diff --git a/drivers/gpu/nvgpu/include/nvgpu/acr.h b/drivers/gpu/nvgpu/include/nvgpu/acr.h
index 322f60975..667533e99 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/acr.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/acr.h
@@ -23,20 +23,201 @@
 #ifndef NVGPU_ACR_H
 #define NVGPU_ACR_H
 
+/**
+ * @file
+ * @page unit-acr Unit ACR(Access Controlled Regions)
+ *
+ * Acronyms
+ * ========
+ * ACR     - Access Controlled Regions
+ * ACR HS  - Access Controlled Regions Heavy-Secure ucode
+ * FB      - Frame Buffer
+ * non-WPR - non-Write Protected Region
+ * WPR     - Write Protected Region
+ * LS      - Light-Secure
+ * HS      - Heavy-Secure
+ * Falcon  - Fast Logic CONtroller
+ * BLOB    - Binary Large OBject
+ *
+ * Overview
+ * ========
+ * The ACR unit is responsible for GPU secure boot. ACR unit divides its task
+ * into two stages as below,
+ *
+ * + Blob construct:
+ *   ACR unit creates LS ucode blob in system/FB's non-WPR memory. LS ucodes
+ *   will be read from filesystem and added to blob as per ACR unit static
+ *   config data. ACR unit static config data is set based on current chip.
+ *   LS ucodes blob is required by the ACR HS ucode to authenticate & load LS
+ *   ucode on to respective engine's LS Falcon.
+ *
+ * + ACR HS ucode load & bootstrap:
+ *   ACR HS ucode is responsible for authenticating self(HS) & LS ucode.
+ *
+ *   ACR HS ucode is read from the filesystem based on the chip-id by the ACR
+ *   unit. Read ACR HS ucode is loaded onto PMU/SEC2/GSP engines Falcon to
+ *   bootstrap ACR HS ucode. ACR HS ucode does self-authentication using H/W
+ *   based HS authentication methodology. Once authenticated the ACR HS ucode
+ *   starts executing on the falcon.
+ *
+ *   Upon successful ACR HS ucode boot, ACR HS ucode performs a sanity check on
+ *   WPR memory. If the WPR sanity check passes, then ACR HS ucode copies LS
+ *   ucodes from system/FB's non-WPR memory to system/FB's WPR memory. The
+ *   purpose of copying LS ucode to WPR memory is to protect ucodes from
+ *   modification or tampering. The next step is to authenticate LS ucodes
+ *   present in WPR memory using S/W based authentication methodology. If the
+ *   LS ucode authentication passed, then ACR HS ucode loads LS ucode on to
+ *   respective LS Falcons. If any of the LS ucode authentications fail, then
+ *   ACR HS ucode updates error details in Falcon mailbox-0/1 & halts its
+ *   execution. In the passing case, ACR HS ucode halts & updates mailbox-0 with
+ *   ACR_OK(0x0) status.
+ *
+ *   ACR unit waits for ACR HS ucode to halt & checks for mailbox-0/1 to
+ *   determine the status of ACR HS ucode. If there was an error then ACR unit
+ *   returns an error else success.
+ *
+ * The ACR unit is a s/w unit which doesn't access any h/w registers by itself.
+ * It depends on below units to access H/W resource to complete its task.
+ *
+ *   + PMU, SEC2 & GSP unit to access & load ucode on Engines Falcon.
+ *   + Falcon unit to control/access Engines(PMU, SEC2 & GSP) Falcon to load &
+ *     execute HS ucode
+ *   + MM unit to fetch non-WPR/WPR info, allocate & read/write data in
+ *     non-WPR memory.
+ *
+ * Data Structures
+ * ===============
+ *
+ * There are no data structures exposed outside of ACR unit in nvgpu.
+ *
+ * Static Design
+ * =============
+ *
+ * ACR Initialization
+ * ------------------
+ * ACR initialization happens as part of early NVGPU poweron sequence by calling
+ * nvgpu_acr_init(). At ACR init stage memory gets allocated for ACR unit's
+ * private data struct. The data struct holds static properties and ops of the
+ * ACR unit and is populated based on the detected chip. These static properties
+ * and ops will be used by blob-construct and load/bootstrap stage of ACR unit.
+ *
+ * ACR Teardown
+ * ------------
+ * The function nvgpu_acr_free() is called from nvgpu_remove() as part of
+ * poweroff sequence to clear and free the memory space allocated for ACR unit.
+ *
+ * External APIs
+ * -------------
+ *   + nvgpu_acr_init()
+ *   + nvgpu_acr_free()
+ *
+ * Dynamic Design
+ * ==============
+ *
+ * After ACR unit init completion, the properties and ops of the ACR unit are
+ * set to perform blob construction in non-wpr memory & load/bootstrap of HS ACR
+ * ucode on specific engine's Falcon.
+ *
+ * Blob construct
+ * --------------
+ * The ACR unit creates blob for LS ucodes in nop-WPR memory & update
+ * WPR/LS-ucode details in interface which is part of non-wpr region. Interface
+ * will be accessed by ACR HS ucode to know in detail about WPR & LS ucodes.
+ *
+ * Load/Bootstrap ACR HS ucode
+ * ---------------------------
+ * The ACR unit loads ACR HS ucode onto PMU/SEC2/GSP engines Falcon as per
+ * static config data & performs a bootstrap.
+ *
+ * ACR HS ucode does self-authentication using H/W based HS authentication
+ * methodology. Once authenticated the ACR HS ucode starts executing on the
+ * falcon. Upon successful ACR HS ucode boot, ACR HS ucode copies LS ucodes
+ * from non-WPR memory to WPR memory. The next step is to authenticate LS ucodes
+ * present in WPR memory and loads LS ucode on to respective LS Falcons.
+ *
+ * The ACR unit waits for ACR HS to halt within predefined timeout. Upon ACR HS
+ * ucode halt, the ACR unit checks mailbox-0/1 to determine the status of ACR
+ * HS ucode. If there is an error then ACR unit returns error else success.
+ *
+ * External APIs
+ * -------------
+ *   + nvgpu_acr_construct_execute()
+ *   + nvgpu_acr_is_lsf_lazy_bootstrap()
+ *   + nvgpu_acr_bootstrap_hs_acr()
+ *
+ */
+
 struct gk20a;
 struct nvgpu_falcon;
 struct nvgpu_firmware;
 struct nvgpu_acr;
 
