Hello.
On 29-06-2012 13:11, Ruslan Bilovol wrote:
The OMAP4 EHCI controller has the following defect (errata ID i687):
Title:
USB TLL Hold Timing Violation
Description:
There is a timing hold violation on an internal logic on
the clock USB TLL path resulting in a systematic connection
failure on the TLL link
WORKAROUND:
As part of workaround, next should be done:
Set the I/O drive strength to 1.
Depending which USB host subsystem is used,
• Port B1 used: Set CONTROL.CONTROL_SMART2IO_PADCONF_2[11] USBB1_DR0_DS = 0x1
• Port B2 used: Set CONTROL.CONTROL_SMART2IO_PADCONF_2[12] USBB2_DR0_DS = 0x1
All OMAP4430 devices are impacted.
Signed-off-by: Ruslan Bilovol<ruslan.bilovol@xxxxxx>
---
arch/arm/mach-omap2/usb-host.c | 17 +++++++++++++++++
1 files changed, 17 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mach-omap2/usb-host.c b/arch/arm/mach-omap2/usb-host.c
index dde8a11..3a6f2a2 100644
--- a/arch/arm/mach-omap2/usb-host.c
+++ b/arch/arm/mach-omap2/usb-host.c
[...]
@@ -252,6 +253,14 @@ void __init setup_4430ehci_io_mux(const enum usbhs_omap_port_mode *port_mode)
OMAP_PIN_INPUT_PULLDOWN);
omap_mux_init_signal("usbb1_ulpitll_dat7",
OMAP_PIN_INPUT_PULLDOWN);
+
+ /* Errata i687: set I/O drive strength to 1 */
+ if (cpu_is_omap443x()) {
+ u32 val;
Empty line after the declaration block wouldn't hurt...
+ val = omap4_ctrl_pad_readl(OMAP4_CTRL_MODULE_PAD_CORE_CONTROL_SMART2IO_PADCONF_2);
+ val |= OMAP4_USBB1_DR0_DS_MASK;
+ omap4_ctrl_pad_writel(val, OMAP4_CTRL_MODULE_PAD_CORE_CONTROL_SMART2IO_PADCONF_2);
+ }
break;
case OMAP_USBHS_PORT_MODE_UNUSED:
default:
@@ -309,6 +318,14 @@ void __init setup_4430ehci_io_mux(const enum usbhs_omap_port_mode *port_mode)
OMAP_PIN_INPUT_PULLDOWN);
omap_mux_init_signal("usbb2_ulpitll_dat7",
OMAP_PIN_INPUT_PULLDOWN);
+
+ /* Errata i687: set I/O drive strength to 1 */
+ if (cpu_is_omap443x()) {
+ u32 val;
Same here...
+ val = omap4_ctrl_pad_readl(OMAP4_CTRL_MODULE_PAD_CORE_CONTROL_SMART2IO_PADCONF_2);
+ val |= OMAP4_USBB2_DR0_DS_MASK;
+ omap4_ctrl_pad_writel(val, OMAP4_CTRL_MODULE_PAD_CORE_CONTROL_SMART2IO_PADCONF_2);
+ }
break;
case OMAP_USBHS_PORT_MODE_UNUSED:
default:
WBR, Sergei
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