For some hwmods (e.g. DCAN on DRA7) we need the possibility to disable HW_AUTO for the clockdomain while the module is active.
To achieve this there needs to be a refcounting mechanism to indicate whether any module in the clockdomain has requested to disable HW_AUTO. We keep track of this in 'noidlecount'. Hwmod code must use clkdm_hwmod_prevent_hwauto() to prevent HW_AUTO of the clockdomain in the future clkdm_hwmod_hwauto() calls. It must use clkdm_hwmod_allow_hwauto() to allow HW_AUTO in the future clkdm_hwmod_hwauto() calls. Hwmod code must use clkdm_hwmod_allow_hwauto() whenever it needs to request HW_AUTO of any clockdomain. (Typically after it has enabled the module). Signed-off-by: Roger Quadros <[email protected]> --- arch/arm/mach-omap2/clockdomain.c | 71 +++++++++++++++++++++++++++++++++++++++ arch/arm/mach-omap2/clockdomain.h | 5 +++ 2 files changed, 76 insertions(+) diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c index 2da3b5e..a7190d2 100644 --- a/arch/arm/mach-omap2/clockdomain.c +++ b/arch/arm/mach-omap2/clockdomain.c @@ -1212,6 +1212,77 @@ ccd_exit: return 0; } +/* + * prevent future hwauto for this clkdm. If clkdm->usecount becomes hwauto isn't prevented. + * It will only prevnt future hwauto but not bring it out of hwauto. + */ +int clkdm_hwmod_prevent_hwauto(struct clockdomain *clkdm, struct omap_hwmod *oh) +{ + /* The clkdm attribute does not exist yet prior OMAP4 */ + if (cpu_is_omap24xx() || cpu_is_omap34xx()) + return 0; + + if (!clkdm || !oh || !arch_clkdm || !arch_clkdm->clkdm_clk_disable) + return -EINVAL; + + + pwrdm_lock(clkdm->pwrdm.ptr); + clkdm->noidlecount++; + pwrdm_unlock(clkdm->pwrdm.ptr); + + return 0; +} + +/* + * allow future hwauto for this clkdm + * It won't put clkdm into hwauto. use clkdm_hwmod_hwauto() for that. + */ +int clkdm_hwmod_allow_hwauto(struct clockdomain *clkdm, struct omap_hwmod *oh) +{ + /* The clkdm attribute does not exist yet prior OMAP4 */ + if (cpu_is_omap24xx() || cpu_is_omap34xx()) + return 0; + + if (!clkdm || !oh || !arch_clkdm || !arch_clkdm->clkdm_clk_disable) + return -EINVAL; + + + pwrdm_lock(clkdm->pwrdm.ptr); + + if (clkdm->noidlecount == 0) { + pwrdm_unlock(clkdm->pwrdm.ptr); + WARN_ON(1); /* underflow */ + return -ERANGE; + } + + clkdm->noidlecount--; + pwrdm_unlock(clkdm->pwrdm.ptr); + + return 0; +} + +/* + * put clkdm in hwauto if we can. checks noidlecount to see if we can. + */ +int clkdm_hwmod_hwauto(struct clockdomain *clkdm, struct omap_hwmod *oh) +{ + /* The clkdm attribute does not exist yet prior OMAP4 */ + if (cpu_is_omap24xx() || cpu_is_omap34xx()) + return 0; + + if (!clkdm || !oh || !arch_clkdm || !arch_clkdm->clkdm_clk_disable) + return -EINVAL; + + + pwrdm_lock(clkdm->pwrdm.ptr); + if (clkdm->noidlecount == 0) + clkdm_allow_idle_nolock(clkdm); + + pwrdm_unlock(clkdm->pwrdm.ptr); + + return 0; +} + /** * clkdm_hwmod_enable - add an enabled downstream hwmod to this clkdm * @clkdm: struct clockdomain * diff --git a/arch/arm/mach-omap2/clockdomain.h b/arch/arm/mach-omap2/clockdomain.h index 77bab5f..8c491be 100644 --- a/arch/arm/mach-omap2/clockdomain.h +++ b/arch/arm/mach-omap2/clockdomain.h @@ -114,6 +114,7 @@ struct omap_hwmod; * @wkdep_srcs: Clockdomains that can be told to wake this powerdomain up * @sleepdep_srcs: Clockdomains that can be told to keep this clkdm from inact * @usecount: Usecount tracking + * @noidlecount: Noidle count tracking. Domain won't be auto idled this is > 0. * @node: list_head to link all clockdomains together * * @prcm_partition should be a macro from mach-omap2/prcm44xx.h (OMAP4 only) @@ -138,6 +139,7 @@ struct clockdomain { struct clkdm_dep *wkdep_srcs; struct clkdm_dep *sleepdep_srcs; int usecount; + int noidlecount; struct list_head node; }; @@ -211,6 +213,9 @@ int clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk); int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk); int clkdm_hwmod_enable(struct clockdomain *clkdm, struct omap_hwmod *oh); int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh); +int clkdm_hwmod_prevent_hwauto(struct clockdomain *clkdm, struct omap_hwmod *oh); +int clkdm_hwmod_allow_hwauto(struct clockdomain *clkdm, struct omap_hwmod *oh); +int clkdm_hwmod_hwauto(struct clockdomain *clkdm, struct omap_hwmod *oh); extern void __init omap242x_clockdomains_init(void); extern void __init omap243x_clockdomains_init(void); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
