diff mbox series

[V7,1/4] drm: of: Add drm_of_get_dsi_bus helper function

Message ID 20230103190707.104595-2-macroalpha82@gmail.com (mailing list archive)
State New, archived
Headers show
Series drm/panel: Add Magnachip D53E6EA8966 Panel Controller | expand

Commit Message

Chris Morgan Jan. 3, 2023, 7:07 p.m. UTC 
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>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/gpu/drm/drm_of.c | 62 ++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_of.h     | 11 +++++++
 2 files changed, 73 insertions(+)

Comments

Sam Ravnborg Jan. 3, 2023, 7:38 p.m. UTC | #1 
Hi Chris.

On Tue, Jan 03, 2023 at 01:07:04PM -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>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  drivers/gpu/drm/drm_of.c | 62 ++++++++++++++++++++++++++++++++++++++++
>  include/drm/drm_of.h     | 11 +++++++
>  2 files changed, 73 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
> index 7bbcb999bb75..7d89ac164069 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 +494,64 @@ 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);
> +
> +/**
> + * drm_of_get_dsi_bus - find the DSI bus for a given device
> + * @dev: parent device of display (SPI, I2C)
> + * @dsi_host: DSI host to be populated
> + * @info: DSI device info to be updated with correct DSI node
> + *
> + * Given a panel device parented to a non-DSI device, follow the
> + * devicetree to find the correct DSI host node and populate the
> + * dsi_host with the correct host and info with the correct node.

I think you need and empty line before Returns ...
This is what others does in the same file, so for consistency please add
it.

With this detail fixed:
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>

> + * Returns zero if successful, -EPROBE_DEFER if the DSI host is
> + * found but not available, or -ENODEV otherwise.
> + */
> +int drm_of_get_dsi_bus(struct device *dev,
> +			      struct mipi_dsi_host **dsi_host,
> +			      struct mipi_dsi_device_info *info)
> +{
> +	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 -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 -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.
> +	 */
> +	info->node = of_graph_get_remote_port(endpoint);
> +	if (IS_ERR_OR_NULL(info->node))
> +		goto error;
> +
> +	of_node_put(endpoint);
> +	return 0;
> +
> +error:
> +	of_node_put(endpoint);
> +	return -ENODEV;
> +}
> +EXPORT_SYMBOL_GPL(drm_of_get_dsi_bus);
> diff --git a/include/drm/drm_of.h b/include/drm/drm_of.h
> index 10ab58c40746..e27061b02315 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 +58,9 @@ 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);
> +int drm_of_get_dsi_bus(struct device *dev,
> +		       struct mipi_dsi_host **dsi_host,
> +		       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 +132,12 @@ drm_of_get_data_lanes_count_ep(const struct device_node *port,
>  {
>  	return -EINVAL;
>  }
> +static int drm_of_get_dsi_bus(struct device *dev,
> +			      struct mipi_dsi_host **dsi_host,
> +			      struct mipi_dsi_device_info *info)
> +{
> +	return -EINVAL;
> +}
>  #endif
>  
>  /*
> -- 
> 2.34.1
Maxime Ripard Jan. 4, 2023, 12:40 p.m. UTC | #2 
Hi,

On Tue, Jan 03, 2023 at 01:07:04PM -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>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  drivers/gpu/drm/drm_of.c | 62 ++++++++++++++++++++++++++++++++++++++++
>  include/drm/drm_of.h     | 11 +++++++
>  2 files changed, 73 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
> index 7bbcb999bb75..7d89ac164069 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 +494,64 @@ 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);
> +
> +/**
> + * drm_of_get_dsi_bus - find the DSI bus for a given device
> + * @dev: parent device of display (SPI, I2C)
> + * @dsi_host: DSI host to be populated
> + * @info: DSI device info to be updated with correct DSI node

Why aren't we returning the dsi_host through an ERR_PTR? All the DRM
accessors with get return the pointer directly, I'd rather stick to
that.

> + * Given a panel device parented to a non-DSI device, follow the
> + * devicetree to find the correct DSI host node and populate the
> + * dsi_host with the correct host and info with the correct node.

I think we could make that a bit clearer using something like:

Gets parent DSI bus for a DSI device controlled through a bus other than
MIPI-DCS (SPI, I2C, etc.) using the Device Tree.

> + * Returns zero if successful, -EPROBE_DEFER if the DSI host is
> + * found but not available, or -ENODEV otherwise.
> + */

> +int drm_of_get_dsi_bus(struct device *dev,
> +			      struct mipi_dsi_host **dsi_host,
> +			      struct mipi_dsi_device_info *info)

The arguments are not aligned.

