usb: dwc3: update documentation

No functional changes, just making sure we can use these for ReST docs
later.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

4 files changed, 124 insertions, 65 deletions

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 6f6294dbea9d..ea910acb4bb0 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1,4 +1,4 @@
-/**
+/*
  * core.h - DesignWare USB3 DRD Core Header
  *
  * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
@@ -523,7 +523,6 @@ struct dwc3_event_buffer {
  * @trb_pool_dma: dma address of @trb_pool
  * @trb_enqueue: enqueue 'pointer' into TRB array
  * @trb_dequeue: dequeue 'pointer' into TRB array
- * @desc: usb_endpoint_descriptor pointer
  * @dwc: pointer to DWC controller
  * @saved_state: ep state saved during hibernation
  * @flags: endpoint flags (wedged, stalled, ...)
@@ -665,7 +664,7 @@ enum dwc3_link_state {
  * @bpl: DW0-3
  * @bph: DW4-7
  * @size: DW8-B
- * @trl: DWC-F
+ * @ctrl: DWC-F
  */
 struct dwc3_trb {
 	u32		bpl;
@@ -675,16 +674,16 @@ struct dwc3_trb {
 } __packed;
 
 /**
- * dwc3_hwparams - copy of HWPARAMS registers
- * @hwparams0 - GHWPARAMS0
- * @hwparams1 - GHWPARAMS1
- * @hwparams2 - GHWPARAMS2
- * @hwparams3 - GHWPARAMS3
- * @hwparams4 - GHWPARAMS4
- * @hwparams5 - GHWPARAMS5
- * @hwparams6 - GHWPARAMS6
- * @hwparams7 - GHWPARAMS7
- * @hwparams8 - GHWPARAMS8
+ * struct dwc3_hwparams - copy of HWPARAMS registers
+ * @hwparams0: GHWPARAMS0
+ * @hwparams1: GHWPARAMS1
+ * @hwparams2: GHWPARAMS2
+ * @hwparams3: GHWPARAMS3
+ * @hwparams4: GHWPARAMS4
+ * @hwparams5: GHWPARAMS5
+ * @hwparams6: GHWPARAMS6
+ * @hwparams7: GHWPARAMS7
+ * @hwparams8: GHWPARAMS8
  */
 struct dwc3_hwparams {
 	u32	hwparams0;
@@ -731,7 +730,8 @@ struct dwc3_hwparams {
  * @unaligned: true for OUT endpoints with length not divisible by maxp
  * @direction: IN or OUT direction flag
  * @mapped: true when request has been dma-mapped
- * @queued: true when request has been queued to HW
+ * @started: request is started
+ * @zero: wants a ZLP
  */
 struct dwc3_request {
 	struct usb_request	request;
@@ -762,17 +762,23 @@ struct dwc3_scratchpad_array {
 
 /**
  * struct dwc3 - representation of our controller
- * @drd_work - workqueue used for role swapping
+ * @drd_work: workqueue used for role swapping
  * @ep0_trb: trb which is used for the ctrl_req
+ * @bounce: address of bounce buffer
+ * @scratchbuf: address of scratch buffer
  * @setup_buf: used while precessing STD USB requests
- * @ep0_trb: dma address of ep0_trb
+ * @ep0_trb_addr: dma address of @ep0_trb
+ * @bounce_addr: dma address of @bounce
  * @ep0_usb_req: dummy req used while handling STD USB requests
  * @scratch_addr: dma address of scratchbuf
  * @ep0_in_setup: one control transfer is completed and enter setup phase
  * @lock: for synchronizing
  * @dev: pointer to our struct device
+ * @sysdev: pointer to the DMA-capable device
  * @xhci: pointer to our xHCI child
- * @event_buffer_list: a list of event buffers
+ * @xhci_resources: struct resources for our @xhci child
+ * @ev_buf: struct dwc3_event_buffer pointer
+ * @eps: endpoint array
  * @gadget: device side representation of the peripheral controller
  * @gadget_driver: pointer to the gadget driver
  * @regs: base address for our registers
@@ -796,8 +802,6 @@ struct dwc3_scratchpad_array {
  * @usb2_generic_phy: pointer to USB2 PHY
  * @usb3_generic_phy: pointer to USB3 PHY
  * @ulpi: pointer to ulpi interface
- * @dcfg: saved contents of DCFG register
- * @gctl: saved contents of GCTL register
  * @isoch_delay: wValue from Set Isochronous Delay request;
  * @u2sel: parameter from Set SEL request.
  * @u2pel: parameter from Set SEL request.
@@ -831,7 +835,6 @@ struct dwc3_scratchpad_array {
  * @pending_events: true when we have pending IRQs to be handled
  * @pullups_connected: true when Run/Stop bit is set
  * @setup_packet_pending: true when there's a Setup Packet in FIFO. Workaround
- * @start_config_issued: true when StartConfig command has been issued
  * @three_stage_setup: set if we perform a three phase setup
  * @usb3_lpm_capable: set if hadrware supports Link Power Management
  * @disable_scramble_quirk: set if we enable the disable scramble quirk
@@ -846,6 +849,7 @@ struct dwc3_scratchpad_array {
  * @dis_u2_susphy_quirk: set if we disable usb2 suspend phy
  * @dis_enblslpm_quirk: set if we clear enblslpm in GUSB2PHYCFG,
  *                      disabling the suspend signal to the PHY.
+ * @dis_rxdet_inp3_quirk: set if we disable Rx.Detect in P3
  * @dis_u2_freeclk_exists_quirk : set if we clear u2_freeclk_exists
  *			in GUSB2PHYCFG, specify that USB2 PHY doesn't
  *			provide a free-running PHY clock.
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index a78c78e7a8c3..8cfce8425101 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -1,4 +1,4 @@
-/**
+/*
  * ep0.c - DesignWare USB3 DRD Controller Endpoint 0 Handling
  *
  * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 011ac3ccfbe7..e4e872c703f1 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1,4 +1,4 @@
-/**
+/*
  * gadget.c - DesignWare USB3 DRD Controller Gadget Framework Link
  *
  * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
@@ -36,13 +36,12 @@
 #include "io.h"
 
