL		(0x1 << 8)
> > +#define MEASURE_INT_EN		0x1
> > +#define MEASURE_SIG_EN		0x1
> > +#define VALID_SIG_EN		(0x1 << 8)
> > +#define DE_GLITCH_2		(0x2 << 29)
> > +#define START_SENSE		(0x1 << 12)
> > +#define TSC_DISABLE		(0x1 << 16)
> > +#define DETECT_MODE		0x2
> > +
> > +struct imx6ul_tsc {
> > +	struct device *dev;
> > +	struct input_dev *input;
> > +	void __iomem *tsc_regs;
> > +	void __iomem *adc_regs;
> > +	struct clk *tsc_clk;
> > +	struct clk *adc_clk;
> > +
> > +	int xnur_gpio;
> > +	int measure_delay_time;
> > +	int pre_charge_time;
> > +
> > +	struct completion completion;
> > +};
> > +
> > +/*
> > + * TSC module need ADC to get the measure value. So
> > + * before config TSC, we should initialize ADC module.
> > + */
> > +static void imx6ul_adc_init(struct imx6ul_tsc *tsc) {
> > +	int adc_hc = 0;
> > +	int adc_gc;
> > +	int adc_gs;
> > +	int adc_cfg;
> > +	int timeout;
> > +
> > +	adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
> > +	adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK;
> > +	adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE;
> > +	adc_cfg &= ~ADC_HARDWARE_TRIGGER;
> > +	writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
> > +
> > +	/* enable calibration interrupt */
> > +	adc_hc |= ADC_AIEN;
> > +	adc_hc |= ADC_CONV_DISABLE;
> > +	writel(adc_hc, tsc->adc_regs + REG_ADC_HC0);
> > +
> > +	/* start ADC calibration */
> > +	adc_gc = readl(tsc->adc_regs + REG_ADC_GC);
> > +	adc_gc |= ADC_CAL;
> > +	writel(adc_gc, tsc->adc_regs + REG_ADC_GC);
> > +
> 
> Since this is called on every resume you need to reinit completion;
> probably at the beginning of this function.
> 
> > +	timeout = wait_for_completion_timeout
> > +			(&tsc->completion, ADC_TIMEOUT);
> > +	if (timeout == 0)
> > +		dev_err(tsc->dev, "Timeout for adc calibration\n");
> > +
> > +	adc_gs = readl(tsc->adc_regs + REG_ADC_GS);
> > +	if (adc_gs & ADC_CALF)
> > +		dev_err(tsc->dev, "ADC calibration failed\n");
> > +
> > +	/* TSC need the ADC work in hardware trigger */
> > +	adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
> > +	adc_cfg |= ADC_HARDWARE_TRIGGER;
> > +	writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG); }
> > +
> > +/*
> > + * This is a TSC workaround. Currently TSC misconnect two
> > + * ADC channels, this function remap channel configure for
> > + * hardware trigger.
> > + */
> > +static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc) {
> > +	int adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4;
> > +
> > +	adc_hc0 = DISABLE_CONVERSION_INT;
> > +	writel(adc_hc0, tsc->adc_regs + REG_ADC_HC0);
> > +
> > +	adc_hc1 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_4;
> > +	writel(adc_hc1, tsc->adc_regs + REG_ADC_HC1);
> > +
> > +	adc_hc2 = DISABLE_CONVERSION_INT;
> > +	writel(adc_hc2, tsc->adc_regs + REG_ADC_HC2);
> > +
> > +	adc_hc3 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_1;
> > +	writel(adc_hc3, tsc->adc_regs + REG_ADC_HC3);
> > +
> > +	adc_hc4 = DISABLE_CONVERSION_INT;
> > +	writel(adc_hc4, tsc->adc_regs + REG_ADC_HC4); }
> > +
> > +/*
> > + * TSC setting, confige the pre-charge time and measure delay time.
> > + * different touch screen may need different pre-charge time and
> > + * measure delay time.
