usb: musb: introduce DA8xx/OMAP-L1x glue layer

Texas Instruments DA8xx/OMAP-L1x glue layer for the
MUSBMHRDC driver.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Yadviga Grigorieva <yadviga@ru.mvista.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 469 insertions, 0 deletions

diff --git a/drivers/usb/musb/da8xx.c b/drivers/usb/musb/da8xx.c
new file mode 100644
index 000000000000..84427bebbf62
--- /dev/null
+++ b/drivers/usb/musb/da8xx.c
@@ -0,0 +1,469 @@
+/*
+ * Texas Instruments DA8xx/OMAP-L1x "glue layer"
+ *
+ * Copyright (c) 2008-2009 MontaVista Software, Inc. <source@mvista.com>
+ *
+ * Based on the DaVinci "glue layer" code.
+ * Copyright (C) 2005-2006 by Texas Instruments
+ *
+ * This file is part of the Inventra Controller Driver for Linux.
+ *
+ * The Inventra Controller Driver for Linux is free software; you
+ * can redistribute it and/or modify it under the terms of the GNU
+ * General Public License version 2 as published by the Free Software
+ * Foundation.
+ *
+ * The Inventra Controller Driver for Linux 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with The Inventra Controller Driver for Linux ; if not,
+ * write to the Free Software Foundation, Inc., 59 Temple Place,
+ * Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <mach/da8xx.h>
+#include <mach/usb.h>
+
+#include "musb_core.h"
+
+/*
+ * DA8XX specific definitions
+ */
+
+/* USB 2.0 OTG module registers */
+#define DA8XX_USB_REVISION_REG	0x00
+#define DA8XX_USB_CTRL_REG	0x04
+#define DA8XX_USB_STAT_REG	0x08
+#define DA8XX_USB_EMULATION_REG 0x0c
+#define DA8XX_USB_MODE_REG	0x10	/* Transparent, CDC, [Generic] RNDIS */
+#define DA8XX_USB_AUTOREQ_REG	0x14
+#define DA8XX_USB_SRP_FIX_TIME_REG 0x18
+#define DA8XX_USB_TEARDOWN_REG	0x1c
+#define DA8XX_USB_INTR_SRC_REG	0x20
+#define DA8XX_USB_INTR_SRC_SET_REG 0x24
+#define DA8XX_USB_INTR_SRC_CLEAR_REG 0x28
+#define DA8XX_USB_INTR_MASK_REG 0x2c
+#define DA8XX_USB_INTR_MASK_SET_REG 0x30
+#define DA8XX_USB_INTR_MASK_CLEAR_REG 0x34
+#define DA8XX_USB_INTR_SRC_MASKED_REG 0x38
+#define DA8XX_USB_END_OF_INTR_REG 0x3c
+#define DA8XX_USB_GENERIC_RNDIS_EP_SIZE_REG(n) (0x50 + (((n) - 1) << 2))
+
+/* Control register bits */
+#define DA8XX_SOFT_RESET_MASK	1
+
+#define DA8XX_USB_TX_EP_MASK	0x1f		/* EP0 + 4 Tx EPs */
+#define DA8XX_USB_RX_EP_MASK	0x1e		/* 4 Rx EPs */
+
+/* USB interrupt register bits */
+#define DA8XX_INTR_USB_SHIFT	16
+#define DA8XX_INTR_USB_MASK	(0x1ff << DA8XX_INTR_USB_SHIFT) /* 8 Mentor */
+					/* interrupts and DRVVBUS interrupt */
+#define DA8XX_INTR_DRVVBUS	0x100
+#define DA8XX_INTR_RX_SHIFT	8
+#define DA8XX_INTR_RX_MASK	(DA8XX_USB_RX_EP_MASK << DA8XX_INTR_RX_SHIFT)
+#define DA8XX_INTR_TX_SHIFT	0
+#define DA8XX_INTR_TX_MASK	(DA8XX_USB_TX_EP_MASK << DA8XX_INTR_TX_SHIFT)
+
+#define DA8XX_MENTOR_CORE_OFFSET 0x400
+
+#define CFGCHIP2	IO_ADDRESS(DA8XX_SYSCFG0_BASE + DA8XX_CFGCHIP2_REG)
+
+/*
+ * REVISIT (PM): we should be able to keep the PHY in low power mode most
+ * of the time (24 MHz oscillator and PLL off, etc.) by setting POWER.D0
+ * and, when in host mode, autosuspending idle root ports... PHY_PLLON
+ * (overriding SUSPENDM?) then likely needs to stay off.
