[PATCH 1/2] dt-bindings: Add DT bindings for RaspberryPi 7" display ATTINY88-based regulator/backlight controller

[PATCH 1/2] dt-bindings: Add DT bindings for RaspberryPi 7" display ATTINY88-based regulator/backlight controller

[Marek Vasut]

Add DT bindings for RaspberryPi 7" display ATTINY88-based
regulator/backlight controller, this one is used in the
Raspberry Pi 7" touchscreen display unit.

Signed-off-by: Marek Vasut <marex@denx.de>
To: dri-devel@lists.freedesktop.org
Cc: Eric Anholt <eric@anholt.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: devicetree@vger.kernel.org
---
 ...ypi,7inch-touchscreen-panel-regulator.yaml | 44 +++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/regulator/raspberrypi,7inch-touchscreen-panel-regulator.yaml

diff --git a/Documentation/devicetree/bindings/regulator/raspberrypi,7inch-touchscreen-panel-regulator.yaml b/Documentation/devicetree/bindings/regulator/raspberrypi,7inch-touchscreen-panel-regulator.yaml
new file mode 100644
index 000000000000..0ae25d119b6f
--- /dev/null
+++ b/Documentation/devicetree/bindings/regulator/raspberrypi,7inch-touchscreen-panel-regulator.yaml
@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/raspberrypi,7inch-touchscreen-panel-regulator.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RaspberryPi 7" display ATTINY88-based regulator/backlight controller
+
+maintainers:
+  - Marek Vasut <marex@denx.de>
+
+description: |
+  The RaspberryPi 7" display has an ATTINY88-based regulator/backlight
+  controller on the PCB, which is used to turn the display unit on/off
+  and control the backlight.
+
+allOf:
+  - $ref: "regulator.yaml#"
+
+properties:
+  compatible:
+    const: raspberrypi,7inch-touchscreen-panel-regulator
+
+  reg:
+    maxItems: 1
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      regulator@45 {
+        compatible = "raspberrypi,7inch-touchscreen-panel-regulator";
+        reg = <0x45>;
+      };
+    };
+
+...
-- 
2.28.0

[PATCH 1/2] dt-bindings: Add DT bindings for RaspberryPi 7" display ATTINY88-based regulator/backlight controller

[Marek Vasut]

Add DT bindings for RaspberryPi 7" display ATTINY88-based
regulator/backlight controller, this one is used in the
Raspberry Pi 7" touchscreen display unit.

Signed-off-by: Marek Vasut <marex@denx.de>
To: dri-devel@lists.freedesktop.org
Cc: Eric Anholt <eric@anholt.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: devicetree@vger.kernel.org
---
 ...ypi,7inch-touchscreen-panel-regulator.yaml | 44 +++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/regulator/raspberrypi,7inch-touchscreen-panel-regulator.yaml

diff --git a/Documentation/devicetree/bindings/regulator/raspberrypi,7inch-touchscreen-panel-regulator.yaml b/Documentation/devicetree/bindings/regulator/raspberrypi,7inch-touchscreen-panel-regulator.yaml
new file mode 100644
index 000000000000..0ae25d119b6f
--- /dev/null
+++ b/Documentation/devicetree/bindings/regulator/raspberrypi,7inch-touchscreen-panel-regulator.yaml
@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/raspberrypi,7inch-touchscreen-panel-regulator.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RaspberryPi 7" display ATTINY88-based regulator/backlight controller
+
+maintainers:
+  - Marek Vasut <marex@denx.de>
+
+description: |
+  The RaspberryPi 7" display has an ATTINY88-based regulator/backlight
+  controller on the PCB, which is used to turn the display unit on/off
+  and control the backlight.
+
+allOf:
+  - $ref: "regulator.yaml#"
+
+properties:
+  compatible:
+    const: raspberrypi,7inch-touchscreen-panel-regulator
+
+  reg:
+    maxItems: 1
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      regulator@45 {
+        compatible = "raspberrypi,7inch-touchscreen-panel-regulator";
+        reg = <0x45>;
+      };
+    };
+
+...
-- 
2.28.0

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[PATCH 2/2] regulator: rpi-panel: Add regulator/backlight driver for RPi panel

[Marek Vasut]

This regulator/backlight driver handles the ATTINY88 present on the
RPi 7" touchscreen panel and exposes the power/backlight interfaces.

Signed-off-by: Marek Vasut <marex@denx.de>
To: dri-devel@lists.freedesktop.org
Cc: Eric Anholt <eric@anholt.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
---
 drivers/regulator/Kconfig                     |  10 +
 drivers/regulator/Makefile                    |   1 +
 .../regulator/rpi-panel-attiny-regulator.c    | 214 ++++++++++++++++++
 3 files changed, 225 insertions(+)
 create mode 100644 drivers/regulator/rpi-panel-attiny-regulator.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index de17ef7e18f0..439cc5226bae 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -864,6 +864,16 @@ config REGULATOR_QCOM_USB_VBUS
 	  Say M here if you want to include support for enabling the VBUS output
 	  as a module. The module will be named "qcom_usb_vbus_regulator".
 
