[PATCH v3 0/3] RZ/G2L SCI support and sh-sci driver update

[PATCH v3 0/3] RZ/G2L SCI support and sh-sci driver update

[Lad Prabhakar]

Hi All,

This patch series updates binding doc to support RZ/G2L and
adds support to perform deassert/assert in sh-sci driver.

Cheers,
Prabhakar

V3:
* Fixed review comments pointed by Geert.

v2:
* https://patchwork.kernel.org/project/linux-renesas-soc/cover/
20211109121631.26687-1-prabhakar.mahadev-lad.rj@bp.renesas.com/

v1: https://patchwork.kernel.org/project/linux-renesas-soc/cover/
20211103173127.13701-1-prabhakar.mahadev-lad.rj@bp.renesas.com/

Lad Prabhakar (3):
  dt-bindings: serial: renesas,scif: Make resets as a required property
  dt-bindings: serial: renesas,sci: Document RZ/G2L SoC
  serial: sh-sci: Add support to deassert/assert reset line

 .../bindings/serial/renesas,sci.yaml          | 46 ++++++++++++++++---
 .../bindings/serial/renesas,scif.yaml         |  1 +
 drivers/tty/serial/sh-sci.c                   | 39 +++++++++++++---
 3 files changed, 73 insertions(+), 13 deletions(-)

-- 
2.17.1

[PATCH v3 1/3] dt-bindings: serial: renesas,scif: Make resets as a required property

[Lad Prabhakar]

Make "resets" as required property for RZ/G2L. On RZ/G2L the devices
should be explicitly pulled out of reset for this reason make "resets"
as required property.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v2->v3
* No Change
---
 Documentation/devicetree/bindings/serial/renesas,scif.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/serial/renesas,scif.yaml b/Documentation/devicetree/bindings/serial/renesas,scif.yaml
index 6b8731f7f2fb..21fbfa880e29 100644
--- a/Documentation/devicetree/bindings/serial/renesas,scif.yaml
+++ b/Documentation/devicetree/bindings/serial/renesas,scif.yaml
@@ -153,6 +153,7 @@ if:
         enum:
           - renesas,rcar-gen2-scif
           - renesas,rcar-gen3-scif
+          - renesas,scif-r9a07g044
 then:
   required:
     - resets
-- 
2.17.1

Re: [PATCH v3 1/3] dt-bindings: serial: renesas,scif: Make resets as a required property

[Rob Herring]

On Wed, 10 Nov 2021 23:29:18 +0000, Lad Prabhakar wrote:
> Make "resets" as required property for RZ/G2L. On RZ/G2L the devices
> should be explicitly pulled out of reset for this reason make "resets"
> as required property.
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> v2->v3
> * No Change
> ---
>  Documentation/devicetree/bindings/serial/renesas,scif.yaml | 1 +
>  1 file changed, 1 insertion(+)
> 

Acked-by: Rob Herring <robh@kernel.org>

[PATCH v3 2/3] dt-bindings: serial: renesas,sci: Document RZ/G2L SoC

[Lad Prabhakar]

Add SCI binding documentation for Renesas RZ/G2L SoC.

Also update the example node with RZ/G2L SCI0 node.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v2->v3
* Added const "renesas,sci" entry under items for h8300
---
 .../bindings/serial/renesas,sci.yaml          | 46 ++++++++++++++++---
 1 file changed, 40 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/serial/renesas,sci.yaml b/Documentation/devicetree/bindings/serial/renesas,sci.yaml
index 22ed2f0b1dc3..f00b1d38e9a5 100644
--- a/Documentation/devicetree/bindings/serial/renesas,sci.yaml
+++ b/Documentation/devicetree/bindings/serial/renesas,sci.yaml
@@ -14,7 +14,14 @@ allOf:
 
 properties:
   compatible:
-    const: renesas,sci
+    oneOf:
+      - items:
+          - enum:
+              - renesas,r9a07g044-sci     # RZ/G2{L,LC}
+          - const: renesas,sci            # generic SCI compatible UART
+
+      - items:
+          - const: renesas,sci            # generic SCI compatible UART
 
   reg:
     maxItems: 1
@@ -54,18 +61,45 @@ required:
   - clocks
   - clock-names
 
+if:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - renesas,r9a07g044-sci
+then:
+  properties:
+    resets:
+      maxItems: 1
+
+    power-domains:
+      maxItems: 1
+
+  required:
+    - resets
+    - power-domains
+
 unevaluatedProperties: false
 
 examples:
   - |
+    #include <dt-bindings/clock/r9a07g044-cpg.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
     aliases {
             serial0 = &sci0;
     };
 
