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path: root/drivers/net/wireless/ath/ath5k/dma.c
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Diffstat (limited to 'drivers/net/wireless/ath/ath5k/dma.c')
-rw-r--r--drivers/net/wireless/ath/ath5k/dma.c928
1 files changed, 928 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ath5k/dma.c b/drivers/net/wireless/ath/ath5k/dma.c
new file mode 100644
index 0000000..e6c52f7
--- /dev/null
+++ b/drivers/net/wireless/ath/ath5k/dma.c
@@ -0,0 +1,928 @@
+/*
+ * 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 *
+\*************************************/
+
+/**
+ * DOC: 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 interrupt
+ * status registers (ISR).
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include "ath5k.h"
+#include "reg.h"
+#include "debug.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_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
+ */
+static int
+ath5k_hw_stop_rx_dma(struct ath5k_hw *ah)
+{
+ unsigned int i;
+
+ ath5k_hw_reg_write(ah, AR5K_CR_RXD, AR5K_CR);
+
+ /*
+ * It may take some time to disable the DMA receive unit
+ */
+ for (i = 1000; i > 0 &&
+ (ath5k_hw_reg_read(ah, AR5K_CR) & AR5K_CR_RXE) != 0;
+ i--)
+ udelay(100);
+
+ if (!i)
+ ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
+ "failed to stop RX DMA !\n");
+
+ return i ? 0 : -EBUSY;
+}
+
+/**
+ * ath5k_hw_get_rxdp() - Get RX Descriptor's address
+ * @ah: The &struct ath5k_hw
+ */
+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
+ *
+ * Returns -EIO if rx is active
+ */
+int
+ath5k_hw_set_rxdp(struct ath5k_hw *ah, u32 phys_addr)
+{
+ if (ath5k_hw_reg_read(ah, AR5K_CR) & AR5K_CR_RXE) {
+ ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
+ "tried to set RXDP while rx was active !\n");
+ return -EIO;
+ }
+
+ ath5k_hw_reg_write(ah, phys_addr, AR5K_RXDP);
+ return 0;
+}
+
+
+/**********\
+* 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;
+
+ 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 -EINVAL;
+
+ 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 or inactive.
+ */
+static int
+ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
+{
+ unsigned int i = 40;
+ u32 tx_queue, pending;
+
+ 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 -EINVAL;
+
+ 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 {
+
+ /*
+ * Enable DCU early termination to quickly
+ * flush any pending frames from QCU
+ */
+ AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
+ AR5K_QCU_MISC_DCU_EARLY);
+
+ /*
+ * Schedule TX disable and wait until queue is empty
+ */
+ AR5K_REG_WRITE_Q(ah, AR5K_QCU_TXD, queue);
+
+ /* Wait for queue to stop */
+ for (i = 1000; i > 0 &&
+ (AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue) != 0);
+ i--)
+ udelay(100);
+
+ if (AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue))
+ ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
+ "queue %i didn't stop !\n", queue);
+
+ /* Check for pending frames */
+ i = 1000;
+ do {
+ pending = ath5k_hw_reg_read(ah,
+ AR5K_QUEUE_STATUS(queue)) &
+ AR5K_QCU_STS_FRMPENDCNT;
+ udelay(100);
+ } while (--i && pending);
+
+ /* For 2413+ order PCU to drop packets using
+ * QUIET mechanism */
+ if (ah->ah_mac_version >= (AR5K_SREV_AR2414 >> 4) &&
+ pending) {
+ /* Set periodicity and duration */
+ ath5k_hw_reg_write(ah,
