[PATCH v1 1/1] usb: musb: Use read_poll_timeout()

[PATCH v1 1/1] usb: musb: Use read_poll_timeout()

[Andy Shevchenko]

Use read_poll_timeout() instead of open coding it.
In the same time, fix the typo in the error message.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/usb/musb/tusb6010.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/musb/tusb6010.c b/drivers/usb/musb/tusb6010.c
index cbc707fe570f..2ae82e049f88 100644
--- a/drivers/usb/musb/tusb6010.c
+++ b/drivers/usb/musb/tusb6010.c
@@ -21,6 +21,7 @@
 #include <linux/usb.h>
 #include <linux/irq.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
 #include <linux/dma-mapping.h>
@@ -1029,7 +1030,7 @@ static int tusb_musb_start(struct musb *musb)
 	void __iomem	*tbase = musb->ctrl_base;
 	unsigned long	flags;
 	u32		reg;
-	int		i;
+	int		ret;
 
 	/*
 	 * Enable or disable power to TUSB6010. When enabling, turn on 3.3 V and
@@ -1037,17 +1038,13 @@ static int tusb_musb_start(struct musb *musb)
 	 * provide then PGOOD signal to TUSB6010 which will release it from reset.
 	 */
 	gpiod_set_value(glue->enable, 1);
-	msleep(1);
 
 	/* Wait for 100ms until TUSB6010 pulls INT pin down */
-	i = 100;
-	while (i && gpiod_get_value(glue->intpin)) {
-		msleep(1);
-		i--;
-	}
-	if (!i) {
-		pr_err("tusb: Powerup respones failed\n");
-		return -ENODEV;
+	ret = read_poll_timeout(gpiod_get_value, reg, !reg, 1000, 100000, true,
+				glue->intpin);
+	if (ret) {
+		pr_err("tusb: Powerup response failed\n");
+		return ret;
 	}
 
 	spin_lock_irqsave(&musb->lock, flags);
-- 
2.40.0.1.gaa8946217a0b

Re: [PATCH v1 1/1] usb: musb: Use read_poll_timeout()

[Linus Walleij]

On Mon, Jul 3, 2023 at 2:19 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:

> Use read_poll_timeout() instead of open coding it.
> In the same time, fix the typo in the error message.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
(...)
> +       ret = read_poll_timeout(gpiod_get_value, reg, !reg, 1000, 100000, true,
> +                               glue->intpin);

Wow that's really cool. I had no idea that you could use read_poll_timeout()
together with gpiod_get_value() like this!

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH v1 1/1] usb: musb: Use read_poll_timeout()

[Andy Shevchenko]

On Tue, Jul 04, 2023 at 11:08:41AM +0200, Linus Walleij wrote:
> On Mon, Jul 3, 2023 at 2:19 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> 
> > Use read_poll_timeout() instead of open coding it.
> > In the same time, fix the typo in the error message.
> >
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> (...)
> > +       ret = read_poll_timeout(gpiod_get_value, reg, !reg, 1000, 100000, true,
> > +                               glue->intpin);
> 
> Wow that's really cool. I had no idea that you could use read_poll_timeout()
> together with gpiod_get_value() like this!

Yep, after 5f5323a14cad ("iopoll: introduce read_poll_timeout macro").
I just realized that we need to bump the sleep_us parameter as beneath
it divides it by 4, so I would put 5000 there in v2.

> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Thank you!

-- 
With Best Regards,
Andy Shevchenko