[PATCH v2] drm/panel: add lg4573 driver

[Heiko Schocher <hs@denx.de>]

Add support for LG LG4573 480x800 4,3" panel. the LG4573
is used on the LG LCD LB043WV2-SD01, an industrial 4.3" TFT
panel with SPI control interface.

Signed-off-by: Heiko Schocher <hs@denx.de>

---

Changes in v2:
- add comments from Thierry Reding:
  - fix some spelling issues
  - remove "power-on-delay"
  - remove display timings usage from DT, instead specify the
    timing in the driver.
  - change config symbol to DRM_PANEL_LG_LG4573
  - change filename to panel-lg-lg4573.c
  - get rid of power_on_delay
  - use cpu_to_be16()
  - rework lg4573_spi_write_u16_array()
  - introduce lg4573_spi_write_dcs()
  - reworked error reporting

 .../devicetree/bindings/panel/lg,lg4573.txt        |  19 +
 drivers/gpu/drm/panel/Kconfig                      |   8 +
 drivers/gpu/drm/panel/Makefile                     |   1 +
 drivers/gpu/drm/panel/panel-lg-lg4573.c            | 382 +++++++++++++++++++++
 4 files changed, 410 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/panel/lg,lg4573.txt
 create mode 100644 drivers/gpu/drm/panel/panel-lg-lg4573.c

diff --git a/Documentation/devicetree/bindings/panel/lg,lg4573.txt b/Documentation/devicetree/bindings/panel/lg,lg4573.txt
new file mode 100644
index 0000000..824441f
--- /dev/null
+++ b/Documentation/devicetree/bindings/panel/lg,lg4573.txt
@@ -0,0 +1,19 @@
+LG LG4573 TFT Liquid Crystal Display with SPI control bus
+
+Required properties:
+  - compatible: "lg,lg4573"
+  - reg: address of the panel on the SPI bus
+
+The panel must obey rules for SPI slave device specified in document [1].
+
+[1]: Documentation/devicetree/bindings/spi/spi-bus.txt
+
+Example:
+
+	lcd_panel: display@0 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "lg,lg4573";
+		spi-max-frequency = <10000000>;
+		reg = <0>;
+	};
diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 6d64c7b..e7a4d16 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -23,6 +23,14 @@ config DRM_PANEL_LD9040
 	depends on OF && SPI
 	select VIDEOMODE_HELPERS
 
