drm/panel: Add driver for the NEC NL8048HL11 panel

This panel is used on the Zoom2/3/3630 SDP boards.

The code is based on the omapdrm-specific panel-nec-nl8048hl11 driver

v2:
- fix checkpatch warning (lcd == NULL) => (!lcd) (sam)

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190813201101.30980-6-laurent.pinchart@ideasonboard.com

drivers/gpu/drm/panel/Kconfig

@@ -119,6 +119,14 @@ config DRM_PANEL_LG_LG4573
 	  Say Y here if you want to enable support for LG4573 RGB panel.
 	  To compile this driver as a module, choose M here.
 
+config DRM_PANEL_NEC_NL8048HL11
+	tristate "NEC NL8048HL11 RGB panel"
+	depends on GPIOLIB && OF && SPI
+	help
+	  Say Y here if you want to enable support for the NEC NL8048HL11 RGB
+	  panel (found on the Zoom2/3/3630 SDP boards). To compile this driver
+	  as a module, choose M here.
+
 config DRM_PANEL_NOVATEK_NT39016
 	tristate "Novatek NT39016 RGB/SPI panel"
 	depends on OF && SPI

drivers/gpu/drm/panel/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
 obj-$(CONFIG_DRM_PANEL_KINGDISPLAY_KD097D04) += panel-kingdisplay-kd097d04.o
 obj-$(CONFIG_DRM_PANEL_LG_LB035Q02) += panel-lg-lb035q02.o
 obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
+obj-$(CONFIG_DRM_PANEL_NEC_NL8048HL11) += panel-nec-nl8048hl11.o
 obj-$(CONFIG_DRM_PANEL_NOVATEK_NT39016) += panel-novatek-nt39016.o
 obj-$(CONFIG_DRM_PANEL_OLIMEX_LCD_OLINUXINO) += panel-olimex-lcd-olinuxino.o
 obj-$(CONFIG_DRM_PANEL_ORISETECH_OTM8009A) += panel-orisetech-otm8009a.o

drivers/gpu/drm/panel/panel-lg-lb035q02.c

@@ -180,7 +180,7 @@ static int lb035q02_probe(struct spi_device *spi)
 	int ret;
 
 	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
-	if (lcd == NULL)
+	if (!lcd)
 		return -ENOMEM;
 
 	spi_set_drvdata(spi, lcd);

