[PATCH] i.MX: clk-pllv3: Initially disable PLL_BYPASS bit

* [PATCH] i.MX: clk-pllv3: Initially disable PLL_BYPASS bit
@ 2017-07-11  9:30 Philipp Zabel
  2017-07-11 17:41 ` Andrey Smirnov
  2017-07-12 14:56 ` Lucas Stach
  0 siblings, 2 replies; 6+ messages in thread
From: Philipp Zabel @ 2017-07-11  9:30 UTC (permalink / raw)
  To: barebox; +Cc: Andrey Smirnov

Commit cbff8031b491 ("i.MX: clk-pllv3: Do not touch PLL_BYPASS bit")
overreached a bit by removing the code that disables the PLL_BYPASS bit
for all architectures instead of making an exception for Vybrid and
i.MX6SL. This causes the USB controller on i.MX6Q to run at bypass
frequency and fail:

    barebox@Boundary Devices i.MX6 Quad Nitrogen6x Board:/ usb
    usb: USB: scanning bus for devices...
    usb: Bus 001 Device 001: ID 0000:0000 EHCI Host Controller
    imx-usb 2184200.usb: port(0) reset error

Also, the linux clk-pllv3 driver never looks at or touches the
PLL_BYPASS bit, but expects the bootloader to set it up correctly.

This patch adds code to unconditionally disable the PLL_BYPASS bit
initially, when the PLL clocks are registered.

Cc: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Fixes: cbff8031b491 ("i.MX: clk-pllv3: Do not touch PLL_BYPASS bit")
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 drivers/clk/imx/clk-pllv3.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/clk/imx/clk-pllv3.c b/drivers/clk/imx/clk-pllv3.c
index 0e55a63e9..44642e88f 100644
--- a/drivers/clk/imx/clk-pllv3.c
+++ b/drivers/clk/imx/clk-pllv3.c
@@ -370,6 +370,7 @@ struct clk *imx_clk_pllv3(enum imx_pllv3_type type, const char *name,
 	struct clk_pllv3 *pll;
 	const struct clk_ops *ops;
 	int ret;
+	u32 val;
 
 	pll = xzalloc(sizeof(*pll));
 
@@ -414,6 +415,10 @@ struct clk *imx_clk_pllv3(enum imx_pllv3_type type, const char *name,
 	pll->clk.parent_names = &pll->parent;
 	pll->clk.num_parents = 1;
 
+	val = readl(pll->base);
+	val &= ~BM_PLL_BYPASS;
+	writel(val, pll->base);
+
 	ret = clk_register(&pll->clk);
 	if (ret) {
 		free(pll);
-- 
2.11.0


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