/*
* Copyright (c) 2004-2008 Reyk Floeter <reyk@openbsd.org>
* Copyright (c) 2006-2008 Nick Kossifidis <mickflemm@gmail.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
/*************************************\
* DMA and interrupt masking functions *
\*************************************/
/*
* dma.c - DMA and interrupt masking functions
*
* Here we setup descriptor pointers (rxdp/txdp) start/stop dma engine and
* handle queue setup for 5210 chipset (rest are handled on qcu.c).
* Also we setup interrupt mask register (IMR) and read the various iterrupt
* status registers (ISR).
*
* TODO: Handle SISR on 5211+ and introduce a function to return the queue
* number that resulted the interrupt.
*/
#include "ath5k.h"
#include "reg.h"
#include "debug.h"
#include "base.h"
/*********\
* Receive *
\*********/
/**
* ath5k_hw_start_rx_dma - Start DMA receive
*
* @ah: The &struct ath5k_hw
*/
void ath5k_hw_start_rx_dma(struct ath5k_hw *ah)
{
ATH5K_TRACE(ah->ah_sc);
ath5k_hw_reg_write(ah, AR5K_CR_RXE, AR5K_CR);
ath5k_hw_reg_read(ah, AR5K_CR);
}
/**
* ath5k_hw_stop_rx_dma - Stop DMA receive
*
* @ah: The &struct ath5k_hw
*/
int ath5k_hw_stop_rx_dma(struct ath5k_hw *ah)
{
unsigned int i;
ATH5K_TRACE(ah->ah_sc);
ath5k_hw_reg_write(ah, AR5K_CR_RXD, AR5K_CR);
/*
* It may take some time to disable the DMA receive unit
*/
for (i = 2000; i > 0 &&
(ath5k_hw_reg_read(ah, AR5K_CR) & AR5K_CR_RXE) != 0;
i--)
udelay(10);
return i ? 0 : -EBUSY;
}
/**
* ath5k_hw_get_rxdp - Get RX Descriptor's address
*
* @ah: The &struct ath5k_hw
*
* XXX: Is RXDP read and clear ?
*/
u32 ath5k_hw_get_rxdp(struct ath5k_hw *ah)
{
return ath5k_hw_reg_read(ah, AR5K_RXDP);
}
/**
* ath5k_hw_set_rxdp - Set RX Descriptor's address
*
* @ah: The &struct ath5k_hw
* @phys_addr: RX descriptor address
*
* XXX: Should we check if rx is enabled before setting rxdp ?
*/
void ath5k_hw_set_rxdp(struct ath5k_hw *ah, u32 phys_addr)
{
ATH5K_TRACE(ah->ah_sc);
ath5k_hw_reg_write(ah, phys_addr, AR5K_RXDP);
}
/**********\
* Transmit *
\**********/
/**
* ath5k_hw_start_tx_dma - Start DMA transmit for a specific queue
*
* @ah: The &struct ath5k_hw
* @queue: The hw queue number
*
* Start DMA transmit for a specific queue and since 5210 doesn't have
* QCU/DCU, set up queue parameters for 5210 here based on queue type (one
* queue for normal data and one queue for beacons). For queue setup
* on newer chips check out qcu.c. Returns -EINVAL if queue number is out
* of range or if queue is already disabled.
*
* NOTE: Must be called after setting up tx control descriptor for that
* queue (see below).
*/
int ath5k_hw_start_tx_dma(struct ath5k_hw *ah, unsigned int queue)
{
u32 tx_queue;
ATH5K_TRACE(ah->ah_sc);
AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
/* Return if queue is declared inactive */
if (ah->ah_txq[queue].tqi_type == AR5K_TX_QUEUE_INACTIVE)
return -EIO;
if (ah->ah_version == AR5K_AR5210) {
tx_queue = ath5k_hw_reg_read(ah, AR5K_CR);
/*
* Set the queue by type on 5210
*/
switch (ah->ah_txq[queue].tqi_type) {
case AR5K_TX_QUEUE_DATA:
tx_queue |= AR5K_CR_TXE0 & ~AR5K_CR_TXD0;
break;
case AR5K_TX_QUEUE_BEACON:
tx_queue |= AR5K_CR_TXE1 & ~AR5K_CR_TXD1;
ath5k_hw_reg_write(ah, AR5K_BCR_TQ1V | AR5K_BCR_BDMAE,
AR5K_BSR);
break;
case AR5K_TX_QUEUE_CAB:
tx_queue |= AR5K_CR_TXE1 & ~AR5K_CR_TXD1;
ath5k_hw_reg_write(ah, AR5K_BCR_TQ1FV | AR5K_BCR_TQ1V |
AR5K_BCR_BDMAE, AR5K_BSR);
break;
default:
return -EINVAL;
}
/* Start queue */
ath5k_hw_reg_write(ah, tx_queue, AR5K_CR);
ath5k_hw_reg_read(ah, AR5K_CR);
} else {
/* Return if queue is disabled */
if (AR5K_REG_READ_Q(ah, AR5K_QCU_TXD, queue))
return -EIO;
/* Start queue */
AR5K_REG_WRITE_Q(ah, AR5K_QCU_TXE, queue);
}
return 0;
}
/**
* ath5k_hw_stop_tx_dma - Stop DMA transmit on a specific queue
*
* @ah: The &struct ath5k_hw
* @queue: The hw queue number
*
* Stop DMA transmit on a specific hw queue and drain queue so we don't
* have any pending frames. Returns -EBUSY if we still have pending frames,
* -EINVAL if queue number is out of range.
