| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * 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. |
| */ |
| |
| #include <linux/io.h> |
| #include <linux/clk.h> |
| #include <linux/usb.h> |
| #include <linux/extcon-provider.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_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_RO(vbus); |
| |
| 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_state_sync(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_state_sync(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_state_sync(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_RW(otg_mode); |
| |
| static struct attribute *tahvo_attributes[] = { |
| &dev_attr_vbus.attr, |
| &dev_attr_otg_mode.attr, |
| NULL |
| }; |
| |
| static const 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"); |
| ret = PTR_ERR(tu->extcon); |
| goto err_disable_clk; |
| } |
| |
| 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_state_sync(tu->extcon, EXTCON_USB_HOST, |
| tu->tahvo_mode == TAHVO_MODE_HOST); |
| extcon_set_state_sync(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 = ret = platform_get_irq(pdev, 0); |
| if (ret < 0) |
| return ret; |
| 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>"); |