Commit 4d3cf5f7 authored by Ben Cahill's avatar Ben Cahill Committed by David S. Miller

iwlwifi: document Rx registers

Document Rx registers

Document Tx circular buffer base registers
Signed-off-by: default avatarBen Cahill <ben.m.cahill@intel.com>
Signed-off-by: default avatarZhu Yi <yi.zhu@intel.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent aad14143
......@@ -1286,7 +1286,7 @@ enum {
/* Flow Handler Definitions */
/****************************/
/*
/**
* This I/O area is directly read/writable by driver (e.g. Linux uses writel())
* Addresses are offsets from device's PCI hardware base address.
*/
......@@ -1313,35 +1313,193 @@ enum {
#define IWL_FH_KW_MEM_ADDR_REG (FH_MEM_LOWER_BOUND + 0x97C)
/* CBBC Area - Circular buffers base address cache pointers table */
/**
* TFD Circular Buffers Base (CBBC) addresses
*
* 4965 has 16 base pointer registers, one for each of 16 host-DRAM-resident
* circular buffers (CBs/queues) containing Transmit Frame Descriptors (TFDs)
* (see struct iwl_tfd_frame). These 16 pointer registers are offset by 0x04
* bytes from one another. Each TFD circular buffer in DRAM must be 256-byte
* aligned (address bits 0-7 must be 0).
*
* Bit fields in each pointer register:
* 27-0: TFD CB physical base address [35:8], must be 256-byte aligned
*/
#define FH_MEM_CBBC_LOWER_BOUND (FH_MEM_LOWER_BOUND + 0x9D0)
#define FH_MEM_CBBC_UPPER_BOUND (FH_MEM_LOWER_BOUND + 0xA10)
/* queues 0 - 15 */
/* Find TFD CB base pointer for given queue (range 0-15). */
#define FH_MEM_CBBC_QUEUE(x) (FH_MEM_CBBC_LOWER_BOUND + (x) * 0x4)
/* RSCSR Area */
/**
* Rx SRAM Control and Status Registers (RSCSR)
*
* These registers provide handshake between driver and 4965 for the Rx queue
* (this queue handles *all* command responses, notifications, Rx data, etc.
* sent from 4965 uCode to host driver). Unlike Tx, there is only one Rx
* queue, and only one Rx DMA/FIFO channel. Also unlike Tx, which can
* concatenate up to 20 DRAM buffers to form a Tx frame, each Receive Buffer
* Descriptor (RBD) points to only one Rx Buffer (RB); there is a 1:1
* mapping between RBDs and RBs.
*
* Driver must allocate host DRAM memory for the following, and set the
* physical address of each into 4965 registers:
*
* 1) Receive Buffer Descriptor (RBD) circular buffer (CB), typically with 256
* entries (although any power of 2, up to 4096, is selectable by driver).
* Each entry (1 dword) points to a receive buffer (RB) of consistent size
* (typically 4K, although 8K or 16K are also selectable by driver).
* Driver sets up RB size and number of RBDs in the CB via Rx config
* register FH_MEM_RCSR_CHNL0_CONFIG_REG.
*
* Bit fields within one RBD:
* 27-0: Receive Buffer physical address bits [35:8], 256-byte aligned
*
* Driver sets physical address [35:8] of base of RBD circular buffer
* into FH_RSCSR_CHNL0_RBDCB_BASE_REG [27:0].
*
* 2) Rx status buffer, 8 bytes, in which 4965 indicates which Rx Buffers
* (RBs) have been filled, via a "write pointer", actually the index of
* the RB's corresponding RBD within the circular buffer. Driver sets
* physical address [35:4] into FH_RSCSR_CHNL0_STTS_WPTR_REG [31:0].
*
* Bit fields in lower dword of Rx status buffer (upper dword not used
* by driver; see struct iwl4965_shared, val0):
* 31-12: Not used by driver
* 11- 0: Index of last filled Rx buffer descriptor
* (4965 writes, driver reads this value)
*
* As the driver prepares Receive Buffers (RBs) for 4965 to fill, driver must
* enter pointers to these RBs into contiguous RBD circular buffer entries,
* and update the 4965's "write" index register, FH_RSCSR_CHNL0_RBDCB_WPTR_REG.
