summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLokesh Vutla <lokeshvutla@ti.com>2014-06-02 10:49:03 +0530
committerTom Rini <trini@ti.com>2014-06-06 17:46:15 -0400
commitccd2f8db814b88bf4f7a7d418048051d259014a4 (patch)
treefca96e748394fad035cfd12a2caf04b743762c9e
parentfa03834fdf62eb40bc2d47c0e4289d6c250cb148 (diff)
ARM: AM43xx: Fix UART clocks enabling
After enabling a module, SW has to wait on IDLEST bit until it is Fully functional. This wait is missing for UART module and there is a immediate access of UART registers after this. So there is a chance of hang on this module( This can happen when we are running from MPU SRAM). So waiting for IDLEST bit. Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
-rw-r--r--arch/arm/cpu/armv7/am33xx/clock_am43xx.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/am33xx/clock_am43xx.c b/arch/arm/cpu/armv7/am33xx/clock_am43xx.c
index d0bc2340c8..31188c85bc 100644
--- a/arch/arm/cpu/armv7/am33xx/clock_am43xx.c
+++ b/arch/arm/cpu/armv7/am33xx/clock_am43xx.c
@@ -53,6 +53,8 @@ const struct dpll_regs dpll_ddr_regs = {
void setup_clocks_for_console(void)
{
+ u32 clkctrl, idlest = MODULE_CLKCTRL_IDLEST_DISABLED;
+
/* Do not add any spl_debug prints in this function */
clrsetbits_le32(&cmwkup->wkclkstctrl, CD_CLKCTRL_CLKTRCTRL_MASK,
CD_CLKCTRL_CLKTRCTRL_SW_WKUP <<
@@ -63,6 +65,13 @@ void setup_clocks_for_console(void)
MODULE_CLKCTRL_MODULEMODE_MASK,
MODULE_CLKCTRL_MODULEMODE_SW_EXPLICIT_EN <<
MODULE_CLKCTRL_MODULEMODE_SHIFT);
+
+ while ((idlest == MODULE_CLKCTRL_IDLEST_DISABLED) ||
+ (idlest == MODULE_CLKCTRL_IDLEST_TRANSITIONING)) {
+ clkctrl = readl(&cmwkup->wkup_uart0ctrl);
+ idlest = (clkctrl & MODULE_CLKCTRL_IDLEST_MASK) >>
+ MODULE_CLKCTRL_IDLEST_SHIFT;
+ }
}
void enable_basic_clocks(void)