From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1753749AbeCFN6Q (ORCPT <rfc822;w@1wt.eu>);
        Tue, 6 Mar 2018 08:58:16 -0500
Received: from mail.bootlin.com ([62.4.15.54]:35064 "EHLO mail.bootlin.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S932688AbeCFN5T (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 6 Mar 2018 08:57:19 -0500
From: Maxime Ripard <maxime.ripard@bootlin.com>
To: Thierry Reding <thierry.reding@gmail.com>,
        Chen-Yu Tsai <wens@csie.org>,
        Maxime Ripard <maxime.ripard@bootlin.com>,
        Mark Rutland <mark.rutland@arm.com>, Rob Herring <robh+dt@kernel.org>
Cc: dri-devel@lists.freedesktop.org, Gustavo Padovan <gustavo@padovan.org>,
        Daniel Vetter <daniel.vetter@intel.com>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Sean Paul <seanpaul@chromium.org>, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
        Maxime Ripard <maxime.ripard@free-electrons.com>
Subject: [PATCH v3 5/7] drm/panel: Add Ilitek ILI9881c panel driver
Date: Tue,  6 Mar 2018 14:56:02 +0100
Message-Id: <4ebd47038b1ee1cc6b7d9738313f43f985268463.1520344489.git-series.maxime.ripard@bootlin.com>
X-Mailer: git-send-email 2.14.3
In-Reply-To: <cover.14d017af44a2140bea674731b60a0dd7f992f5f6.1520344489.git-series.maxime.ripard@bootlin.com>
References: <cover.14d017af44a2140bea674731b60a0dd7f992f5f6.1520344489.git-series.maxime.ripard@bootlin.com>
In-Reply-To: <cover.14d017af44a2140bea674731b60a0dd7f992f5f6.1520344489.git-series.maxime.ripard@bootlin.com>
References: <cover.14d017af44a2140bea674731b60a0dd7f992f5f6.1520344489.git-series.maxime.ripard@bootlin.com>
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Maxime Ripard <maxime.ripard@free-electrons.com>

The LHR050H41 panel is the panel shipped with the BananaPi M2-Magic, and is
based on the Ilitek ILI9881c Controller. Add a driver for it, modelled
after the other Ilitek controller drivers.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/panel/Kconfig                 |   9 +-
 drivers/gpu/drm/panel/Makefile                |   1 +-
 drivers/gpu/drm/panel/panel-ilitek-ili9881c.c | 506 +++++++++++++++++++-
 3 files changed, 516 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-ilitek-ili9881c.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 6ba4031f3919..bc94b4e4ae48 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -36,6 +36,15 @@ config DRM_PANEL_ILITEK_IL9322
 	  Say Y here if you want to enable support for Ilitek IL9322
 	  QVGA (320x240) RGB, YUV and ITU-T BT.656 panels.
 
+config DRM_PANEL_ILITEK_ILI9881C
+	tristate "Ilitek ILI9881C-based panels"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y if you want to enable support for panels based on the
+	  Ilitek ILI9881c controller.
+
 config DRM_PANEL_INNOLUX_P079ZCA
 	tristate "Innolux P079ZCA panel"