*
* This "write" index corresponds to the *next* RBD that the driver will make
* available, i.e. one RBD past the tail of the ready-to-fill RBDs within
* the circular buffer. This value should initially be 0 (before preparing any
* RBs), should be 8 after preparing the first 8 RBs (for example), and must
* wrap back to 0 at the end of the circular buffer (but don't wrap before
* "read" index has advanced past 1! See below).
* NOTE: 4965 EXPECTS THE WRITE INDEX TO BE INCREMENTED IN MULTIPLES OF 8.
*
* As the 4965 fills RBs (referenced from contiguous RBDs within the circular
* buffer), it updates the Rx status buffer in host DRAM, 2) described above,
* to tell the driver the index of the latest filled RBD. The driver must
* read this "read" index from DRAM after receiving an Rx interrupt from 4965.
*
* The driver must also internally keep track of a third index, which is the
* next RBD to process. When receiving an Rx interrupt, driver should process
* all filled but unprocessed RBs up to, but not including, the RB
* corresponding to the "read" index. For example, if "read" index becomes "1",
* driver may process the RB pointed to by RBD 0. Depending on volume of
* traffic, there may be many RBs to process.
*
* If read index == write index, 4965 thinks there is no room to put new data.
* Due to this, the maximum number of filled RBs is 255, instead of 256. To
* be safe, make sure that there is a gap of at least 2 RBDs between "write"
* and "read" indexes; that is, make sure that there are no more than 254
* buffers waiting to be filled.
*/
#define FH_MEM_RSCSR_LOWER_BOUND (FH_MEM_LOWER_BOUND + 0xBC0)
#define FH_MEM_RSCSR_UPPER_BOUND (FH_MEM_LOWER_BOUND + 0xC00)
#define FH_MEM_RSCSR_CHNL0 (FH_MEM_RSCSR_LOWER_BOUND)
/**
* Physical base address of 8-byte Rx Status buffer.
* Bit fields:
* 31-0: Rx status buffer physical base address [35:4], must 16-byte aligned.
*/
#define FH_RSCSR_CHNL0_STTS_WPTR_REG (FH_MEM_RSCSR_CHNL0)
/**
* Physical base address of Rx Buffer Descriptor Circular Buffer.
* Bit fields:
* 27-0: RBD CD physical base address [35:8], must be 256-byte aligned.
*/
#define FH_RSCSR_CHNL0_RBDCB_BASE_REG (FH_MEM_RSCSR_CHNL0 + 0x004)
/**
* Rx write pointer (index, really!).
* Bit fields:
* 11-0: Index of driver's most recent prepared-to-be-filled RBD, + 1.
* NOTE: For 256-entry circular buffer, use only bits [7:0].
*/
#define FH_RSCSR_CHNL0_RBDCB_WPTR_REG (FH_MEM_RSCSR_CHNL0 + 0x008)
/* RCSR Area - Registers address map */
/**
* Rx Config/Status Registers (RCSR)
* Rx Config Reg for channel 0 (only channel used)
*
* Driver must initialize FH_MEM_RCSR_CHNL0_CONFIG_REG as follows for
* normal operation (see bit fields).
*
* Clearing FH_MEM_RCSR_CHNL0_CONFIG_REG to 0 turns off Rx DMA.
* Driver should poll FH_MEM_RSSR_RX_STATUS_REG for
* FH_RSSR_CHNL0_RX_STATUS_CHNL_IDLE (bit 24) before continuing.
*
* Bit fields:
* 31-30: Rx DMA channel enable: '00' off/pause, '01' pause at end of frame,
* '10' operate normally
* 29-24: reserved
* 23-20: # RBDs in circular buffer = 2^value; use "8" for 256 RBDs (normal),
* min "5" for 32 RBDs, max "12" for 4096 RBDs.
* 19-18: reserved
* 17-16: size of each receive buffer; '00' 4K (normal), '01' 8K,
* '10' 12K, '11' 16K.
