drm/panel: Add Sharp LQ101R1SX01 support

This panel requires dual-channel mode. The device accepts command-mode
data on 8 lanes and will therefore need a dual-channel DSI controller.
The two interfaces that make up this device need to be instantiated in
the controllers that gang up to provide the dual-channel DSI host.

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

4 files changed, 527 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/panel/sharp,lq101r1sx01.txt b/Documentation/devicetree/bindings/panel/sharp,lq101r1sx01.txt
new file mode 100644
index 000000000000..f522bb8e47e1
--- /dev/null
+++ b/Documentation/devicetree/bindings/panel/sharp,lq101r1sx01.txt
@@ -0,0 +1,49 @@
+Sharp Microelectronics 10.1" WQXGA TFT LCD panel
+
+This panel requires a dual-channel DSI host to operate. It supports two modes:
+- left-right: each channel drives the left or right half of the screen
+- even-odd: each channel drives the even or odd lines of the screen
+
+Each of the DSI channels controls a separate DSI peripheral. The peripheral
+driven by the first link (DSI-LINK1), left or even, is considered the primary
+peripheral and controls the device. The 'link2' property contains a phandle
+to the peripheral driven by the second link (DSI-LINK2, right or odd).
+
+Note that in video mode the DSI-LINK1 interface always provides the left/even
+pixels and DSI-LINK2 always provides the right/odd pixels. In command mode it
+is possible to program either link to drive the left/even or right/odd pixels
+but for the sake of consistency this binding assumes that the same assignment
+is chosen as for video mode.
+
+Required properties:
+- compatible: should be "sharp,lq101r1sx01"
+- reg: DSI virtual channel of the peripheral
+
+Required properties (for DSI-LINK1 only):
+- link2: phandle to the DSI peripheral on the secondary link. Note that the
+  presence of this property marks the containing node as DSI-LINK1.
+- power-supply: phandle of the regulator that provides the supply voltage
+
+Optional properties (for DSI-LINK1 only):
+- backlight: phandle of the backlight device attached to the panel
+
+Example:
+
+        dsi@54300000 {
+                panel: panel@0 {
+                        compatible = "sharp,lq101r1sx01";
+                        reg = <0>;
+
+                        link2 = <&secondary>;
+
+                        power-supply = <...>;
+                        backlight = <...>;
+                };
+        };
+
+        dsi@54400000 {
+                secondary: panel@0 {
+                        compatible = "sharp,lq101r1sx01";
+                        reg = <0>;
+                };
+        };
diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index bee9f72b3a93..024e98ef8e4d 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -27,4 +27,17 @@ config DRM_PANEL_S6E8AA0
         select DRM_MIPI_DSI
         select VIDEOMODE_HELPERS
 
+config DRM_PANEL_SHARP_LQ101R1SX01
+        tristate "Sharp LQ101R1SX01 panel"
+        depends on OF
+        depends on DRM_MIPI_DSI
+        help
+          Say Y here if you want to enable support for Sharp LQ101R1SX01
+          TFT-LCD modules. The panel has a 2560x1600 resolution and uses
+          24 bit RGB per pixel. It provides a dual MIPI DSI interface to
+          the host and has a built-in LED backlight.
+
+          To compile this driver as a module, choose M here: the module
+          will be called panel-sharp-lq101r1sx01.
