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[v6,0/2] pinctrl: pinctrl-microchip-sgpio: Extend to call reset driver

Message ID 20211018085754.1066056-1-horatiu.vultur@microchip.com
Headers show
Series pinctrl: pinctrl-microchip-sgpio: Extend to call reset driver | expand

Message

Horatiu Vultur Oct. 18, 2021, 8:57 a.m. UTC 
This allows the driver to call an optional reset driver.

v5->v6:
 - fix warnings reported by 'make dtbs_check'
 - add back the name of the reset line

v4->v5:
 - check the return value of devm_reset_control_get_optional_shared

v3->v4:
 - use devm_reset_control_get_optional_shared
 - remove the expected name of the reset line

v2->v3:
 - fix warnings reported by 'make dtbs_check'

v1->v2:
 - add dt-bindings changes

Horatiu Vultur (2):
  dt-bindings: pinctrl: pinctrl-microchip-sgpio: Add reset binding
  pinctrl: microchip sgpio: use reset driver

 .../bindings/pinctrl/microchip,sparx5-sgpio.yaml           | 7 +++++++
 drivers/pinctrl/pinctrl-microchip-sgpio.c                  | 7 +++++++
 2 files changed, 14 insertions(+)

Comments

Philipp Zabel Oct. 18, 2021, 10:37 a.m. UTC | #1 
Hi Horatiu,

On Mon, 2021-10-18 at 10:57 +0200, Horatiu Vultur wrote:
> On lan966x platform when the switch gets reseted then also the sgpio
> gets reseted. The fix for this is to extend also the sgpio driver to
> call the reset driver which will be reseted only once by the first
> driver that is probed.
> 
> Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> ---
>  drivers/pinctrl/pinctrl-microchip-sgpio.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/pinctrl/pinctrl-microchip-sgpio.c b/drivers/pinctrl/pinctrl-microchip-sgpio.c
> index 072bccdea2a5..78765faa245a 100644
> --- a/drivers/pinctrl/pinctrl-microchip-sgpio.c
> +++ b/drivers/pinctrl/pinctrl-microchip-sgpio.c
> @@ -17,6 +17,7 @@
>  #include <linux/pinctrl/pinmux.h>
>  #include <linux/platform_device.h>
>  #include <linux/property.h>
> +#include <linux/reset.h>
>  
>  #include "core.h"
>  #include "pinconf.h"
> @@ -803,6 +804,7 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
>  	int div_clock = 0, ret, port, i, nbanks;
>  	struct device *dev = &pdev->dev;
>  	struct fwnode_handle *fwnode;
> +	struct reset_control *reset;
>  	struct sgpio_priv *priv;
>  	struct clk *clk;
>  	u32 val;
> @@ -813,6 +815,11 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
>  
>  	priv->dev = dev;
>  
> +	reset = devm_reset_control_get_optional_shared(&pdev->dev, "switch");

This is the first GPIO driver that I am aware of that requests a named
reset control, so I'm still not sure if this should be called "switch"
instead of "gpio" or just "reset", just in case there is a future model
where the GPIO controller reset is not shared with the switch reset.

> +	if (IS_ERR(reset))
> +		return dev_err_probe(dev, PTR_ERR(reset), "Failed to get reset\n");
> +	reset_control_reset(reset);
> +
>  	clk = devm_clk_get(dev, NULL);
>  	if (IS_ERR(clk))
>  		return dev_err_probe(dev, PTR_ERR(clk), "Failed to get clock\n");

But whichever name you choose, the code is

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

regards
Philipp
Horatiu Vultur Oct. 18, 2021, 11:12 a.m. UTC | #2 
The 10/18/2021 12:37, Philipp Zabel wrote:

Hi Philipp,
> 
> Hi Horatiu,
> 
> On Mon, 2021-10-18 at 10:57 +0200, Horatiu Vultur wrote:
> > On lan966x platform when the switch gets reseted then also the sgpio
> > gets reseted. The fix for this is to extend also the sgpio driver to
> > call the reset driver which will be reseted only once by the first
> > driver that is probed.
> >
> > Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> > ---
> >  drivers/pinctrl/pinctrl-microchip-sgpio.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/pinctrl/pinctrl-microchip-sgpio.c b/drivers/pinctrl/pinctrl-microchip-sgpio.c
> > index 072bccdea2a5..78765faa245a 100644
> > --- a/drivers/pinctrl/pinctrl-microchip-sgpio.c
> > +++ b/drivers/pinctrl/pinctrl-microchip-sgpio.c
> > @@ -17,6 +17,7 @@
> >  #include <linux/pinctrl/pinmux.h>
> >  #include <linux/platform_device.h>
> >  #include <linux/property.h>
> > +#include <linux/reset.h>
> >
> >  #include "core.h"
> >  #include "pinconf.h"
> > @@ -803,6 +804,7 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
> >       int div_clock = 0, ret, port, i, nbanks;
> >       struct device *dev = &pdev->dev;
> >       struct fwnode_handle *fwnode;
> > +     struct reset_control *reset;
> >       struct sgpio_priv *priv;
> >       struct clk *clk;
> >       u32 val;
> > @@ -813,6 +815,11 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
> >
> >       priv->dev = dev;
> >
> > +     reset = devm_reset_control_get_optional_shared(&pdev->dev, "switch");
> 
> This is the first GPIO driver that I am aware of that requests a named
> reset control, so I'm still not sure if this should be called "switch"
> instead of "gpio" or just "reset", just in case there is a future model
> where the GPIO controller reset is not shared with the switch reset.