* 15-14: reserved
* 13-12: IRQ destination; '00' none, '01' host driver (normal operation)
* 11- 4: timeout for closing Rx buffer and interrupting host (units 32 usec)
* typical value 0x10 (about 1/2 msec)
* 3- 0: reserved
*/
#define FH_MEM_RCSR_LOWER_BOUND (FH_MEM_LOWER_BOUND + 0xC00)
#define FH_MEM_RCSR_UPPER_BOUND (FH_MEM_LOWER_BOUND + 0xCC0)
#define FH_MEM_RCSR_CHNL0 (FH_MEM_RCSR_LOWER_BOUND)
#define FH_MEM_RCSR_CHNL0_CONFIG_REG (FH_MEM_RCSR_CHNL0)
/* RSSR Area - Rx shared ctrl & status registers */
#define FH_RCSR_CHNL0_RX_CONFIG_RB_TIMEOUT_MASK (0x00000FF0) /* bit 4-11 */
#define FH_RCSR_CHNL0_RX_CONFIG_IRQ_DEST_MASK (0x00001000) /* bit 12 */
#define FH_RCSR_CHNL0_RX_CONFIG_SINGLE_FRAME_MASK (0x00008000) /* bit 15 */
#define FH_RCSR_CHNL0_RX_CONFIG_RB_SIZE_MASK (0x00030000) /* bits 16-17 */
#define FH_RCSR_CHNL0_RX_CONFIG_RBDBC_SIZE_MASK (0x00F00000) /* bits 20-23 */
#define FH_RCSR_CHNL0_RX_CONFIG_DMA_CHNL_EN_MASK (0xC0000000) /* bits 30-31 */
#define FH_RCSR_RX_CONFIG_RBDCB_SIZE_BITSHIFT (20)
#define FH_RCSR_RX_CONFIG_RB_SIZE_BITSHIFT (16)
#define FH_RCSR_RX_CONFIG_CHNL_EN_PAUSE_VAL (0x00000000)
#define FH_RCSR_RX_CONFIG_CHNL_EN_PAUSE_EOF_VAL (0x40000000)
#define FH_RCSR_RX_CONFIG_CHNL_EN_ENABLE_VAL (0x80000000)
#define IWL_FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_4K (0x00000000)
#define FH_RCSR_CHNL0_RX_CONFIG_IRQ_DEST_NO_INT_VAL (0x00000000)
#define FH_RCSR_CHNL0_RX_CONFIG_IRQ_DEST_INT_HOST_VAL (0x00001000)
/**
* Rx Shared Status Registers (RSSR)
*
* After stopping Rx DMA channel (writing 0 to FH_MEM_RCSR_CHNL0_CONFIG_REG),
* driver must poll FH_MEM_RSSR_RX_STATUS_REG until Rx channel is idle.
*
* Bit fields:
* 24: 1 = Channel 0 is idle
*
* FH_MEM_RSSR_SHARED_CTRL_REG and FH_MEM_RSSR_RX_ENABLE_ERR_IRQ2DRV contain
* default values that should not be altered by the driver.
*/
#define FH_MEM_RSSR_LOWER_BOUND (FH_MEM_LOWER_BOUND + 0xC40)
#define FH_MEM_RSSR_UPPER_BOUND (FH_MEM_LOWER_BOUND + 0xD00)
#define FH_MEM_RSSR_SHARED_CTRL_REG (FH_MEM_RSSR_LOWER_BOUND)
#define FH_MEM_RSSR_RX_STATUS_REG (FH_MEM_RSSR_LOWER_BOUND + 0x004)
#define FH_MEM_RSSR_RX_ENABLE_ERR_IRQ2DRV (FH_MEM_RSSR_LOWER_BOUND + 0x008)
#define FH_RSSR_CHNL0_RX_STATUS_CHNL_IDLE (0x01000000)
/* TCSR */
#define IWL_FH_TCSR_LOWER_BOUND (FH_MEM_LOWER_BOUND + 0xD00)
#define IWL_FH_TCSR_UPPER_BOUND (FH_MEM_LOWER_BOUND + 0xE60)
......@@ -1369,17 +1527,6 @@ enum {
#define IWL_FH_TCSR_TX_CONFIG_REG_VAL_DMA_CHNL_ENABLE (0x80000000)
/* RCSR: channel 0 rx_config register defines */
#define FH_RCSR_RX_CONFIG_RBDCB_SIZE_BITSHIFT (20)
#define FH_RCSR_RX_CONFIG_CHNL_EN_ENABLE_VAL (0x80000000)
#define IWL_FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_4K (0x00000000)
/* RCSR channel 0 config register values */
#define FH_RCSR_CHNL0_RX_CONFIG_IRQ_DEST_INT_HOST_VAL (0x00001000)
#define SCD_WIN_SIZE 64
#define SCD_FRAME_LIMIT 64
......
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