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-rw-r--r--arch/arm/mach-tegra/dma.c752
1 files changed, 752 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/dma.c b/arch/arm/mach-tegra/dma.c
new file mode 100644
index 0000000..edda6ec
--- /dev/null
+++ b/arch/arm/mach-tegra/dma.c
@@ -0,0 +1,752 @@
+/*
+ * arch/arm/mach-tegra/dma.c
+ *
+ * System DMA driver for NVIDIA Tegra SoCs
+ *
+ * Copyright (c) 2008-2009, NVIDIA Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/delay.h>
+#include <mach/dma.h>
+#include <mach/irqs.h>
+#include <mach/iomap.h>
+
+#define APB_DMA_GEN 0x000
+#define GEN_ENABLE (1<<31)
+
+#define APB_DMA_CNTRL 0x010
+
+#define APB_DMA_IRQ_MASK 0x01c
+
+#define APB_DMA_IRQ_MASK_SET 0x020
+
+#define APB_DMA_CHAN_CSR 0x000
+#define CSR_ENB (1<<31)
+#define CSR_IE_EOC (1<<30)
+#define CSR_HOLD (1<<29)
+#define CSR_DIR (1<<28)
+#define CSR_ONCE (1<<27)
+#define CSR_FLOW (1<<21)
+#define CSR_REQ_SEL_SHIFT 16
+#define CSR_REQ_SEL_MASK (0x1F<<CSR_REQ_SEL_SHIFT)
+#define CSR_REQ_SEL_INVALID (31<<CSR_REQ_SEL_SHIFT)
+#define CSR_WCOUNT_SHIFT 2
+#define CSR_WCOUNT_MASK 0xFFFC
+
+#define APB_DMA_CHAN_STA 0x004
+#define STA_BUSY (1<<31)
+#define STA_ISE_EOC (1<<30)
+#define STA_HALT (1<<29)
+#define STA_PING_PONG (1<<28)
+#define STA_COUNT_SHIFT 2
+#define STA_COUNT_MASK 0xFFFC
+
+#define APB_DMA_CHAN_AHB_PTR 0x010
+
+#define APB_DMA_CHAN_AHB_SEQ 0x014
+#define AHB_SEQ_INTR_ENB (1<<31)
+#define AHB_SEQ_BUS_WIDTH_SHIFT 28
+#define AHB_SEQ_BUS_WIDTH_MASK (0x7<<AHB_SEQ_BUS_WIDTH_SHIFT)
+#define AHB_SEQ_BUS_WIDTH_8 (0<<AHB_SEQ_BUS_WIDTH_SHIFT)
+#define AHB_SEQ_BUS_WIDTH_16 (1<<AHB_SEQ_BUS_WIDTH_SHIFT)
+#define AHB_SEQ_BUS_WIDTH_32 (2<<AHB_SEQ_BUS_WIDTH_SHIFT)
+#define AHB_SEQ_BUS_WIDTH_64 (3<<AHB_SEQ_BUS_WIDTH_SHIFT)
+#define AHB_SEQ_BUS_WIDTH_128 (4<<AHB_SEQ_BUS_WIDTH_SHIFT)
+#define AHB_SEQ_DATA_SWAP (1<<27)
+#define AHB_SEQ_BURST_MASK (0x7<<24)
+#define AHB_SEQ_BURST_1 (4<<24)
+#define AHB_SEQ_BURST_4 (5<<24)
+#define AHB_SEQ_BURST_8 (6<<24)
+#define AHB_SEQ_DBL_BUF (1<<19)
+#define AHB_SEQ_WRAP_SHIFT 16
+#define AHB_SEQ_WRAP_MASK (0x7<<AHB_SEQ_WRAP_SHIFT)
+
+#define APB_DMA_CHAN_APB_PTR 0x018
+
+#define APB_DMA_CHAN_APB_SEQ 0x01c
+#define APB_SEQ_BUS_WIDTH_SHIFT 28
+#define APB_SEQ_BUS_WIDTH_MASK (0x7<<APB_SEQ_BUS_WIDTH_SHIFT)
