From 96835af970e5d6aeedf868e53590a947be5e4a7a Mon Sep 17 00:00:00 2001 From: Benoit Cousson Date: Tue, 21 Sep 2010 18:57:58 +0200 Subject: [PATCH] OMAP: hwmod: Fix softreset for modules with optional clocks Some modules (like GPIO, DSS...) require optionals clock to be enabled in order to complete the sofreset properly. Add a HWMOD_CONTROL_OPT_CLKS_IN_RESET flag to force all optional clocks to be enabled before reset. Disabled them once the reset is done. TODO: For the moment it is very hard to understand from the HW spec, which optional clock is needed and which one is not. So the current approach will enable all the optional clocks. Paul proposed a much finer approach that will allow to tag only the needed clock in the optional clock table. This might be doable as soon as we have a clear understanding of these dependencies. Reported-by: Partha Basak Signed-off-by: Benoit Cousson Signed-off-by: Paul Walmsley Cc: Kevin Hilman --- arch/arm/mach-omap2/omap_hwmod.c | 51 ++++++++++++++++++-- arch/arm/plat-omap/include/plat/omap_hwmod.h | 5 ++ 2 files changed, 51 insertions(+), 5 deletions(-) diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index 5027879b062f..f320cfb911d5 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -546,6 +546,36 @@ static int _disable_clocks(struct omap_hwmod *oh) return 0; } +static void _enable_optional_clocks(struct omap_hwmod *oh) +{ + struct omap_hwmod_opt_clk *oc; + int i; + + pr_debug("omap_hwmod: %s: enabling optional clocks\n", oh->name); + + for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i > 0; i--, oc++) + if (oc->_clk) { + pr_debug("omap_hwmod: enable %s:%s\n", oc->role, + oc->_clk->name); + clk_enable(oc->_clk); + } +} + +static void _disable_optional_clocks(struct omap_hwmod *oh) +{ + struct omap_hwmod_opt_clk *oc; + int i; + + pr_debug("omap_hwmod: %s: disabling optional clocks\n", oh->name); + + for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i > 0; i--, oc++) + if (oc->_clk) { + pr_debug("omap_hwmod: disable %s:%s\n", oc->role, + oc->_clk->name); + clk_disable(oc->_clk); + } +} + /** * _find_mpu_port_index - find hwmod OCP slave port ID intended for MPU use * @oh: struct omap_hwmod * @@ -976,8 +1006,9 @@ static int _read_hardreset(struct omap_hwmod *oh, const char *name) */ static int _reset(struct omap_hwmod *oh) { - u32 r, v; + u32 v; int c = 0; + int ret = 0; if (!oh->class->sysc || !(oh->class->sysc->sysc_flags & SYSC_HAS_SOFTRESET)) @@ -990,12 +1021,16 @@ static int _reset(struct omap_hwmod *oh) return -EINVAL; } + /* For some modules, all optionnal clocks need to be enabled as well */ + if (oh->flags & HWMOD_CONTROL_OPT_CLKS_IN_RESET) + _enable_optional_clocks(oh); + pr_debug("omap_hwmod: %s: resetting\n", oh->name); v = oh->_sysc_cache; - r = _set_softreset(oh, &v); - if (r) - return r; + ret = _set_softreset(oh, &v); + if (ret) + goto dis_opt_clks; _write_sysconfig(v, oh); if (oh->class->sysc->sysc_flags & SYSS_HAS_RESET_STATUS) @@ -1020,7 +1055,13 @@ static int _reset(struct omap_hwmod *oh) * _wait_target_ready() or _reset() */ - return (c == MAX_MODULE_SOFTRESET_WAIT) ? -ETIMEDOUT : 0; + ret = (c == MAX_MODULE_SOFTRESET_WAIT) ? -ETIMEDOUT : 0; + +dis_opt_clks: + if (oh->flags & HWMOD_CONTROL_OPT_CLKS_IN_RESET) + _disable_optional_clocks(oh); + + return ret; } /** diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h b/arch/arm/plat-omap/include/plat/omap_hwmod.h index faa08273b1e4..ee53758e1f49 100644 --- a/arch/arm/plat-omap/include/plat/omap_hwmod.h +++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h @@ -369,6 +369,10 @@ struct omap_hwmod_omap4_prcm { * HWMOD_SET_DEFAULT_CLOCKACT: program CLOCKACTIVITY bits at startup * HWMOD_NO_IDLEST : this module does not have idle status - this is the case * only for few initiator modules on OMAP2 & 3. + * HWMOD_CONTROL_OPT_CLKS_IN_RESET: Enable all optional clocks during reset. + * This is needed for devices like DSS that require optional clocks enabled + * in order to complete the reset. Optional clocks will be disabled + * again after the reset. */ #define HWMOD_SWSUP_SIDLE (1 << 0) #define HWMOD_SWSUP_MSTANDBY (1 << 1) @@ -377,6 +381,7 @@ struct omap_hwmod_omap4_prcm { #define HWMOD_NO_OCP_AUTOIDLE (1 << 4) #define HWMOD_SET_DEFAULT_CLOCKACT (1 << 5) #define HWMOD_NO_IDLEST (1 << 6) +#define HWMOD_CONTROL_OPT_CLKS_IN_RESET (1 << 7) /* * omap_hwmod._int_flags definitions -- 2.39.5