From 3f394f80645bf0c38a30042ba605c71663331035 Mon Sep 17 00:00:00 2001 From: Peter De Schrijver Date: Thu, 12 Jun 2014 18:36:35 +0300 Subject: [PATCH] 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 Signed-off-by: Stephen Warren Signed-off-by: Thierry Reding --- arch/arm/mach-tegra/apbio.c | 51 ++++++++++++++++++++++--------------- include/soc/tegra/fuse.h | 14 ++++++++++ 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__ */