drm/tilcdc: add encoder slave (v2)

Add output panel driver for i2c encoder slaves.

v1: original
v2: add DT bindings docs, and minor updates for review comments

Signed-off-by: Rob Clark <[e-mail]>
Reviewed-by: Daniel Vetter <[e-mail]>
Tested-by: Koen Kooi <[e-mail]>

Documentation/devicetree/bindings/drm/tilcdc/slave.txt

···
+Device-Tree bindings for tilcdc DRM encoder slave output driver
+
+Required properties:
+ - compatible: value should be "ti,tilcdc,slave".
+ - i2c: the phandle for the i2c device the encoder slave is connected to
+
+Recommended properties:
+ - pinctrl-names, pinctrl-0: the pincontrol settings to configure
+   muxing properly for pins that connect to TFP410 device
+
+Example:
+
+	hdmi {
+		compatible = "ti,tilcdc,slave";
+		i2c = <&i2c0>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&nxp_hdmi_bonelt_pins>;
+	};

drivers/gpu/drm/tilcdc/Makefile

···
 tilcdc-y := \
 	tilcdc_crtc.o \
 	tilcdc_tfp410.o \
+	tilcdc_slave.o \
 	tilcdc_drv.o
 
 obj-$(CONFIG_DRM_TILCDC)	+= tilcdc.o

drivers/gpu/drm/tilcdc/tilcdc_drv.c

···
 #include "tilcdc_drv.h"
 #include "tilcdc_regs.h"
 #include "tilcdc_tfp410.h"
+#include "tilcdc_slave.h"
 
 #include "drm_fb_helper.h"
 
···
 {
 	DBG("init");
 	tilcdc_tfp410_init();
+	tilcdc_slave_init();
 	return platform_driver_register(&tilcdc_platform_driver);
 }
 
···
 {
 	DBG("fini");
 	tilcdc_tfp410_fini();
+	tilcdc_slave_fini();
 	platform_driver_unregister(&tilcdc_platform_driver);
 }
 
-module_init(tilcdc_drm_init);
+late_initcall(tilcdc_drm_init);
 module_exit(tilcdc_drm_fini);
 
 MODULE_AUTHOR("Rob Clark <[e-mail]");