+config REGULATOR_RASPBERRYPI_TOUCHSCREEN_ATTINY
+	tristate "Raspberry Pi 7-inch touchscreen panel ATTINY regulator"
+	depends on BACKLIGHT_CLASS_DEVICE
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  This driver supports ATTINY regulator on the Raspberry Pi 7-inch
+	  touchscreen unit. The regulator is used to enable power to the
+	  TC358762, display and to control backlight.
+
 config REGULATOR_RC5T583
 	tristate "RICOH RC5T583 Power regulators"
 	depends on MFD_RC5T583
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index d8d3ecf526a8..6e39ea87901e 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -107,6 +107,7 @@ obj-$(CONFIG_REGULATOR_TPS51632) += tps51632-regulator.o
 obj-$(CONFIG_REGULATOR_PBIAS) += pbias-regulator.o
 obj-$(CONFIG_REGULATOR_PCAP) += pcap-regulator.o
 obj-$(CONFIG_REGULATOR_PCF50633) += pcf50633-regulator.o
+obj-$(CONFIG_REGULATOR_RASPBERRYPI_TOUCHSCREEN_ATTINY)  += rpi-panel-attiny-regulator.o
 obj-$(CONFIG_REGULATOR_RC5T583)  += rc5t583-regulator.o
 obj-$(CONFIG_REGULATOR_RK808)   += rk808-regulator.o
 obj-$(CONFIG_REGULATOR_RN5T618) += rn5t618-regulator.o
diff --git a/drivers/regulator/rpi-panel-attiny-regulator.c b/drivers/regulator/rpi-panel-attiny-regulator.c
new file mode 100644
index 000000000000..ee46bfbf5eee
--- /dev/null
+++ b/drivers/regulator/rpi-panel-attiny-regulator.c
@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Marek Vasut <marex@denx.de>
+ *
+ * Based on rpi_touchscreen.c by Eric Anholt <eric@anholt.net>
+ */
+
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/slab.h>
+
+/* I2C registers of the Atmel microcontroller. */
+#define REG_ID		0x80
+#define REG_PORTA	0x81
+#define REG_PORTA_HF	BIT(2)
+#define REG_PORTA_VF	BIT(3)
+#define REG_PORTB	0x82
+#define REG_POWERON	0x85
+#define REG_PWM		0x86
+
+static const struct regmap_config attiny_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = REG_PWM,
+	.cache_type = REGCACHE_NONE,
+};
+
+static int attiny_lcd_power_enable(struct regulator_dev *rdev)
+{
+	unsigned int data;
+
+	regmap_write(rdev->regmap, REG_POWERON, 1);
+	/* Wait for nPWRDWN to go low to indicate poweron is done. */
+	regmap_read_poll_timeout(rdev->regmap, REG_PORTB, data,
+					data & BIT(0), 10, 1000000);
+
+	/* Default to the same orientation as the closed source
+	 * firmware used for the panel.  Runtime rotation
+	 * configuration will be supported using VC4's plane
+	 * orientation bits.
+	 */
+	regmap_write(rdev->regmap, REG_PORTA, BIT(2));
+
+	return 0;
+}
+
+static int attiny_lcd_power_disable(struct regulator_dev *rdev)
+{
+	regmap_write(rdev->regmap, REG_PWM, 0);
+	regmap_write(rdev->regmap, REG_POWERON, 0);
+	udelay(1);
+	return 0;
+}
+
+static int attiny_lcd_power_is_enabled(struct regulator_dev *rdev)
+{
+	unsigned int data;
+	int ret;
+
+	ret = regmap_read(rdev->regmap, REG_POWERON, &data);
+	if (ret < 0)
+		return ret;
+
+	if (!(data & BIT(0)))
+		return 0;
+
+	ret = regmap_read(rdev->regmap, REG_PORTB, &data);
+	if (ret < 0)
+		return ret;
+
+	return data & BIT(0);
+}
+
+static const struct regulator_init_data attiny_regulator_default = {
+	.constraints = {
+		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
+	},
+};
+
+static const struct regulator_ops attiny_regulator_ops = {
+	.enable = attiny_lcd_power_enable,
+	.disable = attiny_lcd_power_disable,
+	.is_enabled = attiny_lcd_power_is_enabled,
+};
+
+static const struct regulator_desc attiny_regulator = {
+	.name	= "tc358762-power",
+	.ops	= &attiny_regulator_ops,
+	.type	= REGULATOR_VOLTAGE,
+	.owner	= THIS_MODULE,
+};
+
+static int attiny_update_status(struct backlight_device *bl)
+{
+	struct regmap *regmap = bl_get_data(bl);
+	int brightness = bl->props.brightness;
+
+	if (bl->props.power != FB_BLANK_UNBLANK ||
+	    bl->props.fb_blank != FB_BLANK_UNBLANK)
+		brightness = 0;
+
+	return regmap_write(regmap, REG_PWM, brightness);
+}
+
+static int attiny_get_brightness(struct backlight_device *bl)
+{
+	struct regmap *regmap = bl_get_data(bl);
+	int ret, brightness;
+
+	ret = regmap_read(regmap, REG_PWM, &brightness);
+	if (ret)
+		return ret;
+
+	return brightness;
+}
+
+static const struct backlight_ops attiny_bl = {
+	.update_status	= attiny_update_status,
+	.get_brightness	= attiny_get_brightness,
+};
+
+/*
+ * I2C driver interface functions
+ */
+static int attiny_i2c_probe(struct i2c_client *i2c,
+		const struct i2c_device_id *id)
+{
+	struct backlight_properties props = { };
+	struct regulator_config config = { };
+	struct backlight_device *bl;
+	struct regulator_dev *rdev;
+	struct regmap *regmap;
+	unsigned int data;
+	int ret;
+
+	regmap = devm_regmap_init_i2c(i2c, &attiny_regmap_config);
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
+		dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
+			ret);
+		return ret;
+	}
+
+	ret = regmap_read(regmap, REG_ID, &data);
+	if (ret < 0) {
+		dev_err(&i2c->dev, "Failed to read REG_ID reg: %d\n", ret);
+		return ret;
+	}
+
+	switch (data) {
+	case 0xde: /* ver 1 */
+	case 0xc3: /* ver 2 */
+		break;
+	default:
+		dev_err(&i2c->dev, "Unknown Atmel firmware revision: 0x%02x\n", data);
+		return -ENODEV;
+	}
+
+	regmap_write(regmap, REG_POWERON, 0);
+	mdelay(1);
+
+	config.dev = &i2c->dev;
+	config.regmap = regmap;
+	config.of_node = i2c->dev.of_node;
+	config.init_data = &attiny_regulator_default;
+
+	rdev = devm_regulator_register(&i2c->dev, &attiny_regulator, &config);
+	if (IS_ERR(rdev)) {
+		dev_err(&i2c->dev, "Failed to register ATTINY regulator\n");
+		return PTR_ERR(rdev);
+	}
+
+	props.type = BACKLIGHT_RAW;
+	props.max_brightness = 0xff;
+	bl = devm_backlight_device_register(&i2c->dev,
+					    "7inch-touchscreen-panel-bl",
+					    &i2c->dev, regmap, &attiny_bl,
+					    &props);
+	if (IS_ERR(bl))
+		return PTR_ERR(bl);
+
+	bl->props.brightness = 0xff;
+
+	return 0;
+}
+
+static const struct of_device_id attiny_dt_ids[] = {
+	{ .compatible = "raspberrypi,7inch-touchscreen-panel-regulator" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, attiny_dt_ids);
+
+static struct i2c_driver attiny_regulator_driver = {
+	.driver = {
+		.name = "rpi_touchscreen_attiny",
+		.of_match_table = of_match_ptr(attiny_dt_ids),
+	},
+	.probe = attiny_i2c_probe,
+};
+
+module_i2c_driver(attiny_regulator_driver);
+
+MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
+MODULE_DESCRIPTION("Regulator device driver for Raspberry Pi 7-inch touchscreen");
+MODULE_LICENSE("GPL v2");
-- 
2.28.0

