[PATCH v2] Input: omap4-keypad: react on keypresses if device is runtime-suspended

From: Andreas Kemnade
Date: Mon Dec 11 2023 - 17:18:32 EST


According to SWPU235AB, table 26-6, fclk is required to generate events
at least on OMAP4460, so keep fclk enabled all the time the device
is opened.

Suggested-by: Tony Lindgren <tony@xxxxxxxxxxx>
Signed-off-by: Andreas Kemnade <andreas@xxxxxxxxxxxx>
Reviewed-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
Changes in v2:
- error check for clk_prepare_enable() although it should never
be reached without that clock being enabled, but lets be
careful.
Changes since RFC:
- add R-by:
drivers/input/keyboard/omap4-keypad.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/input/keyboard/omap4-keypad.c b/drivers/input/keyboard/omap4-keypad.c
index d3f8688fdd9c3..040b340995d89 100644
--- a/drivers/input/keyboard/omap4-keypad.c
+++ b/drivers/input/keyboard/omap4-keypad.c
@@ -11,6 +11,7 @@
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
+#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/of.h>
@@ -83,6 +84,7 @@ struct omap4_keypad {
bool no_autorepeat;
u64 keys;
unsigned short *keymap;
+ struct clk *fck;
};

static int kbd_readl(struct omap4_keypad *keypad_data, u32 offset)
@@ -209,6 +211,10 @@ static int omap4_keypad_open(struct input_dev *input)
if (error)
return error;

+ error = clk_prepare_enable(keypad_data->fck);
+ if (error)
+ goto out;
+
disable_irq(keypad_data->irq);

kbd_writel(keypad_data, OMAP4_KBD_CTRL,
@@ -226,10 +232,11 @@ static int omap4_keypad_open(struct input_dev *input)

enable_irq(keypad_data->irq);

+out:
pm_runtime_mark_last_busy(dev);
pm_runtime_put_autosuspend(dev);

- return 0;
+ return error;
}

static void omap4_keypad_stop(struct omap4_keypad *keypad_data)
@@ -258,6 +265,7 @@ static void omap4_keypad_close(struct input_dev *input)
disable_irq(keypad_data->irq);
omap4_keypad_stop(keypad_data);
enable_irq(keypad_data->irq);
+ clk_disable_unprepare(keypad_data->fck);

pm_runtime_mark_last_busy(dev);
pm_runtime_put_autosuspend(dev);
@@ -356,6 +364,11 @@ static int omap4_keypad_probe(struct platform_device *pdev)
}

keypad_data->irq = irq;
+ keypad_data->fck = devm_clk_get(&pdev->dev, "fck");
+ if (IS_ERR(keypad_data->fck))
+ return dev_err_probe(&pdev->dev, PTR_ERR(keypad_data->fck),
+ "unable to get fck");
+
mutex_init(&keypad_data->lock);
platform_set_drvdata(pdev, keypad_data);

--
2.39.2