/* * 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 unsigned int tahvo_cable[] = { EXTCON_USB, EXTCON_USB_HOST, EXTCON_NONE, }; 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.otg->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.otg->state = OTG_STATE_B_PERIPHERAL; usb_phy_set_event(&tu->phy, USB_EVENT_ENUMERATED); break; case OTG_STATE_A_IDLE: /* * Session is now valid assuming the USB hub is driving * Vbus. */ tu->phy.otg->state = OTG_STATE_A_HOST; break; default: break; } dev_info(&tu->pt_dev->dev, "USB cable connected\n"); } else { switch (tu->phy.otg->state) { case OTG_STATE_B_PERIPHERAL: if (tu->phy.otg->gadget) usb_gadget_vbus_disconnect(tu->phy.otg->gadget); tu->phy.otg->state = OTG_STATE_B_IDLE; usb_phy_set_event(&tu->phy, USB_EVENT_NONE); break; case OTG_STATE_A_HOST: tu->phy.otg->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, 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, 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.otg->state = OTG_STATE_A_IDLE; check_vbus_state(tu); } static void tahvo_usb_stop_host(struct tahvo_usb *tu) { tu->phy.otg->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, 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.otg->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.otg->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.otg->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->usb_phy, struct tahvo_usb, phy); dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host); 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->usb_phy, struct tahvo_usb, phy); dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, gadget); 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 = devm_extcon_dev_allocate(&pdev->dev, tahvo_cable); if (IS_ERR(tu->extcon)) { dev_err(&pdev->dev, "failed to allocate memory for extcon\n"); return -ENOMEM; } ret = devm_extcon_dev_register(&pdev->dev, tu->extcon); 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, EXTCON_USB_HOST, tu->tahvo_mode == TAHVO_MODE_HOST); extcon_set_cable_state_(tu->extcon, EXTCON_USB, tu->vbus_state); /* Create OTG interface */ tahvo_usb_power_off(tu); tu->phy.dev = &pdev->dev; tu->phy.otg->state = OTG_STATE_UNDEFINED; tu->phy.label = DRIVER_NAME; tu->phy.set_suspend = tahvo_usb_set_suspend; tu->phy.otg->usb_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_disable_clk; } dev_set_drvdata(&pdev->dev, tu); tu->irq = platform_get_irq(pdev, 0); ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt, IRQF_ONESHOT, "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_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); 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", }, }; 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@iki.fi>");