summaryrefslogtreecommitdiffstats
path: root/drivers/soc
diff options
context:
space:
mode:
authorPeter De Schrijver <pdeschrijver@nvidia.com>2014-06-12 18:36:40 +0300
committerThierry Reding <treding@nvidia.com>2014-07-17 14:37:12 +0200
commit0d827a4343b596b71a1741328c4e5687ce654e19 (patch)
tree338b4adf171c306b382c0c4eb577bc10386fc458 /drivers/soc
parent155dfc7b543345ed45521900bbd32c0db4ea266e (diff)
downloadop-kernel-dev-0d827a4343b596b71a1741328c4e5687ce654e19.zip
op-kernel-dev-0d827a4343b596b71a1741328c4e5687ce654e19.tar.gz
soc/tegra: fuse: move APB DMA into Tegra20 fuse driver
The Tegra20 fuse driver is the only user of tegra_apb_readl_using_dma(). Therefore we can simply the code by incorporating the APB DMA handling into the driver directly. tegra_apb_writel_using_dma() is dropped because there are no users. Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com> Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/soc')
-rw-r--r--drivers/soc/tegra/fuse/fuse-tegra20.c79
1 files changed, 76 insertions, 3 deletions
diff --git a/drivers/soc/tegra/fuse/fuse-tegra20.c b/drivers/soc/tegra/fuse/fuse-tegra20.c
index 7a9d0e0..7cb63ab 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra20.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra20.c
@@ -18,6 +18,9 @@
#include <linux/device.h>
#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
@@ -39,18 +42,58 @@ static phys_addr_t fuse_phys;
static struct clk *fuse_clk;
static void __iomem __initdata *fuse_base;
+static DEFINE_MUTEX(apb_dma_lock);
+static DECLARE_COMPLETION(apb_dma_wait);
+static struct dma_chan *apb_dma_chan;
+static struct dma_slave_config dma_sconfig;
+static u32 *apb_buffer;
+static dma_addr_t apb_buffer_phys;
+
+static void apb_dma_complete(void *args)
+{
+ complete(&apb_dma_wait);
+}
+
static u32 tegra20_fuse_readl(const unsigned int offset)
{
int ret;
- u32 val;
+ u32 val = 0;
+ struct dma_async_tx_descriptor *dma_desc;
+
+ mutex_lock(&apb_dma_lock);
+
+ dma_sconfig.src_addr = fuse_phys + FUSE_BEGIN + offset;
+ ret = dmaengine_slave_config(apb_dma_chan, &dma_sconfig);
+ if (ret)
+ goto out;
+
+ dma_desc = dmaengine_prep_slave_single(apb_dma_chan, apb_buffer_phys,
+ sizeof(u32), DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!dma_desc)
+ goto out;
+
+ dma_desc->callback = apb_dma_complete;
+ dma_desc->callback_param = NULL;
+
+ reinit_completion(&apb_dma_wait);
clk_prepare_enable(fuse_clk);
- ret = tegra_apb_readl_using_dma(fuse_phys + FUSE_BEGIN + offset, &val);
+ dmaengine_submit(dma_desc);
+ dma_async_issue_pending(apb_dma_chan);
+ ret = wait_for_completion_timeout(&apb_dma_wait, msecs_to_jiffies(50));
+
+ if (WARN(ret == 0, "apb read dma timed out"))
+ dmaengine_terminate_all(apb_dma_chan);
+ else
+ val = *apb_buffer;
clk_disable_unprepare(fuse_clk);
+out:
+ mutex_unlock(&apb_dma_lock);
- return (ret < 0) ? 0 : val;
+ return val;
}
static const struct of_device_id tegra20_fuse_of_match[] = {
@@ -58,9 +101,35 @@ static const struct of_device_id tegra20_fuse_of_match[] = {
{},
};
+static int apb_dma_init(void)
+{
+ dma_cap_mask_t mask;
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+ apb_dma_chan = dma_request_channel(mask, NULL, NULL);
+ if (!apb_dma_chan)
+ return -EPROBE_DEFER;
+
+ apb_buffer = dma_alloc_coherent(NULL, sizeof(u32), &apb_buffer_phys,
+ GFP_KERNEL);
+ if (!apb_buffer) {
+ dma_release_channel(apb_dma_chan);
+ return -ENOMEM;
+ }
+
+ dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ dma_sconfig.src_maxburst = 1;
+ dma_sconfig.dst_maxburst = 1;
+
+ return 0;
+}
+
static int tegra20_fuse_probe(struct platform_device *pdev)
{
struct resource *res;
+ int err;
fuse_clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(fuse_clk)) {
@@ -73,6 +142,10 @@ static int tegra20_fuse_probe(struct platform_device *pdev)
return -EINVAL;
fuse_phys = res->start;
+ err = apb_dma_init();
+ if (err)
+ return err;
+
if (tegra_fuse_create_sysfs(&pdev->dev, FUSE_SIZE, tegra20_fuse_readl))
return -ENODEV;
OpenPOWER on IntegriCloud