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Diffstat (limited to 'arch/arm/mach-tegra/apbio.c')
-rw-r--r--arch/arm/mach-tegra/apbio.c194
1 files changed, 187 insertions, 7 deletions
diff --git a/arch/arm/mach-tegra/apbio.c b/arch/arm/mach-tegra/apbio.c
index e75451e..dc0fe38 100644
--- a/arch/arm/mach-tegra/apbio.c
+++ b/arch/arm/mach-tegra/apbio.c
@@ -15,6 +15,9 @@
#include <linux/kernel.h>
#include <linux/io.h>
+#include <mach/iomap.h>
+#include <linux/of.h>
+#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
@@ -22,17 +25,21 @@
#include <linux/mutex.h>
#include <mach/dma.h>
-#include <mach/iomap.h>
#include "apbio.h"
+#if defined(CONFIG_TEGRA_SYSTEM_DMA) || defined(CONFIG_TEGRA20_APB_DMA)
static DEFINE_MUTEX(tegra_apb_dma_lock);
-
-static struct tegra_dma_channel *tegra_apb_dma;
static u32 *tegra_apb_bb;
static dma_addr_t tegra_apb_bb_phys;
static DECLARE_COMPLETION(tegra_apb_wait);
+static u32 tegra_apb_readl_direct(unsigned long offset);
+static void tegra_apb_writel_direct(u32 value, unsigned long offset);
+
+#if defined(CONFIG_TEGRA_SYSTEM_DMA)
+static struct tegra_dma_channel *tegra_apb_dma;
+
bool tegra_apb_init(void)
{
struct tegra_dma_channel *ch;
@@ -72,13 +79,13 @@ static void apb_dma_complete(struct tegra_dma_req *req)
complete(&tegra_apb_wait);
}
-u32 tegra_apb_readl(unsigned long offset)
+static u32 tegra_apb_readl_using_dma(unsigned long offset)
{
struct tegra_dma_req req;
int ret;
if (!tegra_apb_dma && !tegra_apb_init())
- return readl(IO_TO_VIRT(offset));
+ return tegra_apb_readl_direct(offset);
mutex_lock(&tegra_apb_dma_lock);
req.complete = apb_dma_complete;
@@ -108,13 +115,13 @@ u32 tegra_apb_readl(unsigned long offset)
return *((u32 *)tegra_apb_bb);
}
-void tegra_apb_writel(u32 value, unsigned long offset)
+static void tegra_apb_writel_using_dma(u32 value, unsigned long offset)
{
struct tegra_dma_req req;
int ret;
if (!tegra_apb_dma && !tegra_apb_init()) {
- writel(value, IO_TO_VIRT(offset));
+ tegra_apb_writel_direct(value, offset);
return;
}
@@ -143,3 +150,176 @@ void tegra_apb_writel(u32 value, unsigned long offset)
mutex_unlock(&tegra_apb_dma_lock);
}
+
+#else
+static struct dma_chan *tegra_apb_dma_chan;
+static struct dma_slave_config dma_sconfig;
+
+bool tegra_apb_dma_init(void)
+{
+ dma_cap_mask_t mask;
+
+ mutex_lock(&tegra_apb_dma_lock);
+
+ /* Check to see if we raced to setup */
+ if (tegra_apb_dma_chan)
+ goto skip_init;
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+ tegra_apb_dma_chan = dma_request_channel(mask, NULL, NULL);
+ if (!tegra_apb_dma_chan) {
+ /*
+ * This is common until the device is probed, so don't
+ * shout about it.
