usb: host: Add EHCI driver for NVIDIA Tegra SoCs

The Tegra 2 SoC has 3 EHCI compatible USB controllers. This patch adds
the necessary glue to allow the ehci-hcd driver to work on Tegra 2
SoCs.

The platform data is used to configure board-specific phy settings and
to configure the operating mode, as one of the ports may be used as a otg
port. For additional power saving, the driver supports powering down the
phy on bus suspend when it is used, for example, to connect an internal
device that use an out-of-band remote wakeup mechanism (e.g. a gpio).

Signed-off-by: Benoit Goby <benoit@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 625 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-tegra.c b/drivers/usb/host/ehci-tegra.c
new file mode 100644
index 000000000000..6202102a6d75
--- /dev/null
+++ b/drivers/usb/host/ehci-tegra.c
@@ -0,0 +1,625 @@
+/*
+ * EHCI-compliant USB host controller driver for NVIDIA Tegra SoCs
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Copyright (C) 2009 NVIDIA Corporation
+ *
+ * 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; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/tegra_usb.h>
+#include <linux/irq.h>
+#include <linux/usb/otg.h>
+#include <mach/usb_phy.h>
+
+struct tegra_ehci_hcd {
+	struct ehci_hcd *ehci;
+	struct tegra_usb_phy *phy;
+	struct clk *clk;
+	struct clk *emc_clk;
+	struct otg_transceiver *transceiver;
+	int host_resumed;
+	int bus_suspended;
+	int port_resuming;
+	int power_down_on_bus_suspend;
+	enum tegra_usb_phy_port_speed port_speed;
+};
+
+static void tegra_ehci_power_up(struct usb_hcd *hcd)
+{
+	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
+
+	clk_enable(tegra->emc_clk);
+	clk_enable(tegra->clk);
+	tegra_usb_phy_power_on(tegra->phy);
+	tegra->host_resumed = 1;
+}
+
+static void tegra_ehci_power_down(struct usb_hcd *hcd)
+{
+	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
+
+	tegra->host_resumed = 0;
+	tegra_usb_phy_power_off(tegra->phy);
+	clk_disable(tegra->clk);
+	clk_disable(tegra->emc_clk);
+}
+
+static int tegra_ehci_hub_control(
+	struct usb_hcd	*hcd,
+	u16		typeReq,
+	u16		wValue,
+	u16		wIndex,
+	char		*buf,
+	u16		wLength
+)
+{
+	struct ehci_hcd	*ehci = hcd_to_ehci(hcd);
+	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
+	u32 __iomem	*status_reg;
+	u32		temp;
+	unsigned long	flags;
+	int		retval = 0;
+
+	status_reg = &ehci->regs->port_status[(wIndex & 0xff) - 1];
+
+	spin_lock_irqsave(&ehci->lock, flags);
+
+	/*
+	 * In ehci_hub_control() for USB_PORT_FEAT_ENABLE clears the other bits
+	 * that are write on clear, by writing back the register read value, so
+	 * USB_PORT_FEAT_ENABLE is handled by masking the set on clear bits
+	 */
+	if (typeReq == ClearPortFeature && wValue == USB_PORT_FEAT_ENABLE) {
+		temp = ehci_readl(ehci, status_reg) & ~PORT_RWC_BITS;
+		ehci_writel(ehci, temp & ~PORT_PE, status_reg);
+		goto done;
+	}
+
+	else if (typeReq == GetPortStatus) {
+		temp = ehci_readl(ehci, status_reg);
+		if (tegra->port_resuming && !(temp & PORT_SUSPEND)) {
+			/* Resume completed, re-enable disconnect detection */
+			tegra->port_resuming = 0;
+			tegra_usb_phy_postresume(tegra->phy);
+		}
+	}
+
+	else if (typeReq == SetPortFeature && wValue == USB_PORT_FEAT_SUSPEND) {
+		temp = ehci_readl(ehci, status_reg);
+		if ((temp & PORT_PE) == 0 || (temp & PORT_RESET) != 0) {
+			retval = -EPIPE;
+			goto done;
+		}
+
+		temp &= ~PORT_WKCONN_E;
+		temp |= PORT_WKDISC_E | PORT_WKOC_E;
+		ehci_writel(ehci, temp | PORT_SUSPEND, status_reg);
+
+		/*
+		 * If a transaction is in progress, there may be a delay in
+		 * suspending the port. Poll until the port is suspended.