+ AR5K_REG_SM(100, AR5K_QUIET_CTL2_QT_PER)|
+ AR5K_REG_SM(10, AR5K_QUIET_CTL2_QT_DUR),
+ AR5K_QUIET_CTL2);
+
+ /* Enable quiet period for current TSF */
+ ath5k_hw_reg_write(ah,
+ AR5K_QUIET_CTL1_QT_EN |
+ AR5K_REG_SM(ath5k_hw_reg_read(ah,
+ AR5K_TSF_L32_5211) >> 10,
+ AR5K_QUIET_CTL1_NEXT_QT_TSF),
+ AR5K_QUIET_CTL1);
+
+ /* Force channel idle high */
+ AR5K_REG_ENABLE_BITS(ah, AR5K_DIAG_SW_5211,
+ AR5K_DIAG_SW_CHANNEL_IDLE_HIGH);
+
+ /* Wait a while and disable mechanism */
+ udelay(400);
+ AR5K_REG_DISABLE_BITS(ah, AR5K_QUIET_CTL1,
+ AR5K_QUIET_CTL1_QT_EN);
+
+ /* Re-check for pending frames */
+ i = 100;
+ do {
+ pending = ath5k_hw_reg_read(ah,
+ AR5K_QUEUE_STATUS(queue)) &
+ AR5K_QCU_STS_FRMPENDCNT;
+ udelay(100);
+ } while (--i && pending);
+
+ AR5K_REG_DISABLE_BITS(ah, AR5K_DIAG_SW_5211,
+ AR5K_DIAG_SW_CHANNEL_IDLE_HIGH);
+
+ if (pending)
+ ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
+ "quiet mechanism didn't work q:%i !\n",
+ queue);
+ }
+
+ /*
+ * Disable DCU early termination
+ */
+ AR5K_REG_DISABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
+ AR5K_QCU_MISC_DCU_EARLY);
+
+ /* Clear register */
+ ath5k_hw_reg_write(ah, 0, AR5K_QCU_TXD);
+ if (pending) {
+ ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
+ "tx dma didn't stop (q:%i, frm:%i) !\n",
+ queue, pending);
+ return -EBUSY;
+ }
+ }
+
+ /* TODO: Check for success on 5210 else return error */
+ return 0;
+}
+
+/**
+ * ath5k_hw_stop_beacon_queue() - Stop beacon queue
+ * @ah: The &struct ath5k_hw
+ * @queue: The queue number
+ *
+ * Returns -EIO if queue didn't stop
+ */
+int
+ath5k_hw_stop_beacon_queue(struct ath5k_hw *ah, unsigned int queue)
+{
+ int ret;
+ ret = ath5k_hw_stop_tx_dma(ah, queue);
+ if (ret) {
+ ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
+ "beacon queue didn't stop !\n");
+ return -EIO;
+ }
+ 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;
+
+ 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
+ * @phys_addr: The physical address
+ *
+ * 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;
+
+ 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 its data. Lowering this results sending small
+ * frames more quickly but can lead to tx underruns, raising it a lot can
+ * result other problems. 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 reached maximum/minimum.
+ *
+ * XXX: Link this with tx DMA size ?
+ * XXX2: Use it to save interrupts ?
+ */
+int
+ath5k_hw_update_tx_triglevel(struct ath5k_hw *ah, bool increase)
+{
+ u32 trigger_level, imr;
+ int ret = -EIO;
+
+ /*
+ * 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)
+{
+ return ath5k_hw_reg_read(ah, AR5K_INTPEND) == 1 ? 1 : 0;
+}
+
+/**
+ * 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 do write-to-clear, so the active PISR/SISR bits at the time this
+ * function gets called are cleared on return.
+ */
+int
+ath5k_hw_get_isr(struct ath5k_hw *ah, enum ath5k_int *interrupt_mask)
+{
+ u32 data = 0;
+
+ /*
+ * Read interrupt status from Primary Interrupt
+ * Register.
+ *
+ * Note: PISR/SISR Not available on 5210
+ */
+ if (ah->ah_version == AR5K_AR5210) {
+ u32 isr = 0;
+ isr = ath5k_hw_reg_read(ah, AR5K_ISR);
+ if (unlikely(isr == AR5K_INT_NOCARD)) {
+ *interrupt_mask = isr;
+ return -ENODEV;
+ }
+
+ /*
+ * Filter out the non-common bits from the interrupt
+ * status.
