| Message ID | 20230322104639.221402-4-treapking@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Register Type-C mode-switch in DP bridge endpoints | expand |
On Wed, Mar 22, 2023 at 06:46:32PM +0800, Pin-yen Lin wrote: > Add helpers to register and unregister Type-C "switches" for bridges > capable of switching their output between two downstream devices. > > The helper registers USB Type-C mode switches when the "mode-switch" > and the "reg" properties are available in Device Tree. ... > +config DRM_DISPLAY_DP_TYPEC_HELPER > + bool > + default y def_bool y > + depends on DRM_DISPLAY_HELPER > + depends on DRM_DISPLAY_HELPER=TYPEC || TYPEC=y > + help > + DRM display helpers for USB Type-C Displayport Alternate mode. Hmm... Dunno if this help is enough. ... > + snprintf(name, sizeof(name), "%pfwP-%u", fwnode, port_num); Would it be possible to have a dup in name and would it be a problem if so? ... > +/** > + * drm_dp_register_typec_switches() - register Type-C switches > + * @dev: Device that registers Type-C switches > + * @port: Device node for the switch > + * @switch_desc: A Type-C switch descriptor > + * @data: Private data for the switches > + * @mux_set: Callback function for typec_mux_set > + * > + * This function registers USB Type-C switches for DP bridges that can switch > + * the output signal between their output pins. This function uses devm_kcalloc > + * to allocate memory, so it is expected to only call this in the driver probe > + * functions. > + * > + * Currently only mode switches are implemented, and the function assumes the > + * given @port device node has endpoints with "mode-switch" property. > + * The port number is determined by the "reg" property of the endpoint. `kernel-doc -v ...` should complain on absence of "Return" section. > + */ ... > + switch_desc->typec_ports = devm_kcalloc(dev, switch_desc->num_typec_switches, > + sizeof(struct drm_dp_typec_port_data), sizeof(*switch_desc_typec_ports), ? > + GFP_KERNEL); > + if (!switch_desc->typec_ports) > + return -ENOMEM; ... > +#ifdef CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER Ah, maybe this should use IS_REACHABLE() ? > +void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc); > +int drm_dp_register_typec_switches(struct device *dev, struct fwnode_handle *port, > + struct drm_dp_typec_switch_desc *switch_desc, > + void *data, typec_mux_set_fn_t mux_set); > +#else > +static inline void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc) > +{ > +} > +static inline int drm_dp_register_typec_switches( > + struct device *dev, struct fwnode_handle *port, > + struct drm_dp_typec_switch_desc *switch_desc, void *data, > + typec_mux_set_fn_t mux_set) > +{ > + return -EOPNOTSUPP; > +} > +#endif
On Wed, 22 Mar 2023, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > On Wed, Mar 22, 2023 at 06:46:32PM +0800, Pin-yen Lin wrote: >> +#ifdef CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER > > Ah, maybe this should use IS_REACHABLE() ? Personally, I think IS_REACHABLE() is a build-time band-aid solution to a problem that should be solved in Kconfig. :p I think it always means there's a configuration combo that shouldn't exist, and it's a surprise to the user when they've configured something, Kconfig has deemed it a valid configuration, but they don't get the feature they want. As a user, how would they even debug that case? Double check configs, don't see anything wrong. BR, Jani.
On Wed, 22 Mar 2023 at 12:47, Pin-yen Lin <treapking@chromium.org> wrote: > > Add helpers to register and unregister Type-C "switches" for bridges > capable of switching their output between two downstream devices. > > The helper registers USB Type-C mode switches when the "mode-switch" > and the "reg" properties are available in Device Tree. > > Signed-off-by: Pin-yen Lin <treapking@chromium.org> > > --- > > Changes in v14: > - Introduce a new Kconfig becuase it didn't build when CONFIG_TYPEC=m > - Add comments about devm_* usage > - Fix style issues > > Changes in v13: > - Add typec_mode_switch_node_count helper > - Fix style issues > > Changes in v12: > - Add fwnode_for_each_typec_mode_switch macro > - Remove a duplicated dmesg in the helper > - Used IS_REACHABLE instead to guard the function signatures > > Changes in v11: > - Use fwnode helpers instead of DT > - Moved the helpers to a new file > - Use "reg" instead of "data-lanes" to determine the port number > - Dropped collected tags due to new changes > > Changes in v10: > - Collected Reviewed-by and Tested-by tags > - Replaced "void *" with "typec_mux_set_fn_t" for mux_set callbacks > - Print out the node name when errors on parsing DT > - Use dev_dbg instead of dev_warn when no Type-C switch nodes available > - Made the return path of drm_dp_register_mode_switch clearer > > Changes in v8: > - Fixed the build issue when CONFIG_TYPEC=m > - Fixed some style issues > > Changes in v7: > - Extracted the common codes to a helper function > - New in v7 > > drivers/gpu/drm/display/Kconfig | 8 ++ > drivers/gpu/drm/display/Makefile | 2 + > drivers/gpu/drm/display/drm_dp_typec_helper.c | 105 ++++++++++++++++++ > include/drm/display/drm_dp_helper.h | 46 ++++++++ > 4 files changed, 161 insertions(+) > create mode 100644 drivers/gpu/drm/display/drm_dp_typec_helper.c > > diff --git a/drivers/gpu/drm/display/Kconfig b/drivers/gpu/drm/display/Kconfig > index 09712b88a5b8..d61076947a1c 100644 > --- a/drivers/gpu/drm/display/Kconfig > +++ b/drivers/gpu/drm/display/Kconfig > @@ -29,6 +29,14 @@ config DRM_DISPLAY_HDMI_HELPER > help > DRM display helpers for HDMI. > > +config DRM_DISPLAY_DP_TYPEC_HELPER > + bool > + default y > + depends on DRM_DISPLAY_HELPER > + depends on DRM_DISPLAY_HELPER=TYPEC || TYPEC=y If it is a select'able option, it doesn't make sense to use "depends" here. Select will override depends. > + help > + DRM display helpers for USB Type-C Displayport Alternate mode. > + > config DRM_DP_AUX_CHARDEV > bool "DRM DP AUX Interface" > depends on DRM && DRM_DISPLAY_HELPER > diff --git a/drivers/gpu/drm/display/Makefile b/drivers/gpu/drm/display/Makefile > index 17ac4a1006a8..2202a6aea38e 100644 > --- a/drivers/gpu/drm/display/Makefile > +++ b/drivers/gpu/drm/display/Makefile > @@ -8,6 +8,8 @@ drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_HELPER) += \ > drm_dp_helper.o \ > drm_dp_mst_topology.o \ > drm_dsc_helper.o > +drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER) += \ > + drm_dp_typec_helper.o > drm_display_helper-$(CONFIG_DRM_DISPLAY_HDCP_HELPER) += drm_hdcp_helper.o > drm_display_helper-$(CONFIG_DRM_DISPLAY_HDMI_HELPER) += \ > drm_hdmi_helper.o \ > diff --git a/drivers/gpu/drm/display/drm_dp_typec_helper.c b/drivers/gpu/drm/display/drm_dp_typec_helper.c > new file mode 100644 > index 000000000000..1562a9ccdaf2 > --- /dev/null > +++ b/drivers/gpu/drm/display/drm_dp_typec_helper.c > @@ -0,0 +1,105 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#include <linux/usb/typec_mux.h> > +#include <drm/display/drm_dp_helper.h> > + > +static int drm_dp_register_mode_switch(struct device *dev, > + struct fwnode_handle *fwnode, > + struct drm_dp_typec_switch_desc *switch_desc, > + void *data, typec_mux_set_fn_t mux_set) > +{ > + struct drm_dp_typec_port_data *port_data; > + struct typec_mux_desc mux_desc = {}; > + char name[32]; Why 32? > + u32 port_num; > + int ret; > + > + ret = fwnode_property_read_u32(fwnode, "reg", &port_num); > + if (ret) { > + dev_err(dev, "Failed to read reg property: %d\n", ret); > + return ret; > + } > + > + port_data = &switch_desc->typec_ports[port_num]; > + port_data->data = data; > + port_data->port_num = port_num; > + port_data->fwnode = fwnode; > + mux_desc.fwnode = fwnode; > + mux_desc.drvdata = port_data; > + snprintf(name, sizeof(name), "%pfwP-%u", fwnode, port_num); I think it makes more sense to use dev_name here instead of fwnode. > + mux_desc.name = name; > + mux_desc.set = mux_set; > + > + port_data->typec_mux = typec_mux_register(dev, &mux_desc); > + ret = PTR_ERR_OR_ZERO(port_data->typec_mux); > + if (ret) > + dev_err(dev, "Mode switch register for port %d failed: %d\n", > + port_num, ret); > + > + return ret; > +} > + > +/** > + * drm_dp_register_typec_switches() - register Type-C switches > + * @dev: Device that registers Type-C switches > + * @port: Device node for the switch > + * @switch_desc: A Type-C switch descriptor > + * @data: Private data for the switches > + * @mux_set: Callback function for typec_mux_set > + * > + * This function registers USB Type-C switches for DP bridges that can switch > + * the output signal between their output pins. This function uses devm_kcalloc > + * to allocate memory, so it is expected to only call this in the driver probe > + * functions. > + * > + * Currently only mode switches are implemented, and the function assumes the > + * given @port device node has endpoints with "mode-switch" property. > + * The port number is determined by the "reg" property of the endpoint. > + */ > +int drm_dp_register_typec_switches(struct device *dev, struct fwnode_handle *port, > + struct drm_dp_typec_switch_desc *switch_desc, > + void *data, typec_mux_set_fn_t mux_set) > +{ > + struct fwnode_handle *sw; > + int ret; > + > + switch_desc->num_typec_switches = typec_mode_switch_node_count(port); > + if (!switch_desc->num_typec_switches) { > + dev_dbg(dev, "No Type-C switches node found\n"); > + return 0; > + } > + > + switch_desc->typec_ports = devm_kcalloc(dev, switch_desc->num_typec_switches, > + sizeof(struct drm_dp_typec_port_data), > + GFP_KERNEL); > + if (!switch_desc->typec_ports) > + return -ENOMEM; > + > + /* Register switches for each connector. */ > + for_each_typec_mode_switch_node(port, sw) { > + ret = drm_dp_register_mode_switch(dev, sw, switch_desc, data, mux_set); > + if (ret) > + goto err_unregister_typec_switches; > + } > + > + return 0; > + > +err_unregister_typec_switches: > + fwnode_handle_put(sw); > + drm_dp_unregister_typec_switches(switch_desc); > + return ret; > +} > +EXPORT_SYMBOL(drm_dp_register_typec_switches); > + > +/** > + * drm_dp_unregister_typec_switches() - unregister Type-C switches > + * @switch_desc: A Type-C switch descriptor > + */ > +void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc) > +{ > + unsigned int i; > + > + for (i = 0; i < switch_desc->num_typec_switches; i++) > + typec_mux_unregister(switch_desc->typec_ports[i].typec_mux); > +} > +EXPORT_SYMBOL(drm_dp_unregister_typec_switches); > diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h > index ab55453f2d2c..0fe56586d7bc 100644 > --- a/include/drm/display/drm_dp_helper.h > +++ b/include/drm/display/drm_dp_helper.h > @@ -25,6 +25,7 @@ > > #include <linux/delay.h> > #include <linux/i2c.h> > +#include <linux/usb/typec_mux.h> > > #include <drm/display/drm_dp.h> > #include <drm/drm_connector.h> > @@ -763,4 +764,49 @@ bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZ > const u8 port_cap[4], u8 color_spc); > int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc); > > +struct drm_dp_typec_port_data { > + struct typec_mux_dev *typec_mux; > + int port_num; > + struct fwnode_handle *fwnode; > + void *data; > +}; > + > +struct drm_dp_typec_switch_desc { > + int num_typec_switches; > + struct drm_dp_typec_port_data *typec_ports; > +}; > + > +#define for_each_typec_mode_switch_node(port, sw) \ > + fwnode_for_each_child_node((port), (sw)) \ > + for_each_if(fwnode_property_present((sw), "mode-switch")) > + > +static inline unsigned int typec_mode_switch_node_count(struct fwnode_handle *port) > +{ > + struct fwnode_handle *sw; > + unsigned int count = 0; > + > + for_each_typec_mode_switch_node(port, sw) > + count++; > + > + return count; > +} > + > +#ifdef CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER > +void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc); > +int drm_dp_register_typec_switches(struct device *dev, struct fwnode_handle *port, > + struct drm_dp_typec_switch_desc *switch_desc, > + void *data, typec_mux_set_fn_t mux_set); > +#else > +static inline void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc) > +{ > +} > +static inline int drm_dp_register_typec_switches( > + struct device *dev, struct fwnode_handle *port, > + struct drm_dp_typec_switch_desc *switch_desc, void *data, > + typec_mux_set_fn_t mux_set) > +{ > + return -EOPNOTSUPP; > +} > +#endif > + > #endif /* _DRM_DP_HELPER_H_ */ > -- > 2.40.0.rc1.284.g88254d51c5-goog >
On Wed, Mar 22, 2023 at 06:27:56PM +0200, Jani Nikula wrote: > On Wed, 22 Mar 2023, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > > On Wed, Mar 22, 2023 at 06:46:32PM +0800, Pin-yen Lin wrote: > >> +#ifdef CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER > > > > Ah, maybe this should use IS_REACHABLE() ? > > Personally, I think IS_REACHABLE() is a build-time band-aid solution to > a problem that should be solved in Kconfig. :p > > I think it always means there's a configuration combo that shouldn't > exist, and it's a surprise to the user when they've configured > something, Kconfig has deemed it a valid configuration, but they don't > get the feature they want. > > As a user, how would they even debug that case? Double check configs, > don't see anything wrong. Usual pairing is 'imply FOO' in Kconfig & 'IS_REACHEABLE(CONFIG_FOO)' in the code. And I believe it's not an abnormal.
On Thu, Mar 23, 2023 at 12:38:49AM +0200, Dmitry Baryshkov wrote: > On Wed, 22 Mar 2023 at 12:47, Pin-yen Lin <treapking@chromium.org> wrote: ... > > +config DRM_DISPLAY_DP_TYPEC_HELPER > > + bool > > + default y > > + depends on DRM_DISPLAY_HELPER > > + depends on DRM_DISPLAY_HELPER=TYPEC || TYPEC=y > > If it is a select'able option, it doesn't make sense to use "depends" > here. Select will override depends. He-he, not so easy. This will help to find configurations that miss these dependencies. Arnd taught me that. IIRC the ASoC subsystem has a lot of such cases. > > + help > > + DRM display helpers for USB Type-C Displayport Alternate mode.
