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- From e76906e8e9dfaeeb22a37706aca493b86e4367bd Mon Sep 17 00:00:00 2001
- From: Linus Walleij <[email protected]>
- Date: Fri, 21 Apr 2017 20:46:12 +0200
- Subject: [PATCH 13/18] usb: host: fotg2: add silicon clock handling
- 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 <[email protected]>
- ---
- ChangeLog v1->v2:
- - Handle probe deferrals on the clock controller, no matter
- how unlikely they are.
- - Send the patch to get Gemini USB rolling and try to get some
- stuff upstream, this patch should be fine on its own.
- ---
- drivers/usb/host/fotg210-hcd.c | 33 +++++++++++++++++++++++++++++----
- drivers/usb/host/fotg210.h | 3 +++
- 2 files changed, 32 insertions(+), 4 deletions(-)
- --- a/drivers/usb/host/fotg210-hcd.c
- +++ b/drivers/usb/host/fotg210-hcd.c
- @@ -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 plat
- 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 plat
-
- 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 pla
- {
- 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;
- --- a/drivers/usb/host/fotg210.h
- +++ b/drivers/usb/host/fotg210.h
- @@ -182,6 +182,9 @@ struct fotg210_hcd { /* one per contro
- # define COUNT(x)
- #endif
-
- + /* silicon clock */
- + struct clk *pclk;
- +
- /* debug files */
- struct dentry *debug_dir;
- };
|
