diff --git a/arch/arm/cpu/armv7/tegra2/clock.c b/arch/arm/cpu/armv7/tegra2/clock.c index 03ac1e3ed0077d843e29e72a28f8077f73ef8b6b..11d2346d83b0fda80052b79f68ac3583779ba990 100644 --- a/arch/arm/cpu/armv7/tegra2/clock.c +++ b/arch/arm/cpu/armv7/tegra2/clock.c @@ -904,6 +904,20 @@ static int clock_set_rate(enum clock_id clkid, u32 n, u32 m, u32 p, u32 cpcon) return 0; } +void clock_ll_start_uart(enum periph_id periph_id) +{ + /* Assert UART reset and enable clock */ + reset_set_enable(periph_id, 1); + clock_enable(periph_id); + clock_ll_set_source(periph_id, 0); /* UARTx_CLK_SRC = 00, PLLP_OUT0 */ + + /* wait for 2us */ + udelay(2); + + /* De-assert reset to UART */ + reset_set_enable(periph_id, 0); +} + int clock_verify(void) { struct clk_pll *pll = get_pll(CLOCK_ID_PERIPH); diff --git a/arch/arm/include/asm/arch-tegra2/clock.h b/arch/arm/include/asm/arch-tegra2/clock.h index 49e9904b57c126b273cb077d3b08f22fa98bead4..080ef18e81dec2602f031ad10f4745cfdbe3c4f0 100644 --- a/arch/arm/include/asm/arch-tegra2/clock.h +++ b/arch/arm/include/asm/arch-tegra2/clock.h @@ -344,6 +344,17 @@ unsigned clock_adjust_periph_pll_div(enum periph_id periph_id, */ unsigned clock_get_rate(enum clock_id clkid); +/** + * Start up a UART using low-level calls + * + * Prior to relocation clock_start_periph_pll() cannot be called. This + * function provides a way to set up a UART using low-level calls which + * do not require BSS. + * + * @param periph_id Peripheral ID of UART to enable (e,g, PERIPH_ID_UART1) + */ +void clock_ll_start_uart(enum periph_id periph_id); + /* * Checks that clocks are valid and prints a warning if not *