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usb: host: fotg2: add silicon clock handling

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When used in a system with software-controlled silicon clocks,
the FOTG210 needs to grab, prepare and enable the clock.

This is needed on for example the Cortina Gemini, where the
platform will by default gate off the clock unless the
peripheral (in this case the USB driver) grabs and enables
the clock.

If there is no clock available on the platform, we live
without it. Make sure to percolate probe deferrals.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Linus Walleij 2018-09-01 18:03:12 +02:00 committed by Greg Kroah-Hartman
parent 697fa834c3
commit ffa8a31b5b
2 changed files with 32 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
drivers/usb/host/fotg210-hcd.c
View File

@ -31,6 +31,7 @@
#include <linux/uaccess.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <asm/byteorder.h>
#include <asm/irq.h>
@ -5596,7 +5597,7 @@ static int fotg210_hcd_probe(struct platform_device *pdev)
hcd->regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(hcd->regs)) {
retval = PTR_ERR(hcd->regs);
goto failed;
goto failed_put_hcd;
}
hcd->rsrc_start = res->start;
@ -5606,22 +5607,42 @@ static int fotg210_hcd_probe(struct platform_device *pdev)
fotg210->caps = hcd->regs;
/* It's OK not to supply this clock */
fotg210->pclk = clk_get(dev, "PCLK");
if (!IS_ERR(fotg210->pclk)) {
retval = clk_prepare_enable(fotg210->pclk);
if (retval) {
dev_err(dev, "failed to enable PCLK\n");
goto failed_put_hcd;
}
} else if (PTR_ERR(fotg210->pclk) == -EPROBE_DEFER) {
/*
* Percolate deferrals, for anything else,
* just live without the clocking.
*/
retval = PTR_ERR(fotg210->pclk);
goto failed_dis_clk;
}
retval = fotg210_setup(hcd);
if (retval)
goto failed;
goto failed_dis_clk;
fotg210_init(fotg210);
retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
if (retval) {
dev_err(dev, "failed to add hcd with err %d\n", retval);
goto failed;
goto failed_dis_clk;
}
device_wakeup_enable(hcd->self.controller);
return retval;
failed:
failed_dis_clk:
if (!IS_ERR(fotg210->pclk))
clk_disable_unprepare(fotg210->pclk);
failed_put_hcd:
usb_put_hcd(hcd);
fail_create_hcd:
dev_err(dev, "init %s fail, %d\n", dev_name(dev), retval);
@ -5637,6 +5658,10 @@ static int fotg210_hcd_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct usb_hcd *hcd = dev_get_drvdata(dev);
struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
if (!IS_ERR(fotg210->pclk))
clk_disable_unprepare(fotg210->pclk);
if (!hcd)
return 0;

3
drivers/usb/host/fotg210.h
View File

@ -182,6 +182,9 @@ struct fotg210_hcd { /* one per controller */
# define COUNT(x)
#endif
/* silicon clock */
struct clk *pclk;
/* debug files */
struct dentry *debug_dir;
};