| Message ID | 20230112175358.421975-2-macroalpha82@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/panel: Add Magnachip D53E6EA8966 Panel Controller | expand |
Hi, On Thu, Jan 12, 2023 at 11:53:55AM -0600, Chris Morgan wrote: > From: Chris Morgan <macromorgan@hotmail.com> > > Add helper function to find DSI host for devices where DSI panel is not > a minor of a DSI bus (such as the Samsung AMS495QA01 panel or the > official Raspberry Pi touchscreen display). > > Signed-off-by: Chris Morgan <macromorgan@hotmail.com> > Signed-off-by: Maya Matuszczyk <maccraft123mc@gmail.com> > --- > drivers/gpu/drm/drm_of.c | 70 ++++++++++++++++++++++++++++++++++++++++ > include/drm/drm_of.h | 10 ++++++ > 2 files changed, 80 insertions(+) > > diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c > index 7bbcb999bb75..6c2c97a716fe 100644 > --- a/drivers/gpu/drm/drm_of.c > +++ b/drivers/gpu/drm/drm_of.c > @@ -10,6 +10,7 @@ > #include <drm/drm_crtc.h> > #include <drm/drm_device.h> > #include <drm/drm_encoder.h> > +#include <drm/drm_mipi_dsi.h> > #include <drm/drm_of.h> > #include <drm/drm_panel.h> > > @@ -493,3 +494,72 @@ int drm_of_get_data_lanes_count_ep(const struct device_node *port, > return ret; > } > EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count_ep); > + > +#if IS_ENABLED(CONFIG_DRM_MIPI_DSI) > + > +/** > + * drm_of_get_dsi_bus - find the DSI bus for a given device > + * @dev: parent device of display (SPI, I2C) > + * @info: DSI device info to be updated with DSI node. This is optional > + * and if not needed can be NULL. > + * > + * Gets parent DSI bus for a DSI device controlled through a bus other > + * than MIPI-DCS (SPI, I2C, etc.) using the Device Tree. > + * > + * Returns pointer to mipi_dsi_host if successful, -EINVAL if the > + * request is unsupported, -EPROBE_DEFER if the DSI host is found but > + * not available, or -ENODEV otherwise. > + */ > +struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, > + struct mipi_dsi_device_info *info) > +{ > + struct mipi_dsi_host *dsi_host; > + struct device_node *endpoint, *dsi_host_node; > + > + /* > + * Get first endpoint child from device. > + */ > + endpoint = of_graph_get_next_endpoint(dev->of_node, NULL); > + if (!endpoint) > + return ERR_PTR(-ENODEV); > + > + /* > + * Follow the first endpoint to get the DSI host node. > + */ > + dsi_host_node = of_graph_get_remote_port_parent(endpoint); > + if (!dsi_host_node) > + goto error; > + > + /* > + * Get the DSI host from the DSI host node. If we get an error > + * or the return is null assume we're not ready to probe just > + * yet. Release the DSI host node since we're done with it. > + */ > + dsi_host = of_find_mipi_dsi_host_by_node(dsi_host_node); > + of_node_put(dsi_host_node); > + if (IS_ERR_OR_NULL(dsi_host)) { > + of_node_put(endpoint); > + return ERR_PTR(-EPROBE_DEFER); > + } > + > + /* > + * Set the node of the mipi_dsi_device_info to the correct node > + * and then release the endpoint node since we're done with it. > + * since this is optional, check if the info is NULL first. > + */ > + if (info) { > + info->node = of_graph_get_remote_port(endpoint); it looks to me that the info->node is actually the DSI device OF node, not its host port. Which begs the question, why should we even return it there, since there's a pretty big chance that dev->of.node == info->node, and you obviously don't care about the channel and type fields. I've had a look and node of the current users of mipi_dsi_device_register_full actually register a mipi_dsi_device_info with a node pointer set to !NULL, including the driver in this series. So, why do we care about the device info at all? > + if (IS_ERR_OR_NULL(info->node)) of_graph_get_remote_port doesn't return an error pointer. > --- a/include/drm/drm_of.h > +++ b/include/drm/drm_of.h > @@ -15,6 +15,8 @@ struct drm_encoder; > struct drm_panel; > struct drm_bridge; > struct device_node; > +struct mipi_dsi_device_info; > +struct