[PATCH v3 0/2] Add support for nuvoton ma35 usb2 phy

[PATCH v3 0/2] Add support for nuvoton ma35 usb2 phy

[Hui-Ping Chen]

This patch series adds the usb2 phy driver for the nuvoton ma35 ARMv8 SoC.
It includes DT binding documentation and the ma35 usb2 phy driver.

v3:
  - Update nuvoton,ma35d1-usb2-phy.yaml
    - Update the syscon usage description.


v2:
  - Update nuvoton,ma35d1-usb2-phy.yaml
    - Update the 'nuvoton,ma35-usb2-phy' to 'nuvoton,ma35d1-usb2-phy'.
    - Remove unnecessary descriptions. 
    - Add explanations related to SYS.
  - Update ma35d1 usb2 phy driver
    - Update the 'nuvoton,ma35-usb2-phy' to 'nuvoton,ma35d1-usb2-phy'.
    - Use readl_poll_timeout() to make the system more efficient and the 
      code more streamlined.
    - Use the same variable name. Update the 'p_phy->dev' to 'pdev->dev'.


Hui-Ping Chen (2):
  dt-bindings: phy: nuvoton,ma35-usb2-phy: add new bindings
  phy: nuvoton: add new driver for the Nuvoton MA35 SoC USB 2.0 PHY

 .../bindings/phy/nuvoton,ma35d1-usb2-phy.yaml |  45 ++++++
 drivers/phy/Kconfig                           |   1 +
 drivers/phy/Makefile                          |   1 +
 drivers/phy/nuvoton/Kconfig                   |  13 ++
 drivers/phy/nuvoton/Makefile                  |   3 +
 drivers/phy/nuvoton/phy-ma35d1-usb2.c         | 146 ++++++++++++++++++
 6 files changed, 209 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/phy/nuvoton,ma35d1-usb2-phy.yaml
 create mode 100644 drivers/phy/nuvoton/Kconfig
 create mode 100644 drivers/phy/nuvoton/Makefile
 create mode 100644 drivers/phy/nuvoton/phy-ma35d1-usb2.c

-- 
2.25.1

[PATCH v3 1/2] dt-bindings: phy: nuvoton,ma35-usb2-phy: add new bindings

[Hui-Ping Chen]

Add dt-bindings for USB2 PHY found on the Nuvoton MA35 SoC.

Signed-off-by: Hui-Ping Chen <hpchen0nvt@gmail.com>
---
 .../bindings/phy/nuvoton,ma35d1-usb2-phy.yaml | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/phy/nuvoton,ma35d1-usb2-phy.yaml

diff --git a/Documentation/devicetree/bindings/phy/nuvoton,ma35d1-usb2-phy.yaml b/Documentation/devicetree/bindings/phy/nuvoton,ma35d1-usb2-phy.yaml
new file mode 100644
index 000000000000..fff858c909a0
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/nuvoton,ma35d1-usb2-phy.yaml
@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/nuvoton,ma35d1-usb2-phy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton MA35D1 USB2 phy
+
+maintainers:
+  - Hui-Ping Chen <hpchen0nvt@gmail.com>
+
+properties:
+  compatible:
+    enum:
+      - nuvoton,ma35d1-usb2-phy
+
+  "#phy-cells":
+    const: 0
+
+  clocks:
+    maxItems: 1
+
+  nuvoton,sys:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      phandle to syscon for checking the PHY clock status.
+
+required:
+  - compatible
+  - "#phy-cells"
+  - clocks
+  - nuvoton,sys
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/nuvoton,ma35d1-clk.h>
+
+    usb_phy: usb-phy {
+        compatible = "nuvoton,ma35d1-usb2-phy";
+        clocks = <&clk USBD_GATE>;
+        nuvoton,sys = <&sys>;
+        #phy-cells = <0>;
+    };
-- 
2.25.1

[PATCH v3 2/2] phy: nuvoton: add new driver for the Nuvoton MA35 SoC USB 2.0 PHY

[Hui-Ping Chen]

Nuvoton MA35 SoCs support DWC2 USB controller.
Add the driver to drive the USB 2.0 PHY transceivers.