> > + */
> > +static void imx6ul_tsc_set(struct imx6ul_tsc *tsc) {
> > +	int basic_setting = 0;
> > +	int start;
> > +
> > +	basic_setting |= tsc->measure_delay_time << 8;
> > +	basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE;
> > +	writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETING);
> > +
> > +	writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
> > +
> > +	writel(tsc->pre_charge_time, tsc->tsc_regs +
> REG_TSC_PRE_CHARGE_TIME);
> > +	writel(MEASURE_INT_EN, tsc->tsc_regs + REG_TSC_INT_EN);
> > +	writel(MEASURE_SIG_EN | VALID_SIG_EN,
> > +		tsc->tsc_regs + REG_TSC_INT_SIG_EN);
> > +
> > +	/* start sense detection */
> > +	start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
> > +	start |= START_SENSE;
> > +	start &= ~TSC_DISABLE;
> > +	writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL); }
> > +
> > +static void imx6ul_tsc_init(struct imx6ul_tsc *tsc) {
> > +	imx6ul_adc_init(tsc);
> > +	imx6ul_tsc_channel_config(tsc);
> > +	imx6ul_tsc_set(tsc);
> > +}
> > +
> > +static irqreturn_t tsc_irq_fn(int irq, void *dev_id) {
> > +	struct imx6ul_tsc *tsc = (struct imx6ul_tsc *)dev_id;
> 
> No need to cast void pointers.
> 
> > +	int status;
> > +	int value;
> > +	int x, y;
> > +	int xnur;
> > +	int debug_mode2;
> > +	int state_machine;
> > +	int start;
> > +	unsigned long timeout;
> > +
> > +	status = readl(tsc->tsc_regs + REG_TSC_INT_STATUS);
> > +
> > +	/* write 1 to clear the bit measure-signal */
> > +	writel(MEASURE_SIGNAL | DETECT_SIGNAL,
> > +		tsc->tsc_regs + REG_TSC_INT_STATUS);
> > +
> > +	/* It's a HW self-clean bit. Set this bit and start sense detection
> */
> > +	start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
> > +	start |= START_SENSE;
> > +	writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
> > +
> > +	if (status & MEASURE_SIGNAL) {
> > +		value = readl(tsc->tsc_regs + REG_TSC_MEASURE_VALUE);
> > +		x = (value >> 16) & 0x0fff;
> > +		y = value & 0x0fff;
> > +
> > +		/*
> > +		 * Delay some time(max 2ms), wait the pre-charge done.
> > +		 * After the pre-change mode, TSC go into detect mode.
> > +		 * And in detect mode, we can get the xnur gpio value.
> > +		 * If xnur is low, this means the touch screen still
> > +		 * be touched. If xnur is high, this means finger leave
> > +		 * the touch screen.
> > +		 */
> > +		timeout = jiffies + HZ/500;
> > +		do {
> > +			if (time_after(jiffies, timeout)) {
> > +				xnur = 0;
> > +				goto touch_event;
> > +			}
> > +			usleep_range(200, 400);
> > +			debug_mode2 = readl(tsc->tsc_regs +
> REG_TSC_DEBUG_MODE2);
> > +			state_machine = (debug_mode2 >> 20) & 0x7;
> > +		} while (state_machine != DETECT_MODE);
> > +		usleep_range(200, 400);
> > +
> > +		xnur = gpio_get_value(tsc->xnur_gpio);
> 
> It seems to me that this GPIO is actually active low: we reporting active
> touch as long as we read 0.
> 
> > +touch_event:
> > +		if (xnur == 0) {
> > +			input_report_key(tsc->input, BTN_TOUCH, 1);
> > +			input_report_abs(tsc->input, ABS_X, x);
> > +			input_report_abs(tsc->input, ABS_Y, y);
> > +		} else
> > +			input_report_key(tsc->input, BTN_TOUCH, 0);
> 
> If one branch has braces all of them should have braces.
> 
> > +
> > +		input_sync(tsc->input);
> > +	}
> > +
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +static irqreturn_t adc_irq_fn(int irq, void *dev_id) {
> > +	struct imx6ul_tsc *tsc = (struct imx6ul_tsc *)dev_id;
> > +	int coco;
> > +	int value;
> > +
> > +	coco = readl(tsc->adc_regs + REG_ADC_HS);
> > +	if (coco & 0x01) {
> > +		value = readl(tsc->adc_regs + REG_ADC_R0);
> > +		complete(&tsc->completion);
> > +	}
> > +
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +static const struct of_device_id imx6ul_tsc_match[] = {
> > +	{ .compatible = "fsl,imx6ul-tsc", },
> > +	{ /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, imx6ul_tsc_match);
> > +
> > +static int imx6ul_tsc_probe(struct platform_device *pdev) {
> > +	struct imx6ul_tsc *tsc;
> > +	struct resource *tsc_mem;
> > +	struct resource *adc_mem;
> > +	struct input_dev *input_dev;
> > +	struct device_node *np = pdev->dev.of_node;
> > +	int err;
> > +	int tsc_irq;
> > +	int adc_irq;
> > +
> > +	tsc = devm_kzalloc(&pdev->dev, sizeof(struct imx6ul_tsc),
> GFP_KERNEL);
> > +	input_dev = devm_input_allocate_device(&pdev->dev);
> 
> Using devm does not mean you do not need to check results of memory
> allocation.
