drm/i915: Software workaround for getting the HW status of DSI Port C on BYT

Due to hardware limitations on BYT, MIPI Port C DPI Enable bit
does not get set. To check whether DSI Port C was enabled in BIOS,
check the Pipe B enable bit for DSI Port C. In hardware, DSI Port C
is linked with Pipe B.

v2: Addressed review comments of Jani, Nikula
    - Used platform checks for this software workaround for BYT

Signed-off-by: Gaurav K Singh <gaurav.k.singh@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Gaurav K Singh 2014-12-09 10:59:20 +05:30 committed by Daniel Vetter
parent bf344e8090
commit c0beefd29f
1 changed files with 17 additions and 5 deletions

View File

@ -398,8 +398,10 @@ static bool intel_dsi_get_hw_state(struct intel_encoder *encoder,
enum pipe *pipe)
{
struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
struct drm_device *dev = encoder->base.dev;
enum intel_display_power_domain power_domain;
u32 port_ctl, func;
u32 dpi_enabled, func;
enum port port;
DRM_DEBUG_KMS("\n");
@ -409,13 +411,23 @@ static bool intel_dsi_get_hw_state(struct intel_encoder *encoder,
return false;
/* XXX: this only works for one DSI output */
for_each_dsi_port(port, (1 << PORT_A) | (1 << PORT_C)) {
port_ctl = I915_READ(MIPI_PORT_CTRL(port));
for_each_dsi_port(port, intel_dsi->ports) {
func = I915_READ(MIPI_DSI_FUNC_PRG(port));
dpi_enabled = I915_READ(MIPI_PORT_CTRL(port)) &
DPI_ENABLE;
if ((port_ctl & DPI_ENABLE) || (func & CMD_MODE_DATA_WIDTH_MASK)) {
/* Due to some hardware limitations on BYT, MIPI Port C DPI
* Enable bit does not get set. To check whether DSI Port C
* was enabled in BIOS, check the Pipe B enable bit
*/
if (IS_VALLEYVIEW(dev) && !IS_CHERRYVIEW(dev) &&
(port == PORT_C))
dpi_enabled = I915_READ(PIPECONF(PIPE_B)) &
PIPECONF_ENABLE;
if (dpi_enabled || (func & CMD_MODE_DATA_WIDTH_MASK)) {
if (I915_READ(MIPI_DEVICE_READY(port)) & DEVICE_READY) {
*pipe = port == PORT_A ? PIPE_A : PIPE_C;
*pipe = port == PORT_A ? PIPE_A : PIPE_B;
return true;
}
}