+		 */
+		if (handshake(ehci, status_reg, PORT_SUSPEND,
+						PORT_SUSPEND, 5000))
+			pr_err("%s: timeout waiting for SUSPEND\n", __func__);
+
+		set_bit((wIndex & 0xff) - 1, &ehci->suspended_ports);
+		goto done;
+	}
+
+	/*
+	 * Tegra host controller will time the resume operation to clear the bit
+	 * when the port control state switches to HS or FS Idle. This behavior
+	 * is different from EHCI where the host controller driver is required
+	 * to set this bit to a zero after the resume duration is timed in the
+	 * driver.
+	 */
+	else if (typeReq == ClearPortFeature &&
+					wValue == USB_PORT_FEAT_SUSPEND) {
+		temp = ehci_readl(ehci, status_reg);
+		if ((temp & PORT_RESET) || !(temp & PORT_PE)) {
+			retval = -EPIPE;
+			goto done;
+		}
+
+		if (!(temp & PORT_SUSPEND))
+			goto done;
+
+		/* Disable disconnect detection during port resume */
+		tegra_usb_phy_preresume(tegra->phy);
+
+		ehci->reset_done[wIndex-1] = jiffies + msecs_to_jiffies(25);
+
+		temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
+		/* start resume signalling */
+		ehci_writel(ehci, temp | PORT_RESUME, status_reg);
+
+		spin_unlock_irqrestore(&ehci->lock, flags);
+		msleep(20);
+		spin_lock_irqsave(&ehci->lock, flags);
+
+		/* Poll until the controller clears RESUME and SUSPEND */
+		if (handshake(ehci, status_reg, PORT_RESUME, 0, 2000))
+			pr_err("%s: timeout waiting for RESUME\n", __func__);
+		if (handshake(ehci, status_reg, PORT_SUSPEND, 0, 2000))
+			pr_err("%s: timeout waiting for SUSPEND\n", __func__);
+
+		ehci->reset_done[wIndex-1] = 0;
+
+		tegra->port_resuming = 1;
+		goto done;
+	}
+
+	spin_unlock_irqrestore(&ehci->lock, flags);
+
+	/* Handle the hub control events here */
+	return ehci_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength);
+done:
+	spin_unlock_irqrestore(&ehci->lock, flags);
+	return retval;
+}
+
+static void tegra_ehci_restart(struct usb_hcd *hcd)
+{
+	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+
+	ehci_reset(ehci);
+
+	/* setup the frame list and Async q heads */
+	ehci_writel(ehci, ehci->periodic_dma, &ehci->regs->frame_list);
+	ehci_writel(ehci, (u32)ehci->async->qh_dma, &ehci->regs->async_next);
+	/* setup the command register and set the controller in RUN mode */
+	ehci->command &= ~(CMD_LRESET|CMD_IAAD|CMD_PSE|CMD_ASE|CMD_RESET);
+	ehci->command |= CMD_RUN;
+	ehci_writel(ehci, ehci->command, &ehci->regs->command);
+
+	down_write(&ehci_cf_port_reset_rwsem);
+	ehci_writel(ehci, FLAG_CF, &ehci->regs->configured_flag);
+	/* flush posted writes */
+	ehci_readl(ehci, &ehci->regs->command);
+	up_write(&ehci_cf_port_reset_rwsem);
+}
+
+static int tegra_usb_suspend(struct usb_hcd *hcd)
+{
+	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
+	struct ehci_regs __iomem *hw = tegra->ehci->regs;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tegra->ehci->lock, flags);
+
+	tegra->port_speed = (readl(&hw->port_status[0]) >> 26) & 0x3;
+	ehci_halt(tegra->ehci);
+	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+
+	spin_unlock_irqrestore(&tegra->ehci->lock, flags);
+
+	tegra_ehci_power_down(hcd);
+	return 0;
+}
+
+static int tegra_usb_resume(struct usb_hcd *hcd)
+{
+	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
+	struct ehci_hcd	*ehci = hcd_to_ehci(hcd);
+	struct ehci_regs __iomem *hw = ehci->regs;
+	unsigned long val;
+