+ */
+ *interrupt_mask = (isr & AR5K_INT_COMMON) & ah->ah_imr;
+
+ /* Hanlde INT_FATAL */
+ if (unlikely(isr & (AR5K_ISR_SSERR | AR5K_ISR_MCABT
+ | AR5K_ISR_DPERR)))
+ *interrupt_mask |= AR5K_INT_FATAL;
+
+ /*
+ * 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 successful assoc + some jiffies.
+ interrupt_mask &= ~AR5K_INT_BMISS;
+ */
+
+ data = isr;
+ } else {
+ u32 pisr = 0;
+ u32 pisr_clear = 0;
+ u32 sisr0 = 0;
+ u32 sisr1 = 0;
+ u32 sisr2 = 0;
+ u32 sisr3 = 0;
+ u32 sisr4 = 0;
+
+ /* Read PISR and SISRs... */
+ pisr = ath5k_hw_reg_read(ah, AR5K_PISR);
+ if (unlikely(pisr == AR5K_INT_NOCARD)) {
+ *interrupt_mask = pisr;
+ return -ENODEV;
+ }
+
+ sisr0 = ath5k_hw_reg_read(ah, AR5K_SISR0);
+ sisr1 = ath5k_hw_reg_read(ah, AR5K_SISR1);
+ sisr2 = ath5k_hw_reg_read(ah, AR5K_SISR2);
+ sisr3 = ath5k_hw_reg_read(ah, AR5K_SISR3);
+ sisr4 = ath5k_hw_reg_read(ah, AR5K_SISR4);
+
+ /*
+ * PISR holds the logical OR of interrupt bits
+ * from SISR registers:
+ *
+ * TXOK and TXDESC -> Logical OR of TXOK and TXDESC
+ * per-queue bits on SISR0
+ *
+ * TXERR and TXEOL -> Logical OR of TXERR and TXEOL
+ * per-queue bits on SISR1
+ *
+ * TXURN -> Logical OR of TXURN per-queue bits on SISR2
+ *
+ * HIUERR -> Logical OR of MCABT, SSERR and DPER bits on SISR2
+ *
+ * BCNMISC -> Logical OR of TIM, CAB_END, DTIM_SYNC
+ * BCN_TIMEOUT, CAB_TIMEOUT and DTIM
+ * (and TSFOOR ?) bits on SISR2
+ *
+ * QCBRORN and QCBRURN -> Logical OR of QCBRORN and
+ * QCBRURN per-queue bits on SISR3
+ * QTRIG -> Logical OR of QTRIG per-queue bits on SISR4
+ *
+ * If we clean these bits on PISR we 'll also clear all
+ * related bits from SISRs, e.g. if we write the TXOK bit on
+ * PISR we 'll clean all TXOK bits from SISR0 so if a new TXOK
+ * interrupt got fired for another queue while we were reading
+ * the interrupt registers and we write back the TXOK bit on
+ * PISR we 'll lose it. So make sure that we don't write back
+ * on PISR any bits that come from SISRs. Clearing them from
+ * SISRs will also clear PISR so no need to worry here.
+ */
+
+ /* XXX: There seems to be an issue on some cards
+ * with tx interrupt flags not being updated
+ * on PISR despite that all Tx interrupt bits
+ * are cleared on SISRs. Since we handle all
+ * Tx queues all together it shouldn't be an
+ * issue if we clear Tx interrupt flags also
+ * on PISR to avoid that.
+ */
+ pisr_clear = (pisr & ~AR5K_ISR_BITS_FROM_SISRS) |
+ (pisr & AR5K_INT_TX_ALL);
+
+ /*
+ * Write to clear them...
+ * Note: This means that each bit we write back
+ * to the registers will get cleared, leaving the
+ * rest unaffected. So this won't affect new interrupts
+ * we didn't catch while reading/processing, we 'll get
+ * them next time get_isr gets called.
