Merge branch 'samsung/exynos5' into next/soc2
[linux-2.6.git] / arch / arm / mach-tegra / dma.c
index e945ae2..abea4f6 100644 (file)
@@ -33,6 +33,8 @@
 #include <mach/iomap.h>
 #include <mach/suspend.h>
 
+#include "apbio.h"
+
 #define APB_DMA_GEN                            0x000
 #define GEN_ENABLE                             (1<<31)
 
@@ -50,8 +52,6 @@
 #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 NV_DMA_MAX_TRASFER_SIZE 0x10000
 
-const unsigned int ahb_addr_wrap_table[8] = {
+static 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};
+static 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};
+static const unsigned int bus_width_table[5] = {
+       8, 16, 32, 64, 128
+};
 
 #define TEGRA_DMA_NAME_SIZE 16
 struct tegra_dma_channel {
@@ -129,6 +133,7 @@ struct tegra_dma_channel {
 
 static bool tegra_dma_initialized;
 static DEFINE_MUTEX(tegra_dma_lock);
+static DEFINE_SPINLOCK(enable_lock);
 
 static DECLARE_BITMAP(channel_usage, NV_DMA_MAX_CHANNELS);
 static struct tegra_dma_channel dma_channels[NV_DMA_MAX_CHANNELS];
@@ -157,7 +162,7 @@ void tegra_dma_dequeue(struct tegra_dma_channel *ch)
        return;
 }
 
-void tegra_dma_stop(struct tegra_dma_channel *ch)
+static void tegra_dma_stop(struct tegra_dma_channel *ch)
 {
        u32 csr;
        u32 status;
@@ -174,38 +179,96 @@ void tegra_dma_stop(struct tegra_dma_channel *ch)
                writel(status, ch->addr + APB_DMA_CHAN_STA);
 }
 
-int tegra_dma_cancel(struct tegra_dma_channel *ch)
+static int tegra_dma_cancel(struct tegra_dma_channel *ch)
 {
-       u32 csr;
        unsigned long irq_flags;
 
        spin_lock_irqsave(&ch->lock, irq_flags);
        while (!list_empty(&ch->list))
                list_del(ch->list.next);
 
-       csr = readl(ch->addr + APB_DMA_CHAN_CSR);
-       csr &= ~CSR_REQ_SEL_MASK;
-       csr |= CSR_REQ_SEL_INVALID;
-       writel(csr, ch->addr + APB_DMA_CHAN_CSR);
-
        tegra_dma_stop(ch);
 
        spin_unlock_irqrestore(&ch->lock, irq_flags);
        return 0;
 }
 
+static unsigned int get_channel_status(struct tegra_dma_channel *ch,
+                       struct tegra_dma_req *req, bool is_stop_dma)
+{
+       void __iomem *addr = IO_ADDRESS(TEGRA_APB_DMA_BASE);
+       unsigned int status;
+
+       if (is_stop_dma) {
+               /*
+                * STOP the DMA and get the transfer count.
+                * Getting the transfer count is tricky.
+                *  - Globally disable DMA on all channels
+                *  - Read the channel's status register to know the number
+                *    of pending bytes to be transfered.
+                *  - Stop the dma channel
+                *  - Globally re-enable DMA to resume other transfers
+                */
+               spin_lock(&enable_lock);
+               writel(0, addr + APB_DMA_GEN);
+               udelay(20);
+               status = readl(ch->addr + APB_DMA_CHAN_STA);
+               tegra_dma_stop(ch);
+               writel(GEN_ENABLE, addr + APB_DMA_GEN);
+               spin_unlock(&enable_lock);
+               if (status & STA_ISE_EOC) {
+                       pr_err("Got Dma Int here clearing");
+                       writel(status, ch->addr + APB_DMA_CHAN_STA);
+               }
+               req->status = TEGRA_DMA_REQ_ERROR_ABORTED;
+       } else {
+               status = readl(ch->addr + APB_DMA_CHAN_STA);
+       }
+       return status;
+}
+
+/* should be called with the channel lock held */
+static unsigned int dma_active_count(struct tegra_dma_channel *ch,
+       struct tegra_dma_req *req, unsigned int status)
+{
+       unsigned int to_transfer;
+       unsigned int req_transfer_count;
+       unsigned int bytes_transferred;
+
+       to_transfer = ((status & STA_COUNT_MASK) >> STA_COUNT_SHIFT) + 1;
+       req_transfer_count = ch->req_transfer_count + 1;
+       bytes_transferred = req_transfer_count;
+       if (status & STA_BUSY)
+               bytes_transferred -= to_transfer;
+       /*
+        * In continuous 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.
+        */
+       if (ch->mode & TEGRA_DMA_MODE_CONTINOUS) {
+               if (req->buffer_status == TEGRA_DMA_REQ_BUF_STATUS_HALF_FULL)
+                       bytes_transferred += req_transfer_count;
+               if (status & STA_ISE_EOC)
+                       bytes_transferred += req_transfer_count;
+       }
+       bytes_transferred *= 4;
+       return bytes_transferred;
+}
+
 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;
+       int stop = 0;
 
        spin_lock_irqsave(&ch->lock, irq_flags);
+
+       if (list_entry(ch->list.next, struct tegra_dma_req, node) == _req)
+               stop = 1;
+
        list_for_each_entry(req, &ch->list, node) {
                if (req == _req) {
                        list_del(&req->node);
@@ -218,47 +281,12 @@ int tegra_dma_dequeue_req(struct tegra_dma_channel *ch,
                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 = readl(ch->addr + APB_DMA_CHAN_CSR);
-       csr &= ~CSR_REQ_SEL_MASK;
-       csr |= CSR_REQ_SEL_INVALID;
-       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->req_transfer_count;
-       req_transfer_count += 1;
-       to_transfer += 1;
+       if (!stop)
+               goto skip_stop_dma;
 
-       req->bytes_transferred = req_transfer_count;
+       status = get_channel_status(ch, req, true);
+       req->bytes_transferred = dma_active_count(ch, req, status);
 
-       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;
@@ -266,6 +294,8 @@ int tegra_dma_dequeue_req(struct tegra_dma_channel *ch,
                        typeof(*next_req), node);
                tegra_dma_update_hw(ch, next_req);
        }
+
+skip_stop_dma:
        req->status = -TEGRA_DMA_REQ_ERROR_ABORTED;
 
        spin_unlock_irqrestore(&ch->lock, irq_flags);
@@ -353,7 +383,7 @@ struct tegra_dma_channel *tegra_dma_allocate_channel(int mode)
        int channel;
        struct tegra_dma_channel *ch = NULL;
 
-       if (WARN_ON(!tegra_dma_initialized))
+       if (!tegra_dma_initialized)
                return NULL;
 
        mutex_lock(&tegra_dma_lock);