+	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+	tegra_ehci_power_up(hcd);
+
+	if (tegra->port_speed > TEGRA_USB_PHY_PORT_SPEED_HIGH) {
+		/* Wait for the phy to detect new devices
+		 * before we restart the controller */
+		msleep(10);
+		goto restart;
+	}
+
+	/* Force the phy to keep data lines in suspend state */
+	tegra_ehci_phy_restore_start(tegra->phy, tegra->port_speed);
+
+	/* Enable host mode */
+	tdi_reset(ehci);
+
+	/* Enable Port Power */
+	val = readl(&hw->port_status[0]);
+	val |= PORT_POWER;
+	writel(val, &hw->port_status[0]);
+	udelay(10);
+
+	/* Check if the phy resume from LP0. When the phy resume from LP0
+	 * USB register will be reset. */
+	if (!readl(&hw->async_next)) {
+		/* Program the field PTC based on the saved speed mode */
+		val = readl(&hw->port_status[0]);
+		val &= ~PORT_TEST(~0);
+		if (tegra->port_speed == TEGRA_USB_PHY_PORT_SPEED_HIGH)
+			val |= PORT_TEST_FORCE;
+		else if (tegra->port_speed == TEGRA_USB_PHY_PORT_SPEED_FULL)
+			val |= PORT_TEST(6);
+		else if (tegra->port_speed == TEGRA_USB_PHY_PORT_SPEED_LOW)
+			val |= PORT_TEST(7);
+		writel(val, &hw->port_status[0]);
+		udelay(10);
+
+		/* Disable test mode by setting PTC field to NORMAL_OP */
+		val = readl(&hw->port_status[0]);
+		val &= ~PORT_TEST(~0);
+		writel(val, &hw->port_status[0]);
+		udelay(10);
+	}
+
+	/* Poll until CCS is enabled */
+	if (handshake(ehci, &hw->port_status[0], PORT_CONNECT,
+						 PORT_CONNECT, 2000)) {
+		pr_err("%s: timeout waiting for PORT_CONNECT\n", __func__);
+		goto restart;
+	}
+
+	/* Poll until PE is enabled */
+	if (handshake(ehci, &hw->port_status[0], PORT_PE,
+						 PORT_PE, 2000)) {
+		pr_err("%s: timeout waiting for USB_PORTSC1_PE\n", __func__);
+		goto restart;
+	}
+
+	/* Clear the PCI status, to avoid an interrupt taken upon resume */
+	val = readl(&hw->status);
+	val |= STS_PCD;
+	writel(val, &hw->status);
+
+	/* Put controller in suspend mode by writing 1 to SUSP bit of PORTSC */
+	val = readl(&hw->port_status[0]);
+	if ((val & PORT_POWER) && (val & PORT_PE)) {
+		val |= PORT_SUSPEND;
+		writel(val, &hw->port_status[0]);
+
+		/* Wait until port suspend completes */
+		if (handshake(ehci, &hw->port_status[0], PORT_SUSPEND,
+							 PORT_SUSPEND, 1000)) {
+			pr_err("%s: timeout waiting for PORT_SUSPEND\n",
+								__func__);
+			goto restart;
+		}
+	}
+
+	tegra_ehci_phy_restore_end(tegra->phy);
+	return 0;
+
+restart:
+	if (tegra->port_speed <= TEGRA_USB_PHY_PORT_SPEED_HIGH)
+		tegra_ehci_phy_restore_end(tegra->phy);
+
+	tegra_ehci_restart(hcd);
+	return 0;
+}
+
+static void tegra_ehci_shutdown(struct usb_hcd *hcd)
+{
+	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
+
+	/* ehci_shutdown touches the USB controller registers, make sure
+	 * controller has clocks to it */
+	if (!tegra->host_resumed)
+		tegra_ehci_power_up(hcd);
+
+	ehci_shutdown(hcd);
+}
+
+static int tegra_ehci_setup(struct usb_hcd *hcd)
+{
+	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+	int retval;
+
+	/* EHCI registers start at offset 0x100 */
+	ehci->caps = hcd->regs + 0x100;
+	ehci->regs = hcd->regs + 0x100 +
+		HC_LENGTH(readl(&ehci->caps->hc_capbase));
+
+	dbg_hcs_params(ehci, "reset");
+	dbg_hcc_params(ehci, "reset");
+
+	/* cache this readonly data; minimize chip reads */
+	ehci->hcs_params = readl(&ehci->caps->hcs_params);
+
+	/* switch to host mode */
+	hcd->has_tt = 1;
+	ehci_reset(ehci);
+
