[PATCH 1/5] input: touchscreen: add imx6ul_tsc driver support
Dmitry Torokhov
dmitry.torokhov at gmail.com
Mon Jul 27 15:05:11 PDT 2015
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().
> + int value;
Why do we need this?
> + 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()?
> + if (!tsc) {
> + err = -ENOMEM;
> + goto err_free_mem_tsc;
> + }
> +
> + input_dev = input_allocate_device();
devm_input_allocate_device(&pdev->dev)?
> + 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?
> + 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?
> + 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.
> + 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.
> +{
> + 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?
> + 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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