| Message ID | 1400590362-11177-2-git-send-email-elder@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Quoting Alex Elder (2014-05-20 05:52:38) > Add a flag that tracks whether a clock has already been initialized. > This will be used by the next patch to avoid initializing a clock > more than once when it's listed as a prerequisite. > > Signed-off-by: Alex Elder <elder@linaro.org> > --- > drivers/clk/bcm/clk-kona.c | 17 +++++++++++++++-- > drivers/clk/bcm/clk-kona.h | 7 +++++++ > 2 files changed, 22 insertions(+), 2 deletions(-) > > diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c > index d603c4e..d8a7f38 100644 > --- a/drivers/clk/bcm/clk-kona.c > +++ b/drivers/clk/bcm/clk-kona.c > @@ -27,6 +27,9 @@ > #define CCU_ACCESS_PASSWORD 0xA5A500 > #define CLK_GATE_DELAY_LOOP 2000 > > +#define clk_is_initialized(_clk) FLAG_TEST((_clk), KONA, INITIALIZED) > +#define clk_set_initialized(_clk) FLAG_SET((_clk), KONA, INITIALIZED) > + > /* Bitfield operations */ > > /* Produces a mask of set bits covering a range of a 32-bit value */ > @@ -1194,13 +1197,23 @@ static bool __peri_clk_init(struct kona_clk *bcm_clk) > > static bool __kona_clk_init(struct kona_clk *bcm_clk) > { > + bool ret; > + > + if (clk_is_initialized(bcm_clk)) > + return true; > + > switch (bcm_clk->type) { > case bcm_clk_peri: > - return __peri_clk_init(bcm_clk); > + ret = __peri_clk_init(bcm_clk); Hi Alex, Going through this code, it's a bit hard to keep up ;-) Does the call to __peri_clk_init enable the prereq clocks? If so, is their clk->prepare_count and clk->enable_count properly incremented? Thanks, Mike > + break; > default: > + ret = false; > BUG(); > } > - return -EINVAL; > + if (ret) > + clk_set_initialized(bcm_clk); > + > + return ret; > } > > /* Set a CCU and all its clocks into their desired initial state */ > diff --git a/drivers/clk/bcm/clk-kona.h b/drivers/clk/bcm/clk-kona.h > index 2537b30..10e238d 100644 > --- a/drivers/clk/bcm/clk-kona.h > +++ b/drivers/clk/bcm/clk-kona.h > @@ -406,6 +406,7 @@ struct kona_clk { > struct clk_init_data init_data; /* includes name of this clock */ > struct ccu_data *ccu; /* ccu this clock is associated with */ > enum bcm_clk_type type; > + u32 flags; /* BCM_CLK_KONA_FLAGS_* below */ > union { > void *data; > struct peri_clk_data *peri; > @@ -414,6 +415,12 @@ struct kona_clk { > #define to_kona_clk(_hw) \ > container_of(_hw, struct kona_clk, hw) > > +/* > + * Kona clock flags: > + * INITIALIZED clock has been initialized already > + */ > +#define BCM_CLK_KONA_FLAGS_INITIALIZED ((u32)1 << 0) /* Clock initialized */ > + > /* Initialization macro for an entry in a CCU's kona_clks[] array. */ > #define KONA_CLK(_ccu_name, _clk_name, _type) \ > { \ > -- > 1.9.1 >
On 05/23/2014 07:33 PM, Mike Turquette wrote: > Quoting Alex Elder (2014-05-20 05:52:38) >> Add a flag that tracks whether a clock has already been initialized. >> This will be used by the next patch to avoid initializing a clock >> more than once when it's listed as a prerequisite. >> >> Signed-off-by: Alex Elder <elder@linaro.org> >> --- >> drivers/clk/bcm/clk-kona.c | 17 +++++++++++++++-- >> drivers/clk/bcm/clk-kona.h | 7 +++++++ >> 2 files changed, 22 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c >> index d603c4e..d8a7f38 100644 >> --- a/drivers/clk/bcm/clk-kona.c >> +++ b/drivers/clk/bcm/clk-kona.c >> @@ -27,6 +27,9 @@ >> #define CCU_ACCESS_PASSWORD 0xA5A500 >> #define CLK_GATE_DELAY_LOOP 2000 >> >> +#define clk_is_initialized(_clk) FLAG_TEST((_clk), KONA, INITIALIZED) >> +#define clk_set_initialized(_clk) FLAG_SET((_clk), KONA, INITIALIZED) >> + >> /* Bitfield operations */ >> >> /* Produces a mask of set bits covering a range of a 32-bit value */ >> @@ -1194,13 +1197,23 @@ static bool __peri_clk_init(struct kona_clk *bcm_clk) >> >> static bool __kona_clk_init(struct kona_clk *bcm_clk) >> { >> + bool ret; >> + >> + if (clk_is_initialized(bcm_clk)) >> + return true; >> + >> switch (bcm_clk->type) { >> case bcm_clk_peri: >> - return __peri_clk_init(bcm_clk); >> + ret = __peri_clk_init(bcm_clk); > > Hi Alex, > > Going through this code, it's a bit hard to keep up ;-) Here's how the structures are organized: - A Kona clock is either a peripheral or a bus clock, but a lot of things are handled generically at the Kona level of abstraction. - A peripheral clock has a selector (mux), up to two dividers, and a gate. All of these are optional. - A bus clock has a gate, which is optional. (There are a few other things but I'm just ignoring them for now.) - Each of these sort of sub-components (gate, divider, etc.) are handled on their own. In other words, there are gate routines that operate on a gate regardless of whether it's on bus or peripheral clock. - These sub-components are grouped like this because there are some weird gating requirements. (I've said before I wanted to try to split things off where possible to use the common framework