> 
> > +
> > +	tsc->dev = &pdev->dev;
> > +
> > +	tsc->input = input_dev;
> > +	tsc->input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
> > +	tsc->input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
> > +	input_set_abs_params(tsc->input, ABS_X, 0, 0xFFF, 0, 0);
> > +	input_set_abs_params(tsc->input, ABS_Y, 0, 0xFFF, 0, 0);
> > +
> > +	tsc->input->name = "iMX6UL TouchScreen Controller";
> > +
> > +	tsc->xnur_gpio = of_get_named_gpio(np, "xnur-gpio", 0);
> > +	err = gpio_request_one(tsc->xnur_gpio, GPIOF_IN, "tsc_X-");
> 
> Why are you not using devm for gpio? Actually, why don't you also use
> gpiod? As is you are leaking that gpio in all error paths below.
> 
> > +	if (err) {
> > +		dev_err(&pdev->dev, "failed to request GPIO tsc_X-\n");
> > +		return err;
> > +	}
> > +
> > +	tsc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +	tsc->tsc_regs = devm_ioremap_resource(&pdev->dev, tsc_mem);
> > +	if (IS_ERR(tsc->tsc_regs)) {
> > +		dev_err(&pdev->dev, "failed to remap tsc memory\n");
> > +		err = PTR_ERR(tsc->tsc_regs);
> > +		return err;
> > +	}
> > +
> > +	adc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> > +	tsc->adc_regs = devm_ioremap_resource(&pdev->dev, adc_mem);
> > +	if (IS_ERR(tsc->adc_regs)) {
> > +		dev_err(&pdev->dev, "failed to remap adc memory\n");
> > +		err = PTR_ERR(tsc->adc_regs);
> > +		return err;
> > +	}
> > +
> > +	tsc->tsc_clk = devm_clk_get(&pdev->dev, "tsc");
> > +	if (IS_ERR(tsc->tsc_clk)) {
> > +		dev_err(&pdev->dev, "failed getting tsc clock\n");
> > +		err = PTR_ERR(tsc->tsc_clk);
> > +		return err;
> > +	}
> > +
> > +	tsc->adc_clk = devm_clk_get(&pdev->dev, "adc");
> > +	if (IS_ERR(tsc->adc_clk)) {
> > +		dev_err(&pdev->dev, "failed getting adc clock\n");
> > +		err = PTR_ERR(tsc->adc_clk);
> > +		return err;
> > +	}
> > +
> > +	tsc_irq = platform_get_irq(pdev, 0);
> > +	if (tsc_irq < 0) {
> > +		dev_err(&pdev->dev, "no tsc irq resource?\n");
> > +		return tsc_irq;
> > +	}
> > +
> > +	adc_irq = platform_get_irq(pdev, 1);
> > +	if (adc_irq <= 0) {
> > +		dev_err(&pdev->dev, "no adc irq resource?\n");
> > +		return adc_irq;
> > +	}
> > +
> > +	err = devm_request_threaded_irq(tsc->dev, tsc_irq,
> > +					NULL, tsc_irq_fn,
> > +					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
> > +					dev_name(&pdev->dev), tsc);
> > +	if (err < 0) {
> > +		dev_err(&pdev->dev,
> > +			"failed requesting tsc irq %d\n",
> > +					    tsc_irq);
> > +		return err;
> > +	}
> > +
> > +	err = devm_request_irq(tsc->dev, adc_irq,
> > +				adc_irq_fn, 0,
> > +				dev_name(&pdev->dev), tsc);
> > +	if (err < 0) {
> > +		dev_err(&pdev->dev,
> > +			"failed requesting adc irq %d\n",
> > +					    adc_irq);
> > +		return err;
> > +	}
> > +
> > +	err = of_property_read_u32(np, "measure-delay-time",
> > +				&tsc->measure_delay_time);
> > +	if (err)
> > +		tsc->measure_delay_time = 0xffff;
> > +
> > +	err = of_property_read_u32(np, "pre-charge-time",
> > +				&tsc->pre_charge_time);
> > +	if (err)
> > +		tsc->pre_charge_time = 0xfff;
> > +
> > +	init_completion(&tsc->completion);
> > +
> > +	err = clk_prepare_enable(tsc->adc_clk);
> > +	if (err) {
> > +		dev_err(&pdev->dev,
> > +			"Could not prepare or enable the adc clock.\n");
> > +		return err;
> > +	}
> > +
> > +	err = clk_prepare_enable(tsc->tsc_clk);
> > +	if (err) {
> > +		dev_err(&pdev->dev,
> > +			"Could not prepare or enable the tsc clock.\n");
> > +		goto error_tsc_clk_enable;
> > +	}
> > +
> > +	err = input_register_device(tsc->input);
> > +	if (err < 0) {
> > +		dev_err(&pdev->dev, "failed to register input device\n");
> > +		err = -EIO;
> > +		goto err_input_register;
> > +	}
> > +
> > +	imx6ul_tsc_init(tsc);
> 
> Enabling clock and initializing the controller is better in open() method
> of input device. If you also implement close() you can get rid of
> remove().
