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;
+}
+