 	depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 6d251ebc568c..3ab387be4dbf 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -2,6 +2,7 @@
 obj-$(CONFIG_DRM_PANEL_LVDS) += panel-lvds.o
 obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
+obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
 obj-$(CONFIG_DRM_PANEL_INNOLUX_P079ZCA) += panel-innolux-p079zca.o
 obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
 obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c b/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c
new file mode 100644
index 000000000000..8a1b65c05ba1
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c
@@ -0,0 +1,506 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2017, Free Electrons
+ * Author: Maxime Ripard <maxime.ripard@free-electrons.com>
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/fb.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/gpio/consumer.h>
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+
+#include <video/mipi_display.h>
+
+struct ili9881c {
+	struct drm_panel	panel;
+	struct mipi_dsi_device	*dsi;
+
+	struct backlight_device *backlight;
+	struct gpio_desc	*power;
+	struct gpio_desc	*reset;
+};
+
+enum ili9881c_op {
+	ILI9881C_SWITCH_PAGE,
+	ILI9881C_COMMAND,
+};
+
+struct ili9881c_instr {
+	enum ili9881c_op	op;
+
+	union arg {
+		struct cmd {
+			u8	cmd;
+			u8	data;
+		} cmd;
+		u8	page;
+	} arg;
+};
+
+#define ILI9881C_SWITCH_PAGE_INSTR(_page)	\
+	{					\
+		.op = ILI9881C_SWITCH_PAGE,	\
+		.arg = {			\
+			.page = (_page),	\
+		},				\
+	}
+
+#define ILI9881C_COMMAND_INSTR(_cmd, _data)		\
+	{						\
+		.op = ILI9881C_COMMAND,		\
+		.arg = {				\
+			.cmd = {			\
+				.cmd = (_cmd),		\
+				.data = (_data),	\
+			},				\
+		},					\
+	}
+
+static struct ili9881c_instr ili9881c_init[] = {
+	ILI9881C_SWITCH_PAGE_INSTR(3),
+	ILI9881C_COMMAND_INSTR(0x01, 0x00),
+	ILI9881C_COMMAND_INSTR(0x02, 0x00),
+	ILI9881C_COMMAND_INSTR(0x03, 0x73),
+	ILI9881C_COMMAND_INSTR(0x04, 0x03),
+	ILI9881C_COMMAND_INSTR(0x05, 0x00),
+	ILI9881C_COMMAND_INSTR(0x06, 0x06),
+	ILI9881C_COMMAND_INSTR(0x07, 0x06),
+	ILI9881C_COMMAND_INSTR(0x08, 0x00),
+	ILI9881C_COMMAND_INSTR(0x09, 0x18),
+	ILI9881C_COMMAND_INSTR(0x0a, 0x04),
+	ILI9881C_COMMAND_INSTR(0x0b, 0x00),
+	ILI9881C_COMMAND_INSTR(0x0c, 0x02),
+	ILI9881C_COMMAND_INSTR(0x0d, 0x03),
+	ILI9881C_COMMAND_INSTR(0x0e, 0x00),
+	ILI9881C_COMMAND_INSTR(0x0f, 0x25),
+	ILI9881C_COMMAND_INSTR(0x10, 0x25),
+	ILI9881C_COMMAND_INSTR(0x11, 0x00),
+	ILI9881C_COMMAND_INSTR(0x12, 0x00),
+	ILI9881C_COMMAND_INSTR(0x13, 0x00),
+	ILI9881C_COMMAND_INSTR(0x14, 0x00),
+	ILI9881C_COMMAND_INSTR(0x15, 0x00),
+	ILI9881C_COMMAND_INSTR(0x16, 0x0C),
+	ILI9881C_COMMAND_INSTR(0x17, 0x00),
+	ILI9881C_COMMAND_INSTR(0x18, 0x00),
+	ILI9881C_COMMAND_INSTR(0x19, 0x00),
+	ILI9881C_COMMAND_INSTR(0x1a, 0x00),
+	ILI9881C_COMMAND_INSTR(0x1b, 0x00),
+	ILI9881C_COMMAND_INSTR(0x1c, 0x00),
