linux-kernel - [PATCH v5 3/3] bus: ts-nbus: use bitmap_set

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Message-Id: <20250613-gpio-set-array-helper-v5-3-273fab50cc8e@baylibre.com>
Date: Fri, 13 Jun 2025 13:55:30 -0500
From: David Lechner <dlechner@...libre.com>
To: Arnd Bergmann <arnd@...db.de>, linux-arm-kernel@...ts.infradead.org
Cc: Linus Walleij <linus.walleij@...aro.org>, 
 Bartosz Golaszewski <brgl@...ev.pl>, linux-gpio@...r.kernel.org, 
 linux-kernel@...r.kernel.org, Andy Shevchenko <andy.shevchenko@...il.com>, 
 David Lechner <dlechner@...libre.com>
Subject: [PATCH v5 3/3] bus: ts-nbus: use bitmap_set_value8()

Use bitmap_set_value8() instead of accessing the bitmap directly.

Accessing the bitmap directly is not considered good practice. We now
have a helper function that can be used instead, so let's use it.

The bitmap has to be zero-initialized now to avoid a compiler warning
since bitmap_set_value8() does read/modify/write rather than just the
write that this is replacing. In ts_nbus_reset_bus(), this zero-
initialization is enough and we don't need to replace the array
access with bitmap_clear().

Suggested-by: Andy Shevchenko <andy.shevchenko@...il.com>
Signed-off-by: David Lechner <dlechner@...libre.com>
---
v5 changes:
- Fix undeclared variable in ts_nbus_reset_bus()
v4 changes:
- Fix typo s/get/set/ in commit message
- Zero-initialize the bitmap to avoid compiler warning
---
 drivers/bus/ts-nbus.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/bus/ts-nbus.c b/drivers/bus/ts-nbus.c
index b4c9308caf0647a3261071d9527fffce77784af2..371fa83ad0db424ea48cd7c23e3070f56162d7ad 100644
--- a/drivers/bus/ts-nbus.c
+++ b/drivers/bus/ts-nbus.c
@@ -10,6 +10,7 @@
  * TS-4600 SoM.
  */
 
+#include <linux/bitmap.h>
 #include <linux/bitops.h>
 #include <linux/gpio/consumer.h>
 #include <linux/kernel.h>
@@ -105,9 +106,7 @@ static void ts_nbus_set_direction(struct ts_nbus *ts_nbus, int direction)
  */
 static void ts_nbus_reset_bus(struct ts_nbus *ts_nbus)
 {
-	DECLARE_BITMAP(values, 8);
-
-	values[0] = 0;
+	DECLARE_BITMAP(values, 8) = { };
 
 	gpiod_multi_set_value_cansleep(ts_nbus->data, values);
 	gpiod_set_value_cansleep(ts_nbus->csn, 0);
@@ -149,9 +148,9 @@ static int ts_nbus_read_byte(struct ts_nbus *ts_nbus, u8 *val)
  */
 static void ts_nbus_write_byte(struct ts_nbus *ts_nbus, u8 byte)
 {
-	DECLARE_BITMAP(values, 8);
+	DECLARE_BITMAP(values, 8) = { };
 
-	values[0] = byte;
+	bitmap_set_value8(values, byte, 8);
 
 	gpiod_multi_set_value_cansleep(ts_nbus->data, values);
 }

-- 
2.43.0