diff options
Diffstat (limited to 'drivers/net/wireless/ath5k/dma.c')
| -rw-r--r-- | drivers/net/wireless/ath5k/dma.c | 566 |
1 files changed, 566 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath5k/dma.c b/drivers/net/wireless/ath5k/dma.c new file mode 100644 index 00000000000..a28090be960 --- /dev/null +++ b/drivers/net/wireless/ath5k/dma.c @@ -0,0 +1,566 @@ +/* + * 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; +} + |