diff mbox series

[2/3] clk: sunxi-ng: h6: Preset hdmi-cec clock parent

Message ID 20190402210623.14988-3-jernej.skrabec@siol.net (mailing list archive)
State New, archived
Headers show
Series clk: sunxi-ng: H6 related clock fixes | expand

Commit Message

Jernej Škrabec April 2, 2019, 9:06 p.m. UTC
H6 manual and BSP clock driver both states that hdmi-cec clock has two
possible parents, osc32k and pll-periph0-2x with 36621 predivider.
Because pll-periph0-2x is always 1.2 GHz, both parents give same
hdmi-cec rate - 32768 Hz, which is exactly the rate needed for HDMI CEC
controller to operate correctly.

However, for some reason, HDMI CEC controller doesn't work if default
parent (osc32k) is used. BSP HDMI driver also always use pll-periph0-2x
as hdmi-cec clock parent.

In order to solve the issue, preset hdmi-cec clock parent to
pll-periph0-2x.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
---
 drivers/clk/sunxi-ng/ccu-sun50i-h6.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Maxime Ripard April 3, 2019, 7:54 a.m. UTC | #1
On Tue, Apr 02, 2019 at 11:06:22PM +0200, Jernej Skrabec wrote:
> H6 manual and BSP clock driver both states that hdmi-cec clock has two
> possible parents, osc32k and pll-periph0-2x with 36621 predivider.
> Because pll-periph0-2x is always 1.2 GHz, both parents give same
> hdmi-cec rate - 32768 Hz, which is exactly the rate needed for HDMI CEC
> controller to operate correctly.
>
> However, for some reason, HDMI CEC controller doesn't work if default
> parent (osc32k) is used. BSP HDMI driver also always use pll-periph0-2x
> as hdmi-cec clock parent.
>
> In order to solve the issue, preset hdmi-cec clock parent to
> pll-periph0-2x.
>
> Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>

Applied, thanks!
Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
diff mbox series

Patch

diff --git a/drivers/clk/sunxi-ng/ccu-sun50i-h6.c b/drivers/clk/sunxi-ng/ccu-sun50i-h6.c
index daf78966555e..33980067b06e 100644
--- a/drivers/clk/sunxi-ng/ccu-sun50i-h6.c
+++ b/drivers/clk/sunxi-ng/ccu-sun50i-h6.c
@@ -656,6 +656,8 @@  static const char * const hdmi_cec_parents[] = { "osc32k", "pll-periph0-2x" };
 static const struct ccu_mux_fixed_prediv hdmi_cec_predivs[] = {
 	{ .index = 1, .div = 36621 },
 };
+
+#define SUN50I_H6_HDMI_CEC_CLK_REG		0xb10
 static struct ccu_mux hdmi_cec_clk = {
 	.enable		= BIT(31),
 
@@ -1200,6 +1202,15 @@  static int sun50i_h6_ccu_probe(struct platform_device *pdev)
 	val &= ~(GENMASK(21, 16) | BIT(0));
 	writel(val | (7 << 16), reg + SUN50I_H6_PLL_AUDIO_REG);
 
+	/*
+	 * First clock parent (osc32K) is unusable for CEC. But since there
+	 * is no good way to force parent switch (both run with same frequency),
+	 * just set second clock parent here.
+	 */
+	val = readl(reg + SUN50I_H6_HDMI_CEC_CLK_REG);
+	val |= BIT(24);
+	writel(val, reg + SUN50I_H6_HDMI_CEC_CLK_REG);
+
 	return sunxi_ccu_probe(pdev->dev.of_node, reg, &sun50i_h6_ccu_desc);
 }