 /**
- * dwc3_gadget_set_test_mode - Enables USB2 Test Modes
+ * dwc3_gadget_set_test_mode - enables usb2 test modes
  * @dwc: pointer to our context structure
  * @mode: the mode to set (J, K SE0 NAK, Force Enable)
  *
- * Caller should take care of locking. This function will
- * return 0 on success or -EINVAL if wrong Test Selector
- * is passed
+ * Caller should take care of locking. This function will return 0 on
+ * success or -EINVAL if wrong Test Selector is passed.
  */
 int dwc3_gadget_set_test_mode(struct dwc3 *dwc, int mode)
 {
@@ -69,7 +68,7 @@ int dwc3_gadget_set_test_mode(struct dwc3 *dwc, int mode)
 }
 
 /**
- * dwc3_gadget_get_link_state - Gets current state of USB Link
+ * dwc3_gadget_get_link_state - gets current state of usb link
  * @dwc: pointer to our context structure
  *
  * Caller should take care of locking. This function will
@@ -85,7 +84,7 @@ int dwc3_gadget_get_link_state(struct dwc3 *dwc)
 }
 
 /**
- * dwc3_gadget_set_link_state - Sets USB Link to a particular State
+ * dwc3_gadget_set_link_state - sets usb link to a particular state
  * @dwc: pointer to our context structure
  * @state: the state to put link into
  *
@@ -143,8 +142,8 @@ int dwc3_gadget_set_link_state(struct dwc3 *dwc, enum dwc3_link_state state)
 }
 
 /**
- * dwc3_ep_inc_trb() - Increment a TRB index.
- * @index - Pointer to the TRB index to increment.
+ * dwc3_ep_inc_trb - increment a trb index.
+ * @index: Pointer to the TRB index to increment.
  *
  * The index should never point to the link TRB. After incrementing,
  * if it is point to the link TRB, wrap around to the beginning. The
@@ -157,16 +156,34 @@ static void dwc3_ep_inc_trb(u8 *index)
 		*index = 0;
 }
 
+/**
+ * dwc3_ep_inc_enq - increment endpoint's enqueue pointer
+ * @dep: The endpoint whose enqueue pointer we're incrementing
+ */
 static void dwc3_ep_inc_enq(struct dwc3_ep *dep)
 {
 	dwc3_ep_inc_trb(&dep->trb_enqueue);
 }
 
+/**
+ * dwc3_ep_inc_deq - increment endpoint's dequeue pointer
+ * @dep: The endpoint whose enqueue pointer we're incrementing
+ */
 static void dwc3_ep_inc_deq(struct dwc3_ep *dep)
 {
 	dwc3_ep_inc_trb(&dep->trb_dequeue);
 }
 
+/**
+ * dwc3_gadget_giveback - call struct usb_request's ->complete callback
+ * @dep: The endpoint to whom the request belongs to
+ * @req: The request we're giving back
+ * @status: completion code for the request
+ *
+ * Must be called with controller's lock held and interrupts disabled. This
+ * function will unmap @req and call its ->complete() callback to notify upper
+ * layers that it has completed.
+ */
 void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
 		int status)
 {
@@ -193,6 +210,15 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
 		pm_runtime_put(dwc->dev);
 }
 
