RE: [PATCH v4 04/10] reset: renesas: Add RZ/G2L usbphy control driver

[Biju Das <biju.das.jz@bp.renesas.com>]

Hi All,

Gentle ping. Are we happy with this patch? Please let me know.

Regards,
Biju

> Subject: [PATCH v4 04/10] reset: renesas: Add RZ/G2L usbphy control driver
> 
> Add support for RZ/G2L USBPHY Control driver. It mainly controls reset and
> power down of the USB/PHY.
> 
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
> v3->v4:
>  * Incorporated the changes suggested by Philipp
>  * removed *dev pointer, replaced the magic number 0xff
>  * started using of_reset_simple_xlate
>  * Added spinlock for read-modify-writes
>  v3:
>   * New driver. As per Rob's suggestion, Modelled IP as a reset driver,
>     since it mainly controls reset and power down of the PHY.
> ---
>  drivers/reset/Kconfig                   |   7 +
>  drivers/reset/Makefile                  |   1 +
>  drivers/reset/reset-rzg2l-usbphy-ctrl.c | 175 ++++++++++++++++++++++++
>  3 files changed, 183 insertions(+)
>  create mode 100644 drivers/reset/reset-rzg2l-usbphy-ctrl.c
> 
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index
> 328f70f633eb..ed65ea66987b 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -181,6 +181,13 @@ config RESET_RASPBERRYPI
>  	  interfacing with RPi4's co-processor and model these firmware
>  	  initialization routines as reset lines.
> 
> +config RESET_RZG2L_USBPHY_CTRL
> +	tristate "Renesas RZ/G2L USBPHY control driver"
> +	depends on ARCH_R9A07G044 || COMPILE_TEST
> +	help
> +	  Support for USBPHY Control found on RZ/G2L family. It mainly
> +	  controls reset and power down of the USB/PHY.
> +
>  config RESET_SCMI
>  	tristate "Reset driver controlled via ARM SCMI interface"
>  	depends on ARM_SCMI_PROTOCOL || COMPILE_TEST diff --git
> a/drivers/reset/Makefile b/drivers/reset/Makefile index
> ea8b8d9ca565..21d46d8869ff 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -25,6 +25,7 @@ obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o
>  obj-$(CONFIG_RESET_QCOM_AOSS) += reset-qcom-aoss.o
>  obj-$(CONFIG_RESET_QCOM_PDC) += reset-qcom-pdc.o
>  obj-$(CONFIG_RESET_RASPBERRYPI) += reset-raspberrypi.o
> +obj-$(CONFIG_RESET_RZG2L_USBPHY_CTRL) += reset-rzg2l-usbphy-ctrl.o
>  obj-$(CONFIG_RESET_SCMI) += reset-scmi.o
>  obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o
>  obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o diff --git
> a/drivers/reset/reset-rzg2l-usbphy-ctrl.c b/drivers/reset/reset-rzg2l-
> usbphy-ctrl.c
> new file mode 100644
> index 000000000000..e0704fd2b533
> --- /dev/null
> +++ b/drivers/reset/reset-rzg2l-usbphy-ctrl.c
> @@ -0,0 +1,175 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Renesas RZ/G2L USBPHY control driver
> + *
> + * Copyright (C) 2021 Renesas Electronics Corporation  */
> +
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/reset.h>
> +#include <linux/reset-controller.h>
> +
> +#define RESET			0x000
> +
> +#define RESET_SEL_PLLRESET	BIT(12)
> +#define RESET_PLLRESET		BIT(8)
> +
> +#define RESET_SEL_P2RESET	BIT(5)
> +#define RESET_SEL_P1RESET	BIT(4)
> +#define RESET_PHYRST_2		BIT(1)
> +#define RESET_PHYRST_1		BIT(0)
> +
> +#define PHY_RESET_PORT2		(RESET_SEL_P2RESET | RESET_PHYRST_2)
> +#define PHY_RESET_PORT1		(RESET_SEL_P1RESET | RESET_PHYRST_1)
> +
> +#define NUM_PORTS		2
> +
> +struct rzg2l_usbphy_ctrl_priv {
> +	struct reset_controller_dev rcdev;
> +	struct reset_control *rstc;
> +	void __iomem *base;
> +
> +	spinlock_t lock;
> +};
> +
> +#define rcdev_to_priv(x)	container_of(x, struct
> rzg2l_usbphy_ctrl_priv, rcdev)
> +
> +static int rzg2l_usbphy_ctrl_assert(struct reset_controller_dev *rcdev,
> +				    unsigned long id)
> +{
> +	struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