Hi Andy, Thanks for the review. On Wed, Mar 22, 2023 at 8:01 PM Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > > On Wed, Mar 22, 2023 at 06:46:32PM +0800, Pin-yen Lin wrote: > > Add helpers to register and unregister Type-C "switches" for bridges > > capable of switching their output between two downstream devices. > > > > The helper registers USB Type-C mode switches when the "mode-switch" > > and the "reg" properties are available in Device Tree. > > ... > > > +config DRM_DISPLAY_DP_TYPEC_HELPER > > > + bool > > + default y > > def_bool y > > > + depends on DRM_DISPLAY_HELPER > > + depends on DRM_DISPLAY_HELPER=TYPEC || TYPEC=y > > + help > > + DRM display helpers for USB Type-C Displayport Alternate mode. > > Hmm... Dunno if this help is enough. Okay I'll add more detail in the next version. > > ... > > > + snprintf(name, sizeof(name), "%pfwP-%u", fwnode, port_num); > > Would it be possible to have a dup in name and would it be a problem if so? > The port_num is included in the name, so the names should be unique. Also, the fwnode name actually contains the reg property, so this name looks like "endpoint@0-1" now... I'll change the name from fwnode name to dev_name() per Dmitry's comment. > ... > > > +/** > > + * drm_dp_register_typec_switches() - register Type-C switches > > + * @dev: Device that registers Type-C switches > > + * @port: Device node for the switch > > + * @switch_desc: A Type-C switch descriptor > > + * @data: Private data for the switches > > + * @mux_set: Callback function for typec_mux_set > > + * > > + * This function registers USB Type-C switches for DP bridges that can switch > > + * the output signal between their output pins. This function uses devm_kcalloc > > + * to allocate memory, so it is expected to only call this in the driver probe > > + * functions. > > + * > > + * Currently only mode switches are implemented, and the function assumes the > > + * given @port device node has endpoints with "mode-switch" property. > > + * The port number is determined by the "reg" property of the endpoint. > > `kernel-doc -v ...` should complain on absence of "Return" section. > > > + */ > > ... > > > + switch_desc->typec_ports = devm_kcalloc(dev, switch_desc->num_typec_switches, > > + sizeof(struct drm_dp_typec_port_data), > > sizeof(*switch_desc_typec_ports), > > ? > > > + GFP_KERNEL); > > + if (!switch_desc->typec_ports) > > + return -ENOMEM; > > ... > > > +#ifdef CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER > > Ah, maybe this should use IS_REACHABLE() ? CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER is a boolean. Is there any difference between IS_REACHABLE and ifdef when the given config is a boolean? > > > +void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc); > > +int drm_dp_register_typec_switches(struct device *dev, struct fwnode_handle *port, > > + struct drm_dp_typec_switch_desc *switch_desc, > > + void *data, typec_mux_set_fn_t mux_set); > > +#else > > +static inline void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc) > > +{ > > +} > > +static inline int drm_dp_register_typec_switches( > > + struct device *dev, struct fwnode_handle *port, > > + struct drm_dp_typec_switch_desc *switch_desc, void *data, > > + typec_mux_set_fn_t mux_set) > > +{ > > + return -EOPNOTSUPP; > > +} > > +#endif > > -- > With Best Regards, > Andy Shevchenko > Best regards, Pin-yen >
Hi Dmitry, Thanks for the review. On Thu, Mar 23, 2023 at 7:39 AM Dmitry Baryshkov <dmitry.baryshkov@linaro.org> wrote: > > On Wed, 22 Mar 2023 at 12:47, Pin-yen Lin <treapking@chromium.org> wrote: > > > > Add helpers to register and unregister Type-C "switches" for bridges > > capable of switching their output between two downstream devices. > > > > The helper registers USB Type-C mode switches when the "mode-switch" > > and the "reg" properties are available in Device Tree. > > > > Signed-off-by: Pin-yen Lin <treapking@chromium.org> > > > > --- > > > > Changes in v14: > > - Introduce a new Kconfig becuase it didn't build when CONFIG_TYPEC=m > > - Add comments about devm_* usage > > - Fix style issues > > > > Changes in v13: > > - Add typec_mode_switch_node_count helper > > - Fix style issues > > > > Changes in v12: > > - Add fwnode_for_each_typec_mode_switch macro > > - Remove a duplicated dmesg in the helper > > - Used IS_REACHABLE instead to guard the function signatures > > > > Changes in v11: > > - Use fwnode helpers instead of DT > > - Moved the helpers to a new file > > - Use "reg" instead of "data-lanes" to determine the port number > > - Dropped collected tags due to new changes > > > > Changes in v10: > > - Collected Reviewed-by and Tested-by tags > > - Replaced "void *" with "typec_mux_set_fn_t" for mux_set callbacks > > - Print out the node name when errors on parsing DT > > - Use dev_dbg instead of dev_warn when no Type-C switch nodes available > > - Made the return path of drm_dp_register_mode_switch clearer > > > > Changes in v8: > > - Fixed the build issue when CONFIG_TYPEC=m > > - Fixed some style issues > > > > Changes in v7: > > - Extracted