misc: Add Lontium LT7911D FB notifier driver

Change-Id: I9c0dcfed229267fe65d2923ddc4847642447e4b5
Signed-off-by: Wyon Bi <bivvy.bi@rock-chips.com>

drivers/misc/Kconfig

@@ -13,6 +13,13 @@ config RK803
 
 source "drivers/misc/rockchip/Kconfig"
 
+config LT7911D_FB_NOTIFIER
+	tristate "Lontium LT7911D FB Notifier"
+	depends on FB
+	help
+	   Enable this configuration option to enable the FB notifier driver
+	   for Lontium LT7911D.
+
 config SENSORS_LIS3LV02D
 	tristate
 	depends on INPUT

drivers/misc/Makefile

@@ -5,6 +5,7 @@
 
 obj-$(CONFIG_RK803)		+= rk803.o
 obj-y				+= rockchip/
+obj-$(CONFIG_LT7911D_FB_NOTIFIER) += lt7911d-fb-notifier.o
 obj-$(CONFIG_IBM_ASM)		+= ibmasm/
 obj-$(CONFIG_IBMVMC)		+= ibmvmc.o
 obj-$(CONFIG_AD525X_DPOT)	+= ad525x_dpot.o

drivers/misc/lt7911d-fb-notifier.c

@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2023 Rockchip Electronics Co. Ltd.
+ */
+
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/notifier.h>
+#include <linux/fb.h>
+
+struct lt7911d {
+	struct device *dev;
+	struct gpio_descs *gpios;
+	struct notifier_block fb_notif;
+	int fb_blank;
+};
+
+static int lt7911d_fb_notifier_callback(struct notifier_block *self,
+					unsigned long event, void *data)
+{
+	struct lt7911d *lt7911d = container_of(self, struct lt7911d, fb_notif);
+	struct fb_event *evdata = data;
+	int fb_blank = *(int *)evdata->data;
+	int i;
+
+	if (event != FB_EVENT_BLANK)
+		return 0;
+
+	if (lt7911d->fb_blank == fb_blank)
+		return 0;
+
+	if (fb_blank == FB_BLANK_UNBLANK) {
+		for (i = 0; i < lt7911d->gpios->ndescs; i++)
+			gpiod_direction_output(lt7911d->gpios->desc[i], 1);
+		msleep(20);
+		for (i = 0; i < lt7911d->gpios->ndescs; i++)
+			gpiod_direction_output(lt7911d->gpios->desc[i], 0);
+		msleep(500);
+	}
+
+	lt7911d->fb_blank = fb_blank;
+
+	return 0;
+}
+
+static int lt7911d_fb_notifier_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct lt7911d *lt7911d;
+	int i, ret;
+
+	lt7911d = devm_kzalloc(dev, sizeof(*lt7911d), GFP_KERNEL);
+	if (!lt7911d)
+		return -ENOMEM;
+
+	lt7911d->dev = dev;
+	platform_set_drvdata(pdev, lt7911d);
+
+	lt7911d->gpios = devm_gpiod_get_array(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(lt7911d->gpios))
+		return dev_err_probe(dev, PTR_ERR(lt7911d->gpios),
+				     "failed to acquire reset gpio\n");
+
+	for (i = 0; i < lt7911d->gpios->ndescs; i++)
+		gpiod_set_consumer_name(lt7911d->gpios->desc[i], "lt7911d-reset");
+
+	lt7911d->fb_blank = FB_BLANK_UNBLANK;
+	lt7911d->fb_notif.notifier_call = lt7911d_fb_notifier_callback;
+	ret = fb_register_client(&lt7911d->fb_notif);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to register fb client\n");
+
+	return 0;
+}
+
+static int lt7911d_fb_notifier_remove(struct platform_device *pdev)
+{
+	struct lt7911d *lt7911d = platform_get_drvdata(pdev);
+
+	fb_unregister_client(&lt7911d->fb_notif);
+
+	return 0;
+}
+
+static void lt7911d_fb_notifier_shutdown(struct platform_device *pdev)
+{
+	struct lt7911d *lt7911d = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < lt7911d->gpios->ndescs; i++)
+		gpiod_direction_output(lt7911d->gpios->desc[i], 1);
+	msleep(20);
+}
+
+static const struct of_device_id lt7911d_fb_notifier_of_match[] = {
+	{ .compatible = "lontium,lt7911d-fb-notifier" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, lt7911d_fb_notifier_of_match);
+
+static struct platform_driver lt7911d_fb_notifier_driver = {
+	.driver = {
+		.name = "lt7911d-fb-notifier",
+		.of_match_table = lt7911d_fb_notifier_of_match,
+	},
+	.probe = lt7911d_fb_notifier_probe,
+	.remove = lt7911d_fb_notifier_remove,
+	.shutdown = lt7911d_fb_notifier_shutdown,
+};
+
+module_platform_driver(lt7911d_fb_notifier_driver);
+
+MODULE_DESCRIPTION("Lontium LT7911D FB Notifier");
+MODULE_LICENSE("GPL");