drivers/gpu/drm/tilcdc/tilcdc_slave.c

···
+/*
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Rob Clark <[e-mail]>
+ *
+ * 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/i2c.h>
+#include <linux/of_i2c.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/consumer.h>
+#include <drm/drm_encoder_slave.h>
+
+#include "tilcdc_drv.h"
+
+struct slave_module {
+	struct tilcdc_module base;
+	struct i2c_adapter *i2c;
+};
+#define to_slave_module(x) container_of(x, struct slave_module, base)
+
+static const struct tilcdc_panel_info slave_info = {
+		.bpp                    = 16,
+		.ac_bias                = 255,
+		.ac_bias_intrpt         = 0,
+		.dma_burst_sz           = 16,
+		.fdd                    = 0x80,
+		.tft_alt_mode           = 0,
+		.sync_edge              = 0,
+		.sync_ctrl              = 1,
+		.raster_order           = 0,
+};
+
+
+/*
+ * Encoder:
+ */
+
+struct slave_encoder {
+	struct drm_encoder_slave base;
+	struct slave_module *mod;
+};
+#define to_slave_encoder(x) container_of(to_encoder_slave(x), struct slave_encoder, base)
+
+static inline struct drm_encoder_slave_funcs *
+get_slave_funcs(struct drm_encoder *enc)
+{
+	return to_encoder_slave(enc)->slave_funcs;
+}
+
+static void slave_encoder_destroy(struct drm_encoder *encoder)
+{
+	struct slave_encoder *slave_encoder = to_slave_encoder(encoder);
+	if (get_slave_funcs(encoder))
+		get_slave_funcs(encoder)->destroy(encoder);
+	drm_encoder_cleanup(encoder);
+	kfree(slave_encoder);
+}
+
+static void slave_encoder_prepare(struct drm_encoder *encoder)
+{
+	drm_i2c_encoder_prepare(encoder);
+	tilcdc_crtc_set_panel_info(encoder->crtc, &slave_info);
+}
+
+static const struct drm_encoder_funcs slave_encoder_funcs = {
+		.destroy        = slave_encoder_destroy,
+};
+
+static const struct drm_encoder_helper_funcs slave_encoder_helper_funcs = {
+		.dpms           = drm_i2c_encoder_dpms,
+		.mode_fixup     = drm_i2c_encoder_mode_fixup,
+		.prepare        = slave_encoder_prepare,
+		.commit         = drm_i2c_encoder_commit,
+		.mode_set       = drm_i2c_encoder_mode_set,
+		.save           = drm_i2c_encoder_save,
+		.restore        = drm_i2c_encoder_restore,
+};
+
+static const struct i2c_board_info info = {
+		I2C_BOARD_INFO("tda998x", 0x70)
+};
+
+static struct drm_encoder *slave_encoder_create(struct drm_device *dev,
+		struct slave_module *mod)
+{
+	struct slave_encoder *slave_encoder;
+	struct drm_encoder *encoder;
+	int ret;
+
+	slave_encoder = kzalloc(sizeof(*slave_encoder), GFP_KERNEL);
+	if (!slave_encoder) {
+		dev_err(dev->dev, "allocation failed\n");
+		return NULL;
+	}
+
+	slave_encoder->mod = mod;
+
+	encoder = &slave_encoder->base.base;
+	encoder->possible_crtcs = 1;
+
+	ret = drm_encoder_init(dev, encoder, &slave_encoder_funcs,
+			DRM_MODE_ENCODER_TMDS);
+	if (ret)
+		goto fail;
+
+	drm_encoder_helper_add(encoder, &slave_encoder_helper_funcs);
+
+	ret = drm_i2c_encoder_init(dev, to_encoder_slave(encoder), mod->i2c, &info);
+	if (ret)
+		goto fail;
+
+	return encoder;
+
+fail:
+	slave_encoder_destroy(encoder);
+	return NULL;
+}
+
+/*
+ * Connector:
+ */
+
+struct slave_connector {
+	struct drm_connector base;
+
+	struct drm_encoder *encoder;  /* our connected encoder */
+	struct slave_module *mod;
+};
+#define to_slave_connector(x) container_of(x, struct slave_connector, base)
+
+static void slave_connector_destroy(struct drm_connector *connector)
+{
+	struct slave_connector *slave_connector = to_slave_connector(connector);
+	drm_connector_cleanup(connector);
+	kfree(slave_connector);
+}
+
+static enum drm_connector_status slave_connector_detect(
+		struct drm_connector *connector,
+		bool force)
+{
+	struct drm_encoder *encoder = to_slave_connector(connector)->encoder;
+	return get_slave_funcs(encoder)->detect(encoder, connector);
+}
+
+static int slave_connector_get_modes(struct drm_connector *connector)
+{
+	struct drm_encoder *encoder = to_slave_connector(connector)->encoder;
+	return get_slave_funcs(encoder)->get_modes(encoder, connector);
+}
+
+static int slave_connector_mode_valid(struct drm_connector *connector,
+		  struct drm_display_mode *mode)
+{
+	struct drm_encoder *encoder = to_slave_connector(connector)->encoder;
+	struct tilcdc_drm_private *priv = connector->dev->dev_private;
+	int ret;
+
+	ret = tilcdc_crtc_mode_valid(priv->crtc, mode);
+	if (ret != MODE_OK)
+		return ret;
+
+	return get_slave_funcs(encoder)->mode_valid(encoder, mode);
+}
+
+static struct drm_encoder *slave_connector_best_encoder(
+		struct drm_connector *connector)
+{
+	struct slave_connector *slave_connector = to_slave_connector(connector);
+	return slave_connector->encoder;
+}
+
+static int slave_connector_set_property(struct drm_connector *connector,
+		struct drm_property *property, uint64_t value)
+{
+	struct drm_encoder *encoder = to_slave_connector(connector)->encoder;
+	return get_slave_funcs(encoder)->set_property(encoder,
