[PATCH v4 1/3] ARM: omap: clk: add clk_prepare and clk_unprepare
From: Turquette, Mike <hidden>
Date: 2012-08-30 00:03:49
Also in:
linux-omap
On Wed, Aug 29, 2012 at 1:56 AM, Rajendra Nayak [off-list ref] wrote:
As part of Common Clk Framework (CCF) the clk_enable() operation was split into a clk_prepare() which could sleep, and a clk_enable() which should never sleep. Similarly the clk_disable() was split into clk_disable() and clk_unprepare(). This was needed to handle complex cases where in a clk gate/ungate would require a slow and a fast part to be implemented. None of the clocks below seem to be in the 'complex' clocks category and are just simple clocks which are enabled/disabled through simple register writes. Most of the instances also seem to be called in non-atomic context which means its safe to move all of those from using a clk_enable() to clk_prepare_enable() and clk_disable() to clk_disable_unprepare(). For some others, mainly the ones handled through the hwmod framework there is a possibility that they get called in either an atomic or a non-atomic context. The way these get handled below work only as long as clk_prepare is implemented as a no-op (which is the case today) since this gets called very early at boot while most subsystems are unavailable. Hence these are marked with a *HACK* comment, which says we need to re-visit these once we start doing something meaningful with clk_prepare/clk_unprepare like doing voltage scaling or something that involves i2c. This is in preparation of OMAP moving to CCF. Based on initial changes from Mike turquette. Signed-off-by: Rajendra Nayak <redacted>
Looks good to me. Reviewed-by: Mike Turquette <redacted>
quoted hunk ↗ jump to hunk
--- arch/arm/mach-omap2/board-apollon.c | 4 ++-- arch/arm/mach-omap2/board-h4.c | 6 +++--- arch/arm/mach-omap2/board-omap4panda.c | 2 +- arch/arm/mach-omap2/clock3xxx.c | 8 ++++---- arch/arm/mach-omap2/display.c | 4 ++-- arch/arm/mach-omap2/gpmc.c | 2 +- arch/arm/mach-omap2/omap_hwmod.c | 27 +++++++++++++++++++++++++++ 7 files changed, 40 insertions(+), 13 deletions(-)diff --git a/arch/arm/mach-omap2/board-apollon.c b/arch/arm/mach-omap2/board-apollon.c index e5fa46b..25e8f2f 100644 --- a/arch/arm/mach-omap2/board-apollon.c +++ b/arch/arm/mach-omap2/board-apollon.c@@ -204,7 +204,7 @@ static inline void __init apollon_init_smc91x(void) return; } - clk_enable(gpmc_fck); + clk_prepare_enable(gpmc_fck); rate = clk_get_rate(gpmc_fck); eth_cs = APOLLON_ETH_CS;@@ -248,7 +248,7 @@ static inline void __init apollon_init_smc91x(void) gpmc_cs_free(APOLLON_ETH_CS); } out: - clk_disable(gpmc_fck); + clk_disable_unprepare(gpmc_fck); clk_put(gpmc_fck); }diff --git a/arch/arm/mach-omap2/board-h4.c b/arch/arm/mach-omap2/board-h4.c index ace2048..bd08bef 100644 --- a/arch/arm/mach-omap2/board-h4.c +++ b/arch/arm/mach-omap2/board-h4.c@@ -266,9 +266,9 @@ static inline void __init h4_init_debug(void) return; } - clk_enable(gpmc_fck); + clk_prepare_enable(gpmc_fck); rate = clk_get_rate(gpmc_fck); - clk_disable(gpmc_fck); + clk_disable_unprepare(gpmc_fck); clk_put(gpmc_fck); if (is_gpmc_muxed())@@ -312,7 +312,7 @@ static inline void __init h4_init_debug(void) gpmc_cs_free(eth_cs); out: - clk_disable(gpmc_fck); + clk_disable_unprepare(gpmc_fck); clk_put(gpmc_fck); }diff --git a/arch/arm/mach-omap2/board-omap4panda.c b/arch/arm/mach-omap2/board-omap4panda.c index 70f6d1d..86c2201 100644 --- a/arch/arm/mach-omap2/board-omap4panda.c +++ b/arch/arm/mach-omap2/board-omap4panda.c@@ -172,7 +172,7 @@ static void __init omap4_ehci_init(void) return; } clk_set_rate(phy_ref_clk, 