*
* TODO: Test queue drain code
*/
int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
{
unsigned int i = 100;
u32 tx_queue, pending;
ATH5K_TRACE(ah->ah_sc);
AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
/* Return if queue is declared inactive */
if (ah->ah_txq[queue].tqi_type == AR5K_TX_QUEUE_INACTIVE)
return -EIO;
if (ah->ah_version == AR5K_AR5210) {
tx_queue = ath5k_hw_reg_read(ah, AR5K_CR);
/*
* Set by queue type
*/
switch (ah->ah_txq[queue].tqi_type) {
case AR5K_TX_QUEUE_DATA:
tx_queue |= AR5K_CR_TXD0 & ~AR5K_CR_TXE0;
break;
case AR5K_TX_QUEUE_BEACON:
case AR5K_TX_QUEUE_CAB:
/* XXX Fix me... */
tx_queue |= AR5K_CR_TXD1 & ~AR5K_CR_TXD1;
ath5k_hw_reg_write(ah, 0, AR5K_BSR);
break;
default:
return -EINVAL;
}
/* Stop queue */
ath5k_hw_reg_write(ah, tx_queue, AR5K_CR);
ath5k_hw_reg_read(ah, AR5K_CR);
} else {
/*
* Schedule TX disable and wait until queue is empty
*/
AR5K_REG_WRITE_Q(ah, AR5K_QCU_TXD, queue);
/*Check for pending frames*/
do {
pending = ath5k_hw_reg_read(ah,
AR5K_QUEUE_STATUS(queue)) &
AR5K_QCU_STS_FRMPENDCNT;
udelay(100);
} while (--i && pending);
/* Clear register */
ath5k_hw_reg_write(ah, 0, AR5K_QCU_TXD);
if (pending)
return -EBUSY;
}
/* TODO: Check for success else return error */
return 0;
}
/**
* ath5k_hw_get_txdp - Get TX Descriptor's address for a specific queue
*
* @ah: The &struct ath5k_hw
* @queue: The hw queue number
*
* Get TX descriptor's address for a specific queue. For 5210 we ignore
* the queue number and use tx queue type since we only have 2 queues.
* We use TXDP0 for normal data queue and TXDP1 for beacon queue.
* For newer chips with QCU/DCU we just read the corresponding TXDP register.
*
* XXX: Is TXDP read and clear ?
*/
u32 ath5k_hw_get_txdp(struct ath5k_hw *ah, unsigned int queue)
{
u16 tx_reg;
ATH5K_TRACE(ah->ah_sc);
AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
/*
* Get the transmit queue descriptor pointer from the selected queue
*/
/*5210 doesn't have QCU*/
if (ah->ah_version == AR5K_AR5210) {
switch (ah->ah_txq[queue].tqi_type) {
case AR5K_TX_QUEUE_DATA:
tx_reg = AR5K_NOQCU_TXDP0;
break;
case AR5K_TX_QUEUE_BEACON:
case AR5K_TX_QUEUE_CAB:
tx_reg = AR5K_NOQCU_TXDP1;
break;
default:
return 0xffffffff;
}
} else {
tx_reg = AR5K_QUEUE_TXDP(queue);
}
return ath5k_hw_reg_read(ah, tx_reg);
}
/**
* ath5k_hw_set_txdp - Set TX Descriptor's address for a specific queue
*
* @ah: The &struct ath5k_hw
* @queue: The hw queue number
*
* Set TX descriptor's address for a specific queue. For 5210 we ignore
* the queue number and we use tx queue type since we only have 2 queues
* so as above we use TXDP0 for normal data queue and TXDP1 for beacon queue.