+ */
+
+static inline void phy_on(void)
+{
+	u32 cfgchip2 = __raw_readl(CFGCHIP2);
+
+	/*
+	 * Start the on-chip PHY and its PLL.
+	 */
+	cfgchip2 &= ~(CFGCHIP2_RESET | CFGCHIP2_PHYPWRDN | CFGCHIP2_OTGPWRDN);
+	cfgchip2 |= CFGCHIP2_PHY_PLLON;
+	__raw_writel(cfgchip2, CFGCHIP2);
+
+	pr_info("Waiting for USB PHY clock good...\n");
+	while (!(__raw_readl(CFGCHIP2) & CFGCHIP2_PHYCLKGD))
+		cpu_relax();
+}
+
+static inline void phy_off(void)
+{
+	u32 cfgchip2 = __raw_readl(CFGCHIP2);
+
+	/*
+	 * Ensure that USB 1.1 reference clock is not being sourced from
+	 * USB 2.0 PHY.  Otherwise do not power down the PHY.
+	 */
+	if (!(cfgchip2 & CFGCHIP2_USB1PHYCLKMUX) &&
+	     (cfgchip2 & CFGCHIP2_USB1SUSPENDM)) {
+		pr_warning("USB 1.1 clocked from USB 2.0 PHY -- "
+			   "can't power it down\n");
+		return;
+	}
+
+	/*
+	 * Power down the on-chip PHY.
+	 */
+	cfgchip2 |= CFGCHIP2_PHYPWRDN | CFGCHIP2_OTGPWRDN;
+	__raw_writel(cfgchip2, CFGCHIP2);
+}
+
+/*
+ * Because we don't set CTRL.UINT, it's "important" to:
+ *	- not read/write INTRUSB/INTRUSBE (except during
+ *	  initial setup, as a workaround);
+ *	- use INTSET/INTCLR instead.
+ */
+
+/**
+ * musb_platform_enable - enable interrupts
+ */
+void musb_platform_enable(struct musb *musb)
+{
+	void __iomem *reg_base = musb->ctrl_base;
+	u32 mask;
+
+	/* Workaround: setup IRQs through both register sets. */
+	mask = ((musb->epmask & DA8XX_USB_TX_EP_MASK) << DA8XX_INTR_TX_SHIFT) |
+	       ((musb->epmask & DA8XX_USB_RX_EP_MASK) << DA8XX_INTR_RX_SHIFT) |
+	       DA8XX_INTR_USB_MASK;
+	musb_writel(reg_base, DA8XX_USB_INTR_MASK_SET_REG, mask);
+
+	/* Force the DRVVBUS IRQ so we can start polling for ID change. */
+	if (is_otg_enabled(musb))
+		musb_writel(reg_base, DA8XX_USB_INTR_SRC_SET_REG,
+			    DA8XX_INTR_DRVVBUS << DA8XX_INTR_USB_SHIFT);
+}
+
+/**
+ * musb_platform_disable - disable HDRC and flush interrupts
+ */
+void musb_platform_disable(struct musb *musb)
+{
+	void __iomem *reg_base = musb->ctrl_base;
+
+	musb_writel(reg_base, DA8XX_USB_INTR_MASK_CLEAR_REG,
+		    DA8XX_INTR_USB_MASK |
+		    DA8XX_INTR_TX_MASK | DA8XX_INTR_RX_MASK);
+	musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
+	musb_writel(reg_base, DA8XX_USB_END_OF_INTR_REG, 0);
+}
+
+#ifdef CONFIG_USB_MUSB_HDRC_HCD
+#define portstate(stmt) 	stmt
+#else
+#define portstate(stmt)
+#endif
+
+static void da8xx_set_vbus(struct musb *musb, int is_on)
+{
+	WARN_ON(is_on && is_peripheral_active(musb));
+}
+
+#define	POLL_SECONDS	2
+
+static struct timer_list otg_workaround;
+
+static void otg_timer(unsigned long _musb)
+{
+	struct musb		*musb = (void *)_musb;
+	void __iomem		*mregs = musb->mregs;
+	u8			devctl;
+	unsigned long		flags;
+
+	/*
+	 * We poll because DaVinci's won't expose several OTG-critical
+	 * status change events (from the transceiver) otherwise.
