[PATCH 0/2] KingFisher: support regulators for PCIe

[PATCH 0/2] KingFisher: support regulators for PCIe

[Wolfram Sang]

Here are the patches to make PCIe cards work in the slot CN15 on a
KingFisher board. Look at the patches for a changelog, please.

   Wolfram

Wolfram Sang (2):
  dt-bindings: PCI: rcar-pci-host: add optional regulators
  PCI: rcar-host: add support for optional regulators

 .../devicetree/bindings/pci/rcar-pci-host.yaml    | 11 +++++++++++
 drivers/pci/controller/pcie-rcar-host.c           | 15 ++++++++++++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

-- 
2.30.2

[PATCH 1/2] dt-bindings: PCI: rcar-pci-host: add optional regulators

[Wolfram Sang]

Support regulators found on the e.g. KingFisher board for miniPCIe and
add a 12v regulator while we are here.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

Changes since RFC:
* added 12V supply for completeness
* use PCIe slot in the example instead of miniPCIe because that is what
  the Koelsch board offers (just without the regulators ;))

 .../devicetree/bindings/pci/rcar-pci-host.yaml        | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/pci/rcar-pci-host.yaml b/Documentation/devicetree/bindings/pci/rcar-pci-host.yaml
index 8fdfbc763d70..b6a7cb32f61e 100644
--- a/Documentation/devicetree/bindings/pci/rcar-pci-host.yaml
+++ b/Documentation/devicetree/bindings/pci/rcar-pci-host.yaml
@@ -68,6 +68,15 @@ properties:
   phy-names:
     const: pcie
 
+  vpcie1v5-supply:
+    description: The 1.5v regulator to use for PCIe.
+
+  vpcie3v3-supply:
+    description: The 3.3v regulator to use for PCIe.
+
+  vpcie12v-supply:
+    description: The 12v regulator to use for PCIe.
+
 required:
   - compatible
   - reg
@@ -121,5 +130,7 @@ examples:
              clock-names = "pcie", "pcie_bus";
              power-domains = <&sysc R8A7791_PD_ALWAYS_ON>;
              resets = <&cpg 319>;
+             vpcie3v3-supply = <&pcie_3v3>;
+             vpcie12v-supply = <&pcie_12v>;
          };
     };
-- 
2.30.2

Re: [PATCH 1/2] dt-bindings: PCI: rcar-pci-host: add optional regulators

[Geert Uytterhoeven]

On Wed, May 10, 2023 at 8:59 AM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> Support regulators found on the e.g. KingFisher board for miniPCIe and
> add a 12v regulator while we are here.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>
> Changes since RFC:
> * added 12V supply for completeness
> * use PCIe slot in the example instead of miniPCIe because that is what
>   the Koelsch board offers (just without the regulators ;))

Same for e.g. Salvator-XS.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 1/2] dt-bindings: PCI: rcar-pci-host: add optional regulators

[Krzysztof Kozlowski]

On 10/05/2023 08:58, Wolfram Sang wrote:
> Support regulators found on the e.g. KingFisher board for miniPCIe and
> add a 12v regulator while we are here.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
> 
> Changes since RFC:
> * added 12V supply for completeness
> * use PCIe slot in the example instead of miniPCIe because that is what
>   the Koelsch board offers (just without the regulators ;))
> 
>  .../devicetree/bindings/pci/rcar-pci-host.yaml        | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pci/rcar-pci-host.yaml

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH 2/2] PCI: rcar-host: add support for optional regulators

[Wolfram Sang]

The KingFisher board has regulators. They just need to be en-/disabled,
so we can leave the handling to devm.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

Changes since RFC:
* add 12v regulator
* add comment about the order of enabling the regulators
* use a for-loop to iterate over the regulators

Sidenote: I tried to introduce 'devm_regulator_bulk_get_enable_optional'
to avoid the for-loop but that was a too intrusive change because all of
the regulator_bulk logic is designed to fail if something bad happens
somewhere.

 drivers/pci/controller/pcie-rcar-host.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pcie-rcar-host.c b/drivers/pci/controller/pcie-rcar-host.c
index e80e56b2a842..e86bf0f7729b 100644
--- a/drivers/pci/controller/pcie-rcar-host.c
+++ b/drivers/pci/controller/pcie-rcar-host.c
@@ -29,6 +29,7 @@
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
 
 #include "pcie-rcar.h"
 
@@ -974,13 +975,18 @@ static const struct of_device_id rcar_pcie_of_match[] = {
 	{},
 };
 
+/* Design note 346 from Linear Technology says order is not important */
+static const char * const rcar_pcie_supplies[] = {
+	"vpcie12v", "vpcie3v3", "vpcie1v5"
+};
+
 static int rcar_pcie_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct rcar_pcie_host *host;
 	struct rcar_pcie *pcie;
 	u32 data;
-	int err;
+	int i, err;
 	struct pci_host_bridge *bridge;
 
