[PATCH v4 4/4] USB: OMAP1: Tahvo USB transceiver driver
Aaro Koskinen
aaro.koskinen at iki.fi
Fri Dec 6 09:13:07 EST 2013
Add Tahvo USB transceiver driver.
Based on old code from linux-omap tree. The original driver was written
by Juha Yrjölä, Tony Lindgren, and Timo Teräs.
Signed-off-by: Aaro Koskinen <aaro.koskinen at iki.fi>
---
Documentation/ABI/testing/sysfs-platform-tahvo-usb | 16 +
drivers/usb/phy/Kconfig | 15 +
drivers/usb/phy/Makefile | 1 +
drivers/usb/phy/phy-tahvo.c | 461 +++++++++++++++++++++
4 files changed, 493 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-platform-tahvo-usb
create mode 100644 drivers/usb/phy/phy-tahvo.c
diff --git a/Documentation/ABI/testing/sysfs-platform-tahvo-usb b/Documentation/ABI/testing/sysfs-platform-tahvo-usb
new file mode 100644
index 000000000000..f6e20ce4b538
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-platform-tahvo-usb
@@ -0,0 +1,16 @@
+What: /sys/bus/platform/devices/tahvo-usb/otg_mode
+Date: December 2013
+Contact: Aaro Koskinen <aaro.koskinen at iki.fi>
+Description:
+ Set or read the current OTG mode. Valid values are "host" and
+ "peripheral".
+
+ Reading: returns the current mode.
+
+What: /sys/bus/platform/devices/tahvo-usb/vbus
+Date: December 2013
+Contact: Aaro Koskinen <aaro.koskinen at iki.fi>
+Description:
+ Read the current VBUS state.
+
+ Reading: returns "on" or "off".
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index 95d0acc117cc..e0d11c227dd7 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -164,6 +164,21 @@ config OMAP_OTG
This driver can also be built as a module. If so, the module
will be called omap-otg.
+config TAHVO_USB
+ tristate "Tahvo USB transceiver driver"
+ depends on MFD_RETU && EXTCON
+ select USB_PHY
+ help
+ Enable this to support USB transceiver on Tahvo. This is used
+ at least on Nokia 770.
+
+config TAHVO_USB_HOST_BY_DEFAULT
+ depends on TAHVO_USB
+ boolean "Device in USB host mode by default"
+ help
+ Say Y here, if you want the device to enter USB host mode
+ by default on bootup.
+
config USB_ISP1301
tristate "NXP ISP1301 USB transceiver support"
depends on USB || USB_GADGET
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index ca5bcad49da2..5359489891de 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_FSL_USB2_OTG) += phy-fsl-usb2.o
obj-$(CONFIG_ISP1301_OMAP) += phy-isp1301-omap.o
obj-$(CONFIG_MV_U3D_PHY) += phy-mv-u3d-usb.o
obj-$(CONFIG_NOP_USB_XCEIV) += phy-generic.o
+obj-$(CONFIG_TAHVO_USB) += phy-tahvo.o
obj-$(CONFIG_OMAP_CONTROL_USB) += phy-omap-control.o
obj-$(CONFIG_AM335X_CONTROL_USB) += phy-am335x-control.o
obj-$(CONFIG_AM335X_PHY_USB) += phy-am335x.o
diff --git a/drivers/usb/phy/phy-tahvo.c b/drivers/usb/phy/phy-tahvo.c
new file mode 100644
index 000000000000..7cf1766e1106
--- /dev/null
+++ b/drivers/usb/phy/phy-tahvo.c
@@ -0,0 +1,461 @@
+/*
+ * Tahvo USB transceiver driver
+ *
+ * Copyright (C) 2005-2006 Nokia Corporation
+ *
+ * Parts copied from isp1301_omap.c.
+ * Copyright (C) 2004 Texas Instruments
+ * Copyright (C) 2004 David Brownell
+ *
+ * Original driver written by Juha Yrjölä, Tony Lindgren and Timo Teräs.
+ * Modified for Retu/Tahvo MFD by Aaro Koskinen.
