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authorTony Lindgren <tony@atomide.com>2014-09-17 02:09:44 +0400
committerTony Lindgren <tony@atomide.com>2014-09-17 02:09:44 +0400
commit7db143b89137de06ed289cf8b302f3bbbc5baa1f (patch)
treed74d6abac3dcab9772cfda6983c885e530d44636 /arch
parent69e273c0b0a3c337a521d083374c918dc52c666f (diff)
downloadlinux-7db143b89137de06ed289cf8b302f3bbbc5baa1f.tar.xz
ARM: OMAP3: Fix I/O chain clock line assertion timed out error
We are getting "PRM: I/O chain clock line assertion timed out" errors on early omaps for device tree based booting. This is because we are unconditionally calling reconfigure_io_chain while legacy booting has omap3_has_io_chain_ctrl() checks in place in omap_hwmod.c. For device tree based booting, we are calling reconfigure_io_chain unconditionally from pinctrl framework. So we need to add a check for omap3_has_io_chain_ctrl() to avoid the errors for trying to access a register that does not exist. For es3.0, the documentation in "4.11.2 Device Off-Mode Configuration" just mentions PM_WKEN_WKUP[8] bit. For es3.1, there's a new chapter in documentation for "4.11.2.2 I/O Wake-Up Mechanism" that describes the PM_WKEN_WKUP[16] ST_IO_CHAIN bit. So PM_WKEN_WKUP[16] bit did not get added until in es3.1 probaly to fix issues with flakey wake-up events. We are doing proper checks for ST_IO_CHAIN already in id.c and with omap3_has_io_chain_ctrl(). For more information, see also commit b02b917211d5 ("ARM: OMAP3: PM: fix I/O wakeup and I/O chain clock control detection"). Let's fix the issue by selecting the right function during init for reconfigure_io_chain depending on the omap revision. For es3.0 and earlier we need to just toggle EN_IO. By doing this, we can move the check for omap3_has_io_chain_ctrl() from omap_hwmod.c to the init code in prm_3xxx.c. And then we can unconditionally call reconfigure_io_chain. Thanks to Paul Walmsley and Nishanth Menon for help with debugging the issue. Fixes: 30a69ef785e8 ("ARM: OMAP: Move DT wake-up event handling over to use pinctrl-single-omap") Cc: Kevin Hilman <khilman@kernel.org> Cc: Paul Walmsley <paul@pwsan.com> Cc: Tero Kristo <t-kristo@ti.com> Reviewed-by: Nishanth Menon <nm@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mach-omap2/omap_hwmod.c2
-rw-r--r--arch/arm/mach-omap2/prm3xxx.c39
2 files changed, 36 insertions, 5 deletions
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 8fd87a3055bf..9e91a4e7519a 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -2065,7 +2065,7 @@ static void _reconfigure_io_chain(void)
spin_lock_irqsave(&io_chain_lock, flags);
- if (cpu_is_omap34xx() && omap3_has_io_chain_ctrl())
+ if (cpu_is_omap34xx())
omap3xxx_prm_reconfigure_io_chain();
else if (cpu_is_omap44xx())
omap44xx_prm_reconfigure_io_chain();
diff --git a/arch/arm/mach-omap2/prm3xxx.c b/arch/arm/mach-omap2/prm3xxx.c
index 2458be6fc67b..372de3edf4a5 100644
--- a/arch/arm/mach-omap2/prm3xxx.c
+++ b/arch/arm/mach-omap2/prm3xxx.c
@@ -45,7 +45,7 @@ static struct omap_prcm_irq_setup omap3_prcm_irq_setup = {
.ocp_barrier = &omap3xxx_prm_ocp_barrier,
.save_and_clear_irqen = &omap3xxx_prm_save_and_clear_irqen,
.restore_irqen = &omap3xxx_prm_restore_irqen,
- .reconfigure_io_chain = &omap3xxx_prm_reconfigure_io_chain,
+ .reconfigure_io_chain = NULL,
};
/*
@@ -369,15 +369,30 @@ void __init omap3_prm_init_pm(bool has_uart4, bool has_iva)
}
/**
- * omap3xxx_prm_reconfigure_io_chain - clear latches and reconfigure I/O chain
+ * omap3430_pre_es3_1_reconfigure_io_chain - restart wake-up daisy chain
+ *
+ * The ST_IO_CHAIN bit does not exist in 3430 before es3.1. The only
+ * thing we can do is toggle EN_IO bit for earlier omaps.
+ */
+void omap3430_pre_es3_1_reconfigure_io_chain(void)
+{
+ omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD,
+ PM_WKEN);
+ omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD,
+ PM_WKEN);
+ omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN);
+}
+
+/**
+ * omap3_prm_reconfigure_io_chain - clear latches and reconfigure I/O chain
*
* Clear any previously-latched I/O wakeup events and ensure that the
* I/O wakeup gates are aligned with the current mux settings. Works
* by asserting WUCLKIN, waiting for WUCLKOUT to be asserted, and then
* deasserting WUCLKIN and clearing the ST_IO_CHAIN WKST bit. No
- * return value.
+ * return value. These registers are only available in 3430 es3.1 and later.
*/
-void omap3xxx_prm_reconfigure_io_chain(void)
+void omap3_prm_reconfigure_io_chain(void)
{
int i = 0;
@@ -400,6 +415,15 @@ void omap3xxx_prm_reconfigure_io_chain(void)
}
/**
+ * omap3xxx_prm_reconfigure_io_chain - reconfigure I/O chain
+ */
+void omap3xxx_prm_reconfigure_io_chain(void)
+{
+ if (omap3_prcm_irq_setup.reconfigure_io_chain)
+ omap3_prcm_irq_setup.reconfigure_io_chain();
+}
+
+/**
* omap3xxx_prm_enable_io_wakeup - enable wakeup events from I/O wakeup latches
*
* Activates the I/O wakeup event latches and allows events logged by
@@ -656,6 +680,13 @@ static int omap3xxx_prm_late_init(void)
if (!(prm_features & PRM_HAS_IO_WAKEUP))
return 0;
+ if (omap3_has_io_chain_ctrl())
+ omap3_prcm_irq_setup.reconfigure_io_chain =
+ omap3_prm_reconfigure_io_chain;
+ else
+ omap3_prcm_irq_setup.reconfigure_io_chain =
+ omap3430_pre_es3_1_reconfigure_io_chain;
+
omap3xxx_prm_enable_io_wakeup();
ret = omap_prcm_register_chain_handler(&omap3_prcm_irq_setup);
if (!ret)