+#define APB_SEQ_BUS_WIDTH_8 (0<<APB_SEQ_BUS_WIDTH_SHIFT)
+#define APB_SEQ_BUS_WIDTH_16 (1<<APB_SEQ_BUS_WIDTH_SHIFT)
+#define APB_SEQ_BUS_WIDTH_32 (2<<APB_SEQ_BUS_WIDTH_SHIFT)
+#define APB_SEQ_BUS_WIDTH_64 (3<<APB_SEQ_BUS_WIDTH_SHIFT)
+#define APB_SEQ_BUS_WIDTH_128 (4<<APB_SEQ_BUS_WIDTH_SHIFT)
+#define APB_SEQ_DATA_SWAP (1<<27)
+#define APB_SEQ_WRAP_SHIFT 16
+#define APB_SEQ_WRAP_MASK (0x7<<APB_SEQ_WRAP_SHIFT)
+
+#define TEGRA_SYSTEM_DMA_CH_NR 16
+#define TEGRA_SYSTEM_DMA_AVP_CH_NUM 4
+#define TEGRA_SYSTEM_DMA_CH_MIN 0
+#define TEGRA_SYSTEM_DMA_CH_MAX \
+ (TEGRA_SYSTEM_DMA_CH_NR - TEGRA_SYSTEM_DMA_AVP_CH_NUM - 1)
+
+#define NV_DMA_MAX_TRASFER_SIZE 0x10000
+
+const unsigned int ahb_addr_wrap_table[8] = {
+ 0, 32, 64, 128, 256, 512, 1024, 2048
+};
+
+const unsigned int apb_addr_wrap_table[8] = {0, 1, 2, 4, 8, 16, 32, 64};
+
+const unsigned int bus_width_table[5] = {8, 16, 32, 64, 128};
+
+#define TEGRA_DMA_NAME_SIZE 16
+struct tegra_dma_channel {
+ struct list_head list;
+ int id;
+ spinlock_t lock;
+ char name[TEGRA_DMA_NAME_SIZE];
+ void __iomem *addr;
+ int mode;
+ int irq;
+
+ /* Register shadow */
+ u32 csr;
+ u32 ahb_seq;
+ u32 ahb_ptr;
+ u32 apb_seq;
+ u32 apb_ptr;
+};
+
+#define NV_DMA_MAX_CHANNELS 32
+
+static DECLARE_BITMAP(channel_usage, NV_DMA_MAX_CHANNELS);
+static struct tegra_dma_channel dma_channels[NV_DMA_MAX_CHANNELS];
+
+static void tegra_dma_update_hw(struct tegra_dma_channel *ch,
+ struct tegra_dma_req *req);
+static void tegra_dma_update_hw_partial(struct tegra_dma_channel *ch,
+ struct tegra_dma_req *req);
+static void tegra_dma_init_hw(struct tegra_dma_channel *ch);
+static void tegra_dma_stop(struct tegra_dma_channel *ch);
+
+void tegra_dma_flush(struct tegra_dma_channel *ch)
+{
+}
+EXPORT_SYMBOL(tegra_dma_flush);
+
+void tegra_dma_dequeue(struct tegra_dma_channel *ch)
+{
+ struct tegra_dma_req *req;
+
+ req = list_entry(ch->list.next, typeof(*req), node);
+
+ tegra_dma_dequeue_req(ch, req);
+ return;
+}
+
+void tegra_dma_stop(struct tegra_dma_channel *ch)
+{
+ unsigned int csr;
+ unsigned int status;
+
+ csr = ch->csr;
+ csr &= ~CSR_IE_EOC;
+ writel(csr, ch->addr + APB_DMA_CHAN_CSR);
+
+ csr &= ~CSR_ENB;
+ writel(csr, ch->addr + APB_DMA_CHAN_CSR);
+
+ status = readl(ch->addr + APB_DMA_CHAN_STA);
+ if (status & STA_ISE_EOC)
+ writel(status, ch->addr + APB_DMA_CHAN_STA);
