diff options
| author | Dave Airlie <airlied@redhat.com> | 2019-10-30 06:10:59 +1000 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2019-10-30 06:11:47 +1000 |
| commit | a24e4b09dc75357492ca19d74b02e1edebc282e8 (patch) | |
| tree | d94d65004f9b9a2a5b6e1bc4a5d1f9c322645996 /drivers/gpu/drm/tegra/dp.c | |
| parent | 60845e34f0c5c19a9e86af477b429993952f585b (diff) | |
| parent | 9a42c7c647a9ad0f7ebb147a52eda3dcb7c84292 (diff) | |
Merge tag 'drm-misc-next-2019-10-24-2' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
drm-misc-next for 5.5:
UAPI Changes:
-syncobj: allow querying the last submitted timeline value (David)
-fourcc: explicitly defineDRM_FORMAT_BIG_ENDIAN as unsigned (Adam)
-omap: revert the OMAP_BO_* flags that were added -- no userspace (Sean)
Cross-subsystem Changes:
-MAINTAINERS: add Mihail as komeda co-maintainer (Mihail)
Core Changes:
-edid: a few cleanups, add AVI infoframe bar info (Ville)
-todo: remove i915 device_link item and add difficulty levels (Daniel)
-dp_helpers: add a few new helpers to parse dpcd (Thierry)
Driver Changes:
-gma500: fix a few memory disclosure leaks (Kangjie)
-qxl: convert to use the new drm_gem_object_funcs.mmap (Gerd)
-various: open code dp_link helpers in preparation for helper removal (Thierry)
Cc: Chunming Zhou <david1.zhou@amd.com>
Cc: Adam Jackson <ajax@redhat.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Kangjie Lu <kjlu@umn.edu>
Cc: Mihail Atanassov <mihail.atanassov@arm.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20191024155535.GA10294@art_vandelay
Diffstat (limited to 'drivers/gpu/drm/tegra/dp.c')
| -rw-r--r-- | drivers/gpu/drm/tegra/dp.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/drivers/gpu/drm/tegra/dp.c b/drivers/gpu/drm/tegra/dp.c new file mode 100644 index 000000000000..50ba967ebcbd --- /dev/null +++ b/drivers/gpu/drm/tegra/dp.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright (C) 2013-2019 NVIDIA Corporation + * Copyright (C) 2015 Rob Clark + */ + +#include <drm/drm_dp_helper.h> + +#include "dp.h" + +/** + * drm_dp_link_probe() - probe a DisplayPort link for capabilities + * @aux: DisplayPort AUX channel + * @link: pointer to structure in which to return link capabilities + * + * The structure filled in by this function can usually be passed directly + * into drm_dp_link_power_up() and drm_dp_link_configure() to power up and + * configure the link based on the link's capabilities. + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link) +{ + u8 values[3]; + int err; + + memset(link, 0, sizeof(*link)); + + err = drm_dp_dpcd_read(aux, DP_DPCD_REV, values, sizeof(values)); + if (err < 0) + return err; + + link->revision = values[0]; + link->rate = drm_dp_bw_code_to_link_rate(values[1]); + link->num_lanes = values[2] & DP_MAX_LANE_COUNT_MASK; + + if (values[2] & DP_ENHANCED_FRAME_CAP) + link->capabilities |= DP_LINK_CAP_ENHANCED_FRAMING; + + return 0; +} + +/** + * drm_dp_link_power_up() - power up a DisplayPort link + * @aux: DisplayPort AUX channel + * @link: pointer to a structure containing the link configuration + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link) +{ + u8 value; + int err; + + /* DP_SET_POWER register is only available on DPCD v1.1 and later */ + if (link->revision < 0x11) + return 0; + + err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); + if (err < 0) + return err; + + value &= ~DP_SET_POWER_MASK; + value |= DP_SET_POWER_D0; + + err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); + if (err < 0) + return err; + + /* + * According to the DP 1.1 specification, a "Sink Device must exit the + * power saving state within 1 ms" (Section 2.5.3.1, Table 5-52, "Sink + * Control Field" (register 0x600). + */ + usleep_range(1000, 2000); + + return 0; +} + +/** + * drm_dp_link_power_down() - power down a DisplayPort link + * @aux: DisplayPort AUX channel + * @link: pointer to a structure containing the link configuration + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link) +{ + u8 value; + int err; + + /* DP_SET_POWER register is only available on DPCD v1.1 and later */ + if (link->revision < 0x11) + return 0; + + err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); + if (err < 0) + return err; + + value &= ~DP_SET_POWER_MASK; + value |= DP_SET_POWER_D3; + + err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); + if (err < 0) + return err; + + return 0; +} + +/** + * drm_dp_link_configure() - configure a DisplayPort link + * @aux: DisplayPort AUX channel + * @link: pointer to a structure containing the link configuration + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link) +{ + u8 values[2]; + int err; + + values[0] = drm_dp_link_rate_to_bw_code(link->rate); + values[1] = link->num_lanes; + + if (link->capabilities & DP_LINK_CAP_ENHANCED_FRAMING) + values[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN; + + err = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, values, sizeof(values)); + if (err < 0) + return err; + + return 0; +} |