+	 */
+	devctl = musb_readb(mregs, MUSB_DEVCTL);
+	DBG(7, "Poll devctl %02x (%s)\n", devctl, otg_state_string(musb));
+
+	spin_lock_irqsave(&musb->lock, flags);
+	switch (musb->xceiv->state) {
+	case OTG_STATE_A_WAIT_BCON:
+		devctl &= ~MUSB_DEVCTL_SESSION;
+		musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
+
+		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
+		if (devctl & MUSB_DEVCTL_BDEVICE) {
+			musb->xceiv->state = OTG_STATE_B_IDLE;
+			MUSB_DEV_MODE(musb);
+		} else {
+			musb->xceiv->state = OTG_STATE_A_IDLE;
+			MUSB_HST_MODE(musb);
+		}
+		break;
+	case OTG_STATE_A_WAIT_VFALL:
+		/*
+		 * Wait till VBUS falls below SessionEnd (~0.2 V); the 1.3
+		 * RTL seems to mis-handle session "start" otherwise (or in
+		 * our case "recover"), in routine "VBUS was valid by the time
+		 * VBUSERR got reported during enumeration" cases.
+		 */
+		if (devctl & MUSB_DEVCTL_VBUS) {
+			mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
+			break;
+		}
+		musb->xceiv->state = OTG_STATE_A_WAIT_VRISE;
+		musb_writel(musb->ctrl_base, DA8XX_USB_INTR_SRC_SET_REG,
+			    MUSB_INTR_VBUSERROR << DA8XX_INTR_USB_SHIFT);
+		break;
+	case OTG_STATE_B_IDLE:
+		if (!is_peripheral_enabled(musb))
+			break;
+
+		/*
+		 * There's no ID-changed IRQ, so we have no good way to tell
+		 * when to switch to the A-Default state machine (by setting
+		 * the DEVCTL.Session bit).
+		 *
+		 * Workaround:  whenever we're in B_IDLE, try setting the
+		 * session flag every few seconds.  If it works, ID was
+		 * grounded and we're now in the A-Default state machine.
+		 *
+		 * NOTE: setting the session flag is _supposed_ to trigger
+		 * SRP but clearly it doesn't.
+		 */
+		musb_writeb(mregs, MUSB_DEVCTL, devctl | MUSB_DEVCTL_SESSION);
+		devctl = musb_readb(mregs, MUSB_DEVCTL);
+		if (devctl & MUSB_DEVCTL_BDEVICE)
+			mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
+		else
+			musb->xceiv->state = OTG_STATE_A_IDLE;
+		break;
+	default:
+		break;
+	}
+	spin_unlock_irqrestore(&musb->lock, flags);
+}
+
+void musb_platform_try_idle(struct musb *musb, unsigned long timeout)
+{
+	static unsigned long last_timer;
+
+	if (!is_otg_enabled(musb))
+		return;
+
+	if (timeout == 0)
+		timeout = jiffies + msecs_to_jiffies(3);
+
+	/* Never idle if active, or when VBUS timeout is not set as host */
+	if (musb->is_active || (musb->a_wait_bcon == 0 &&
+				musb->xceiv->state == OTG_STATE_A_WAIT_BCON)) {
+		DBG(4, "%s active, deleting timer\n", otg_state_string(musb));
+		del_timer(&otg_workaround);
+		last_timer = jiffies;
+		return;
+	}
+
+	if (time_after(last_timer, timeout) && timer_pending(&otg_workaround)) {
+		DBG(4, "Longer idle timer already pending, ignoring...\n");
+		return;
+	}
+	last_timer = timeout;
+
+	DBG(4, "%s inactive, starting idle timer for %u ms\n",
+	    otg_state_string(musb), jiffies_to_msecs(timeout - jiffies));
+	mod_timer(&otg_workaround, timeout);
+}
+
+static irqreturn_t da8xx_interrupt(int irq, void *hci)
+{
+	struct musb		*musb = hci;
+	void __iomem		*reg_base = musb->ctrl_base;
+	unsigned long		flags;
+	irqreturn_t		ret = IRQ_NONE;
+	u32			status;
+
+	spin_lock_irqsave(&musb->lock, flags);
+
+	/*
+	 * NOTE: DA8XX shadows the Mentor IRQs.  Don't manage them through
+	 * the Mentor registers (except for setup), use the TI ones and EOI.