+	ILI9881C_COMMAND_INSTR(0x1d, 0x00),
+	ILI9881C_COMMAND_INSTR(0x1e, 0xC0),
+	ILI9881C_COMMAND_INSTR(0x1f, 0x80),
+	ILI9881C_COMMAND_INSTR(0x20, 0x04),
+	ILI9881C_COMMAND_INSTR(0x21, 0x01),
+	ILI9881C_COMMAND_INSTR(0x22, 0x00),
+	ILI9881C_COMMAND_INSTR(0x23, 0x00),
+	ILI9881C_COMMAND_INSTR(0x24, 0x00),
+	ILI9881C_COMMAND_INSTR(0x25, 0x00),
+	ILI9881C_COMMAND_INSTR(0x26, 0x00),
+	ILI9881C_COMMAND_INSTR(0x27, 0x00),
+	ILI9881C_COMMAND_INSTR(0x28, 0x33),
+	ILI9881C_COMMAND_INSTR(0x29, 0x03),
+	ILI9881C_COMMAND_INSTR(0x2a, 0x00),
+	ILI9881C_COMMAND_INSTR(0x2b, 0x00),
+	ILI9881C_COMMAND_INSTR(0x2c, 0x00),
+	ILI9881C_COMMAND_INSTR(0x2d, 0x00),
+	ILI9881C_COMMAND_INSTR(0x2e, 0x00),
+	ILI9881C_COMMAND_INSTR(0x2f, 0x00),
+	ILI9881C_COMMAND_INSTR(0x30, 0x00),
+	ILI9881C_COMMAND_INSTR(0x31, 0x00),
+	ILI9881C_COMMAND_INSTR(0x32, 0x00),
+	ILI9881C_COMMAND_INSTR(0x33, 0x00),
+	ILI9881C_COMMAND_INSTR(0x34, 0x04),
+	ILI9881C_COMMAND_INSTR(0x35, 0x00),
+	ILI9881C_COMMAND_INSTR(0x36, 0x00),
+	ILI9881C_COMMAND_INSTR(0x37, 0x00),
+	ILI9881C_COMMAND_INSTR(0x38, 0x3C),
+	ILI9881C_COMMAND_INSTR(0x39, 0x00),
+	ILI9881C_COMMAND_INSTR(0x3a, 0x00),
+	ILI9881C_COMMAND_INSTR(0x3b, 0x00),
+	ILI9881C_COMMAND_INSTR(0x3c, 0x00),
+	ILI9881C_COMMAND_INSTR(0x3d, 0x00),
+	ILI9881C_COMMAND_INSTR(0x3e, 0x00),
+	ILI9881C_COMMAND_INSTR(0x3f, 0x00),
+	ILI9881C_COMMAND_INSTR(0x40, 0x00),
+	ILI9881C_COMMAND_INSTR(0x41, 0x00),
+	ILI9881C_COMMAND_INSTR(0x42, 0x00),
+	ILI9881C_COMMAND_INSTR(0x43, 0x00),
+	ILI9881C_COMMAND_INSTR(0x44, 0x00),
+	ILI9881C_COMMAND_INSTR(0x50, 0x01),
+	ILI9881C_COMMAND_INSTR(0x51, 0x23),
+	ILI9881C_COMMAND_INSTR(0x52, 0x45),
+	ILI9881C_COMMAND_INSTR(0x53, 0x67),
+	ILI9881C_COMMAND_INSTR(0x54, 0x89),
+	ILI9881C_COMMAND_INSTR(0x55, 0xab),
+	ILI9881C_COMMAND_INSTR(0x56, 0x01),
+	ILI9881C_COMMAND_INSTR(0x57, 0x23),
+	ILI9881C_COMMAND_INSTR(0x58, 0x45),
+	ILI9881C_COMMAND_INSTR(0x59, 0x67),
+	ILI9881C_COMMAND_INSTR(0x5a, 0x89),
+	ILI9881C_COMMAND_INSTR(0x5b, 0xab),
+	ILI9881C_COMMAND_INSTR(0x5c, 0xcd),
+	ILI9881C_COMMAND_INSTR(0x5d, 0xef),
+	ILI9881C_COMMAND_INSTR(0x5e, 0x11),
+	ILI9881C_COMMAND_INSTR(0x5f, 0x02),
+	ILI9881C_COMMAND_INSTR(0x60, 0x02),
+	ILI9881C_COMMAND_INSTR(0x61, 0x02),
+	ILI9881C_COMMAND_INSTR(0x62, 0x02),
+	ILI9881C_COMMAND_INSTR(0x63, 0x02),
+	ILI9881C_COMMAND_INSTR(0x64, 0x02),
+	ILI9881C_COMMAND_INSTR(0x65, 0x02),
+	ILI9881C_COMMAND_INSTR(0x66, 0x02),
+	ILI9881C_COMMAND_INSTR(0x67, 0x02),
+	ILI9881C_COMMAND_INSTR(0x68, 0x02),
+	ILI9881C_COMMAND_INSTR(0x69, 0x02),
+	ILI9881C_COMMAND_INSTR(0x6a, 0x0C),
+	ILI9881C_COMMAND_INSTR(0x6b, 0x02),
+	ILI9881C_COMMAND_INSTR(0x6c, 0x0F),
+	ILI9881C_COMMAND_INSTR(0x6d, 0x0E),
+	ILI9881C_COMMAND_INSTR(0x6e, 0x0D),
+	ILI9881C_COMMAND_INSTR(0x6f, 0x06),
+	ILI9881C_COMMAND_INSTR(0x70, 0x07),
+	ILI9881C_COMMAND_INSTR(0x71, 0x02),
+	ILI9881C_COMMAND_INSTR(0x72, 0x02),