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Re: [PATCH 1/2] dt-bindings: Add DT bindings for RaspberryPi 7" display ATTINY88-based regulator/backlight controller

[Mark Brown]

On Sun, 9 Aug 2020 12:59:37 +0200, Marek Vasut wrote:
> Add DT bindings for RaspberryPi 7" display ATTINY88-based
> regulator/backlight controller, this one is used in the
> Raspberry Pi 7" touchscreen display unit.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-next

Thanks!

[1/2] regulator: Add DT bindings for RaspberryPi 7" display ATTINY88-based regulator/backlight controller
      commit: 9c535960891470eaec5664eed2a56dbb2b6a205b
[2/2] regulator: rpi-panel: Add regulator/backlight driver for RPi panel
      commit: 38573472278da49e2ab588062d88bc2f0c11a325

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

Re: [PATCH 1/2] dt-bindings: Add DT bindings for RaspberryPi 7" display ATTINY88-based regulator/backlight controller

[Mark Brown]

On Sun, 9 Aug 2020 12:59:37 +0200, Marek Vasut wrote:
> Add DT bindings for RaspberryPi 7" display ATTINY88-based
> regulator/backlight controller, this one is used in the
> Raspberry Pi 7" touchscreen display unit.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-next

Thanks!

[1/2] regulator: Add DT bindings for RaspberryPi 7" display ATTINY88-based regulator/backlight controller
      commit: 9c535960891470eaec5664eed2a56dbb2b6a205b
[2/2] regulator: rpi-panel: Add regulator/backlight driver for RPi panel
      commit: 38573472278da49e2ab588062d88bc2f0c11a325

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark
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