usb: add ab8500 usb transceiver driver

Basic driver for ab8500 usb otg transceiver

TODO:
-Regulators support
-Host and OTG testing
-Interface with PRCMU
-Charging support

Signed-off-by: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 595 insertions, 0 deletions

diff --git a/drivers/usb/otg/Kconfig b/drivers/usb/otg/Kconfig
index 2810c2a..6491717 100644
--- a/drivers/usb/otg/Kconfig
+++ b/drivers/usb/otg/Kconfig
@@ -92,4 +92,13 @@ config USB_MSM_OTG_72K
 	  This driver is required even for peripheral only or host only
 	  mode configurations.
 
+config AB8500_USB
+        tristate "AB8500 USB Transceiver Driver"
+        depends on AB8500_CORE
+        select USB_OTG_UTILS
+        help
+          Enable this to support the USB OTG transceiver in AB8500 chip.
+          This transceiver supports high and full speed devices plus,
+          in host mode, low speed.
+
 endif # USB || OTG
diff --git a/drivers/usb/otg/Makefile b/drivers/usb/otg/Makefile
index 3b1b096..30a23f3 100644
--- a/drivers/usb/otg/Makefile
+++ b/drivers/usb/otg/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_USB_LANGWELL_OTG)	+= langwell_otg.o
 obj-$(CONFIG_NOP_USB_XCEIV)	+= nop-usb-xceiv.o
 obj-$(CONFIG_USB_ULPI)		+= ulpi.o
 obj-$(CONFIG_USB_MSM_OTG_72K)	+= msm72k_otg.o
+obj-$(CONFIG_AB8500_USB)	+= ab8500-usb.o
diff --git a/drivers/usb/otg/ab8500-usb.c b/drivers/usb/otg/ab8500-usb.c
new file mode 100644
index 0000000..d14736b
--- /dev/null
+++ b/drivers/usb/otg/ab8500-usb.c
@@ -0,0 +1,585 @@
+/*
+ * drivers/usb/otg/ab8500_usb.c
+ *
+ * USB transceiver driver for AB8500 chip
+ *
+ * Copyright (C) 2010 ST-Ericsson AB
+ * Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/usb/otg.h>
+#include <linux/slab.h>
+#include <linux/notifier.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/mfd/abx500.h>
+#include <linux/mfd/ab8500.h>
+
+#define AB8500_MAIN_WD_CTRL_REG 0x01
+#define AB8500_USB_LINE_STAT_REG 0x80
+#define AB8500_USB_PHY_CTRL_REG 0x8A
+
+#define AB8500_BIT_OTG_STAT_ID (1 << 0)
+#define AB8500_BIT_PHY_CTRL_HOST_EN (1 << 0)
+#define AB8500_BIT_PHY_CTRL_DEVICE_EN (1 << 1)
+#define AB8500_BIT_WD_CTRL_ENABLE (1 << 0)
+#define AB8500_BIT_WD_CTRL_KICK (1 << 1)
+
+#define AB8500_V1x_LINK_STAT_WAIT (HZ/10)
+#define AB8500_WD_KICK_DELAY_US 100 /* usec */
+#define AB8500_WD_V11_DISABLE_DELAY_US 100 /* usec */
+#define AB8500_WD_V10_DISABLE_DELAY_MS 100 /* ms */
+
+/* Usb line status register */
+enum ab8500_usb_link_status {
+	USB_LINK_NOT_CONFIGURED = 0,
+	USB_LINK_STD_HOST_NC,
+	USB_LINK_STD_HOST_C_NS,
+	USB_LINK_STD_HOST_C_S,
+	USB_LINK_HOST_CHG_NM,
+	USB_LINK_HOST_CHG_HS,
+	USB_LINK_HOST_CHG_HS_CHIRP,
+	USB_LINK_DEDICATED_CHG,
+	USB_LINK_ACA_RID_A,
+	USB_LINK_ACA_RID_B,
+	USB_LINK_ACA_RID_C_NM,
+	USB_LINK_ACA_RID_C_HS,
+	USB_LINK_ACA_RID_C_HS_CHIRP,
+	USB_LINK_HM_IDGND,
+	USB_LINK_RESERVED,
+	USB_LINK_NOT_VALID_LINK
+};
+
+struct ab8500_usb {
+	struct otg_transceiver otg;
+	struct device *dev;
+	int irq_num_id_rise;
+	int irq_num_id_fall;
+	int irq_num_vbus_rise;
+	int irq_num_vbus_fall;
+	int irq_num_link_status;
+	unsigned vbus_draw;
+	struct delayed_work dwork;