19200000); - clk_enable(phy_ref_clk); + clk_prepare_enable(phy_ref_clk); /* disable the power to the usb hub prior to init and reset phy+hub */ ret = gpio_request_array(panda_ehci_gpios,diff --git a/arch/arm/mach-omap2/clock3xxx.c b/arch/arm/mach-omap2/clock3xxx.c index 794d827..4c1591a 100644 --- a/arch/arm/mach-omap2/clock3xxx.c +++ b/arch/arm/mach-omap2/clock3xxx.c@@ -64,15 +64,15 @@ void __init omap3_clk_lock_dpll5(void) dpll5_clk = clk_get(NULL, "dpll5_ck"); clk_set_rate(dpll5_clk, DPLL5_FREQ_FOR_USBHOST); - clk_enable(dpll5_clk); + clk_prepare_enable(dpll5_clk); /* Program dpll5_m2_clk divider for no division */ dpll5_m2_clk = clk_get(NULL, "dpll5_m2_ck"); - clk_enable(dpll5_m2_clk); + clk_prepare_enable(dpll5_m2_clk); clk_set_rate(dpll5_m2_clk, DPLL5_FREQ_FOR_USBHOST); - clk_disable(dpll5_m2_clk); - clk_disable(dpll5_clk); + clk_disable_unprepare(dpll5_m2_clk); + clk_disable_unprepare(dpll5_clk); return; }diff --git a/arch/arm/mach-omap2/display.c b/arch/arm/mach-omap2/display.c index af1ed7d..5a3afd2 100644 --- a/arch/arm/mach-omap2/display.c +++ b/arch/arm/mach-omap2/display.c@@ -488,7 +488,7 @@ int omap_dss_reset(struct omap_hwmod *oh) for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i > 0; i--, oc++) if (oc->_clk) - clk_enable(oc->_clk); + clk_prepare_enable(oc->_clk); dispc_disable_outputs();@@ -515,7 +515,7 @@ int omap_dss_reset(struct omap_hwmod *oh) for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i > 0; i--, oc++) if (oc->_clk) - clk_disable(oc->_clk); + clk_disable_unprepare(oc->_clk); r = (c == MAX_MODULE_SOFTRESET_WAIT) ? -ETIMEDOUT : 0;diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c index b2b5759..a14d650c 100644 --- a/arch/arm/mach-omap2/gpmc.c +++ b/arch/arm/mach-omap2/gpmc.c@@ -750,7 +750,7 @@ static int __init gpmc_init(void) BUG(); } - clk_enable(gpmc_l3_clk); + clk_prepare_enable(gpmc_l3_clk); l = gpmc_read_reg(GPMC_REVISION); printk(KERN_INFO "GPMC revision %d.%d\n", (l >> 4) & 0x0f, l & 0x0f);diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index 6ca8e51..fb3e110 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c@@ -683,6 +683,15 @@ static int _init_main_clk(struct omap_hwmod *oh) oh->name, oh->main_clk); return -EINVAL; } + /* + * HACK: This needs a re-visit once clk_prepare() is implemented + * to do something meaningful. Today its just a no-op. + * If clk_prepare() is used at some point to do things like + * voltage scaling etc, then this would have to be moved to + * some point where subsystems like i2c and pmic become + * available. + */ + clk_prepare(oh->_clk); if (!oh->_clk->clkdm) pr_warning("omap_hwmod: %s: missing clockdomain for %s.\n",@@ -720,6 +729,15 @@ static int _init_interface_clks(struct omap_hwmod *oh) ret = -EINVAL; } os->_clk = c; + /* + * HACK: This needs a re-visit once clk_prepare() is implemented + * to do something meaningful. Today its just a no-op. + * If clk_prepare() is used at some point to do things like + * voltage scaling etc, then this would have to be moved to + * some point where subsystems like i2c and pmic become + * available. + */ + clk_prepare(os->_clk); } return ret;@@ -747,6 +765,15 @@ static int _init_opt_clks(struct omap_hwmod *oh) ret = -EINVAL; } oc->_clk = c; + /* + * HACK: This needs a re-visit once clk_prepare() is implemented + * to do something meaningful. Today its just a no-op. + * If clk_prepare() is used at some point to do things like + * voltage scaling etc, then this would have to be moved to + * some point where subsystems like i2c and pmic become + * available. + */ + clk_prepare(oc->_clk); } return ret; --1.7.9.5