+ */
+ ath5k_hw_reg_write(ah, sisr0, AR5K_SISR0);
+ ath5k_hw_reg_write(ah, sisr1, AR5K_SISR1);
+ ath5k_hw_reg_write(ah, sisr2, AR5K_SISR2);
+ ath5k_hw_reg_write(ah, sisr3, AR5K_SISR3);
+ ath5k_hw_reg_write(ah, sisr4, AR5K_SISR4);
+ ath5k_hw_reg_write(ah, pisr_clear, AR5K_PISR);
+ /* Flush previous write */
+ ath5k_hw_reg_read(ah, AR5K_PISR);
+
+ /*
+ * Filter out the non-common bits from the interrupt
+ * status.
+ */
+ *interrupt_mask = (pisr & AR5K_INT_COMMON) & ah->ah_imr;
+
+
+ /* We treat TXOK,TXDESC, TXERR and TXEOL
+ * the same way (schedule the tx tasklet)
+ * so we track them all together per queue */
+ if (pisr & AR5K_ISR_TXOK)
+ ah->ah_txq_isr_txok_all |= AR5K_REG_MS(sisr0,
+ AR5K_SISR0_QCU_TXOK);
+
+ if (pisr & AR5K_ISR_TXDESC)
+ ah->ah_txq_isr_txok_all |= AR5K_REG_MS(sisr0,
+ AR5K_SISR0_QCU_TXDESC);
+
+ if (pisr & AR5K_ISR_TXERR)
+ ah->ah_txq_isr_txok_all |= AR5K_REG_MS(sisr1,
+ AR5K_SISR1_QCU_TXERR);
+
+ if (pisr & AR5K_ISR_TXEOL)
+ ah->ah_txq_isr_txok_all |= AR5K_REG_MS(sisr1,
+ AR5K_SISR1_QCU_TXEOL);
+
+ /* Currently this is not much useful since we treat
+ * all queues the same way if we get a TXURN (update
+ * tx trigger level) but we might need it later on*/
+ if (pisr & AR5K_ISR_TXURN)
+ ah->ah_txq_isr_txurn |= AR5K_REG_MS(sisr2,
+ AR5K_SISR2_QCU_TXURN);
+
+ /* Misc Beacon related interrupts */
+
+ /* For AR5211 */
+ if (pisr & AR5K_ISR_TIM)
+ *interrupt_mask |= AR5K_INT_TIM;
+
+ /* For AR5212+ */
+ if (pisr & AR5K_ISR_BCNMISC) {
+ if (sisr2 & AR5K_SISR2_TIM)
+ *interrupt_mask |= AR5K_INT_TIM;
+ if (sisr2 & AR5K_SISR2_DTIM)
+ *interrupt_mask |= AR5K_INT_DTIM;
+ if (sisr2 & AR5K_SISR2_DTIM_SYNC)
+ *interrupt_mask |= AR5K_INT_DTIM_SYNC;
+ if (sisr2 & AR5K_SISR2_BCN_TIMEOUT)
+ *interrupt_mask |= AR5K_INT_BCN_TIMEOUT;
+ if (sisr2 & AR5K_SISR2_CAB_TIMEOUT)
+ *interrupt_mask |= AR5K_INT_CAB_TIMEOUT;
+ }
+
+ /* Below interrupts are unlikely to happen */
+
+ /* HIU = Host Interface Unit (PCI etc)
+ * Can be one of MCABT, SSERR, DPERR from SISR2 */
+ if (unlikely(pisr & (AR5K_ISR_HIUERR)))
+ *interrupt_mask |= AR5K_INT_FATAL;
+
+ /*Beacon Not Ready*/
+ if (unlikely(pisr & (AR5K_ISR_BNR)))
+ *interrupt_mask |= AR5K_INT_BNR;
+
+ /* A queue got CBR overrun */
+ if (unlikely(pisr & (AR5K_ISR_QCBRORN))) {
+ *interrupt_mask |= AR5K_INT_QCBRORN;
+ ah->ah_txq_isr_qcborn |= AR5K_REG_MS(sisr3,
+ AR5K_SISR3_QCBRORN);
+ }
+
+ /* A queue got CBR underrun */
+ if (unlikely(pisr & (AR5K_ISR_QCBRURN))) {
+ *interrupt_mask |= AR5K_INT_QCBRURN;
+ ah->ah_txq_isr_qcburn |= AR5K_REG_MS(sisr3,
+ AR5K_SISR3_QCBRURN);
+ }
+
+ /* A queue got triggered */
+ if (unlikely(pisr & (AR5K_ISR_QTRIG))) {
+ *interrupt_mask |= AR5K_INT_QTRIG;
+ ah->ah_txq_isr_qtrig |= AR5K_REG_MS(sisr4,
+ AR5K_SISR4_QTRIG);
+ }
+
+ data = pisr;
+ }
+
+ /*
+ * In case we didn't handle anything,
+ * print the register value.