+	struct work_struct phy_dis_work;
+	unsigned long link_status_wait;
+	int rev;
+};
+
+static inline struct ab8500_usb *xceiv_to_ab(struct otg_transceiver *x)
+{
+	return container_of(x, struct ab8500_usb, otg);
+}
+
+static void ab8500_usb_wd_workaround(struct ab8500_usb *ab)
+{
+	abx500_set_register_interruptible(ab->dev,
+		AB8500_SYS_CTRL2_BLOCK,
+		AB8500_MAIN_WD_CTRL_REG,
+		AB8500_BIT_WD_CTRL_ENABLE);
+
+	udelay(AB8500_WD_KICK_DELAY_US);
+
+	abx500_set_register_interruptible(ab->dev,
+		AB8500_SYS_CTRL2_BLOCK,
+		AB8500_MAIN_WD_CTRL_REG,
+		(AB8500_BIT_WD_CTRL_ENABLE
+		| AB8500_BIT_WD_CTRL_KICK));
+
+	if (ab->rev > 0x10) /* v1.1 v2.0 */
+		udelay(AB8500_WD_V11_DISABLE_DELAY_US);
+	else /* v1.0 */
+		msleep(AB8500_WD_V10_DISABLE_DELAY_MS);
+
+	abx500_set_register_interruptible(ab->dev,
+		AB8500_SYS_CTRL2_BLOCK,
+		AB8500_MAIN_WD_CTRL_REG,
+		0);
+}
+
+static void ab8500_usb_phy_ctrl(struct ab8500_usb *ab, bool sel_host,
+					bool enable)
+{
+	u8 ctrl_reg;
+	abx500_get_register_interruptible(ab->dev,
+				AB8500_USB,
+				AB8500_USB_PHY_CTRL_REG,
+				&ctrl_reg);
+	if (sel_host) {
+		if (enable)
+			ctrl_reg |= AB8500_BIT_PHY_CTRL_HOST_EN;
+		else
+			ctrl_reg &= ~AB8500_BIT_PHY_CTRL_HOST_EN;
+	} else {
+		if (enable)
+			ctrl_reg |= AB8500_BIT_PHY_CTRL_DEVICE_EN;
+		else
+			ctrl_reg &= ~AB8500_BIT_PHY_CTRL_DEVICE_EN;
+	}
+
+	abx500_set_register_interruptible(ab->dev,
+				AB8500_USB,
+				AB8500_USB_PHY_CTRL_REG,
+				ctrl_reg);
+
+	/* Needed to enable the phy.*/
+	if (enable)
+		ab8500_usb_wd_workaround(ab);
+}
+
+#define ab8500_usb_host_phy_en(ab)	ab8500_usb_phy_ctrl(ab, true, true)
+#define ab8500_usb_host_phy_dis(ab)	ab8500_usb_phy_ctrl(ab, true, false)
+#define ab8500_usb_peri_phy_en(ab)	ab8500_usb_phy_ctrl(ab, false, true)
+#define ab8500_usb_peri_phy_dis(ab)	ab8500_usb_phy_ctrl(ab, false, false)
+
+static int ab8500_usb_link_status_update(struct ab8500_usb *ab)
+{
+	u8 reg;
+	enum ab8500_usb_link_status lsts;
+	void *v = NULL;
+	enum usb_xceiv_events event;
+
+	abx500_get_register_interruptible(ab->dev,
+			AB8500_USB,
+			AB8500_USB_LINE_STAT_REG,
+			&reg);
+
+	lsts = (reg >> 3) & 0x0F;
+
+	switch (lsts) {
+	case USB_LINK_NOT_CONFIGURED:
+	case USB_LINK_RESERVED:
+	case USB_LINK_NOT_VALID_LINK:
+		/* TODO: Disable regulators. */
+		ab8500_usb_host_phy_dis(ab);
+		ab8500_usb_peri_phy_dis(ab);
+		ab->otg.state = OTG_STATE_B_IDLE;
+		ab->otg.default_a = false;
+		ab->vbus_draw = 0;
+		event = USB_EVENT_NONE;
+		break;
+
+	case USB_LINK_STD_HOST_NC:
+	case USB_LINK_STD_HOST_C_NS:
+	case USB_LINK_STD_HOST_C_S:
+	case USB_LINK_HOST_CHG_NM:
+	case USB_LINK_HOST_CHG_HS:
+	case USB_LINK_HOST_CHG_HS_CHIRP:
+		if (ab->otg.gadget) {
+			/* TODO: Enable regulators. */
+			ab8500_usb_peri_phy_en(ab);
+			v = ab->otg.gadget;
+		}
+		event = USB_EVENT_VBUS;
+		break;
+
+	case USB_LINK_HM_IDGND:
+		if (ab->otg.host) {
+			/* TODO: Enable regulators. */
+			ab8500_usb_host_phy_en(ab);
+			v = ab->otg.host;
+		}
+		ab->otg.state = OTG_STATE_A_IDLE;
+		ab->otg.default_a = true;
+		event = USB_EVENT_ID;
+		break;
+
+	case USB_LINK_ACA_RID_A:
