---

yaml
---
r: 313174
b: refs/heads/master
c: 5b39fc0
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b861c275ea5cfeab32241c3c92a203579d5699ff
+refs/heads/master: 5b39fc0bf17028a6b18e57d33f0dcf71f28a8223

trunk/arch/arm/mach-tegra/apbio.c

@@ -17,8 +17,7 @@
 #include <linux/io.h>
 #include <mach/iomap.h>
 #include <linux/of.h>
-
-#ifdef CONFIG_TEGRA_SYSTEM_DMA
+#include <linux/dmaengine.h>
 #include <linux/dma-mapping.h>
 #include <linux/spinlock.h>
 #include <linux/completion.h>
@@ -29,16 +28,18 @@
 
 #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;
@@ -149,6 +150,136 @@ static void tegra_apb_writel_using_dma(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