From aa9145c4fa283da09adb88d65784a39bc454b239 Mon Sep 17 00:00:00 2001 From: Animesh Manna Date: Wed, 13 May 2015 22:13:29 +0530 Subject: drm/i915/skl: Documentation for CSR firmware Added docbook info regarding context save and restore (CSR) firmware support added from gen9 onwards to drive newly added DMC (Display microcontroller) in display engine. v1: Initial version as RFC. v2: Used "DOC:" tag for csr description based on review comment from Daniel. Signed-off-by: Animesh Manna Signed-off-by: A.Sunil Kamath Signed-off-by: Daniel Vetter --- Documentation/DocBook/drm.tmpl | 7 +++++- drivers/gpu/drm/i915/intel_csr.c | 53 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+), 1 deletion(-) diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl index 7c68ecc800a1..b6fc354a20e7 100644 --- a/Documentation/DocBook/drm.tmpl +++ b/Documentation/DocBook/drm.tmpl @@ -4153,6 +4153,12 @@ int num_ioctls; + + + CSR firmware support for DMC +!Pdrivers/gpu/drm/i915/intel_csr.c csr support for dmc +!Idrivers/gpu/drm/i915/intel_csr.c + @@ -4204,7 +4210,6 @@ int num_ioctls; !Idrivers/gpu/drm/i915/i915_gem_shrinker.c - Tracing diff --git a/drivers/gpu/drm/i915/intel_csr.c b/drivers/gpu/drm/i915/intel_csr.c index 9311cddb86e6..5cb8cc18994a 100644 --- a/drivers/gpu/drm/i915/intel_csr.c +++ b/drivers/gpu/drm/i915/intel_csr.c @@ -25,6 +25,22 @@ #include "i915_drv.h" #include "i915_reg.h" +/** + * DOC: csr support for dmc + * + * Display Context Save and Restore (CSR) firmware support added from gen9 + * onwards to drive newly added DMC (Display microcontroller) in display + * engine to save and restore the state of display engine when it enter into + * low-power state and comes back to normal. + * + * Firmware loading status will be one of the below states: FW_UNINITIALIZED, + * FW_LOADED, FW_FAILED. + * + * Once the firmware is written into the registers status will be moved from + * FW_UNINITIALIZED to FW_LOADED and for any erroneous condition status will + * be moved to FW_FAILED. + */ + #define I915_CSR_SKL "i915/skl_dmc_ver4.bin" MODULE_FIRMWARE(I915_CSR_SKL); @@ -183,6 +199,14 @@ static char intel_get_substepping(struct drm_device *dev) return -ENODATA; } +/** + * intel_csr_load_status_get() - to get firmware loading status. + * @dev_priv: i915 device. + * + * This function helps to get the firmware loading status. + * + * Return: Firmware loading status. + */ enum csr_state intel_csr_load_status_get(struct drm_i915_private *dev_priv) { enum csr_state state; @@ -194,6 +218,13 @@ enum csr_state intel_csr_load_status_get(struct drm_i915_private *dev_priv) return state; } +/** + * intel_csr_load_status_set() - help to set firmware loading status. + * @dev_priv: i915 device. + * @state: enumeration of firmware loading status. + * + * Set the firmware loading status. + */ void intel_csr_load_status_set(struct drm_i915_private *dev_priv, enum csr_state state) { @@ -202,6 +233,14 @@ void intel_csr_load_status_set(struct drm_i915_private *dev_priv, mutex_unlock(&dev_priv->csr_lock); } +/** + * intel_csr_load_program() - write the firmware from memory to register. + * @dev: drm device. + * + * CSR firmware is read from a .bin file and kept in internal memory one time. + * Everytime display comes back from low power state this function is called to + * copy the firmware from internal memory to registers. + */ void intel_csr_load_program(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; @@ -359,6 +398,13 @@ out: release_firmware(fw); } +/** + * intel_csr_ucode_init() - initialize the firmware loading. + * @dev: drm device. + * + * This function is called at the time of loading the display driver to read + * firmware from a .bin file and copied into a internal memory. + */ void intel_csr_ucode_init(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; @@ -393,6 +439,13 @@ void intel_csr_ucode_init(struct drm_device *dev) } } +/** + * intel_csr_ucode_fini() - unload the CSR firmware. + * @dev: drm device. + * + * Firmmware unloading includes freeing the internal momory and reset the + * firmware loading status. + */ void intel_csr_ucode_fini(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; -- cgit v1.2.3-59-g8ed1b