+	case USB_LINK_ACA_RID_B:
+		/* TODO */
+	case USB_LINK_ACA_RID_C_NM:
+	case USB_LINK_ACA_RID_C_HS:
+	case USB_LINK_ACA_RID_C_HS_CHIRP:
+	case USB_LINK_DEDICATED_CHG:
+		/* TODO: vbus_draw */
+		event = USB_EVENT_CHARGER;
+		break;
+	}
+
+	blocking_notifier_call_chain(&ab->otg.notifier, event, v);
+
+	return 0;
+}
+
+static void ab8500_usb_delayed_work(struct work_struct *work)
+{
+	struct ab8500_usb *ab = container_of(work, struct ab8500_usb,
+						dwork.work);
+
+	ab8500_usb_link_status_update(ab);
+}
+
+static irqreturn_t ab8500_usb_v1x_common_irq(int irq, void *data)
+{
+	struct ab8500_usb *ab = (struct ab8500_usb *) data;
+
+	/* Wait for link status to become stable. */
+	schedule_delayed_work(&ab->dwork, ab->link_status_wait);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ab8500_usb_v1x_vbus_fall_irq(int irq, void *data)
+{
+	struct ab8500_usb *ab = (struct ab8500_usb *) data;
+
+	/* Link status will not be updated till phy is disabled. */
+	ab8500_usb_peri_phy_dis(ab);
+
+	/* Wait for link status to become stable. */
+	schedule_delayed_work(&ab->dwork, ab->link_status_wait);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ab8500_usb_v20_irq(int irq, void *data)
+{
+	struct ab8500_usb *ab = (struct ab8500_usb *) data;
+
+	ab8500_usb_link_status_update(ab);
+
+	return IRQ_HANDLED;
+}
+
+static void ab8500_usb_phy_disable_work(struct work_struct *work)
+{
+	struct ab8500_usb *ab = container_of(work, struct ab8500_usb,
+						phy_dis_work);
+
+	if (!ab->otg.host)
+		ab8500_usb_host_phy_dis(ab);
+
+	if (!ab->otg.gadget)
+		ab8500_usb_peri_phy_dis(ab);
+}
+
+static int ab8500_usb_set_power(struct otg_transceiver *otg, unsigned mA)
+{
+	struct ab8500_usb *ab;
+
+	if (!otg)
+		return -ENODEV;
+
+	ab = xceiv_to_ab(otg);
+
+	ab->vbus_draw = mA;
+
+	if (mA)
+		blocking_notifier_call_chain(&ab->otg.notifier,
+				USB_EVENT_ENUMERATED, ab->otg.gadget);
+	return 0;
+}
+
+/* TODO: Implement some way for charging or other drivers to read
+ * ab->vbus_draw.
+ */
+
+static int ab8500_usb_set_suspend(struct otg_transceiver *x, int suspend)
+{
+	/* TODO */
+	return 0;
+}
+
+static int ab8500_usb_set_peripheral(struct otg_transceiver *otg,
+		struct usb_gadget *gadget)
+{
+	struct ab8500_usb *ab;
+
+	if (!otg)
+		return -ENODEV;
+
+	ab = xceiv_to_ab(otg);
+
+	/* Some drivers call this function in atomic context.
+	 * Do not update ab8500 registers directly till this
+	 * is fixed.
+	 */
+
+	if (!gadget) {
+		/* TODO: Disable regulators. */
+		ab->otg.gadget = NULL;
+		schedule_work(&ab->phy_dis_work);
+	} else {
+		ab->otg.gadget = gadget;
+		ab->otg.state = OTG_STATE_B_IDLE;
+
+		/* Phy will not be enabled if cable is already
+		 * plugged-in. Schedule to enable phy.
+		 * Use same delay to avoid any race condition.
+		 */
+		schedule_delayed_work(&ab->dwork, ab->link_status_wait);
+	}
+
+	return 0;
+}
+
+static int ab8500_usb_set_host(struct otg_transceiver *otg,
+					struct usb_bus *host)
+{
+	struct ab8500_usb *ab;
+
+	if (!otg)
+		return -ENODEV;
+
+	ab = xceiv_to_ab(otg);
+
+	/* Some drivers call this function in atomic context.
