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@xxxxxxxxxxxxxx>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxxxx>");
--
2.17.1
