drm/tilcdc: add support for LCD panels (v5)

Add an output panel driver for LCD panels.  Tested with LCD3 cape on
beaglebone.

v1: original
v2: s/of_find_node_by_name()/of_get_child_by_name()/ from Pantelis
    Antoniou
v3: add backlight support
v4: rebase to latest of video timing helpers
v5: remove some unneeded fields from panel-info struct, add DT bindings
    docs

Signed-off-by: Rob Clark <robdclark@gmail.com>
Tested-by: Koen Kooi <koen@dominion.thruhere.net>

5 files changed, 469 insertions, 0 deletions

diff --git a/drivers/gpu/drm/tilcdc/Kconfig b/drivers/gpu/drm/tilcdc/Kconfig
index ee9b592d59eb..ae14fd6ea924 100644
--- a/drivers/gpu/drm/tilcdc/Kconfig
+++ b/drivers/gpu/drm/tilcdc/Kconfig
@@ -4,6 +4,9 @@ config DRM_TILCDC
         select DRM_KMS_HELPER
         select DRM_KMS_CMA_HELPER
         select DRM_GEM_CMA_HELPER
+        select OF_VIDEOMODE
+        select OF_DISPLAY_TIMING
+        select BACKLIGHT_CLASS_DEVICE
         help
           Choose this option if you have an TI SoC with LCDC display
           controller, for example AM33xx in beagle-bone, DA8xx, or
diff --git a/drivers/gpu/drm/tilcdc/Makefile b/drivers/gpu/drm/tilcdc/Makefile
index aa9097edbaf8..deda656b10e7 100644
--- a/drivers/gpu/drm/tilcdc/Makefile
+++ b/drivers/gpu/drm/tilcdc/Makefile
@@ -4,6 +4,7 @@ tilcdc-y := \
         tilcdc_crtc.o \
         tilcdc_tfp410.o \
         tilcdc_slave.o \
+        tilcdc_panel.o \
         tilcdc_drv.o
 
 obj-$(CONFIG_DRM_TILCDC)        += tilcdc.o
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index 25f3add2a754..c5b592dc1970 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -21,6 +21,7 @@
 #include "tilcdc_regs.h"
 #include "tilcdc_tfp410.h"
 #include "tilcdc_slave.h"
+#include "tilcdc_panel.h"
 
 #include "drm_fb_helper.h"
 
@@ -589,6 +590,7 @@ static int __init tilcdc_drm_init(void)
         DBG("init");
         tilcdc_tfp410_init();
         tilcdc_slave_init();
+        tilcdc_panel_init();
         return platform_driver_register(&tilcdc_platform_driver);
 }
 
@@ -597,6 +599,7 @@ static void __exit tilcdc_drm_fini(void)
         DBG("fini");
         tilcdc_tfp410_fini();
         tilcdc_slave_fini();
+        tilcdc_panel_fini();
         platform_driver_unregister(&tilcdc_platform_driver);
 }
 