the common codes to a helper function > > - New in v7 > > > > drivers/gpu/drm/display/Kconfig | 8 ++ > > drivers/gpu/drm/display/Makefile | 2 + > > drivers/gpu/drm/display/drm_dp_typec_helper.c | 105 ++++++++++++++++++ > > include/drm/display/drm_dp_helper.h | 46 ++++++++ > > 4 files changed, 161 insertions(+) > > create mode 100644 drivers/gpu/drm/display/drm_dp_typec_helper.c > > > > diff --git a/drivers/gpu/drm/display/Kconfig b/drivers/gpu/drm/display/Kconfig > > index 09712b88a5b8..d61076947a1c 100644 > > --- a/drivers/gpu/drm/display/Kconfig > > +++ b/drivers/gpu/drm/display/Kconfig > > @@ -29,6 +29,14 @@ config DRM_DISPLAY_HDMI_HELPER > > help > > DRM display helpers for HDMI. > > > > +config DRM_DISPLAY_DP_TYPEC_HELPER > > + bool > > + default y > > + depends on DRM_DISPLAY_HELPER > > + depends on DRM_DISPLAY_HELPER=TYPEC || TYPEC=y > > If it is a select'able option, it doesn't make sense to use "depends" > here. Select will override depends. > I'm not very familiar with the practices of Kconfigs, but I'll keep this in the next version per Andy's comment. > > + help > > + DRM display helpers for USB Type-C Displayport Alternate mode. > > + > > config DRM_DP_AUX_CHARDEV > > bool "DRM DP AUX Interface" > > depends on DRM && DRM_DISPLAY_HELPER > > diff --git a/drivers/gpu/drm/display/Makefile b/drivers/gpu/drm/display/Makefile > > index 17ac4a1006a8..2202a6aea38e 100644 > > --- a/drivers/gpu/drm/display/Makefile > > +++ b/drivers/gpu/drm/display/Makefile > > @@ -8,6 +8,8 @@ drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_HELPER) += \ > > drm_dp_helper.o \ > > drm_dp_mst_topology.o \ > > drm_dsc_helper.o > > +drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER) += \ > > + drm_dp_typec_helper.o > > drm_display_helper-$(CONFIG_DRM_DISPLAY_HDCP_HELPER) += drm_hdcp_helper.o > > drm_display_helper-$(CONFIG_DRM_DISPLAY_HDMI_HELPER) += \ > > drm_hdmi_helper.o \ > > diff --git a/drivers/gpu/drm/display/drm_dp_typec_helper.c b/drivers/gpu/drm/display/drm_dp_typec_helper.c > > new file mode 100644 > > index 000000000000..1562a9ccdaf2 > > --- /dev/null > > +++ b/drivers/gpu/drm/display/drm_dp_typec_helper.c > > @@ -0,0 +1,105 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > + > > +#include <linux/usb/typec_mux.h> > > +#include <drm/display/drm_dp_helper.h> > > + > > +static int drm_dp_register_mode_switch(struct device *dev, > > + struct fwnode_handle *fwnode, > > + struct drm_dp_typec_switch_desc *switch_desc, > > + void *data, typec_mux_set_fn_t mux_set) > > +{ > > + struct drm_dp_typec_port_data *port_data; > > + struct typec_mux_desc mux_desc = {}; > > + char name[32]; > > Why 32? This is just a random length that is probably sufficiently large. I see other users use the pointer from `fwnode_get_name` directly, but we want to append the port number to ensure the names are unique. > > > + u32 port_num; > > + int ret; > > + > > + ret = fwnode_property_read_u32(fwnode, "reg", &port_num); > > + if (ret) { > > + dev_err(dev, "Failed to read reg property: %d\n", ret); > > + return ret; > > + } > > + > > + port_data = &switch_desc->typec_ports[port_num]; > > + port_data->data = data; > > + port_data->port_num = port_num; > > + port_data->fwnode = fwnode; > > + mux_desc.fwnode = fwnode; > > + mux_desc.drvdata = port_data; > > + snprintf(name, sizeof(name), "%pfwP-%u", fwnode, port_num); > > I think it makes more sense to use dev_name here instead of fwnode. Thanks for the suggestions. I'll update this in the next version. > > > + mux_desc.name = name; > > + mux_desc.set = mux_set; > > + > > + port_data->typec_mux = typec_mux_register(dev, &mux_desc); > > + ret = PTR_ERR_OR_ZERO(port_data->typec_mux); > > + if (ret) > > + dev_err(dev, "Mode switch register for port %d failed: %d\n", > > + port_num, ret); > > + > > + return ret; > > +} > > + > > +/** > > + * drm_dp_register_typec_switches() - register Type-C switches > > + * @dev: Device that registers Type-C switches > > + * @port: Device node for the switch > > + * @switch_desc: A Type-C switch descriptor > > + * @data: Private data for the switches > > + * @mux_set: Callback function for typec_mux_set > > + * > > + * This function registers USB Type-C switches for DP bridges that can switch > > + * the output signal between their output pins. This function uses devm_kcalloc > > + * to allocate memory, so it is expected to only call this in the driver probe > > + * functions. > > + * > > + * Currently only mode switches are implemented, and the function assumes the > > + * given @port device node has endpoints with "mode-switch" property. > > + * The port number is determined by the "reg" property of the endpoint. > > + */ > > +int drm_dp_register_typec_switches(struct device *dev, struct fwnode_handle *port, > > + struct drm_dp_typec_switch_desc *switch_desc, > > + void *data, typec_mux_set_fn_t mux_set) > > +{ > > + struct fwnode_handle *sw; > > + int ret; > > + > > + switch_desc->num_typec_switches = typec_mode_switch_node_count(port); > > + if (!switch_desc->num_typec_switches) { > > + dev_dbg(dev, "No Type-C switches