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| author | Vincent Palatin <vpalatin@chromium.org> | 2018-03-02 08:55:51 +0100 |
|---|---|---|
| committer | chrome-bot <chrome-bot@chromium.org> | 2018-03-05 00:21:21 -0800 |
| commit | 29c2aa329489eca44490a6445ef591d6c661b74e (patch) | |
| tree | 484804a2d93409b30511f5813e1e364bb25c0eb0 /chip | |
| parent | 55855fd593912aa82cb59c9fa0eafe9c6990d91d (diff) | |
| download | chrome-ec-29c2aa329489eca44490a6445ef591d6c661b74e.tar.gz | |
stm32h7: enable the fast PLL on-demand
Add a new module ID 'MODULE_FAST_CPU'.
When it is enabled with clock_enable_module(MODULE_FAST_CPU, 1), switch
the system clocking to the fast 400-Mhz PLL.
For now, I consider that a single task/user is calling
clock_enable_module(MODULE_FAST_CPU, x), so we don't need to count users
(in a complicated atomic fashion). It's good enough for the current
use-case and we can add the complexity later if we have a real need.
BRANCH=none
BUG=b:67081508
TEST=on ZerbleBarn, with follow-up CL setting
clock_enable_module(MODULE_FAST_CPU,x) around the computation block,
see that computations are fast and the clock goes back to HSI after.
Change-Id: I2aef3ad673ddbffd6fc64c591c54297e94896fa6
Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/945688
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Diffstat (limited to 'chip')
| -rw-r--r-- | chip/stm32/clock-stm32h7.c | 26 |
1 files changed, 3 insertions, 23 deletions
diff --git a/chip/stm32/clock-stm32h7.c b/chip/stm32/clock-stm32h7.c index edbbb6ea32..f0fcdf8f37 100644 --- a/chip/stm32/clock-stm32h7.c +++ b/chip/stm32/clock-stm32h7.c @@ -180,25 +180,9 @@ static void clock_set_osc(enum clock_osc osc) void clock_enable_module(enum module_id module, int enable) { - static uint32_t clock_mask; - int new_mask; - - if (enable) - new_mask = clock_mask | (1 << module); - else - new_mask = clock_mask & ~(1 << module); - - /* Only change clock if needed */ - if ((!!new_mask) != (!!clock_mask)) { - - /* Flush UART before switching clock speed */ - cflush(); -#if 0 /* Power management policy: TODO(b/67081508) not implemented for now */ - clock_set_osc(new_mask ? OSC_PLL : OSC_CSI); -#endif - } - - clock_mask = new_mask; + /* Assume we have a single task using MODULE_FAST_CPU */ + if (module == MODULE_FAST_CPU) + clock_set_osc(enable ? OSC_PLL : OSC_HSI); } void clock_init(void) @@ -224,10 +208,6 @@ void clock_init(void) /* Use more optimized flash latency settings for ACLK = HSI = 64 Mhz */ clock_flash_latency(FLASH_ACLK_64MHZ); - -#if 0 /* Keep default for now: HSI at 64 Mhz */ - clock_set_osc(OSC_PLL); -#endif } static int command_clock(int argc, char **argv) |