> +	u32 port_mask = PHY_RESET_PORT1 | PHY_RESET_PORT2;
> +	void __iomem *base = priv->base;
> +	unsigned long flags;
> +	u32 val;
> +
> +	spin_lock_irqsave(&priv->lock, flags);
> +	val = readl(base + RESET);
> +	val |= id ? PHY_RESET_PORT2 : PHY_RESET_PORT1;
> +	if (port_mask == (val & port_mask))
> +		val |= RESET_PLLRESET;
> +	writel(val, base + RESET);
> +	spin_unlock_irqrestore(&priv->lock, flags);
> +
> +	return 0;
> +}
> +
> +static int rzg2l_usbphy_ctrl_deassert(struct reset_controller_dev *rcdev,
> +				      unsigned long id)
> +{
> +	struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
> +	void __iomem *base = priv->base;
> +	unsigned long flags;
> +	u32 val;
> +
> +	spin_lock_irqsave(&priv->lock, flags);
> +	val = readl(base + RESET);
> +
> +	val |= RESET_SEL_PLLRESET;
> +	val &= ~(RESET_PLLRESET | (id ? PHY_RESET_PORT2 : PHY_RESET_PORT1));
> +	writel(val, base + RESET);
> +	spin_unlock_irqrestore(&priv->lock, flags);
> +
> +	return 0;
> +}
> +
> +static int rzg2l_usbphy_ctrl_status(struct reset_controller_dev *rcdev,
> +				    unsigned long id)
> +{
> +	struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
> +	u32 port_mask;
> +
> +	port_mask = id ? PHY_RESET_PORT2 : PHY_RESET_PORT1;
> +
> +	return !!(readl(priv->base + RESET) & port_mask); }
> +
> +static const struct of_device_id rzg2l_usbphy_ctrl_match_table[] = {
> +	{ .compatible = "renesas,rzg2l-usbphy-ctrl" },
> +	{ /* Sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, rzg2l_usbphy_ctrl_match_table);
> +
> +static const struct reset_control_ops rzg2l_usbphy_ctrl_reset_ops = {
> +	.assert = rzg2l_usbphy_ctrl_assert,
> +	.deassert = rzg2l_usbphy_ctrl_deassert,
> +	.status = rzg2l_usbphy_ctrl_status,
> +};
> +
> +static int rzg2l_usbphy_ctrl_probe(struct platform_device *pdev) {
> +	struct device *dev = &pdev->dev;
> +	struct rzg2l_usbphy_ctrl_priv *priv;
> +	unsigned long flags;
> +	int error;
> +	u32 val;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(priv->base))
> +		return PTR_ERR(priv->base);
> +
> +	priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
> +	if (IS_ERR(priv->rstc))
> +		return dev_err_probe(dev, PTR_ERR(priv->rstc),
> +				     "failed to get reset\n");
> +
> +	reset_control_deassert(priv->rstc);
> +
> +	priv->rcdev.ops = &rzg2l_usbphy_ctrl_reset_ops;
> +	priv->rcdev.of_reset_n_cells = 1;
> +	priv->rcdev.nr_resets = NUM_PORTS;
> +	priv->rcdev.of_node = dev->of_node;
> +	priv->rcdev.dev = dev;
> +
> +	error = devm_reset_controller_register(dev, &priv->rcdev);
> +	if (error)
> +		return error;
> +
> +	spin_lock_init(&priv->lock);
> +	dev_set_drvdata(dev, priv);
> +
> +	pm_runtime_enable(&pdev->dev);
> +	pm_runtime_resume_and_get(&pdev->dev);
> +
> +	/* put pll and phy into reset state */
> +	spin_lock_irqsave(&priv->lock, flags);
> +	val = readl(priv->base + RESET);
> +	val |= RESET_SEL_PLLRESET | RESET_PLLRESET | PHY_RESET_PORT2 |
> PHY_RESET_PORT1;
> +	writel(val, priv->base + RESET);
> +	spin_unlock_irqrestore(&priv->lock, flags);
> +
> +	return 0;
> +}
> +
> +static int rzg2l_usbphy_ctrl_remove(struct platform_device *pdev) {
> +	struct rzg2l_usbphy_ctrl_priv *priv = dev_get_drvdata(&pdev->dev);
> +
> +	pm_runtime_put(&pdev->dev);
> +	pm_runtime_disable(&pdev->dev);
> +	reset_control_assert(priv->rstc);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver rzg2l_usbphy_ctrl_driver = {
> +	.driver = {
> +		.name		= "rzg2l_usbphy_ctrl",
> +		.of_match_table	= rzg2l_usbphy_ctrl_match_table,
> +	},
> +	.probe	= rzg2l_usbphy_ctrl_probe,
> +	.remove	= rzg2l_usbphy_ctrl_remove,
> +};
> +module_platform_driver(rzg2l_usbphy_ctrl_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Renesas RZ/G2L USBPHY Control");
> +MODULE_AUTHOR("biju.das.jz@bp.renesas.com>");
> --
> 2.17.1