+}
+
+int tegra_dma_cancel(struct tegra_dma_channel *ch)
+{
+ unsigned int csr;
+ unsigned long irq_flags;
+
+ spin_lock_irqsave(&ch->lock, irq_flags);
+ while (!list_empty(&ch->list))
+ list_del(ch->list.next);
+
+ csr = ch->csr;
+ csr &= ~CSR_REQ_SEL_MASK;
+ csr |= CSR_REQ_SEL_INVALID;
+
+ /* Set the enable as that is not shadowed */
+ csr |= CSR_ENB;
+ writel(csr, ch->addr + APB_DMA_CHAN_CSR);
+
+ tegra_dma_stop(ch);
+
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+ return 0;
+}
+
+int tegra_dma_dequeue_req(struct tegra_dma_channel *ch,
+ struct tegra_dma_req *_req)
+{
+ unsigned int csr;
+ unsigned int status;
+ struct tegra_dma_req *req = NULL;
+ int found = 0;
+ unsigned long irq_flags;
+ int to_transfer;
+ int req_transfer_count;
+
+ spin_lock_irqsave(&ch->lock, irq_flags);
+ list_for_each_entry(req, &ch->list, node) {
+ if (req == _req) {
+ list_del(&req->node);
+ found = 1;
+ break;
+ }
+ }
+ if (!found) {
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+ return 0;
+ }
+
+ /* STOP the DMA and get the transfer count.
+ * Getting the transfer count is tricky.
+ * - Change the source selector to invalid to stop the DMA from
+ * FIFO to memory.
+ * - Read the status register to know the number of pending
+ * bytes to be transfered.
+ * - Finally stop or program the DMA to the next buffer in the
+ * list.
+ */
+ csr = ch->csr;
+ csr &= ~CSR_REQ_SEL_MASK;
+ csr |= CSR_REQ_SEL_INVALID;
+
+ /* Set the enable as that is not shadowed */
+ csr |= CSR_ENB;
+ writel(csr, ch->addr + APB_DMA_CHAN_CSR);
+
+ /* Get the transfer count */
+ status = readl(ch->addr + APB_DMA_CHAN_STA);
+ to_transfer = (status & STA_COUNT_MASK) >> STA_COUNT_SHIFT;
+ req_transfer_count = (ch->csr & CSR_WCOUNT_MASK) >> CSR_WCOUNT_SHIFT;
+ req_transfer_count += 1;
+ to_transfer += 1;
+
+ req->bytes_transferred = req_transfer_count;
+
+ if (status & STA_BUSY)
+ req->bytes_transferred -= to_transfer;
+
+ /* In continous transfer mode, DMA only tracks the count of the
+ * half DMA buffer. So, if the DMA already finished half the DMA
+ * then add the half buffer to the completed count.
+ *
+ * FIXME: There can be a race here. What if the req to
+ * dequue happens at the same time as the DMA just moved to
+ * the new buffer and SW didn't yet received the interrupt?