drivers/gpu/drm/panel/panel-nec-nl8048hl11.c

@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * NEC NL8048HL11 Panel Driver
+ *
+ * Copyright (C) 2019 Texas Instruments Incorporated
+ *
+ * Based on the omapdrm-specific panel-nec-nl8048hl11 driver
+ *
+ * Copyright (C) 2010 Texas Instruments Incorporated
+ * Author: Erik Gilling <konkers@android.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/spi/spi.h>
+
+#include <drm/drm_connector.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+
+struct nl8048_panel {
+	struct drm_panel panel;
+
+	struct spi_device *spi;
+	struct gpio_desc *reset_gpio;
+};
+
+#define to_nl8048_device(p) container_of(p, struct nl8048_panel, panel)
+
+static int nl8048_write(struct nl8048_panel *lcd, unsigned char addr,
+			unsigned char value)
+{
+	u8 data[4] = { value, 0x01, addr, 0x00 };
+	int ret;
+
+	ret = spi_write(lcd->spi, data, sizeof(data));
+	if (ret)
+		dev_err(&lcd->spi->dev, "SPI write to %u failed: %d\n",
+			addr, ret);
+
+	return ret;
+}
+
+static int nl8048_init(struct nl8048_panel *lcd)
+{
+	static const struct {
+		unsigned char addr;
+		unsigned char data;
+	} nl8048_init_seq[] = {
+		{   3, 0x01 }, {   0, 0x00 }, {   1, 0x01 }, {   4, 0x00 },
+		{   5, 0x14 }, {   6, 0x24 }, {  16, 0xd7 }, {  17, 0x00 },
+		{  18, 0x00 }, {  19, 0x55 }, {  20, 0x01 }, {  21, 0x70 },
+		{  22, 0x1e }, {  23, 0x25 }, {  24, 0x25 }, {  25, 0x02 },
+		{  26, 0x02 }, {  27, 0xa0 }, {  32, 0x2f }, {  33, 0x0f },
+		{  34, 0x0f }, {  35, 0x0f }, {  36, 0x0f }, {  37, 0x0f },
+		{  38, 0x0f }, {  39, 0x00 }, {  40, 0x02 }, {  41, 0x02 },
+		{  42, 0x02 }, {  43, 0x0f }, {  44, 0x0f }, {  45, 0x0f },
+		{  46, 0x0f }, {  47, 0x0f }, {  48, 0x0f }, {  49, 0x0f },
+		{  50, 0x00 }, {  51, 0x02 }, {  52, 0x02 }, {  53, 0x02 },
+		{  80, 0x0c }, {  83, 0x42 }, {  84, 0x42 }, {  85, 0x41 },
+		{  86, 0x14 }, {  89, 0x88 }, {  90, 0x01 }, {  91, 0x00 },
+		{  92, 0x02 }, {  93, 0x0c }, {  94, 0x1c }, {  95, 0x27 },
+		{  98, 0x49 }, {  99, 0x27 }, { 102, 0x76 }, { 103, 0x27 },
+		{ 112, 0x01 }, { 113, 0x0e }, { 114, 0x02 }, { 115, 0x0c },
+		{ 118, 0x0c }, { 121, 0x30 }, { 130, 0x00 }, { 131, 0x00 },
+		{ 132, 0xfc }, { 134, 0x00 }, { 136, 0x00 }, { 138, 0x00 },
+		{ 139, 0x00 }, { 140, 0x00 }, { 141, 0xfc }, { 143, 0x00 },
+		{ 145, 0x00 }, { 147, 0x00 }, { 148, 0x00 }, { 149, 0x00 },
+		{ 150, 0xfc }, { 152, 0x00 }, { 154, 0x00 }, { 156, 0x00 },
+		{ 157, 0x00 },
+	};
+
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < ARRAY_SIZE(nl8048_init_seq); ++i) {
+		ret = nl8048_write(lcd, nl8048_init_seq[i].addr,
+				   nl8048_init_seq[i].data);
+		if (ret < 0)
+			return ret;
+	}
+
+	udelay(20);
+
+	return nl8048_write(lcd, 2, 0x00);
+}
+
+static int nl8048_disable(struct drm_panel *panel)
+{
+	struct nl8048_panel *lcd = to_nl8048_device(panel);
+
+	gpiod_set_value_cansleep(lcd->reset_gpio, 0);
+
+	return 0;
+}
+
+static int nl8048_enable(struct drm_panel *panel)
+{
+	struct nl8048_panel *lcd = to_nl8048_device(panel);
+
+	gpiod_set_value_cansleep(lcd->reset_gpio, 1);
+
+	return 0;
+}
+
+static const struct drm_display_mode nl8048_mode = {
+	/*  NEC PIX Clock Ratings MIN:21.8MHz TYP:23.8MHz MAX:25.7MHz */
+	.clock	= 23800,
+	.hdisplay = 800,
+	.hsync_start = 800 + 6,
+	.hsync_end = 800 + 6 + 1,
+	.htotal = 800 + 6 + 1 + 4,
+	.vdisplay = 480,
+	.vsync_start = 480 + 3,
+	.vsync_end = 480 + 3 + 1,
+	.vtotal = 480 + 3 + 1 + 4,
+	.vrefresh = 60,
+	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+	.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	.width_mm = 89,
+	.height_mm = 53,
+};
+
+static int nl8048_get_modes(struct drm_panel *panel)
+{
+	struct drm_connector *connector = panel->connector;
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(panel->drm, &nl8048_mode);
+	if (!mode)
+		return -ENOMEM;
+
+	drm_mode_set_name(mode);
+	drm_mode_probed_add(connector, mode);
+
+	connector->display_info.width_mm = nl8048_mode.width_mm;
+	connector->display_info.height_mm = nl8048_mode.height_mm;
+	connector->display_info.bus_flags = DRM_BUS_FLAG_DE_HIGH
+					  | DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE
+					  | DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
+
+	return 1;
+}
+
+static const struct drm_panel_funcs nl8048_funcs = {
+	.disable = nl8048_disable,
+	.enable = nl8048_enable,
+	.get_modes = nl8048_get_modes,
+};
+
+static int __maybe_unused nl8048_suspend(struct device *dev)
+{
+	struct nl8048_panel *lcd = dev_get_drvdata(dev);
+
+	nl8048_write(lcd, 2, 0x01);
+	msleep(40);
+
+	return 0;
+}
+
+static int __maybe_unused nl8048_resume(struct device *dev)
+{
+	struct nl8048_panel *lcd = dev_get_drvdata(dev);
+
+	/* Reinitialize the panel. */
+	spi_setup(lcd->spi);
+	nl8048_write(lcd, 2, 0x00);
+	nl8048_init(lcd);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(nl8048_pm_ops, nl8048_suspend, nl8048_resume);
+
+static int nl8048_probe(struct spi_device *spi)
+{
+	struct nl8048_panel *lcd;
+	int ret;
+
+	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
+	if (lcd == NULL)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, lcd);
+	lcd->spi = spi;
+
+	lcd->reset_gpio = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(lcd->reset_gpio)) {
+		dev_err(&spi->dev, "failed to parse reset gpio\n");
+		return PTR_ERR(lcd->reset_gpio);
+	}
+
+	spi->mode = SPI_MODE_0;
+	spi->bits_per_word = 32;
+
+	ret = spi_setup(spi);
+	if (ret < 0) {
+		dev_err(&spi->dev, "failed to setup SPI: %d\n", ret);
+		return ret;
+	}
+
+	ret = nl8048_init(lcd);
+	if (ret < 0)
+		return ret;
+
+	drm_panel_init(&lcd->panel);
+	lcd->panel.dev = &lcd->spi->dev;
+	lcd->panel.funcs = &nl8048_funcs;
+
+	return drm_panel_add(&lcd->panel);
+}
+
+static int nl8048_remove(struct spi_device *spi)
+{
+	struct nl8048_panel *lcd = spi_get_drvdata(spi);
+
+	drm_panel_remove(&lcd->panel);
+	drm_panel_disable(&lcd->panel);
+	drm_panel_unprepare(&lcd->panel);
+
+	return 0;
+}
+
+static const struct of_device_id nl8048_of_match[] = {
+	{ .compatible = "nec,nl8048hl11", },
+	{ /* sentinel */ },
+};
+
+MODULE_DEVICE_TABLE(of, nl8048_of_match);
+
+static struct spi_driver nl8048_driver = {
+	.probe		= nl8048_probe,
+	.remove		= nl8048_remove,
+	.driver		= {
+		.name	= "panel-nec-nl8048hl11",
+		.pm	= &nl8048_pm_ops,
+		.of_match_table = nl8048_of_match,
+	},
+};
+
+module_spi_driver(nl8048_driver);
+
+MODULE_ALIAS("spi:nec,nl8048hl11");
+MODULE_AUTHOR("Erik Gilling <konkers@android.com>");
+MODULE_DESCRIPTION("NEC-NL8048HL11 Driver");
+MODULE_LICENSE("GPL");