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Message-ID: <20250407095119.588920-4-mitltlatltl@gmail.com>
Date: Mon, 7 Apr 2025 17:51:18 +0800
From: Pengyu Luo <mitltlatltl@...il.com>
To: Jianhua Lu <lujianhua000@...il.com>,
Lee Jones <lee@...nel.org>,
Daniel Thompson <danielt@...nel.org>,
Jingoo Han <jingoohan1@...il.com>,
Pavel Machek <pavel@...nel.org>,
Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>,
Helge Deller <deller@....de>
Cc: dri-devel@...ts.freedesktop.org,
linux-leds@...r.kernel.org,
devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org,
linux-fbdev@...r.kernel.org,
Pengyu Luo <mitltlatltl@...il.com>
Subject: [PATCH 3/4] backlight: ktz8866: improve current sinks setting
I polled all registers when the module was loading, found that
current sinks have already been configured. Bootloader would set
when booting. So checking it before setting the all channels.
Signed-off-by: Pengyu Luo <mitltlatltl@...il.com>
---
drivers/video/backlight/ktz8866.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/drivers/video/backlight/ktz8866.c b/drivers/video/backlight/ktz8866.c
index 017ad80dd..b67ca136d 100644
--- a/drivers/video/backlight/ktz8866.c
+++ b/drivers/video/backlight/ktz8866.c
@@ -46,6 +46,8 @@
#define LCD_BIAS_EN 0x9F
#define PWM_HYST 0x5
+#define CURRENT_SINKS_MASK GENMASK(5, 0)
+
struct ktz8866_slave {
struct i2c_client *client;
struct regmap *regmap;
@@ -65,6 +67,12 @@ static const struct regmap_config ktz8866_regmap_config = {
.max_register = REG_MAX,
};
+static inline void ktz8866_read(struct ktz8866 *ktz, unsigned int reg,
+ unsigned int *val)
+{
+ regmap_read(ktz->regmap, reg, &val);
+}
+
static void ktz8866_write(struct ktz8866 *ktz, unsigned int reg,
unsigned int val)
{
@@ -112,11 +120,18 @@ static void ktz8866_init(struct ktz8866 *ktz)
{
unsigned int val = 0;
- if (!of_property_read_u32(ktz->client->dev.of_node, "current-num-sinks", &val))
+ if (!of_property_read_u32(ktz->client->dev.of_node, "current-num-sinks", &val)) {
ktz8866_write(ktz, BL_EN, BIT(val) - 1);
- else
- /* Enable all 6 current sinks if the number of current sinks isn't specified. */
- ktz8866_write(ktz, BL_EN, BIT(6) - 1);
+ } else {
+ /*
+ * Enable all 6 current sinks if the number of current
+ * sinks isn't specified and the bootloader didn't set
+ * the value.
+ */
+ ktz8866_read(ktz, BL_EN, &val);
+ if (!(val && CURRENT_SINKS_MASK))
+ ktz8866_write(ktz, BL_EN, CURRENT_SINKS_MASK);
+ }
if (!of_property_read_u32(ktz->client->dev.of_node, "kinetic,current-ramp-delay-ms", &val)) {
if (val <= 128)
--
2.49.0
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