+			connector, property, value);
+}
+
+static const struct drm_connector_funcs slave_connector_funcs = {
+	.destroy            = slave_connector_destroy,
+	.dpms               = drm_helper_connector_dpms,
+	.detect             = slave_connector_detect,
+	.fill_modes         = drm_helper_probe_single_connector_modes,
+	.set_property       = slave_connector_set_property,
+};
+
+static const struct drm_connector_helper_funcs slave_connector_helper_funcs = {
+	.get_modes          = slave_connector_get_modes,
+	.mode_valid         = slave_connector_mode_valid,
+	.best_encoder       = slave_connector_best_encoder,
+};
+
+static struct drm_connector *slave_connector_create(struct drm_device *dev,
+		struct slave_module *mod, struct drm_encoder *encoder)
+{
+	struct slave_connector *slave_connector;
+	struct drm_connector *connector;
+	int ret;
+
+	slave_connector = kzalloc(sizeof(*slave_connector), GFP_KERNEL);
+	if (!slave_connector) {
+		dev_err(dev->dev, "allocation failed\n");
+		return NULL;
+	}
+
+	slave_connector->encoder = encoder;
+	slave_connector->mod = mod;
+
+	connector = &slave_connector->base;
+
+	drm_connector_init(dev, connector, &slave_connector_funcs,
+			DRM_MODE_CONNECTOR_HDMIA);
+	drm_connector_helper_add(connector, &slave_connector_helper_funcs);
+
+	connector->polled = DRM_CONNECTOR_POLL_CONNECT |
+			DRM_CONNECTOR_POLL_DISCONNECT;
+
+	connector->interlace_allowed = 0;
+	connector->doublescan_allowed = 0;
+
+	get_slave_funcs(encoder)->create_resources(encoder, connector);
+
+	ret = drm_mode_connector_attach_encoder(connector, encoder);
+	if (ret)
+		goto fail;
+
+	drm_sysfs_connector_add(connector);
+
+	return connector;
+
+fail:
+	slave_connector_destroy(connector);
+	return NULL;
+}
+
+/*
+ * Module:
+ */
+
+static int slave_modeset_init(struct tilcdc_module *mod, struct drm_device *dev)
+{
+	struct slave_module *slave_mod = to_slave_module(mod);
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	struct drm_encoder *encoder;
+	struct drm_connector *connector;
+
+	encoder = slave_encoder_create(dev, slave_mod);
+	if (!encoder)
+		return -ENOMEM;
+
+	connector = slave_connector_create(dev, slave_mod, encoder);
+	if (!connector)
+		return -ENOMEM;
+
+	priv->encoders[priv->num_encoders++] = encoder;
+	priv->connectors[priv->num_connectors++] = connector;
+
+	return 0;
+}
+
+static void slave_destroy(struct tilcdc_module *mod)
+{
+	struct slave_module *slave_mod = to_slave_module(mod);
+
+	tilcdc_module_cleanup(mod);
+	kfree(slave_mod);
+}
+
+static const struct tilcdc_module_ops slave_module_ops = {
+		.modeset_init = slave_modeset_init,
+		.destroy = slave_destroy,
+};
+
+/*
+ * Device:
+ */
+
+static struct of_device_id slave_of_match[];
+
+static int slave_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct device_node *i2c_node;
+	struct slave_module *slave_mod;
+	struct tilcdc_module *mod;
+	struct pinctrl *pinctrl;
+	uint32_t i2c_phandle;
+	int ret = -EINVAL;
+
+	/* bail out early if no DT data: */
+	if (!node) {
+		dev_err(&pdev->dev, "device-tree data is missing\n");
+		return -ENXIO;
+	}
+
+	slave_mod = kzalloc(sizeof(*slave_mod), GFP_KERNEL);
+	if (!slave_mod)
+		return -ENOMEM;
+
+	mod = &slave_mod->base;
+
+	tilcdc_module_init(mod, "slave", &slave_module_ops);
+
+	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
+	if (IS_ERR(pinctrl))
+		dev_warn(&pdev->dev, "pins are not configured\n");
+
+	if (of_property_read_u32(node, "i2c", &i2c_phandle)) {
+		dev_err(&pdev->dev, "could not get i2c bus phandle\n");
+		goto fail;
+	}
+
+	i2c_node = of_find_node_by_phandle(i2c_phandle);
+	if (!i2c_node) {
+		dev_err(&pdev->dev, "could not get i2c bus node\n");
+		goto fail;
+	}
+
+	slave_mod->i2c = of_find_i2c_adapter_by_node(i2c_node);
+	if (!slave_mod->i2c) {
+		dev_err(&pdev->dev, "could not get i2c\n");
+		goto fail;
+	}
+
+	of_node_put(i2c_node);
+
+	return 0;
+
+fail:
+	slave_destroy(mod);
+	return ret;
+}
+
+static int slave_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static struct of_device_id slave_of_match[] = {
+		{ .compatible = "ti,tilcdc,slave", },
+		{ },
+};
+MODULE_DEVICE_TABLE(of, slave_of_match);
+
+struct platform_driver slave_driver = {
+	.probe = slave_probe,
+	.remove = slave_remove,
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "slave",
+		.of_match_table = slave_of_match,
+	},
+};
+
+int __init tilcdc_slave_init(void)
+{
+	return platform_driver_register(&slave_driver);
+}
+
+void __exit tilcdc_slave_fini(void)
+{
+	platform_driver_unregister(&slave_driver);
+}

drivers/gpu/drm/tilcdc/tilcdc_slave.h

···
+/*
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Rob Clark <[e-mail]>
+ *
+ * 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_SLAVE_H__
+#define __TILCDC_SLAVE_H__
+
+/* sub-module for i2c slave encoder output */
+
+int tilcdc_slave_init(void);
+void tilcdc_slave_fini(void);
+
+#endif /* __TILCDC_SLAVE_H__ */