node found\n"); > > + return 0; > > + } > > + > > + switch_desc->typec_ports = devm_kcalloc(dev, switch_desc->num_typec_switches, > > + sizeof(struct drm_dp_typec_port_data), > > + GFP_KERNEL); > > + if (!switch_desc->typec_ports) > > + return -ENOMEM; > > + > > + /* Register switches for each connector. */ > > + for_each_typec_mode_switch_node(port, sw) { > > + ret = drm_dp_register_mode_switch(dev, sw, switch_desc, data, mux_set); > > + if (ret) > > + goto err_unregister_typec_switches; > > + } > > + > > + return 0; > > + > > +err_unregister_typec_switches: > > + fwnode_handle_put(sw); > > + drm_dp_unregister_typec_switches(switch_desc); > > + return ret; > > +} > > +EXPORT_SYMBOL(drm_dp_register_typec_switches); > > + > > +/** > > + * drm_dp_unregister_typec_switches() - unregister Type-C switches > > + * @switch_desc: A Type-C switch descriptor > > + */ > > +void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc) > > +{ > > + unsigned int i; > > + > > + for (i = 0; i < switch_desc->num_typec_switches; i++) > > + typec_mux_unregister(switch_desc->typec_ports[i].typec_mux); > > +} > > +EXPORT_SYMBOL(drm_dp_unregister_typec_switches); > > diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h > > index ab55453f2d2c..0fe56586d7bc 100644 > > --- a/include/drm/display/drm_dp_helper.h > > +++ b/include/drm/display/drm_dp_helper.h > > @@ -25,6 +25,7 @@ > > > > #include <linux/delay.h> > > #include <linux/i2c.h> > > +#include <linux/usb/typec_mux.h> > > > > #include <drm/display/drm_dp.h> > > #include <drm/drm_connector.h> > > @@ -763,4 +764,49 @@ bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZ > > const u8 port_cap[4], u8 color_spc); > > int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc); > > > > +struct drm_dp_typec_port_data { > > + struct typec_mux_dev *typec_mux; > > + int port_num; > > + struct fwnode_handle *fwnode; > > + void *data; > > +}; > > + > > +struct drm_dp_typec_switch_desc { > > + int num_typec_switches; > > + struct drm_dp_typec_port_data *typec_ports; > > +}; > > + > > +#define for_each_typec_mode_switch_node(port, sw) \ > > + fwnode_for_each_child_node((port), (sw)) \ > > + for_each_if(fwnode_property_present((sw), "mode-switch")) > > + > > +static inline unsigned int typec_mode_switch_node_count(struct fwnode_handle *port) > > +{ > > + struct fwnode_handle *sw; > > + unsigned int count = 0; > > + > > + for_each_typec_mode_switch_node(port, sw) > > + count++; > > + > > + return count; > > +} > > + > > +#ifdef CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER > > +void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc); > > +int drm_dp_register_typec_switches(struct device *dev, struct fwnode_handle *port, > > + struct drm_dp_typec_switch_desc *switch_desc, > > + void *data, typec_mux_set_fn_t mux_set); > > +#else > > +static inline void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc) > > +{ > > +} > > +static inline int drm_dp_register_typec_switches( > > + struct device *dev, struct fwnode_handle *port, > > + struct drm_dp_typec_switch_desc *switch_desc, void *data, > > + typec_mux_set_fn_t mux_set) > > +{ > > + return -EOPNOTSUPP; > > +} > > +#endif > > + > > #endif /* _DRM_DP_HELPER_H_ */ > > -- > > 2.40.0.rc1.284.g88254d51c5-goog > > > > > -- > With best wishes > Dmitry Best regards, Pin-yen
On Fri, Mar 31, 2023 at 11:36 AM Pin-yen Lin <treapking@chromium.org> wrote: > > Hi Andy, > > Thanks for the review. > > On Wed, Mar 22, 2023 at 8:01 PM Andy Shevchenko > <andriy.shevchenko@linux.intel.com> wrote: > > > > On Wed, Mar 22, 2023 at 06:46:32PM +0800, Pin-yen Lin wrote: > > > Add helpers to register and unregister Type-C "switches" for bridges > > > capable of switching their output between two downstream devices. > > > > > > The helper registers USB Type-C mode switches when the "mode-switch" > > > and the "reg" properties are available in Device Tree. > > > > ... > > > > > +config DRM_DISPLAY_DP_TYPEC_HELPER > > > > > + bool > > > + default y > > > > def_bool y > > > > > + depends on DRM_DISPLAY_HELPER > > > + depends on DRM_DISPLAY_HELPER=TYPEC || TYPEC=y > > > + help > > > + DRM display helpers for USB Type-C Displayport Alternate mode. > > > > Hmm... Dunno if this help is enough. > > Okay I'll add more detail in the next version. > > > > ... > > > > > + snprintf(name, sizeof(name), "%pfwP-%u", fwnode, port_num); > > > > Would it be possible to have a dup in name and would it be a problem if so? > > > The port_num is included in the name, so the names should be unique. > Also, the fwnode name actually contains the reg property, so this name > looks like "endpoint@0-1" now... I'll change the name from fwnode name This should be "endpoint@0-0", or "endpoint@1-1@. The `port_num` value has the same number as the `reg` property > to dev_name() per Dmitry's comment. > > ... > > > > > +/** > > > + * drm_dp_register_typec_switches() - register Type-C switches > > > + * @dev: Device that registers Type-C switches > > > + * @port: Device node for the switch > > > + * @switch_desc: A Type-C switch descriptor > > > + * @data: Private data for the switches > > > + * @mux_set: Callback function for typec_mux_set > > > + * > > > + * This function registers USB Type-C switches for DP bridges that can switch > > > + * the output signal between their output pins. This function uses devm_kcalloc > > > + * to allocate memory, so it is expected to only call this in the driver probe > > > + * functions. > > > + * > > > + * Currently only mode switches are implemented, and the function assumes the > > > + * given @port device node has endpoints with "mode-switch" property. > > > + * The port number is determined by the "reg" property of the endpoint. > > > > `kernel-doc -v ...