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

Chen Bough Haibo.Chen at freescale.com
Tue Jul 28 02:17:49 PDT 2015


Hi Dmitry,

Thanks for your careful review! My comments is following.


Best Regards

Haibo Chen


> -----Original Message-----
> From: Dmitry Torokhov [mailto:dmitry.torokhov at gmail.com]
> Sent: Tuesday, July 28, 2015 6:05 AM
> 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 1/5] input: touchscreen: add imx6ul_tsc driver
> support
> 
> Hi Haibo,
> 
> On Mon, Jul 27, 2015 at 07:26:43PM +0800, Haibo Chen wrote:
> > Freescale i.MX6UL contains a internal touchscreen controller, this
> > patch add a driver to support this controller.
> >
> > 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 | 510
> > +++++++++++++++++++++++++++++++++
> >  3 files changed, 523 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..5a5a368
> > --- /dev/null
> > +++ b/drivers/input/touchscreen/imx6ul_tsc.c
> > @@ -0,0 +1,510 @@
> > +/*
> > + * 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>
> > +#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 tsc_irq;
> > +	int adc_irq;
> 
> You do not need to store tsc_irq and adc_irq since you do not reference
> them anywhere but in probe().
> 

[haibo] yes, you are right, I will remove these and just add these values in probe()

> > +	int value;
> 
> Why do we need this?

[haibo] in tsc_irq(), I use this value to record the tsc measure value. But now I find the value just used
In tsc_irq, so I will remove this value out of imx6ul_tsc.
> 
> > +	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);
> > +
> > +	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(int irq, void *dev_id) {
> > +	struct imx6ul_tsc *tsc = (struct imx6ul_tsc *)dev_id;
> > +	int status;
> > +	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) {
> > +		tsc->value = readl(tsc->tsc_regs + REG_TSC_MEASURE_VALUE);
> > +		x = (tsc->value >> 16) & 0x0fff;
> > +		y = tsc->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);
> > +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);
> > +
> > +		input_sync(tsc->input);
> > +	}
> > +
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +static irqreturn_t adc_irq(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;
> > +
> > +	tsc = kzalloc(sizeof(struct imx6ul_tsc), GFP_KERNEL);
> 
> Why not devm_kzalloc()?
> 

[haibo] It's better to use devm_kzalloc(), I will change this.

> > +	if (!tsc) {
> > +		err = -ENOMEM;
> > +		goto err_free_mem_tsc;
> > +	}
> > +
> > +	input_dev = input_allocate_device();
> 
> devm_input_allocate_device(&pdev->dev)?
> 

[haibo] will change this.

> 
> > +	if (!input_dev) {
> > +		err = -ENOMEM;
> > +		goto err_free_mem;
> > +	}
> > +
> > +	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-");
> > +	if (err) {
> > +		dev_err(&pdev->dev, "failed to request GPIO tsc_X-\n");
> > +		goto err_free_mem;
> > +	}
> > +
> > +	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);
> > +		goto err_free_mem;
> > +	}
> > +
> > +	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);
> > +		goto err_free_mem;
> > +	}
> > +
> > +	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);
> > +		goto err_free_mem;
> > +	}
> > +
> > +	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);
> > +		goto err_free_mem;
> > +	}
> > +
> > +	tsc->tsc_irq = platform_get_irq(pdev, 0);
> > +	if (tsc->tsc_irq <= 0) {
> > +		dev_err(&pdev->dev, "no tsc irq resource?\n");
> > +		err = -EINVAL;
> > +		goto err_free_mem;
> > +	}
> > +
> > +	tsc->adc_irq = platform_get_irq(pdev, 1);
> > +	if (tsc->adc_irq <= 0) {
> > +		dev_err(&pdev->dev, "no adc irq resource?\n");
> > +		err = -EINVAL;
> 
> I think platform_get_irq() return negative errors, so let's check for
> tsc->adc_irq < 0 and do:
> 
> 		return tsc->adc_irq?

[haibo] Good suggestion! I will take this. 

> 
> > +		goto err_free_mem;
> > +	}
> > +
> > +	err = devm_request_threaded_irq(tsc->dev, tsc->tsc_irq,
> > +					NULL, tsc_irq,
> > +					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
> 
> Do we need to hard-code the trigger? Maybe rely on board/OF code to set
> up the trigger flags properly?
> 

[haibo] this tsc is inside the imx6ul soc, it do not relay on board.
   
> > +					dev_name(&pdev->dev), tsc);
> > +	if (err < 0) {
> > +		dev_err(&pdev->dev,
> > +			"failed requesting tsc irq %d\n",
> > +					    tsc->tsc_irq);
> > +		goto err_free_mem;
> > +	}
> > +
> > +	err = devm_request_irq(tsc->dev, tsc->adc_irq,
> > +				adc_irq, 0,
> > +				dev_name(&pdev->dev), tsc);
> > +	if (err < 0) {
> > +		dev_err(&pdev->dev,
> > +			"failed requesting adc irq %d\n",
> > +					    tsc->adc_irq);
> > +		goto err_free_mem;
> > +	}
> > +
> > +	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");
> > +		goto err_free_mem;
> > +	}
> > +
> > +	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);
> > +err_free_mem:
> > +	input_free_device(tsc->input);
> > +err_free_mem_tsc:
> > +	kfree(tsc);
> > +	return err;
> > +}
> > +
> > +static int imx6ul_tsc_remove(struct platform_device *pdev) {
> > +	struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
> > +
> > +	clk_disable_unprepare(tsc->tsc_clk);
> > +	clk_disable_unprepare(tsc->adc_clk);
> 
> Just cutting clocks is not really nice. Why don't you shut down the
> device as you do in suspend, before disabling the clocks.

[haibo] Yes, you are right, it's my negligence.
> 
> > +	input_unregister_device(tsc->input);
> > +	kfree(tsc);
> > +
> > +	return 0;
> > +}
> > +
> > +#ifdef CONFIG_PM_SLEEP
> 
> Drop ifdef.
> 
> > +static int imx6ul_tsc_suspend(struct device *dev)
> 
> __maybe_unused.
> 
> > +{
> > +	struct platform_device *pdev = to_platform_device(dev);
> > +	struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
> > +	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);
> > +
> > +	clk_disable_unprepare(tsc->tsc_clk);
> > +	clk_disable_unprepare(tsc->adc_clk);
> > +
> > +	return 0;
> > +}
> > +
> > +static int imx6ul_tsc_resume(struct device *dev)
> 
> __maybe_unused.
> 

[haibo] will add this .

> > +{
> > +	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)
> 
> Disable tsc->adc_clk?
> 

[haibo] will add this.
 
> > +		return err;
> > +
> > +	imx6ul_tsc_init(tsc);
> > +	return 0;
> > +}
> > +#endif
> > +
> > +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
> >
> 
> --
> Dmitry



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