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * 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/io.h>
+#include <linux/clk.h>
+#include <linux/usb.h>
+#include <linux/extcon.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/usb/otg.h>
+#include <linux/mfd/retu.h>
+#include <linux/usb/gadget.h>
+#include <linux/platform_device.h>
+
+#define DRIVER_NAME "tahvo-usb"
+
+#define TAHVO_REG_IDSR 0x02
+#define TAHVO_REG_USBR 0x06
+
+#define USBR_SLAVE_CONTROL (1 << 8)
+#define USBR_VPPVIO_SW (1 << 7)
+#define USBR_SPEED (1 << 6)
+#define USBR_REGOUT (1 << 5)
+#define USBR_MASTER_SW2 (1 << 4)
+#define USBR_MASTER_SW1 (1 << 3)
+#define USBR_SLAVE_SW (1 << 2)
+#define USBR_NSUSPEND (1 << 1)
+#define USBR_SEMODE (1 << 0)
+
+#define TAHVO_MODE_HOST 0
+#define TAHVO_MODE_PERIPHERAL 1
+
+struct tahvo_usb {
+ struct platform_device *pt_dev;
+ struct usb_phy phy;
+ int vbus_state;
+ struct mutex serialize;
+ struct clk *ick;
+ int irq;
+ int tahvo_mode;
+ struct extcon_dev extcon;
+};
+
+static const char *tahvo_cable[] = {
+ "USB-HOST",
+ "USB",
+ NULL,
+};
+
+static ssize_t vbus_state_show(struct device *device,
+ struct device_attribute *attr, char *buf)
+{
+ struct tahvo_usb *tu = dev_get_drvdata(device);
+ return sprintf(buf, "%s\n", tu->vbus_state ? "on" : "off");
+}
+static DEVICE_ATTR(vbus, 0444, vbus_state_show, NULL);
+
+static void check_vbus_state(struct tahvo_usb *tu)
+{
+ struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
+ int reg, prev_state;
+
+ reg = retu_read(rdev, TAHVO_REG_IDSR);
+ if (reg & TAHVO_STAT_VBUS) {
+ switch (tu->phy.state) {
+ case OTG_STATE_B_IDLE:
+ /* Enable the gadget driver */
+ if (tu->phy.otg->gadget)
+ usb_gadget_vbus_connect(tu->phy.otg->gadget);
+ tu->phy.state = OTG_STATE_B_PERIPHERAL;
+ break;
+ case OTG_STATE_A_IDLE:
+ /*
+ * Session is now valid assuming the USB hub is driving
+ * Vbus.
+ */
+ tu->phy.state = OTG_STATE_A_HOST;
+ break;
+ default:
+ break;
+ }
+ dev_info(&tu->pt_dev->dev, "USB cable connected\n");
+ } else {
+ switch (tu->phy.state) {
+ case OTG_STATE_B_PERIPHERAL:
+ if (tu->phy.otg->gadget)
+ usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
+ tu->phy.state = OTG_STATE_B_IDLE;
+ break;
+ case OTG_STATE_A_HOST:
+ tu->phy.state = OTG_STATE_A_IDLE;
+ break;
+ default:
+ break;
+ }
+ dev_info(&tu->pt_dev->dev, "USB cable disconnected\n");
+ }
+
+ prev_state = tu->vbus_state;
+ tu->vbus_state = reg & TAHVO_STAT_VBUS;
+ if (prev_state != tu->vbus_state) {
+ extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
+ sysfs_notify(&tu->pt_dev->dev.kobj, NULL, "vbus_state");
+ }
+}
+
+static void tahvo_usb_become_host(struct tahvo_usb *tu)
+{
+ struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
+
+ extcon_set_cable_state(&tu->extcon, "USB-HOST", true);
+
+ /* Power up the transceiver in USB host mode */
+ retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
+ USBR_MASTER_SW2 | USBR_MASTER_SW1);
+ tu->phy.state = OTG_STATE_A_IDLE;
+
+ check_vbus_state(tu);
+}
+
+static void tahvo_usb_stop_host(struct tahvo_usb *tu)
+{
+ tu->phy.state = OTG_STATE_A_IDLE;
+}
+
+static void tahvo_usb_become_peripheral(struct tahvo_usb *tu)
+{
+ struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
+
+ extcon_set_cable_state(&tu->extcon, "USB-HOST", false);
+
+ /* Power up transceiver and set it in USB peripheral mode */
+ retu_write(rdev, TAHVO_REG_USBR, USBR_SLAVE_CONTROL | USBR_REGOUT |
+ USBR_NSUSPEND | USBR_SLAVE_SW);
+ tu->phy.state = OTG_STATE_B_IDLE;
+
+ check_vbus_state(tu);
+}
+
+static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu)
+{
+ if (tu->phy.otg->gadget)
+ usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
+ tu->phy.state = OTG_STATE_B_IDLE;
+}
+
+static void tahvo_usb_power_off(struct tahvo_usb *tu)
+{
+ struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
+
+ /* Disable gadget controller if any */
+ if (tu->phy.otg->gadget)
+ usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
+
+ /* Power off transceiver */
+ retu_write(rdev, TAHVO_REG_USBR, 0);
+ tu->phy.state = OTG_STATE_UNDEFINED;
+}
+
+static int tahvo_usb_set_suspend(struct usb_phy *dev, int suspend)
+{
+ struct tahvo_usb *tu = container_of(dev, struct tahvo_usb, phy);
+ struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
