staging: drm/imx: Add parallel display support

This adds support for parallel displays for i.MX. It consists
of a drm encoder/connector pair which eventually passes EDID
data from the devicetree to the drm core.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/imx-drm/Kconfig

@@ -15,3 +15,7 @@ config DRM_IMX_FB_HELPER
 	  The DRM framework can provide a legacy /dev/fb0 framebuffer
 	  for your device. This is necessary to get a framebuffer console
 	  and also for appplications using the legacy framebuffer API
+
+config DRM_IMX_PARALLEL_DISPLAY
+	tristate "Support for parallel displays"
+	depends on DRM_IMX

drivers/staging/imx-drm/Makefile

@@ -3,4 +3,5 @@ imxdrm-objs := imx-drm-core.o imx-fb.o
 
 obj-$(CONFIG_DRM_IMX) += imxdrm.o
 
+obj-$(CONFIG_DRM_IMX_PARALLEL_DISPLAY) += parallel-display.o
 obj-$(CONFIG_DRM_IMX_FB_HELPER) += imx-fbdev.o

drivers/staging/imx-drm/parallel-display.c

+/*
+ * i.MX drm driver - parallel display implementation
+ *
+ * Copyright (C) 2012 Sascha Hauer, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <linux/module.h>
+#include <drm/drmP.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <linux/videodev2.h>
+
+#include "imx-drm.h"
+
+#define con_to_imxpd(x) container_of(x, struct imx_parallel_display, connector)
+#define enc_to_imxpd(x) container_of(x, struct imx_parallel_display, encoder)
+
+struct imx_parallel_display {
+	struct drm_connector connector;
+	struct imx_drm_connector *imx_drm_connector;
+	struct drm_encoder encoder;
+	struct imx_drm_encoder *imx_drm_encoder;
+	struct device *dev;
+	void *edid;
+	int edid_len;
+	u32 interface_pix_fmt;
+	int mode_valid;
+	struct drm_display_mode mode;
+};
+
+static enum drm_connector_status imx_pd_connector_detect(
+		struct drm_connector *connector, bool force)
+{
+	return connector_status_connected;
+}
+
+static void imx_pd_connector_destroy(struct drm_connector *connector)
+{
+	/* do not free here */
+}
+
+static int imx_pd_connector_get_modes(struct drm_connector *connector)
+{
+	struct imx_parallel_display *imxpd = con_to_imxpd(connector);
+	int num_modes = 0;
+
+	if (imxpd->edid) {
+		drm_mode_connector_update_edid_property(connector, imxpd->edid);
+		num_modes = drm_add_edid_modes(connector, imxpd->edid);
+	}
+
+	if (imxpd->mode_valid) {
+		struct drm_display_mode *mode = drm_mode_create(connector->dev);
+		drm_mode_copy(mode, &imxpd->mode);
+		mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+		drm_mode_probed_add(connector, mode);
+		num_modes++;
+	}
+
+	return num_modes;
+}
+
+static int imx_pd_connector_mode_valid(struct drm_connector *connector,
+			  struct drm_display_mode *mode)
+{
+	return 0;
+}
+
+static struct drm_encoder *imx_pd_connector_best_encoder(
+		struct drm_connector *connector)
+{
+	struct imx_parallel_display *imxpd = con_to_imxpd(connector);
+
+	return &imxpd->encoder;
+}
+
+static void imx_pd_encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+}
+
+static bool imx_pd_encoder_mode_fixup(struct drm_encoder *encoder,
+			   const struct drm_display_mode *mode,
+			   struct drm_display_mode *adjusted_mode)
+{
+	return true;
+}
+
+static void imx_pd_encoder_prepare(struct drm_encoder *encoder)
+{
+	struct imx_parallel_display *imxpd = enc_to_imxpd(encoder);
+
+	imx_drm_crtc_panel_format(encoder->crtc, DRM_MODE_ENCODER_NONE,
+			imxpd->interface_pix_fmt);
+}
+
+static void imx_pd_encoder_commit(struct drm_encoder *encoder)
+{
+}
+
+static void imx_pd_encoder_mode_set(struct drm_encoder *encoder,
+			 struct drm_display_mode *mode,
+			 struct drm_display_mode *adjusted_mode)
+{
+}
+
+static void imx_pd_encoder_disable(struct drm_encoder *encoder)
+{
+}
+
+static void imx_pd_encoder_destroy(struct drm_encoder *encoder)
+{