> 
> > +
> > +	platform_set_drvdata(pdev, tsc);
> > +	return 0;
> > +
> > +err_input_register:
> > +	clk_disable_unprepare(tsc->tsc_clk);
> > +error_tsc_clk_enable:
> > +	clk_disable_unprepare(tsc->adc_clk);
> > +
> > +	return err;
> > +}
> > +
> > +static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc) {
> > +	int tsc_flow;
> > +	int adc_cfg;
> > +
> > +	/* TSC controller enters to idle status */
> > +	tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
> > +	tsc_flow |= TSC_DISABLE;
> > +	writel(tsc_flow, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
> > +
> > +	/* ADC controller enters to stop mode */
> > +	adc_cfg = readl(tsc->adc_regs + REG_ADC_HC0);
> > +	adc_cfg |= ADC_CONV_DISABLE;
> > +	writel(adc_cfg, tsc->adc_regs + REG_ADC_HC0); }
> > +
> > +static int imx6ul_tsc_remove(struct platform_device *pdev) {
> > +	struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
> > +
> > +	imx6ul_tsc_disable(tsc);
> > +
> > +	clk_disable_unprepare(tsc->tsc_clk);
> > +	clk_disable_unprepare(tsc->adc_clk);
> > +	input_unregister_device(tsc->input);
> > +	kfree(tsc);
> 
> Tsc is allocated with devm(), you can't kfree() it.
> > +
> > +	return 0;
> > +}
> > +
> > +static int __maybe_unused imx6ul_tsc_suspend(struct device *dev) {
> > +	struct platform_device *pdev = to_platform_device(dev);
> > +	struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
> > +
> > +	imx6ul_tsc_disable(tsc);
> > +
> > +	clk_disable_unprepare(tsc->tsc_clk);
> > +	clk_disable_unprepare(tsc->adc_clk);
> > +
> > +	return 0;
> > +}
> > +
> > +static int __maybe_unused imx6ul_tsc_resume(struct device *dev) {
> > +	struct platform_device *pdev = to_platform_device(dev);
> > +	struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
> > +	int err;
> > +
> > +	err = clk_prepare_enable(tsc->adc_clk);
> > +	if (err)
> > +		return err;
> > +
> > +	err = clk_prepare_enable(tsc->tsc_clk);
> > +	if (err) {
> > +		clk_disable_unprepare(tsc->adc_clk);
> > +		return err;
> > +	}
> > +
> > +	imx6ul_tsc_init(tsc);
> > +	return 0;
> > +}
> > +
> > +static SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops,
> > +			 imx6ul_tsc_suspend,
> > +			 imx6ul_tsc_resume);
> > +
> > +static struct platform_driver imx6ul_tsc_driver = {
> > +	.driver		= {
> > +		.name	= "imx6ul-tsc",
> > +		.owner	= THIS_MODULE,
> > +		.of_match_table	= imx6ul_tsc_match,
> > +		.pm	= &imx6ul_tsc_pm_ops,
> > +	},
> > +	.probe		= imx6ul_tsc_probe,
> > +	.remove		= imx6ul_tsc_remove,
> > +};
> > +module_platform_driver(imx6ul_tsc_driver);
> > +
> > +MODULE_AUTHOR("Haibo Chen <haibo.chen at freescale.com>");
> > +MODULE_DESCRIPTION("Freescale i.MX6UL Touchscreen controller
> > +driver"); MODULE_LICENSE("GPL v2");
> > --
> > 1.9.1
> >
> 
> Can you try the patch below and let me know if it still works (you'll
> need to adjust your DTS for xnur gpio being active low).
> 
> Thanks!
