From: Benjamin Bara <benjamin.bara@xxxxxxxxxxx> This enables the usage of "can_sleep" GPIO chips as "pin up" GPIO. This might be the case if the GPIO chip is an expander behind i2c. Signed-off-by: Benjamin Bara <benjamin.bara@xxxxxxxxxxx> Signed-off-by: Richard Leitner <richard.leitner@xxxxxxxxxxx> --- drivers/input/touchscreen/tsc2007.h | 1 + drivers/input/touchscreen/tsc2007_core.c | 38 ++++++++++++++++++++---- 2 files changed, 34 insertions(+), 5 deletions(-) diff --git a/drivers/input/touchscreen/tsc2007.h b/drivers/input/touchscreen/tsc2007.h index 69b08dd6c8df..29bd1ff22c72 100644 --- a/drivers/input/touchscreen/tsc2007.h +++ b/drivers/input/touchscreen/tsc2007.h @@ -78,6 +78,7 @@ struct tsc2007 { bool stopped; int (*get_pendown_state)(struct device *); + int (*get_pendown_state_cansleep)(struct device *); void (*clear_penirq)(void); struct mutex mlock; diff --git a/drivers/input/touchscreen/tsc2007_core.c b/drivers/input/touchscreen/tsc2007_core.c index 3e871d182c40..0ad4c3c41297 100644 --- a/drivers/input/touchscreen/tsc2007_core.c +++ b/drivers/input/touchscreen/tsc2007_core.c @@ -20,6 +20,7 @@ #include <linux/module.h> #include <linux/slab.h> #include <linux/gpio/consumer.h> +#include <linux/gpio/driver.h> #include <linux/input.h> #include <linux/interrupt.h> #include <linux/i2c.h> @@ -108,6 +109,14 @@ bool tsc2007_is_pen_down(struct tsc2007 *ts) return ts->get_pendown_state(&ts->client->dev); } +bool tsc2007_is_pen_down_cansleep(struct tsc2007 *ts) +{ + if (!ts->get_pendown_state_cansleep) + return true; + + return ts->get_pendown_state_cansleep(&ts->client->dev); +} + static irqreturn_t tsc2007_soft_irq(int irq, void *handle) { struct tsc2007 *ts = handle; @@ -115,7 +124,7 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle) struct ts_event tc; u32 rt; - while (!ts->stopped && tsc2007_is_pen_down(ts)) { + while (!ts->stopped && tsc2007_is_pen_down_cansleep(ts)) { /* pen is down, continue with the measurement */ @@ -125,7 +134,7 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle) rt = tsc2007_calculate_resistance(ts, &tc); - if (!rt && !ts->get_pendown_state) { + if (!rt && !ts->get_pendown_state_cansleep) { /* * If pressure reported is 0 and we don't have * callback to check pendown state, we have to @@ -229,6 +238,14 @@ static int tsc2007_get_pendown_state_gpio(struct device *dev) return gpiod_get_value(ts->gpiod); } +static int tsc2007_get_pendown_state_gpio_cansleep(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct tsc2007 *ts = i2c_get_clientdata(client); + + return gpiod_get_value_cansleep(ts->gpiod); +} + static int tsc2007_probe_properties(struct device *dev, struct tsc2007 *ts) { u32 val32; @@ -264,10 +281,21 @@ static int tsc2007_probe_properties(struct device *dev, struct tsc2007 *ts) if (IS_ERR(ts->gpiod)) return PTR_ERR(ts->gpiod); - if (ts->gpiod) - ts->get_pendown_state = tsc2007_get_pendown_state_gpio; - else + if (ts->gpiod) { + /* to support detection during the hard IRQ, the GPIO chip is required to not sleep. + * this might be the case if the GPIO is e.g. behind an i2c-based GPIO expander. + * it is fine to sleep later in the soft IRQ, as it is threaded. + */ + ts->get_pendown_state_cansleep = tsc2007_get_pendown_state_gpio_cansleep; + if (gpiod_to_chip(ts->gpiod) && !gpiod_to_chip(ts->gpiod)->can_sleep) { + ts->get_pendown_state = tsc2007_get_pendown_state_gpio; + } else { + dev_dbg(dev, "Pen down GPIO chip can sleep\n"); + } + + } else { dev_warn(dev, "Pen down GPIO is not specified in properties\n"); + } return 0; } -- 2.34.1