Disable PLL at end of init

This saves power.

Signed-off-by: Randall Spangler <rspangler@chromium.org>

BUG=chrome-os-partner:8798
TEST=manual

Get a proto1 system modified with INA current sensor

1) From chroot:
  dut-control i2c_mux_en:on i2c_mux:rem
  dut-control pp3300_alw_mv pp3300_alw_ma

2) From EC console:
pll
(this should turn the PLL back on; it'll report clock frequency ~66MHz)

3) From chroot:
  dut-control i2c_mux_en:on i2c_mux:rem
  dut-control pp3300_alw_mv pp3300_alw_ma
Current (ma) should be bigger than in step 1

Change-Id: I806953684c57fd60bf481acb01dddffe2f2ad0ed

1 files changed, 4 insertions, 1 deletions

diff --git a/include/clock.h b/include/clock.h
index 081c9c95a9..209f42c0f0 100644
--- a/include/clock.h
+++ b/include/clock.h
@@ -13,9 +13,12 @@
 /* Set the CPU clocks and PLLs. */
 int clock_init(void);
 
-/* Returns the current clock frequency in Hz. */
+/* Return the current clock frequency in Hz. */
 int clock_get_freq(void);
 
+/* Enable or disable the PLL. */
+int clock_enable_pll(int enable);
+
 /* Wait <cycles> system clock cycles.  Simple busy waiting for before
  * clocks/timers are initialized. */
 void clock_wait_cycles(uint32_t cycles);