Signed-off-by: Hui-Ping Chen <hpchen0nvt@gmail.com>
---
 drivers/phy/Kconfig                   |   1 +
 drivers/phy/Makefile                  |   1 +
 drivers/phy/nuvoton/Kconfig           |  13 +++
 drivers/phy/nuvoton/Makefile          |   3 +
 drivers/phy/nuvoton/phy-ma35d1-usb2.c | 146 ++++++++++++++++++++++++++
 5 files changed, 164 insertions(+)
 create mode 100644 drivers/phy/nuvoton/Kconfig
 create mode 100644 drivers/phy/nuvoton/Makefile
 create mode 100644 drivers/phy/nuvoton/phy-ma35d1-usb2.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index dfab1c66b3e5..f73abff416be 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -95,6 +95,7 @@ source "drivers/phy/mediatek/Kconfig"
 source "drivers/phy/microchip/Kconfig"
 source "drivers/phy/motorola/Kconfig"
 source "drivers/phy/mscc/Kconfig"
+source "drivers/phy/nuvoton/Kconfig"
 source "drivers/phy/qualcomm/Kconfig"
 source "drivers/phy/ralink/Kconfig"
 source "drivers/phy/realtek/Kconfig"
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 5fcbce5f9ab1..ebc399560da4 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -25,6 +25,7 @@ obj-y					+= allwinner/	\
 					   microchip/	\
 					   motorola/	\
 					   mscc/	\
+					   nuvoton/	\
 					   qualcomm/	\
 					   ralink/	\
 					   realtek/	\
diff --git a/drivers/phy/nuvoton/Kconfig b/drivers/phy/nuvoton/Kconfig
new file mode 100644
index 000000000000..270ee2943287
--- /dev/null
+++ b/drivers/phy/nuvoton/Kconfig
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# PHY drivers for Nuvoton MA35 platforms
+#
+config PHY_MA35_USB
+	tristate "Nuvoton MA35 USB2.0 PHY driver"
+	depends on ARCH_MA35 || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Enable this to support the USB2.0 PHY on the Nuvoton MA35
+	  series SoCs.
+
diff --git a/drivers/phy/nuvoton/Makefile b/drivers/phy/nuvoton/Makefile
new file mode 100644
index 000000000000..2937e3921898
--- /dev/null
+++ b/drivers/phy/nuvoton/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_PHY_MA35_USB)		+= phy-ma35d1-usb2.o
diff --git a/drivers/phy/nuvoton/phy-ma35d1-usb2.c b/drivers/phy/nuvoton/phy-ma35d1-usb2.c
new file mode 100644
index 000000000000..8922e5da8e3b
--- /dev/null
+++ b/drivers/phy/nuvoton/phy-ma35d1-usb2.c
@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+/* USB PHY Miscellaneous Control Register */
+#define MA35_SYS_REG_USBPMISCR	0x60
+#define PHY0POR			BIT(0)  /* PHY Power-On Reset Control Bit */
+#define PHY0SUSPEND			BIT(1)  /* PHY Suspend; 0: suspend, 1: operaion */
+#define PHY0COMN			BIT(2)  /* PHY Common Block Power-Down Control */
+#define PHY0DEVCKSTB			BIT(10) /* PHY 60 MHz UTMI clock stable bit */
+
+struct ma35_usb_phy {
+	struct clk *clk;
+	struct device *dev;
+	struct regmap *sysreg;
+};
+
+static int ma35_usb_phy_power_on(struct phy *phy)
+{
+	struct ma35_usb_phy *p_phy = phy_get_drvdata(phy);
+	unsigned int val;
+	int ret;
+
+	ret = clk_prepare_enable(p_phy->clk);
+	if (ret < 0) {
+		dev_err(p_phy->dev, "Failed to enable PHY clock: %d\n", ret);
+		return ret;
+	}
+
+	regmap_read(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, &val);
