Re: [PATCH V7 03/12] drm/bridge: Add helper functions for drm_bridge

On Wed, Aug 27, 2014 at 10:29 AM, Ajay Kumar ajaykumar.rs@samsung.com wrote:

A set of helper functions are defined in this patch to make bridge driver probe independent of the drm flow.

The bridge devices register themselves on a lookup table when they get probed by calling "drm_bridge_add".

The parent encoder driver waits till the bridge is available in the lookup table(by calling "of_drm_find_bridge") and then continues with its initialization.

The encoder driver should also call "drm_bridge_attach" to pass on the drm_device, encoder pointers to the bridge object.

drm_bridge_attach inturn calls drm_bridge_init to register itself with the drm core. Later, it calls "bridge->funcs->attach" so that bridge can continue with other initializations.

Signed-off-by: Ajay Kumar ajaykumar.rs@samsung.com

drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/bridge/Kconfig | 15 ++++- drivers/gpu/drm/drm_bridge.c | 102 ++++++++++++++++++++++++++++++++ drivers/gpu/drm/drm_crtc.c | 4 +- drivers/gpu/drm/msm/hdmi/hdmi_bridge.c | 4 +- include/drm/drm_crtc.h | 12 +++- 6 files changed, 131 insertions(+), 7 deletions(-) create mode 100644 drivers/gpu/drm/drm_bridge.c

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 4a55d59..bdbfb6f 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -19,6 +19,7 @@ drm-y := drm_auth.o drm_buffer.o drm_bufs.o drm_cache.o \ drm-$(CONFIG_COMPAT) += drm_ioc32.o drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o drm-$(CONFIG_PCI) += ati_pcigart.o +drm-$(CONFIG_DRM_BRIDGE) += drm_bridge.o drm-$(CONFIG_DRM_PANEL) += drm_panel.o drm-$(CONFIG_OF) += drm_of.o

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index 884923f..5a8e907 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -1,5 +1,16 @@ -config DRM_PTN3460

•   tristate "PTN3460 DP/LVDS bridge"
  

+config DRM_BRIDGE

I'm not convinced this adds any value, to be honest. In addition to whether or not it's useful, it seems like you'd need to stub the drm_bridge_* functions that are declared in drm_crtc.h or break them out into drm_bridge.h.

Sean

•   tristate
    depends on DRM
    select DRM_KMS_HELPER
  

•   help
  

•     Bridge registration and lookup framework.
  

+menu "bridge chips"

•   depends on DRM_BRIDGE
  

+config DRM_PTN3460

•   tristate "PTN3460 DP/LVDS bridge"
  

•   depends on DRM_BRIDGE
    ---help---
  

+endmenu diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c new file mode 100644 index 0000000..b2d43fd --- /dev/null +++ b/drivers/gpu/drm/drm_bridge.c @@ -0,0 +1,102 @@ +/*

• • Copyright (c) 2014 Samsung Electronics Co., Ltd
• • Permission is hereby granted, free of charge, to any person obtaining a
• • copy of this software and associated documentation files (the "Software"),
• • to deal in the Software without restriction, including without limitation
• • the rights to use, copy, modify, merge, publish, distribute, sub license,
• • and/or sell copies of the Software, and to permit persons to whom the
• • Software is furnished to do so, subject to the following conditions:
• • The above copyright notice and this permission notice (including the
• • next paragraph) shall be included in all copies or substantial portions
• • of the Software.
• • THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
• • IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
• • FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
• • THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
• • LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
• • FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
• • DEALINGS IN THE SOFTWARE.
• */

+#include <linux/err.h> +#include <linux/module.h>

+#include <drm/drm_crtc.h>

+#include "drm/drmP.h"

+static DEFINE_MUTEX(bridge_lock); +static LIST_HEAD(bridge_list);

+int drm_bridge_add(struct drm_bridge *bridge) +{

•   mutex_lock(&bridge_lock);
  

•   list_add_tail(&bridge->list, &bridge_list);
  

•   mutex_unlock(&bridge_lock);
  

•   return 0;
  

+} +EXPORT_SYMBOL(drm_bridge_add);

+void drm_bridge_remove(struct drm_bridge *bridge) +{

•   mutex_lock(&bridge_lock);
  

•   list_del_init(&bridge->list);
  

•   mutex_unlock(&bridge_lock);
  

+} +EXPORT_SYMBOL(drm_bridge_remove);

+int drm_bridge_attach(struct drm_bridge *bridge,

•                           struct drm_encoder *encoder)
  

+{

•   int ret;
  

•   if (!bridge || !encoder)
  

•           return -EINVAL;
  

•   if (bridge->encoder)
  

•           return -EBUSY;
  

•   encoder->bridge = bridge;
  

•   bridge->encoder = encoder;
  

•   bridge->drm = encoder->dev;
  

