From 7db143b89137de06ed289cf8b302f3bbbc5baa1f Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Tue, 16 Sep 2014 15:09:44 -0700 Subject: [PATCH] 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 Cc: Paul Walmsley Cc: Tero Kristo Reviewed-by: Nishanth Menon Signed-off-by: Tony Lindgren --- arch/arm/mach-omap2/omap_hwmod.c | 2 +- arch/arm/mach-omap2/prm3xxx.c | 39 +++++++++++++++++++++++++++++++++++---- 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) -- 2.11.0