+
 endmenu
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 8b929212fad7..4b2a0430804b 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -1,3 +1,4 @@
 obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o
 obj-$(CONFIG_DRM_PANEL_LD9040) += panel-ld9040.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-sharp-lq101r1sx01.c b/drivers/gpu/drm/panel/panel-sharp-lq101r1sx01.c
new file mode 100644
index 000000000000..9d81759d82fc
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-sharp-lq101r1sx01.c
@@ -0,0 +1,464 @@
+/*
+ * Copyright (C) 2014 NVIDIA Corporation
+ *
+ * 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 <linux/backlight.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_panel.h>
+
+#include <video/mipi_display.h>
+
+#include <linux/host1x.h>
+
+struct sharp_panel {
+        struct drm_panel base;
+        /* the datasheet refers to them as DSI-LINK1 and DSI-LINK2 */
+        struct mipi_dsi_device *link1;
+        struct mipi_dsi_device *link2;
+
+        struct backlight_device *backlight;
+        struct regulator *supply;
+
+        bool prepared;
+        bool enabled;
+
+        const struct drm_display_mode *mode;
+};
+
+static inline struct sharp_panel *to_sharp_panel(struct drm_panel *panel)
+{
+        return container_of(panel, struct sharp_panel, base);
+}
+
+static int sharp_panel_write(struct sharp_panel *sharp, u16 offset, u8 value)
+{
+        u8 payload[3] = { offset >> 8, offset & 0xff, value };
+        struct mipi_dsi_device *dsi = sharp->link1;
+        ssize_t err;
+
+        err = mipi_dsi_generic_write(dsi, payload, sizeof(payload));
+        if (err < 0) {
+                dev_err(&dsi->dev, "failed to write %02x to %04x: %zd\n",
+                        value, offset, err);
+                return err;
+        }
+
+        err = mipi_dsi_dcs_nop(dsi);
+        if (err < 0) {
+                dev_err(&dsi->dev, "failed to send DCS nop: %zd\n", err);
+                return err;
+        }
+
+        usleep_range(10, 20);
+
+        return 0;
+}
+
+static __maybe_unused int sharp_panel_read(struct sharp_panel *sharp,
+                                           u16 offset, u8 *value)
+{
+        ssize_t err;
+
+        cpu_to_be16s(&offset);
+
+        err = mipi_dsi_generic_read(sharp->link1, &offset, sizeof(offset),
+                                    value, sizeof(*value));
+        if (err < 0)
+                dev_err(&sharp->link1->dev, "failed to read from %04x: %zd\n",
+                        offset, err);
+
+        return err;
+}
+
+static int sharp_panel_disable(struct drm_panel *panel)
+{
+        struct sharp_panel *sharp = to_sharp_panel(panel);
+
+        if (!sharp->enabled)
+                return 0;
+
+        if (sharp->backlight) {
+                sharp->backlight->props.power = FB_BLANK_POWERDOWN;
+                backlight_update_status(sharp->backlight);
+        }
+
+        sharp->enabled = false;
+
+        return 0;
+}
+
+static int sharp_panel_unprepare(struct drm_panel *panel)
+{
+        struct sharp_panel *sharp = to_sharp_panel(panel);
+        int err;
+
+        if (!sharp->prepared)
+                return 0;
+
+        err = mipi_dsi_dcs_set_display_off(sharp->link1);
+        if (err < 0)
+                dev_err(panel->dev, "failed to set display off: %d\n", err);
+
+        err = mipi_dsi_dcs_enter_sleep_mode(sharp->link1);
+        if (err < 0)
+                dev_err(panel->dev, "failed to enter sleep mode: %d\n", err);
+
+        msleep(120);
+
+        regulator_disable(sharp->supply);
+
+        sharp->prepared = false;
+
+        return 0;
+}
+
+static int sharp_setup_symmetrical_split(struct mipi_dsi_device *left,
+                                         struct mipi_dsi_device *right,
+                                         const struct drm_display_mode *mode)
+{
+        int err;
+
+        err = mipi_dsi_dcs_set_column_address(left, 0, mode->hdisplay / 2 - 1);
+        if (err < 0) {
+                dev_err(&left->dev, "failed to set column address: %d\n", err);
+                return err;
+        }
+
+        err = mipi_dsi_dcs_set_page_address(left, 0, mode->vdisplay - 1);
+        if (err < 0) {
+                dev_err(&left->dev, "failed to set page address: %d\n", err);
+                return err;
+        }
+
+        err = mipi_dsi_dcs_set_column_address(right, mode->hdisplay / 2,
+                                              mode->hdisplay - 1);
+        if (err < 0) {
+                dev_err(&right->dev, "failed to set column address: %d\n", err);
+                return err;
+        }
+
+        err = mipi_dsi_dcs_set_page_address(right, 0, mode->vdisplay - 1);
+        if (err < 0) {
+                dev_err(&right->dev, "failed to set page address: %d\n", err);
+                return err;
+        }
+
+        return 0;
+}
+
+static int sharp_panel_prepare(struct drm_panel *panel)
+{
+        struct sharp_panel *sharp = to_sharp_panel(panel);
+        u8 format = MIPI_DCS_PIXEL_FMT_24BIT;
+        int err;
+
+        if (sharp->prepared)
+                return 0;
+
+        err = regulator_enable(sharp->supply);
+        if (err < 0)
+                return err;
+
+        usleep_range(10000, 20000);
+
+        err = mipi_dsi_dcs_soft_reset(sharp->link1);
+        if (err < 0) {
+                dev_err(panel->dev, "soft reset failed: %d\n", err);
+                goto poweroff;
+        }
+
+        msleep(120);
+
+        err = mipi_dsi_dcs_exit_sleep_mode(sharp->link1);
+        if (err < 0) {
+                dev_err(panel->dev, "failed to exit sleep mode: %d\n", err);
+                goto poweroff;
+        }
+
+        /*
+         * The MIPI DCS specification mandates this delay only between the
+         * exit_sleep_mode and enter_sleep_mode commands, so it isn't strictly
+         * necessary here.