+	/* do not free here */
+}
+
+static struct drm_connector_funcs imx_pd_connector_funcs = {
+	.dpms = drm_helper_connector_dpms,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = imx_pd_connector_detect,
+	.destroy = imx_pd_connector_destroy,
+};
+
+static struct drm_connector_helper_funcs imx_pd_connector_helper_funcs = {
+	.get_modes = imx_pd_connector_get_modes,
+	.best_encoder = imx_pd_connector_best_encoder,
+	.mode_valid = imx_pd_connector_mode_valid,
+};
+
+static struct drm_encoder_funcs imx_pd_encoder_funcs = {
+	.destroy = imx_pd_encoder_destroy,
+};
+
+static struct drm_encoder_helper_funcs imx_pd_encoder_helper_funcs = {
+	.dpms = imx_pd_encoder_dpms,
+	.mode_fixup = imx_pd_encoder_mode_fixup,
+	.prepare = imx_pd_encoder_prepare,
+	.commit = imx_pd_encoder_commit,
+	.mode_set = imx_pd_encoder_mode_set,
+	.disable = imx_pd_encoder_disable,
+};
+
+static int imx_pd_register(struct imx_parallel_display *imxpd)
+{
+	int ret;
+
+	drm_mode_connector_attach_encoder(&imxpd->connector, &imxpd->encoder);
+
+	imxpd->connector.funcs = &imx_pd_connector_funcs;
+	imxpd->encoder.funcs = &imx_pd_encoder_funcs;
+
+	imxpd->encoder.encoder_type = DRM_MODE_ENCODER_NONE;
+	imxpd->connector.connector_type = DRM_MODE_CONNECTOR_VGA;
+
+	drm_encoder_helper_add(&imxpd->encoder, &imx_pd_encoder_helper_funcs);
+	ret = imx_drm_add_encoder(&imxpd->encoder, &imxpd->imx_drm_encoder,
+			THIS_MODULE);
+	if (ret) {
+		dev_err(imxpd->dev, "adding encoder failed with %d\n", ret);
+		return ret;
+	}
+
+	drm_connector_helper_add(&imxpd->connector,
+			&imx_pd_connector_helper_funcs);
+
+	ret = imx_drm_add_connector(&imxpd->connector,
+			&imxpd->imx_drm_connector, THIS_MODULE);
+	if (ret) {
+		imx_drm_remove_encoder(imxpd->imx_drm_encoder);
+		dev_err(imxpd->dev, "adding connector failed with %d\n", ret);
+		return ret;
+	}
+
+	imxpd->connector.encoder = &imxpd->encoder;
+
+	return 0;
+}
+
+static int __devinit imx_pd_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	const u8 *edidp;
+	struct imx_parallel_display *imxpd;
+	int ret;
+	const char *fmt;
+
+	imxpd = devm_kzalloc(&pdev->dev, sizeof(*imxpd), GFP_KERNEL);
+	if (!imxpd)
+		return -ENOMEM;
+
+	edidp = of_get_property(np, "edid", &imxpd->edid_len);
+	if (edidp)
+		imxpd->edid = kmemdup(edidp, imxpd->edid_len, GFP_KERNEL);
+
+	ret = of_property_read_string(np, "interface-pix-fmt", &fmt);
+	if (!ret) {
+		if (!strcmp(fmt, "rgb24"))
+			imxpd->interface_pix_fmt = V4L2_PIX_FMT_RGB24;
+		else if (!strcmp(fmt, "rgb565"))
+			imxpd->interface_pix_fmt = V4L2_PIX_FMT_RGB565;
+	}
+
+	imxpd->dev = &pdev->dev;
+
+	ret = imx_pd_register(imxpd);
+	if (ret)
+		return ret;
+
+	ret = imx_drm_encoder_add_possible_crtcs(imxpd->imx_drm_encoder, np);
+
+	platform_set_drvdata(pdev, imxpd);
+
+	return 0;
+}
+
+static int __devexit imx_pd_remove(struct platform_device *pdev)
+{
+	struct imx_parallel_display *imxpd = platform_get_drvdata(pdev);
+	struct drm_connector *connector = &imxpd->connector;
+	struct drm_encoder *encoder = &imxpd->encoder;
+
+	drm_mode_connector_detach_encoder(connector, encoder);
+
+	imx_drm_remove_connector(imxpd->imx_drm_connector);
+	imx_drm_remove_encoder(imxpd->imx_drm_encoder);
+
+	return 0;
+}
+
+static const struct of_device_id imx_pd_dt_ids[] = {
+	{ .compatible = "fsl,imx-parallel-display", },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver imx_pd_driver = {
+	.probe		= imx_pd_probe,
+	.remove		= __devexit_p(imx_pd_remove),
+	.driver		= {
+		.of_match_table = imx_pd_dt_ids,
+		.name	= "imx-parallel-display",
+		.owner	= THIS_MODULE,
+	},
+};
+
+module_platform_driver(imx_pd_driver);
+
+MODULE_DESCRIPTION("i.MX parallel display driver");
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_LICENSE("GPL");