+	 */
+
+	/* Acknowledge and handle non-CPPI interrupts */
+	status = musb_readl(reg_base, DA8XX_USB_INTR_SRC_MASKED_REG);
+	if (!status)
+		goto eoi;
+
+	musb_writel(reg_base, DA8XX_USB_INTR_SRC_CLEAR_REG, status);
+	DBG(4, "USB IRQ %08x\n", status);
+
+	musb->int_rx = (status & DA8XX_INTR_RX_MASK) >> DA8XX_INTR_RX_SHIFT;
+	musb->int_tx = (status & DA8XX_INTR_TX_MASK) >> DA8XX_INTR_TX_SHIFT;
+	musb->int_usb = (status & DA8XX_INTR_USB_MASK) >> DA8XX_INTR_USB_SHIFT;
+
+	/*
+	 * DRVVBUS IRQs are the only proxy we have (a very poor one!) for
+	 * DA8xx's missing ID change IRQ.  We need an ID change IRQ to
+	 * switch appropriately between halves of the OTG state machine.
+	 * Managing DEVCTL.Session per Mentor docs requires that we know its
+	 * value but DEVCTL.BDevice is invalid without DEVCTL.Session set.
+	 * Also, DRVVBUS pulses for SRP (but not at 5 V)...
+	 */
+	if (status & (DA8XX_INTR_DRVVBUS << DA8XX_INTR_USB_SHIFT)) {
+		int drvvbus = musb_readl(reg_base, DA8XX_USB_STAT_REG);
+		void __iomem *mregs = musb->mregs;
+		u8 devctl = musb_readb(mregs, MUSB_DEVCTL);
+		int err;
+
+		err = is_host_enabled(musb) && (musb->int_usb &
+						MUSB_INTR_VBUSERROR);
+		if (err) {
+			/*
+			 * The Mentor core doesn't debounce VBUS as needed
+			 * to cope with device connect current spikes. This
+			 * means it's not uncommon for bus-powered devices
+			 * to get VBUS errors during enumeration.
+			 *
+			 * This is a workaround, but newer RTL from Mentor
+			 * seems to allow a better one: "re"-starting sessions
+			 * without waiting for VBUS to stop registering in
+			 * devctl.