+	retval = ehci_halt(ehci);
+	if (retval)
+		return retval;
+
+	/* data structure init */
+	retval = ehci_init(hcd);
+	if (retval)
+		return retval;
+
+	ehci->sbrn = 0x20;
+
+	ehci_port_power(ehci, 1);
+	return retval;
+}
+
+#ifdef CONFIG_PM
+static int tegra_ehci_bus_suspend(struct usb_hcd *hcd)
+{
+	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
+	int error_status = 0;
+
+	error_status = ehci_bus_suspend(hcd);
+	if (!error_status && tegra->power_down_on_bus_suspend) {
+		tegra_usb_suspend(hcd);
+		tegra->bus_suspended = 1;
+	}
+
+	return error_status;
+}
+
+static int tegra_ehci_bus_resume(struct usb_hcd *hcd)
+{
+	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
+
+	if (tegra->bus_suspended && tegra->power_down_on_bus_suspend) {
+		tegra_usb_resume(hcd);
+		tegra->bus_suspended = 0;
+	}
+
+	tegra_usb_phy_preresume(tegra->phy);
+	tegra->port_resuming = 1;
+	return ehci_bus_resume(hcd);
+}
+#endif
+
+static const struct hc_driver tegra_ehci_hc_driver = {
+	.description		= hcd_name,
+	.product_desc		= "Tegra EHCI Host Controller",
+	.hcd_priv_size		= sizeof(struct ehci_hcd),
+
+	.flags			= HCD_USB2 | HCD_MEMORY,
+
+	.reset			= tegra_ehci_setup,
+	.irq			= ehci_irq,
+
+	.start			= ehci_run,
+	.stop			= ehci_stop,
+	.shutdown		= tegra_ehci_shutdown,
+	.urb_enqueue		= ehci_urb_enqueue,
+	.urb_dequeue		= ehci_urb_dequeue,
+	.endpoint_disable	= ehci_endpoint_disable,
+	.endpoint_reset		= ehci_endpoint_reset,
+	.get_frame_number	= ehci_get_frame,
+	.hub_status_data	= ehci_hub_status_data,
+	.hub_control		= tegra_ehci_hub_control,
+	.clear_tt_buffer_complete = ehci_clear_tt_buffer_complete,
+#ifdef CONFIG_PM
+	.bus_suspend		= tegra_ehci_bus_suspend,
+	.bus_resume		= tegra_ehci_bus_resume,
+#endif
+	.relinquish_port	= ehci_relinquish_port,
+	.port_handed_over	= ehci_port_handed_over,
+};
+
+static int tegra_ehci_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct usb_hcd *hcd;
+	struct tegra_ehci_hcd *tegra;
+	struct tegra_ehci_platform_data *pdata;
+	int err = 0;
+	int irq;
+	int instance = pdev->id;
+
+	pdata = pdev->dev.platform_data;
+	if (!pdata) {
+		dev_err(&pdev->dev, "Platform data missing\n");
+		return -EINVAL;
+	}
+
+	tegra = kzalloc(sizeof(struct tegra_ehci_hcd), GFP_KERNEL);
+	if (!tegra)
+		return -ENOMEM;
+
+	hcd = usb_create_hcd(&tegra_ehci_hc_driver, &pdev->dev,
+					dev_name(&pdev->dev));
+	if (!hcd) {
+		dev_err(&pdev->dev, "Unable to create HCD\n");
+		err = -ENOMEM;
+		goto fail_hcd;
+	}
+
+	platform_set_drvdata(pdev, tegra);
+
+	tegra->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(tegra->clk)) {
+		dev_err(&pdev->dev, "Can't get ehci clock\n");
+		err = PTR_ERR(tegra->clk);
+		goto fail_clk;
+	}
+
+	err = clk_enable(tegra->clk);
+	if (err)
+		goto fail_clken;
+
+	tegra->emc_clk = clk_get(&pdev->dev, "emc");
+	if (IS_ERR(tegra->emc_clk)) {
+		dev_err(&pdev->dev, "Can't get emc clock\n");
+		err = PTR_ERR(tegra->emc_clk);
+		goto fail_emc_clk;
+	}
+
+	clk_enable(tegra->emc_clk);
+	clk_set_rate(tegra->emc_clk, 400000000);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "Failed to get I/O memory\n");
+		err = -ENXIO;
+		goto fail_io;
+	}
+	hcd->rsrc_start = res->start;
+	hcd->rsrc_len = resource_size(res);
+	hcd->regs = ioremap(res->start, resource_size(res));
+	if (!hcd->regs) {
+		dev_err(&pdev->dev, "Failed to remap I/O memory\n");
+		err = -ENOMEM;