+	ILI9881C_COMMAND_INSTR(0x73, 0x02),
+	ILI9881C_COMMAND_INSTR(0x74, 0x02),
+	ILI9881C_COMMAND_INSTR(0x75, 0x02),
+	ILI9881C_COMMAND_INSTR(0x76, 0x02),
+	ILI9881C_COMMAND_INSTR(0x77, 0x02),
+	ILI9881C_COMMAND_INSTR(0x78, 0x02),
+	ILI9881C_COMMAND_INSTR(0x79, 0x02),
+	ILI9881C_COMMAND_INSTR(0x7a, 0x02),
+	ILI9881C_COMMAND_INSTR(0x7b, 0x02),
+	ILI9881C_COMMAND_INSTR(0x7c, 0x02),
+	ILI9881C_COMMAND_INSTR(0x7d, 0x02),
+	ILI9881C_COMMAND_INSTR(0x7e, 0x02),
+	ILI9881C_COMMAND_INSTR(0x7f, 0x02),
+	ILI9881C_COMMAND_INSTR(0x80, 0x0C),
+	ILI9881C_COMMAND_INSTR(0x81, 0x02),
+	ILI9881C_COMMAND_INSTR(0x82, 0x0F),
+	ILI9881C_COMMAND_INSTR(0x83, 0x0E),
+	ILI9881C_COMMAND_INSTR(0x84, 0x0D),
+	ILI9881C_COMMAND_INSTR(0x85, 0x06),
+	ILI9881C_COMMAND_INSTR(0x86, 0x07),
+	ILI9881C_COMMAND_INSTR(0x87, 0x02),
+	ILI9881C_COMMAND_INSTR(0x88, 0x02),
+	ILI9881C_COMMAND_INSTR(0x89, 0x02),
+	ILI9881C_COMMAND_INSTR(0x8A, 0x02),
+	ILI9881C_SWITCH_PAGE_INSTR(4),
+	ILI9881C_COMMAND_INSTR(0x6C, 0x15),
+	ILI9881C_COMMAND_INSTR(0x6E, 0x22),
+	ILI9881C_COMMAND_INSTR(0x6F, 0x33),
+	ILI9881C_COMMAND_INSTR(0x3A, 0xA4),
+	ILI9881C_COMMAND_INSTR(0x8D, 0x0D),
+	ILI9881C_COMMAND_INSTR(0x87, 0xBA),
+	ILI9881C_COMMAND_INSTR(0x26, 0x76),
+	ILI9881C_COMMAND_INSTR(0xB2, 0xD1),
+	ILI9881C_SWITCH_PAGE_INSTR(1),
+	ILI9881C_COMMAND_INSTR(0x22, 0x0A),
+	ILI9881C_COMMAND_INSTR(0x53, 0xDC),
+	ILI9881C_COMMAND_INSTR(0x55, 0xA7),
+	ILI9881C_COMMAND_INSTR(0x50, 0x78),
+	ILI9881C_COMMAND_INSTR(0x51, 0x78),
+	ILI9881C_COMMAND_INSTR(0x31, 0x02),
+	ILI9881C_COMMAND_INSTR(0x60, 0x14),
+	ILI9881C_COMMAND_INSTR(0xA0, 0x2A),
+	ILI9881C_COMMAND_INSTR(0xA1, 0x39),
+	ILI9881C_COMMAND_INSTR(0xA2, 0x46),
+	ILI9881C_COMMAND_INSTR(0xA3, 0x0e),
+	ILI9881C_COMMAND_INSTR(0xA4, 0x12),
+	ILI9881C_COMMAND_INSTR(0xA5, 0x25),
+	ILI9881C_COMMAND_INSTR(0xA6, 0x19),
+	ILI9881C_COMMAND_INSTR(0xA7, 0x1d),
+	ILI9881C_COMMAND_INSTR(0xA8, 0xa6),
+	ILI9881C_COMMAND_INSTR(0xA9, 0x1C),
+	ILI9881C_COMMAND_INSTR(0xAA, 0x29),
+	ILI9881C_COMMAND_INSTR(0xAB, 0x85),
+	ILI9881C_COMMAND_INSTR(0xAC, 0x1C),
+	ILI9881C_COMMAND_INSTR(0xAD, 0x1B),
+	ILI9881C_COMMAND_INSTR(0xAE, 0x51),
+	ILI9881C_COMMAND_INSTR(0xAF, 0x22),
+	ILI9881C_COMMAND_INSTR(0xB0, 0x2d),
+	ILI9881C_COMMAND_INSTR(0xB1, 0x4f),
+	ILI9881C_COMMAND_INSTR(0xB2, 0x59),
+	ILI9881C_COMMAND_INSTR(0xB3, 0x3F),
+	ILI9881C_COMMAND_INSTR(0xC0, 0x2A),
+	ILI9881C_COMMAND_INSTR(0xC1, 0x3a),
+	ILI9881C_COMMAND_INSTR(0xC2, 0x45),
+	ILI9881C_COMMAND_INSTR(0xC3, 0x0e),
+	ILI9881C_COMMAND_INSTR(0xC4, 0x11),
+	ILI9881C_COMMAND_INSTR(0xC5, 0x24),
+	ILI9881C_COMMAND_INSTR(0xC6, 0x1a),
+	ILI9881C_COMMAND_INSTR(0xC7, 0x1c),
+	ILI9881C_COMMAND_INSTR(0xC8, 0xaa),
+	ILI9881C_COMMAND_INSTR(0xC9, 0x1C),
+	ILI9881C_COMMAND_INSTR(0xCA, 0x29),
+	ILI9881C_COMMAND_INSTR(0xCB, 0x96),
+	ILI9881C_COMMAND_INSTR(0xCC, 0x1C),
+	ILI9881C_COMMAND_INSTR(0xCD, 0x1B),