mipi_dsi_host; > > /** > * enum drm_lvds_dual_link_pixels - Pixel order of an LVDS dual-link connection > @@ -56,6 +58,8 @@ int drm_of_get_data_lanes_count_ep(const struct device_node *port, > int port_reg, int reg, > const unsigned int min, > const unsigned int max); > +struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, > + struct mipi_dsi_device_info *info); > #else > static inline uint32_t drm_of_crtc_port_mask(struct drm_device *dev, > struct device_node *port) > @@ -127,6 +131,12 @@ drm_of_get_data_lanes_count_ep(const struct device_node *port, > { > return -EINVAL; > } > +static inline struct > +mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, > + struct mipi_dsi_device_info *info) > +{ > + return ERR_PTR(-EINVAL); > +} > #endif So it looks to me that if CONFIG_OF is defined, we'll define an external symbol declared for drm_of_get_dsi_bus, but that function will only be compiled if CONFIG_DRM_MIPI_DSI is enabled. What happens if we have CONFIG_OF but not CONFIG_DRM_MIPI_DSI? If think you need to have here something like: #ifdef IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_DRM_MIPI_DSI) struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, struct mipi_dsi_device_info *info); #else static inline struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, struct mipi_dsi_device_info *info) { return ERR_PTR(-EINVAL); } #endif Maxime
On Tue, Jan 17, 2023 at 05:58:19PM +0100, Maxime Ripard wrote: > Hi, > > On Thu, Jan 12, 2023 at 11:53:55AM -0600, Chris Morgan wrote: > > From: Chris Morgan <macromorgan@hotmail.com> > > > > Add helper function to find DSI host for devices where DSI panel is not > > a minor of a DSI bus (such as the Samsung AMS495QA01 panel or the > > official Raspberry Pi touchscreen display). > > > > Signed-off-by: Chris Morgan <macromorgan@hotmail.com> > > Signed-off-by: Maya Matuszczyk <maccraft123mc@gmail.com> > > --- > > drivers/gpu/drm/drm_of.c | 70 ++++++++++++++++++++++++++++++++++++++++ > > include/drm/drm_of.h | 10 ++++++ > > 2 files changed, 80 insertions(+) > > > > diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c > > index 7bbcb999bb75..6c2c97a716fe 100644 > > --- a/drivers/gpu/drm/drm_of.c > > +++ b/drivers/gpu/drm/drm_of.c > > @@ -10,6 +10,7 @@ > > #include <drm/drm_crtc.h> > > #include <drm/drm_device.h> > > #include <drm/drm_encoder.h> > > +#include <drm/drm_mipi_dsi.h> > > #include <drm/drm_of.h> > > #include <drm/drm_panel.h> > > > > @@ -493,3 +494,72 @@ int drm_of_get_data_lanes_count_ep(const struct device_node *port, > > return ret; > > } > > EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count_ep); > > + > > +#if IS_ENABLED(CONFIG_DRM_MIPI_DSI) > > + > > +/** > > + * drm_of_get_dsi_bus - find the DSI bus for a given device > > + * @dev: parent device of display (SPI, I2C) > > + * @info: DSI device info to be updated with DSI node. This is optional > > + * and if not needed can be NULL. > > + * > > + * Gets parent DSI bus for a DSI device controlled through a bus other > > + * than MIPI-DCS (SPI, I2C, etc.) using the Device Tree. > > + * > > + * Returns pointer to mipi_dsi_host if successful, -EINVAL if the > > + * request is unsupported, -EPROBE_DEFER if the DSI host is found but > > + * not available, or -ENODEV otherwise. > > + */ > > +struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, > > + struct mipi_dsi_device_info *info) > > +{ > > + struct mipi_dsi_host *dsi_host; > > + struct device_node *endpoint, *dsi_host_node; > > + > > + /* > > + * Get first endpoint child from device. > > + */ > > + endpoint = of_graph_get_next_endpoint(dev->of_node, NULL); > > + if (!endpoint) > > + return ERR_PTR(-ENODEV); > > + > > + /* > > + * Follow the first endpoint to get the DSI host node. > > + */ > > + dsi_host_node = of_graph_get_remote_port_parent(endpoint); > > + if (!dsi_host_node) > > + goto error; > > + > > + /* > > + * Get the DSI host from the DSI host node. If we get an error > > + * or the return is null