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wacom: add manual GPIO based reset code in wacom driver probe

pull/10/head
Steinar Bakkemo 2020-10-07 11:42:56 +02:00
parent 37af404c32
commit 6838f4357c
2 changed files with 43 additions and 1 deletions
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42
drivers/input/touchscreen/wacom_i2c.c
View File

@ -19,8 +19,11 @@
#include <linux/interrupt.h>
#include <linux/gpio.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <asm/unaligned.h>
#include <linux/kernel.h>
#include <linux/reset.h>
#include <linux/delay.h>
#define WACOM_CMD_QUERY0 0x04
#define WACOM_CMD_QUERY1 0x00
@ -78,6 +81,15 @@ static int wacom_query_device(struct i2c_client *client,
},
};
printk("[---- SBA ----] Asserting/deasserting WACOM reset ..\n");
struct reset_control *rstc = devm_reset_control_get_optional_exclusive(&client->dev, NULL);
if (IS_ERR(rstc)) {
printk("[---- SBA ----] Failed to get reset control while trying to reset WACOM device before init !\n");
}
else {
reset_control_reset(rstc);
}
printk("[---- SBA ----] Sending cmd1, cmd2 and data over I2C ..\n");
ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
if (ret < 0) {
@ -85,7 +97,7 @@ static int wacom_query_device(struct i2c_client *client,
return ret;
}
if (ret != ARRAY_SIZE(msgs)) {
printk("[---- SBA ----] i2c_transfer returned with unexpected return value %2\n", msgs);
printk("[---- SBA ----] i2c_transfer returned with unexpected return value %d\n", ret);
return -EIO;
}
@ -199,6 +211,34 @@ static int wacom_i2c_probe(struct i2c_client *client,
return -EIO;
}
printk("[---- SBA ----] Reading reset-gpio config if present..\n");
struct device_node *np = client->dev.of_node;
unsigned int flags;
unsigned int reset_gpio = of_get_named_gpio_flags(np, "reset-gpio", 0, &flags);
if (reset_gpio == -EPROBE_DEFER) {
printk("[---- SBA ----] of_get_named_gpio_flags returned EPROBE_DEFER, ignoring reset-gpio..\n");
} else if (!gpio_is_valid(reset_gpio)) {
printk("[---- SBA ----] reset-gpio found: %d\n", reset_gpio);
printk("[---- SBA ----] Invalid reset gpio: %d\n", reset_gpio);
}
printk("[---- SBA ----] Requesting gpio %d ..\n", reset_gpio);
unsigned int ret = devm_gpio_request_one(&client->dev, reset_gpio, flags, NULL);
if (ret < 0) {
printk("[---- SBA ----] Failed to request gpio %d: %d\n", reset_gpio, ret);
}
printk("[---- SBA ----] Setting requested GPIO as output ..\n");
gpio_direction_output(reset_gpio, 1);
printk("[---- SBA ----] Trying to pull reset GPIO low ..\n");
gpio_set_value(reset_gpio, 0);
printk("[---- SBA ----] Waiting 500 us..\n");
udelay(500);
printk("[---- SBA ----] Trying to pull reset GPIO high ..\n");
gpio_set_value(reset_gpio, 1);
printk("[---- SBA ----] Waiting 500 us..\n");
udelay(500);
printk("[---- SBA ----] Querying device ..\n");
error = wacom_query_device(client, &features);
if (error)

2
drivers/reset/gpio-reset.c
View File

@ -58,6 +58,7 @@ static int gpio_reset(struct reset_controller_dev *rcdev, unsigned long id)
static int gpio_reset_assert(struct reset_controller_dev *rcdev,
unsigned long id)
{
printk("[---- SBA ----] gpio_reset_assert (module %s)\n", rcdev->owner->name);
gpio_reset_set(rcdev, 1);
return 0;
@ -66,6 +67,7 @@ static int gpio_reset_assert(struct reset_controller_dev *rcdev,
static int gpio_reset_deassert(struct reset_controller_dev *rcdev,
unsigned long id)
{
printk("[---- SBA ----] gpio_reset_deassert (module %s)..\n", rcdev->owner->name);
gpio_reset_set(rcdev, 0);
return 0;