+ u16 w;
+
+ dev_dbg(&tu->pt_dev->dev, "%s\n", __func__);
+
+ w = retu_read(rdev, TAHVO_REG_USBR);
+ if (suspend)
+ w &= ~USBR_NSUSPEND;
+ else
+ w |= USBR_NSUSPEND;
+ retu_write(rdev, TAHVO_REG_USBR, w);
+
+ return 0;
+}
+
+static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
+{
+ struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
+
+ dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
+
+ if (otg == NULL)
+ return -ENODEV;
+
+ mutex_lock(&tu->serialize);
+
+ if (host == NULL) {
+ if (tu->tahvo_mode == TAHVO_MODE_HOST)
+ tahvo_usb_power_off(tu);
+ otg->host = NULL;
+ mutex_unlock(&tu->serialize);
+ return 0;
+ }
+
+ if (tu->tahvo_mode == TAHVO_MODE_HOST) {
+ otg->host = NULL;
+ tahvo_usb_become_host(tu);
+ }
+
+ otg->host = host;
+
+ mutex_unlock(&tu->serialize);
+
+ return 0;
+}
+
+static int tahvo_usb_set_peripheral(struct usb_otg *otg,
+ struct usb_gadget *gadget)
+{
+ struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
+
+ dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, gadget);
+
+ if (!otg)
+ return -ENODEV;
+
+ mutex_lock(&tu->serialize);
+
+ if (!gadget) {
+ if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
+ tahvo_usb_power_off(tu);
+ tu->phy.otg->gadget = NULL;
+ mutex_unlock(&tu->serialize);
+ return 0;
+ }
+
+ tu->phy.otg->gadget = gadget;
+ if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
+ tahvo_usb_become_peripheral(tu);
+
+ mutex_unlock(&tu->serialize);
+
+ return 0;
+}
+
+static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu)
+{
+ struct tahvo_usb *tu = _tu;
+
+ mutex_lock(&tu->serialize);
+ check_vbus_state(tu);
+ mutex_unlock(&tu->serialize);
+
+ return IRQ_HANDLED;
+}
+
+static ssize_t otg_mode_show(struct device *device,
+ struct device_attribute *attr, char *buf)
+{
+ struct tahvo_usb *tu = dev_get_drvdata(device);
+
+ switch (tu->tahvo_mode) {
+ case TAHVO_MODE_HOST:
+ return sprintf(buf, "host\n");
+ case TAHVO_MODE_PERIPHERAL:
+ return sprintf(buf, "peripheral\n");
+ }
+
+ return -EINVAL;
+}
+
+static ssize_t otg_mode_store(struct device *device,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct tahvo_usb *tu = dev_get_drvdata(device);
+ int r;
+
+ mutex_lock(&tu->serialize);
+ if (count >= 4 && strncmp(buf, "host", 4) == 0) {
+ if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
+ tahvo_usb_stop_peripheral(tu);
+ tu->tahvo_mode = TAHVO_MODE_HOST;
+ if (tu->phy.otg->host) {
+ dev_info(device, "HOST mode: host controller present\n");
+ tahvo_usb_become_host(tu);
+ } else {
+ dev_info(device, "HOST mode: no host controller, powering off\n");
+ tahvo_usb_power_off(tu);
+ }
+ r = strlen(buf);
+ } else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) {
+ if (tu->tahvo_mode == TAHVO_MODE_HOST)
+ tahvo_usb_stop_host(tu);
+ tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
+ if (tu->phy.otg->gadget) {
+ dev_info(device, "PERIPHERAL mode: gadget driver present\n");
+ tahvo_usb_become_peripheral(tu);
+ } else {
+ dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n");
+ tahvo_usb_power_off(tu);
+ }
+ r = strlen(buf);
+ } else {
+ r = -EINVAL;
+ }
+ mutex_unlock(&tu->serialize);
+
+ return r;
+}
+static DEVICE_ATTR(otg_mode, 0644, otg_mode_show, otg_mode_store);
+
+static struct attribute *tahvo_attributes[] = {
+ &dev_attr_vbus.attr,
+ &dev_attr_otg_mode.attr,
+ NULL
+};
+
+static struct attribute_group tahvo_attr_group = {
+ .attrs = tahvo_attributes,
+};
+
+static int tahvo_usb_probe(struct platform_device *pdev)
+{
+ struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
+ struct tahvo_usb *tu;
+ int ret;
+
+ tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL);
+ if (!tu)
+ return -ENOMEM;
+
+ tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg),
+ GFP_KERNEL);
+ if (!tu->phy.otg)
+ return -ENOMEM;
+
+ tu->pt_dev = pdev;
+
+ /* Default mode */
+#ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT
+ tu->tahvo_mode = TAHVO_MODE_HOST;
+#else
+ tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
+#endif
+
+ mutex_init(&tu->serialize);
+
+ tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick");
+ if (!IS_ERR(tu->ick))
+ clk_enable(tu->ick);
+
+ /*
+ * Set initial state, so that we generate kevents only on state changes.
