[coreboot-gerrit] New patch to review for coreboot: 5425839 Nyan: Set I2S1 Source to CLK_M

[Marc Jones (marc.jones@se-eng.com)]

Marc Jones (marc.jones at se-eng.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/7457

-gerrit

commit 54258391698cf28b3765bfcbd2e9e6ebe5ebe34d
Author: Daisuke Nojiri <dnojiri at chromium.org>
Date:   Wed Mar 26 15:04:10 2014 -0700

    Nyan: Set I2S1 Source to CLK_M
    
    This is required to send 1.5Mhz clock to Max98090 and get a right beep sound.
    
    BUG=chrome-os-partner:26609
    TEST=Booted Nyan. Verified Max98090 can beep. Measured frequency by smartphone.
    BRANCH=none
    Original-Signed-off-by: Daisuke Nojiri <dnojiri at chromium.org>
    Original-Change-Id: Ie3ff6df6759cb23d78dc05069553ddb4eb8e508a
    Original-Reviewed-on: https://chromium-review.googlesource.com/191791
    Original-Reviewed-by: Hung-Te Lin <hungte at chromium.org>
    
    (cherry picked from commit 2f75a147f26ac334fff174a1f9618a2bbe290fe9)
    Signed-off-by: Marc Jones <marc.jones at se-eng.com>
    
    Change-Id: If8c7871dc8202f98ccf23fb0afad1e7745fbf174
---
 src/mainboard/google/nyan/mainboard.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/mainboard/google/nyan/mainboard.c b/src/mainboard/google/nyan/mainboard.c
index dbca03c..a96236b 100644
--- a/src/mainboard/google/nyan/mainboard.c
+++ b/src/mainboard/google/nyan/mainboard.c
@@ -53,10 +53,11 @@ static void set_clock_sources(void)
 	clock_configure_irregular_source(extperiph1, CLK_M, 12000, 3);
 
 	/*
-	 * I2S1 can use either PLLP or PLLA. Using PLLP is sufficient now since
-	 * we only need 4.8MHz. Note the source id of PLLP for I2S is 4.
+	 * We need 1.5MHz. So, we use CLK_M. CLK_DIVIDER macro returns a divisor
+	 * (0xe) a little bit off from the ideal value (0xd) but it's good
+	 * enough for beeps. The source id of CLK_M for I2S is 6.
 	 */
-	clock_configure_irregular_source(i2s1, PLLP, 4800, 4);
+	clock_configure_irregular_source(i2s1, CLK_M, 1500, 6);
 
 	/* Note source id of PLLP for HOST1x is 4. */
 	clock_configure_irregular_source(host1x, PLLP, 408000, 4);