ENGR00313202 ARM: imx: add VPU 352M support for i.MX6Q

When VPU freq is set to 352MHz, it need to source clk
from PLL2_PFD2_396M, and PLL2_PFD2_396M need to change
freq to 352M.

VDDSOC/PU needs to be at highest setpoint when VPU@352Mhz,
cpufreq will be disabled as it will not save any power if
VDDSOC/PU's voltage stays at highest setpoint.

Busfreq will be disabled as it needs PLL2_PFD2 to be
as 396MHz to achieve low power audio freq setpoint.

To enable VPU 352MHz feature, select it in menuconfig,
it is disabled by default.

Signed-off-by: Anson Huang <b20788@freescale.com>

3 files changed, 19 insertions, 2 deletions

diff --git a/arch/arm/mach-imx/busfreq-imx6.c b/arch/arm/mach-imx/busfreq-imx6.c
index 7d0cde0a7ffd..ecc020855fcc 100644
--- a/arch/arm/mach-imx/busfreq-imx6.c
+++ b/arch/arm/mach-imx/busfreq-imx6.c
@@ -1013,11 +1013,12 @@ static struct platform_driver busfreq_driver = {
 
 static int __init busfreq_init(void)
 {
+#ifndef CONFIG_MX6_VPU_352M
         if (platform_driver_register(&busfreq_driver) != 0)
                 return -ENODEV;
 
         printk(KERN_INFO "Bus freq driver module loaded\n");
-
+#endif
         return 0;
 }
 
diff --git a/arch/arm/mach-imx/clk-imx6q.c b/arch/arm/mach-imx/clk-imx6q.c
index 6aaaee22805c..78e616286e1e 100644
--- a/arch/arm/mach-imx/clk-imx6q.c
+++ b/arch/arm/mach-imx/clk-imx6q.c
@@ -701,6 +701,21 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
         /* Set pll4_audio to a value that can derive 5K-88.2KHz and 8K-96KHz */
         clk_set_rate(clk[pll4_audio_div], 541900800);
 
+#ifdef CONFIG_MX6_VPU_352M
+        /*
+         * If VPU 352M is enabled, then PLL2_PDF2 need to be
+         * set to 352M, cpufreq will be disabled as VDDSOC/PU
+         * need to be at highest voltage, scaling cpu freq is
+         * not saving any power, and busfreq will be also disabled
+         * as the PLL2_PFD2 is not at default freq, in a word,
+         * all modules that sourceing clk from PLL2_PFD2 will
+         * be impacted.
+         */
+        clk_set_rate(clk[pll2_pfd2_396m], 352000000);
+        clk_set_parent(clk[vpu_axi_sel], clk[pll2_pfd2_396m]);
+        pr_info("VPU 352M is enabled!\n");
+#endif
+
         /* Set initial power mode */
         imx6_set_lpm(WAIT_CLOCKED);
 
diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index 7ff96e7565aa..9a8fd6f01c62 100644
--- a/arch/arm/mach-imx/mach-imx6q.c
+++ b/arch/arm/mach-imx/mach-imx6q.c
@@ -466,7 +466,8 @@ static void __init imx6q_init_late(void)
                 IMX_CHIP_REVISION_1_0))
                 imx6q_cpuidle_init();
 
-        if (IS_ENABLED(CONFIG_ARM_IMX6_CPUFREQ)) {
+        if (IS_ENABLED(CONFIG_ARM_IMX6_CPUFREQ) &&
+                        !IS_ENABLED(CONFIG_MX6_VPU_352M)) {
                 imx6q_opp_init(&imx6q_cpufreq_pdev.dev);
                 platform_device_register(&imx6q_cpufreq_pdev);
         }