[U-Boot] i.MX6 freeze when running Linux FSL 3.10.9-1.0.0-alpha AND U-Boot 2013.10

[Otavio Salvador]

Hello,

last days I've been trying to isolate the hung cause of a customer
board, and also SabreSD board, when using the Freescale's Linux fork
of 3.10.9 with 2013.10 U-Boot.

The below patch makes it work fine but it does not seem to be possible
to upstream this fix, that way. How you guys thing this could be
properly integrated into U-Boot to not break other boards?

diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c
index a390296..08f3eda 100644
--- a/arch/arm/cpu/armv7/mx6/soc.c
+++ b/arch/arm/cpu/armv7/mx6/soc.c
@@ -131,6 +131,34 @@ static void imx_set_wdog_powerdown(bool enable)
  writew(enable, &wdog2->wmcr);
 }

+static void imx_set_vddpu_power_down(void)
+{
+ struct anatop_regs *anatop = (struct anatop_regs *)ANATOP_BASE_ADDR;
+ u32 val;
+
+ /* need to power down xPU in GPC before turn off PU LDO */
+ val = readl(GPC_BASE_ADDR + 0x260);
+ writel(val | 0x1, GPC_BASE_ADDR + 0x260);
+
+ val = readl(GPC_BASE_ADDR + 0x0);
+ writel(val | 0x1, GPC_BASE_ADDR + 0x0);
+ while (readl(GPC_BASE_ADDR + 0x0) & 0x1)
+ ;
+
+ /* disable VDDPU */
+ val = 0x3e00;
+ writel(val, &anatop->reg_core_clr);
+}
+
+static void imx_set_pcie_phy_power_down(void)
+{
+ u32 val;
+
+ val = readl(IOMUXC_BASE_ADDR + 0x4);
+ val |= 0x1 << 18;
+ writel(val, IOMUXC_BASE_ADDR + 0x4);
+}
+
 int arch_cpu_init(void)
 {
  init_aips();
@@ -139,6 +167,9 @@ int arch_cpu_init(void)

  imx_set_wdog_powerdown(false); /* Disable PDE bit of WMCR register */

+ imx_set_pcie_phy_power_down();
+ imx_set_vddpu_power_down();
+
 #ifdef CONFIG_APBH_DMA
  /* Start APBH DMA */
  mxs_dma_init();
diff --git a/arch/arm/imx-common/cpu.c b/arch/arm/imx-common/cpu.c
index 0cd2538..5cac1a9 100644
--- a/arch/arm/imx-common/cpu.c
+++ b/arch/arm/imx-common/cpu.c
@@ -171,9 +171,21 @@ u32 get_ahb_clk(void)
  return get_periph_clk() / (ahb_podf + 1);
 }

+static void set_anatop_bypass(void)
+{
+ struct anatop_regs *anatop = (struct anatop_regs *)ANATOP_BASE_ADDR;
+ u32 reg = readl(&anatop->reg_core);
+
+ /* bypass VDDARM/VDDSOC */
+ reg = reg | (0x1F << 18) | 0x1F;
+ writel(reg, &anatop->reg_core);
+}
+
 #if defined(CONFIG_VIDEO_IPUV3)
 void arch_preboot_os(void)
 {
+ set_anatop_bypass();
+
  /* disable video before launching O/S */
  ipuv3_fb_shutdown();
 }

Regards,

-- 
Otavio Salvador                             O.S. Systems
http://www.ossystems.com.br        http://code.ossystems.com.br
Mobile: +55 (53) 9981-7854            Mobile: +1 (347) 903-9750