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_panel.c b/drivers/gpu/drm/tilcdc/tilcdc_panel.c
new file mode 100644
index 000000000000..580b74e2022b
--- /dev/null
+++ b/drivers/gpu/drm/tilcdc/tilcdc_panel.c
@@ -0,0 +1,436 @@
+/*
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Rob Clark <robdclark@gmail.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.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/backlight.h>
+#include <video/display_timing.h>
+#include <video/of_display_timing.h>
+#include <video/videomode.h>
+
+#include "tilcdc_drv.h"
+
+struct panel_module {
+        struct tilcdc_module base;
+        struct tilcdc_panel_info *info;
+        struct display_timings *timings;
+        struct backlight_device *backlight;
+};
+#define to_panel_module(x) container_of(x, struct panel_module, base)
+
+
+/*
+ * Encoder:
+ */
+
+struct panel_encoder {
+        struct drm_encoder base;
+        struct panel_module *mod;
+};
+#define to_panel_encoder(x) container_of(x, struct panel_encoder, base)
+
+
+static void panel_encoder_destroy(struct drm_encoder *encoder)
+{
+        struct panel_encoder *panel_encoder = to_panel_encoder(encoder);
+        drm_encoder_cleanup(encoder);
+        kfree(panel_encoder);
+}
+
+static void panel_encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+        struct panel_encoder *panel_encoder = to_panel_encoder(encoder);
+        struct backlight_device *backlight = panel_encoder->mod->backlight;
+
+        if (!backlight)
+                return;
+
+        backlight->props.power = mode == DRM_MODE_DPMS_ON
+                                     ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
+        backlight_update_status(backlight);
+}
+
+static bool panel_encoder_mode_fixup(struct drm_encoder *encoder,
+                const struct drm_display_mode *mode,
+                struct drm_display_mode *adjusted_mode)
+{
+        /* nothing needed */
+        return true;
+}
+
+static void panel_encoder_prepare(struct drm_encoder *encoder)
+{
+        struct panel_encoder *panel_encoder = to_panel_encoder(encoder);
+        panel_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
+        tilcdc_crtc_set_panel_info(encoder->crtc, panel_encoder->mod->info);
+}
+
+static void panel_encoder_commit(struct drm_encoder *encoder)
+{
+        panel_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
+}
+
+static void panel_encoder_mode_set(struct drm_encoder *encoder,
+                struct drm_display_mode *mode,
+                struct drm_display_mode *adjusted_mode)
+{
+        /* nothing needed */
+}
+
+static const struct drm_encoder_funcs panel_encoder_funcs = {
+                .destroy        = panel_encoder_destroy,
+};
+
+static const struct drm_encoder_helper_funcs panel_encoder_helper_funcs = {
+                .dpms           = panel_encoder_dpms,
+                .mode_fixup     = panel_encoder_mode_fixup,
+                .prepare        = panel_encoder_prepare,
+                .commit         = panel_encoder_commit,
+                .mode_set       = panel_encoder_mode_set,
+};
+
+static struct drm_encoder *panel_encoder_create(struct drm_device *dev,
+                struct panel_module *mod)
+{
+        struct panel_encoder *panel_encoder;
+        struct drm_encoder *encoder;
+        int ret;
+
+        panel_encoder = kzalloc(sizeof(*panel_encoder), GFP_KERNEL);
+        if (!panel_encoder) {
+                dev_err(dev->dev, "allocation failed\n");
+                return NULL;
+        }
+
+        panel_encoder->mod = mod;
+
+        encoder = &panel_encoder->base;
+        encoder->possible_crtcs = 1;
+
+        ret = drm_encoder_init(dev, encoder, &panel_encoder_funcs,
+                        DRM_MODE_ENCODER_LVDS);
+        if (ret < 0)
+                goto fail;
+
+        drm_encoder_helper_add(encoder, &panel_encoder_helper_funcs);
+
+        return encoder;
+
+fail:
+        panel_encoder_destroy(encoder);
+        return NULL;
+}
+
+/*
+ * Connector:
+ */
+
+struct panel_connector {
+        struct drm_connector base;
+
+        struct drm_encoder *encoder;  /* our connected encoder */
+        struct panel_module *mod;
+};
+#define to_panel_connector(x) container_of(x, struct panel_connector, base)
+
+
+static void panel_connector_destroy(struct drm_connector *connector)
+{
+        struct panel_connector *panel_connector = to_panel_connector(connector);
+        drm_connector_cleanup(connector);
+        kfree(panel_connector);
+}
+
+static enum drm_connector_status panel_connector_detect(
+                struct drm_connector *connector,