+	 * Do not update ab8500 registers directly till this
+	 * is fixed.
+	 */
+
+	if (!host) {
+		/* TODO: Disable regulators. */
+		ab->otg.host = NULL;
+		schedule_work(&ab->phy_dis_work);
+	} else {
+		ab->otg.host = host;
+		/* Phy will not be enabled if cable is already
+		 * plugged-in. Schedule to enable phy.
+		 * Use same delay to avoid any race condition.
+		 */
+		schedule_delayed_work(&ab->dwork, ab->link_status_wait);
+	}
+
+	return 0;
+}
+
+static void ab8500_usb_irq_free(struct ab8500_usb *ab)
+{
+	if (ab->rev < 0x20) {
+		free_irq(ab->irq_num_id_rise, ab);
+		free_irq(ab->irq_num_id_fall, ab);
+		free_irq(ab->irq_num_vbus_rise, ab);
+		free_irq(ab->irq_num_vbus_fall, ab);
+	} else {
+		free_irq(ab->irq_num_link_status, ab);
+	}
+}
+
+static int ab8500_usb_v1x_res_setup(struct platform_device *pdev,
+				struct ab8500_usb *ab)
+{
+	int err;
+
+	ab->irq_num_id_rise = platform_get_irq_byname(pdev, "ID_WAKEUP_R");
+	if (ab->irq_num_id_rise < 0) {
+		dev_err(&pdev->dev, "ID rise irq not found\n");
+		return ab->irq_num_id_rise;
+	}
+	err = request_threaded_irq(ab->irq_num_id_rise, NULL,
+		ab8500_usb_v1x_common_irq,
+		IRQF_NO_SUSPEND | IRQF_SHARED,
+		"usb-id-rise", ab);
+	if (err < 0) {
+		dev_err(ab->dev, "request_irq failed for ID rise irq\n");
+		goto fail0;
+	}
+
+	ab->irq_num_id_fall = platform_get_irq_byname(pdev, "ID_WAKEUP_F");
+	if (ab->irq_num_id_fall < 0) {
+		dev_err(&pdev->dev, "ID fall irq not found\n");
+		return ab->irq_num_id_fall;
+	}
+	err = request_threaded_irq(ab->irq_num_id_fall, NULL,
+		ab8500_usb_v1x_common_irq,
+		IRQF_NO_SUSPEND | IRQF_SHARED,
+		"usb-id-fall", ab);
+	if (err < 0) {
+		dev_err(ab->dev, "request_irq failed for ID fall irq\n");
+		goto fail1;
+	}
+
+	ab->irq_num_vbus_rise = platform_get_irq_byname(pdev, "VBUS_DET_R");
+	if (ab->irq_num_vbus_rise < 0) {
+		dev_err(&pdev->dev, "VBUS rise irq not found\n");
+		return ab->irq_num_vbus_rise;
+	}
+	err = request_threaded_irq(ab->irq_num_vbus_rise, NULL,
+		ab8500_usb_v1x_common_irq,
+		IRQF_NO_SUSPEND | IRQF_SHARED,
+		"usb-vbus-rise", ab);
+	if (err < 0) {
+		dev_err(ab->dev, "request_irq failed for Vbus rise irq\n");
+		goto fail2;
+	}
+
+	ab->irq_num_vbus_fall = platform_get_irq_byname(pdev, "VBUS_DET_F");
+	if (ab->irq_num_vbus_fall < 0) {
+		dev_err(&pdev->dev, "VBUS fall irq not found\n");
+		return ab->irq_num_vbus_fall;
+	}
+	err = request_threaded_irq(ab->irq_num_vbus_fall, NULL,
+		ab8500_usb_v1x_vbus_fall_irq,
+		IRQF_NO_SUSPEND | IRQF_SHARED,
+		"usb-vbus-fall", ab);
+	if (err < 0) {
+		dev_err(ab->dev, "request_irq failed for Vbus fall irq\n");
+		goto fail3;
+	}
+
+	return 0;
+fail3:
+	free_irq(ab->irq_num_vbus_rise, ab);
+fail2:
+	free_irq(ab->irq_num_id_fall, ab);
+fail1:
+	free_irq(ab->irq_num_id_rise, ab);
+fail0:
+	return err;
+}
+
+static int ab8500_usb_v2_res_setup(struct platform_device *pdev,
+				struct ab8500_usb *ab)
+{
+	int err;
+
+	ab->irq_num_link_status = platform_get_irq_byname(pdev,
+						"USB_LINK_STATUS");
+	if (ab->irq_num_link_status < 0) {
