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.c...@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.c...@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.torok...@gmail.com>

Signed-off-by: Dmitry Torokhov <dmitry.torok...@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);
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to