[PATCH 2/4] RFC: drm/lcdc: add support for LCD panels (v2)

[Rob Clark <robdclark@gmail.com>]

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

TODO: need some way to control the appropriate backlight device
TODO: probably want to make the DT bindings more generic for panel-info

v1: original
v2: s/of_find_node_by_name()/of_get_child_by_name()/ from Pantelis
    Antoniou

Signed-off-by: Rob Clark <robdclark@gmail.com>
---
 drivers/gpu/drm/lcdc/Kconfig      |   2 +
 drivers/gpu/drm/lcdc/Makefile     |   1 +
 drivers/gpu/drm/lcdc/lcdc_drv.c   |   3 +
 drivers/gpu/drm/lcdc/lcdc_panel.c | 458 ++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/lcdc/lcdc_panel.h |  26 +++
 5 files changed, 490 insertions(+)
 create mode 100644 drivers/gpu/drm/lcdc/lcdc_panel.c
 create mode 100644 drivers/gpu/drm/lcdc/lcdc_panel.h

diff --git a/drivers/gpu/drm/lcdc/Kconfig b/drivers/gpu/drm/lcdc/Kconfig
index 58806d4..7806184 100644
--- a/drivers/gpu/drm/lcdc/Kconfig
+++ b/drivers/gpu/drm/lcdc/Kconfig
@@ -4,6 +4,8 @@ config DRM_LCDC
 	select DRM_KMS_HELPER
 	select DRM_KMS_CMA_HELPER
 	select DRM_GEM_CMA_HELPER
+	select DISPLAY_TIMING
+	select OF_DISPLAY_TIMINGS
 	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/lcdc/Makefile b/drivers/gpu/drm/lcdc/Makefile
index db32161..27d19ce 100644
--- a/drivers/gpu/drm/lcdc/Makefile
+++ b/drivers/gpu/drm/lcdc/Makefile
@@ -3,6 +3,7 @@ ccflags-y := -Iinclude/drm -Werror
 lcdc-y := \
 	lcdc_crtc.o \
 	lcdc_tfp410.o \
+	lcdc_panel.o \
 	lcdc_drv.o
 
 obj-$(CONFIG_DRM_LCDC)	+= lcdc.o
diff --git a/drivers/gpu/drm/lcdc/lcdc_drv.c b/drivers/gpu/drm/lcdc/lcdc_drv.c
index 5e6d218..ee892cb 100644
--- a/drivers/gpu/drm/lcdc/lcdc_drv.c
+++ b/drivers/gpu/drm/lcdc/lcdc_drv.c
@@ -20,6 +20,7 @@
 #include "lcdc_drv.h"
 #include "lcdc_regs.h"
 #include "lcdc_tfp410.h"
+#include "lcdc_panel.h"
 
 #include "drm_fb_helper.h"
 
@@ -584,6 +585,7 @@ static int __init lcdc_drm_init(void)
 {
 	DBG("init");
 	lcdc_tfp410_init();
+	lcdc_panel_init();
 	return platform_driver_register(&lcdc_platform_driver);
 }
 
@@ -591,6 +593,7 @@ static void __exit lcdc_drm_fini(void)
 {
 	DBG("fini");
 	lcdc_tfp410_fini();
+	lcdc_panel_fini();
 	platform_driver_unregister(&lcdc_platform_driver);
 }
 