* For newer chips with QCU/DCU we just set the corresponding TXDP register.
* Returns -EINVAL if queue type is invalid for 5210 and -EIO if queue is still
* active.
*/
int ath5k_hw_set_txdp(struct ath5k_hw *ah, unsigned int queue, u32 phys_addr)
{
u16 tx_reg;
ATH5K_TRACE(ah->ah_sc);
AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
/*
* Set the transmit queue descriptor pointer register by type
* on 5210
*/
if (ah->ah_version == AR5K_AR5210) {
switch (ah->ah_txq[queue].tqi_type) {
case AR5K_TX_QUEUE_DATA:
tx_reg = AR5K_NOQCU_TXDP0;
break;
case AR5K_TX_QUEUE_BEACON:
case AR5K_TX_QUEUE_CAB:
tx_reg = AR5K_NOQCU_TXDP1;
break;
default:
return -EINVAL;
}
} else {
/*
* Set the transmit queue descriptor pointer for
* the selected queue on QCU for 5211+
* (this won't work if the queue is still active)
*/
if (AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue))
return -EIO;
tx_reg = AR5K_QUEUE_TXDP(queue);
}
/* Set descriptor pointer */
ath5k_hw_reg_write(ah, phys_addr, tx_reg);
return 0;
}
/**
* ath5k_hw_update_tx_triglevel - Update tx trigger level
*
* @ah: The &struct ath5k_hw
* @increase: Flag to force increase of trigger level
*
* This function increases/decreases the tx trigger level for the tx fifo
* buffer (aka FIFO threshold) that is used to indicate when PCU flushes
* the buffer and transmits it's data. Lowering this results sending small
* frames more quickly but can lead to tx underruns, raising it a lot can
* result other problems (i think bmiss is related). Right now we start with
* the lowest possible (64Bytes) and if we get tx underrun we increase it using
* the increase flag. Returns -EIO if we have have reached maximum/minimum.
*
* XXX: Link this with tx DMA size ?
* XXX: Use it to save interrupts ?
* TODO: Needs testing, i think it's related to bmiss...
*/
int ath5k_hw_update_tx_triglevel(struct ath5k_hw *ah, bool increase)
{
u32 trigger_level, imr;
int ret = -EIO;
ATH5K_TRACE(ah->ah_sc);
/*
* Disable interrupts by setting the mask
*/
imr = ath5k_hw_set_imr(ah, ah->ah_imr & ~AR5K_INT_GLOBAL);
trigger_level = AR5K_REG_MS(ath5k_hw_reg_read(ah, AR5K_TXCFG),
AR5K_TXCFG_TXFULL);
if (!increase) {
if (--trigger_level < AR5K_TUNE_MIN_TX_FIFO_THRES)
goto done;
} else
trigger_level +=
((AR5K_TUNE_MAX_TX_FIFO_THRES - trigger_level) / 2);
/*
* Update trigger level on success
*/
if (ah->ah_version == AR5K_AR5210)
ath5k_hw_reg_write(ah, trigger_level, AR5K_TRIG_LVL);
else
AR5K_REG_WRITE_BITS(ah, AR5K_TXCFG,
AR5K_TXCFG_TXFULL, trigger_level);
ret = 0;
done:
/*
* Restore interrupt mask
*/
ath5k_hw_set_imr(ah, imr);
return ret;
}
/*******************\
* Interrupt masking *
\*******************/
/**
* ath5k_hw_is_intr_pending - Check if we have pending interrupts
*
* @ah: The &struct ath5k_hw
*
* Check if we have pending interrupts to process. Returns 1 if we
* have pending interrupts and 0 if we haven't.
*/
bool ath5k_hw_is_intr_pending(struct ath5k_hw *ah)
{
ATH5K_TRACE(ah->ah_sc);
return ath5k_hw_reg_read(ah, AR5K_INTPEND);
}
/**
* ath5k_hw_get_isr - Get interrupt status
*
* @ah: The @struct ath5k_hw
* @interrupt_mask: Driver's interrupt mask used to filter out
* interrupts in sw.
*
* This function is used inside our interrupt handler to determine the reason
* for the interrupt by reading Primary Interrupt Status Register. Returns an
* abstract interrupt status mask which is mostly ISR with some uncommon bits
* being mapped on some standard non hw-specific positions
* (check out &ath5k_int).
*
* NOTE: We use read-and-clear register, so after this function is called ISR
* is zeroed.