> 
> --
> Dmitry
> 
> Input: imx6ul_tsc - misc changes
> 
> From: Dmitry Torokhov <dmitry.torokhov at gmail.com>
> 
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov at gmail.com>
> ---
>  .../bindings/input/touchscreen/imx6ul_tsc.txt      |    2
>  drivers/input/touchscreen/Kconfig                  |    2
>  drivers/input/touchscreen/imx6ul_tsc.c             |  262 +++++++++++---
> ------
>  3 files changed, 143 insertions(+), 123 deletions(-)
> 
> diff --git
> a/Documentation/devicetree/bindings/input/touchscreen/imx6ul_tsc.txt
> b/Documentation/devicetree/bindings/input/touchscreen/imx6ul_tsc.txt
> index ac41c32..c933588 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/imx6ul_tsc.txt
> +++ b/Documentation/devicetree/bindings/input/touchscreen/imx6ul_tsc.txt
> @@ -29,7 +29,7 @@ Example:
>  		clock-names = "tsc", "adc";
>  		pinctrl-names = "default";
>  		pinctrl-0 = <&pinctrl_tsc>;
> -		xnur-gpio = <&gpio1 3 GPIO_ACTIVE_HIGH>;
> +		xnur-gpio = <&gpio1 3 GPIO_ACTIVE_LOW>;
>  		measure-delay-time = <0xfff>;
>  		pre-charge-time = <0xffff>;
>  		status = "okay";
> diff --git a/drivers/input/touchscreen/Kconfig
> b/drivers/input/touchscreen/Kconfig
> index 9a1a293..5ecf19b 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -481,7 +481,7 @@ config TOUCHSCREEN_MTOUCH
> 
>  config TOUCHSCREEN_IMX6UL_TSC
>  	tristate "Freescale i.MX6UL touchscreen controller"
> -	depends on OF
> +	depends on (OF && GPIOLIB) || COMPILE_TEST
>  	help
>  	  Say Y here if you have a Freescale i.MX6UL, and want to
>  	  use the internal touchscreen controller.
> diff --git a/drivers/input/touchscreen/imx6ul_tsc.c
> b/drivers/input/touchscreen/imx6ul_tsc.c
> index 807f1db..1d028ed 100644
> --- a/drivers/input/touchscreen/imx6ul_tsc.c
> +++ b/drivers/input/touchscreen/imx6ul_tsc.c
> @@ -11,15 +11,12 @@
>  #include <linux/errno.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
> -#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/input.h>
>  #include <linux/slab.h>
>  #include <linux/completion.h>
>  #include <linux/delay.h>
>  #include <linux/of.h>
> -#include <linux/of_device.h>
> -#include <linux/of_gpio.h>
> -#include <linux/of_irq.h>
>  #include <linux/interrupt.h>
>  #include <linux/platform_device.h>
>  #include <linux/clk.h>
> @@ -85,8 +82,8 @@ struct imx6ul_tsc {
>  	void __iomem *adc_regs;
>  	struct clk *tsc_clk;
>  	struct clk *adc_clk;
> +	struct gpio_desc *xnur_gpio;
> 
> -	int xnur_gpio;
>  	int measure_delay_time;
>  	int pre_charge_time;
> 
> @@ -105,6 +102,8 @@ static void imx6ul_adc_init(struct imx6ul_tsc *tsc)
>  	int adc_cfg;
>  	int timeout;
> 
> +	reinit_completion(&tsc->completion);
> +
>  	adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
>  	adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK;
>  	adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE;
> @@ -196,17 +195,33 @@ static void imx6ul_tsc_init(struct imx6ul_tsc *tsc)
>  	imx6ul_tsc_set(tsc);
>  }
> 
> +static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc)
> +{
> +	int tsc_flow;
> +	int adc_cfg;
> +
> +	/* TSC controller enters to idle status */
> +	tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
> +	tsc_flow |= TSC_DISABLE;
> +	writel(tsc_flow, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
> +
> +	/* ADC controller enters to stop mode */
> +	adc_cfg = readl(tsc->adc_regs + REG_ADC_HC0);
> +	adc_cfg |= ADC_CONV_DISABLE;
> +	writel(adc_cfg, tsc->adc_regs + REG_ADC_HC0);
> +}
> +
>  static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
>  {
>  	struct imx6ul_tsc *tsc = (struct imx6ul_tsc *)dev_id;
>  	int status;
>  	int value;
>  	int x, y;
