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442 lines
11 KiB
442 lines
11 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Tahvo USB transceiver driver |
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* |
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* Copyright (C) 2005-2006 Nokia Corporation |
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* |
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* Parts copied from isp1301_omap.c. |
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* Copyright (C) 2004 Texas Instruments |
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* Copyright (C) 2004 David Brownell |
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* |
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* Original driver written by Juha Yrjölä, Tony Lindgren and Timo Teräs. |
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* Modified for Retu/Tahvo MFD by Aaro Koskinen. |
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*/ |
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#include <linux/io.h> |
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#include <linux/clk.h> |
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#include <linux/usb.h> |
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#include <linux/extcon-provider.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/usb/otg.h> |
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#include <linux/mfd/retu.h> |
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#include <linux/usb/gadget.h> |
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#include <linux/platform_device.h> |
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#define DRIVER_NAME "tahvo-usb" |
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#define TAHVO_REG_IDSR 0x02 |
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#define TAHVO_REG_USBR 0x06 |
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#define USBR_SLAVE_CONTROL (1 << 8) |
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#define USBR_VPPVIO_SW (1 << 7) |
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#define USBR_SPEED (1 << 6) |
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#define USBR_REGOUT (1 << 5) |
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#define USBR_MASTER_SW2 (1 << 4) |
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#define USBR_MASTER_SW1 (1 << 3) |
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#define USBR_SLAVE_SW (1 << 2) |
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#define USBR_NSUSPEND (1 << 1) |
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#define USBR_SEMODE (1 << 0) |
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#define TAHVO_MODE_HOST 0 |
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#define TAHVO_MODE_PERIPHERAL 1 |
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struct tahvo_usb { |
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struct platform_device *pt_dev; |
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struct usb_phy phy; |
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int vbus_state; |
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struct mutex serialize; |
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struct clk *ick; |
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int irq; |
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int tahvo_mode; |
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struct extcon_dev *extcon; |
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}; |
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static const unsigned int tahvo_cable[] = { |
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EXTCON_USB, |
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EXTCON_USB_HOST, |
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EXTCON_NONE, |
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}; |
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static ssize_t vbus_show(struct device *device, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct tahvo_usb *tu = dev_get_drvdata(device); |
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return sprintf(buf, "%s\n", tu->vbus_state ? "on" : "off"); |
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} |
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static DEVICE_ATTR_RO(vbus); |
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static void check_vbus_state(struct tahvo_usb *tu) |
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{ |
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struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent); |
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int reg, prev_state; |
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reg = retu_read(rdev, TAHVO_REG_IDSR); |
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if (reg & TAHVO_STAT_VBUS) { |
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switch (tu->phy.otg->state) { |
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case OTG_STATE_B_IDLE: |
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/* Enable the gadget driver */ |
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if (tu->phy.otg->gadget) |
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usb_gadget_vbus_connect(tu->phy.otg->gadget); |
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tu->phy.otg->state = OTG_STATE_B_PERIPHERAL; |
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usb_phy_set_event(&tu->phy, USB_EVENT_ENUMERATED); |
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break; |
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case OTG_STATE_A_IDLE: |
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/* |
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* Session is now valid assuming the USB hub is driving |
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* Vbus. |
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*/ |
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tu->phy.otg->state = OTG_STATE_A_HOST; |
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break; |
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default: |
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break; |
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} |
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dev_info(&tu->pt_dev->dev, "USB cable connected\n"); |
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} else { |
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switch (tu->phy.otg->state) { |
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case OTG_STATE_B_PERIPHERAL: |
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if (tu->phy.otg->gadget) |
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usb_gadget_vbus_disconnect(tu->phy.otg->gadget); |
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tu->phy.otg->state = OTG_STATE_B_IDLE; |
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usb_phy_set_event(&tu->phy, USB_EVENT_NONE); |
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break; |
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case OTG_STATE_A_HOST: |
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tu->phy.otg->state = OTG_STATE_A_IDLE; |
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break; |
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default: |
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break; |
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} |
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dev_info(&tu->pt_dev->dev, "USB cable disconnected\n"); |
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} |
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prev_state = tu->vbus_state; |
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tu->vbus_state = reg & TAHVO_STAT_VBUS; |
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if (prev_state != tu->vbus_state) { |
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extcon_set_state_sync(tu->extcon, EXTCON_USB, tu->vbus_state); |
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sysfs_notify(&tu->pt_dev->dev.kobj, NULL, "vbus_state"); |
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} |
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} |
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static void tahvo_usb_become_host(struct tahvo_usb *tu) |
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{ |
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struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent); |
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extcon_set_state_sync(tu->extcon, EXTCON_USB_HOST, true); |
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/* Power up the transceiver in USB host mode */ |
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retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND | |
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USBR_MASTER_SW2 | USBR_MASTER_SW1); |
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tu->phy.otg->state = OTG_STATE_A_IDLE; |
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check_vbus_state(tu); |
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} |
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static void tahvo_usb_stop_host(struct tahvo_usb *tu) |
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{ |
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tu->phy.otg->state = OTG_STATE_A_IDLE; |
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} |
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static void tahvo_usb_become_peripheral(struct tahvo_usb *tu) |
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{ |
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struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent); |
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extcon_set_state_sync(tu->extcon, EXTCON_USB_HOST, false); |