+ */
+ if (ch->mode & TEGRA_DMA_MODE_CONTINOUS)
+ if (req->buffer_status == TEGRA_DMA_REQ_BUF_STATUS_HALF_FULL)
+ req->bytes_transferred += req_transfer_count;
+
+ req->bytes_transferred *= 4;
+
+ tegra_dma_stop(ch);
+ if (!list_empty(&ch->list)) {
+ /* if the list is not empty, queue the next request */
+ struct tegra_dma_req *next_req;
+ next_req = list_entry(ch->list.next,
+ typeof(*next_req), node);
+ tegra_dma_update_hw(ch, next_req);
+ }
+ req->status = -TEGRA_DMA_REQ_ERROR_ABORTED;
+
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+
+ /* Callback should be called without any lock */
+ req->complete(req);
+ return 0;
+}
+EXPORT_SYMBOL(tegra_dma_dequeue_req);
+
+bool tegra_dma_is_empty(struct tegra_dma_channel *ch)
+{
+ unsigned long irq_flags;
+ bool is_empty;
+
+ spin_lock_irqsave(&ch->lock, irq_flags);
+ if (list_empty(&ch->list))
+ is_empty = true;
+ else
+ is_empty = false;
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+ return is_empty;
+}
+EXPORT_SYMBOL(tegra_dma_is_empty);
+
+bool tegra_dma_is_req_inflight(struct tegra_dma_channel *ch,
+ struct tegra_dma_req *_req)
+{
+ unsigned long irq_flags;
+ struct tegra_dma_req *req;
+
+ spin_lock_irqsave(&ch->lock, irq_flags);
+ list_for_each_entry(req, &ch->list, node) {
+ if (req == _req) {
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+ return true;
+ }
+ }
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+ return false;
+}
+EXPORT_SYMBOL(tegra_dma_is_req_inflight);
+
+int tegra_dma_enqueue_req(struct tegra_dma_channel *ch,
+ struct tegra_dma_req *req)
+{
+ unsigned long irq_flags;
+ int start_dma = 0;
+
+ if (req->size > NV_DMA_MAX_TRASFER_SIZE ||
+ req->source_addr & 0x3 || req->dest_addr & 0x3) {
+ pr_err("Invalid DMA request for channel %d\n", ch->id);
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&ch->lock, irq_flags);
+
+ req->bytes_transferred = 0;
+ req->status = 0;
+ req->buffer_status = 0;
+ if (list_empty(&ch->list))
+ start_dma = 1;
+
+ list_add_tail(&req->node, &ch->list);
+
+ if (start_dma)
+ tegra_dma_update_hw(ch, req);
+
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+
+ return 0;
+}
+EXPORT_SYMBOL(tegra_dma_enqueue_req);
+
+struct tegra_dma_channel *tegra_dma_allocate_channel(int mode)
+{
+ int channel;
+ struct tegra_dma_channel *ch;
+
+ /* first channel is the shared channel */
+ if (mode & TEGRA_DMA_SHARED) {
+ channel = TEGRA_SYSTEM_DMA_CH_MIN;
+ } else {
+ channel = find_first_zero_bit(channel_usage,
+ ARRAY_SIZE(dma_channels));
+ if (channel >= ARRAY_SIZE(dma_channels))
+ return NULL;
+ }
+ __set_bit(channel, channel_usage);
