[PATCH 5/5] usb: musb-da8xx: remove board-specific clock handling

From: David Lechner
Date: Tue Mar 15 2016 - 18:38:22 EST


This driver should not have to worry about how the clocks are configured
on a system. Added a usb20_phy clock to handle the USB 2.0 PLL clock
externally.

Also changed to using devm_ to simplify code a bit.

Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
---
drivers/usb/musb/da8xx.c | 93 +++++++++++++++++++-----------------------------
1 file changed, 36 insertions(+), 57 deletions(-)

diff --git a/drivers/usb/musb/da8xx.c b/drivers/usb/musb/da8xx.c
index b03d3b8..4e4c872 100644
--- a/drivers/usb/musb/da8xx.c
+++ b/drivers/usb/musb/da8xx.c
@@ -87,50 +87,29 @@ struct da8xx_glue {
struct platform_device *musb;
struct platform_device *phy;
struct clk *clk;
+ struct clk *phy_clk;
};

-/*
- * REVISIT (PM): we should be able to keep the PHY in low power mode most
- * of the time (24 MHz oscillator and PLL off, etc.) by setting POWER.D0
- * and, when in host mode, autosuspending idle root ports... PHY_PLLON
- * (overriding SUSPENDM?) then likely needs to stay off.
- */
-
static inline void phy_on(void)
{
u32 cfgchip2 = __raw_readl(CFGCHIP2);

/*
- * Start the on-chip PHY and its PLL.
+ * Most of the configuration is already done by the usb20_phy clock.
+ * We just need to enable the OTG PHY here.
*/
- cfgchip2 &= ~(CFGCHIP2_RESET | CFGCHIP2_PHYPWRDN | CFGCHIP2_OTGPWRDN);
- cfgchip2 |= CFGCHIP2_PHY_PLLON;
+ cfgchip2 &= ~CFGCHIP2_OTGPWRDN;
__raw_writel(cfgchip2, CFGCHIP2);
-
- pr_info("Waiting for USB PHY clock good...\n");
- while (!(__raw_readl(CFGCHIP2) & CFGCHIP2_PHYCLKGD))
- cpu_relax();
}

static inline void phy_off(void)
{
u32 cfgchip2 = __raw_readl(CFGCHIP2);
-
- /*
- * Ensure that USB 1.1 reference clock is not being sourced from
- * USB 2.0 PHY. Otherwise do not power down the PHY.
- */
- if (!(cfgchip2 & CFGCHIP2_USB1PHYCLKMUX) &&
- (cfgchip2 & CFGCHIP2_USB1SUSPENDM)) {
- pr_warning("USB 1.1 clocked from USB 2.0 PHY -- "
- "can't power it down\n");
- return;
- }
-
/*
- * Power down the on-chip PHY.
+ * Just turn off the OTG PHY. The usb20_phy clock takes care of
+ * everything else.
*/
- cfgchip2 |= CFGCHIP2_PHYPWRDN | CFGCHIP2_OTGPWRDN;
+ cfgchip2 |= CFGCHIP2_OTGPWRDN;
__raw_writel(cfgchip2, CFGCHIP2);
}

@@ -489,38 +468,45 @@ static int da8xx_probe(struct platform_device *pdev)
struct platform_device *musb;
struct da8xx_glue *glue;
struct platform_device_info pinfo;
- struct clk *clk;
-
- int ret = -ENOMEM;
+ int ret;

- glue = kzalloc(sizeof(*glue), GFP_KERNEL);
+ glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
if (!glue) {
dev_err(&pdev->dev, "failed to allocate glue context\n");
- goto err0;
+ return -ENOMEM;
}

- clk = clk_get(&pdev->dev, "usb20");
- if (IS_ERR(clk)) {
+ glue->clk = devm_clk_get(&pdev->dev, "usb20");
+ if (IS_ERR(glue->clk)) {
dev_err(&pdev->dev, "failed to get clock\n");
- ret = PTR_ERR(clk);
- goto err3;
+ return PTR_ERR(glue->clk);
}

- ret = clk_enable(clk);
+ ret = clk_prepare_enable(glue->clk);
if (ret) {
dev_err(&pdev->dev, "failed to enable clock\n");
- goto err4;
+ return ret;
}

- glue->dev = &pdev->dev;
- glue->clk = clk;
+ glue->phy_clk = devm_clk_get(&pdev->dev, "usb20_phy");
+ if (IS_ERR(glue->phy_clk)) {
+ dev_err(&pdev->dev, "failed to get phy clock\n");
+ return PTR_ERR(glue->phy_clk);
+ }
+
+ ret = clk_prepare_enable(glue->phy_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to enable phy clock\n");
+ goto err0;
+ }

+ glue->dev = &pdev->dev;
pdata->platform_ops = &da8xx_ops;

glue->phy = usb_phy_generic_register();
if (IS_ERR(glue->phy)) {
ret = PTR_ERR(glue->phy);
- goto err5;
+ goto err1;
}
platform_set_drvdata(pdev, glue);

@@ -548,24 +534,18 @@ static int da8xx_probe(struct platform_device *pdev)
if (IS_ERR(musb)) {
ret = PTR_ERR(musb);
dev_err(&pdev->dev, "failed to register musb device: %d\n", ret);
- goto err6;
+ goto err2;
}

return 0;

-err6:
+err2:
usb_phy_generic_unregister(glue->phy);
-
-err5:
- clk_disable(clk);
-
-err4:
- clk_put(clk);
-
-err3:
- kfree(glue);
-
+err1:
+ clk_disable_unprepare(glue->phy_clk);
err0:
+ clk_disable_unprepare(glue->clk);
+
return ret;
}

@@ -575,9 +555,8 @@ static int da8xx_remove(struct platform_device *pdev)

platform_device_unregister(glue->musb);
usb_phy_generic_unregister(glue->phy);
- clk_disable(glue->clk);
- clk_put(glue->clk);
- kfree(glue);
+ clk_disable_unprepare(glue->phy_clk);
+ clk_disable_unprepare(glue->clk);

return 0;
}
--
1.9.1