+	if (val & PHY0SUSPEND) {
+		/*
+		 * USB PHY0 is in operation mode already
+		 * make sure USB PHY 60 MHz UTMI Interface Clock ready
+		 */
+		ret = readl_poll_timeout((void __iomem *)p_phy->sysreg + MA35_SYS_REG_USBPMISCR,
+					 val, val & PHY0DEVCKSTB, 1, 100);
+		if (ret == -ETIMEDOUT) {
+			dev_err(p_phy->dev, "1.Check PHY clock, Timeout: %d\n", val);
+			return ret;
+		}
+		return 0;
+	}
+
+	/*
+	 * reset USB PHY0.
+	 * wait until USB PHY0 60 MHz UTMI Interface Clock ready
+	 */
+	regmap_update_bits(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, 0x7, (PHY0POR | PHY0SUSPEND));
+	udelay(10);
+
+	/* make USB PHY0 enter operation mode */
+	regmap_update_bits(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, 0x7, PHY0SUSPEND);
+
+	/* make sure USB PHY 60 MHz UTMI Interface Clock ready */
+	ret = readl_poll_timeout((void __iomem *)p_phy->sysreg + MA35_SYS_REG_USBPMISCR,
+				 val, val & PHY0DEVCKSTB, 1, 100);
+	if (ret == -ETIMEDOUT) {
+		dev_err(p_phy->dev, "2.Check PHY clock, Timeout: %d\n", ret);
+		return ret;
+	}
+
+	clk_disable_unprepare(p_phy->clk);
+	return 0;
+}
+
+static int ma35_usb_phy_power_off(struct phy *phy)
+{
+	struct ma35_usb_phy *p_phy = phy_get_drvdata(phy);
+
+	clk_disable_unprepare(p_phy->clk);
+	return 0;
+}
+
+static const struct phy_ops ma35_usb_phy_ops = {
+	.power_on = ma35_usb_phy_power_on,
+	.power_off = ma35_usb_phy_power_off,
+	.owner = THIS_MODULE,
+};
+
+static int ma35_usb_phy_probe(struct platform_device *pdev)
+{
+	struct phy_provider *provider;
+	struct ma35_usb_phy *p_phy;
+	struct phy *phy;
+
+	p_phy = devm_kzalloc(&pdev->dev, sizeof(*p_phy), GFP_KERNEL);
+	if (!p_phy)
+		return -ENOMEM;
+
+	p_phy->dev = &pdev->dev;
+	platform_set_drvdata(pdev, p_phy);
+
+	p_phy->sysreg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "nuvoton,sys");
+	if (IS_ERR(p_phy->sysreg))
+		return dev_err_probe(&pdev->dev, PTR_ERR(p_phy->sysreg),
+				     "Failed to get SYS registers\n");
+
+	p_phy->clk = of_clk_get(pdev->dev.of_node, 0);
+	if (IS_ERR(p_phy->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(p_phy->clk),
+				     "failed to find usb_phy clock\n");
+
+	phy = devm_phy_create(&pdev->dev, NULL, &ma35_usb_phy_ops);
+	if (IS_ERR(phy))
+		return dev_err_probe(&pdev->dev, PTR_ERR(phy), "Failed to create PHY\n");
+
+	phy_set_drvdata(phy, p_phy);
+
+	provider = devm_of_phy_provider_register(&pdev->dev, of_phy_simple_xlate);
+	if (IS_ERR(provider))
+		return dev_err_probe(&pdev->dev, PTR_ERR(provider),
+				     "Failed to register PHY provider\n");
+	return 0;
+}
+
+static const struct of_device_id ma35_usb_phy_of_match[] = {
+	{ .compatible = "nuvoton,ma35d1-usb2-phy", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ma35_usb_phy_of_match);
+
+static struct platform_driver ma35_usb_phy_driver = {
+	.probe		= ma35_usb_phy_probe,
+	.driver	= {
+		.name	= "ma35d1-usb2-phy",
+		.of_match_table = ma35_usb_phy_of_match,
+	},
+};
+module_platform_driver(ma35_usb_phy_driver);
+
+MODULE_DESCRIPTION("Nuvoton ma35d1 USB2.0 PHY driver");
+MODULE_AUTHOR("hpchen0nvt@gmail.com");
+MODULE_LICENSE("GPL");
-- 
2.25.1

