Hi,
On 08/19/2015 01:40 PM, Andrzej Hajda wrote:
On 06/30/2015 07:24 AM, Archit Taneja wrote:
We can have devices where the data bus is MIPI DSI, but the control bus is something else (i2c, spi etc). A typical example is i2c controlled encoder bridge chips.
Such devices too require passing DSI specific parameters (number of data lanes, DSI mode flags, color format etc) to their DSI host. For a device that isn't 'mipi_dsi_device', there is no way of passing such parameters.
Provide the option of creating a dummy DSI device. The main purpose of this would be to attach to a DSI host by calling mipi_dsi_attach, and pass DSI params.
Create mipi_dsi_new_dummy for creating a dummy dsi device. The driver calling this needs to be aware of the mipi_dsi_host it wants to attach to, and also the DSI virtual channel the DSI device intends to use.
Signed-off-by: Archit Taneja architt@codeaurora.org
drivers/gpu/drm/drm_mipi_dsi.c | 78 ++++++++++++++++++++++++++++++++++++++++-- include/drm/drm_mipi_dsi.h | 2 ++ 2 files changed, 78 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index 2d5ca8ee..9bfe215 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -47,7 +47,14 @@
static int mipi_dsi_device_match(struct device *dev, struct device_driver *drv) {
- return of_driver_match_device(dev, drv);
- if (of_driver_match_device(dev, drv))
return 1;- if (!strcmp(drv->name, "mipi_dsi_dummy") &&
strstr(dev_name(dev), "dummy_dev"))return 1;Is this kind of fuzzy matching used in other dummy devs? It looks little bit scary. You can at least replace
strstr(dev_name(dev), "dummy_dev"))
with
strstr(dev_name(dev), ".dummy_dev."))
Anyway, currently it should not break anything, am I right?
I took i2c's dummy dev creation as reference. The i2c_driver struct has an id_table param, that allows the match function (i2c_device_match) to not have a special case to check for a dummy device.
We could a 'id_table' entry in mipi_dsi_driver, and a 'name' entry in mipi_dsi_device. But that would be a bit of an overkill just to support dummy devices.
I could make the check more thorough by adding a func which does something similar to 'i2c_verify_client', but I think we would still need the above string.
I will change "dummy_dev" to ".dummy_dev.". I grepped the kernel for devices named "dummy_dev", but didn't find anything as such, so it shouldn't really break anything.
return 0; }
static const struct dev_pm_ops mipi_dsi_device_pm_ops = {
@@ -171,6 +178,67 @@ of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node) return dsi; }
+static int dummy_probe(struct mipi_dsi_device *dsi) +{
- return 0;
+}
+static int dummy_remove(struct mipi_dsi_device *dsi) +{
- return 0;
+}
+static void dummy_shutdown(struct mipi_dsi_device *dsi) +{ +}
I suppose these callbacks are optional, so you can omit them.
Right. I will remove these.
Thanks for the review.
Archit