There exist simple vga encoders without any type of management interface
and just maybe a simple gpio for turning it on or off. Examples for these
are the Analog Devices ADV7123, Chipsea CS7123 or Micronas SDA7123.
Add a generic encoder driver for those that can be used by drm drivers
using the component framework.
Signed-off-by: Heiko Stuebner <heiko at sntech.de>
---
drivers/gpu/drm/i2c/Kconfig | 6 +
drivers/gpu/drm/i2c/Makefile | 2 +
drivers/gpu/drm/i2c/vga-simple.c | 325 +++++++++++++++++++++++++++++++++++++++
3 files changed, 333 insertions(+)
create mode 100644 drivers/gpu/drm/i2c/vga-simple.c
diff --git a/drivers/gpu/drm/i2c/Kconfig b/drivers/gpu/drm/i2c/Kconfig
index 22c7ed6..319f2cb 100644
--- a/drivers/gpu/drm/i2c/Kconfig
+++ b/drivers/gpu/drm/i2c/Kconfig
@@ -31,4 +31,10 @@ config DRM_I2C_NXP_TDA998X
help
Support for NXP Semiconductors TDA998X HDMI encoders.
+config DRM_VGA_SIMPLE
+ tristate "Generic simple vga encoder"
+ help
+ Support for vga encoder chips without any special settings
+ and at most a power-control gpio.
+
endmenu
diff --git a/drivers/gpu/drm/i2c/Makefile b/drivers/gpu/drm/i2c/Makefile
index 2c72eb5..858961f 100644
--- a/drivers/gpu/drm/i2c/Makefile
+++ b/drivers/gpu/drm/i2c/Makefile
@@ -10,3 +10,5 @@ obj-$(CONFIG_DRM_I2C_SIL164) += sil164.o
tda998x-y := tda998x_drv.o
obj-$(CONFIG_DRM_I2C_NXP_TDA998X) += tda998x.o
+
+obj-$(CONFIG_DRM_VGA_SIMPLE) += vga-simple.o
diff --git a/drivers/gpu/drm/i2c/vga-simple.c b/drivers/gpu/drm/i2c/vga-simple.c
new file mode 100644
index 0000000..bb9d19c
--- /dev/null
+++ b/drivers/gpu/drm/i2c/vga-simple.c
@@ -0,0 +1,325 @@
+/*
+ * 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 <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 connector_to_vga_simple(x) container_of(x, struct vga_simple,
connector)
+#define encoder_to_vga_simple(x) container_of(x, struct vga_simple, encoder)
+
+struct vga_simple {
+ struct drm_connector connector;
+ struct drm_encoder encoder;
+
+ struct device *dev;
+ struct i2c_adapter *ddc;
+
+ struct regulator *vaa_reg;
+ struct gpio_desc *enable_gpio;
+
+ struct mutex enable_lock;
+ bool enabled;
+};
+
+/*
+ * Connector functions
+ */
+
+enum drm_connector_status vga_simple_detect(struct drm_connector *connector,
+ bool force)
+{
+ struct vga_simple *vga = connector_to_vga_simple(connector);
+
+ if (!vga->ddc)
+ return connector_status_unknown;
+
+ if (drm_probe_ddc(vga->ddc))
+ return connector_status_connected;
+
+ return connector_status_disconnected;
+}
+
+void vga_simple_connector_destroy(struct drm_connector *connector)
+{
+ drm_connector_unregister(connector);
+ drm_connector_cleanup(connector);
+}
+
+struct drm_connector_funcs vga_simple_connector_funcs = {
+ .dpms = drm_helper_connector_dpms,
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .detect = vga_simple_detect,
+ .destroy = vga_simple_connector_destroy,
+};
+
+/*
+ * Connector helper functions
+ */
+
+static int vga_simple_connector_get_modes(struct drm_connector *connector)
+{
+ struct vga_simple *vga = connector_to_vga_simple(connector);
+ struct edid *edid;
+ int ret = 0;
+
+ if (!vga->ddc)
+ return 0;
+
+ edid = drm_get_edid(connector, vga->ddc);
+ if (edid) {
+ drm_mode_connector_update_edid_property(connector, edid);
+ ret = drm_add_edid_modes(connector, edid);
+ kfree(edid);
+ }
+
+ return ret;
+}
+
+static int vga_simple_connector_mode_valid(struct drm_connector *connector,
+ struct drm_display_mode *mode)
+{
+ return MODE_OK;
+}
+
+static struct drm_encoder
+*vga_simple_connector_best_encoder(struct drm_connector *connector)
+{
+ struct vga_simple *vga = connector_to_vga_simple(connector);
+
+ return &vga->encoder;
+}
+
+static struct drm_connector_helper_funcs vga_simple_connector_helper_funcs = {
+ .get_modes = vga_simple_connector_get_modes,
+ .best_encoder = vga_simple_connector_best_encoder,
+ .mode_valid = vga_simple_connector_mode_valid,
+};
+
+/*
+ * Encoder functions
+ */
+
+static void vga_simple_encoder_destroy(struct drm_encoder *encoder)
+{
+ drm_encoder_cleanup(encoder);
+}
+
+static const struct drm_encoder_funcs vga_simple_encoder_funcs = {
+ .destroy = vga_simple_encoder_destroy,
+};
+
+/*
