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@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@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@sntech.de"); +MODULE_DESCRIPTION("Simple vga converter"); +MODULE_LICENSE("GPL");