+ */
+ tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS;
+
+ tu->extcon.name = DRIVER_NAME;
+ tu->extcon.supported_cable = tahvo_cable;
+ ret = extcon_dev_register(&tu->extcon, &pdev->dev);
+ if (ret) {
+ dev_err(&pdev->dev, "could not register extcon device: %d\n",
+ ret);
+ goto err_disable_clk;
+ }
+
+ /* Set the initial cable state. */
+ extcon_set_cable_state(&tu->extcon, "USB-HOST",
+ tu->tahvo_mode == TAHVO_MODE_HOST);
+ extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
+
+ /* Create OTG interface */
+ tahvo_usb_power_off(tu);
+ tu->phy.dev = &pdev->dev;
+ tu->phy.state = OTG_STATE_UNDEFINED;
+ tu->phy.label = DRIVER_NAME;
+ tu->phy.set_suspend = tahvo_usb_set_suspend;
+
+ tu->phy.otg->phy = &tu->phy;
+ tu->phy.otg->set_host = tahvo_usb_set_host;
+ tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral;
+
+ ret = usb_add_phy(&tu->phy, USB_PHY_TYPE_USB2);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "cannot register USB transceiver: %d\n",
+ ret);
+ goto err_extcon_unreg;
+ }
+
+ dev_set_drvdata(&pdev->dev, tu);
+
+ tu->irq = platform_get_irq(pdev, 0);
+ ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt, 0,
+ "tahvo-vbus", tu);
+ if (ret) {
+ dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n",
+ ret);
+ goto err_remove_phy;
+ }
+
+ /* Attributes */
+ ret = sysfs_create_group(&pdev->dev.kobj, &tahvo_attr_group);
+ if (ret) {
+ dev_err(&pdev->dev, "cannot create sysfs group: %d\n", ret);
+ goto err_free_irq;
+ }
+
+ return 0;
+
+err_free_irq:
+ free_irq(tu->irq, tu);
+err_remove_phy:
+ usb_remove_phy(&tu->phy);
+err_extcon_unreg:
+ extcon_dev_unregister(&tu->extcon);
+err_disable_clk:
+ if (!IS_ERR(tu->ick))
+ clk_disable(tu->ick);
+
+ return ret;
+}
+
+static int tahvo_usb_remove(struct platform_device *pdev)
+{
+ struct tahvo_usb *tu = platform_get_drvdata(pdev);
+
+ sysfs_remove_group(&pdev->dev.kobj, &tahvo_attr_group);
+ free_irq(tu->irq, tu);
+ usb_remove_phy(&tu->phy);
+ extcon_dev_unregister(&tu->extcon);
+ if (!IS_ERR(tu->ick))
+ clk_disable(tu->ick);
+
+ return 0;
+}
+
+static struct platform_driver tahvo_usb_driver = {
+ .probe = tahvo_usb_probe,
+ .remove = tahvo_usb_remove,
+ .driver = {
+ .name = "tahvo-usb",
+ .owner = THIS_MODULE,
+ },
+};
+module_platform_driver(tahvo_usb_driver);
+
+MODULE_DESCRIPTION("Tahvo USB transceiver driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Juha Yrjölä, Tony Lindgren, and Timo Teräs");
+MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen at iki.fi>");
--
1.8.4.4
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