*
* XXX: Why filter interrupts in sw with interrupt_mask ? No benefit at all
* plus it can be misleading (one might thing that we save interrupts this way)
*/
int ath5k_hw_get_isr(struct ath5k_hw *ah, enum ath5k_int *interrupt_mask)
{
u32 data;
ATH5K_TRACE(ah->ah_sc);
/*
* Read interrupt status from the Interrupt Status register
* on 5210
*/
if (ah->ah_version == AR5K_AR5210) {
data = ath5k_hw_reg_read(ah, AR5K_ISR);
if (unlikely(data == AR5K_INT_NOCARD)) {
*interrupt_mask = data;
return -ENODEV;
}
} else {
/*
* Read interrupt status from the Read-And-Clear
* shadow register.
* Note: PISR/SISR Not available on 5210
*/
data = ath5k_hw_reg_read(ah, AR5K_RAC_PISR);
}
/*
* Get abstract interrupt mask (driver-compatible)
*/
*interrupt_mask = (data & AR5K_INT_COMMON) & ah->ah_imr;
if (unlikely(data == AR5K_INT_NOCARD))
return -ENODEV;
if (data & (AR5K_ISR_RXOK | AR5K_ISR_RXERR))
*interrupt_mask |= AR5K_INT_RX;
if (data & (AR5K_ISR_TXOK | AR5K_ISR_TXERR
| AR5K_ISR_TXDESC | AR5K_ISR_TXEOL))
*interrupt_mask |= AR5K_INT_TX;
if (ah->ah_version != AR5K_AR5210) {
/*HIU = Host Interface Unit (PCI etc)*/
if (unlikely(data & (AR5K_ISR_HIUERR)))
*interrupt_mask |= AR5K_INT_FATAL;
/*Beacon Not Ready*/
if (unlikely(data & (AR5K_ISR_BNR)))
*interrupt_mask |= AR5K_INT_BNR;
}
/*
* XXX: BMISS interrupts may occur after association.
* I found this on 5210 code but it needs testing. If this is
* true we should disable them before assoc and re-enable them
* after a successfull assoc + some jiffies.
*/
#if 0
interrupt_mask &= ~AR5K_INT_BMISS;
#endif
/*
* In case we didn't handle anything,
* print the register value.
*/
if (unlikely(*interrupt_mask == 0 && net_ratelimit()))
ATH5K_PRINTF("0x%08x\n", data);
return 0;
}
/**
* ath5k_hw_set_imr - Set interrupt mask
*
* @ah: The &struct ath5k_hw
* @new_mask: The new interrupt mask to be set
*
* Set the interrupt mask in hw to save interrupts. We do that by mapping
* ath5k_int bits to hw-specific bits to remove abstraction and writing
* Interrupt Mask Register.
*/
enum ath5k_int ath5k_hw_set_imr(struct ath5k_hw *ah, enum ath5k_int new_mask)
{
enum ath5k_int old_mask, int_mask;
/*
* Disable card interrupts to prevent any race conditions
* (they will be re-enabled afterwards).
*/
ath5k_hw_reg_write(ah, AR5K_IER_DISABLE, AR5K_IER);
ath5k_hw_reg_read(ah, AR5K_IER);
old_mask = ah->ah_imr;
/*
* Add additional, chipset-dependent interrupt mask flags
* and write them to the IMR (interrupt mask register).
*/
int_mask = new_mask & AR5K_INT_COMMON;
if (new_mask & AR5K_INT_RX)
int_mask |= AR5K_IMR_RXOK | AR5K_IMR_RXERR | AR5K_IMR_RXORN |
AR5K_IMR_RXDESC;
if (new_mask & AR5K_INT_TX)
int_mask |= AR5K_IMR_TXOK | AR5K_IMR_TXERR | AR5K_IMR_TXDESC |
AR5K_IMR_TXURN;
if (ah->ah_version != AR5K_AR5210) {
if (new_mask & AR5K_INT_FATAL) {
int_mask |= AR5K_IMR_HIUERR;
AR5K_REG_ENABLE_BITS(ah, AR5K_SIMR2, AR5K_SIMR2_MCABT |
AR5K_SIMR2_SSERR | AR5K_SIMR2_DPERR);
}
}
ath5k_hw_reg_write(ah, int_mask, AR5K_PIMR);
/* Store new interrupt mask */
ah->ah_imr = new_mask;
/* ..re-enable interrupts */
ath5k_hw_reg_write(ah, AR5K_IER_ENABLE, AR5K_IER);
ath5k_hw_reg_read(ah, AR5K_IER);
return old_mask;
}
