[U-Boot] [PATCH] ARM: keystone2: PLL: Enable glitch free initialization sequence

[Lokesh Vutla]

Update the PLL initialization sequence to avoid glitches while
programming. User guide for the same is available at[1].

[1] http://www.ti.com/lit/ug/sprugv2h/sprugv2h.pdf

Signed-off-by: Lokesh Vutla <lokeshvutla at ti.com>
---
 arch/arm/mach-keystone/clock.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/arm/mach-keystone/clock.c b/arch/arm/mach-keystone/clock.c
index d8804724..68f8980 100644
--- a/arch/arm/mach-keystone/clock.c
+++ b/arch/arm/mach-keystone/clock.c
@@ -163,15 +163,15 @@ void configure_secondary_pll(const struct pll_init_data *data)
 {
 	int pllod = data->pll_od - 1;
 
+	/* Enable Glitch free bypass for ARM PLL */
+	if (cpu_is_k2hk() && data->pll == TETRIS_PLL)
+		clrbits_le32(KS2_MISC_CTRL, MISC_CTL1_ARM_PLL_EN);
+
 	/* Enable Bypass mode */
 	setbits_le32(keystone_pll_regs[data->pll].reg1, CFG_PLLCTL1_ENSAT_MASK);
 	setbits_le32(keystone_pll_regs[data->pll].reg0,
 		     CFG_PLLCTL0_BYPASS_MASK);
 
-	/* Enable Glitch free bypass for ARM PLL */
-	if (cpu_is_k2hk() && data->pll == TETRIS_PLL)
-		clrbits_le32(KS2_MISC_CTRL, MISC_CTL1_ARM_PLL_EN);
-
 	configure_mult_div(data);
 
 	/* Program Output Divider */
@@ -189,10 +189,6 @@ void configure_secondary_pll(const struct pll_init_data *data)
 	if (data->pll == PASS_PLL && cpu_is_k2hk())
 		pll_pa_clk_sel();
 
-	/* Select the Output of ARM PLL as input to ARM */
-	if (data->pll == TETRIS_PLL)
-		setbits_le32(KS2_MISC_CTRL, MISC_CTL1_ARM_PLL_EN);
-
 	clrbits_le32(keystone_pll_regs[data->pll].reg1, CFG_PLLCTL1_RST_MASK);
 	/* Wait for 500 * REFCLK cucles * (PLLD + 1) */
 	sdelay(105000);
@@ -200,6 +196,10 @@ void configure_secondary_pll(const struct pll_init_data *data)
 	/* Switch to PLL mode */
 	clrbits_le32(keystone_pll_regs[data->pll].reg0,
 		     CFG_PLLCTL0_BYPASS_MASK);
+
+	/* Select the Output of ARM PLL as input to ARM */
+	if (cpu_is_k2hk() && data->pll == TETRIS_PLL)
+		setbits_le32(KS2_MISC_CTRL, MISC_CTL1_ARM_PLL_EN);
 }
 
 void init_pll(const struct pll_init_data *data)
-- 
2.10.1