2021-10-04 19:28:51

by Marijn Suijten

Subject: [PATCH 02/10] backlight: qcom-wled: Use cpu_to_le16 macro to perform conversion

The kernel already provides appropriate primitives to perform endianness
conversion which should be used in favour of manual bit-wrangling.

Signed-off-by: Marijn Suijten <[email protected]>
Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
---
drivers/video/backlight/qcom-wled.c | 25 +++++++++++--------------
1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index 6af808af2328..9927ed98944a 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -231,14 +231,14 @@ struct wled {
static int wled3_set_brightness(struct wled *wled, u16 brightness)
{
int rc, i;
- u8 v[2];
+ u16 v;

- v[0] = brightness & 0xff;
- v[1] = (brightness >> 8) & 0xf;
+ v = cpu_to_le16(brightness & WLED3_SINK_REG_BRIGHT_MAX);

for (i = 0; i < wled->cfg.num_strings; ++i) {
rc = regmap_bulk_write(wled->regmap, wled->ctrl_addr +
- WLED3_SINK_REG_BRIGHT(i), v, 2);
+ WLED3_SINK_REG_BRIGHT(i),
+ &v, sizeof(v));
if (rc < 0)
return rc;
}
@@ -249,19 +249,18 @@ static int wled3_set_brightness(struct wled *wled, u16 brightness)
static int wled4_set_brightness(struct wled *wled, u16 brightness)
{
int rc, i;
- u16 low_limit = wled->max_brightness * 4 / 1000;
- u8 v[2];
+ u16 v, low_limit = wled->max_brightness * 4 / 1000;

/* WLED4's lower limit of operation is 0.4% */
if (brightness > 0 && brightness < low_limit)
brightness = low_limit;

- v[0] = brightness & 0xff;
- v[1] = (brightness >> 8) & 0xf;
+ v = cpu_to_le16(brightness & WLED3_SINK_REG_BRIGHT_MAX);

for (i = 0; i < wled->cfg.num_strings; ++i) {
rc = regmap_bulk_write(wled->regmap, wled->sink_addr +
- WLED4_SINK_REG_BRIGHT(i), v, 2);
+ WLED4_SINK_REG_BRIGHT(i),
+ &v, sizeof(v));
if (rc < 0)
return rc;
}
@@ -272,22 +271,20 @@ static int wled4_set_brightness(struct wled *wled, u16 brightness)
static int wled5_set_brightness(struct wled *wled, u16 brightness)
{
int rc, offset;
- u16 low_limit = wled->max_brightness * 1 / 1000;
- u8 v[2];
+ u16 v, low_limit = wled->max_brightness * 1 / 1000;

/* WLED5's lower limit is 0.1% */
if (brightness < low_limit)
brightness = low_limit;

- v[0] = brightness & 0xff;
- v[1] = (brightness >> 8) & 0x7f;
+ v = cpu_to_le16(brightness & WLED5_SINK_REG_BRIGHT_MAX_15B);

offset = (wled->cfg.mod_sel == MOD_A) ?
WLED5_SINK_REG_MOD_A_BRIGHTNESS_LSB :
WLED5_SINK_REG_MOD_B_BRIGHTNESS_LSB;

rc = regmap_bulk_write(wled->regmap, wled->sink_addr + offset,
- v, 2);
+ &v, sizeof(v));
return rc;
}

--
2.33.0

2021-10-05 09:08:57

by Daniel Thompson

Subject: Re: [PATCH 02/10] backlight: qcom-wled: Use cpu_to_le16 macro to perform conversion

On Mon, Oct 04, 2021 at 09:27:33PM +0200, Marijn Suijten wrote:
> The kernel already provides appropriate primitives to perform endianness
> conversion which should be used in favour of manual bit-wrangling.
>
> Signed-off-by: Marijn Suijten <[email protected]>
> Reviewed-by: AngeloGioacchino Del Regno <[email protected]>

Reviewed-by: Daniel Thompson <[email protected]>


> ---
> drivers/video/backlight/qcom-wled.c | 25 +++++++++++--------------
> 1 file changed, 11 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index 6af808af2328..9927ed98944a 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> @@ -231,14 +231,14 @@ struct wled {
> static int wled3_set_brightness(struct wled *wled, u16 brightness)
> {
> int rc, i;
> - u8 v[2];
> + u16 v;
>
> - v[0] = brightness & 0xff;
> - v[1] = (brightness >> 8) & 0xf;
> + v = cpu_to_le16(brightness & WLED3_SINK_REG_BRIGHT_MAX);
>
> for (i = 0; i < wled->cfg.num_strings; ++i) {
> rc = regmap_bulk_write(wled->regmap, wled->ctrl_addr +
> - WLED3_SINK_REG_BRIGHT(i), v, 2);
> + WLED3_SINK_REG_BRIGHT(i),
> + &v, sizeof(v));
> if (rc < 0)
> return rc;
> }
> @@ -249,19 +249,18 @@ static int wled3_set_brightness(struct wled *wled, u16 brightness)
> static int wled4_set_brightness(struct wled *wled, u16 brightness)
> {
> int rc, i;
> - u16 low_limit = wled->max_brightness * 4 / 1000;
> - u8 v[2];
> + u16 v, low_limit = wled->max_brightness * 4 / 1000;
>
> /* WLED4's lower limit of operation is 0.4% */
> if (brightness > 0 && brightness < low_limit)
> brightness = low_limit;
>
> - v[0] = brightness & 0xff;
> - v[1] = (brightness >> 8) & 0xf;
> + v = cpu_to_le16(brightness & WLED3_SINK_REG_BRIGHT_MAX);
>
> for (i = 0; i < wled->cfg.num_strings; ++i) {
> rc = regmap_bulk_write(wled->regmap, wled->sink_addr +
> - WLED4_SINK_REG_BRIGHT(i), v, 2);
> + WLED4_SINK_REG_BRIGHT(i),
> + &v, sizeof(v));
> if (rc < 0)
> return rc;
> }
> @@ -272,22 +271,20 @@ static int wled4_set_brightness(struct wled *wled, u16 brightness)
> static int wled5_set_brightness(struct wled *wled, u16 brightness)
> {
> int rc, offset;
> - u16 low_limit = wled->max_brightness * 1 / 1000;
> - u8 v[2];
> + u16 v, low_limit = wled->max_brightness * 1 / 1000;
>
> /* WLED5's lower limit is 0.1% */
> if (brightness < low_limit)
> brightness = low_limit;
>
> - v[0] = brightness & 0xff;
> - v[1] = (brightness >> 8) & 0x7f;
> + v = cpu_to_le16(brightness & WLED5_SINK_REG_BRIGHT_MAX_15B);
>
> offset = (wled->cfg.mod_sel == MOD_A) ?
> WLED5_SINK_REG_MOD_A_BRIGHTNESS_LSB :
> WLED5_SINK_REG_MOD_B_BRIGHTNESS_LSB;
>
> rc = regmap_bulk_write(wled->regmap, wled->sink_addr + offset,
> - v, 2);
> + &v, sizeof(v));
> return rc;
> }
>
> --
> 2.33.0
>