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Date: Tue, 22 Sep 2015 00:54:02 +0300
From: Aleksei Mamlin <mamlinav@...il.com>
To: Irina Tirdea <irina.tirdea@...el.com>
Cc: Dmitry Torokhov <dmitry.torokhov@...il.com>,
Bastien Nocera <hadess@...ess.net>,
linux-input@...r.kernel.org, Mark Rutland <mark.rutland@....com>,
Octavian Purdila <octavian.purdila@...el.com>,
linux-kernel@...r.kernel.org, devicetree@...r.kernel.org
Subject: Re: [PATCH v6 3/9] Input: goodix - reset device at init
On Tue, 15 Sep 2015 17:31:17 +0300
Irina Tirdea <irina.tirdea@...el.com> wrote:
> After power on, it is recommended that the driver resets the device.
> The reset procedure timing is described in the datasheet and is used
> at device init (before writing device configuration) and
> for power management. It is a sequence of setting the interrupt
> and reset pins high/low at specific timing intervals. This procedure
> also includes setting the slave address to the one specified in the
> ACPI/device tree.
>
> This is based on Goodix datasheets for GT911 and GT9271 and on Goodix
> driver gt9xx.c for Android (publicly available in Android kernel
> trees for various devices).
>
> For reset the driver needs to control the interrupt and
> reset gpio pins (configured through ACPI/device tree). For devices
> that do not have the gpio pins declared, the functionality depending
> on these pins will not be available, but the device can still be used
> with basic functionality.
>
I tested this patch on ARM tablet Wexler TAB7200 with GT911 touchscreen
controller. All works fine.
Tested-by: Aleksei Mamlin <mamlinav@...il.com>
>
> Signed-off-by: Octavian Purdila <octavian.purdila@...el.com>
> Signed-off-by: Irina Tirdea <irina.tirdea@...el.com>
> ---
> .../bindings/input/touchscreen/goodix.txt | 5 +
> drivers/input/touchscreen/goodix.c | 136 +++++++++++++++++++++
> 2 files changed, 141 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> index 8ba98ee..c0715f8 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> +++ b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> @@ -12,6 +12,8 @@ Required properties:
> - reg : I2C address of the chip. Should be 0x5d or 0x14
> - interrupt-parent : Interrupt controller to which the chip is connected
> - interrupts : Interrupt to which the chip is connected
> + - gpios : GPIOS the chip is connected to: first one is the
> + interrupt gpio and second one the reset gpio.
>
> Example:
>
> @@ -23,6 +25,9 @@ Example:
> reg = <0x5d>;
> interrupt-parent = <&gpio>;
> interrupts = <0 0>;
> +
> + gpios = <&gpio1 0 0>, /* INT */
> + <&gpio1 1 0>; /* RST */
> };
>
> /* ... */
> diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
> index 7be6eab..9c58583 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -17,6 +17,7 @@
> #include <linux/acpi.h>
> #include <linux/delay.h>
> #include <linux/dmi.h>
> +#include <linux/gpio.h>
> #include <linux/i2c.h>
> #include <linux/input.h>
> #include <linux/input/mt.h>
> @@ -37,6 +38,8 @@ struct goodix_ts_data {
> unsigned int int_trigger_type;
> bool rotated_screen;
> int cfg_len;
> + struct gpio_desc *gpiod_int;
> + struct gpio_desc *gpiod_rst;
> };
>
> #define GOODIX_MAX_HEIGHT 4096
> @@ -89,6 +92,30 @@ static const struct dmi_system_id rotated_screen[] = {
> {}
> };
>
> +/*
> + * ACPI table specifies gpio pins in this order: first rst pin and
> + * then interrupt pin.
> + */
> +static const struct dmi_system_id goodix_rst_pin_first[] = {
> +#if defined(CONFIG_DMI) && defined(CONFIG_X86)
> + {
> + .ident = "WinBook TW100",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "WinBook"),
> + DMI_MATCH(DMI_PRODUCT_NAME, "TW100")
> + }
> + },
> + {
> + .ident = "WinBook TW700",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "WinBook"),
> + DMI_MATCH(DMI_PRODUCT_NAME, "TW700")
> + },
> + },
> +#endif
> + {}
> +};
> +
> /**
> * goodix_i2c_read - read data from a register of the i2c slave device.
