[PATCH v2] Input: tsc2007 - enable GPIO chips that can sleep

Benjamin Bara
2022-07-15T07:46:00Z

From: Benjamin Bara <benjamin.bara@skidata.com>

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@skidata.com>
Signed-off-by: Richard Leitner <richard.leitner@skidata.com>
---
drivers/input/touchscreen/tsc2007.h | 1 +
drivers/input/touchscreen/tsc2007_core.c | 34 ++++++++++++++++++++----
2 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/drivers/input/touchscreen/tsc2007.h b/drivers/input/touchscreen/tsc2007.h
index 69b08dd6c8df..cdd90d727160 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 *dev);
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..eba35ee1e28c 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);
}

+static 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 +281,17 @@ 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) {
+ ts->get_pendown_state_cansleep = tsc2007_get_pendown_state_gpio_cansleep;
+
+ /* pendown pin is read during hard irq -> gpio chip is not allowed to sleep */
+ 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