diff options
| author | Stephen Warren <swarren@nvidia.com> | 2012-01-03 12:05:47 +0000 |
|---|---|---|
| committer | Olof Johansson <olof@lixom.net> | 2012-02-06 18:24:59 -0800 |
| commit | e53b7d87cc375fbe428551651094fb676764aae3 (patch) | |
| tree | daea897501425cdd5bf68ed6f9b8eeb0e266993b /arch/arm | |
| parent | cb3732d0dc9df198c889a26210b6b27bc51a1c4a (diff) | |
ARM: tegra: Support Tegra30 in decompressor UART setup
On Tegra20, the UART clock runs at 216MHz, whereas on Tegra30 it runs at
408MHz. Modify arch_decomp_setup() to detect Tegra20-vs-Tegra30 at run-
time, and program the correct divisor.
This makes uncompressor messages work correctly on Tegra30. This also
fixes early printk, assuming zImage is used and this setup code runs.
v2: Use CHIPID register to differentiate between chips, rather than a
GIC register. This should be more future-proof. Volatile is required
to prevent the compiler transforming the 32-bit apb_misc register read
into an 8-bit read of address 1 higher, since the HW only supports 32-
bit accesses, and will hang on an 8-bit access.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/mach-tegra/include/mach/uncompress.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/arm/mach-tegra/include/mach/uncompress.h b/arch/arm/mach-tegra/include/mach/uncompress.h index 4e8323770c79..39bd5e5a1afd 100644 --- a/arch/arm/mach-tegra/include/mach/uncompress.h +++ b/arch/arm/mach-tegra/include/mach/uncompress.h @@ -45,15 +45,23 @@ static inline void flush(void) static inline void arch_decomp_setup(void) { + volatile u32 *apb_misc = (volatile u32 *)TEGRA_APB_MISC_BASE; + u32 chip, div; volatile u8 *uart = (volatile u8 *)TEGRA_DEBUG_UART_BASE; int shift = 2; if (uart == NULL) return; + chip = (apb_misc[0x804 / 4] >> 8) & 0xff; + if (chip == 0x20) + div = 0x0075; + else + div = 0x00dd; + uart[UART_LCR << shift] |= UART_LCR_DLAB; - uart[UART_DLL << shift] = 0x75; - uart[UART_DLM << shift] = 0x0; + uart[UART_DLL << shift] = div & 0xff; + uart[UART_DLM << shift] = div >> 8; uart[UART_LCR << shift] = 3; } |