> -	int xnur;
>  	int debug_mode2;
>  	int state_machine;
>  	int start;
>  	unsigned long timeout;
> +	bool touch;
> 
>  	status = readl(tsc->tsc_regs + REG_TSC_INT_STATUS);
> 
> @@ -235,8 +250,8 @@ static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
>  		timeout = jiffies + HZ/500;
>  		do {
>  			if (time_after(jiffies, timeout)) {
> -				xnur = 0;
> -				goto touch_event;
> +				touch = true;
> +				goto report_touch;
>  			}
>  			usleep_range(200, 400);
>  			debug_mode2 = readl(tsc->tsc_regs +
> REG_TSC_DEBUG_MODE2);
> @@ -244,14 +259,15 @@ static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
>  		} while (state_machine != DETECT_MODE);
>  		usleep_range(200, 400);
> 
> -		xnur = gpio_get_value(tsc->xnur_gpio);
> -touch_event:
> -		if (xnur == 0) {
> +		touch = gpiod_get_value_cansleep(tsc->xnur_gpio);
> +report_touch:
> +		if (touch) {
>  			input_report_key(tsc->input, BTN_TOUCH, 1);
>  			input_report_abs(tsc->input, ABS_X, x);
>  			input_report_abs(tsc->input, ABS_Y, y);
> -		} else
> +		} else {
>  			input_report_key(tsc->input, BTN_TOUCH, 0);
> +		}
> 
>  		input_sync(tsc->input);
>  	}
> @@ -261,7 +277,7 @@ touch_event:
> 
>  static irqreturn_t adc_irq_fn(int irq, void *dev_id)
>  {
> -	struct imx6ul_tsc *tsc = (struct imx6ul_tsc *)dev_id;
> +	struct imx6ul_tsc *tsc = dev_id;
>  	int coco;
>  	int value;
> 
> @@ -274,70 +290,113 @@ static irqreturn_t adc_irq_fn(int irq, void
> *dev_id)
>  	return IRQ_HANDLED;
>  }
> 
> -static const struct of_device_id imx6ul_tsc_match[] = {
> -	{ .compatible = "fsl,imx6ul-tsc", },
> -	{ /* sentinel */ }
> -};
> -MODULE_DEVICE_TABLE(of, imx6ul_tsc_match);
> +static int imx6ul_tsc_open(struct input_dev *input_dev)
> +{
> +	struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
> +	int err;
> +
> +	err = clk_prepare_enable(tsc->adc_clk);
> +	if (err) {
> +		dev_err(tsc->dev,
> +			"Could not prepare or enable the adc clock: %d\n",
> +			err);
> +		return err;
> +	}
> +
> +	err = clk_prepare_enable(tsc->tsc_clk);
> +	if (err) {
> +		dev_err(tsc->dev,
> +			"Could not prepare or enable the tsc clock: %d\n",
> +			err);
> +		clk_disable_unprepare(tsc->adc_clk);
> +		return err;
> +	}
> +
> +	imx6ul_tsc_init(tsc);
> +
> +	return 0;
> +}
> +
> +static void imx6ul_tsc_close(struct input_dev *input_dev)
> +{
> +	struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
> +
> +	imx6ul_tsc_disable(tsc);
> +
> +	clk_disable_unprepare(tsc->tsc_clk);
> +	clk_disable_unprepare(tsc->adc_clk);
> +}
> 
>  static int imx6ul_tsc_probe(struct platform_device *pdev)
>  {
> +	struct device_node *np = pdev->dev.of_node;
>  	struct imx6ul_tsc *tsc;
> +	struct input_dev *input_dev;
>  	struct resource *tsc_mem;
>  	struct resource *adc_mem;
> -	struct input_dev *input_dev;
> -	struct device_node *np = pdev->dev.of_node;
>  	int err;
>  	int tsc_irq;
>  	int adc_irq;
> 
>  	tsc = devm_kzalloc(&pdev->dev, sizeof(struct imx6ul_tsc),
> GFP_KERNEL);
> +	if (!tsc)
> +		return -ENOMEM;
> +
>  	input_dev = devm_input_allocate_device(&pdev->dev);
> +	if (!input_dev)
> +		return -ENOMEM;
> 
> -	tsc->dev = &pdev->dev;
> +	input_dev->name = "iMX6UL TouchScreen Controller";
> +	input_dev->id.bustype = BUS_HOST;
> 
> -	tsc->input = input_dev;
> -	tsc->input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
> -	tsc->input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
> -	input_set_abs_params(tsc->input, ABS_X, 0, 0xFFF, 0, 0);
> -	input_set_abs_params(tsc->input, ABS_Y, 0, 0xFFF, 0, 0);
> +	input_dev->open = imx6ul_tsc_open;
> +	input_dev->close = imx6ul_tsc_close;
> 
> -	tsc->input->name = "iMX6UL TouchScreen Controller";