+ */
+ if (unlikely(*interrupt_mask == 0 && net_ratelimit()))
+ ATH5K_PRINTF("ISR: 0x%08x IMR: 0x%08x\n", data, ah->ah_imr);
+
+ 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;
+
+ old_mask = ah->ah_imr;
+
+ /*
+ * Disable card interrupts to prevent any race conditions
+ * (they will be re-enabled afterwards if AR5K_INT GLOBAL
+ * is set again on the new mask).
+ */
+ if (old_mask & AR5K_INT_GLOBAL) {
+ ath5k_hw_reg_write(ah, AR5K_IER_DISABLE, AR5K_IER);
+ ath5k_hw_reg_read(ah, AR5K_IER);
+ }
+
+ /*
+ * Add additional, chipset-dependent interrupt mask flags
+ * and write them to the IMR (interrupt mask register).
+ */
+ int_mask = new_mask & AR5K_INT_COMMON;
+
+ if (ah->ah_version != AR5K_AR5210) {
+ /* Preserve per queue TXURN interrupt mask */
+ u32 simr2 = ath5k_hw_reg_read(ah, AR5K_SIMR2)
+ & AR5K_SIMR2_QCU_TXURN;
+
+ /* Fatal interrupt abstraction for 5211+ */
+ if (new_mask & AR5K_INT_FATAL) {
+ int_mask |= AR5K_IMR_HIUERR;
+ simr2 |= (AR5K_SIMR2_MCABT | AR5K_SIMR2_SSERR
+ | AR5K_SIMR2_DPERR);
+ }
+
+ /* Misc beacon related interrupts */
+ if (new_mask & AR5K_INT_TIM)
+ int_mask |= AR5K_IMR_TIM;
+
+ if (new_mask & AR5K_INT_TIM)
+ simr2 |= AR5K_SISR2_TIM;
+ if (new_mask & AR5K_INT_DTIM)
+ simr2 |= AR5K_SISR2_DTIM;
+ if (new_mask & AR5K_INT_DTIM_SYNC)
+ simr2 |= AR5K_SISR2_DTIM_SYNC;
+ if (new_mask & AR5K_INT_BCN_TIMEOUT)
+ simr2 |= AR5K_SISR2_BCN_TIMEOUT;
+ if (new_mask & AR5K_INT_CAB_TIMEOUT)
+ simr2 |= AR5K_SISR2_CAB_TIMEOUT;
+
+ /*Beacon Not Ready*/
+ if (new_mask & AR5K_INT_BNR)
+ int_mask |= AR5K_INT_BNR;
+
+ /* Note: Per queue interrupt masks
+ * are set via ath5k_hw_reset_tx_queue() (qcu.c) */
+ ath5k_hw_reg_write(ah, int_mask, AR5K_PIMR);
+ ath5k_hw_reg_write(ah, simr2, AR5K_SIMR2);
+
+ } else {
+ /* Fatal interrupt abstraction for 5210 */
+ if (new_mask & AR5K_INT_FATAL)
+ int_mask |= (AR5K_IMR_SSERR | AR5K_IMR_MCABT
+ | AR5K_IMR_HIUERR | AR5K_IMR_DPERR);
+
+ /* Only common interrupts left for 5210 (no SIMRs) */
+ ath5k_hw_reg_write(ah, int_mask, AR5K_IMR);
+ }
+
+ /* If RXNOFRM interrupt is masked disable it
+ * by setting AR5K_RXNOFRM to zero */
+ if (!(new_mask & AR5K_INT_RXNOFRM))
+ ath5k_hw_reg_write(ah, 0, AR5K_RXNOFRM);
+
+ /* Store new interrupt mask */
+ ah->ah_imr = new_mask;
+
+ /* ..re-enable interrupts if AR5K_INT_GLOBAL is set */
+ if (new_mask & AR5K_INT_GLOBAL) {
+ ath5k_hw_reg_write(ah, AR5K_IER_ENABLE, AR5K_IER);
+ ath5k_hw_reg_read(ah, AR5K_IER);
+ }
+
+ return old_mask;
+}
+
+
+/********************\
+ Init/Stop functions
+\********************/
+
+/**
+ * ath5k_hw_dma_init() - Initialize DMA unit
+ * @ah: The &struct ath5k_hw
+ *
+ * Set DMA size and pre-enable interrupts
+ * (driver handles tx/rx buffer setup and
+ * dma start/stop)
+ *
+ * XXX: Save/restore RXDP/TXDP registers ?