+ ch = &dma_channels[channel];
+ ch->mode = mode;
+ return ch;
+}
+EXPORT_SYMBOL(tegra_dma_allocate_channel);
+
+void tegra_dma_free_channel(struct tegra_dma_channel *ch)
+{
+ if (ch->mode & TEGRA_DMA_SHARED)
+ return;
+ tegra_dma_cancel(ch);
+ __clear_bit(ch->id, channel_usage);
+}
+EXPORT_SYMBOL(tegra_dma_free_channel);
+
+static void tegra_dma_update_hw_partial(struct tegra_dma_channel *ch,
+ struct tegra_dma_req *req)
+{
+ if (req->to_memory) {
+ ch->apb_ptr = req->source_addr;
+ ch->ahb_ptr = req->dest_addr;
+ } else {
+ ch->apb_ptr = req->dest_addr;
+ ch->ahb_ptr = req->source_addr;
+ }
+ writel(ch->apb_ptr, ch->addr + APB_DMA_CHAN_APB_PTR);
+ writel(ch->ahb_ptr, ch->addr + APB_DMA_CHAN_AHB_PTR);
+
+ req->status = TEGRA_DMA_REQ_INFLIGHT;
+ return;
+}
+
+static void tegra_dma_update_hw(struct tegra_dma_channel *ch,
+ struct tegra_dma_req *req)
+{
+ int ahb_addr_wrap;
+ int apb_addr_wrap;
+ int ahb_bus_width;
+ int apb_bus_width;
+ int index;
+ unsigned long csr;
+
+
+ ch->csr |= CSR_FLOW;
+ ch->csr &= ~CSR_REQ_SEL_MASK;
+ ch->csr |= req->req_sel << CSR_REQ_SEL_SHIFT;
+ ch->ahb_seq &= ~AHB_SEQ_BURST_MASK;
+ ch->ahb_seq |= AHB_SEQ_BURST_1;
+
+ /* One shot mode is always single buffered,
+ * continuous mode is always double buffered
+ * */
+ if (ch->mode & TEGRA_DMA_MODE_ONESHOT) {
+ ch->csr |= CSR_ONCE;
+ ch->ahb_seq &= ~AHB_SEQ_DBL_BUF;
+ ch->csr &= ~CSR_WCOUNT_MASK;
+ ch->csr |= ((req->size>>2) - 1) << CSR_WCOUNT_SHIFT;
+ } else {
+ ch->csr &= ~CSR_ONCE;
+ ch->ahb_seq |= AHB_SEQ_DBL_BUF;
+
+ /* In double buffered mode, we set the size to half the
+ * requested size and interrupt when half the buffer
+ * is full */
+ ch->csr &= ~CSR_WCOUNT_MASK;
+ ch->csr |= ((req->size>>3) - 1) << CSR_WCOUNT_SHIFT;
+ }
+
+ if (req->to_memory) {
+ ch->csr &= ~CSR_DIR;
+ ch->apb_ptr = req->source_addr;
+ ch->ahb_ptr = req->dest_addr;
+
+ apb_addr_wrap = req->source_wrap;
+ ahb_addr_wrap = req->dest_wrap;
+ apb_bus_width = req->source_bus_width;
+ ahb_bus_width = req->dest_bus_width;
+
+ } else {
+ ch->csr |= CSR_DIR;
+ ch->apb_ptr = req->dest_addr;
+ ch->ahb_ptr = req->source_addr;
+
+ apb_addr_wrap = req->dest_wrap;
+ ahb_addr_wrap = req->source_wrap;
+ apb_bus_width = req->dest_bus_width;
+ ahb_bus_width = req->source_bus_width;
+ }
+
+ apb_addr_wrap >>= 2;
+ ahb_addr_wrap >>= 2;
+
+ /* set address wrap for APB size */
+ index = 0;
+ do {
+ if (apb_addr_wrap_table[index] == apb_addr_wrap)
+ break;
+ index++;
+ } while (index < ARRAY_SIZE(apb_addr_wrap_table));
+ BUG_ON(index == ARRAY_SIZE(apb_addr_wrap_table));
+ ch->apb_seq &= ~APB_SEQ_WRAP_MASK;