> +	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
> +	input_set_abs_params(input_dev, ABS_X, 0, 0xFFF, 0, 0);
> +	input_set_abs_params(input_dev, ABS_Y, 0, 0xFFF, 0, 0);
> 
> -	tsc->xnur_gpio = of_get_named_gpio(np, "xnur-gpio", 0);
> -	err = gpio_request_one(tsc->xnur_gpio, GPIOF_IN, "tsc_X-");
> -	if (err) {
> -		dev_err(&pdev->dev, "failed to request GPIO tsc_X-\n");
> +	input_set_drvdata(input_dev, tsc);
> +
> +	tsc->dev = &pdev->dev;
> +	tsc->input = input_dev;
> +	init_completion(&tsc->completion);
> +
> +	tsc->xnur_gpio = devm_gpiod_get(&pdev->dev, "xnur-gpio", GPIOD_IN);
> +	if (IS_ERR(tsc->xnur_gpio)) {
> +		err = PTR_ERR(tsc->xnur_gpio);
> +		dev_err(&pdev->dev,
> +			"failed to request GPIO tsc_X- (xnur): %d\n", err);
>  		return err;
>  	}
> 
>  	tsc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	tsc->tsc_regs = devm_ioremap_resource(&pdev->dev, tsc_mem);
>  	if (IS_ERR(tsc->tsc_regs)) {
> -		dev_err(&pdev->dev, "failed to remap tsc memory\n");
>  		err = PTR_ERR(tsc->tsc_regs);
> +		dev_err(&pdev->dev, "failed to remap tsc memory: %d\n", err);
>  		return err;
>  	}
> 
>  	adc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>  	tsc->adc_regs = devm_ioremap_resource(&pdev->dev, adc_mem);
>  	if (IS_ERR(tsc->adc_regs)) {
> -		dev_err(&pdev->dev, "failed to remap adc memory\n");
>  		err = PTR_ERR(tsc->adc_regs);
> +		dev_err(&pdev->dev, "failed to remap adc memory: %d\n", err);
>  		return err;
>  	}
> 
>  	tsc->tsc_clk = devm_clk_get(&pdev->dev, "tsc");
>  	if (IS_ERR(tsc->tsc_clk)) {
> -		dev_err(&pdev->dev, "failed getting tsc clock\n");
>  		err = PTR_ERR(tsc->tsc_clk);
> +		dev_err(&pdev->dev, "failed getting tsc clock: %d\n", err);
>  		return err;
>  	}
> 
>  	tsc->adc_clk = devm_clk_get(&pdev->dev, "adc");
>  	if (IS_ERR(tsc->adc_clk)) {
> -		dev_err(&pdev->dev, "failed getting adc clock\n");
>  		err = PTR_ERR(tsc->adc_clk);
> +		dev_err(&pdev->dev, "failed getting adc clock: %d\n", err);
>  		return err;
>  	}
> 
> @@ -354,111 +413,61 @@ static int imx6ul_tsc_probe(struct platform_device
> *pdev)
>  	}
> 
>  	err = devm_request_threaded_irq(tsc->dev, tsc_irq,
> -					NULL, tsc_irq_fn,
> -					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
> +					NULL, tsc_irq_fn, IRQF_ONESHOT,
>  					dev_name(&pdev->dev), tsc);
> -	if (err < 0) {
> +	if (err) {
>  		dev_err(&pdev->dev,
> -			"failed requesting tsc irq %d\n",
> -					    tsc_irq);
> +			"failed requesting tsc irq %di: %d\n",
> +			tsc_irq, err);
>  		return err;
>  	}
> 
> -	err = devm_request_irq(tsc->dev, adc_irq,
> -				adc_irq_fn, 0,
> +	err = devm_request_irq(tsc->dev, adc_irq, adc_irq_fn, 0,
>  				dev_name(&pdev->dev), tsc);
> -	if (err < 0) {
> +	if (err) {
>  		dev_err(&pdev->dev,
> -			"failed requesting adc irq %d\n",
> -					    adc_irq);
> +			"failed requesting adc irq %d: %d\n",
> +			adc_irq, err);
>  		return err;
>  	}
> 
>  	err = of_property_read_u32(np, "measure-delay-time",
> -				&tsc->measure_delay_time);
> +				   &tsc->measure_delay_time);
>  	if (err)
>  		tsc->measure_delay_time = 0xffff;
> 
>  	err = of_property_read_u32(np, "pre-charge-time",
> -				&tsc->pre_charge_time);
> +				   &tsc->pre_charge_time);
>  	if (err)
>  		tsc->pre_charge_time = 0xfff;
> 
> -	init_completion(&tsc->completion);
> -
> -	err = clk_prepare_enable(tsc->adc_clk);
> +	err = input_register_device(tsc->input);
>  	if (err) {
>  		dev_err(&pdev->dev,
> -			"Could not prepare or enable the adc clock.\n");
> +			"failed to register input device: %d\n", err);
>  		return err;
>  	}
> 
> -	err = clk_prepare_enable(tsc->tsc_clk);
> -	if (err) {
> -		dev_err(&pdev->dev,
