usb: gadget: udc: Add Synopsys UDC Platform driver

This patch adds platform driver support for Synopsys UDC.

A new driver file (snps_udc_plat.c) is created for this purpose
where the platform driver registration is done based on OF
node.

Currently, UDC integrated into Broadcom's iProc SoCs (Northstar2
and Cygnus) work with this driver.

New members are added to the UDC data structure for having platform
device support along with extcon and phy support.

Kconfig and Makefiles are modified to select platform driver for
compilation.

Signed-off-by: Raviteja Garimella <raviteja.garimella@broadcom.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

1 files changed, 344 insertions, 0 deletions

diff --git a/drivers/usb/gadget/udc/snps_udc_plat.c b/drivers/usb/gadget/udc/snps_udc_plat.c
new file mode 100644
index 000000000000..2e11f19e07ae
--- /dev/null
+++ b/drivers/usb/gadget/udc/snps_udc_plat.c
@@ -0,0 +1,344 @@
+/*
+ * snps_udc_plat.c - Synopsys UDC Platform Driver
+ *
+ * Copyright (C) 2016 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/extcon.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/phy/phy.h>
+#include <linux/module.h>
+#include <linux/dmapool.h>
+#include <linux/interrupt.h>
+#include <linux/moduleparam.h>
+#include "amd5536udc.h"
+
+/* description */
+#define UDC_MOD_DESCRIPTION     "Synopsys UDC platform driver"
+
+void start_udc(struct udc *udc)
+{
+	if (udc->driver) {
+		dev_info(udc->dev, "Connecting...\n");
+		udc_enable_dev_setup_interrupts(udc);
+		udc_basic_init(udc);
+		udc->connected = 1;
+	}
+}
+
+void stop_udc(struct udc *udc)
+{
+	int tmp;
+	u32 reg;
+
+	spin_lock(&udc->lock);
+
+	/* Flush the receieve fifo */
+	reg = readl(&udc->regs->ctl);
+	reg |= AMD_BIT(UDC_DEVCTL_SRX_FLUSH);
+	writel(reg, &udc->regs->ctl);
+
+	reg = readl(&udc->regs->ctl);
+	reg &= ~(AMD_BIT(UDC_DEVCTL_SRX_FLUSH));
+	writel(reg, &udc->regs->ctl);
+	dev_dbg(udc->dev, "ep rx queue flushed\n");
+
+	/* Mask interrupts. Required more so when the
+	 * UDC is connected to a DRD phy.
+	 */
+	udc_mask_unused_interrupts(udc);
+
+	/* Disconnect gadget driver */
+	if (udc->driver) {
+		spin_unlock(&udc->lock);
+		udc->driver->disconnect(&udc->gadget);
+		spin_lock(&udc->lock);
+
+		/* empty queues */
+		for (tmp = 0; tmp < UDC_EP_NUM; tmp++)
+			empty_req_queue(&udc->ep[tmp]);
+	}
+	udc->connected = 0;
+
+	spin_unlock(&udc->lock);
+	dev_info(udc->dev, "Device disconnected\n");
+}
+
+void udc_drd_work(struct work_struct *work)
+{
+	struct udc *udc;
+
+	udc = container_of(to_delayed_work(work),
+			   struct udc, drd_work);
+
+	if (udc->conn_type) {
+		dev_dbg(udc->dev, "idle -> device\n");
+		start_udc(udc);
+	} else {
+		dev_dbg(udc->dev, "device -> idle\n");
+		stop_udc(udc);
+	}
+}
+
+static int usbd_connect_notify(struct notifier_block *self,
+			       unsigned long event, void *ptr)
+{
+	struct udc *udc = container_of(self, struct udc, nb);
+
+	dev_dbg(udc->dev, "%s: event: %lu\n", __func__, event);
+
+	udc->conn_type = event;
+
+	schedule_delayed_work(&udc->drd_work, 0);
+
+	return NOTIFY_OK;
+}
+
+static int udc_plat_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct udc *udc;
+	int ret;
+
+	udc = devm_kzalloc(dev, sizeof(*udc), GFP_KERNEL);
+	if (!udc)
+		return -ENOMEM;
+
+	spin_lock_init(&udc->lock);
+	udc->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	udc->virt_addr = devm_ioremap_resource(dev, res);
+	if (IS_ERR(udc->regs))
+		return PTR_ERR(udc->regs);
+
+	/* udc csr registers base */
+	udc->csr = udc->virt_addr + UDC_CSR_ADDR;
+
+	/* dev registers base */
+	udc->regs = udc->virt_addr + UDC_DEVCFG_ADDR;
+
+	/* ep registers base */
+	udc->ep_regs = udc->virt_addr + UDC_EPREGS_ADDR;
+
+	/* fifo's base */
+	udc->rxfifo = (u32 __iomem *)(udc->virt_addr + UDC_RXFIFO_ADDR);
+	udc->txfifo = (u32 __iomem *)(udc->virt_addr + UDC_TXFIFO_ADDR);
+
+	udc->phys_addr = (unsigned long)res->start;
+
+	udc->irq = irq_of_parse_and_map(dev->of_node, 0);
+	if (udc->irq <= 0) {
+		dev_err(dev, "Can't parse and map interrupt\n");
+		return -EINVAL;
+	}
+
+	udc->udc_phy = devm_of_phy_get_by_index(dev, dev->of_node, 0);
+	if (IS_ERR(udc->udc_phy)) {
+		dev_err(dev, "Failed to obtain phy from device tree\n");
+		return PTR_ERR(udc->udc_phy);