+			 */
+			musb->int_usb &= ~MUSB_INTR_VBUSERROR;
+			musb->xceiv->state = OTG_STATE_A_WAIT_VFALL;
+			mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
+			WARNING("VBUS error workaround (delay coming)\n");
+		} else if (is_host_enabled(musb) && drvvbus) {
+			MUSB_HST_MODE(musb);
+			musb->xceiv->default_a = 1;
+			musb->xceiv->state = OTG_STATE_A_WAIT_VRISE;
+			portstate(musb->port1_status |= USB_PORT_STAT_POWER);
+			del_timer(&otg_workaround);
+		} else {
+			musb->is_active = 0;
+			MUSB_DEV_MODE(musb);
+			musb->xceiv->default_a = 0;
+			musb->xceiv->state = OTG_STATE_B_IDLE;
+			portstate(musb->port1_status &= ~USB_PORT_STAT_POWER);
+		}
+
+		DBG(2, "VBUS %s (%s)%s, devctl %02x\n",
+				drvvbus ? "on" : "off",
+				otg_state_string(musb),
+				err ? " ERROR" : "",
+				devctl);
+		ret = IRQ_HANDLED;
+	}
+
+	if (musb->int_tx || musb->int_rx || musb->int_usb)
+		ret |= musb_interrupt(musb);
+
+ eoi:
+	/* EOI needs to be written for the IRQ to be re-asserted. */
+	if (ret == IRQ_HANDLED || status)
+		musb_writel(reg_base, DA8XX_USB_END_OF_INTR_REG, 0);
+
+	/* Poll for ID change */
+	if (is_otg_enabled(musb) && musb->xceiv->state == OTG_STATE_B_IDLE)
+		mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
+
+	spin_unlock_irqrestore(&musb->lock, flags);
+
+	return ret;
+}
+
+int musb_platform_set_mode(struct musb *musb, u8 musb_mode)
+{
+	u32 cfgchip2 = __raw_readl(CFGCHIP2);
+
+	cfgchip2 &= ~CFGCHIP2_OTGMODE;
+	switch (musb_mode) {
+#ifdef	CONFIG_USB_MUSB_HDRC_HCD
+	case MUSB_HOST:		/* Force VBUS valid, ID = 0 */
+		cfgchip2 |= CFGCHIP2_FORCE_HOST;
+		break;
+#endif
+#ifdef	CONFIG_USB_GADGET_MUSB_HDRC
+	case MUSB_PERIPHERAL:	/* Force VBUS valid, ID = 1 */
+		cfgchip2 |= CFGCHIP2_FORCE_DEVICE;
+		break;
+#endif
+#ifdef	CONFIG_USB_MUSB_OTG
+	case MUSB_OTG:		/* Don't override the VBUS/ID comparators */
+		cfgchip2 |= CFGCHIP2_NO_OVERRIDE;
+		break;
+#endif
+	default:
+		DBG(2, "Trying to set unsupported mode %u\n", musb_mode);
+	}
+
+	__raw_writel(cfgchip2, CFGCHIP2);
+	return 0;
+}
+
+int __init musb_platform_init(struct musb *musb, void *board_data)
+{
+	void __iomem *reg_base = musb->ctrl_base;
+	u32 rev;
+
+	musb->mregs += DA8XX_MENTOR_CORE_OFFSET;
+
+	clk_enable(musb->clock);
+
+	/* Returns zero if e.g. not clocked */
+	rev = musb_readl(reg_base, DA8XX_USB_REVISION_REG);
+	if (!rev)
+		goto fail;
+
+	usb_nop_xceiv_register();
+	musb->xceiv = otg_get_transceiver();
+	if (!musb->xceiv)
+		goto fail;
+
+	if (is_host_enabled(musb))
+		setup_timer(&otg_workaround, otg_timer, (unsigned long)musb);
+
+	musb->board_set_vbus = da8xx_set_vbus;
+
+	/* Reset the controller */
+	musb_writel(reg_base, DA8XX_USB_CTRL_REG, DA8XX_SOFT_RESET_MASK);
+
+	/* Start the on-chip PHY and its PLL. */
+	phy_on();
+
+	msleep(5);
+
+	/* NOTE: IRQs are in mixed mode, not bypass to pure MUSB */
+	pr_debug("DA8xx OTG revision %08x, PHY %03x, control %02x\n",
+		 rev, __raw_readl(CFGCHIP2),
+		 musb_readb(reg_base, DA8XX_USB_CTRL_REG));
+
+	musb->isr = da8xx_interrupt;
+	return 0;
+fail:
+	clk_disable(musb->clock);
+	return -ENODEV;
+}
+
+int musb_platform_exit(struct musb *musb)
+{
+	if (is_host_enabled(musb))
+		del_timer_sync(&otg_workaround);
+
+	phy_off();
+
+	otg_put_transceiver(musb->xceiv);
+	usb_nop_xceiv_unregister();
+
+	clk_disable(musb->clock);
+
+	return 0;
+}