On Fri, Jan 30, 2015 at 8:13 PM, Fabio Estevam <festevam@xxxxxxxxx> wrote:
> Hi Felipe,
>
> On Fri, Jan 30, 2015 at 7:59 PM, Felipe Balbi <balbi@xxxxxx> wrote:
>
>>> - gpiod_direction_output(nop->gpiod_reset, !asserted);
>>> + if (asserted)
>>> + goto skip_delay;
>>
>> why skip it ?
>
> Let's suppose we have an active-low GPIO USB phy reset pin.
>
> In usb_gen_phy_init() we call nop_reset_set(nop, 0); and 'assert' is zero.
>
> Then we do:
>
> - Put the GPIO into 0
> - Wait a bit
> - Put it back to 1.
>
> In usb_gen_phy_shutdown, we call nop_reset_set(nop, 1) and assert is one.
>
> Then we should simply do:
>
> - Put GPIO reset into 0.
>
> ,as we the PHY is no more in usage.
>
> That's the reason we don't need the delay when assert is one.
>
> Also, the code prior to the gpiod introduction also skips the delay
> for the assert == 1 case, so this patch restores the original
> behaviour.
Or if you prefer we can make nop_reset_set() to only handle the reset case:
--- a/drivers/usb/phy/phy-generic.c
+++ b/drivers/usb/phy/phy-generic.c
@@ -61,14 +61,13 @@ static int nop_set_suspend(struct usb_phy *x, int suspend)
return 0;
}
-static void nop_reset_set(struct usb_phy_generic *nop, int asserted)
+static void nop_reset_set(struct usb_phy_generic *nop)
{
if (!nop->gpiod_reset)
return;
-
- gpiod_direction_output(nop->gpiod_reset, !asserted);
+ gpiod_set_value(nop->gpiod_reset, 1);
usleep_range(10000, 20000);
- gpiod_set_value(nop->gpiod_reset, asserted);
+ gpiod_set_value(nop->gpiod_reset, 0);
}
/* interface to regulator framework */
@@ -150,8 +149,7 @@ int usb_gen_phy_init(struct usb_phy *phy)
if (!IS_ERR(nop->clk))
clk_prepare_enable(nop->clk);
- /* De-assert RESET */
- nop_reset_set(nop, 0);
+ nop_reset_set(nop);
return 0;
}
@@ -161,8 +159,8 @@ void usb_gen_phy_shutdown(struct usb_phy *phy)
{
struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
- /* Assert RESET */
- nop_reset_set(nop, 1);
+ if (nop->gpiod_reset)
+ gpiod_direction_output(nop->gpiod_reset, 1);
if (!IS_ERR(nop->clk))
clk_disable_unprepare(nop->clk);
--
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