提交 7db143b8 编写于 作者: T Tony Lindgren

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
b02b9172 ("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: 30a69ef7 ("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: NNishanth Menon <nm@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
上级 69e273c0
......@@ -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();
......
......@@ -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;
......@@ -399,6 +414,15 @@ void omap3xxx_prm_reconfigure_io_chain(void)
omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST);
}
/**
* 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
*
......@@ -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)
......
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