+	}
+
+	ret = phy_init(udc->udc_phy);
+	if (ret) {
+		dev_err(dev, "UDC phy init failed");
+		return ret;
+	}
+
+	ret = phy_power_on(udc->udc_phy);
+	if (ret) {
+		dev_err(dev, "UDC phy power on failed");
+		phy_exit(udc->udc_phy);
+		return ret;
+	}
+
+	/* Register for extcon if supported */
+	if (of_get_property(dev->of_node, "extcon", NULL)) {
+		udc->edev = extcon_get_edev_by_phandle(dev, 0);
+		if (IS_ERR(udc->edev)) {
+			if (PTR_ERR(udc->edev) == -EPROBE_DEFER)
+				return -EPROBE_DEFER;
+			dev_err(dev, "Invalid or missing extcon\n");
+			ret = PTR_ERR(udc->edev);
+			goto exit_phy;
+		}
+
+		udc->nb.notifier_call = usbd_connect_notify;
+		ret = extcon_register_notifier(udc->edev, EXTCON_USB,
+					       &udc->nb);
+		if (ret < 0) {
+			dev_err(dev, "Can't register extcon device\n");
+			goto exit_phy;
+		}
+
+		ret = extcon_get_cable_state_(udc->edev, EXTCON_USB);
+		if (ret < 0) {
+			dev_err(dev, "Can't get cable state\n");
+			goto exit_extcon;
+		} else if (ret) {
+			udc->conn_type = ret;
+		}
+		INIT_DELAYED_WORK(&udc->drd_work, udc_drd_work);
+	}
+
+	/* init dma pools */
+	if (use_dma) {
+		ret = init_dma_pools(udc);
+		if (ret != 0)
+			goto exit_extcon;
+	}
+
+	ret = devm_request_irq(dev, udc->irq, udc_irq, IRQF_SHARED,
+			       "snps-udc", udc);
+	if (ret < 0) {
+		dev_err(dev, "Request irq %d failed for UDC\n", udc->irq);
+		goto exit_dma;
+	}
+
+	platform_set_drvdata(pdev, udc);
+	udc->chiprev = UDC_BCM_REV;
+
+	if (udc_probe(udc)) {
+		ret = -ENODEV;
+		goto exit_dma;
+	}
+	dev_info(dev, "Synopsys UDC platform driver probe successful\n");
+
+	return 0;
+
+exit_dma:
+	if (use_dma)
+		free_dma_pools(udc);
+exit_extcon:
+	if (udc->edev)
+		extcon_unregister_notifier(udc->edev, EXTCON_USB, &udc->nb);
+exit_phy:
+	if (udc->udc_phy) {
+		phy_power_off(udc->udc_phy);
+		phy_exit(udc->udc_phy);
+	}
+	return ret;
+}
+
+static int udc_plat_remove(struct platform_device *pdev)
+{
+	struct udc *dev;
+
+	dev = platform_get_drvdata(pdev);
+
+	usb_del_gadget_udc(&dev->gadget);
+	/* gadget driver must not be registered */
+	if (WARN_ON(dev->driver))
+		return 0;
+
+	/* dma pool cleanup */
+	free_dma_pools(dev);
+
+	udc_remove(dev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	if (dev->drd_wq) {
+		flush_workqueue(dev->drd_wq);
+		destroy_workqueue(dev->drd_wq);
+	}
+
+	phy_power_off(dev->udc_phy);
+	phy_exit(dev->udc_phy);
+	extcon_unregister_notifier(dev->edev, EXTCON_USB, &dev->nb);
+
+	dev_info(&pdev->dev, "Synopsys UDC platform driver removed\n");
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int udc_plat_suspend(struct device *dev)
+{
+	struct udc *udc;
+
+	udc = dev_get_drvdata(dev);
+	stop_udc(udc);
+
+	if (extcon_get_cable_state_(udc->edev, EXTCON_USB) > 0) {
+		dev_dbg(udc->dev, "device -> idle\n");
+		stop_udc(udc);
+	}
+	phy_power_off(udc->udc_phy);
+	phy_exit(udc->udc_phy);
+
+	return 0;
+}
+
+static int udc_plat_resume(struct device *dev)
+{
+	struct udc *udc;
+	int ret;
+
+	udc = dev_get_drvdata(dev);
+
+	ret = phy_init(udc->udc_phy);
+	if (ret) {
+		dev_err(udc->dev, "UDC phy init failure");
+		return ret;
+	}
+
+	ret = phy_power_on(udc->udc_phy);
+	if (ret) {
+		dev_err(udc->dev, "UDC phy power on failure");
+		phy_exit(udc->udc_phy);
+		return ret;
+	}
+
+	if (extcon_get_cable_state_(udc->edev, EXTCON_USB) > 0) {
+		dev_dbg(udc->dev, "idle -> device\n");
+		start_udc(udc);
+	}
+
+	return 0;
+}
+static const struct dev_pm_ops udc_plat_pm_ops = {
+	.suspend	= udc_plat_suspend,
+	.resume		= udc_plat_resume,
+};
+#endif
+
+#if defined(CONFIG_OF)
+static const struct of_device_id of_udc_match[] = {
+	{ .compatible = "brcm,ns2-udc", },
+	{ .compatible = "brcm,cygnus-udc", },
+	{ .compatible = "brcm,iproc-udc", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, of_udc_match);
+#endif
+
+static struct platform_driver udc_plat_driver = {
+	.probe		= udc_plat_probe,
+	.remove		= udc_plat_remove,
+	.driver		= {
+		.name	= "snps-udc-plat",
+		.of_match_table = of_match_ptr(of_udc_match),
+#ifdef CONFIG_PM_SLEEP
+		.pm	= &udc_plat_pm_ops,
+#endif
+	},
+};
+module_platform_driver(udc_plat_driver);
+
+MODULE_DESCRIPTION(UDC_MOD_DESCRIPTION);
+MODULE_AUTHOR("Broadcom");
+MODULE_LICENSE("GPL v2");