diff --git a/drivers/gpu/drm/lcdc/lcdc_panel.c b/drivers/gpu/drm/lcdc/lcdc_panel.c
new file mode 100644
index 0000000..037e2d2
--- /dev/null
+++ b/drivers/gpu/drm/lcdc/lcdc_panel.c
@@ -0,0 +1,458 @@
+/*
+ * 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/of_display_timings.h>
+
+#include "lcdc_drv.h"
+
+struct panel_module {
+	struct lcdc_module base;
+	struct lcdc_panel_info *info;
+	struct display_timings *timings;
+};
+#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)
+{
+}
+
+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);
+	lcdc_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;
+}
+
+/* maybe this should be helper in drm-core? */
+static inline void copy_timings_to_drm(struct drm_display_mode *mode,
+		struct display_timing *timing)
+{
+	mode->clock = timing->pixelclock.typ / 1000;
+
+	mode->hdisplay = timing->hactive.typ;
+	mode->hsync_start = mode->hdisplay + timing->hfront_porch.typ;
+	mode->hsync_end = mode->hsync_start + timing->hsync_len.typ;
+	mode->htotal = mode->hsync_end + timing->hback_porch.typ;
+
+	mode->vdisplay = timing->vactive.typ;
+	mode->vsync_start = mode->vdisplay + timing->vfront_porch.typ;
+	mode->vsync_end = mode->vsync_start + timing->vsync_len.typ;
+	mode->vtotal = mode->vsync_end + timing->vback_porch.typ;
+
+	mode->flags = 0;
+
+	if (timing->interlaced)
+		mode->flags |= DRM_MODE_FLAG_INTERLACE;
+
+	if (timing->doublescan)
+		mode->flags |= DRM_MODE_FLAG_DBLSCAN;
+
+	if (timing->hsync_pol_active)
+		mode->flags |= DRM_MODE_FLAG_PHSYNC;
+	else
+		mode->flags |= DRM_MODE_FLAG_NHSYNC;
+
+	if (timing->vsync_pol_active)
+		mode->flags |= DRM_MODE_FLAG_PVSYNC;
+	else
+		mode->flags |= DRM_MODE_FLAG_NVSYNC;
+}
+
+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);
+
+		copy_timings_to_drm(mode, display_timings_get(timings, i));
+
+		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 timings->num_timings;
+}
+
+static int panel_connector_mode_valid(struct drm_connector *connector,
+		  struct drm_display_mode *mode)
+{
+	struct lcdc_drm_private *priv = connector->dev->dev_private;
+	/* our only constraints are what the crtc can generate: */
+	return lcdc_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 lcdc_module *mod, struct drm_device *dev)
+{
+	struct panel_module *panel_mod = to_panel_module(mod);
+	struct lcdc_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 lcdc_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);
+	}
+
+	lcdc_module_cleanup(mod);
+	kfree(panel_mod->info);
+	kfree(panel_mod);
+}
+
+static const struct lcdc_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 lcdc_panel_info * of_get_panel_info(struct device_node *np)
+{
+	struct device_node *info_np;
+	struct lcdc_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->stn_565_mode      = of_property_read_bool(info_np, "stn-565-mode");
+	info->mono_8bit_mode    = of_property_read_bool(info_np, "mono-8bit-mode");
+	info->invert_line_clock = of_property_read_bool(info_np, "invert-line-clock");
+	info->invert_frm_clock  = of_property_read_bool(info_np, "invert-frm-clock");
+	info->invert_pxl_clk    = of_property_read_bool(info_np, "invert-pxl-clk");
+
+	if (of_property_read_u32(info_np, "max-bpp", &info->max_bpp))
+		info->max_bpp = info->bpp;
+	if (of_property_read_u32(info_np, "min-bpp", &info->min_bpp))
+		info->min_bpp = info->bpp;
+
+	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 __devinit panel_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct panel_module *panel_mod;
+	struct lcdc_module *mod;
+	struct pinctrl *pinctrl;
+	int ret = -EINVAL;
+
+	/* bail out early if no DT data: */
+	if (!of_match_device(panel_of_match, &pdev->dev)) {
+		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;
+
+	lcdc_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_timing_list(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;
+	}
+
+	return 0;
+
+fail:
+	panel_destroy(mod);
+	return ret;
+}
+
+static int __devexit panel_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static struct of_device_id panel_of_match[] = {
+		{ .compatible = "lcdc,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 lcdc_panel_init(void)
+{
+	return platform_driver_register(&panel_driver);
+}
+
+void __exit lcdc_panel_fini(void)
+{
+	platform_driver_unregister(&panel_driver);
+}
diff --git a/drivers/gpu/drm/lcdc/lcdc_panel.h b/drivers/gpu/drm/lcdc/lcdc_panel.h
new file mode 100644
index 0000000..44ce773
--- /dev/null
+++ b/drivers/gpu/drm/lcdc/lcdc_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 __LCDC_PANEL_H__
+#define __LCDC_PANEL_H__
+
+/* sub-module for generic lcd panel output */
+
+int lcdc_panel_init(void);
+void lcdc_panel_fini(void);
+
+#endif /* __LCDC_PANEL_H__ */
-- 
1.8.0.2