> *
> @@ -237,6 +264,102 @@ static irqreturn_t goodix_ts_irq_handler(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> +static int goodix_int_sync(struct goodix_ts_data *ts)
> +{
> + int error;
> +
> + error = gpiod_direction_output(ts->gpiod_int, 0);
> + if (error)
> + return error;
> + msleep(50); /* T5: 50ms */
> +
> + return gpiod_direction_input(ts->gpiod_int);
> +}
> +
> +/**
> + * goodix_reset - Reset device during power on
> + *
> + * @ts: goodix_ts_data pointer
> + */
> +static int goodix_reset(struct goodix_ts_data *ts)
> +{
> + int error;
> +
> + /* begin select I2C slave addr */
> + error = gpiod_direction_output(ts->gpiod_rst, 0);
> + if (error)
> + return error;
> + msleep(20); /* T2: > 10ms */
> + /* HIGH: 0x28/0x29, LOW: 0xBA/0xBB */
> + error = gpiod_direction_output(ts->gpiod_int, ts->client->addr == 0x14);
> + if (error)
> + return error;
> + usleep_range(100, 2000); /* T3: > 100us */
> + error = gpiod_direction_output(ts->gpiod_rst, 1);
> + if (error)
> + return error;
> + usleep_range(6000, 10000); /* T4: > 5ms */
> + /* end select I2C slave addr */
> + error = gpiod_direction_input(ts->gpiod_rst);
> + if (error)
> + return error;
> + return goodix_int_sync(ts);
> +}
> +
> +/**
> + * goodix_get_gpio_config - Get GPIO config from ACPI/DT
> + *
> + * @ts: goodix_ts_data pointer
> + */
> +static int goodix_get_gpio_config(struct goodix_ts_data *ts,
> + const struct i2c_device_id *i2c_id)
> +{
> + int error;
> + struct device *dev;
> + struct gpio_desc *gpiod;
> + /* Default gpio pin order: irq, rst */
> + int irq_idx = 0, rst_idx = 1;
> +
> + if (!ts->client)
> + return -EINVAL;
> + dev = &ts->client->dev;
> +
> + if (dmi_check_system(goodix_rst_pin_first)) {
> + dev_dbg(&ts->client->dev,
> + "Applying 'reverse gpio pin order' quirk\n");
> + rst_idx = 0;
> + irq_idx = 1;
> + }
> +
> + /* Get interrupt GPIO pin number */
> + gpiod = devm_gpiod_get_index(dev, NULL, irq_idx, GPIOD_IN);
> + if (IS_ERR(gpiod)) {
> + error = PTR_ERR(gpiod);
> + if (error != -EPROBE_DEFER)
> + dev_warn(dev, "Failed to get GPIO %d: %d\n",
> + irq_idx, error);
> + if (error == -ENOENT)
> + return 0;
> + return error;
> + }
> + ts->gpiod_int = gpiod;
> +
> + /* Get the reset line GPIO pin number */
> + gpiod = devm_gpiod_get_index(dev, NULL, rst_idx, GPIOD_IN);
> + if (IS_ERR(gpiod)) {
> + error = PTR_ERR(gpiod);
> + if (error != -EPROBE_DEFER)
> + dev_warn(dev, "Failed to get GPIO %d: %d\n",
> + rst_idx, error);
> + if (error == -ENOENT)
> + return 0;
> + return error;
> + }
> + ts->gpiod_rst = gpiod;
> +
> + return 0;
> +}
> +
> /**
> * goodix_read_config - Read the embedded configuration of the panel
> *
> @@ -405,6 +528,19 @@ static int goodix_ts_probe(struct i2c_client *client,
> ts->client = client;
> i2c_set_clientdata(client, ts);
>
> + error = goodix_get_gpio_config(ts, id);
> + if (error)
> + return error;
> +
> + if (ts->gpiod_int && ts->gpiod_rst) {
> + /* reset the controller */
> + error = goodix_reset(ts);
> + if (error) {
> + dev_err(&client->dev, "Controller reset failed.\n");
> + return error;
> + }
> + }
> +
> error = goodix_i2c_test(client);
> if (error) {
> dev_err(&client->dev, "I2C communication failure: %d\n", error);
> --
> 1.9.1
>
--
Thanks and regards,
Aleksei Mamlin
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