+                bool force)
+{
+        return connector_status_connected;
+}
+
+static int panel_connector_get_modes(struct drm_connector *connector)
+{
+        struct drm_device *dev = connector->dev;
+        struct panel_connector *panel_connector = to_panel_connector(connector);
+        struct display_timings *timings = panel_connector->mod->timings;
+        int i;
+
+        for (i = 0; i < timings->num_timings; i++) {
+                struct drm_display_mode *mode = drm_mode_create(dev);
+                struct videomode vm;
+
+                if (videomode_from_timing(timings, &vm, i))
+                        break;
+
+                drm_display_mode_from_videomode(&vm, mode);
+
+                mode->type = DRM_MODE_TYPE_DRIVER;
+
+                if (timings->native_mode == i)
+                        mode->type |= DRM_MODE_TYPE_PREFERRED;
+
+                drm_mode_set_name(mode);
+                drm_mode_probed_add(connector, mode);
+        }
+
+        return i;
+}
+
+static int panel_connector_mode_valid(struct drm_connector *connector,
+                  struct drm_display_mode *mode)
+{
+        struct tilcdc_drm_private *priv = connector->dev->dev_private;
+        /* our only constraints are what the crtc can generate: */
+        return tilcdc_crtc_mode_valid(priv->crtc, mode);
+}
+
+static struct drm_encoder *panel_connector_best_encoder(
+                struct drm_connector *connector)
+{
+        struct panel_connector *panel_connector = to_panel_connector(connector);
+        return panel_connector->encoder;
+}
+
+static const struct drm_connector_funcs panel_connector_funcs = {
+        .destroy            = panel_connector_destroy,
+        .dpms               = drm_helper_connector_dpms,
+        .detect             = panel_connector_detect,
+        .fill_modes         = drm_helper_probe_single_connector_modes,
+};
+
+static const struct drm_connector_helper_funcs panel_connector_helper_funcs = {
+        .get_modes          = panel_connector_get_modes,
+        .mode_valid         = panel_connector_mode_valid,
+        .best_encoder       = panel_connector_best_encoder,
+};
+
+static struct drm_connector *panel_connector_create(struct drm_device *dev,
+                struct panel_module *mod, struct drm_encoder *encoder)
+{
+        struct panel_connector *panel_connector;
+        struct drm_connector *connector;
+        int ret;
+
+        panel_connector = kzalloc(sizeof(*panel_connector), GFP_KERNEL);
+        if (!panel_connector) {
+                dev_err(dev->dev, "allocation failed\n");
+                return NULL;
+        }
+
+        panel_connector->encoder = encoder;
+        panel_connector->mod = mod;
+
+        connector = &panel_connector->base;
+
+        drm_connector_init(dev, connector, &panel_connector_funcs,
+                        DRM_MODE_CONNECTOR_LVDS);
+        drm_connector_helper_add(connector, &panel_connector_helper_funcs);
+
+        connector->interlace_allowed = 0;
+        connector->doublescan_allowed = 0;
+
+        ret = drm_mode_connector_attach_encoder(connector, encoder);
+        if (ret)
+                goto fail;
+
+        drm_sysfs_connector_add(connector);
+
+        return connector;
+
+fail:
+        panel_connector_destroy(connector);
+        return NULL;
+}
+
+/*
+ * Module:
+ */
+
+static int panel_modeset_init(struct tilcdc_module *mod, struct drm_device *dev)
+{
+        struct panel_module *panel_mod = to_panel_module(mod);
+        struct tilcdc_drm_private *priv = dev->dev_private;
+        struct drm_encoder *encoder;
+        struct drm_connector *connector;
+
+        encoder = panel_encoder_create(dev, panel_mod);
+        if (!encoder)
+                return -ENOMEM;
+
+        connector = panel_connector_create(dev, panel_mod, encoder);
+        if (!connector)
+                return -ENOMEM;
+
+        priv->encoders[priv->num_encoders++] = encoder;
+        priv->connectors[priv->num_connectors++] = connector;
+
+        return 0;
+}
+
+static void panel_destroy(struct tilcdc_module *mod)
+{
+        struct panel_module *panel_mod = to_panel_module(mod);
+
+        if (panel_mod->timings) {
+                display_timings_release(panel_mod->timings);
+                kfree(panel_mod->timings);
+        }
+
+        tilcdc_module_cleanup(mod);
+        kfree(panel_mod->info);
+        kfree(panel_mod);
+}
+
+static const struct tilcdc_module_ops panel_module_ops = {
+                .modeset_init = panel_modeset_init,
+                .destroy = panel_destroy,
+};
+
+/*
+ * Device:
+ */
+
+/* maybe move this somewhere common if it is needed by other outputs? */