> -			"Could not prepare or enable the tsc clock.\n");
> -		goto error_tsc_clk_enable;
> -	}
> -
> -	err = input_register_device(tsc->input);
> -	if (err < 0) {
> -		dev_err(&pdev->dev, "failed to register input device\n");
> -		err = -EIO;
> -		goto err_input_register;
> -	}
> -
> -	imx6ul_tsc_init(tsc);
> -
>  	platform_set_drvdata(pdev, tsc);
>  	return 0;
> -
> -err_input_register:
> -	clk_disable_unprepare(tsc->tsc_clk);
> -error_tsc_clk_enable:
> -	clk_disable_unprepare(tsc->adc_clk);
> -
> -	return err;
> -}
> -
> -static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc)
> -{
> -	int tsc_flow;
> -	int adc_cfg;
> -
> -	/* TSC controller enters to idle status */
> -	tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
> -	tsc_flow |= TSC_DISABLE;
> -	writel(tsc_flow, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
> -
> -	/* ADC controller enters to stop mode */
> -	adc_cfg = readl(tsc->adc_regs + REG_ADC_HC0);
> -	adc_cfg |= ADC_CONV_DISABLE;
> -	writel(adc_cfg, tsc->adc_regs + REG_ADC_HC0);
> -}
> -
> -static int imx6ul_tsc_remove(struct platform_device *pdev)
> -{
> -	struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
> -
> -	imx6ul_tsc_disable(tsc);
> -
> -	clk_disable_unprepare(tsc->tsc_clk);
> -	clk_disable_unprepare(tsc->adc_clk);
> -	input_unregister_device(tsc->input);
> -	kfree(tsc);
> -
> -	return 0;
>  }
> 
>  static int __maybe_unused imx6ul_tsc_suspend(struct device *dev)
>  {
>  	struct platform_device *pdev = to_platform_device(dev);
>  	struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
> +	struct input_dev *input_dev = tsc->input;
> 
> -	imx6ul_tsc_disable(tsc);
> +	mutex_lock(&input_dev->mutex);
> 
> -	clk_disable_unprepare(tsc->tsc_clk);
> -	clk_disable_unprepare(tsc->adc_clk);
> +	if (input_dev->users) {
> +		imx6ul_tsc_disable(tsc);
> +
> +		clk_disable_unprepare(tsc->tsc_clk);
> +		clk_disable_unprepare(tsc->adc_clk);
> +	}
> +
> +	mutex_unlock(&input_dev->mutex);
> 
>  	return 0;
>  }
> @@ -467,35 +476,46 @@ static int __maybe_unused imx6ul_tsc_resume(struct
> device *dev)
>  {
>  	struct platform_device *pdev = to_platform_device(dev);
>  	struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
> -	int err;
> +	struct input_dev *input_dev = tsc->input;
> +	int retval = 0;
> 
> -	err = clk_prepare_enable(tsc->adc_clk);
> -	if (err)
> -		return err;
> +	mutex_lock(&input_dev->mutex);
> 
> -	err = clk_prepare_enable(tsc->tsc_clk);
> -	if (err) {
> -		clk_disable_unprepare(tsc->adc_clk);
> -		return err;
> +	if (input_dev->users) {
> +		retval = clk_prepare_enable(tsc->adc_clk);
> +		if (retval)
> +			goto out;
> +
> +		retval = clk_prepare_enable(tsc->tsc_clk);
> +		if (retval) {
> +			clk_disable_unprepare(tsc->adc_clk);
> +			goto out;
> +		}
> +
> +		imx6ul_tsc_init(tsc);
>  	}
> 
> -	imx6ul_tsc_init(tsc);
> -	return 0;
> +out:
> +	mutex_unlock(&input_dev->mutex);
> +	return retval;
>  }
> 
>  static SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops,
> -			 imx6ul_tsc_suspend,
> -			 imx6ul_tsc_resume);
> +			 imx6ul_tsc_suspend, imx6ul_tsc_resume);
> +
> +static const struct of_device_id imx6ul_tsc_match[] = {
> +	{ .compatible = "fsl,imx6ul-tsc", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, imx6ul_tsc_match);
> 
>  static struct platform_driver imx6ul_tsc_driver = {
>  	.driver		= {
>  		.name	= "imx6ul-tsc",
> -		.owner	= THIS_MODULE,
>  		.of_match_table	= imx6ul_tsc_match,
>  		.pm	= &imx6ul_tsc_pm_ops,
>  	},
>  	.probe		= imx6ul_tsc_probe,
> -	.remove		= imx6ul_tsc_remove,
>  };
>  module_platform_driver(imx6ul_tsc_driver);
> 



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