[PATCH RFC v2 04/12] drm/components: add generic vga encoder driver

Heiko Stuebner heiko at sntech.de
Wed Apr 1 03:09:38 PDT 2015


This adds a driver for generic vga encoders like the Analog Devices adv7123
and similar ics. These chips do not have any special configuration options
except a powersafe gpio.

An exception is added for the rcar-du driver which also implements support
for the adv7123 internally but is not yet converted to the component framework.

Signed-off-by: Heiko Stuebner <heiko at sntech.de>
---
 drivers/gpu/drm/components/Kconfig       |   5 +
 drivers/gpu/drm/components/Makefile      |   2 +
 drivers/gpu/drm/components/vga-encoder.c | 315 +++++++++++++++++++++++++++++++
 3 files changed, 322 insertions(+)
 create mode 100644 drivers/gpu/drm/components/vga-encoder.c

diff --git a/drivers/gpu/drm/components/Kconfig b/drivers/gpu/drm/components/Kconfig
index 9d5d462..647cea6 100644
--- a/drivers/gpu/drm/components/Kconfig
+++ b/drivers/gpu/drm/components/Kconfig
@@ -1,4 +1,9 @@
 menu "Standalone components for use with the component framework"
      depends on DRM && DRM_KMS_HELPER
 
+config DRM_COMPONENTS_VGA_ENCODER
+	tristate "Generic vga encoder"
+	help
+	  Support for generic vga encoder chips without any special controls.
+
 endmenu
diff --git a/drivers/gpu/drm/components/Makefile b/drivers/gpu/drm/components/Makefile
index be16eca..719b1c9 100644
--- a/drivers/gpu/drm/components/Makefile
+++ b/drivers/gpu/drm/components/Makefile
@@ -1 +1,3 @@
 ccflags-y := -Iinclude/drm
+
+obj-$(CONFIG_DRM_COMPONENTS_VGA_ENCODER) += vga-encoder.o
diff --git a/drivers/gpu/drm/components/vga-encoder.c b/drivers/gpu/drm/components/vga-encoder.c
new file mode 100644
index 0000000..f559b5e
--- /dev/null
+++ b/drivers/gpu/drm/components/vga-encoder.c
@@ -0,0 +1,315 @@
+/*
+ * Simple vga encoder driver
+ *
+ * Copyright (C) 2014 Heiko Stuebner <heiko at sntech.de>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/component.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/regulator/consumer.h>
+#include <linux/of_graph.h>
+#include <drm/drm_of.h>
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_edid.h>
+
+#define encoder_to_vga_encoder(x) container_of(x, struct vga_encoder, encoder)
+
+struct vga_encoder {
+	struct drm_encoder encoder;
+	struct device *dev;
+	struct regulator *vaa_reg;
+	struct gpio_desc *psave_gpio;
+
+	struct mutex enable_lock;
+	bool enabled;
+};
+
+static void vga_encoder_destroy(struct drm_encoder *encoder)
+{
+	drm_encoder_cleanup(encoder);
+}
+
+static const struct drm_encoder_funcs vga_encoder_funcs = {
+	.destroy = vga_encoder_destroy,
+};
+
+static void vga_encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+	struct vga_encoder *vga = encoder_to_vga_encoder(encoder);
+
+	mutex_lock(&vga->enable_lock);
+
+	switch (mode) {
+	case DRM_MODE_DPMS_ON:
+		if (vga->enabled)
+			goto out;
+
+		if (!IS_ERR(vga->vaa_reg))
+			regulator_enable(vga->vaa_reg);
+
+		if (vga->psave_gpio)
+			gpiod_set_value(vga->psave_gpio, 1);
+
+		vga->enabled = true;
+		break;
+	case DRM_MODE_DPMS_STANDBY:
+	case DRM_MODE_DPMS_SUSPEND:
+	case DRM_MODE_DPMS_OFF:
+		if (!vga->enabled)
+			goto out;
+
+		if (vga->psave_gpio)
+			gpiod_set_value(vga->psave_gpio, 0);
+
+		if (!IS_ERR(vga->vaa_reg))
+			regulator_enable(vga->vaa_reg);
+
+		vga->enabled = false;
+		break;
+	default:
+		break;
+	}
+
+out:
+	mutex_unlock(&vga->enable_lock);
+}
+
+static bool vga_encoder_mode_fixup(struct drm_encoder *encoder,
+				  const struct drm_display_mode *mode,
+				  struct drm_display_mode *adjusted_mode)
+{
+	return true;
+}
+
+static void vga_encoder_prepare(struct drm_encoder *encoder)
+{
+}
+
+static void vga_encoder_mode_set(struct drm_encoder *encoder,
+					struct drm_display_mode *mode,
+					struct drm_display_mode *adjusted_mode)
+{
+}
+
+static void vga_encoder_commit(struct drm_encoder *encoder)
+{
+	vga_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
+}
+
+static void vga_encoder_disable(struct drm_encoder *encoder)
+{
+	vga_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
+}
+
+static const struct drm_encoder_helper_funcs vga_encoder_helper_funcs = {
+	.dpms = vga_encoder_dpms,
+	.mode_fixup = vga_encoder_mode_fixup,
+	.prepare = vga_encoder_prepare,
+	.mode_set = vga_encoder_mode_set,
+	.commit = vga_encoder_commit,
+	.disable = vga_encoder_disable,
+};
+
+/*
+ * Component helper functions
+ */
+
+static int vga_encoder_bind(struct device *dev, struct device *master,
+				 void *data)
+{