` should complain on absence of "Return" section. > > > > > + */ > > > > ... > > > > > + switch_desc->typec_ports = devm_kcalloc(dev, switch_desc->num_typec_switches, > > > + sizeof(struct drm_dp_typec_port_data), > > > > sizeof(*switch_desc_typec_ports), > > > > ? > > > > > + GFP_KERNEL); > > > + if (!switch_desc->typec_ports) > > > + return -ENOMEM; > > > > ... > > > > > +#ifdef CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER > > > > Ah, maybe this should use IS_REACHABLE() ? > > CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER is a boolean. Is there any > difference between IS_REACHABLE and ifdef when the given config is a > boolean? > > > > > +void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc); > > > +int drm_dp_register_typec_switches(struct device *dev, struct fwnode_handle *port, > > > + struct drm_dp_typec_switch_desc *switch_desc, > > > + void *data, typec_mux_set_fn_t mux_set); > > > +#else > > > +static inline void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc) > > > +{ > > > +} > > > +static inline int drm_dp_register_typec_switches( > > > + struct device *dev, struct fwnode_handle *port, > > > + struct drm_dp_typec_switch_desc *switch_desc, void *data, > > > + typec_mux_set_fn_t mux_set) > > > +{ > > > + return -EOPNOTSUPP; > > > +} > > > +#endif > > > > -- > > With Best Regards, > > Andy Shevchenko > > > > Best regards, > Pin-yen > >
diff --git a/drivers/gpu/drm/display/Kconfig b/drivers/gpu/drm/display/Kconfig index 09712b88a5b8..d61076947a1c 100644 --- a/drivers/gpu/drm/display/Kconfig +++ b/drivers/gpu/drm/display/Kconfig @@ -29,6 +29,14 @@ config DRM_DISPLAY_HDMI_HELPER help DRM display helpers for HDMI. +config DRM_DISPLAY_DP_TYPEC_HELPER + bool + default y + depends on DRM_DISPLAY_HELPER + depends on DRM_DISPLAY_HELPER=TYPEC || TYPEC=y + help + DRM display helpers for USB Type-C Displayport Alternate mode. + config DRM_DP_AUX_CHARDEV bool "DRM DP AUX Interface" depends on DRM && DRM_DISPLAY_HELPER diff --git a/drivers/gpu/drm/display/Makefile b/drivers/gpu/drm/display/Makefile index 17ac4a1006a8..2202a6aea38e 100644 --- a/drivers/gpu/drm/display/Makefile +++ b/drivers/gpu/drm/display/Makefile @@ -8,6 +8,8 @@ drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_HELPER) += \ drm_dp_helper.o \ drm_dp_mst_topology.o \ drm_dsc_helper.o +drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER) += \ + drm_dp_typec_helper.o drm_display_helper-$(CONFIG_DRM_DISPLAY_HDCP_HELPER) += drm_hdcp_helper.o drm_display_helper-$(CONFIG_DRM_DISPLAY_HDMI_HELPER) += \ drm_hdmi_helper.o \ diff --git a/drivers/gpu/drm/display/drm_dp_typec_helper.c b/drivers/gpu/drm/display/drm_dp_typec_helper.c new file mode 100644 index 000000000000..1562a9ccdaf2 --- /dev/null +++ b/drivers/gpu/drm/display/drm_dp_typec_helper.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/usb/typec_mux.h> +#include <drm/display/drm_dp_helper.h> + +static int drm_dp_register_mode_switch(struct device *dev, + struct fwnode_handle *fwnode, + struct drm_dp_typec_switch_desc *switch_desc, + void *data, typec_mux_set_fn_t mux_set) +{ + struct drm_dp_typec_port_data *port_data; + struct typec_mux_desc mux_desc = {}; + char name[32]; + u32 port_num; + int ret; + + ret = fwnode_property_read_u32(fwnode, "reg", &port_num); + if (ret) { + dev_err(dev, "Failed to read reg property: %d\n", ret); + return ret; + } + + port_data = &switch_desc->typec_ports[port_num]; + port_data->data = data; + port_data->port_num = port_num; + port_data->fwnode = fwnode; + mux_desc.fwnode = fwnode; + mux_desc.drvdata = port_data; + snprintf(name, sizeof(name), "%pfwP-%u", fwnode, port_num); + mux_desc.name = name; + mux_desc.set = mux_set; + + port_data->typec_mux = typec_mux_register(dev, &mux_desc); + ret = PTR_ERR_OR_ZERO(port_data->typec_mux); + if (ret) + dev_err(dev, "Mode switch register for port %d failed: %d\n", + port_num, ret); + + return ret; +} + +/** + * drm_dp_register_typec_switches() - register Type-C switches + * @dev: Device that registers Type-C switches + * @port: Device node for the switch + * @switch_desc: A Type-C switch descriptor + * @data: Private data for the switches + * @mux_set: Callback function for typec_mux_set + * + * This function registers USB Type-C switches for DP bridges that can switch + * the output signal between their output pins. This function uses devm_kcalloc + * to allocate memory, so it is expected to only call this in the