+config DRM_PANEL_LG_LG4573
+	tristate "LG4573 RGB/SPI panel"
+	depends on OF && SPI
+	select VIDEOMODE_HELPERS
+	help
+	  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_S6E8AA0
 	tristate "S6E8AA0 DSI video mode panel"
 	depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 4b2a043..437e8bf 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -1,4 +1,5 @@
 obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o
 obj-$(CONFIG_DRM_PANEL_LD9040) += panel-ld9040.o
+obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
 obj-$(CONFIG_DRM_PANEL_S6E8AA0) += panel-s6e8aa0.o
 obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o
diff --git a/drivers/gpu/drm/panel/panel-lg-lg4573.c b/drivers/gpu/drm/panel/panel-lg-lg4573.c
new file mode 100644
index 0000000..9fbe646
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-lg-lg4573.c
@@ -0,0 +1,382 @@
+/*
+ *
+ * Copyright (C) 2015 Heiko Schocher <hs@denx.de>
+ *
+ * from:
+ * drivers/gpu/drm/panel/panel-ld9040.c
+ * ld9040 AMOLED LCD drm_panel driver.
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd
+ * Derived from drivers/video/backlight/ld9040.c
+ *
+ * Andrzej Hajda <a.hajda@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <drm/drmP.h>
+#include <drm/drm_panel.h>
+
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <video/mipi_display.h>
+#include <video/of_videomode.h>
+#include <video/videomode.h>
+
+struct lg4573 {
+	struct drm_panel panel;
+	struct device *dev;
+	struct videomode vm;
+};
+
+static inline struct lg4573 *panel_to_lg4573(struct drm_panel *panel)
+{
+	return container_of(panel, struct lg4573, panel);
+}
+
+static int lg4573_spi_write_u16(struct lg4573 *ctx, u16 data)
+{
+	struct spi_device *spi = to_spi_device(ctx->dev);
+	struct spi_transfer xfer = {
+		.len = 2,
+	};
+	struct spi_message msg;
+	u16 temp = cpu_to_be16(data);
+
+	dev_dbg(ctx->dev, "writing data: %x\n", data);
+	xfer.tx_buf = &temp;
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfer, &msg);
+
+	return spi_sync(spi, &msg);
+}
+
+static int lg4573_spi_write_u16_array(struct lg4573 *ctx, u16 *buf, int cnt)
+{
+	int i;
+	int ret;
+
+	for (i = 0; i < cnt; i++) {
+		ret = lg4573_spi_write_u16(ctx, buf[i]);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
+static int lg4573_spi_write_dcs(struct lg4573 *ctx, u8 dcs)
+{
+	return lg4573_spi_write_u16(ctx, (0x70 << 8 | dcs));
+}
+
+static int lg4573_display_on(struct lg4573 *ctx)
+{
+	int ret;
+
+	ret = lg4573_spi_write_dcs(ctx, MIPI_DCS_EXIT_SLEEP_MODE);
+	if (ret)
+		return ret;
+
+	msleep(5);
+	return lg4573_spi_write_dcs(ctx, MIPI_DCS_SET_DISPLAY_ON);
+}
+
+static int lg4573_display_off(struct lg4573 *ctx)
+{
+	int ret;
+
+	ret = lg4573_spi_write_dcs(ctx, MIPI_DCS_SET_DISPLAY_OFF);
+	if (ret)
+		return ret;
+
+	msleep(120);
+	return lg4573_spi_write_dcs(ctx, MIPI_DCS_ENTER_SLEEP_MODE);
+}
+
+static int lg4573_display_mode_settings(struct lg4573 *ctx)
+{
+	static u16 display_mode_settings[] = {
+	  0x703A,
+	  0x7270,
+	  0x70B1,
+	  0x7208,
+	  0x723B,
+	  0x720F,
+	  0x70B2,
+	  0x7200,
+	  0x72C8,
+	  0x70B3,
+	  0x7200,
+	  0x70B4,
+	  0x7200,
+	  0x70B5,
+	  0x7242,
+	  0x7210,
+	  0x7210,
+	  0x7200,
+	  0x7220,
+	  0x70B6,
+	  0x720B,
+	  0x720F,
+	  0x723C,
+	  0x7213,
+	  0x7213,
+	  0x72E8,
+	  0x70B7,
+	  0x7246,
+	  0x7206,
+	  0x720C,
+	  0x7200,
+	  0x7200,
+	};
+
+	dev_dbg(ctx->dev, "transfer display mode settings\n");
+	return lg4573_spi_write_u16_array(ctx, display_mode_settings,
+					  ARRAY_SIZE(display_mode_settings));
+}
+
+static int lg4573_power_settings(struct lg4573 *ctx)
+{
+	static u16 power_settings[] = {
+	  0x70C0,
+	  0x7201,
+	  0x7211,
+	  0x70C3,
+	  0x7207,
+	  0x7203,
+	  0x7204,
+	  0x7204,
+	  0x7204,
+	  0x70C4,
+	  0x7212,
+	  0x7224,
+	  0x7218,
+	  0x7218,
+	  0x7202,
+	  0x7249,
+	  0x70C5,
+	  0x726F,
+	  0x70C6,
+	  0x7241,
+	  0x7263,
+	};
+
+	dev_dbg(ctx->dev, "transfer power settings\n");
+	return lg4573_spi_write_u16_array(ctx, power_settings,
+					  ARRAY_SIZE(power_settings));
