>-----Original Message----- >From: Intel-gfx [mailto:[email protected]] On Behalf Of >Jani Nikula >Sent: Wednesday, April 1, 2015 1:45 PM >To: [email protected] >Cc: Nikula, Jani >Subject: [Intel-gfx] [PATCH v2] drm/i915: add i915 specific connector debugfs >file for DPCD > >Occasionally it would be interesting to read some of the DPCD registers >for debug purposes, without having to resort to logging. Add an i915 >specific i915_dpcd debugfs file for DP and eDP connectors to dump parts >of the DPCD. Currently the DPCD addresses to be dumped are statically >configured, and more can be added trivially. > >The implementation also makes it relatively easy to add other i915 and >connector specific debugfs files in the future, as necessary. > >This is currently i915 specific just because there's no generic way to >do AUX transactions given just a drm_connector. However it's all pretty >straightforward to port to other drivers. > >v2: Add more DPCD registers to dump. >
Tested-by: Durgadoss R <[email protected]> Thanks, Durga >Signed-off-by: Jani Nikula <[email protected]> >--- > drivers/gpu/drm/i915/i915_debugfs.c | 96 +++++++++++++++++++++++++++++++++++++ > drivers/gpu/drm/i915/i915_drv.h | 1 + > drivers/gpu/drm/i915/intel_dp.c | 2 + > 3 files changed, 99 insertions(+) > >diff --git a/drivers/gpu/drm/i915/i915_debugfs.c >b/drivers/gpu/drm/i915/i915_debugfs.c >index 007c7d7d8295..7164aa7d5fd3 100644 >--- a/drivers/gpu/drm/i915/i915_debugfs.c >+++ b/drivers/gpu/drm/i915/i915_debugfs.c >@@ -4780,3 +4780,99 @@ void i915_debugfs_cleanup(struct drm_minor *minor) > drm_debugfs_remove_files(info_list, 1, minor); > } > } >+ >+struct dpcd_block { >+ /* DPCD dump start address. */ >+ unsigned int offset; >+ /* DPCD dump end address, inclusive. If unset, .size will be used. */ >+ unsigned int end; >+ /* DPCD dump size. Used if .end is unset. If unset, defaults to 1. */ >+ size_t size; >+ /* Only valid for eDP. */ >+ bool edp; >+}; >+ >+static const struct dpcd_block i915_dpcd_debug[] = { >+ { .offset = DP_DPCD_REV, .size = DP_RECEIVER_CAP_SIZE }, >+ { .offset = DP_PSR_SUPPORT, .end = DP_PSR_CAPS }, >+ { .offset = DP_DOWNSTREAM_PORT_0, .size = 16 }, >+ { .offset = DP_LINK_BW_SET, .end = DP_EDP_CONFIGURATION_SET }, >+ { .offset = DP_SINK_COUNT, .end = DP_ADJUST_REQUEST_LANE2_3 }, >+ { .offset = DP_SET_POWER }, >+ { .offset = DP_EDP_DPCD_REV }, >+ { .offset = DP_EDP_GENERAL_CAP_1, .end = DP_EDP_GENERAL_CAP_3 }, >+ { .offset = DP_EDP_DISPLAY_CONTROL_REGISTER, .end = >DP_EDP_BACKLIGHT_FREQ_CAP_MAX_LSB }, >+ { .offset = DP_EDP_DBC_MINIMUM_BRIGHTNESS_SET, .end = >DP_EDP_DBC_MAXIMUM_BRIGHTNESS_SET }, >+}; >+ >+static int i915_dpcd_show(struct seq_file *m, void *data) >+{ >+ struct drm_connector *connector = m->private; >+ struct intel_dp *intel_dp = >+ enc_to_intel_dp(&intel_attached_encoder(connector)->base); >+ uint8_t buf[16]; >+ ssize_t err; >+ int i; >+ >+ for (i = 0; i < ARRAY_SIZE(i915_dpcd_debug); i++) { >+ const struct dpcd_block *b = &i915_dpcd_debug[i]; >+ size_t size = b->end ? b->end - b->offset + 1 : (b->size ?: 1); >+ >+ if (b->edp && >+ connector->connector_type != DRM_MODE_CONNECTOR_eDP) >+ continue; >+ >+ /* low tech for now */ >+ if (WARN_ON(size > sizeof(buf))) >+ continue; >+ >+ err = drm_dp_dpcd_read(&intel_dp->aux, b->offset, buf, size); >+ if (err <= 0) { >+ DRM_ERROR("dpcd read (%zu bytes at %u) failed (%zd)\n", >+ size, b->offset, err); >+ continue; >+ } >+ >+ seq_printf(m, "%04x: %*ph\n", b->offset, (int) size, buf); >+ }; >+ >+ return 0; >+} >+ >+static int i915_dpcd_open(struct inode *inode, struct file *file) >+{ >+ return single_open(file, i915_dpcd_show, inode->i_private); >+} >+ >+static const struct file_operations i915_dpcd_fops = { >+ .owner = THIS_MODULE, >+ .open = i915_dpcd_open, >+ .read = seq_read, >+ .llseek = seq_lseek, >+ .release = single_release, >+}; >+ >+/** >+ * i915_debugfs_connector_add - add i915 specific connector debugfs files >+ * @connector: pointer to a registered drm_connector >+ * >+ * Cleanup will be done by drm_connector_unregister() through a call to >+ * drm_debugfs_connector_remove(). >+ * >+ * Returns 0 on success, negative error codes on error. >+ */ >+int i915_debugfs_connector_add(struct drm_connector *connector) >+{ >+ struct dentry *root = connector->debugfs_entry; >+ >+ /* The connector must have been registered beforehands. */ >+ if (!root) >+ return -ENODEV; >+ >+ if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort || >+ connector->connector_type == DRM_MODE_CONNECTOR_eDP) >+ debugfs_create_file("i915_dpcd", S_IRUGO, root, connector, >+ &i915_dpcd_fops); >+ >+ return 0; >+} >diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h >index aadada5a3fe9..868f26780115 100644 >--- a/drivers/gpu/drm/i915/i915_drv.h >+++ b/drivers/gpu/drm/i915/i915_drv.h >@@ -3011,6 +3011,7 @@ int i915_verify_lists(struct drm_device *dev); > /* i915_debugfs.c */ > int i915_debugfs_init(struct drm_minor *minor); > void i915_debugfs_cleanup(struct drm_minor *minor); >+int i915_debugfs_connector_add(struct drm_connector *connector); > #ifdef CONFIG_DEBUG_FS > void intel_display_crc_init(struct drm_device *dev); > #else >diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c >index 7936155acbe8..f91ce9e94aa6 100644 >--- a/drivers/gpu/drm/i915/intel_dp.c >+++ b/drivers/gpu/drm/i915/intel_dp.c >@@ -5569,6 +5569,8 @@ intel_dp_init_connector(struct intel_digital_port >*intel_dig_port, > I915_WRITE(PEG_BAND_GAP_DATA, (temp & ~0xf) | 0xd); > } > >+ i915_debugfs_connector_add(connector); >+ > return true; > } > >-- >2.1.4 > >_______________________________________________ >Intel-gfx mailing list >[email protected] >http://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