I agree, it is not the best name. But the name "switch" was already used
in DT by sparx5[1], so I just went with this name.

> 
> > +     if (IS_ERR(reset))
> > +             return dev_err_probe(dev, PTR_ERR(reset), "Failed to get reset\n");
> > +     reset_control_reset(reset);
> > +
> >       clk = devm_clk_get(dev, NULL);
> >       if (IS_ERR(clk))
> >               return dev_err_probe(dev, PTR_ERR(clk), "Failed to get clock\n");
> 
> But whichever name you choose, the code is
> 
> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
> 
> regards
> Philipp

[1] https://elixir.bootlin.com/linux/v5.15-rc5/source/arch/arm64/boot/dts/microchip/sparx5.dtsi#L307
Philipp Zabel Oct. 18, 2021, 11:14 a.m. UTC | #3 
On Mon, 2021-10-18 at 13:12 +0200, Horatiu Vultur wrote:
> The 10/18/2021 12:37, Philipp Zabel wrote:
> 
> Hi Philipp,
> > Hi Horatiu,
> > 
> > On Mon, 2021-10-18 at 10:57 +0200, Horatiu Vultur wrote:
> > > On lan966x platform when the switch gets reseted then also the sgpio
> > > gets reseted. The fix for this is to extend also the sgpio driver to
> > > call the reset driver which will be reseted only once by the first
> > > driver that is probed.
> > > 
> > > Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> > > ---
> > >  drivers/pinctrl/pinctrl-microchip-sgpio.c | 7 +++++++
> > >  1 file changed, 7 insertions(+)
> > > 
> > > diff --git a/drivers/pinctrl/pinctrl-microchip-sgpio.c b/drivers/pinctrl/pinctrl-microchip-sgpio.c
> > > index 072bccdea2a5..78765faa245a 100644
> > > --- a/drivers/pinctrl/pinctrl-microchip-sgpio.c
> > > +++ b/drivers/pinctrl/pinctrl-microchip-sgpio.c
> > > @@ -17,6 +17,7 @@
> > >  #include <linux/pinctrl/pinmux.h>
> > >  #include <linux/platform_device.h>
> > >  #include <linux/property.h>
> > > +#include <linux/reset.h>
> > > 
> > >  #include "core.h"
> > >  #include "pinconf.h"
> > > @@ -803,6 +804,7 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
> > >       int div_clock = 0, ret, port, i, nbanks;
> > >       struct device *dev = &pdev->dev;
> > >       struct fwnode_handle *fwnode;
> > > +     struct reset_control *reset;
> > >       struct sgpio_priv *priv;
> > >       struct clk *clk;
> > >       u32 val;
> > > @@ -813,6 +815,11 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
> > > 
> > >       priv->dev = dev;
> > > 
> > > +     reset = devm_reset_control_get_optional_shared(&pdev->dev, "switch");
> > 
> > This is the first GPIO driver that I am aware of that requests a named
> > reset control, so I'm still not sure if this should be called "switch"
> > instead of "gpio" or just "reset", just in case there is a future model
> > where the GPIO controller reset is not shared with the switch reset.
> 
> I agree, it is not the best name. But the name "switch" was already used
> in DT by sparx5[1], so I just went with this name.

Oh, ok, in that case the decision already has been made.

regards
Philipp
Steen Hegelund Oct. 19, 2021, 7:05 a.m. UTC | #4 
On Mon, 2021-10-18 at 10:57 +0200, Horatiu Vultur wrote:
> On lan966x platform when the switch gets reseted then also the sgpio
> gets reseted. The fix for this is to extend also the sgpio driver to
> call the reset driver which will be reseted only once by the first
> driver that is probed.
> 
> Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>

Reviewed-by: Steen Hegelund <steen.hegelund@microchip.com>
Linus Walleij Oct. 24, 2021, 9:03 p.m. UTC | #5 
On Mon, Oct 18, 2021 at 10:56 AM Horatiu Vultur
<horatiu.vultur@microchip.com> wrote:

> v5->v6:
>  - fix warnings reported by 'make dtbs_check'
>  - add back the name of the reset line

Patch set v6 applied, thanks for working this out!

Yours,
Linus Walleij