From: Rajendra Nayak Date: Sun, 10 Jul 2011 11:57:07 +0000 (-0600) Subject: OMAP2+: hwmod: Follow the recommended PRCM module enable sequence X-Git-Tag: firefly_0821_release~3680^2~4840^2^2~1 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=665d001338b494d6d62810aa99b4c0fa1a0884b9;p=firefly-linux-kernel-4.4.55.git OMAP2+: hwmod: Follow the recommended PRCM module enable sequence On OMAP4, the PRCM recommended sequence for enabling a module after power-on-reset is: -1- Force clkdm to SW_WKUP -2- Enabling the clocks -3- Configure desired module mode to "enable" or "auto" -4- Wait for the desired module idle status to be FUNC -5- Program clkdm in HW_AUTO(if supported) This sequence applies to all older OMAPs' as well, however since they use autodeps, it makes sure that no clkdm is in IDLE, and hence not requiring a force SW_WKUP when a module is being enabled. OMAP4 does not need to support autodeps, because of the dyanamic dependency feature, wherein the HW takes care of waking up a clockdomain from idle and hence the module, whenever an interconnect access happens to the given module. Implementing the sequence for OMAP4 requires the clockdomain handling that is currently done in clock framework to be done as part of hwmod framework since the step -4- above to "Wait for the desired module idle status to be FUNC" is done as part of hwmod framework. Signed-off-by: Rajendra Nayak [b-cousson@ti.com: Adapt it to the new clkdm hwmod attribute and API] Signed-off-by: Benoit Cousson Cc: Paul Walmsley [paul@pwsan.com: dropped mach-omap2/clock.c changes; modified to only call the clockdomain code if oh->clkdm is set; disable clock->clockdomain interaction on OMAP4] Signed-off-by: Paul Walmsley --- diff --git a/arch/arm/mach-omap2/clock44xx_data.c b/arch/arm/mach-omap2/clock44xx_data.c index 257882028492..dc79b39abb8f 100644 --- a/arch/arm/mach-omap2/clock44xx_data.c +++ b/arch/arm/mach-omap2/clock44xx_data.c @@ -3212,6 +3212,7 @@ int __init omap4xxx_clk_init(void) } clk_init(&omap2_clk_functions); + omap2_clk_disable_clkdm_control(); for (c = omap44xx_clks; c < omap44xx_clks + ARRAY_SIZE(omap44xx_clks); c++) diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index 4424fee5cd5a..84cc0bdda3ae 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -1437,6 +1437,7 @@ static int _reset(struct omap_hwmod *oh) static int _enable(struct omap_hwmod *oh) { int r; + int hwsup = 0; pr_debug("omap_hwmod: %s: enabling\n", oh->name); @@ -1448,14 +1449,6 @@ static int _enable(struct omap_hwmod *oh) return -EINVAL; } - /* Mux pins for device runtime if populated */ - if (oh->mux && (!oh->mux->enabled || - ((oh->_state == _HWMOD_STATE_IDLE) && - oh->mux->pads_dynamic))) - omap_hwmod_mux(oh->mux, _HWMOD_STATE_ENABLED); - - _add_initiator_dep(oh, mpu_oh); - _enable_clocks(oh); /* * If an IP contains only one HW reset line, then de-assert it in order @@ -1466,23 +1459,56 @@ static int _enable(struct omap_hwmod *oh) oh->_state == _HWMOD_STATE_DISABLED) && oh->rst_lines_cnt == 1) _deassert_hardreset(oh, oh->rst_lines[0].name); - r = _wait_target_ready(oh); - if (r) { - pr_debug("omap_hwmod: %s: _wait_target_ready: %d\n", - oh->name, r); - _disable_clocks(oh); + /* Mux pins for device runtime if populated */ + if (oh->mux && (!oh->mux->enabled || + ((oh->_state == _HWMOD_STATE_IDLE) && + oh->mux->pads_dynamic))) + omap_hwmod_mux(oh->mux, _HWMOD_STATE_ENABLED); + + _add_initiator_dep(oh, mpu_oh); - return r; + if (oh->clkdm) { + /* + * A clockdomain must be in SW_SUP before enabling + * completely the module. The clockdomain can be set + * in HW_AUTO only when the module become ready. + */ + hwsup = clkdm_in_hwsup(oh->clkdm); + r = clkdm_hwmod_enable(oh->clkdm, oh); + if (r) { + WARN(1, "omap_hwmod: %s: could not enable clockdomain %s: %d\n", + oh->name, oh->clkdm->name, r); + return r; + } } + + _enable_clocks(oh); _enable_module(oh); - oh->_state = _HWMOD_STATE_ENABLED; + r = _wait_target_ready(oh); + if (!r) { + /* + * Set the clockdomain to HW_AUTO only if the target is ready, + * assuming that the previous state was HW_AUTO + */ + if (oh->clkdm && hwsup) + clkdm_allow_idle(oh->clkdm); - /* Access the sysconfig only if the target is ready */ - if (oh->class->sysc) { - if (!(oh->_int_flags & _HWMOD_SYSCONFIG_LOADED)) - _update_sysc_cache(oh); - _enable_sysc(oh); + oh->_state = _HWMOD_STATE_ENABLED; + + /* Access the sysconfig only if the target is ready */ + if (oh->class->sysc) { + if (!(oh->_int_flags & _HWMOD_SYSCONFIG_LOADED)) + _update_sysc_cache(oh); + _enable_sysc(oh); + } + } else { + _disable_clocks(oh); + pr_debug("omap_hwmod: %s: _wait_target_ready: %d\n", + oh->name, r); + + if (oh->clkdm) + clkdm_hwmod_disable(oh->clkdm, oh); } return r; @@ -1523,6 +1549,8 @@ static int _idle(struct omap_hwmod *oh) * transition to complete properly. */ _disable_clocks(oh); + if (oh->clkdm) + clkdm_hwmod_disable(oh->clkdm, oh); /* Mux pins for device idle if populated */ if (oh->mux && oh->mux->pads_dynamic) @@ -1620,6 +1648,8 @@ static int _shutdown(struct omap_hwmod *oh) pr_warn("omap_hwmod: %s: _wait_target_disable failed\n", oh->name); _disable_clocks(oh); + if (oh->clkdm) + clkdm_hwmod_disable(oh->clkdm, oh); } /* XXX Should this code also force-disable the optional clocks? */