On Thu, Oct 3, 2013 at 10:43 AM, Inki Dae <inki.dae@xxxxxxxxxxx> wrote:
> 2013/10/2 Sean Paul <seanpaul@xxxxxxxxxxxx>:
>> This patch adds code to look for the ptn3460 in the device tree file on
>> exynos initialization. If ptn node is found, the driver will initialize
>> the ptn3460 driver and skip creating a DP connector (since the bridge
>> driver will register its own connector).
>>
>> Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
>> ---
>> drivers/gpu/drm/exynos/exynos_drm_core.c | 44 +++++++++++++++++++++++++++++++-
>> 1 file changed, 43 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_core.c b/drivers/gpu/drm/exynos/exynos_drm_core.c
>> index 1bef6dc..9cf4476 100644
>> --- a/drivers/gpu/drm/exynos/exynos_drm_core.c
>> +++ b/drivers/gpu/drm/exynos/exynos_drm_core.c
>> @@ -12,7 +12,9 @@
>> * option) any later version.
>> */
>>
>> +#include <linux/of_i2c.h>
>> #include <drm/drmP.h>
>> +#include <drm/bridge/ptn3460.h>
>> #include "exynos_drm_drv.h"
>> #include "exynos_drm_encoder.h"
>> #include "exynos_drm_connector.h"
>> @@ -20,6 +22,40 @@
>>
>> static LIST_HEAD(exynos_drm_subdrv_list);
>>
>> +struct bridge_init {
>> + struct i2c_client *client;
>> + struct device_node *node;
>> +};
>> +
>> +static bool find_bridge(const char *name, struct bridge_init *bridge)
>> +{
>> + bridge->client = NULL;
>> + bridge->node = of_find_node_by_name(NULL, name);
>
> Not clear to me. Why do you try to handle device tree here, not real
> device driver?. How about adding a output property to board specific
> fimd dt node: i.e. output = <&ptn3460_bridge>?
The problem doing something like this is that we won't have a handle
to drm_device if it's just a standalone driver, and so we won't be
able to register the bridge or connector. We need this init call one
way or another.
> Actually, the output
> device of fimd hw could be one of MIPI-DSI, eDP, mDNIe, LVDS bridge,
> or LCD. And then, let's find ptn3460-bridge node in the fimd driver,
> and initialize the ptn3460 bridge driver, and get power on or off
> through exynos_drm_display_ops of the fimd driver. And all these
> codes could be hided from fimd driver by moving them into
> exynos_drm_display_ops. Of course, for this, you would need additional
> works. So let's do it if needed.
>
> The below is the outline of device tree I recommend,
>
> In board dts,
> i2c@I2CD000 {
> ptn3460_bridge: prn3460-bridge@20 {
> ...
> }
> }
>
> fimd@11c00000 {
> ...
> output_dev = <&ptn3460_bridge>;
> }
>
> With this, I believe that you can do all things you want for
> controlling the LVDS bridge in fimd driver.
>
No, this isn't what I want to do. The bridge should not hang off fimd
since it's a crtc. The bridge should only be initialized by the DP
driver (it doesn't make sense to initialize ptn when you're using
MIPI/LVDS/whatever).
Since the actual crtc/encoder drivers are abstracted through
exynos_drm_core/crtc/encoder, we need to initialize the ptn driver in
the abstraction layers in order to hook it directly into drm.
Sean
> Thanks,
> Inki Dae
>
>> + if (!bridge->node)
>> + return false;
>> +
>> + bridge->client = of_find_i2c_device_by_node(bridge->node);
>> + if (!bridge->client)
>> + return false;
>> +
>> + return true;
>> +}
>> +
>> +/* returns the number of bridges attached */
>> +static int exynos_drm_attach_lcd_bridge(struct drm_device *dev,
>> + struct drm_encoder *encoder)
>> +{
>> + struct bridge_init bridge;
>> + int ret;
>> +
>> + if (find_bridge("ptn3460-bridge", &bridge)) {
>> + ret = ptn3460_init(dev, encoder, bridge.client, bridge.node);
>> + if (!ret)
>> + return 1;
>> + }
>> + return 0;
>> +}
>> +
>> static int exynos_drm_create_enc_conn(struct drm_device *dev,
>> struct exynos_drm_subdrv *subdrv)
>> {
>> @@ -36,6 +72,13 @@ static int exynos_drm_create_enc_conn(struct drm_device *dev,
>> DRM_ERROR("failed to create encoder\n");
>> return -EFAULT;
>> }
>> + subdrv->encoder = encoder;
>> +
>> + if (subdrv->manager->display_ops->type == EXYNOS_DISPLAY_TYPE_LCD) {
>> + ret = exynos_drm_attach_lcd_bridge(dev, encoder);
>> + if (ret)
>> + return 0;
>> + }
>>
>> /*
>> * create and initialize a connector for this sub driver and
>> @@ -48,7 +91,6 @@ static int exynos_drm_create_enc_conn(struct drm_device *dev,
>> goto err_destroy_encoder;
>> }
>>
>> - subdrv->encoder = encoder;
>> subdrv->connector = connector;
>>
>> return 0;
>> --
>> 1.8.4
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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