+}
+
+static int lg4573_gamma_settings(struct lg4573 *ctx)
+{
+	static u16 gamma_settings[] = {
+	  0x70D0,
+	  0x7203,
+	  0x7207,
+	  0x7273,
+	  0x7235,
+	  0x7200,
+	  0x7201,
+	  0x7220,
+	  0x7200,
+	  0x7203,
+	  0x70D1,
+	  0x7203,
+	  0x7207,
+	  0x7273,
+	  0x7235,
+	  0x7200,
+	  0x7201,
+	  0x7220,
+	  0x7200,
+	  0x7203,
+	  0x70D2,
+	  0x7203,
+	  0x7207,
+	  0x7273,
+	  0x7235,
+	  0x7200,
+	  0x7201,
+	  0x7220,
+	  0x7200,
+	  0x7203,
+	  0x70D3,
+	  0x7203,
+	  0x7207,
+	  0x7273,
+	  0x7235,
+	  0x7200,
+	  0x7201,
+	  0x7220,
+	  0x7200,
+	  0x7203,
+	  0x70D4,
+	  0x7203,
+	  0x7207,
+	  0x7273,
+	  0x7235,
+	  0x7200,
+	  0x7201,
+	  0x7220,
+	  0x7200,
+	  0x7203,
+	  0x70D5,
+	  0x7203,
+	  0x7207,
+	  0x7273,
+	  0x7235,
+	  0x7200,
+	  0x7201,
+	  0x7220,
+	  0x7200,
+	  0x7203,
+	};
+
+	dev_dbg(ctx->dev, "transfer gamma settings\n");
+	return lg4573_spi_write_u16_array(ctx, gamma_settings,
+					  ARRAY_SIZE(gamma_settings));
+}
+
+static int lg4573_init(struct lg4573 *ctx)
+{
+	int ret;
+
+	dev_dbg(ctx->dev, "initializing LCD\n");
+
+	ret = lg4573_display_mode_settings(ctx);
+	if (ret)
+		return ret;
+
+	ret = lg4573_power_settings(ctx);
+	if (ret)
+		return ret;
+
+	return lg4573_gamma_settings(ctx);
+}
+
+static int lg4573_power_on(struct lg4573 *ctx)
+{
+	return lg4573_display_on(ctx);
+}
+
+static int lg4573_disable(struct drm_panel *panel)
+{
+	struct lg4573 *ctx = panel_to_lg4573(panel);
+
+	return lg4573_display_off(ctx);
+}
+
+static int lg4573_enable(struct drm_panel *panel)
+{
+	struct lg4573 *ctx = panel_to_lg4573(panel);
+	int ret;
+
+	lg4573_init(ctx);
+
+	ret = lg4573_power_on(ctx);
+
+	return ret;
+}
+
+static const struct drm_display_mode default_mode = {
+	.clock = 27000,
+	.hdisplay = 480,
+	.hsync_start = 480 + 10,
+	.hsync_end = 480 + 10 + 59,
+	.htotal = 480 + 10 + 59 + 10,
+	.vdisplay = 800,
+	.vsync_start = 800 + 15,
+	.vsync_end = 800 + 15 + 15,
+	.vtotal = 800 + 15 + 15 + 15,
+	.vrefresh = 60,
+};
+
+static int lg4573_get_modes(struct drm_panel *panel)
+{
+	struct drm_connector *connector = panel->connector;
+	struct drm_device *drm = panel->drm;
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(drm, &default_mode);
+	if (!mode) {
+		dev_err(panel->drm->dev, "failed to add mode %ux%ux@%u\n",
+			default_mode.hdisplay, default_mode.vdisplay,
+			default_mode.vrefresh);
+		return -ENOMEM;
+	}
+	drm_mode_set_name(mode);
+
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+	drm_mode_probed_add(connector, mode);
+	panel->connector->display_info.width_mm = 61;
+	panel->connector->display_info.height_mm = 103;
+
+	return 1;
+}
+
+static const struct drm_panel_funcs lg4573_drm_funcs = {
+	.disable = lg4573_disable,
+	.enable = lg4573_enable,
+	.get_modes = lg4573_get_modes,
+};
+
+static int lg4573_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct lg4573 *ctx;
+	int ret;
+
+	ctx = devm_kzalloc(dev, sizeof(struct lg4573), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, ctx);
+	ctx->dev = dev;
+
+	spi->bits_per_word = 8;
+	ret = spi_setup(spi);
+	if (ret < 0) {
+		dev_err(dev, "SPI setup failed. err = %d\n", ret);
+		return ret;
+	}
+
+	drm_panel_init(&ctx->panel);
+	ctx->panel.dev = dev;
+	ctx->panel.funcs = &lg4573_drm_funcs;
+
+	return drm_panel_add(&ctx->panel);
+}
+
+static int lg4573_remove(struct spi_device *spi)
+{
+	struct lg4573 *ctx = spi_get_drvdata(spi);
+
+	lg4573_display_off(ctx);
+	drm_panel_remove(&ctx->panel);
+
+	return 0;
+}
+
+static const struct of_device_id lg4573_of_match[] = {
+	{ .compatible = "lg,lg4573" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, lg4573_of_match);
+
+static struct spi_driver lg4573_driver = {
+	.probe		= lg4573_probe,
+	.remove		= lg4573_remove,
+	.driver = {
+		.name = "lg4573",
+		.owner = THIS_MODULE,
+		.of_match_table = lg4573_of_match,
+	},
+};
+module_spi_driver(lg4573_driver);
+
+MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
+MODULE_DESCRIPTION("lg4573 LCD Driver");
+MODULE_LICENSE("GPL v2");
-- 
2.1.0