On Mon, Oct 22, 2012 at 10:24:32AM -0600, Stephen Warren wrote: > On 10/22/2012 02:18 AM, Peter De Schrijver wrote: > >> + > >> +#define checkuart(rp, rv, lhu, bit, uart) \ > >> + /* Load address of CLK_RST register */ \ > >> + movw rp, #TEGRA_CLK_RST_DEVICES_##lhu & 0xffff ; \ > >> + movt rp, #TEGRA_CLK_RST_DEVICES_##lhu >> 16 ; \ > >> + /* Load value from CLK_RST register */ \ > >> + ldr rp, [rp, #0] ; \ > >> + /* Test UART's reset bit */ \ > >> + tst rp, #(1 << bit) ; \ > >> + /* If set, can't use UART; jump to save no UART */ \ > >> + bne 90f ; \ > >> + /* Load address of CLK_OUT_ENB register */ \ > >> + movw rp, #TEGRA_CLK_OUT_ENB_##lhu & 0xffff ; \ > >> + movt rp, #TEGRA_CLK_OUT_ENB_##lhu >> 16 ; \ > >> + /* Load value from CLK_OUT_ENB register */ \ > >> + ldr rp, [rp, #0] ; \ > >> + /* Test UART's clock enable bit */ \ > >> + tst rp, #(1 << bit) ; \ > >> + /* If clear, can't use UART; jump to save no UART */ \ > >> + beq 90f ; \ > >> + /* Passed all tests, load address of UART registers */ \ > >> + movw rp, #TEGRA_UART##uart##_BASE & 0xffff ; \ > >> + movt rp, #TEGRA_UART##uart##_BASE >> 16 ; \ > >> + /* Jump to save UART address */ \ > >> + b 91f > >> > > > > Maybe make this a subroutine? > > The addruart macro (which in turn uses the checkuart macro) is only > allowed to use 3 registers; rp, rv, rtmp. I'm also not 100% sure if the > stack is guaranteed to be set up when addruart is called either. So, I > don't think making this a function is possible. There's no stack. Remember, this stuff can be inserted as early as the front of the kernel assembly code, where there is _nothing_ - the MMU is off so virtual addresses are meaningless. etc. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
