Commit graph

5 commits

Author SHA1 Message Date
wangmengyang
22e21b38f7 component/bt: implement bluetooth modem sleep mode, one mode for BLE only and another for dual mode bluetooth
1. provide options for bluetooth low power mode
2. provide two options for bluetooth low power clock: main XTAL and external 32kHz XTAL
3. provide function and callbacks to control bluetooth low power mode, including enable/disable sleep, software wakeup request, low power clock settings, check power state, etc
4. modify vhci API vhci_host_send_packet to use blocking mode
5. note that DFS and bluetooth modem sleep can not be used together currently.
2018-05-19 15:37:26 +08:00
Ivan Grokhotkov
05a0fbd49b soc/rtc: add a function to wait for slow clock cycle
Some RTC features are synchronized to RTC_SLOW_CLK, so sometimes
software needs to wait for the next slow clock cycle.
This function implements waiting using Timer Group clock calibration
feature.
2017-10-26 19:53:53 +08:00
Ivan Grokhotkov
6353bc40d7 Add support for 32k XTAL as RTC_SLOW_CLK source
- RTC_CNTL_SLOWCLK_FREQ define is removed; rtc_clk_slow_freq_get_hz
  function can be used instead to get an approximate RTC_SLOW_CLK
  frequency

- Clock calibration is performed at startup. The value is saved and used
  for timekeeping and when entering deep sleep.

- When using the 32k XTAL, startup code will wait for the oscillator to
  start up. This can be possibly optimized by starting a separate task
  to wait for oscillator startup, and performing clock switch in that
  task.

- Fix a bug that 32k XTAL would be disabled in rtc_clk_init.

- Fix a rounding error in rtc_clk_cal, which caused systematic frequency
  error.

- Fix an overflow bug which caused rtc_clk_cal to timeout early if the
  slow_clk_cycles argument would exceed certain value

- Improve 32k XTAL oscillator startup time by introducing bootstrapping
  code, which uses internal pullup/pulldown resistors on 32K_N/32K_P
  pins to set better initial conditions for the oscillator.
2017-04-26 12:43:22 +08:00
Ivan Grokhotkov
3323f31cfb soc: implement XTAL frequency detection
ROM code already implements XTAL frequency detection, but it uses the 8M
clock before the clock tuning parameters are initialized. With the
zero clock tuning parameter, 8M clock has significant frequency deviation
at high temperatures, which can lead to erroneous detection of 40 MHz
crystal as a 26 MHz one.

This change adds XTAL frequency detection code to rtc_clk_init routine,
and detection is performed after the 8M clock tuning parameter as been
initialized.
2017-04-24 15:29:30 +08:00
Ivan Grokhotkov
7ee8ee8b7e soc: add source code of rtc_clk, rtc_pm 2017-04-11 15:45:54 +08:00