tegra: add clock_ll_start_uart() to enable UART prior to reloc
Most boards will want to enable a UART early. This function provides
that feature in Tegra architecture code so the code does not need to be
copied on every board.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/arch/arm/cpu/armv7/tegra2/clock.c b/arch/arm/cpu/armv7/tegra2/clock.c
index 03ac1e3..11d2346 100644
--- a/arch/arm/cpu/armv7/tegra2/clock.c
+++ b/arch/arm/cpu/armv7/tegra2/clock.c
@@ -904,6 +904,20 @@
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);