ENGR00221277 MX6DL/S - Set AXI clock to 270MHz

Change AXI_CLK to be sourced from PLL3_PFD1_540MHz, so that it
can run at 270MHz on MX6DL/S. This is required for improving
VPU performance.
Change AXI_CLK to be sourced from  periph_clk just before the DDR
freq  is going to be dropped to 24MHz/50MHz. Change it back
to PLL3_PFD1_540 when the DDR freq is back at 400MHz.

Signed-off-by: Ranjani Vaidyanathan <ra5478@freescale.com>

2 files changed, 23 insertions, 1 deletions

diff --git a/arch/arm/mach-mx6/bus_freq.c b/arch/arm/mach-mx6/bus_freq.c
index 1204da8368cc..bde499dd02a9 100644
--- a/arch/arm/mach-mx6/bus_freq.c
+++ b/arch/arm/mach-mx6/bus_freq.c
@@ -109,6 +109,7 @@ static struct clk *pll1_sw_clk;
 static struct clk *pll3_sw_clk;
 static struct clk *pll2_200;
 static struct clk *mmdc_ch0_axi;
+static struct clk *pll3_540;
 
 static struct delayed_work low_bus_freq_handler;
 
@@ -126,6 +127,14 @@ static void reduce_bus_freq_handler(struct work_struct *work)
 	}
 
 	if (!cpu_is_mx6sl()) {
+		if (cpu_is_mx6dl() &&
+			(clk_get_parent(axi_clk) != periph_clk))
+			/* Set the axi_clk to be sourced from the periph_clk.
+			  * So that its frequency can be lowered down to 50MHz
+			  * or 24MHz as the case may be.
+			  */
+			clk_set_parent(axi_clk, periph_clk);
+
 		clk_enable(pll3);
 		if (lp_audio_freq) {
 			/* Need to ensure that PLL2_PFD_400M is kept ON. */
@@ -302,6 +311,11 @@ int set_high_bus_freq(int high_bus_freq)
 		if (audio_bus_freq_mode)
 			clk_disable(pll2_400);
 
+		/* AXI_CLK is sourced from PLL3_PFD_540 on MX6DL */
+		if (cpu_is_mx6dl() &&
+			clk_get_parent(axi_clk) != pll3_540)
+			clk_set_parent(axi_clk, pll3_540);
+
 		low_bus_freq_mode = 0;
 		audio_bus_freq_mode = 0;
 
@@ -538,6 +552,13 @@ static int __devinit busfreq_probe(struct platform_device *pdev)
 		return PTR_ERR(pll3);
 	}
 
+	pll3_540 = clk_get(NULL, "pll3_pfd_540M");
+	if (IS_ERR(pll3_540)) {
+		printk(KERN_DEBUG "%s: failed to get periph_clk\n",
+		       __func__);
+		return PTR_ERR(pll3_540);
+	}
+
 	pll3_sw_clk = clk_get(NULL, "pll3_sw_clk");
 	if (IS_ERR(pll3_sw_clk)) {
 		printk(KERN_DEBUG "%s: failed to get pll3_sw_clk\n",
diff --git a/arch/arm/mach-mx6/clock.c b/arch/arm/mach-mx6/clock.c
index e2d203c0a0e0..8835c20ad34b 100644
--- a/arch/arm/mach-mx6/clock.c
+++ b/arch/arm/mach-mx6/clock.c
@@ -5409,14 +5409,15 @@ int __init mx6_clocks_init(unsigned long ckil, unsigned long osc,
 		/* pxp & epdc */
 		clk_set_parent(&ipu2_clk, &pll2_pfd_400M);
 		clk_set_rate(&ipu2_clk, 200000000);
+		clk_set_parent(&axi_clk, &pll3_pfd_540M);
 	} else if (cpu_is_mx6q()) {
 		clk_set_parent(&gpu3d_core_clk[0], &mmdc_ch0_axi_clk[0]);
 		clk_set_rate(&gpu3d_core_clk[0], 528000000);
 		clk_set_parent(&ipu2_clk, &mmdc_ch0_axi_clk[0]);
 		clk_set_parent(&ipu1_clk, &mmdc_ch0_axi_clk[0]);
+		clk_set_parent(&axi_clk, &periph_clk);
 	}
 
-	clk_set_parent(&axi_clk, &periph_clk);
 	/* Need to keep PLL3_PFD_540M enabled until AXI is sourced from it. */
 	clk_enable(&axi_clk);