Subject: [PATCH 5/9] clk: davinci: psc-dm365: fix few clocks

From: [email-masked] (David Lechner)
Date: Fri, 25 May 2018 13:11:46 -0500

From: Sekhar Nori <[email-masked]>

Fix parent of EMAC and voice codec PSC clocks. Documentation is clear
on EMAC clock parent, but its not fully clear on parent of voice codec
clock. The implementation chosen is matches arch/arm/mach-davinci/dm365.c.
Add a comment explaining this for posterity.

There is only one power domain on DM365. Fix the power domain of voice
codec and vpss dac modules.

While at it, add a comment explaining how the parent of vpss dac clock was
derived. Note that this patch does not touch the parent of vpss dac clock.

Signed-off-by: Sekhar Nori <[email-masked]>
Reviewed-by: David Lechner <[email-masked]>
---
 drivers/clk/davinci/psc-dm365.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/davinci/psc-dm365.c b/drivers/clk/davinci/psc-dm365.c
index 3ad915f37376..289af3913fb0 100644
--- a/drivers/clk/davinci/psc-dm365.c
+++ b/drivers/clk/davinci/psc-dm365.c
@@ -65,9 +65,22 @@ static const struct davinci_lpsc_clk_info dm365_psc_info[] = {
 	LPSC(31, 0, arm,         pll2_sysclk2, NULL,               LPSC_ALWAYS_ENABLED),
 	LPSC(38, 0, spi3,        pll1_sysclk4, spi3_clkdev,        0),
 	LPSC(39, 0, spi4,        pll1_auxclk,  spi4_clkdev,        0),
-	LPSC(40, 0, emac,        pll2_sysclk4, emac_clkdev,        0),
-	LPSC(44, 1, voice_codec, pll1_sysclk3, voice_codec_clkdev, 0),
-	LPSC(46, 1, vpss_dac,    pll1_sysclk3, vpss_dac_clkdev,    0),
+	LPSC(40, 0, emac,        pll1_sysclk4, emac_clkdev,        0),
+	/*
+	 * The TRM (ARM Subsystem User's Guide) shows two clocks input into
+	 * voice codec module (PLL2 SYSCLK4 with a DIV2 and PLL1 SYSCLK4). Its
+	 * not fully clear from documentation which clock should be considered
+	 * as parent for PSC. The clock chosen here is to maintain
+	 * compatibility with existing code in arch/arm/mach-davinci/dm365.c
+	 */
+	LPSC(44, 0, voice_codec, pll2_sysclk4, voice_codec_clkdev, 0),
+	/*
+	 * Its not fully clear from TRM (ARM Subsystem User's Guide) as to what
+	 * the parent of VPSS DAC LPSC should actually be. PLL1 SYSCLK3 feeds
+	 * into HDVICP and MJCP. The clock chosen here is to remain compatible
+	 * with code existing in arch/arm/mach-davinci/dm365.c
+	 */
+	LPSC(46, 0, vpss_dac,    pll1_sysclk3, vpss_dac_clkdev,    0),
 	LPSC(47, 0, vpss_master, pll1_sysclk5, vpss_master_clkdev, 0),
 	LPSC(50, 0, mjcp,        pll1_sysclk3, NULL,               0),
 	{ }
-- 
2.17.0