Maxime
kernel test robot Jan. 4, 2023, 11:14 p.m. UTC | #3 
Hi Chris,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on rockchip/for-next]
[also build test ERROR on drm/drm-next drm-intel/for-linux-next drm-intel/for-linux-next-fixes drm-tip/drm-tip drm-exynos/exynos-drm-next linus/master v6.2-rc2 next-20221226]
[cannot apply to drm-misc/drm-misc-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Chris-Morgan/drm-of-Add-drm_of_get_dsi_bus-helper-function/20230104-030847
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip.git for-next
patch link:    https://lore.kernel.org/r/20230103190707.104595-2-macroalpha82%40gmail.com
patch subject: [PATCH V7 1/4] drm: of: Add drm_of_get_dsi_bus helper function
config: riscv-rv32_defconfig
compiler: riscv32-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/bb4fe9a62dc7ba531e6ddf312873562cbfd1fe98
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Chris-Morgan/drm-of-Add-drm_of_get_dsi_bus-helper-function/20230104-030847
        git checkout bb4fe9a62dc7ba531e6ddf312873562cbfd1fe98
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=riscv olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "of_find_mipi_dsi_host_by_node" [drivers/gpu/drm/drm.ko] undefined!
kernel test robot Jan. 5, 2023, 1:25 a.m. UTC | #4 
Hi Chris,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on rockchip/for-next]
[also build test ERROR on drm/drm-next drm-intel/for-linux-next drm-intel/for-linux-next-fixes drm-tip/drm-tip drm-exynos/exynos-drm-next linus/master v6.2-rc2 next-20221226]
[cannot apply to drm-misc/drm-misc-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Chris-Morgan/drm-of-Add-drm_of_get_dsi_bus-helper-function/20230104-030847
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip.git for-next
patch link:    https://lore.kernel.org/r/20230103190707.104595-2-macroalpha82%40gmail.com
patch subject: [PATCH V7 1/4] drm: of: Add drm_of_get_dsi_bus helper function
config: arc-nsimosci_hs_smp_defconfig
compiler: arc-elf-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/bb4fe9a62dc7ba531e6ddf312873562cbfd1fe98
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Chris-Morgan/drm-of-Add-drm_of_get_dsi_bus-helper-function/20230104-030847
        git checkout bb4fe9a62dc7ba531e6ddf312873562cbfd1fe98
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   arc-elf-ld: drivers/gpu/drm/drm_of.o: in function `drm_of_get_dsi_bus':
   drm_of.c:(.text+0x326): undefined reference to `of_find_mipi_dsi_host_by_node'
>> arc-elf-ld: drm_of.c:(.text+0x326): undefined reference to `of_find_mipi_dsi_host_by_node'
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
index 7bbcb999bb75..7d89ac164069 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 +494,64 @@  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);
+
+/**
+ * drm_of_get_dsi_bus - find the DSI bus for a given device
+ * @dev: parent device of display (SPI, I2C)
+ * @dsi_host: DSI host to be populated
+ * @info: DSI device info to be updated with correct DSI node
+ *
+ * Given a panel device parented to a non-DSI device, follow the
+ * devicetree to find the correct DSI host node and populate the
+ * dsi_host with the correct host and info with the correct node.
+ * Returns zero if successful, -EPROBE_DEFER if the DSI host is
+ * found but not available, or -ENODEV otherwise.
+ */
+int drm_of_get_dsi_bus(struct device *dev,
+			      struct mipi_dsi_host **dsi_host,
+			      struct mipi_dsi_device_info *info)
+{
+	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 -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 -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.
+	 */
+	info->node = of_graph_get_remote_port(endpoint);
+	if (IS_ERR_OR_NULL(info->node))
+		goto error;
+
+	of_node_put(endpoint);
+	return 0;
+
+error:
+	of_node_put(endpoint);
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(drm_of_get_dsi_bus);
diff --git a/include/drm/drm_of.h b/include/drm/drm_of.h
index 10ab58c40746..e27061b02315 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 +58,9 @@  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);
+int drm_of_get_dsi_bus(struct device *dev,
+		       struct mipi_dsi_host **dsi_host,
+		       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 +132,12 @@  drm_of_get_data_lanes_count_ep(const struct device_node *port,
 {
 	return -EINVAL;
 }
+static int drm_of_get_dsi_bus(struct device *dev,
+			      struct mipi_dsi_host **dsi_host,
+			      struct mipi_dsi_device_info *info)
+{
+	return -EINVAL;
+}
 #endif
 
 /*