[PATCH/RFT 01/12] ARM: davinci: da8xx: Enable the usb20 "per" clk on phy_clk_enable

From: ahaslam
Date: Fri Oct 07 2016 - 12:43:45 EST


From: Axel Haslam <ahaslam@xxxxxxxxxxxx>

While probing ochi phy with usb20 phy as a parent clock for usb11_phy,
the usb20_phy clock enable would time out. This is because the usb20
module clock needs to enabled while trying to lock the usb20_phy PLL.

Call clk enable and get for the usb20 peripheral before trying to
enable the phy PLL.

Signed-off-by: Axel Haslam <ahaslam@xxxxxxxxxxxx>
---
arch/arm/mach-davinci/usb-da8xx.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-davinci/usb-da8xx.c b/arch/arm/mach-davinci/usb-da8xx.c
index 9e41a7f..982e105 100644
--- a/arch/arm/mach-davinci/usb-da8xx.c
+++ b/arch/arm/mach-davinci/usb-da8xx.c
@@ -53,11 +53,19 @@ int __init da8xx_register_usb_refclkin(int rate)

static void usb20_phy_clk_enable(struct clk *clk)
{
+ struct clk *usb20_clk;
u32 val;
u32 timeout = 500000; /* 500 msec */

val = readl(DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP2_REG));

+ usb20_clk = clk_get(NULL, "usb20");
+ if (IS_ERR(usb20_clk)) {
+ pr_err("could not get usb20 clk\n");
+ return;
+ }
+
+ clk_prepare_enable(usb20_clk);
/*
* Turn on the USB 2.0 PHY, but just the PLL, and not OTG. The USB 1.1
* host may use the PLL clock without USB 2.0 OTG being used.
@@ -70,11 +78,14 @@ static void usb20_phy_clk_enable(struct clk *clk)
while (--timeout) {
val = readl(DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP2_REG));
if (val & CFGCHIP2_PHYCLKGD)
- return;
+ goto done;
udelay(1);
}

pr_err("Timeout waiting for USB 2.0 PHY clock good.\n");
+done:
+ clk_disable_unprepare(usb20_clk);
+ clk_put(usb20_clk);
}

static void usb20_phy_clk_disable(struct clk *clk)
--
2.7.1