+	ILI9881C_COMMAND_INSTR(0xCE, 0x51),
+	ILI9881C_COMMAND_INSTR(0xCF, 0x22),
+	ILI9881C_COMMAND_INSTR(0xD0, 0x2b),
+	ILI9881C_COMMAND_INSTR(0xD1, 0x4b),
+	ILI9881C_COMMAND_INSTR(0xD2, 0x59),
+	ILI9881C_COMMAND_INSTR(0xD3, 0x3F),
+};
+
+static inline struct ili9881c *panel_to_ili9881c(struct drm_panel *panel)
+{
+	return container_of(panel, struct ili9881c, panel);
+}
+
+static int ili9881c_switch_page(struct ili9881c *ctx, u8 page)
+{
+	u8 buf[4] = { 0xff, 0x98, 0x81, page };
+	int ret;
+
+	ret = mipi_dsi_dcs_write_buffer(ctx->dsi, buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int ili9881c_send_cmd_data(struct ili9881c *ctx, u8 cmd, u8 data)
+{
+	u8 buf[2] = { cmd, data };
+	int ret;
+
+	ret = mipi_dsi_dcs_write_buffer(ctx->dsi, buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int ili9881c_prepare(struct drm_panel *panel)
+{
+	struct ili9881c *ctx = panel_to_ili9881c(panel);
+	int i, ret;
+
+	/* Power the panel */
+	gpiod_set_value(ctx->power, 1);
+	mdelay(5);
+
+	/* And reset it */
+	gpiod_set_value(ctx->reset, 1);
+	mdelay(20);
+
+	gpiod_set_value(ctx->reset, 0);
+	mdelay(20);
+
+	for (i = 0; i < ARRAY_SIZE(ili9881c_init); i++) {
+		struct ili9881c_instr *instr = &ili9881c_init[i];
+
+		if (instr->op == ILI9881C_SWITCH_PAGE)
+			ret = ili9881c_switch_page(ctx, instr->arg.page);
+		else if (instr->op == ILI9881C_COMMAND)
+			ret = ili9881c_send_cmd_data(ctx, instr->arg.cmd.cmd,
+						      instr->arg.cmd.data);
+
+		if (ret)
+			return ret;
+	}
+
+	ret = ili9881c_switch_page(ctx, 0);
+	if (ret)
+		return ret;
+
+	ret = mipi_dsi_dcs_set_tear_on(ctx->dsi, MIPI_DSI_DCS_TEAR_MODE_VBLANK);
+	if (ret)
+		return ret;
+
+	mipi_dsi_dcs_exit_sleep_mode(ctx->dsi);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void ili9881c_enable_bl(struct ili9881c *ctx, bool enable)
+{
+	if (!ctx->backlight)
+		return;
+
+	if (enable) {
+		ctx->backlight->props.state &= ~BL_CORE_FBBLANK;
+		ctx->backlight->props.power = FB_BLANK_UNBLANK;
+	} else {
+		ctx->backlight->props.power = FB_BLANK_POWERDOWN;
+		ctx->backlight->props.state |= BL_CORE_FBBLANK;
+	}
+
+	backlight_update_status(ctx->backlight);
+}
+
+static int ili9881c_enable(struct drm_panel *panel)
+{
+	struct ili9881c *ctx = panel_to_ili9881c(panel);
+
+	mdelay(120);
+
+	mipi_dsi_dcs_set_display_on(ctx->dsi);
+
+	ili9881c_enable_bl(ctx, true);
+
+	return 0;
+}
+
+static int ili9881c_disable(struct drm_panel *panel)
+{
+	struct ili9881c *ctx = panel_to_ili9881c(panel);
+
+	ili9881c_enable_bl(ctx, false);
+
+	return mipi_dsi_dcs_set_display_off(ctx->dsi);
+}
+
+static int ili9881c_unprepare(struct drm_panel *panel)
+{
+	struct ili9881c *ctx = panel_to_ili9881c(panel);
+
+	mipi_dsi_dcs_enter_sleep_mode(ctx->dsi);
+	gpiod_set_value(ctx->power, 0);
+	gpiod_set_value(ctx->reset, 1);
+
+	return 0;
+}
+
+static const struct drm_display_mode default_mode = {
+	.clock		= 62000,