+		goto fail_io;
+	}
+
+	tegra->phy = tegra_usb_phy_open(instance, hcd->regs, pdata->phy_config,
+						TEGRA_USB_PHY_MODE_HOST);
+	if (IS_ERR(tegra->phy)) {
+		dev_err(&pdev->dev, "Failed to open USB phy\n");
+		err = -ENXIO;
+		goto fail_phy;
+	}
+
+	err = tegra_usb_phy_power_on(tegra->phy);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to power on the phy\n");
+		goto fail;
+	}
+
+	tegra->host_resumed = 1;
+	tegra->power_down_on_bus_suspend = pdata->power_down_on_bus_suspend;
+	tegra->ehci = hcd_to_ehci(hcd);
+
+	irq = platform_get_irq(pdev, 0);
+	if (!irq) {
+		dev_err(&pdev->dev, "Failed to get IRQ\n");
+		err = -ENODEV;
+		goto fail;
+	}
+	set_irq_flags(irq, IRQF_VALID);
+
+#ifdef CONFIG_USB_OTG_UTILS
+	if (pdata->operating_mode == TEGRA_USB_OTG) {
+		tegra->transceiver = otg_get_transceiver();
+		if (tegra->transceiver)
+			otg_set_host(tegra->transceiver, &hcd->self);
+	}
+#endif
+
+	err = usb_add_hcd(hcd, irq, IRQF_DISABLED | IRQF_SHARED);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to add USB HCD\n");
+		goto fail;
+	}
+
+	return err;
+
+fail:
+#ifdef CONFIG_USB_OTG_UTILS
+	if (tegra->transceiver) {
+		otg_set_host(tegra->transceiver, NULL);
+		otg_put_transceiver(tegra->transceiver);
+	}
+#endif
+	tegra_usb_phy_close(tegra->phy);
+fail_phy:
+	iounmap(hcd->regs);
+fail_io:
+	clk_disable(tegra->emc_clk);
+	clk_put(tegra->emc_clk);
+fail_emc_clk:
+	clk_disable(tegra->clk);
+fail_clken:
+	clk_put(tegra->clk);
+fail_clk:
+	usb_put_hcd(hcd);
+fail_hcd:
+	kfree(tegra);
+	return err;
+}
+
+#ifdef CONFIG_PM
+static int tegra_ehci_resume(struct platform_device *pdev)
+{
+	struct tegra_ehci_hcd *tegra = platform_get_drvdata(pdev);
+	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);
+
+	if (tegra->bus_suspended)
+		return 0;
+
+	return tegra_usb_resume(hcd);
+}
+
+static int tegra_ehci_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct tegra_ehci_hcd *tegra = platform_get_drvdata(pdev);
+	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);
+
+	if (tegra->bus_suspended)
+		return 0;
+
+	if (time_before(jiffies, tegra->ehci->next_statechange))
+		msleep(10);
+
+	return tegra_usb_suspend(hcd);
+}
+#endif
+
+static int tegra_ehci_remove(struct platform_device *pdev)
+{
+	struct tegra_ehci_hcd *tegra = platform_get_drvdata(pdev);
+	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);
+
+	if (tegra == NULL || hcd == NULL)
+		return -EINVAL;
+
+#ifdef CONFIG_USB_OTG_UTILS
+	if (tegra->transceiver) {
+		otg_set_host(tegra->transceiver, NULL);
+		otg_put_transceiver(tegra->transceiver);
+	}
+#endif
+
+	usb_remove_hcd(hcd);
+	usb_put_hcd(hcd);
+
+	tegra_usb_phy_close(tegra->phy);
+	iounmap(hcd->regs);
+
+	clk_disable(tegra->clk);
+	clk_put(tegra->clk);
+
+	clk_disable(tegra->emc_clk);
+	clk_put(tegra->emc_clk);
+
+	kfree(tegra);
+	return 0;
+}
+
+static void tegra_ehci_hcd_shutdown(struct platform_device *pdev)
+{
+	struct tegra_ehci_hcd *tegra = platform_get_drvdata(pdev);
+	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);
+
+	if (hcd->driver->shutdown)
+		hcd->driver->shutdown(hcd);
+}
+
+static struct platform_driver tegra_ehci_driver = {
+	.probe		= tegra_ehci_probe,
+	.remove		= tegra_ehci_remove,
+#ifdef CONFIG_PM
+	.suspend	= tegra_ehci_suspend,
+	.resume		= tegra_ehci_resume,
+#endif
+	.shutdown	= tegra_ehci_hcd_shutdown,
+	.driver		= {
+		.name	= "tegra-ehci",
+	}
+};