usb: chipidea: Add support for NPCM

Add Nuvoton NPCM BMC SoCs support to USB ChipIdea driver.
NPCM SoC includes ChipIdea IP block that is used for USB device controller
mode.
Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Acked-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20231017195903.1665260-4-tmaimon77@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/chipidea/Kconfig

@@ -43,6 +43,10 @@ config USB_CHIPIDEA_MSM
 	tristate "Enable MSM hsusb glue driver" if EXPERT
 	default USB_CHIPIDEA
 
+config USB_CHIPIDEA_NPCM
+	tristate "Enable NPCM hsusb glue driver" if EXPERT
+	default USB_CHIPIDEA
+
 config USB_CHIPIDEA_IMX
 	tristate "Enable i.MX USB glue driver" if EXPERT
 	depends on OF

drivers/usb/chipidea/Makefile

@@ -13,6 +13,7 @@ ci_hdrc-$(CONFIG_USB_OTG_FSM)		+= otg_fsm.o
 
 obj-$(CONFIG_USB_CHIPIDEA_GENERIC)	+= ci_hdrc_usb2.o
 obj-$(CONFIG_USB_CHIPIDEA_MSM)		+= ci_hdrc_msm.o
+obj-$(CONFIG_USB_CHIPIDEA_NPCM)		+= ci_hdrc_npcm.o
 obj-$(CONFIG_USB_CHIPIDEA_PCI)		+= ci_hdrc_pci.o
 obj-$(CONFIG_USB_CHIPIDEA_IMX)		+= usbmisc_imx.o ci_hdrc_imx.o
 obj-$(CONFIG_USB_CHIPIDEA_TEGRA)	+= ci_hdrc_tegra.o

drivers/usb/chipidea/ci_hdrc_npcm.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2023 Nuvoton Technology corporation.
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/usb/chipidea.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/reset-controller.h>
+#include <linux/of.h>
+
+#include "ci.h"
+
+struct npcm_udc_data {
+	struct platform_device	*ci;
+	struct clk		*core_clk;
+	struct ci_hdrc_platform_data pdata;
+};
+
+static int npcm_udc_notify_event(struct ci_hdrc *ci, unsigned event)
+{
+	struct device *dev = ci->dev->parent;
+
+	switch (event) {
+	case CI_HDRC_CONTROLLER_RESET_EVENT:
+		/* clear all mode bits */
+		hw_write(ci, OP_USBMODE, 0xffffffff, 0x0);
+		break;
+	default:
+		dev_dbg(dev, "unknown ci_hdrc event (%d)\n",event);
+		break;
+	}
+
+	return 0;
+}
+
+static int npcm_udc_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct npcm_udc_data *ci;
+	struct platform_device *plat_ci;
+	struct device *dev = &pdev->dev;
+
+	ci = devm_kzalloc(&pdev->dev, sizeof(*ci), GFP_KERNEL);
+	if (!ci)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, ci);
+
+	ci->core_clk = devm_clk_get_optional(dev, NULL);
+	if (IS_ERR(ci->core_clk))
+		return PTR_ERR(ci->core_clk);
+
+	ret = clk_prepare_enable(ci->core_clk);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to enable the clock: %d\n", ret);
+
+	ci->pdata.name = dev_name(dev);
+	ci->pdata.capoffset = DEF_CAPOFFSET;
+	ci->pdata.flags	= CI_HDRC_REQUIRES_ALIGNED_DMA |
+		CI_HDRC_FORCE_VBUS_ACTIVE_ALWAYS;
+	ci->pdata.phy_mode = USBPHY_INTERFACE_MODE_UTMI;
+	ci->pdata.notify_event = npcm_udc_notify_event;
+
+	plat_ci = ci_hdrc_add_device(dev, pdev->resource, pdev->num_resources,
+				     &ci->pdata);
+	if (IS_ERR(plat_ci)) {
+		ret = PTR_ERR(plat_ci);
+		dev_err(dev, "failed to register HDRC NPCM device: %d\n", ret);
+		goto clk_err;
+	}
+
+	pm_runtime_no_callbacks(dev);
+	pm_runtime_enable(dev);
+
+	return 0;
+
+clk_err:
+	clk_disable_unprepare(ci->core_clk);
+	return ret;
+}
+
+static int npcm_udc_remove(struct platform_device *pdev)
+{
+	struct npcm_udc_data *ci = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(&pdev->dev);
+	ci_hdrc_remove_device(ci->ci);
+	clk_disable_unprepare(ci->core_clk);
+
+	return 0;
+}
+
+static const struct of_device_id npcm_udc_dt_match[] = {
+	{ .compatible = "nuvoton,npcm750-udc", },
+	{ .compatible = "nuvoton,npcm845-udc", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, npcm_udc_dt_match);
+
+static struct platform_driver npcm_udc_driver = {
+	.probe = npcm_udc_probe,
+	.remove = npcm_udc_remove,
+	.driver = {
+		.name = "npcm_udc",
+		.of_match_table = npcm_udc_dt_match,
+	},
+};
+
+module_platform_driver(npcm_udc_driver);
+
+MODULE_DESCRIPTION("NPCM USB device controller driver");
+MODULE_AUTHOR("Tomer Maimon <tomer.maimon@nuvoton.com>");
+MODULE_LICENSE("GPL v2");