+ */
+ pr_debug("%s: can not allocate dma channel\n", __func__);
+ goto err_dma_alloc;
+ }
+
+ tegra_apb_bb = dma_alloc_coherent(NULL, sizeof(u32),
+ &tegra_apb_bb_phys, GFP_KERNEL);
+ if (!tegra_apb_bb) {
+ pr_err("%s: can not allocate bounce buffer\n", __func__);
+ goto err_buff_alloc;
+ }
+
+ dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ dma_sconfig.slave_id = TEGRA_DMA_REQ_SEL_CNTR;
+ dma_sconfig.src_maxburst = 1;
+ dma_sconfig.dst_maxburst = 1;
+
+skip_init:
+ mutex_unlock(&tegra_apb_dma_lock);
+ return true;
+
+err_buff_alloc:
+ dma_release_channel(tegra_apb_dma_chan);
+ tegra_apb_dma_chan = NULL;
+
+err_dma_alloc:
+ mutex_unlock(&tegra_apb_dma_lock);
+ return false;
+}
+
+static void apb_dma_complete(void *args)
+{
+ complete(&tegra_apb_wait);
+}
+
+static int do_dma_transfer(unsigned long apb_add,
+ enum dma_transfer_direction dir)
+{
+ struct dma_async_tx_descriptor *dma_desc;
+ int ret;
+
+ if (dir == DMA_DEV_TO_MEM)
+ dma_sconfig.src_addr = apb_add;
+ else
+ dma_sconfig.dst_addr = apb_add;
+
+ ret = dmaengine_slave_config(tegra_apb_dma_chan, &dma_sconfig);
+ if (ret)
+ return ret;
+
+ dma_desc = dmaengine_prep_slave_single(tegra_apb_dma_chan,
+ tegra_apb_bb_phys, sizeof(u32), dir,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!dma_desc)
+ return -EINVAL;
+
+ dma_desc->callback = apb_dma_complete;
+ dma_desc->callback_param = NULL;
+
+ INIT_COMPLETION(tegra_apb_wait);
+
+ dmaengine_submit(dma_desc);
+ dma_async_issue_pending(tegra_apb_dma_chan);
+ ret = wait_for_completion_timeout(&tegra_apb_wait,
+ msecs_to_jiffies(50));
+
+ if (WARN(ret == 0, "apb read dma timed out")) {
+ dmaengine_terminate_all(tegra_apb_dma_chan);
+ return -EFAULT;
+ }
+ return 0;
+}
+
+static u32 tegra_apb_readl_using_dma(unsigned long offset)
+{
+ int ret;
+
+ if (!tegra_apb_dma_chan && !tegra_apb_dma_init())
+ return tegra_apb_readl_direct(offset);
+
+ mutex_lock(&tegra_apb_dma_lock);
+ ret = do_dma_transfer(offset, DMA_DEV_TO_MEM);
+ if (ret < 0) {
+ pr_err("error in reading offset 0x%08lx using dma\n", offset);
+ *(u32 *)tegra_apb_bb = 0;
+ }
+ mutex_unlock(&tegra_apb_dma_lock);
+ return *((u32 *)tegra_apb_bb);
+}
+
+static void tegra_apb_writel_using_dma(u32 value, unsigned long offset)
+{
+ int ret;
+
+ if (!tegra_apb_dma_chan && !tegra_apb_dma_init()) {
+ tegra_apb_writel_direct(value, offset);
+ return;
+ }
+
+ mutex_lock(&tegra_apb_dma_lock);
+ *((u32 *)tegra_apb_bb) = value;
+ ret = do_dma_transfer(offset, DMA_MEM_TO_DEV);
+ if (ret < 0)
+ pr_err("error in writing offset 0x%08lx using dma\n", offset);
+ mutex_unlock(&tegra_apb_dma_lock);
+}
+#endif
+#else
+#define tegra_apb_readl_using_dma tegra_apb_readl_direct
+#define tegra_apb_writel_using_dma tegra_apb_writel_direct
+#endif
+
+typedef u32 (*apbio_read_fptr)(unsigned long offset);
+typedef void (*apbio_write_fptr)(u32 value, unsigned long offset);
+
+static apbio_read_fptr apbio_read;
+static apbio_write_fptr apbio_write;
+
+static u32 tegra_apb_readl_direct(unsigned long offset)
+{
+ return readl(IO_TO_VIRT(offset));
+}
+
+static void tegra_apb_writel_direct(u32 value, unsigned long offset)
+{
+ writel(value, IO_TO_VIRT(offset));
+}
+
+void tegra_apb_io_init(void)
+{
+ /* Need to use dma only when it is Tegra20 based platform */
+ if (of_machine_is_compatible("nvidia,tegra20") ||
+ !of_have_populated_dt()) {
+ apbio_read = tegra_apb_readl_using_dma;
+ apbio_write = tegra_apb_writel_using_dma;
+ } else {
+ apbio_read = tegra_apb_readl_direct;
+ apbio_write = tegra_apb_writel_direct;
+ }
+}
+
+u32 tegra_apb_readl(unsigned long offset)
+{
+ return apbio_read(offset);
+}
+
+void tegra_apb_writel(u32 value, unsigned long offset)
+{
+ apbio_write(value, offset);
+}