+ ch->apb_seq |= index << APB_SEQ_WRAP_SHIFT;
+
+ /* set address wrap for AHB size */
+ index = 0;
+ do {
+ if (ahb_addr_wrap_table[index] == ahb_addr_wrap)
+ break;
+ index++;
+ } while (index < ARRAY_SIZE(ahb_addr_wrap_table));
+ BUG_ON(index == ARRAY_SIZE(ahb_addr_wrap_table));
+ ch->ahb_seq &= ~AHB_SEQ_WRAP_MASK;
+ ch->ahb_seq |= index << AHB_SEQ_WRAP_SHIFT;
+
+ for (index = 0; index < ARRAY_SIZE(bus_width_table); index++) {
+ if (bus_width_table[index] == ahb_bus_width)
+ break;
+ }
+ BUG_ON(index == ARRAY_SIZE(bus_width_table));
+ ch->ahb_seq &= ~AHB_SEQ_BUS_WIDTH_MASK;
+ ch->ahb_seq |= index << AHB_SEQ_BUS_WIDTH_SHIFT;
+
+ for (index = 0; index < ARRAY_SIZE(bus_width_table); index++) {
+ if (bus_width_table[index] == apb_bus_width)
+ break;
+ }
+ BUG_ON(index == ARRAY_SIZE(bus_width_table));
+ ch->apb_seq &= ~APB_SEQ_BUS_WIDTH_MASK;
+ ch->apb_seq |= index << APB_SEQ_BUS_WIDTH_SHIFT;
+
+ ch->csr |= CSR_IE_EOC;
+
+ /* update hw registers with the shadow */
+ writel(ch->csr, ch->addr + APB_DMA_CHAN_CSR);
+ writel(ch->apb_seq, ch->addr + APB_DMA_CHAN_APB_SEQ);
+ writel(ch->apb_ptr, ch->addr + APB_DMA_CHAN_APB_PTR);
+ writel(ch->ahb_seq, ch->addr + APB_DMA_CHAN_AHB_SEQ);
+ writel(ch->ahb_ptr, ch->addr + APB_DMA_CHAN_AHB_PTR);
+
+ csr = ch->csr | CSR_ENB;
+ writel(csr, ch->addr + APB_DMA_CHAN_CSR);
+
+ req->status = TEGRA_DMA_REQ_INFLIGHT;
+}
+
+static void tegra_dma_init_hw(struct tegra_dma_channel *ch)
+{
+ /* One shot with an interrupt to CPU after transfer */
+ ch->csr = CSR_ONCE | CSR_IE_EOC;
+ ch->ahb_seq = AHB_SEQ_BUS_WIDTH_32 | AHB_SEQ_INTR_ENB;
+ ch->apb_seq = APB_SEQ_BUS_WIDTH_32 | 1 << APB_SEQ_WRAP_SHIFT;
+}
+
+static void handle_oneshot_dma(struct tegra_dma_channel *ch)
+{
+ struct tegra_dma_req *req;
+
+ spin_lock(&ch->lock);
+ if (list_empty(&ch->list)) {
+ spin_unlock(&ch->lock);
+ return;
+ }
+
+ req = list_entry(ch->list.next, typeof(*req), node);
+ if (req) {
+ int bytes_transferred;
+
+ bytes_transferred =
+ (ch->csr & CSR_WCOUNT_MASK) >> CSR_WCOUNT_SHIFT;
+ bytes_transferred += 1;
+ bytes_transferred <<= 2;
+
+ list_del(&req->node);
+ req->bytes_transferred = bytes_transferred;
+ req->status = TEGRA_DMA_REQ_SUCCESS;
+
+ spin_unlock(&ch->lock);
+ /* Callback should be called without any lock */
+ pr_debug("%s: transferred %d bytes\n", __func__,
+ req->bytes_transferred);
+ req->complete(req);
+ spin_lock(&ch->lock);
+ }
+
+ if (!list_empty(&ch->list)) {
+ req = list_entry(ch->list.next, typeof(*req), node);
+ /* the complete function we just called may have enqueued
+ another req, in which case dma has already started */