+/**
+ * dwc3_send_gadget_generic_command - issue a generic command for the controller
+ * @dwc: pointer to the controller context
+ * @cmd: the command to be issued
+ * @param: command parameter
+ *
+ * Caller should take care of locking. Issue @cmd with a given @param to @dwc
+ * and wait for its completion.
+ */
 int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned cmd, u32 param)
 {
 	u32		timeout = 500;
@@ -225,6 +251,15 @@ int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned cmd, u32 param)
 
 static int __dwc3_gadget_wakeup(struct dwc3 *dwc);
 
+/**
+ * dwc3_send_gadget_ep_cmd - issue an endpoint command
+ * @dep: the endpoint to which the command is going to be issued
+ * @cmd: the command to be issued
+ * @params: parameters to the command
+ *
+ * Caller should handle locking. This function will issue @cmd with given
+ * @params to @dep and wait for its completion.
+ */
 int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned cmd,
 		struct dwc3_gadget_ep_cmd_params *params)
 {
@@ -422,36 +457,38 @@ static void dwc3_free_trb_pool(struct dwc3_ep *dep)
 static int dwc3_gadget_set_xfer_resource(struct dwc3 *dwc, struct dwc3_ep *dep);
 
 /**
- * dwc3_gadget_start_config - Configure EP resources
+ * dwc3_gadget_start_config - configure ep resources
  * @dwc: pointer to our controller context structure
  * @dep: endpoint that is being enabled
  *
- * The assignment of transfer resources cannot perfectly follow the
- * data book due to the fact that the controller driver does not have
- * all knowledge of the configuration in advance. It is given this
- * information piecemeal by the composite gadget framework after every
- * SET_CONFIGURATION and SET_INTERFACE. Trying to follow the databook
- * programming model in this scenario can cause errors. For two
- * reasons:
+ * Issue a %DWC3_DEPCMD_DEPSTARTCFG command to @dep. After the command's
+ * completion, it will set Transfer Resource for all available endpoints.
  *
- * 1) The databook says to do DEPSTARTCFG for every SET_CONFIGURATION
- * and SET_INTERFACE (8.1.5). This is incorrect in the scenario of
- * multiple interfaces.
+ * The assignment of transfer resources cannot perfectly follow the data book
+ * due to the fact that the controller driver does not have all knowledge of the
+ * configuration in advance. It is given this information piecemeal by the
+ * composite gadget framework after every SET_CONFIGURATION and
+ * SET_INTERFACE. Trying to follow the databook programming model in this
+ * scenario can cause errors. For two reasons:
  *
- * 2) The databook does not mention doing more DEPXFERCFG for new
+ * 1) The databook says to do %DWC3_DEPCMD_DEPSTARTCFG for every
+ * %USB_REQ_SET_CONFIGURATION and %USB_REQ_SET_INTERFACE (8.1.5). This is
+ * incorrect in the scenario of multiple interfaces.
+ *
+ * 2) The databook does not mention doing more %DWC3_DEPCMD_DEPXFERCFG for new
  * endpoint on alt setting (8.1.6).
  *
  * The following simplified method is used instead:
  *
- * All hardware endpoints can be assigned a transfer resource and this
- * setting will stay persistent until either a core reset or
- * hibernation. So whenever we do a DEPSTARTCFG(0) we can go ahead and
- * do DEPXFERCFG for every hardware endpoint as well. We are
+ * All hardware endpoints can be assigned a transfer resource and this setting
+ * will stay persistent until either a core reset or hibernation. So whenever we
+ * do a %DWC3_DEPCMD_DEPSTARTCFG(0) we can go ahead and do
+ * %DWC3_DEPCMD_DEPXFERCFG for every hardware endpoint as well. We are
  * guaranteed that there are as many transfer resources as endpoints.
  *
- * This function is called for each endpoint when it is being enabled
- * but is triggered only when called for EP0-out, which always happens
- * first, and which should only happen in one of the above conditions.
+ * This function is called for each endpoint when it is being enabled but is
+ * triggered only when called for EP0-out, which always happens first, and which
+ * should only happen in one of the above conditions.
  */
 static int dwc3_gadget_start_config(struct dwc3 *dwc, struct dwc3_ep *dep)
 {
@@ -569,11 +606,13 @@ static int dwc3_gadget_set_xfer_resource(struct dwc3 *dwc, struct dwc3_ep *dep)
 }
 
 /**
- * __dwc3_gadget_ep_enable - Initializes a HW endpoint
+ * __dwc3_gadget_ep_enable - initializes a hw endpoint
  * @dep: endpoint to be initialized
- * @desc: USB Endpoint Descriptor
+ * @modify: if true, modify existing endpoint configuration
+ * @restore: if true, restore endpoint configuration from scratch buffer
  *
- * Caller should take care of locking
+ * Caller should take care of locking. Execute all necessary commands to
+ * initialize a HW endpoint so it can be used by a gadget driver.
  */
 static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep,
 		bool modify, bool restore)
@@ -685,11 +724,13 @@ static void dwc3_remove_requests(struct dwc3 *dwc, struct dwc3_ep *dep)
 }
 