driver probe + * functions. + * + * Currently only mode switches are implemented, and the function assumes the + * given @port device node has endpoints with "mode-switch" property. + * The port number is determined by the "reg" property of the endpoint. + */ +int drm_dp_register_typec_switches(struct device *dev, struct fwnode_handle *port, + struct drm_dp_typec_switch_desc *switch_desc, + void *data, typec_mux_set_fn_t mux_set) +{ + struct fwnode_handle *sw; + int ret; + + switch_desc->num_typec_switches = typec_mode_switch_node_count(port); + if (!switch_desc->num_typec_switches) { + dev_dbg(dev, "No Type-C switches node found\n"); + return 0; + } + + switch_desc->typec_ports = devm_kcalloc(dev, switch_desc->num_typec_switches, + sizeof(struct drm_dp_typec_port_data), + GFP_KERNEL); + if (!switch_desc->typec_ports) + return -ENOMEM; + + /* Register switches for each connector. */ + for_each_typec_mode_switch_node(port, sw) { + ret = drm_dp_register_mode_switch(dev, sw, switch_desc, data, mux_set); + if (ret) + goto err_unregister_typec_switches; + } + + return 0; + +err_unregister_typec_switches: + fwnode_handle_put(sw); + drm_dp_unregister_typec_switches(switch_desc); + return ret; +} +EXPORT_SYMBOL(drm_dp_register_typec_switches); + +/** + * drm_dp_unregister_typec_switches() - unregister Type-C switches + * @switch_desc: A Type-C switch descriptor + */ +void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc) +{ + unsigned int i; + + for (i = 0; i < switch_desc->num_typec_switches; i++) + typec_mux_unregister(switch_desc->typec_ports[i].typec_mux); +} +EXPORT_SYMBOL(drm_dp_unregister_typec_switches); diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h index ab55453f2d2c..0fe56586d7bc 100644 --- a/include/drm/display/drm_dp_helper.h +++ b/include/drm/display/drm_dp_helper.h @@ -25,6 +25,7 @@ #include <linux/delay.h> #include <linux/i2c.h> +#include <linux/usb/typec_mux.h> #include <drm/display/drm_dp.h> #include <drm/drm_connector.h> @@ -763,4 +764,49 @@ bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZ const u8 port_cap[4], u8 color_spc); int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc); +struct drm_dp_typec_port_data { + struct typec_mux_dev *typec_mux; + int port_num; + struct fwnode_handle *fwnode; + void *data; +}; + +struct drm_dp_typec_switch_desc { + int num_typec_switches; + struct drm_dp_typec_port_data *typec_ports; +}; + +#define for_each_typec_mode_switch_node(port, sw) \ + fwnode_for_each_child_node((port), (sw)) \ + for_each_if(fwnode_property_present((sw), "mode-switch")) + +static inline unsigned int typec_mode_switch_node_count(struct fwnode_handle *port) +{ + struct fwnode_handle *sw; + unsigned int count = 0; + + for_each_typec_mode_switch_node(port, sw) + count++; + + return count; +} + +#ifdef CONFIG_DRM_DISPLAY_DP_TYPEC_HELPER +void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc); +int drm_dp_register_typec_switches(struct device *dev, struct fwnode_handle *port, + struct drm_dp_typec_switch_desc *switch_desc, + void *data, typec_mux_set_fn_t mux_set); +#else +static inline void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc) +{ +} +static inline int drm_dp_register_typec_switches( + struct device *dev, struct fwnode_handle *port, + struct drm_dp_typec_switch_desc *switch_desc, void *data, + typec_mux_set_fn_t mux_set) +{ + return -EOPNOTSUPP; +} +#endif + #endif /* _DRM_DP_HELPER_H_ */
Add helpers to register and unregister Type-C "switches" for bridges capable of switching their output between two downstream devices. The helper registers USB Type-C mode switches when the "mode-switch" and the "reg" properties are available in Device Tree. Signed-off-by: Pin-yen Lin <treapking@chromium.org> --- Changes in v14: - Introduce a new Kconfig becuase it didn't build when CONFIG_TYPEC=m - Add comments about devm_* usage - Fix style issues Changes in v13: - Add typec_mode_switch_node_count helper - Fix style issues Changes in v12: - Add fwnode_for_each_typec_mode_switch macro - Remove a duplicated dmesg in the helper - Used IS_REACHABLE instead to guard the function signatures Changes in v11: - Use fwnode helpers instead of DT - Moved the helpers to a new file - Use "reg" instead of "data-lanes" to determine the port number - Dropped collected tags due to new changes Changes in v10: - Collected Reviewed-by and Tested-by tags - Replaced "void *" with "typec_mux_set_fn_t" for mux_set callbacks - Print out the node name when errors on parsing DT - Use dev_dbg instead of dev_warn when no Type-C switch nodes available - Made the return path of drm_dp_register_mode_switch clearer Changes in v8: - Fixed the build issue when CONFIG_TYPEC=m - Fixed some style issues Changes in v7: - Extracted the common codes to a helper function - New in v7 drivers/gpu/drm/display/Kconfig | 8 ++ drivers/gpu/drm/display/Makefile | 2 + drivers/gpu/drm/display/drm_dp_typec_helper.c | 105 ++++++++++++++++++ include/drm/display/drm_dp_helper.h | 46 ++++++++ 4 files changed, 161 insertions(+) create mode 100644 drivers/gpu/drm/display/drm_dp_typec_helper.c