+/**
+ * @brief ACR initialization to allocate memory for ACR unit & set static
+ *        properties and ops for LS ucode blob construction as well as for
+ *        ACR HS ucode bootstrap.
+ *
+ * @param g   [in] The GPU driver struct.
+ * @param acr [in] The ACR private data struct.
+ *
+ * Initializes ACR unit private data struct in the GPU driver based on current
+ * chip. Allocate memory for #nvgpu_acr data struct & sets the static properties
+ * and ops for LS ucode blob construction as well as for ACR HS ucode bootstrap.
+ *
+ * @return 0 in case of success, < 0 in case of failure.
+ */
 int nvgpu_acr_init(struct gk20a *g, struct nvgpu_acr **acr);
+
 #ifdef CONFIG_NVGPU_DGPU
 int nvgpu_acr_alloc_blob_prerequisite(struct gk20a *g, struct nvgpu_acr *acr,
 	size_t size);
 int nvgpu_acr_self_hs_load_bootstrap(struct gk20a *g, struct nvgpu_falcon *flcn,
 	struct nvgpu_firmware *hs_fw, u32 timeout);
 #endif
+
+/**
+ * @brief Construct blob of LS ucode's in non-wpr memory. Load and bootstrap HS
+ *        ACR ucode on specified engine Falcon
+ *
+ * @param g   [in] The GPU driver struct.
+ * @param acr [in] The ACR private data struct
+ *
+ * Construct blob of LS ucode in non-wpr memory. Allocation happens in non-WPR
+ * system/FB memory based on type of GPU iGPU/dGPU currently in execution. Next,
+ * ACR unit loads & bootstrap ACR HS ucode on specified engine Falcon.
+ *
+ * @return 0 in case of success, < 0 in case of failure.
+ */
 int nvgpu_acr_construct_execute(struct gk20a *g, struct nvgpu_acr *acr);
+
+/**
+ * @brief Read, Load and Bootstrap HS ACR ucode on Engine's Falcon.
+ *
+ * @param g   [in] The GPU driver struct.
+ * @param acr [in] The ACR private data struct
+ *
+ * Load HS ucode on specified engine Falcon as per static config data & does
+ * bootstrap to self-HS-authenticate(H/W based) followed by ACR HS execution.
+ * ACR unit waits for ACR HS ucode to halt & check mailbox-0/1 to know the
+ * status of ACR HS ucode, if there is an error then ACR unit returns an error
+ * else success.
+ *
+ * @return 0 in case of success, < 0 in case of failure.
+ */
 int nvgpu_acr_bootstrap_hs_acr(struct gk20a *g, struct nvgpu_acr *acr);
+
+/**
+ * @brief Chek if ls-Falcon lazy-bootstrap status to load & bootstrap from
+ *        LS-RTOS or not
+ *
+ * @param g   [in] The GPU driver struct.
+ * @param acr [in] The ACR private data struct
+ *
+ * Chek if ls-Falcon lazy-bootstrap status to load & bootstrap from
+ * LS-RTOS or not.
+ *
+ * @return True in case of success, False in case of failure.
+ */
 bool nvgpu_acr_is_lsf_lazy_bootstrap(struct gk20a *g, struct nvgpu_acr *acr,
 	u32 falcon_id);
 
diff --git a/drivers/gpu/nvgpu/include/nvgpu/gk20a.h b/drivers/gpu/nvgpu/include/nvgpu/gk20a.h
index 36c18cd6b..0a832c60d 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/gk20a.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/gk20a.h
@@ -41,6 +41,7 @@
  *   - @ref unit-init
  *   - @ref unit-falcon
  *   - @ref unit-os_utils
+ *   - @ref unit-acr
  *   - Etc, etc.
  *
  * NVGPU Software Unit Design Documentation