[PATCH v4 6/6] drm/dsi: Get DSI host by DT device node

[Archit Taneja]

On 01/21/2016 09:46 PM, Thierry Reding wrote:
> On Thu, Dec 10, 2015 at 06:11:40PM +0530, Archit Taneja wrote:
>> mipi_dsi_devices are inherently aware of their host because they
>> share a parent-child hierarchy in the device tree.
>>
>> non-dsi drivers that create dsi device don't have this data. In order to
>> get this information, they require to a phandle to the dsi host in the
>> device tree.
>>
>> Maintain a list of all the hosts DSI that are currently registered.
>>
>> This list will be used to find the mipi_dsi_host corresponding to the
>> device_node passed in of_find_mipi_dsi_host_by_node.
>>
>> Reviewed-by: Andrzej Hajda 
>> Signed-off-by: Archit Taneja 
>> ---
>>   drivers/gpu/drm/drm_mipi_dsi.c | 38 ++
>>   include/drm/drm_mipi_dsi.h |  3 +++
>>   2 files changed, 41 insertions(+)
>
> Please be more consistent with the spelling. Abbreviations should be all
> capitals. Also s/mipi_dsi_devices/MIPI DSI devices/, and so on.

I'll ensure the abbreviations are consistent in the next revision.

>
> Otherwise I guess this makes sense.

Thanks for the review.

Thanks,
Archit

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[PATCH v4 6/6] drm/dsi: Get DSI host by DT device node

[Thierry Reding]

On Thu, Dec 10, 2015 at 06:11:40PM +0530, Archit Taneja wrote:
> mipi_dsi_devices are inherently aware of their host because they
> share a parent-child hierarchy in the device tree.
> 
> non-dsi drivers that create dsi device don't have this data. In order to
> get this information, they require to a phandle to the dsi host in the
> device tree.
> 
> Maintain a list of all the hosts DSI that are currently registered.
> 
> This list will be used to find the mipi_dsi_host corresponding to the
> device_node passed in of_find_mipi_dsi_host_by_node.
> 
> Reviewed-by: Andrzej Hajda 
> Signed-off-by: Archit Taneja 
> ---
>  drivers/gpu/drm/drm_mipi_dsi.c | 38 ++
>  include/drm/drm_mipi_dsi.h |  3 +++
>  2 files changed, 41 insertions(+)

Please be more consistent with the spelling. Abbreviations should be all
capitals. Also s/mipi_dsi_devices/MIPI DSI devices/, and so on.

Otherwise I guess this makes sense.

Thierry
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[PATCH v4 6/6] drm/dsi: Get DSI host by DT device node

[Archit Taneja]

mipi_dsi_devices are inherently aware of their host because they
share a parent-child hierarchy in the device tree.

non-dsi drivers that create dsi device don't have this data. In order to
get this information, they require to a phandle to the dsi host in the
device tree.

Maintain a list of all the hosts DSI that are currently registered.

This list will be used to find the mipi_dsi_host corresponding to the
device_node passed in of_find_mipi_dsi_host_by_node.

Reviewed-by: Andrzej Hajda 
Signed-off-by: Archit Taneja 
---
 drivers/gpu/drm/drm_mipi_dsi.c | 38 ++
 include/drm/drm_mipi_dsi.h |  3 +++
 2 files changed, 41 insertions(+)

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 7a81171..e40a665 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -213,6 +213,36 @@ of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct 
device_node *node)
 }
 #endif

+static DEFINE_MUTEX(host_lock);
+static LIST_HEAD(host_list);
+
+/**
+ * of_find_mipi_dsi_host_by_node() - find the MIPI DSI host matching a
+ *device tree node
+ * @node: device tree node
+ *
+ * Return: A pointer to the MIPI DSI host corresponding to @np or NULL if no
+ *such device exists (or has not been registered yet).
+ */
+struct mipi_dsi_host *of_find_mipi_dsi_host_by_node(struct device_node *node)
+{
+   struct mipi_dsi_host *host;
+
+   mutex_lock(_lock);
+
+   list_for_each_entry(host, _list, list) {
+   if (host->dev->of_node == node) {
+   mutex_unlock(_lock);
+   return host;
+   }
+   }
+
+   mutex_unlock(_lock);
+
+   return NULL;
+}
+EXPORT_SYMBOL(of_find_mipi_dsi_host_by_node);
+
 int mipi_dsi_host_register(struct mipi_dsi_host *host)
 {
struct device_node *node;
@@ -224,6 +254,10 @@ int mipi_dsi_host_register(struct mipi_dsi_host *host)
of_mipi_dsi_device_add(host, node);
}

+   mutex_lock(_lock);
+   list_add_tail(>list, _list);
+   mutex_unlock(_lock);
+
return 0;
 }
 EXPORT_SYMBOL(mipi_dsi_host_register);
@@ -240,6 +274,10 @@ static int mipi_dsi_remove_device_fn(struct device *dev, 
void *priv)
 void mipi_dsi_host_unregister(struct mipi_dsi_host *host)
 {
device_for_each_child(host->dev, NULL, mipi_dsi_remove_device_fn);
+
+   mutex_lock(_lock);
+   list_del_init(>list);
+   mutex_unlock(_lock);
 }
 EXPORT_SYMBOL(mipi_dsi_host_unregister);

diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index 410d8b5..e5c1df9 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -96,14 +96,17 @@ struct mipi_dsi_host_ops {
  * struct mipi_dsi_host - DSI host device
  * @dev: driver model device node for this DSI host
  * @ops: DSI host operations
+ * @list: list management
  */
 struct mipi_dsi_host {
struct device *dev;
const struct mipi_dsi_host_ops *ops;
+   struct list_head list;
 };

 int mipi_dsi_host_register(struct mipi_dsi_host *host);
 void mipi_dsi_host_unregister(struct mipi_dsi_host *host);
+struct mipi_dsi_host *of_find_mipi_dsi_host_by_node(struct device_node *node);

 /* DSI mode flags */

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