[PATCH] clk: ti: omap5: Fix reboot DPLL lock failure when using ABE TIMERs

[PATCH] clk: ti: omap5: Fix reboot DPLL lock failure when using ABE TIMERs

[H. Nikolaus Schaller]

From: David Shah <dave@ds0.me>

Having the ABE DPLL ref and bypass muxes set to different inputs was
causing the DPLL not to lock when TIMER8 was used, as it is in the Pyra
for the backlight.

This patch fixes this by setting abe_dpll_bypass_clk_mux to sys_32k_ck
in omap5xxx_dt_clk_init.

A similar patch may also be needed for OMAP44xx which has similar code
in omap4xxx_dt_clk_init, but I have not added this as I have no hardware
to test on.

Signed-off-by: David Shah <dave@ds0.me>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---
 drivers/clk/ti/clk-54xx.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/ti/clk-54xx.c b/drivers/clk/ti/clk-54xx.c
index 8694bc9f5fc7f..f0542391ca4bd 100644
--- a/drivers/clk/ti/clk-54xx.c
+++ b/drivers/clk/ti/clk-54xx.c
@@ -605,7 +605,7 @@ static struct ti_dt_clk omap54xx_clks[] = {
 int __init omap5xxx_dt_clk_init(void)
 {
 	int rc;
-	struct clk *abe_dpll_ref, *abe_dpll, *sys_32k_ck, *usb_dpll;
+	struct clk *abe_dpll_ref, *abe_dpll, *abe_dpll_byp, *sys_32k_ck, *usb_dpll;
 
 	ti_dt_clocks_register(omap54xx_clks);
 
@@ -616,6 +616,16 @@ int __init omap5xxx_dt_clk_init(void)
 	abe_dpll_ref = clk_get_sys(NULL, "abe_dpll_clk_mux");
 	sys_32k_ck = clk_get_sys(NULL, "sys_32k_ck");
 	rc = clk_set_parent(abe_dpll_ref, sys_32k_ck);
+
+	/*
+	 * This must also be set to sys_32k_ck to match or
+	 * the ABE DPLL will not lock on a warm reboot when
+	 * ABE timers are used.
+	 */
+	abe_dpll_byp = clk_get_sys(NULL, "abe_dpll_bypass_clk_mux");
+	if (!rc)
+		rc = clk_set_parent(abe_dpll_byp, sys_32k_ck);
+
 	abe_dpll = clk_get_sys(NULL, "dpll_abe_ck");
 	if (!rc)
 		rc = clk_set_rate(abe_dpll, OMAP5_DPLL_ABE_DEFFREQ);
-- 
2.26.2

Re: [PATCH] clk: ti: omap5: Fix reboot DPLL lock failure when using ABE TIMERs

[Tony Lindgren]

* H. Nikolaus Schaller <hns@goldelico.com> [201206 11:19]:
> From: David Shah <dave@ds0.me>
> 
> Having the ABE DPLL ref and bypass muxes set to different inputs was
> causing the DPLL not to lock when TIMER8 was used, as it is in the Pyra
> for the backlight.
> 
> This patch fixes this by setting abe_dpll_bypass_clk_mux to sys_32k_ck
> in omap5xxx_dt_clk_init.
> 
> A similar patch may also be needed for OMAP44xx which has similar code
> in omap4xxx_dt_clk_init, but I have not added this as I have no hardware
> to test on.

Acked-by: Tony Lindgren <tony@atomide.com>