lkml.org 
[lkml]   [2017]   [Oct]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] gpio: gpio-dwapb: add optional reset
From
Date
On Wed, 2017-10-11 at 11:34 -0500, Alan Tull wrote:
> Some platforms require reset to be released to allow register
> access.
>
> Signed-off-by: Alan Tull <atull@kernel.org>
> ---
> v2: Request shared controller
> return all errors from reset controller request
> drop conditions on asserting/deasserting reset

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

Could you also update the device tree binding docs [1] to mention the
optional resets phandle?

[1] Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt

regards
Philipp

> ---
> drivers/gpio/gpio-dwapb.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
> index f051c45..0df8cdf 100644
> --- a/drivers/gpio/gpio-dwapb.c
> +++ b/drivers/gpio/gpio-dwapb.c
> @@ -25,6 +25,7 @@
> #include <linux/of_irq.h>
> #include <linux/platform_device.h>
> #include <linux/property.h>
> +#include <linux/reset.h>
> #include <linux/spinlock.h>
> #include <linux/platform_data/gpio-dwapb.h>
> #include <linux/slab.h>
> @@ -97,6 +98,7 @@ struct dwapb_gpio {
> unsigned int nr_ports;
> struct irq_domain *domain;
> unsigned int flags;
> + struct reset_control *rst;
> };
>
> static inline u32 gpio_reg_v2_convert(unsigned int offset)
> @@ -608,6 +610,12 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
> gpio->dev = &pdev->dev;
> gpio->nr_ports = pdata->nports;
>
> + gpio->rst = devm_reset_control_get_optional_shared(dev, NULL);
> + if (IS_ERR(gpio->rst))
> + return PTR_ERR(gpio->rst);
> +
> + reset_control_deassert(gpio->rst);
> +
> gpio->ports = devm_kcalloc(&pdev->dev, gpio->nr_ports,
> sizeof(*gpio->ports), GFP_KERNEL);
> if (!gpio->ports)
> @@ -659,6 +667,7 @@ static int dwapb_gpio_remove(struct platform_device *pdev)
>
> dwapb_gpio_unregister(gpio);
> dwapb_irq_teardown(gpio);
> + reset_control_assert(gpio->rst);
>
> return 0;
> }

\
 
 \ /
  Last update: 2017-10-12 10:20    [W:0.136 / U:0.436 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site