[PATCH 5/9] input: goodix: reset device at init

Irina Tirdea
2015-05-28T12:48:43Z

After power on, it is recommended that the driver resets the device.
For reset the driver needs to control the interrupt and
reset gpio pins (configured through ACPI/device tree).

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
---
.../bindings/input/touchscreen/goodix.txt | 5 ++
drivers/input/touchscreen/goodix.c | 99 ++++++++++++++++++++++
2 files changed, 104 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
index 8ba98ee..7137881 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
+ - irq-gpio : GPIO pin used for IRQ
+ - reset-gpio : GPIO pin used for reset

Example:

@@ -23,6 +25,9 @@ Example:
reg = <0x5d>;
interrupt-parent = <&gpio>;
interrupts = <0 0>;
+
+ irq-gpio = <&gpio1 0 0>;
+ reset-gpio = <&gpio1 1 0>;
};

/* ... */
diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index 9e7d215..4405c55 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -26,6 +26,7 @@
#include <linux/acpi.h>
#include <linux/of.h>
#include <asm/unaligned.h>
+#include <linux/gpio.h>

struct goodix_ts_data {
struct i2c_client *client;
@@ -34,8 +35,12 @@ struct goodix_ts_data {
int abs_y_max;
unsigned int max_touch_num;
unsigned int int_trigger_type;
+ struct gpio_desc *gpiod_int;
+ struct gpio_desc *gpiod_rst;
};

+#define GOODIX_GPIO_INT_NAME "irq"
+#define GOODIX_GPIO_RST_NAME "reset"
#define GOODIX_MAX_HEIGHT 4096
#define GOODIX_MAX_WIDTH 4096
#define GOODIX_INT_TRIGGER 1
@@ -187,6 +192,89 @@ 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 ret;
+
+ ret = gpiod_direction_output(ts->gpiod_int, 0);
+ if (ret)
+ return ret;
+
+ 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 ret;
+
+ /* begin select I2C slave addr */
+ ret = gpiod_direction_output(ts->gpiod_rst, 0);
+ if (ret)
+ return ret;
+ msleep(20); /* T2: > 10ms */
+ /* HIGH: 0x28/0x29, LOW: 0xBA/0xBB */
+ ret = gpiod_direction_output(ts->gpiod_int, ts->client->addr == 0x14);
+ if (ret)
+ return ret;
+ usleep_range(100, 2000); /* T3: > 100us */
+ ret = gpiod_direction_output(ts->gpiod_rst, 1);
+ if (ret)
+ return ret;
+ usleep_range(6000, 10000); /* T4: > 5ms */
+ /* end select I2C slave addr */
+ ret = gpiod_direction_input(ts->gpiod_rst);
+ if (ret)
+ return ret;
+ ret = goodix_int_sync(ts);
+ if (ret)
+ return ret;
+ msleep(50); /* T5: 50ms */
+ return 0;
+}
+
+/**
+ * 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)
+{
+ struct device *dev;
+ struct gpio_desc *gpiod;
+ int ret;
+
+ if (!ts->client)
+ return -EINVAL;
+ dev = &ts->client->dev;
+
+ /* Get interrupt GPIO pin number */
+ gpiod = devm_gpiod_get(dev, GOODIX_GPIO_INT_NAME, GPIOD_IN);
+ if (IS_ERR(gpiod)) {
+ ret = PTR_ERR(gpiod);
+ dev_err(dev, "Failed to get %s GPIO: %d\n",
+ GOODIX_GPIO_INT_NAME, ret);
+ return ret;
+ }
+ ts->gpiod_int = gpiod;
+
+ /* Get the reset line GPIO pin number */
+ gpiod = devm_gpiod_get(dev, GOODIX_GPIO_RST_NAME, GPIOD_IN);
+ if (IS_ERR(gpiod)) {
+ ret = PTR_ERR(gpiod);
+ dev_err(dev, "Failed to get %s GPIO: %d\n",
+ GOODIX_GPIO_RST_NAME, ret);
+ return ret;
+ }
+ ts->gpiod_rst = gpiod;
+
+ return 0;
+}
+
/**
* goodix_read_config - Read the embedded configuration of the panel
*
@@ -366,6 +454,17 @@ static int goodix_ts_probe(struct i2c_client *client,
return error;
}

+ error = goodix_get_gpio_config(ts);
+ if (error)
+ return error;
+
+ /* reset the controller */
+ error = goodix_reset(ts);
+ if (error) {
+ dev_err(&client->dev, "Controller reset failed.\n");
+ return error;
+ }
+
goodix_read_config(ts);

error = goodix_request_input_dev(ts, version_info, id_info);
--
1.9.1