+	struct vga_encoder *vga = dev_get_drvdata(dev);
+	struct device_node *np = vga->encoder.of_node;
+	struct drm_device *drm_dev = data;
+
+	vga->encoder.possible_crtcs = drm_of_find_possible_crtcs(drm_dev, np);
+
+	drm_encoder_helper_add(&vga->encoder, &vga_encoder_helper_funcs);
+	drm_encoder_init(drm_dev, &vga->encoder, &vga_encoder_funcs,
+			 DRM_MODE_ENCODER_DAC);
+
+	return component_bind_all(dev, drm_dev);
+}
+
+static void vga_encoder_unbind(struct device *dev, struct device *master,
+				    void *data)
+{
+	struct vga_encoder *vga = dev_get_drvdata(dev);
+	struct drm_device *drm_dev = data;
+
+	component_unbind_all(dev, drm_dev);
+	vga->encoder.funcs->destroy(&vga->encoder);
+}
+
+static const struct component_ops vga_encoder_ops = {
+	.bind = vga_encoder_bind,
+	.unbind = vga_encoder_unbind,
+};
+
+static int compare_of(struct device *dev, void *data)
+{
+	return dev->of_node == data;
+}
+
+static int vga_encoder_master_bind(struct device *dev)
+{
+	return 0;
+}
+
+static void vga_encoder_master_unbind(struct device *dev)
+{
+	/* do nothing */
+}
+
+static const struct component_master_ops vga_encoder_master_ops = {
+	.bind = vga_encoder_master_bind,
+	.unbind = vga_encoder_master_unbind,
+};
+
+static int vga_encoder_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *port, *connector_node;
+	struct device *dev = &pdev->dev;
+	struct component_match *match = NULL;
+	struct vga_encoder *vga;
+	int ret;
+
+	if (!np)
+		return -ENODEV;
+
+	vga = devm_kzalloc(dev, sizeof(*vga), GFP_KERNEL);
+	if (!vga)
+		return -ENOMEM;
+
+	vga->dev = dev;
+	dev_set_drvdata(dev, vga);
+	mutex_init(&vga->enable_lock);
+
+	vga->psave_gpio = devm_gpiod_get_optional(dev, "psave",
+						   GPIOD_OUT_LOW);
+	if (IS_ERR(vga->psave_gpio)) {
+		ret = PTR_ERR(vga->psave_gpio);
+		dev_err(dev, "failed to request GPIO: %d\n", ret);
+		return ret;
+	}
+
+	vga->enabled = false;
+	vga->vaa_reg = devm_regulator_get_optional(dev, "vaa");
+	vga->encoder.of_node = np;
+
+	port = of_graph_get_port_by_id(dev->of_node, 1);
+	if (port) {
+		struct device_node *endpoint;
+
+		endpoint = of_get_child_by_name(port, "endpoint");
+		if (endpoint) {
+			connector_node = of_graph_get_remote_port_parent(endpoint);
+			of_node_put(endpoint);
+		}
+
+		of_node_put(port);
+	}
+
+	if (!of_drm_find_connector(connector_node))
+		return -EPROBE_DEFER;
+
+	component_match_add(dev, &match, compare_of, connector_node);
+
+	ret = drm_encoder_add(&vga->encoder);
+	if (ret < 0)
+		return ret;
+
+	ret = component_master_add_with_match(dev, &vga_encoder_master_ops, match);
+	if (ret < 0)
+		goto err_encoder_remove;
+
+	ret = component_add(dev, &vga_encoder_ops);
+	if (ret < 0)
+		goto err_master_remove;
+
+	return 0;
+
+err_master_remove:
+	component_master_del(&pdev->dev, &vga_encoder_master_ops);
+err_encoder_remove:
+	drm_encoder_remove(&vga->encoder);
+
+	return ret;
+}
+
+static int vga_encoder_remove(struct platform_device *pdev)
+{
+	struct vga_encoder *vga = dev_get_drvdata(&pdev->dev);
+
+	component_del(&pdev->dev, &vga_encoder_ops);
+	component_master_del(&pdev->dev, &vga_encoder_master_ops);
+	drm_encoder_remove(&vga->encoder);
+
+	return 0;
+}
+
+static const struct of_device_id vga_encoder_ids[] = {
+	{ .compatible = "adi,adv7123", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, vga_encoder_ids);
+
+static struct platform_driver vga_encoder_driver = {
+	.probe  = vga_encoder_probe,
+	.remove = vga_encoder_remove,
+	.driver = {
+		.name = "vga-encoder",
+		.of_match_table = vga_encoder_ids,
+	},
+};
+
+static const struct of_device_id rcar_du_of_table[] = {
+	{ .compatible = "renesas,du-r8a7779" },
+	{ .compatible = "renesas,du-r8a7790" },
+	{ .compatible = "renesas,du-r8a7791" },
+	{ }
+};
+
+static int __init vga_encoder_init(void)
+{
+	struct device_node *np;
+
+	/*
+	 * Play nice with rcar-du that is having its own implementation
+	 * of the adv7123 binding implementation and is not yet
+	 * converted to using components.
+	 */
+	np = of_find_matching_node(NULL, rcar_du_of_table);
+	if (np) {
+		of_node_put(np);
+		return 0;
+	}
+
+	return platform_driver_register(&vga_encoder_driver);
+}
+
+static void __exit vga_encoder_exit(void)
+{
+	platform_driver_unregister(&vga_encoder_driver);
+}
+
+module_init(vga_encoder_init);
+module_exit(vga_encoder_exit);
+
+MODULE_AUTHOR("Heiko Stuebner <heiko at sntech.de>");
+MODULE_DESCRIPTION("Simple vga converter");
+MODULE_LICENSE("GPL");
-- 
2.1.4




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