+ if (req->status != TEGRA_DMA_REQ_INFLIGHT)
+ tegra_dma_update_hw(ch, req);
+ }
+ spin_unlock(&ch->lock);
+}
+
+static void handle_continuous_dma(struct tegra_dma_channel *ch)
+{
+ struct tegra_dma_req *req;
+
+ spin_lock(&ch->lock);
+ if (list_empty(&ch->list)) {
+ spin_unlock(&ch->lock);
+ return;
+ }
+
+ req = list_entry(ch->list.next, typeof(*req), node);
+ if (req) {
+ if (req->buffer_status == TEGRA_DMA_REQ_BUF_STATUS_EMPTY) {
+ /* Load the next request into the hardware, if available
+ * */
+ if (!list_is_last(&req->node, &ch->list)) {
+ struct tegra_dma_req *next_req;
+
+ next_req = list_entry(req->node.next,
+ typeof(*next_req), node);
+ tegra_dma_update_hw_partial(ch, next_req);
+ }
+ req->buffer_status = TEGRA_DMA_REQ_BUF_STATUS_HALF_FULL;
+ req->status = TEGRA_DMA_REQ_SUCCESS;
+ /* DMA lock is NOT held when callback is called */
+ spin_unlock(&ch->lock);
+ if (likely(req->threshold))
+ req->threshold(req);
+ return;
+
+ } else if (req->buffer_status ==
+ TEGRA_DMA_REQ_BUF_STATUS_HALF_FULL) {
+ /* Callback when the buffer is completely full (i.e on
+ * the second interrupt */
+ int bytes_transferred;
+
+ bytes_transferred =
+ (ch->csr & CSR_WCOUNT_MASK) >> CSR_WCOUNT_SHIFT;
+ bytes_transferred += 1;
+ bytes_transferred <<= 3;
+
+ req->buffer_status = TEGRA_DMA_REQ_BUF_STATUS_FULL;
+ req->bytes_transferred = bytes_transferred;
+ req->status = TEGRA_DMA_REQ_SUCCESS;
+ list_del(&req->node);
+
+ /* DMA lock is NOT held when callbak is called */
+ spin_unlock(&ch->lock);
+ req->complete(req);
+ return;
+
+ } else {
+ BUG();
+ }
+ }
+ spin_unlock(&ch->lock);
+}
+
+static irqreturn_t dma_isr(int irq, void *data)
+{
+ struct tegra_dma_channel *ch = data;
+ unsigned long status;
+
+ status = readl(ch->addr + APB_DMA_CHAN_STA);
+ if (status & STA_ISE_EOC)
+ writel(status, ch->addr + APB_DMA_CHAN_STA);
+ else {
+ pr_warning("Got a spurious ISR for DMA channel %d\n", ch->id);
+ return IRQ_HANDLED;
+ }
+ return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t dma_thread_fn(int irq, void *data)
+{
+ struct tegra_dma_channel *ch = data;
+
+ if (ch->mode & TEGRA_DMA_MODE_ONESHOT)
+ handle_oneshot_dma(ch);
+ else
+ handle_continuous_dma(ch);
+
+
+ return IRQ_HANDLED;
+}
+
+int __init tegra_dma_init(void)
+{
+ int ret = 0;
+ int i;
+ unsigned int irq;
+ void __iomem *addr;
+
+ addr = IO_ADDRESS(TEGRA_APB_DMA_BASE);
+ writel(GEN_ENABLE, addr + APB_DMA_GEN);
+ writel(0, addr + APB_DMA_CNTRL);
+ writel(0xFFFFFFFFul >> (31 - TEGRA_SYSTEM_DMA_CH_MAX),
+ addr + APB_DMA_IRQ_MASK_SET);
+
+ memset(channel_usage, 0, sizeof(channel_usage));
+ memset(dma_channels, 0, sizeof(dma_channels));