-    sci0: serial@ffff78 {
-            compatible = "renesas,sci";
-            reg = <0xffff78 8>;
-            interrupts = <88 0>, <89 0>, <90 0>, <91 0>;
-            clocks = <&fclk>;
+    sci0: serial@1004d000 {
+            compatible = "renesas,r9a07g044-sci", "renesas,sci";
+            reg = <0x1004d000 0x400>;
+            interrupts = <GIC_SPI 405 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 406 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 407 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 408 IRQ_TYPE_LEVEL_HIGH>;
+            interrupt-names = "eri", "rxi", "txi", "tei";
+            clocks = <&cpg CPG_MOD R9A07G044_SCI0_CLKP>;
             clock-names = "fck";
+            power-domains = <&cpg>;
+            resets = <&cpg R9A07G044_SCI0_RST>;
     };
-- 
2.17.1

Re: [PATCH v3 2/3] dt-bindings: serial: renesas,sci: Document RZ/G2L SoC

[Rob Herring]

On Wed, 10 Nov 2021 23:29:19 +0000, Lad Prabhakar wrote:
> Add SCI binding documentation for Renesas RZ/G2L SoC.
> 
> Also update the example node with RZ/G2L SCI0 node.
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> v2->v3
> * Added const "renesas,sci" entry under items for h8300
> ---
>  .../bindings/serial/renesas,sci.yaml          | 46 ++++++++++++++++---
>  1 file changed, 40 insertions(+), 6 deletions(-)
> 

Acked-by: Rob Herring <robh@kernel.org>

[PATCH v3 3/3] serial: sh-sci: Add support to deassert/assert reset line

[Lad Prabhakar]

On RZ/G2L SoC we need to explicitly deassert the reset line
for the device to work, use this opportunity to deassert/assert
reset line in sh-sci driver.

This patch adds support to read the "resets" property (if available)
from DT and perform deassert/assert when required.

Also, propagate the error to the caller of sci_parse_dt() instead of
returning NULL in case of failure.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
---
v2->v3
* Dropped of_match_device
* Included RB tag
---
 drivers/tty/serial/sh-sci.c | 39 ++++++++++++++++++++++++++++++-------
 1 file changed, 32 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 89ee43061d3a..88005d2fc2a0 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -37,6 +37,7 @@
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 #include <linux/scatterlist.h>
 #include <linux/serial.h>
 #include <linux/serial_sci.h>
@@ -3203,23 +3204,47 @@ static const struct of_device_id of_sci_match[] = {
 };
 MODULE_DEVICE_TABLE(of, of_sci_match);
 
+static void sci_reset_control_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
 					  unsigned int *dev_id)
 {
 	struct device_node *np = pdev->dev.of_node;
+	struct reset_control *rstc;
 	struct plat_sci_port *p;
 	struct sci_port *sp;
 	const void *data;
-	int id;
+	int id, ret;
 
 	if (!IS_ENABLED(CONFIG_OF) || !np)
-		return NULL;
+		return ERR_PTR(-EINVAL);
 
 	data = of_device_get_match_data(&pdev->dev);
 
+	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(rstc))
+		return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
+					     "failed to get reset ctrl\n"));
+
+	ret = reset_control_deassert(rstc);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
+		return ERR_PTR(ret);
+	}
+
+	ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
+			ret);
+		return ERR_PTR(ret);
+	}
+
 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
 	if (!p)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	/* Get the line number from the aliases node. */
 	id = of_alias_get_id(np, "serial");
@@ -3227,11 +3252,11 @@ static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
 		id = ffz(sci_ports_in_use);
 	if (id < 0) {
 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	}
 	if (id >= ARRAY_SIZE(sci_ports)) {
 		dev_err(&pdev->dev, "serial%d out of range\n", id);
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	}
 
 	sp = &sci_ports[id];
@@ -3318,8 +3343,8 @@ static int sci_probe(struct platform_device *dev)
 
 	if (dev->dev.of_node) {
 		p = sci_parse_dt(dev, &dev_id);
-		if (p == NULL)
-			return -EINVAL;
+		if (IS_ERR(p))
+			return PTR_ERR(p);
 	} else {
 		p = dev->dev.platform_data;
 		if (p == NULL) {
-- 
2.17.1

Re: [PATCH v3 3/3] serial: sh-sci: Add support to deassert/assert reset line

[Geert Uytterhoeven]

On Thu, Nov 11, 2021 at 12:29 AM Lad Prabhakar
<prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:
> On RZ/G2L SoC we need to explicitly deassert the reset line
> for the device to work, use this opportunity to deassert/assert
> reset line in sh-sci driver.
>
> This patch adds support to read the "resets" property (if available)
> from DT and perform deassert/assert when required.
>
> Also, propagate the error to the caller of sci_parse_dt() instead of
> returning NULL in case of failure.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

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