+ */
+void
+ath5k_hw_dma_init(struct ath5k_hw *ah)
+{
+ /*
+ * Set Rx/Tx DMA Configuration
+ *
+ * Set standard DMA size (128). Note that
+ * a DMA size of 512 causes rx overruns and tx errors
+ * on pci-e cards (tested on 5424 but since rx overruns
+ * also occur on 5416/5418 with madwifi we set 128
+ * for all PCI-E cards to be safe).
+ *
+ * XXX: need to check 5210 for this
+ * TODO: Check out tx trigger level, it's always 64 on dumps but I
+ * guess we can tweak it and see how it goes ;-)
+ */
+ if (ah->ah_version != AR5K_AR5210) {
+ AR5K_REG_WRITE_BITS(ah, AR5K_TXCFG,
+ AR5K_TXCFG_SDMAMR, AR5K_DMASIZE_128B);
+ AR5K_REG_WRITE_BITS(ah, AR5K_RXCFG,
+ AR5K_RXCFG_SDMAMW, AR5K_DMASIZE_128B);
+ }
+
+ /* Pre-enable interrupts on 5211/5212*/
+ if (ah->ah_version != AR5K_AR5210)
+ ath5k_hw_set_imr(ah, ah->ah_imr);
+
+}
+
+/**
+ * ath5k_hw_dma_stop() - stop DMA unit
+ * @ah: The &struct ath5k_hw
+ *
+ * Stop tx/rx DMA and interrupts. Returns
+ * -EBUSY if tx or rx dma failed to stop.
+ *
+ * XXX: Sometimes DMA unit hangs and we have
+ * stuck frames on tx queues, only a reset
+ * can fix that.
+ */
+int
+ath5k_hw_dma_stop(struct ath5k_hw *ah)
+{
+ int i, qmax, err;
+ err = 0;
+
+ /* Disable interrupts */
+ ath5k_hw_set_imr(ah, 0);
+
+ /* Stop rx dma */
+ err = ath5k_hw_stop_rx_dma(ah);
+ if (err)
+ return err;
+
+ /* Clear any pending interrupts
+ * and disable tx dma */
+ if (ah->ah_version != AR5K_AR5210) {
+ ath5k_hw_reg_write(ah, 0xffffffff, AR5K_PISR);
+ qmax = AR5K_NUM_TX_QUEUES;
+ } else {
+ /* PISR/SISR Not available on 5210 */
+ ath5k_hw_reg_read(ah, AR5K_ISR);
+ qmax = AR5K_NUM_TX_QUEUES_NOQCU;
+ }
+
+ for (i = 0; i < qmax; i++) {
+ err = ath5k_hw_stop_tx_dma(ah, i);
+ /* -EINVAL -> queue inactive */
+ if (err && err != -EINVAL)
+ return err;
+ }
+
+ return 0;
+}