+
+ /* Reserve all the channels we are not supposed to touch */
+ for (i = 0; i < TEGRA_SYSTEM_DMA_CH_MIN; i++)
+ __set_bit(i, channel_usage);
+
+ for (i = TEGRA_SYSTEM_DMA_CH_MIN; i <= TEGRA_SYSTEM_DMA_CH_MAX; i++) {
+ struct tegra_dma_channel *ch = &dma_channels[i];
+
+ __clear_bit(i, channel_usage);
+
+ ch->id = i;
+ snprintf(ch->name, TEGRA_DMA_NAME_SIZE, "dma_channel_%d", i);
+
+ ch->addr = IO_ADDRESS(TEGRA_APB_DMA_CH0_BASE +
+ TEGRA_APB_DMA_CH0_SIZE * i);
+
+ spin_lock_init(&ch->lock);
+ INIT_LIST_HEAD(&ch->list);
+ tegra_dma_init_hw(ch);
+
+ irq = INT_APB_DMA_CH0 + i;
+ ret = request_threaded_irq(irq, dma_isr, dma_thread_fn, 0,
+ dma_channels[i].name, ch);
+ if (ret) {
+ pr_err("Failed to register IRQ %d for DMA %d\n",
+ irq, i);
+ goto fail;
+ }
+ ch->irq = irq;
+ }
+ /* mark the shared channel allocated */
+ __set_bit(TEGRA_SYSTEM_DMA_CH_MIN, channel_usage);
+
+ for (i = TEGRA_SYSTEM_DMA_CH_MAX+1; i < NV_DMA_MAX_CHANNELS; i++)
+ __set_bit(i, channel_usage);
+
+ return ret;
+fail:
+ writel(0, addr + APB_DMA_GEN);
+ for (i = TEGRA_SYSTEM_DMA_CH_MIN; i <= TEGRA_SYSTEM_DMA_CH_MAX; i++) {
+ struct tegra_dma_channel *ch = &dma_channels[i];
+ if (ch->irq)
+ free_irq(ch->irq, ch);
+ }
+ return ret;
+}
+
+#ifdef CONFIG_PM
+static u32 apb_dma[5*TEGRA_SYSTEM_DMA_CH_NR + 3];
+
+void tegra_dma_suspend(void)
+{
+ void __iomem *addr = IO_ADDRESS(TEGRA_APB_DMA_BASE);
+ u32 *ctx = apb_dma;
+ int i;
+
+ *ctx++ = readl(addr + APB_DMA_GEN);
+ *ctx++ = readl(addr + APB_DMA_CNTRL);
+ *ctx++ = readl(addr + APB_DMA_IRQ_MASK);
+
+ for (i = 0; i < TEGRA_SYSTEM_DMA_CH_NR; i++) {
+ addr = IO_ADDRESS(TEGRA_APB_DMA_CH0_BASE +
+ TEGRA_APB_DMA_CH0_SIZE * i);
+
+ *ctx++ = readl(addr + APB_DMA_CHAN_CSR);
+ *ctx++ = readl(addr + APB_DMA_CHAN_AHB_PTR);
+ *ctx++ = readl(addr + APB_DMA_CHAN_AHB_SEQ);
+ *ctx++ = readl(addr + APB_DMA_CHAN_APB_PTR);
+ *ctx++ = readl(addr + APB_DMA_CHAN_APB_SEQ);
+ }
+}
+
+void tegra_dma_resume(void)
+{
+ void __iomem *addr = IO_ADDRESS(TEGRA_APB_DMA_BASE);
+ u32 *ctx = apb_dma;
+ int i;
+
+ writel(*ctx++, addr + APB_DMA_GEN);
+ writel(*ctx++, addr + APB_DMA_CNTRL);
+ writel(*ctx++, addr + APB_DMA_IRQ_MASK);
+
+ for (i = 0; i < TEGRA_SYSTEM_DMA_CH_NR; i++) {
+ addr = IO_ADDRESS(TEGRA_APB_DMA_CH0_BASE +
+ TEGRA_APB_DMA_CH0_SIZE * i);
+
+ writel(*ctx++, addr + APB_DMA_CHAN_CSR);
+ writel(*ctx++, addr + APB_DMA_CHAN_AHB_PTR);
+ writel(*ctx++, addr + APB_DMA_CHAN_AHB_SEQ);
+ writel(*ctx++, addr + APB_DMA_CHAN_APB_PTR);
+ writel(*ctx++, addr + APB_DMA_CHAN_APB_SEQ);
+ }
+}
+
+#endif
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