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authorPeter De Schrijver <pdeschrijver@nvidia.com>2014-06-12 18:36:35 +0300
committerThierry Reding <treding@nvidia.com>2014-07-17 13:36:44 +0200
commit3f394f80645bf0c38a30042ba605c71663331035 (patch)
tree6acabf07689afc6b71bb0409d100ffb732fcb236
parent304664eab93f9e95a8d28fbd9702ede88bb10cc5 (diff)
ARM: tegra: export apb dma readl/writel
Export APB DMA readl and writel. These are needed because we can't access the fuses directly on Tegra20 without potentially causing a system hang. Also have the APB DMA readl and writel return an error in case of a read failure instead of just returning zero or ignore write failures. 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>
-rw-r--r--arch/arm/mach-tegra/apbio.c51
-rw-r--r--include/soc/tegra/fuse.h14
2 files changed, 45 insertions, 20 deletions
diff --git a/arch/arm/mach-tegra/apbio.c b/arch/arm/mach-tegra/apbio.c
index 5f9647b3f81d..f2488722c79c 100644
--- a/arch/arm/mach-tegra/apbio.c
+++ b/arch/arm/mach-tegra/apbio.c
@@ -32,8 +32,8 @@ 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);
+static int tegra_apb_readl_direct(unsigned long offset, u32 *value);
+static int tegra_apb_writel_direct(u32 value, unsigned long offset);
static struct dma_chan *tegra_apb_dma_chan;
static struct dma_slave_config dma_sconfig;
@@ -128,58 +128,64 @@ static int do_dma_transfer(unsigned long apb_add,
return 0;
}
-static u32 tegra_apb_readl_using_dma(unsigned long offset)
+int tegra_apb_readl_using_dma(unsigned long offset, u32 *value)
{
int ret;
if (!tegra_apb_dma_chan && !tegra_apb_dma_init())
- return tegra_apb_readl_direct(offset);
+ return tegra_apb_readl_direct(offset, value);
mutex_lock(&tegra_apb_dma_lock);
ret = do_dma_transfer(offset, DMA_DEV_TO_MEM);
- if (ret < 0) {
+ if (ret < 0)
pr_err("error in reading offset 0x%08lx using dma\n", offset);
- *(u32 *)tegra_apb_bb = 0;
- }
+ else
+ *value = *tegra_apb_bb;
+
mutex_unlock(&tegra_apb_dma_lock);
- return *((u32 *)tegra_apb_bb);
+
+ return ret;
}
-static void tegra_apb_writel_using_dma(u32 value, unsigned long offset)
+int 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;
- }
+ if (!tegra_apb_dma_chan && !tegra_apb_dma_init())
+ return tegra_apb_writel_direct(value, offset);
mutex_lock(&tegra_apb_dma_lock);
*((u32 *)tegra_apb_bb) = value;
ret = do_dma_transfer(offset, DMA_MEM_TO_DEV);
+ mutex_unlock(&tegra_apb_dma_lock);
if (ret < 0)
pr_err("error in writing offset 0x%08lx using dma\n", offset);
- mutex_unlock(&tegra_apb_dma_lock);
+
+ return ret;
}
#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);
+typedef int (*apbio_read_fptr)(unsigned long offset, u32 *value);
+typedef int (*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)
+static int tegra_apb_readl_direct(unsigned long offset, u32 *value)
{
- return readl(IO_ADDRESS(offset));
+ *value = readl(IO_ADDRESS(offset));
+
+ return 0;
}
-static void tegra_apb_writel_direct(u32 value, unsigned long offset)
+static int tegra_apb_writel_direct(u32 value, unsigned long offset)
{
writel(value, IO_ADDRESS(offset));
+
+ return 0;
}
void tegra_apb_io_init(void)
@@ -197,7 +203,12 @@ void tegra_apb_io_init(void)
u32 tegra_apb_readl(unsigned long offset)
{
- return apbio_read(offset);
+ u32 val;
+
+ if (apbio_read(offset, &val) < 0)
+ return 0;
+ else
+ return val;
}
void tegra_apb_writel(u32 value, unsigned long offset)
diff --git a/include/soc/tegra/fuse.h b/include/soc/tegra/fuse.h
index 0e03f104fbf8..a43a750dd0a3 100644
--- a/include/soc/tegra/fuse.h
+++ b/include/soc/tegra/fuse.h
@@ -27,6 +27,20 @@
u32 tegra_read_chipid(void);
u8 tegra_get_chip_id(void);
+#if defined(CONFIG_TEGRA20_APB_DMA)
+int tegra_apb_readl_using_dma(unsigned long offset, u32 *value);
+int tegra_apb_writel_using_dma(u32 value, unsigned long offset);
+#else
+static inline int tegra_apb_readl_using_dma(unsigned long offset, u32 *value)
+{
+ return -EINVAL;
+}
+static inline int tegra_apb_writel_using_dma(u32 value, unsigned long offset)
+{
+ return -EINVAL;
+}
+#endif /* CONFIG_TEGRA20_APB_DMA */
+
#endif /* __ASSEMBLY__ */
#endif /* __SOC_TEGRA_FUSE_H__ */

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