Merge tag 'backlight-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

Pull backlight updates from Lee Jones:
 "New Drivers:
   - Add support for Kinetic KTD2801 Backlight

  Fix-ups:
   - Fix include lists; alphabetise, remove unused, explicitly add used
   - Device Tree binding adaptions/conversions/creation
   - Use dev_err_probe() to clean-up error paths
   - Use/convert to new/better APIs/helpers/MACROs instead of hand-rolling implementations

  Bug Fixes:
   - Fix changes of NULL pointer dereference
   - Remedy a bunch of logic errors
   - Initialise (zero) Backlight properties data structures"

* tag 'backlight-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight: (32 commits)
  backlight: pandora_bl: Drop unneeded ENOMEM error message
  backlight: lm3630a_bl: Simplify probe return on gpio request error
  backlight: lm3630a_bl: Handle deferred probe
  backlight: as3711_bl: Handle deferred probe
  backlight: bd6107: Handle deferred probe
  backlight: l4f00242t03: Simplify with dev_err_probe()
  backlight: gpio: Simplify with dev_err_probe()
  backlight: lp8788: Fully initialize backlight_properties during probe
  backlight: lm3639: Fully initialize backlight_properties during probe
  backlight: da9052: Fully initialize backlight_properties during probe
  backlight: lm3630a: Use backlight_get_brightness helper in update_status
  backlight: lm3630a: Don't set bl->props.brightness in get_brightness
  backlight: lm3630a: Initialize backlight_properties on init
  backlight: mp3309c: Fully initialize backlight_properties during probe
  backlight: mp3309c: Utilise temporary variable for struct device
  backlight: mp3309c: Use dev_err_probe() instead of dev_err()
  backlight: mp3309c: Make use of device properties
  dt-bindings: backlight: qcom-wled: Fix bouncing email addresses
  backlight: hx8357: Utilise temporary variable for struct device
  backlight: hx8357: Make use of dev_err_probe()
  ...

1 files changed, 72 insertions, 0 deletions

diff --git a/drivers/leds/leds-expresswire.c b/drivers/leds/leds-expresswire.c
new file mode 100644
index 000000000000..e4937a8e0f44
--- /dev/null
+++ b/drivers/leds/leds-expresswire.c
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Shared library for Kinetic's ExpressWire protocol.
+ * This protocol works by pulsing the ExpressWire IC's control GPIO.
+ * ktd2692 and ktd2801 are known to use this protocol.
+ */
+
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/gpio/consumer.h>
+#include <linux/types.h>
+
+#include <linux/leds-expresswire.h>
+
+void expresswire_power_off(struct expresswire_common_props *props)
+{
+	gpiod_set_value_cansleep(props->ctrl_gpio, 0);
+	usleep_range(props->timing.poweroff_us, props->timing.poweroff_us * 2);
+}
+EXPORT_SYMBOL_NS_GPL(expresswire_power_off, EXPRESSWIRE);
+
+void expresswire_enable(struct expresswire_common_props *props)
+{
+	gpiod_set_value(props->ctrl_gpio, 1);
+	udelay(props->timing.detect_delay_us);
+	gpiod_set_value(props->ctrl_gpio, 0);
+	udelay(props->timing.detect_us);
+	gpiod_set_value(props->ctrl_gpio, 1);
+}
+EXPORT_SYMBOL_NS_GPL(expresswire_enable, EXPRESSWIRE);
+
+void expresswire_start(struct expresswire_common_props *props)
+{
+	gpiod_set_value(props->ctrl_gpio, 1);
+	udelay(props->timing.data_start_us);
+}
+EXPORT_SYMBOL_NS_GPL(expresswire_start, EXPRESSWIRE);
+
+void expresswire_end(struct expresswire_common_props *props)
+{
+	gpiod_set_value(props->ctrl_gpio, 0);
+	udelay(props->timing.end_of_data_low_us);
+	gpiod_set_value(props->ctrl_gpio, 1);
+	udelay(props->timing.end_of_data_high_us);
+}
+EXPORT_SYMBOL_NS_GPL(expresswire_end, EXPRESSWIRE);
+
+void expresswire_set_bit(struct expresswire_common_props *props, bool bit)
+{
+	if (bit) {
+		gpiod_set_value(props->ctrl_gpio, 0);
+		udelay(props->timing.short_bitset_us);
+		gpiod_set_value(props->ctrl_gpio, 1);
+		udelay(props->timing.long_bitset_us);
+	} else {
+		gpiod_set_value(props->ctrl_gpio, 0);
+		udelay(props->timing.long_bitset_us);
+		gpiod_set_value(props->ctrl_gpio, 1);
+		udelay(props->timing.short_bitset_us);
+	}
+}
+EXPORT_SYMBOL_NS_GPL(expresswire_set_bit, EXPRESSWIRE);
+
+void expresswire_write_u8(struct expresswire_common_props *props, u8 val)
+{
+	expresswire_start(props);
+	for (int i = 7; i >= 0; i--)
+		expresswire_set_bit(props, val & BIT(i));
+	expresswire_end(props);
+}
+EXPORT_SYMBOL_NS_GPL(expresswire_write_u8, EXPRESSWIRE);