+static struct tilcdc_panel_info * of_get_panel_info(struct device_node *np)
+{
+        struct device_node *info_np;
+        struct tilcdc_panel_info *info;
+        int ret = 0;
+
+        if (!np) {
+                pr_err("%s: no devicenode given\n", __func__);
+                return NULL;
+        }
+
+        info_np = of_get_child_by_name(np, "panel-info");
+        if (!info_np) {
+                pr_err("%s: could not find panel-info node\n", __func__);
+                return NULL;
+        }
+
+        info = kzalloc(sizeof(*info), GFP_KERNEL);
+        if (!info) {
+                pr_err("%s: allocation failed\n", __func__);
+                return NULL;
+        }
+
+        ret |= of_property_read_u32(info_np, "ac-bias", &info->ac_bias);
+        ret |= of_property_read_u32(info_np, "ac-bias-intrpt", &info->ac_bias_intrpt);
+        ret |= of_property_read_u32(info_np, "dma-burst-sz", &info->dma_burst_sz);
+        ret |= of_property_read_u32(info_np, "bpp", &info->bpp);
+        ret |= of_property_read_u32(info_np, "fdd", &info->fdd);
+        ret |= of_property_read_u32(info_np, "sync-edge", &info->sync_edge);
+        ret |= of_property_read_u32(info_np, "sync-ctrl", &info->sync_ctrl);
+        ret |= of_property_read_u32(info_np, "raster-order", &info->raster_order);
+        ret |= of_property_read_u32(info_np, "fifo-th", &info->fifo_th);
+
+        /* optional: */
+        info->tft_alt_mode      = of_property_read_bool(info_np, "tft-alt-mode");
+        info->invert_pxl_clk    = of_property_read_bool(info_np, "invert-pxl-clk");
+
+        if (ret) {
+                pr_err("%s: error reading panel-info properties\n", __func__);
+                kfree(info);
+                return NULL;
+        }
+
+        return info;
+}
+
+static struct of_device_id panel_of_match[];
+
+static int panel_probe(struct platform_device *pdev)
+{
+        struct device_node *node = pdev->dev.of_node;
+        struct panel_module *panel_mod;
+        struct tilcdc_module *mod;
+        struct pinctrl *pinctrl;
+        int ret = -EINVAL;
+
+
+        /* bail out early if no DT data: */
+        if (!node) {
+                dev_err(&pdev->dev, "device-tree data is missing\n");
+                return -ENXIO;
+        }
+
+        panel_mod = kzalloc(sizeof(*panel_mod), GFP_KERNEL);
+        if (!panel_mod)
+                return -ENOMEM;
+
+        mod = &panel_mod->base;
+
+        tilcdc_module_init(mod, "panel", &panel_module_ops);
+
+        pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
+        if (IS_ERR(pinctrl))
+                dev_warn(&pdev->dev, "pins are not configured\n");
+
+
+        panel_mod->timings = of_get_display_timings(node);
+        if (!panel_mod->timings) {
+                dev_err(&pdev->dev, "could not get panel timings\n");
+                goto fail;
+        }
+
+        panel_mod->info = of_get_panel_info(node);
+        if (!panel_mod->info) {
+                dev_err(&pdev->dev, "could not get panel info\n");
+                goto fail;
+        }
+
+        panel_mod->backlight = of_find_backlight_by_node(node);
+        if (panel_mod->backlight)
+                dev_info(&pdev->dev, "found backlight\n");
+
+        return 0;
+
+fail:
+        panel_destroy(mod);
+        return ret;
+}
+
+static int panel_remove(struct platform_device *pdev)
+{
+        return 0;
+}
+
+static struct of_device_id panel_of_match[] = {
+                { .compatible = "ti,tilcdc,panel", },
+                { },
+};
+MODULE_DEVICE_TABLE(of, panel_of_match);
+
+struct platform_driver panel_driver = {
+        .probe = panel_probe,
+        .remove = panel_remove,
+        .driver = {
+                .owner = THIS_MODULE,
+                .name = "panel",
+                .of_match_table = panel_of_match,
+        },
+};
+
+int __init tilcdc_panel_init(void)
+{
+        return platform_driver_register(&panel_driver);
+}
+
+void __exit tilcdc_panel_fini(void)
+{
+        platform_driver_unregister(&panel_driver);
+}
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_panel.h b/drivers/gpu/drm/tilcdc/tilcdc_panel.h
new file mode 100644
index 000000000000..7db40aacc74a
--- /dev/null
+++ b/drivers/gpu/drm/tilcdc/tilcdc_panel.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Rob Clark <robdclark@gmail.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.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __TILCDC_PANEL_H__
+#define __TILCDC_PANEL_H__
+
+/* sub-module for generic lcd panel output */
+
+int tilcdc_panel_init(void);
+void tilcdc_panel_fini(void);
+
+#endif /* __TILCDC_PANEL_H__ */