diff options
| -rw-r--r-- | drivers/amba/tegra-ahb.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/drivers/amba/tegra-ahb.c b/drivers/amba/tegra-ahb.c index 30759a55efe4..b0b688c481e8 100644 --- a/drivers/amba/tegra-ahb.c +++ b/drivers/amba/tegra-ahb.c @@ -82,6 +82,16 @@ #define AHB_ARBITRATION_XBAR_CTRL_SMMU_INIT_DONE BIT(17) +/* + * INCORRECT_BASE_ADDR_LOW_BYTE: Legacy kernel DT files for Tegra SoCs + * prior to Tegra124 generally use a physical base address ending in + * 0x4 for the AHB IP block. According to the TRM, the low byte + * should be 0x0. During device probing, this macro is used to detect + * whether the passed-in physical address is incorrect, and if so, to + * correct it. + */ +#define INCORRECT_BASE_ADDR_LOW_BYTE 0x4 + static struct platform_driver tegra_ahb_driver; static const u32 tegra_ahb_gizmo[] = { @@ -124,12 +134,12 @@ struct tegra_ahb { static inline u32 gizmo_readl(struct tegra_ahb *ahb, u32 offset) { - return readl(ahb->regs - 4 + offset); + return readl(ahb->regs + offset); } static inline void gizmo_writel(struct tegra_ahb *ahb, u32 value, u32 offset) { - writel(value, ahb->regs - 4 + offset); + writel(value, ahb->regs + offset); } #ifdef CONFIG_TEGRA_IOMMU_SMMU @@ -258,6 +268,15 @@ static int tegra_ahb_probe(struct platform_device *pdev) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + + /* Correct the IP block base address if necessary */ + if (res && + (res->start & INCORRECT_BASE_ADDR_LOW_BYTE) == + INCORRECT_BASE_ADDR_LOW_BYTE) { + dev_warn(&pdev->dev, "incorrect AHB base address in DT data - enabling workaround\n"); + res->start -= INCORRECT_BASE_ADDR_LOW_BYTE; + } + ahb->regs = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(ahb->regs)) return PTR_ERR(ahb->regs); |