code more, but that opportunity hasn't arisen yet.) > Does the call to __peri_clk_init enable the prereq clocks? If so, is > their clk->prepare_count and clk->enable_count properly incremented? My use of the term "enable" is imprecise. The purpose of these *_init() routines is to set the hardware to a known initial state. Right now, *defining* what that state should be has not been sent out for review, but that's the reason it's set up this way. The model is basically, when you want to make a change, you record what the new value should be and the *_commit() it. Special values, used at initialization time, indicate we don't have a desired value but we don't know what the hardware is currently is set to either. When those special values (like BAD_SCALED_DIV_VALUE) are seen, the current value is read from the hardware rather than written. Anyway, to (hopefully) answer your question... All of the prerequisite activity occurs in __kona_clk_init(), which is called for every Kona clock. The first thing that does is call __kona_prereq_init(), in order to set up and initialize (using __kona_clk_init()) the prerequisite clock if there is one. *After* the prerequisite clock is set up, the rest of the original clock initialization occurs, by calling (e.g.) __peri_clk_init(). Sorry to be so verbose but I think it helps to understand the design underlying this stuff. I'm going to be submitting a new version of this series today. It will pull out the clk_lookup field and some comments that you spotted that are just dead code. -Alex > Thanks, > Mike > >> + break; >> default: >> + ret = false; >> BUG(); >> } >> - return -EINVAL; >> + if (ret) >> + clk_set_initialized(bcm_clk); >> + >> + return ret; >> } >> >> /* Set a CCU and all its clocks into their desired initial state */ >> diff --git a/drivers/clk/bcm/clk-kona.h b/drivers/clk/bcm/clk-kona.h >> index 2537b30..10e238d 100644 >> --- a/drivers/clk/bcm/clk-kona.h >> +++ b/drivers/clk/bcm/clk-kona.h >> @@ -406,6 +406,7 @@ struct kona_clk { >> struct clk_init_data init_data; /* includes name of this clock */ >> struct ccu_data *ccu; /* ccu this clock is associated with */ >> enum bcm_clk_type type; >> + u32 flags; /* BCM_CLK_KONA_FLAGS_* below */ >> union { >> void *data; >> struct peri_clk_data *peri; >> @@ -414,6 +415,12 @@ struct kona_clk { >> #define to_kona_clk(_hw) \ >> container_of(_hw, struct kona_clk, hw) >> >> +/* >> + * Kona clock flags: >> + * INITIALIZED clock has been initialized already >> + */ >> +#define BCM_CLK_KONA_FLAGS_INITIALIZED ((u32)1 << 0) /* Clock initialized */ >> + >> /* Initialization macro for an entry in a CCU's kona_clks[] array. */ >> #define KONA_CLK(_ccu_name, _clk_name, _type) \ >> { \ >> -- >> 1.9.1 >>
diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c index d603c4e..d8a7f38 100644 --- a/drivers/clk/bcm/clk-kona.c +++ b/drivers/clk/bcm/clk-kona.c @@ -27,6 +27,9 @@ #define CCU_ACCESS_PASSWORD 0xA5A500 #define CLK_GATE_DELAY_LOOP 2000 +#define clk_is_initialized(_clk) FLAG_TEST((_clk), KONA, INITIALIZED) +#define clk_set_initialized(_clk) FLAG_SET((_clk), KONA, INITIALIZED) + /* Bitfield operations */ /* Produces a mask of set bits covering a range of a 32-bit value */ @@ -1194,13 +1197,23 @@ static bool __peri_clk_init(struct kona_clk *bcm_clk) static bool __kona_clk_init(struct kona_clk *bcm_clk) { + bool ret; + + if (clk_is_initialized(bcm_clk)) + return true; + switch (bcm_clk->type) { case bcm_clk_peri: - return __peri_clk_init(bcm_clk); + ret = __peri_clk_init(bcm_clk); + break; default: + ret = false; BUG(); } - return -EINVAL; + if (ret) + clk_set_initialized(bcm_clk); + + return ret; } /* Set a CCU and all its clocks into their desired initial state */ diff --git a/drivers/clk/bcm/clk-kona.h b/drivers/clk/bcm/clk-kona.h index 2537b30..10e238d 100644 --- a/drivers/clk/bcm/clk-kona.h +++ b/drivers/clk/bcm/clk-kona.h @@ -406,6 +406,7 @@ struct kona_clk { struct clk_init_data init_data; /* includes name of this clock */ struct ccu_data *ccu; /* ccu this clock is associated with */ enum bcm_clk_type type; + u32 flags; /* BCM_CLK_KONA_FLAGS_* below */ union { void *data; struct peri_clk_data *peri; @@ -414,6 +415,12 @@ struct kona_clk { #define to_kona_clk(_hw) \ container_of(_hw, struct kona_clk, hw) +/* + * Kona clock flags: + * INITIALIZED clock has been initialized already + */ +#define BCM_CLK_KONA_FLAGS_INITIALIZED ((u32)1 << 0) /* Clock initialized */ + /* Initialization macro for an entry in a CCU's kona_clks[] array. */ #define KONA_CLK(_ccu_name, _clk_name, _type) \ { \
Add a flag that tracks whether a clock has already been initialized. This will be used by the next patch to avoid initializing a clock more than once when it's listed as a prerequisite. Signed-off-by: Alex Elder <elder@linaro.org> --- drivers/clk/bcm/clk-kona.c | 17 +++++++++++++++-- drivers/clk/bcm/clk-kona.h | 7 +++++++ 2 files changed, 22 insertions(+), 2 deletions(-)