The external 32k crystal is optional and by default LFOSC0 is sourced
by a RC oscillator. This adds a function to be called by board code
when the 32k crystal is present and shall be used to source LFOSC0
from the crystal.
Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
---
arch/arm/mach-k3/common.c | 20 ++++++++++++++++++++
include/mach/k3/common.h | 1 +
2 files changed, 21 insertions(+)
diff --git a/arch/arm/mach-k3/common.c b/arch/arm/mach-k3/common.c
index 3922a0ff19..c779e873c9 100644
--- a/arch/arm/mach-k3/common.c
+++ b/arch/arm/mach-k3/common.c
@@ -170,6 +170,26 @@ static void of_delete_node_path(struct device_node *root, const char *path)
of_delete_node(np);
}
+#define MCU_CTRL_MMR0_BASE 0x04500000
+#define MCU_CTRL_LFXOSC_CTRL (MCU_CTRL_MMR0_BASE + 0x8038)
+#define MCU_CTRL_LFXOSC_32K_DISABLE_VAL BIT(7)
+#define MCU_CTRL_DEVICE_CLKOUT_LFOSC_SELECT_VAL (0x3)
+#define MCU_CTRL_DEVICE_CLKOUT_32K_CTRL (MCU_CTRL_MMR0_BASE + 0x8058)
+
+void am625_enable_32k_crystal(void)
+{
+ u32 val;
+
+ /* Enable 32k crystal */
+ val = readl(MCU_CTRL_LFXOSC_CTRL);
+ val &= ~(MCU_CTRL_LFXOSC_32K_DISABLE_VAL);
+ writel(val, MCU_CTRL_LFXOSC_CTRL);
+
+ /* select 32k clock from LFOSC0 */
+ writel(MCU_CTRL_DEVICE_CLKOUT_LFOSC_SELECT_VAL,
+ MCU_CTRL_DEVICE_CLKOUT_32K_CTRL);
+}
+
#define CTRLMMR_WKUP_JTAG_DEVICE_ID (AM625_WKUP_CTRL_MMR0_BASE + 0x18)
#define JTAG_DEV_CORE_NR GENMASK(21, 19)
diff --git a/include/mach/k3/common.h b/include/mach/k3/common.h
index d7ceea51d7..3377dc8895 100644
--- a/include/mach/k3/common.h
+++ b/include/mach/k3/common.h
@@ -6,5 +6,6 @@
void am625_get_bootsource(enum bootsource *src, int *instance);
u64 am625_sdram_size(void);
void am625_register_dram(void);
+void am625_enable_32k_crystal(void);
#endif /* __MACH_K3_COMMON_H */
--
2.39.5