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/* Power up transceiver and set it in USB peripheral mode */ |
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retu_write(rdev, TAHVO_REG_USBR, USBR_SLAVE_CONTROL | USBR_REGOUT | |
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USBR_NSUSPEND | USBR_SLAVE_SW); |
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tu->phy.otg->state = OTG_STATE_B_IDLE; |
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check_vbus_state(tu); |
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} |
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static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu) |
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{ |
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if (tu->phy.otg->gadget) |
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usb_gadget_vbus_disconnect(tu->phy.otg->gadget); |
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tu->phy.otg->state = OTG_STATE_B_IDLE; |
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} |
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static void tahvo_usb_power_off(struct tahvo_usb *tu) |
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{ |
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struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent); |
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/* Disable gadget controller if any */ |
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if (tu->phy.otg->gadget) |
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usb_gadget_vbus_disconnect(tu->phy.otg->gadget); |
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/* Power off transceiver */ |
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retu_write(rdev, TAHVO_REG_USBR, 0); |
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tu->phy.otg->state = OTG_STATE_UNDEFINED; |
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} |
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static int tahvo_usb_set_suspend(struct usb_phy *dev, int suspend) |
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{ |
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struct tahvo_usb *tu = container_of(dev, struct tahvo_usb, phy); |
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struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent); |
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u16 w; |
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dev_dbg(&tu->pt_dev->dev, "%s\n", __func__); |
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w = retu_read(rdev, TAHVO_REG_USBR); |
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if (suspend) |
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w &= ~USBR_NSUSPEND; |
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else |
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w |= USBR_NSUSPEND; |
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retu_write(rdev, TAHVO_REG_USBR, w); |
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return 0; |
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} |
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static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host) |
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{ |
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struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb, |
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phy); |
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dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host); |
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mutex_lock(&tu->serialize); |
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if (host == NULL) { |
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if (tu->tahvo_mode == TAHVO_MODE_HOST) |
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tahvo_usb_power_off(tu); |
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otg->host = NULL; |
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mutex_unlock(&tu->serialize); |
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return 0; |
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} |
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if (tu->tahvo_mode == TAHVO_MODE_HOST) { |
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otg->host = NULL; |
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tahvo_usb_become_host(tu); |
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} |
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otg->host = host; |
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mutex_unlock(&tu->serialize); |
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return 0; |
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} |
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static int tahvo_usb_set_peripheral(struct usb_otg *otg, |
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struct usb_gadget *gadget) |
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{ |
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struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb, |
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phy); |
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dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, gadget); |
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mutex_lock(&tu->serialize); |
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if (!gadget) { |
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if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL) |
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tahvo_usb_power_off(tu); |
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tu->phy.otg->gadget = NULL; |
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mutex_unlock(&tu->serialize); |
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return 0; |
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} |
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tu->phy.otg->gadget = gadget; |
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if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL) |
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tahvo_usb_become_peripheral(tu); |
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mutex_unlock(&tu->serialize); |
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return 0; |
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} |
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static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu) |
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{ |
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struct tahvo_usb *tu = _tu; |
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mutex_lock(&tu->serialize); |
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check_vbus_state(tu); |
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mutex_unlock(&tu->serialize); |
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return IRQ_HANDLED; |
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} |
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static ssize_t otg_mode_show(struct device *device, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct tahvo_usb *tu = dev_get_drvdata(device); |
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switch (tu->tahvo_mode) { |
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case TAHVO_MODE_HOST: |
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return sprintf(buf, "host\n"); |
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case TAHVO_MODE_PERIPHERAL: |
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return sprintf(buf, "peripheral\n"); |
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} |
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return -EINVAL; |
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} |
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static ssize_t otg_mode_store(struct device *device, |
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struct device_attribute *attr, |
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const char *buf, size_t count) |
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{ |
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struct tahvo_usb *tu = dev_get_drvdata(device); |
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int r; |
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mutex_lock(&tu->serialize); |
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if (count >= 4 && strncmp(buf, "host", 4) == 0) { |
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if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL) |
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tahvo_usb_stop_peripheral(tu); |
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tu->tahvo_mode = TAHVO_MODE_HOST; |
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if (tu->phy.otg->host) { |
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dev_info(device, "HOST mode: host controller present\n"); |
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tahvo_usb_become_host(tu); |
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} else { |
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dev_info(device, "HOST mode: no host controller, powering off\n"); |
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tahvo_usb_power_off(tu); |
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} |
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r = strlen(buf); |
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} else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) { |
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if (tu->tahvo_mode == TAHVO_MODE_HOST) |
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tahvo_usb_stop_host(tu); |
