[U-Boot] [PATCH] i.MX6: Set and clear the gating bits for Phase Fractional Dividers

[Eric Nelson <eric.nelson@boundarydevices.com>]

This addresses silicon errata ERR006282 as described in this
document:
	https://community.freescale.com/docs/DOC-94581

Also implemented in Freescale's 2009.08-based release:

	http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/
	Commit id: b7c5badf94ffbe6cd0845efbb75e16e05e3af404

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
---
 arch/arm/cpu/armv7/mx6/soc.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c
index 8150bff..a390296 100644
--- a/arch/arm/cpu/armv7/mx6/soc.c
+++ b/arch/arm/cpu/armv7/mx6/soc.c
@@ -213,6 +213,34 @@ const struct boot_mode soc_boot_modes[] = {
 
 void s_init(void)
 {
+	struct anatop_regs *anatop = (struct anatop_regs *)ANATOP_BASE_ADDR;
+	int is_6q = is_cpu_type(MXC_CPU_MX6Q);
+	u32 mask480;
+	u32 mask528;
+
+	/* Due to hardware limitation, on MX6Q we need to gate/ungate all PFDs
+	 * to make sure PFD is working right, otherwise, PFDs may
+	 * not output clock after reset, MX6DL and MX6SL have added 396M pfd
+	 * workaround in ROM code, as bus clock need it
+	 */
+
+	mask480 = ANATOP_PFD_CLKGATE_MASK(0) |
+		ANATOP_PFD_CLKGATE_MASK(1) |
+		ANATOP_PFD_CLKGATE_MASK(2) |
+		ANATOP_PFD_CLKGATE_MASK(3);
+	mask528 = ANATOP_PFD_CLKGATE_MASK(0) |
+		ANATOP_PFD_CLKGATE_MASK(1) |
+		ANATOP_PFD_CLKGATE_MASK(3);
+
+	/*
+	 * Don't reset PFD2 on DL/S
+	 */
+	if (is_6q)
+		mask528 |= ANATOP_PFD_CLKGATE_MASK(2);
+	writel(mask480, &anatop->pfd_480_set);
+	writel(mask528, &anatop->pfd_528_set);
+	writel(mask480, &anatop->pfd_480_clr);
+	writel(mask528, &anatop->pfd_528_clr);
 }
 
 #ifdef CONFIG_IMX_HDMI
-- 
1.8.1.2