+		dev_err(&pdev->dev, "Link status irq not found\n");
+		return ab->irq_num_link_status;
+	}
+
+	err = request_threaded_irq(ab->irq_num_link_status, NULL,
+		ab8500_usb_v20_irq,
+		IRQF_NO_SUSPEND | IRQF_SHARED,
+		"usb-link-status", ab);
+	if (err < 0) {
+		dev_err(ab->dev,
+			"request_irq failed for link status irq\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static int __devinit ab8500_usb_probe(struct platform_device *pdev)
+{
+	struct ab8500_usb	*ab;
+	int err;
+	int rev;
+
+	rev = abx500_get_chip_id(&pdev->dev);
+	if (rev < 0) {
+		dev_err(&pdev->dev, "Chip id read failed\n");
+		return rev;
+	} else if (rev < 0x10) {
+		dev_err(&pdev->dev, "Unsupported AB8500 chip\n");
+		return -ENODEV;
+	}
+
+	ab = kzalloc(sizeof *ab, GFP_KERNEL);
+	if (!ab)
+		return -ENOMEM;
+
+	ab->dev			= &pdev->dev;
+	ab->rev			= rev;
+	ab->otg.dev		= ab->dev;
+	ab->otg.label		= "ab8500";
+	ab->otg.state		= OTG_STATE_UNDEFINED;
+	ab->otg.set_host	= ab8500_usb_set_host;
+	ab->otg.set_peripheral	= ab8500_usb_set_peripheral;
+	ab->otg.set_suspend	= ab8500_usb_set_suspend;
+	ab->otg.set_power	= ab8500_usb_set_power;
+
+	platform_set_drvdata(pdev, ab);
+
+	BLOCKING_INIT_NOTIFIER_HEAD(&ab->otg.notifier);
+
+	/* v1: Wait for link status to become stable.
+	 * all: Updates form set_host and set_peripheral as they are atomic.
+	 */
+	INIT_DELAYED_WORK(&ab->dwork, ab8500_usb_delayed_work);
+
+	/* all: Disable phy when called from set_host and set_peripheral */
+	INIT_WORK(&ab->phy_dis_work, ab8500_usb_phy_disable_work);
+
+	if (ab->rev < 0x20) {
+		err = ab8500_usb_v1x_res_setup(pdev, ab);
+		ab->link_status_wait = AB8500_V1x_LINK_STAT_WAIT;
+	} else {
+		err = ab8500_usb_v2_res_setup(pdev, ab);
+	}
+
+	if (err < 0)
+		goto fail0;
+
+	err = otg_set_transceiver(&ab->otg);
+	if (err) {
+		dev_err(&pdev->dev, "Can't register transceiver\n");
+		goto fail1;
+	}
+
+	dev_info(&pdev->dev, "AB8500 usb driver initialized\n");
+
+	return 0;
+fail1:
+	ab8500_usb_irq_free(ab);
+fail0:
+	kfree(ab);
+	return err;
+}
+
+static int __devexit ab8500_usb_remove(struct platform_device *pdev)
+{
+	struct ab8500_usb *ab = platform_get_drvdata(pdev);
+
+	ab8500_usb_irq_free(ab);
+
+	cancel_delayed_work_sync(&ab->dwork);
+
+	cancel_work_sync(&ab->phy_dis_work);
+
+	otg_set_transceiver(NULL);
+
+	ab8500_usb_host_phy_dis(ab);
+	ab8500_usb_peri_phy_dis(ab);
+
+	platform_set_drvdata(pdev, NULL);
+
+	kfree(ab);
+
+	return 0;
+}
+
+static struct platform_driver ab8500_usb_driver = {
+	.probe		= ab8500_usb_probe,
+	.remove		= __devexit_p(ab8500_usb_remove),
+	.driver		= {
+		.name	= "ab8500-usb",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init ab8500_usb_init(void)
+{
+	return platform_driver_register(&ab8500_usb_driver);
+}
+subsys_initcall(ab8500_usb_init);
+
+static void __exit ab8500_usb_exit(void)
+{
+	platform_driver_unregister(&ab8500_usb_driver);
+}
+module_exit(ab8500_usb_exit);
+
+MODULE_ALIAS("platform:ab8500_usb");
+MODULE_AUTHOR("ST-Ericsson AB");
+MODULE_DESCRIPTION("AB8500 usb transceiver driver");
+MODULE_LICENSE("GPL");