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tu->tahvo_mode = TAHVO_MODE_PERIPHERAL; |
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if (tu->phy.otg->gadget) { |
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dev_info(device, "PERIPHERAL mode: gadget driver present\n"); |
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tahvo_usb_become_peripheral(tu); |
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} else { |
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dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n"); |
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tahvo_usb_power_off(tu); |
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} |
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r = strlen(buf); |
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} else { |
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r = -EINVAL; |
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} |
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mutex_unlock(&tu->serialize); |
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return r; |
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} |
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static DEVICE_ATTR_RW(otg_mode); |
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static struct attribute *tahvo_attrs[] = { |
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&dev_attr_vbus.attr, |
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&dev_attr_otg_mode.attr, |
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NULL |
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}; |
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ATTRIBUTE_GROUPS(tahvo); |
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static int tahvo_usb_probe(struct platform_device *pdev) |
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{ |
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struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent); |
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struct tahvo_usb *tu; |
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int ret; |
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tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL); |
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if (!tu) |
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return -ENOMEM; |
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tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg), |
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GFP_KERNEL); |
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if (!tu->phy.otg) |
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return -ENOMEM; |
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tu->pt_dev = pdev; |
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/* Default mode */ |
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#ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT |
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tu->tahvo_mode = TAHVO_MODE_HOST; |
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#else |
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tu->tahvo_mode = TAHVO_MODE_PERIPHERAL; |
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#endif |
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mutex_init(&tu->serialize); |
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tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick"); |
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if (!IS_ERR(tu->ick)) |
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clk_enable(tu->ick); |
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/* |
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* Set initial state, so that we generate kevents only on state changes. |
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*/ |
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tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS; |
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tu->extcon = devm_extcon_dev_allocate(&pdev->dev, tahvo_cable); |
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if (IS_ERR(tu->extcon)) { |
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dev_err(&pdev->dev, "failed to allocate memory for extcon\n"); |
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ret = PTR_ERR(tu->extcon); |
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goto err_disable_clk; |
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} |
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ret = devm_extcon_dev_register(&pdev->dev, tu->extcon); |
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if (ret) { |
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dev_err(&pdev->dev, "could not register extcon device: %d\n", |
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ret); |
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goto err_disable_clk; |
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} |
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/* Set the initial cable state. */ |
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extcon_set_state_sync(tu->extcon, EXTCON_USB_HOST, |
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tu->tahvo_mode == TAHVO_MODE_HOST); |
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extcon_set_state_sync(tu->extcon, EXTCON_USB, tu->vbus_state); |
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/* Create OTG interface */ |
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tahvo_usb_power_off(tu); |
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tu->phy.dev = &pdev->dev; |
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tu->phy.otg->state = OTG_STATE_UNDEFINED; |
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tu->phy.label = DRIVER_NAME; |
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tu->phy.set_suspend = tahvo_usb_set_suspend; |
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tu->phy.otg->usb_phy = &tu->phy; |
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tu->phy.otg->set_host = tahvo_usb_set_host; |
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tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral; |
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ret = usb_add_phy(&tu->phy, USB_PHY_TYPE_USB2); |
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if (ret < 0) { |
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dev_err(&pdev->dev, "cannot register USB transceiver: %d\n", |
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ret); |
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goto err_disable_clk; |
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} |
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dev_set_drvdata(&pdev->dev, tu); |
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tu->irq = platform_get_irq(pdev, 0); |
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ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt, |
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IRQF_ONESHOT, |
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"tahvo-vbus", tu); |
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if (ret) { |
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dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n", |
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ret); |
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goto err_remove_phy; |
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} |
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return 0; |
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err_remove_phy: |
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usb_remove_phy(&tu->phy); |
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err_disable_clk: |
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if (!IS_ERR(tu->ick)) |
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clk_disable(tu->ick); |
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return ret; |
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} |
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static int tahvo_usb_remove(struct platform_device *pdev) |
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{ |
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struct tahvo_usb *tu = platform_get_drvdata(pdev); |
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free_irq(tu->irq, tu); |
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usb_remove_phy(&tu->phy); |
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if (!IS_ERR(tu->ick)) |
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clk_disable(tu->ick); |
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return 0; |
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} |
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static struct platform_driver tahvo_usb_driver = { |
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.probe = tahvo_usb_probe, |
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.remove = tahvo_usb_remove, |
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.driver = { |
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.name = "tahvo-usb", |
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.dev_groups = tahvo_groups, |
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}, |
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}; |
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module_platform_driver(tahvo_usb_driver); |
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MODULE_DESCRIPTION("Tahvo USB transceiver driver"); |
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MODULE_LICENSE("GPL"); |
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MODULE_AUTHOR("Juha Yrjölä, Tony Lindgren, and Timo Teräs"); |
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MODULE_AUTHOR("Aaro Koskinen <[email protected]>");
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