 	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*host));
@@ -992,6 +998,13 @@ static int rcar_pcie_probe(struct platform_device *pdev)
 	pcie->dev = dev;
 	platform_set_drvdata(pdev, host);
 
+	for (i = 0; i < ARRAY_SIZE(rcar_pcie_supplies); i++) {
+		err = devm_regulator_get_enable_optional(dev, rcar_pcie_supplies[i]);
+		if (err < 0 && err != -ENODEV)
+			dev_err_probe(dev, err, "error enabling regulator %s\n",
+				      rcar_pcie_supplies[i]);
+	}
+
 	pm_runtime_enable(pcie->dev);
 	err = pm_runtime_get_sync(pcie->dev);
 	if (err < 0) {
-- 
2.30.2

Re: [PATCH 2/2] PCI: rcar-host: add support for optional regulators

[Geert Uytterhoeven]

Hi Wolfram,

On Wed, May 10, 2023 at 8:59 AM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> The KingFisher board has regulators. They just need to be en-/disabled,
> so we can leave the handling to devm.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>
> Changes since RFC:
> * add 12v regulator
> * add comment about the order of enabling the regulators
> * use a for-loop to iterate over the regulators

Thanks for the update!

> --- a/drivers/pci/controller/pcie-rcar-host.c
> +++ b/drivers/pci/controller/pcie-rcar-host.c
> @@ -29,6 +29,7 @@
>  #include <linux/phy/phy.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/regulator/consumer.h>
>
>  #include "pcie-rcar.h"
>
> @@ -974,13 +975,18 @@ static const struct of_device_id rcar_pcie_of_match[] = {
>         {},
>  };
>
> +/* Design note 346 from Linear Technology says order is not important */
> +static const char * const rcar_pcie_supplies[] = {
> +       "vpcie12v", "vpcie3v3", "vpcie1v5"
> +};
> +
>  static int rcar_pcie_probe(struct platform_device *pdev)
>  {
>         struct device *dev = &pdev->dev;
>         struct rcar_pcie_host *host;
>         struct rcar_pcie *pcie;
>         u32 data;
> -       int err;
> +       int i, err;

unsigned int i?

>         struct pci_host_bridge *bridge;

The (lack of) reverse-Xmas-tree ordering is hurting my OCD, but that's
not your fault...

> @@ -992,6 +998,13 @@ static int rcar_pcie_probe(struct platform_device *pdev)
>         pcie->dev = dev;
>         platform_set_drvdata(pdev, host);
>
> +       for (i = 0; i < ARRAY_SIZE(rcar_pcie_supplies); i++) {
> +               err = devm_regulator_get_enable_optional(dev, rcar_pcie_supplies[i]);
> +               if (err < 0 && err != -ENODEV)
> +                       dev_err_probe(dev, err, "error enabling regulator %s\n",
> +                                     rcar_pcie_supplies[i]);

Shouldn't this return, and propagate the error code upstream?

> +       }
> +
>         pm_runtime_enable(pcie->dev);
>         err = pm_runtime_get_sync(pcie->dev);
>         if (err < 0) {

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 2/2] PCI: rcar-host: add support for optional regulators

[Wolfram Sang]

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> > +       int i, err;
> 
> unsigned int i?

OK.

> 
> >         struct pci_host_bridge *bridge;
> 
> The (lack of) reverse-Xmas-tree ordering is hurting my OCD, but that's
> not your fault...

Ack :) I can change it, though.

> > +                       dev_err_probe(dev, err, "error enabling regulator %s\n",
> > +                                     rcar_pcie_supplies[i]);
> 
> Shouldn't this return, and propagate the error code upstream?

Ouch, brown paper bag, please.


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Re: [PATCH 2/2] PCI: rcar-host: add support for optional regulators

[Bjorn Helgaas]

On Wed, May 10, 2023 at 09:27:46AM +0200, Geert Uytterhoeven wrote:
> On Wed, May 10, 2023 at 8:59 AM Wolfram Sang
> <wsa+renesas@sang-engineering.com> wrote:
> ...

> >  static int rcar_pcie_probe(struct platform_device *pdev)
> >  {
> >         struct device *dev = &pdev->dev;
> >         struct rcar_pcie_host *host;
> >         struct rcar_pcie *pcie;
> >         u32 data;
> > -       int err;
> > +       int i, err;
> 
> unsigned int i?
> 
> >         struct pci_host_bridge *bridge;
> 
> The (lack of) reverse-Xmas-tree ordering is hurting my OCD, but that's
> not your fault...

I usually put things in order of use, with initializations from
parameters first.  Happily, that is often a pretty good approximation
of reverse-Xmas-tree, as it is here, so I'm all in favor of moving
"struct pci_host_bridge" up there :)

Bjorn