Re: [PATCH v3 2/2] phy: nuvoton: add new driver for the Nuvoton MA35 SoC USB 2.0 PHY

[Markus Elfring]

…
> +++ b/drivers/phy/nuvoton/phy-ma35d1-usb2.c
> @@ -0,0 +1,146 @@
…
> +MODULE_DESCRIPTION("Nuvoton ma35d1 USB2.0 PHY driver");
> +MODULE_AUTHOR("hpchen0nvt@gmail.com");
…

How do you think about to add a personal name to such an email address?

Regards,
Markus

Re: [PATCH v3 1/2] dt-bindings: phy: nuvoton,ma35-usb2-phy: add new bindings

[Krzysztof Kozlowski]

On 01/08/2024 07:37, Hui-Ping Chen wrote:
> Add dt-bindings for USB2 PHY found on the Nuvoton MA35 SoC.
> 
> Signed-off-by: Hui-Ping Chen <hpchen0nvt@gmail.com>
> ---

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

Best regards,
Krzysztof

Re: [PATCH v3 2/2] phy: nuvoton: add new driver for the Nuvoton MA35 SoC USB 2.0 PHY

[Krzysztof Kozlowski]

On 01/08/2024 07:37, Hui-Ping Chen wrote:
> +	struct regmap *sysreg;

Look here - iomem? No.

> +};
> +
> +static int ma35_usb_phy_power_on(struct phy *phy)
> +{
> +	struct ma35_usb_phy *p_phy = phy_get_drvdata(phy);
> +	unsigned int val;
> +	int ret;
> +
> +	ret = clk_prepare_enable(p_phy->clk);
> +	if (ret < 0) {
> +		dev_err(p_phy->dev, "Failed to enable PHY clock: %d\n", ret);
> +		return ret;
> +	}
> +
> +	regmap_read(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, &val);
> +	if (val & PHY0SUSPEND) {
> +		/*
> +		 * USB PHY0 is in operation mode already
> +		 * make sure USB PHY 60 MHz UTMI Interface Clock ready
> +		 */
> +		ret = readl_poll_timeout((void __iomem *)p_phy->sysreg + MA35_SYS_REG_USBPMISCR,

Eh, I responded to v2, not here, so repeating:

sysreg is a regmap, not io address. How could it possibly work and be
tested?!? This cannot work. Test your code *before* sending it.


Best regards,
Krzysztof

Re: [PATCH v3 2/2] phy: nuvoton: add new driver for the Nuvoton MA35 SoC USB 2.0 PHY

[Hui-Ping Chen]

Dear Markus,

Thank you for your reply.



On 2024/8/1 下午 05:50, Markus Elfring wrote:
> …
>> +++ b/drivers/phy/nuvoton/phy-ma35d1-usb2.c
>> @@ -0,0 +1,146 @@
> …
>> +MODULE_DESCRIPTION("Nuvoton ma35d1 USB2.0 PHY driver");
>> +MODULE_AUTHOR("hpchen0nvt@gmail.com");
> …
>
> How do you think about to add a personal name to such an email address?

I'm sorry. I forgot to put my name here. I'll make it up.


> Regards,
> Markus


Best regards,

Hui-Ping Chen

Re: [PATCH v3 2/2] phy: nuvoton: add new driver for the Nuvoton MA35 SoC USB 2.0 PHY

[Hui-Ping Chen]

Dear Krzysztof,

Thank you for your reply.



On 2024/8/1 下午 10:43, Krzysztof Kozlowski wrote:
> On 01/08/2024 07:37, Hui-Ping Chen wrote:
>> +	struct regmap *sysreg;
> Look here - iomem? No.

Yes, this is my mistake.



>> +};
>> +
>> +static int ma35_usb_phy_power_on(struct phy *phy)
>> +{
>> +	struct ma35_usb_phy *p_phy = phy_get_drvdata(phy);
>> +	unsigned int val;
>> +	int ret;
>> +
>> +	ret = clk_prepare_enable(p_phy->clk);
>> +	if (ret < 0) {
>> +		dev_err(p_phy->dev, "Failed to enable PHY clock: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	regmap_read(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, &val);
>> +	if (val & PHY0SUSPEND) {
>> +		/*
>> +		 * USB PHY0 is in operation mode already
>> +		 * make sure USB PHY 60 MHz UTMI Interface Clock ready
>> +		 */
>> +		ret = readl_poll_timeout((void __iomem *)p_phy->sysreg + MA35_SYS_REG_USBPMISCR,
> Eh, I responded to v2, not here, so repeating:
>
> sysreg is a regmap, not io address. How could it possibly work and be
> tested?!? This cannot work. Test your code *before* sending it.
>
Yes, this is my mistake. I won't reply to v2. I will reply here.


I would change 'readl_poll_timeout' to 'regmap_read_poll_timeout'.

And it has been tested OK on our platform.



> Best regards,
> Krzysztof


Best regards,

Hui-Ping Chen