+         */
+        /*
+        msleep(120);
+        */
+
+        /* set left-right mode */
+        err = sharp_panel_write(sharp, 0x1000, 0x2a);
+        if (err < 0) {
+                dev_err(panel->dev, "failed to set left-right mode: %d\n", err);
+                goto poweroff;
+        }
+
+        /* enable command mode */
+        err = sharp_panel_write(sharp, 0x1001, 0x01);
+        if (err < 0) {
+                dev_err(panel->dev, "failed to enable command mode: %d\n", err);
+                goto poweroff;
+        }
+
+        err = mipi_dsi_dcs_set_pixel_format(sharp->link1, format);
+        if (err < 0) {
+                dev_err(panel->dev, "failed to set pixel format: %d\n", err);
+                goto poweroff;
+        }
+
+        /*
+         * TODO: The device supports both left-right and even-odd split
+         * configurations, but this driver currently supports only the left-
+         * right split. To support a different mode a mechanism needs to be
+         * put in place to communicate the configuration back to the DSI host
+         * controller.
+         */
+        err = sharp_setup_symmetrical_split(sharp->link1, sharp->link2,
+                                            sharp->mode);
+        if (err < 0) {
+                dev_err(panel->dev, "failed to set up symmetrical split: %d\n",
+                        err);
+                goto poweroff;
+        }
+
+        err = mipi_dsi_dcs_set_display_on(sharp->link1);
+        if (err < 0) {
+                dev_err(panel->dev, "failed to set display on: %d\n", err);
+                goto poweroff;
+        }
+
+        sharp->prepared = true;
+
+        return 0;
+
+poweroff:
+        regulator_disable(sharp->supply);
+        return err;
+}
+
+static int sharp_panel_enable(struct drm_panel *panel)
+{
+        struct sharp_panel *sharp = to_sharp_panel(panel);
+
+        if (sharp->enabled)
+                return 0;
+
+        if (sharp->backlight) {
+                sharp->backlight->props.power = FB_BLANK_UNBLANK;
+                backlight_update_status(sharp->backlight);
+        }
+
+        sharp->enabled = true;
+
+        return 0;
+}
+
+static const struct drm_display_mode default_mode = {
+        .clock = 278000,
+        .hdisplay = 2560,
+        .hsync_start = 2560 + 128,
+        .hsync_end = 2560 + 128 + 64,
+        .htotal = 2560 + 128 + 64 + 64,
+        .vdisplay = 1600,
+        .vsync_start = 1600 + 4,
+        .vsync_end = 1600 + 4 + 8,
+        .vtotal = 1600 + 4 + 8 + 32,
+        .vrefresh = 60,
+};
+
+static int sharp_panel_get_modes(struct drm_panel *panel)
+{
+        struct drm_display_mode *mode;
+
+        mode = drm_mode_duplicate(panel->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);
+
+        drm_mode_probed_add(panel->connector, mode);
+
+        panel->connector->display_info.width_mm = 217;
+        panel->connector->display_info.height_mm = 136;
+
+        return 1;
+}
+
+static const struct drm_panel_funcs sharp_panel_funcs = {
+        .disable = sharp_panel_disable,
+        .unprepare = sharp_panel_unprepare,
+        .prepare = sharp_panel_prepare,
+        .enable = sharp_panel_enable,
+        .get_modes = sharp_panel_get_modes,
+};
+
+static const struct of_device_id sharp_of_match[] = {
+        { .compatible = "sharp,lq101r1sx01", },
+        { }
+};
+MODULE_DEVICE_TABLE(of, sharp_of_match);
+
+static int sharp_panel_add(struct sharp_panel *sharp)
+{
+        struct device_node *np;
+        int err;
+
+        sharp->mode = &default_mode;
+
+        sharp->supply = devm_regulator_get(&sharp->link1->dev, "power");
+        if (IS_ERR(sharp->supply))
+                return PTR_ERR(sharp->supply);
+
+        np = of_parse_phandle(sharp->link1->dev.of_node, "backlight", 0);
+        if (np) {
