diff options
Diffstat (limited to 'drivers/gpu/drm/drm_panel.c')
| -rw-r--r-- | drivers/gpu/drm/drm_panel.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index 308d442a531b..b902361dee6e 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -24,6 +24,7 @@ #include <linux/err.h> #include <linux/module.h> +#include <drm/drm_device.h> #include <drm/drm_crtc.h> #include <drm/drm_panel.h> @@ -94,6 +95,9 @@ EXPORT_SYMBOL(drm_panel_remove); * * An error is returned if the panel is already attached to another connector. * + * When unloading, the driver should detach from the panel by calling + * drm_panel_detach(). + * * Return: 0 on success or a negative error code on failure. */ int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector) @@ -101,6 +105,13 @@ int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector) if (panel->connector) return -EBUSY; + panel->link = device_link_add(connector->dev->dev, panel->dev, 0); + if (!panel->link) { + dev_err(panel->dev, "failed to link panel to %s\n", + dev_name(connector->dev->dev)); + return -EINVAL; + } + panel->connector = connector; panel->drm = connector->dev; @@ -115,10 +126,15 @@ EXPORT_SYMBOL(drm_panel_attach); * Detaches a panel from the connector it is attached to. If a panel is not * attached to any connector this is effectively a no-op. * + * This function should not be called by the panel device itself. It + * is only for the drm device that called drm_panel_attach(). + * * Return: 0 on success or a negative error code on failure. */ int drm_panel_detach(struct drm_panel *panel) { + device_link_del(panel->link); + panel->connector = NULL; panel->drm = NULL; @@ -135,12 +151,19 @@ EXPORT_SYMBOL(drm_panel_detach); * tree node. If a matching panel is found, return a pointer to it. * * Return: A pointer to the panel registered for the specified device tree - * node or NULL if no panel matching the device tree node can be found. + * node or an ERR_PTR() if no panel matching the device tree node can be found. + * Possible error codes returned by this function: + * - EPROBE_DEFER: the panel device has not been probed yet, and the caller + * should retry later + * - ENODEV: the device is not available (status != "okay" or "ok") */ struct drm_panel *of_drm_find_panel(const struct device_node *np) { struct drm_panel *panel; + if (!of_device_is_available(np)) + return ERR_PTR(-ENODEV); + mutex_lock(&panel_lock); list_for_each_entry(panel, &panel_list, list) { @@ -151,7 +174,7 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np) } mutex_unlock(&panel_lock); - return NULL; + return ERR_PTR(-EPROBE_DEFER); } EXPORT_SYMBOL(of_drm_find_panel); #endif |