•   ret = drm_bridge_init(bridge->drm, bridge);
  

•   if (ret) {
  

•           DRM_ERROR("Failed to register bridge with drm\n");
  

•           return ret;
  

•   }
  

•   if (bridge->funcs->attach)
  

•           return bridge->funcs->attach(bridge);
  

•   return 0;
  

+} +EXPORT_SYMBOL(drm_bridge_attach);

+#ifdef CONFIG_OF +struct drm_bridge *of_drm_find_bridge(struct device_node *np) +{

•   struct drm_bridge *bridge;
  

•   mutex_lock(&bridge_lock);
  

•   list_for_each_entry(bridge, &bridge_list, list) {
  

•           if (bridge->dev->of_node == np) {
  

•                   mutex_unlock(&bridge_lock);
  

•                   return bridge;
  

•           }
  

•   }
  

•   mutex_unlock(&bridge_lock);
  

•   return NULL;
  

+} +EXPORT_SYMBOL(of_drm_find_bridge); +#endif

+MODULE_AUTHOR("Ajay Kumar ajaykumar.rs@samsung.com"); +MODULE_DESCRIPTION("DRM bridge infrastructure"); +MODULE_LICENSE("GPL and additional rights"); diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 25f5cfa..2fb22fa 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -1039,7 +1039,7 @@ int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge) if (ret) goto out;

•   bridge->dev = dev;
  

•   bridge->drm = dev;
  
    list_add_tail(&bridge->head, &dev->mode_config.bridge_list);
    dev->mode_config.num_bridge++;
  

@@ -1058,7 +1058,7 @@ EXPORT_SYMBOL(drm_bridge_init); */ void drm_bridge_cleanup(struct drm_bridge *bridge) {

•   struct drm_device *dev = bridge->dev;
  

•   struct drm_device *dev = bridge->drm;
  
    drm_modeset_lock_all(dev);
    drm_mode_object_put(dev, &bridge->base);
  

diff --git a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c index 0309539..bc9e5ff 100644 --- a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c +++ b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c @@ -33,7 +33,7 @@ static void hdmi_bridge_destroy(struct drm_bridge *bridge)

static void power_on(struct drm_bridge *bridge) {

•   struct drm_device *dev = bridge->dev;
  

•   struct drm_device *dev = bridge->drm;
    struct hdmi_bridge *hdmi_bridge = to_hdmi_bridge(bridge);
    struct hdmi *hdmi = hdmi_bridge->hdmi;
    const struct hdmi_platform_config *config = hdmi->config;
  

@@ -67,7 +67,7 @@ static void power_on(struct drm_bridge *bridge)

static void power_off(struct drm_bridge *bridge) {

•   struct drm_device *dev = bridge->dev;
  

•   struct drm_device *dev = bridge->drm;
    struct hdmi_bridge *hdmi_bridge = to_hdmi_bridge(bridge);
    struct hdmi *hdmi = hdmi_bridge->hdmi;
    const struct hdmi_platform_config *config = hdmi->config;
  

diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index f48a436..f6f426f 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -629,6 +629,7 @@ struct drm_plane {

/**

• drm_bridge_funcs - drm_bridge control functions

• • @attach: Called during drm_bridge_attach
  • @mode_fixup: Try to fixup (or reject entirely) proposed mode for this bridge
  • @disable: Called right before encoder prepare, disables the bridge
  • @post_disable: Called right after encoder prepare, for lockstepped disable

@@ -638,6 +639,7 @@ struct drm_plane {

• @destroy: make object go away

*/ struct drm_bridge_funcs {

•   int (*attach)(struct drm_bridge *bridge);
    bool (*mode_fixup)(struct drm_bridge *bridge,
                       const struct drm_display_mode *mode,
                       struct drm_display_mode *adjusted_mode);
  

@@ -660,8 +662,11 @@ struct drm_bridge_funcs {

• @driver_private: pointer to the bridge driver's internal context

*/ struct drm_bridge {

•   struct drm_device *dev;
  

•   struct device *dev;
  

•   struct drm_device *drm;
  

•   struct drm_encoder *encoder;
    struct list_head head;
  

•   struct list_head list;
  
    struct drm_mode_object base;
  
  

@@ -906,6 +911,11 @@ extern void drm_connector_cleanup(struct drm_connector *connector); /* helper to unplug all connectors from sysfs for device */ extern void drm_connector_unplug_all(struct drm_device *dev);

+extern int drm_bridge_add(struct drm_bridge *bridge); +extern void drm_bridge_remove(struct drm_bridge *bridge); +extern struct drm_bridge *of_drm_find_bridge(struct device_node *np); +extern int drm_bridge_attach(struct drm_bridge *bridge,

•                           struct drm_encoder *encoder);
  

extern int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge); extern void drm_bridge_cleanup(struct drm_bridge *bridge);

-- 1.7.9.5

-- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html