assume we're not ready to probe just > > + * yet. Release the DSI host node since we're done with it. > > + */ > > + dsi_host = of_find_mipi_dsi_host_by_node(dsi_host_node); > > + of_node_put(dsi_host_node); > > + if (IS_ERR_OR_NULL(dsi_host)) { > > + of_node_put(endpoint); > > + return ERR_PTR(-EPROBE_DEFER); > > + } > > + > > + /* > > + * Set the node of the mipi_dsi_device_info to the correct node > > + * and then release the endpoint node since we're done with it. > > + * since this is optional, check if the info is NULL first. > > + */ > > + if (info) { > > + info->node = of_graph_get_remote_port(endpoint); > > it looks to me that the info->node is actually the DSI device OF node, > not its host port. Which begs the question, why should we even return it > there, since there's a pretty big chance that dev->of.node == > info->node, and you obviously don't care about the channel and type fields. > > I've had a look and node of the current users of > mipi_dsi_device_register_full actually register a mipi_dsi_device_info > with a node pointer set to !NULL, including the driver in this series. > > So, why do we care about the device info at all? > I honestly thought it might be useful, but I can try without it. > > + if (IS_ERR_OR_NULL(info->node)) > > of_graph_get_remote_port doesn't return an error pointer. > > > --- a/include/drm/drm_of.h > > +++ b/include/drm/drm_of.h > > @@ -15,6 +15,8 @@ struct drm_encoder; > > struct drm_panel; > > struct drm_bridge; > > struct device_node; > > +struct mipi_dsi_device_info; > > +struct mipi_dsi_host; > > > > /** > > * enum drm_lvds_dual_link_pixels - Pixel order of an LVDS dual-link connection > > @@ -56,6 +58,8 @@ int drm_of_get_data_lanes_count_ep(const struct device_node *port, > > int port_reg, int reg, > > const unsigned int min, > > const unsigned int max); > > +struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, > > + struct mipi_dsi_device_info *info); > > #else > > static inline uint32_t drm_of_crtc_port_mask(struct drm_device *dev, > > struct device_node *port) > > @@ -127,6 +131,12 @@ drm_of_get_data_lanes_count_ep(const struct device_node *port, > > { > > return -EINVAL; > > } > > +static inline struct > > +mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, > > + struct mipi_dsi_device_info *info) > > +{ > > + return ERR_PTR(-EINVAL); > > +} > > #endif > > So it looks to me that if CONFIG_OF is defined, we'll define an external > symbol declared for drm_of_get_dsi_bus, but that function will only be > compiled if CONFIG_DRM_MIPI_DSI is enabled. > > What happens if we have CONFIG_OF but not CONFIG_DRM_MIPI_DSI? > Will do, thank you. > If think you need to have here something like: > > #ifdef IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_DRM_MIPI_DSI) > struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, > struct mipi_dsi_device_info *info); > #else > static inline struct > mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, > struct mipi_dsi_device_info *info) > { > return ERR_PTR(-EINVAL); > } > #endif > > Maxime
On Tue, Jan 17, 2023 at 01:12:39PM -0600, Chris Morgan wrote: > On Tue, Jan 17, 2023 at 05:58:19PM +0100, Maxime Ripard wrote: > > Hi, > > > > On Thu, Jan 12, 2023 at 11:53:55AM -0600, Chris Morgan wrote: > > > From: Chris Morgan <macromorgan@hotmail.com> > > > > > > Add helper function to find DSI host for devices where DSI panel is not > > > a minor of a DSI bus (such as the Samsung AMS495QA01 panel or the > > > official Raspberry Pi touchscreen display). > > > > > > Signed-off-by: Chris Morgan <macromorgan@hotmail.com> > > > Signed-off-by: Maya Matuszczyk <maccraft123mc@gmail.com> > > > --- > > > drivers/gpu/drm/drm_of.c | 70 ++++++++++++++++++++++++++++++++++++++++ > > > include/drm/drm_of.h | 10 ++++++ > > > 2 files changed, 80 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c > > > index 7bbcb999bb75..6c2c97a716fe 100644 > > > --- a/drivers/gpu/drm/drm_of.c > > > +++ b/drivers/gpu/drm/drm_of.c > > > @@ -10,6 +10,7 @@ > > > #include <drm/drm_crtc.h> > > > #include <drm/drm_device.h> > > > #include <drm/drm_encoder.h> > > > +#include <drm/drm_mipi_dsi.h> > > > #include <drm/drm_of.h> > > > #include <drm/drm_panel.h> > > > > > > @@ -493,3 +494,72 @@ int drm_of_get_data_lanes_count_ep(const struct device_node *port, > > > return ret; > > > } > > > EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count_ep); > > > + > > > +#if IS_ENABLED(CONFIG_DRM_MIPI_DSI) > > > + > > > +/** > > > + * drm_of_get_dsi_bus - find the DSI bus for a given device > > > + * @dev: parent device of display (SPI, I2C) > > > + * @info: DSI device info to be updated with DSI node. This is optional > > > + * and if not needed can be NULL. > > > + * > > > + * Gets parent DSI bus for a DSI device controlled through a bus other > > > + * than MIPI-DCS (SPI, I2C, etc.) using the Device Tree. > > > + * > > > + * Returns pointer to mipi_dsi_host if successful, -EINVAL if the > > > + * request is unsupported, -EPROBE_DEFER if the DSI host is found but > > > + * not available, or -ENODEV otherwise. > > > + */ > > > +struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, > > > + struct mipi_dsi_device_info *info) > > > +{ > > > + struct mipi_dsi_host *dsi_host; > > > + struct device_node *endpoint, *dsi_host_node; > > > + > > > + /* > > > + * Get first endpoint child from device. > > > + */ > > > + endpoint = of_graph_get_next_endpoint(dev->of_node, NULL); > > > + if (!endpoint) > > > + return ERR_PTR(-ENODEV); > > > + > > > + /* > > > + * Follow the first endpoint to get the DSI host node. > > > + */ > > > + dsi_host_node = of_graph_get_remote_port_parent(endpoint); > > > + if (!dsi_host_node) > > > + goto error; > > > + > > > + /* > > > + * Get the DSI host from the DSI host node. If we get an error > > > + * or the return is null assume we're not ready to probe just > > > + * yet. Release the DSI host node since we're done with it. > > > + */ > > > + dsi_host = of_find_mipi_dsi_host_by_node(dsi_host_node); > > > + of_node_put(dsi_host_node); > > > + if (IS_ERR_OR_NULL(dsi_host)) { > > > + of_node_put(endpoint); > > > + return ERR_PTR(-EPROBE_DEFER); > > > + } > > > + > > > + /* > > > + * Set the node of the mipi_dsi_device_info to the correct node > > > + * and then release the endpoint node since we're done with it. > > > + * since this is optional, check if the info is NULL first. > > > + */ > > > + if (info) { > > > + info->node = of_graph_get_remote_port(endpoint); > > > > it looks to me that the info->node is actually the DSI device OF node, > > not its host port. Which begs the question, why should we even return it > > there, since there's a pretty big chance that dev->of.node == > > info->node, and you obviously don't care about the channel and type fields. > > > > I've had a look and node of the current users of > > mipi_dsi_device_register_full actually register a mipi_dsi_device_info > > with a node pointer set to !NULL, including the driver in this series. > > > > So, why do we care about the device info at all? > > I honestly thought it might be useful, but I can try without it. It might tbh, but it doesn't look like you use it in your driver. You have: struct mipi_dsi_device_info info = { .type = "d53e6ea8966", .channel = 0, .node = NULL, }; ... // info.node is NULL so far dsi_host = drm_of_get_dsi_bus(dev, &info); ... // info.node has been filled to the port node by drm_of_get_dsi_bus() db->dsi_dev = devm_mipi_dsi_device_register_full(dev, dsi_host, &info); // db->dsi_dev.dev.of_node is now set to the port node But if we grep through drm_mipi_dsi.c, we can see that the of_node is only really useful if we're using of_find_mipi_dsi_device_by_node, and it looks like you don't. So nothing uses info->node, which also explains why not reporting the proper node has been working. Looking more into the code, it really looks to me that info->node should be equal to the your panel device tree node, that's what of_mipi_dsi_device_add does at least. if info->node == dev->of_node, and if info->node is the only thing filled by drm_of_get_dsi_bus(), then it doesn't need to fill it at all because it's already accessible easily to the caller (and even more easily than to the callee). So yeah, until we have a real-world need to retrieve the info function I think we should leave it aside for now, and we can always change the API later if we need to. Maxime
diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c index 7bbcb999bb75..6c2c97a716fe 100644 --- a/drivers/gpu/drm/drm_of.c +++ b/drivers/gpu/drm/drm_of.c @@ -10,6 +10,7 @@ #include <drm/drm_crtc.h> #include <drm/drm_device.h> #include <drm/drm_encoder.h> +#include <drm/drm_mipi_dsi.h> #include <drm/drm_of.h> #include <drm/drm_panel.h> @@ -493,3 +494,72 @@ int drm_of_get_data_lanes_count_ep(const struct device_node *port, return ret; } EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count_ep); + +#if IS_ENABLED(CONFIG_DRM_MIPI_DSI) + +/** + * drm_of_get_dsi_bus - find the DSI bus for a given device + * @dev: parent device of display (SPI, I2C) + * @info: DSI device info to be updated with DSI node. This is optional + * and if not needed can be NULL. + * + * Gets parent DSI bus for a DSI device controlled through a bus other + * than MIPI-DCS (SPI, I2C, etc.) using the Device Tree. + * + * Returns pointer to mipi_dsi_host if successful, -EINVAL if the + * request is unsupported, -EPROBE_DEFER if the DSI host is found but + * not available, or -ENODEV otherwise. + */ +struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, + struct mipi_dsi_device_info *info) +{ + struct mipi_dsi_host *dsi_host; + struct device_node *endpoint, *dsi_host_node; + + /* + * Get first endpoint child from device. + */ + endpoint = of_graph_get_next_endpoint(dev->of_node, NULL); + if (!endpoint) + return ERR_PTR(-ENODEV); + + /* + * Follow the first endpoint to get the DSI host node. + */ + dsi_host_node = of_graph_get_remote_port_parent(endpoint); + if (!dsi_host_node) + goto error; + + /* + * Get the DSI host from the DSI host node. If we get an error + * or the return is null assume we're not ready to probe just + * yet. Release the DSI host node since we're done with it. + */ + dsi_host = of_find_mipi_dsi_host_by_node(dsi_host_node); + of_node_put(dsi_host_node); + if (IS_ERR_OR_NULL(dsi_host)) { + of_node_put(endpoint); + return ERR_PTR(-EPROBE_DEFER); + } + + /* + * Set the node of the mipi_dsi_device_info to the correct node + * and then release the endpoint node since we're done with it. + * since this is optional, check if the info is NULL first. + */ + if (info) { + info->node = of_graph_get_remote_port(endpoint); + if (IS_ERR_OR_NULL(info->node)) + goto error; + } + + of_node_put(endpoint); + return dsi_host; + +error: + of_node_put(endpoint); + return ERR_PTR(-ENODEV); +} +EXPORT_SYMBOL_GPL(drm_of_get_dsi_bus); + +#endif /* CONFIG_DRM_MIPI_DSI */ diff --git a/include/drm/drm_of.h b/include/drm/drm_of.h index 10ab58c40746..705ea2caa494 100644 --- a/include/drm/drm_of.h +++ b/include/drm/drm_of.h @@ -15,6 +15,8 @@ struct drm_encoder; struct drm_panel; struct drm_bridge; struct device_node; +struct mipi_dsi_device_info; +struct mipi_dsi_host; /** * enum drm_lvds_dual_link_pixels - Pixel order of an LVDS dual-link connection @@ -56,6 +58,8 @@ int drm_of_get_data_lanes_count_ep(const struct device_node *port, int port_reg, int reg, const unsigned int min, const unsigned int max); +struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, + struct mipi_dsi_device_info *info); #else static inline uint32_t drm_of_crtc_port_mask(struct drm_device *dev, struct device_node *port) @@ -127,6 +131,12 @@ drm_of_get_data_lanes_count_ep(const struct device_node *port, { return -EINVAL; } +static inline struct +mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev, + struct mipi_dsi_device_info *info) +{ + return ERR_PTR(-EINVAL); +} #endif /*