+ * Encoder helper functions
+ */
+
+static void vga_simple_encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+ struct vga_simple *vga = encoder_to_vga_simple(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->enable_gpio)
+ gpiod_set_value(vga->enable_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->enable_gpio)
+ gpiod_set_value(vga->enable_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_simple_mode_fixup(struct drm_encoder *encoder,
+ const struct drm_display_mode *mode,
+ struct drm_display_mode *adjusted_mode)
+{
+ return true;
+}
+
+static void vga_simple_encoder_prepare(struct drm_encoder *encoder)
+{
+}
+
+static void vga_simple_encoder_mode_set(struct drm_encoder *encoder,
+ struct drm_display_mode *mode,
+ struct drm_display_mode *adjusted_mode)
+{
+}
+
+static void vga_simple_encoder_commit(struct drm_encoder *encoder)
+{
+ vga_simple_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
+}
+
+static void vga_simple_encoder_disable(struct drm_encoder *encoder)
+{
+ vga_simple_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
+}
+
+static const struct drm_encoder_helper_funcs vga_simple_encoder_helper_funcs =
{
+ .dpms = vga_simple_encoder_dpms,
+ .mode_fixup = vga_simple_mode_fixup,
+ .prepare = vga_simple_encoder_prepare,
+ .mode_set = vga_simple_encoder_mode_set,
+ .commit = vga_simple_encoder_commit,
+ .disable = vga_simple_encoder_disable,
+};
+
+/*
+ * Component helper functions
+ */
+
+static int vga_simple_bind(struct device *dev, struct device *master,
+ void *data)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct drm_device *drm = data;
+
+ struct device_node *ddc_node, *np = pdev->dev.of_node;
+ struct vga_simple *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->enable_gpio = devm_gpiod_get_optional(dev, "enable",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(vga->enable_gpio)) {
+ ret = PTR_ERR(vga->enable_gpio);
+ dev_err(dev, "failed to request GPIO: %d\n", ret);
+ return ret;
+ }
+
+ vga->enabled = false;
+
+ ddc_node = of_parse_phandle(np, "ddc-i2c-bus", 0);
+ if (ddc_node) {
+ vga->ddc = of_find_i2c_adapter_by_node(ddc_node);
+ of_node_put(ddc_node);
+ if (!vga->ddc) {
+ dev_dbg(vga->dev, "failed to read ddc node\n");
+ return -EPROBE_DEFER;
+ }
+ } else {
+ dev_dbg(vga->dev, "no ddc property found\n");
+ }
+
+ vga->vaa_reg = devm_regulator_get_optional(dev, "vaa");
+
+ vga->encoder.possible_crtcs = drm_of_find_possible_crtcs(drm, np);
+ vga->encoder.of_node = np;
+ vga->connector.polled = DRM_CONNECTOR_POLL_CONNECT |
+ DRM_CONNECTOR_POLL_DISCONNECT;
+
+ drm_encoder_helper_add(&vga->encoder, &vga_simple_encoder_helper_funcs);
+ drm_encoder_init(drm, &vga->encoder, &vga_simple_encoder_funcs,
+ DRM_MODE_ENCODER_DAC);
+
+ drm_connector_helper_add(&vga->connector,
+ &vga_simple_connector_helper_funcs);
+ drm_connector_init(drm, &vga->connector, &vga_simple_connector_funcs,
+ DRM_MODE_CONNECTOR_VGA);
+
+ drm_mode_connector_attach_encoder(&vga->connector, &vga->encoder);
+
+ return 0;
+}
+
+static void vga_simple_unbind(struct device *dev, struct device *master,
+ void *data)
+{
+ struct vga_simple *vga = dev_get_drvdata(dev);
+
+ vga->connector.funcs->destroy(&vga->connector);
+ vga->encoder.funcs->destroy(&vga->encoder);
+}
+
+static const struct component_ops vga_simple_ops = {
+ .bind = vga_simple_bind,
+ .unbind = vga_simple_unbind,
+};
+
+static int vga_simple_probe(struct platform_device *pdev)
+{
+ return component_add(&pdev->dev, &vga_simple_ops);
+}
+
+static int vga_simple_remove(struct platform_device *pdev)
+{
+ component_del(&pdev->dev, &vga_simple_ops);
+
+ return 0;
+}
+
+static const struct of_device_id vga_simple_ids[] = {
+ { .compatible = "adi,adv7123", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, vga_simple_ids);
+
+static struct platform_driver vga_simple_driver = {
+ .probe = vga_simple_probe,
+ .remove = vga_simple_remove,
+ .driver = {
+ .name = "vga-simple",
+ .of_match_table = vga_simple_ids,
+ },
+};
+module_platform_driver(vga_simple_driver);
+
+MODULE_AUTHOR("Heiko Stuebner <heiko at sntech.de>");
+MODULE_DESCRIPTION("Simple vga converter");
+MODULE_LICENSE("GPL");
--
2.1.1