+	.vrefresh	= 60,
+
+	.hdisplay	= 720,
+	.hsync_start	= 720 + 10,
+	.hsync_end	= 720 + 10 + 20,
+	.htotal		= 720 + 10 + 20 + 30,
+
+	.vdisplay	= 1280,
+	.vsync_start	= 1280 + 10,
+	.vsync_end	= 1280 + 10 + 10,
+	.vtotal		= 1280 + 10 + 10 + 20,
+};
+
+static int ili9881c_get_modes(struct drm_panel *panel)
+{
+	struct drm_connector *connector = panel->connector;
+	struct ili9881c *ctx = panel_to_ili9881c(panel);
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(panel->drm, &default_mode);
+	if (!mode) {
+		dev_err(&ctx->dsi->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 = 62;
+	panel->connector->display_info.height_mm = 110;
+
+	return 1;
+}
+
+static const struct drm_panel_funcs ili9881c_funcs = {
+	.prepare	= ili9881c_prepare,
+	.unprepare	= ili9881c_unprepare,
+	.enable		= ili9881c_enable,
+	.disable	= ili9881c_disable,
+	.get_modes	= ili9881c_get_modes,
+};
+
+static int ili9881c_dsi_probe(struct mipi_dsi_device *dsi)
+{
+	struct device_node *np;
+	struct ili9881c *ctx;
+	int ret;
+
+	ctx = devm_kzalloc(&dsi->dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+	mipi_dsi_set_drvdata(dsi, ctx);
+	ctx->dsi = dsi;
+
+	drm_panel_init(&ctx->panel);
+	ctx->panel.dev = &dsi->dev;
+	ctx->panel.funcs = &ili9881c_funcs;
+
+	ctx->power = devm_gpiod_get(&dsi->dev, "power", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->power)) {
+		dev_err(&dsi->dev, "Couldn't get our power GPIO\n");
+		return PTR_ERR(ctx->power);
+	}
+
+	ctx->reset = devm_gpiod_get(&dsi->dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->reset)) {
+		dev_err(&dsi->dev, "Couldn't get our reset GPIO\n");
+		return PTR_ERR(ctx->reset);
+	}
+
+	np = of_parse_phandle(dsi->dev.of_node, "backlight", 0);
+	if (np) {
+		ctx->backlight = of_find_backlight_by_node(np);
+		of_node_put(np);
+
+		if (!ctx->backlight)
+			return -EPROBE_DEFER;
+	}
+
+	ret = drm_panel_add(&ctx->panel);
+	if (ret < 0)
+		return ret;
+
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->lanes = 4;
+
+	return mipi_dsi_attach(dsi);
+}
+
+static int ili9881c_dsi_remove(struct mipi_dsi_device *dsi)
+{
+	struct ili9881c *ctx = mipi_dsi_get_drvdata(dsi);
+
+	mipi_dsi_detach(dsi);
+	drm_panel_remove(&ctx->panel);
+
+	if (ctx->backlight)
+		put_device(&ctx->backlight->dev);
+
+	return 0;
+}
+
+static const struct of_device_id ili9881c_of_match[] = {
+	{ .compatible = "bananapi,lhr050h41" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ili9881c_of_match);
+
+static struct mipi_dsi_driver ili9881c_dsi_driver = {
+	.probe		= ili9881c_dsi_probe,
+	.remove		= ili9881c_dsi_remove,
+	.driver = {
+		.name		= "ili9881c-dsi",
+		.of_match_table	= ili9881c_of_match,
+	},
+};
+module_mipi_dsi_driver(ili9881c_dsi_driver);
+
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_DESCRIPTION("Ilitek ILI9881C Controller Driver");
+MODULE_LICENSE("GPL v2");
-- 
git-series 0.9.1