 /**
- * __dwc3_gadget_ep_disable - Disables a HW endpoint
+ * __dwc3_gadget_ep_disable - disables a hw endpoint
  * @dep: the endpoint to disable
  *
- * This function also removes requests which are currently processed ny the
- * hardware and those which are not yet scheduled.
+ * This function undoes what __dwc3_gadget_ep_enable did and also removes
+ * requests which are currently being processed by the hardware and those which
+ * are not yet scheduled.
+ *
  * Caller should take care of locking.
  */
 static int __dwc3_gadget_ep_disable(struct dwc3_ep *dep)
@@ -932,7 +973,7 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
 }
 
 /**
- * dwc3_ep_prev_trb() - Returns the previous TRB in the ring
+ * dwc3_ep_prev_trb - returns the previous TRB in the ring
  * @dep: The endpoint with the TRB ring
  * @index: The index of the current TRB in the ring
  *
@@ -1729,8 +1770,8 @@ static irqreturn_t dwc3_interrupt(int irq, void *_dwc);
 static irqreturn_t dwc3_thread_interrupt(int irq, void *_dwc);
 
 /**
- * dwc3_gadget_setup_nump - Calculate and initialize NUMP field of DCFG
- * dwc: pointer to our context structure
+ * dwc3_gadget_setup_nump - calculate and initialize NUMP field of %DWC3_DCFG
+ * @dwc: pointer to our context structure
  *
  * The following looks like complex but it's actually very simple. In order to
  * calculate the number of packets we can burst at once on OUT transfers, we're
@@ -1789,7 +1830,7 @@ static int __dwc3_gadget_start(struct dwc3 *dwc)
 	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
 	reg &= ~(DWC3_DCFG_SPEED_MASK);
 
-	/**
+	/*
 	 * WORKAROUND: DWC3 revision < 2.20a have an issue
 	 * which would cause metastability state on Run/Stop
 	 * bit if we try to force the IP to USB2-only mode.
@@ -2859,7 +2900,7 @@ static void dwc3_gadget_hibernation_interrupt(struct dwc3 *dwc,
 {
 	unsigned int is_ss = evtinfo & BIT(4);
 
-	/**
+	/*
 	 * WORKAROUND: DWC3 revison 2.20a with hibernation support
 	 * have a known issue which can cause USB CV TD.9.23 to fail
 	 * randomly.
@@ -3089,7 +3130,7 @@ out:
 }
 
 /**
- * dwc3_gadget_init - Initializes gadget related registers
+ * dwc3_gadget_init - initializes gadget related registers
  * @dwc: pointer to our controller context structure
  *
  * Returns 0 on success otherwise negative errno.
diff --git a/drivers/usb/dwc3/gadget.h b/drivers/usb/dwc3/gadget.h
index e4602d0e515b..4a3227543255 100644
--- a/drivers/usb/dwc3/gadget.h
+++ b/drivers/usb/dwc3/gadget.h
@@ -1,4 +1,4 @@
-/**
+/*
  * gadget.h - DesignWare USB3 DRD Gadget Header
  *
  * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
@@ -60,11 +60,25 @@ struct dwc3;
 
 #define to_dwc3_request(r)	(container_of(r, struct dwc3_request, request))
 
+/**
+ * next_request - gets the next request on the given list
+ * @list: the request list to operate on
+ *
+ * Caller should take care of locking. This function return %NULL or the first
+ * request available on @list.
+ */
 static inline struct dwc3_request *next_request(struct list_head *list)
 {
 	return list_first_entry_or_null(list, struct dwc3_request, list);
 }
 
+/**
+ * dwc3_gadget_move_started_request - move @req to the started_list
+ * @req: the request to be moved
+ *
+ * Caller should take care of locking. This function will move @req from its
+ * current list to the endpoint's started_list.
+ */
 static inline void dwc3_gadget_move_started_request(struct dwc3_request *req)
 {
 	struct dwc3_ep		*dep = req->dep;
@@ -87,10 +101,10 @@ int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol);
 
 /**
  * dwc3_gadget_ep_get_transfer_index - Gets transfer index from HW
- * @dwc: DesignWare USB3 Pointer
- * @number: DWC endpoint number
+ * @dep: dwc3 endpoint
  *
- * Caller should take care of locking
+ * Caller should take care of locking. Returns the transfer resource
+ * index for a given endpoint.
  */
 static inline u32 dwc3_gadget_ep_get_transfer_index(struct dwc3_ep *dep)
 {