+                sharp->backlight = of_find_backlight_by_node(np);
+                of_node_put(np);
+
+                if (!sharp->backlight)
+                        return -EPROBE_DEFER;
+        }
+
+        drm_panel_init(&sharp->base);
+        sharp->base.funcs = &sharp_panel_funcs;
+        sharp->base.dev = &sharp->link1->dev;
+
+        err = drm_panel_add(&sharp->base);
+        if (err < 0)
+                goto put_backlight;
+
+        return 0;
+
+put_backlight:
+        if (sharp->backlight)
+                put_device(&sharp->backlight->dev);
+
+        return err;
+}
+
+static void sharp_panel_del(struct sharp_panel *sharp)
+{
+        if (sharp->base.dev)
+                drm_panel_remove(&sharp->base);
+
+        if (sharp->backlight)
+                put_device(&sharp->backlight->dev);
+
+        if (sharp->link2)
+                put_device(&sharp->link2->dev);
+}
+
+static int sharp_panel_probe(struct mipi_dsi_device *dsi)
+{
+        struct mipi_dsi_device *secondary = NULL;
+        struct sharp_panel *sharp;
+        struct device_node *np;
+        int err;
+
+        dsi->lanes = 4;
+        dsi->format = MIPI_DSI_FMT_RGB888;
+        dsi->mode_flags = MIPI_DSI_MODE_LPM;
+
+        /* Find DSI-LINK1 */
+        np = of_parse_phandle(dsi->dev.of_node, "link2", 0);
+        if (np) {
+                secondary = of_find_mipi_dsi_device_by_node(np);
+                of_node_put(np);
+
+                if (!secondary)
+                        return -EPROBE_DEFER;
+        }
+
+        /* register a panel for only the DSI-LINK1 interface */
+        if (secondary) {
+                sharp = devm_kzalloc(&dsi->dev, sizeof(*sharp), GFP_KERNEL);
+                if (!sharp) {
+                        put_device(&secondary->dev);
+                        return -ENOMEM;
+                }
+
+                mipi_dsi_set_drvdata(dsi, sharp);
+
+                sharp->link2 = secondary;
+                sharp->link1 = dsi;
+
+                err = sharp_panel_add(sharp);
+                if (err < 0) {
+                        put_device(&secondary->dev);
+                        return err;
+                }
+        }
+
+        err = mipi_dsi_attach(dsi);
+        if (err < 0) {
+                if (secondary)
+                        sharp_panel_del(sharp);
+
+                return err;
+        }
+
+        return 0;
+}
+
+static int sharp_panel_remove(struct mipi_dsi_device *dsi)
+{
+        struct sharp_panel *sharp = mipi_dsi_get_drvdata(dsi);
+        int err;
+
+        /* only detach from host for the DSI-LINK2 interface */
+        if (!sharp) {
+                mipi_dsi_detach(dsi);
+                return 0;
+        }
+
+        err = sharp_panel_disable(&sharp->base);
+        if (err < 0)
+                dev_err(&dsi->dev, "failed to disable panel: %d\n", err);
+
+        err = mipi_dsi_detach(dsi);
+        if (err < 0)
+                dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", err);
+
+        drm_panel_detach(&sharp->base);
+        sharp_panel_del(sharp);
+
+        return 0;
+}
+
+static void sharp_panel_shutdown(struct mipi_dsi_device *dsi)
+{
+        struct sharp_panel *sharp = mipi_dsi_get_drvdata(dsi);
+
+        /* nothing to do for DSI-LINK2 */
+        if (!sharp)
+                return;
+
+        sharp_panel_disable(&sharp->base);
+}
+
+static struct mipi_dsi_driver sharp_panel_driver = {
+        .driver = {
+                .name = "panel-sharp-lq101r1sx01",
+                .of_match_table = sharp_of_match,
+        },
+        .probe = sharp_panel_probe,
+        .remove = sharp_panel_remove,
+        .shutdown = sharp_panel_shutdown,
+};
+module_mipi_dsi_driver(sharp_panel_driver);
+
+MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
+MODULE_DESCRIPTION("Sharp LQ101R1SX01 panel driver");
+MODULE_LICENSE("GPL v2");