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From:   Emil Renner Berthing <emil.renner.berthing@canonical.com>
To:     linux-kernel@vger.kernel.org
Cc:     Pavel Machek <pavel@ucw.cz>, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Vincent Pelletier <plr.vincent@gmail.com>,
        Bin Meng <bin.meng@windriver.com>,
        Aurelien Jarno <aurelien@aurel32.net>,
        Ron Economos <w6rz@comcast.net>,
        Qiu Wenbo <qiuwenbo@kylinos.com.cn>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Stephen L Arnold <nerdboy@gentoo.org>,
        Jianlong Huang <jianlong.huang@starfivetech.com>,
        Mark Kettenis <kettenis@openbsd.org>,
        Sven Schwermer <sven.schwermer@disruptive-technologies.com>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        David Abdurachmanov <davidlt@rivosinc.com>,
        linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
        linux-riscv@lists.infradead.org
Subject: [PATCH v1 3/4] leds: pwm-multicolor: Support active-low LEDs
Date:   Tue,  5 Jul 2022 23:01:42 +0200
Message-Id: <20220705210143.315151-4-emil.renner.berthing@canonical.com>
In-Reply-To: <20220705210143.315151-1-emil.renner.berthing@canonical.com>
References: <20220705210143.315151-1-emil.renner.berthing@canonical.com>
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Add support for LEDs wired up to light when the PWM output is low, just
like the regular PWM LEDs.

Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
---
 drivers/leds/rgb/leds-pwm-multicolor.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/leds/rgb/leds-pwm-multicolor.c b/drivers/leds/rgb/leds-pwm-multicolor.c
index eb67b89d28e9..da9d2218ae18 100644
--- a/drivers/leds/rgb/leds-pwm-multicolor.c
+++ b/drivers/leds/rgb/leds-pwm-multicolor.c
@@ -19,6 +19,7 @@
 struct pwm_led {
 	struct pwm_device *pwm;
 	struct pwm_state state;
+	bool active_low;
 };
 
 struct pwm_mc_led {
@@ -45,6 +46,9 @@ static int led_pwm_mc_set(struct led_classdev *cdev,
 		duty *= mc_cdev->subled_info[i].brightness;
 		do_div(duty, cdev->max_brightness);
 
+		if (priv->leds[i].active_low)
+			duty = priv->leds[i].state.period - duty;
+
 		priv->leds[i].state.duty_cycle = duty;
 		priv->leds[i].state.enabled = duty > 0;
 		ret = pwm_apply_state(priv->leds[i].pwm,
@@ -76,6 +80,7 @@ static int iterate_subleds(struct device *dev, struct pwm_mc_led *priv,
 			goto release_fwnode;
 		}
 		pwm_init_state(pwmled->pwm, &pwmled->state);
+		pwmled->active_low = fwnode_property_read_bool(fwnode, "active-low");
 
 		ret = fwnode_property_read_u32(fwnode, "color", &color);
 		if (ret) {
-- 
2.37.0