// SPDX-License-Identifier: GPL-2.0+ /* * NOP USB transceiver for all USB transceiver which are either built-in * into USB IP or which are mostly autonomous. * * Copyright (C) 2009 Texas Instruments Inc * Author: Ajay Kumar Gupta <ajay.gupta@ti.com> * * Current status: * This provides a "nop" transceiver for PHYs which are * autonomous such as isp1504, isp1707, etc. */ #include <linux/module.h> #include <linux/platform_device.h> #include <linux/dma-mapping.h> #include <linux/usb/gadget.h> #include <linux/usb/otg.h> #include <linux/usb/usb_phy_generic.h> #include <linux/slab.h> #include <linux/clk.h> #include <linux/regulator/consumer.h> #include <linux/of.h> #include <linux/gpio/consumer.h> #include <linux/delay.h> #include "phy-generic.h" #define VBUS_IRQ_FLAGS \ (IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | \ IRQF_ONESHOT) struct platform_device *usb_phy_generic_register(void) { return platform_device_register_simple("usb_phy_generic", PLATFORM_DEVID_AUTO, NULL, 0); } EXPORT_SYMBOL_GPL(usb_phy_generic_register); void usb_phy_generic_unregister(struct platform_device *pdev) { platform_device_unregister(pdev); } EXPORT_SYMBOL_GPL(usb_phy_generic_unregister); static int nop_set_suspend(struct usb_phy *x, int suspend) { struct usb_phy_generic *nop = dev_get_drvdata(x->dev); if (!IS_ERR(nop->clk)) { if (suspend) clk_disable_unprepare(nop->clk); else clk_prepare_enable(nop->clk); } return 0; } static void nop_reset(struct usb_phy_generic *nop) { if (!nop->gpiod_reset) return; gpiod_set_value_cansleep(nop->gpiod_reset, 1); usleep_range(10000, 20000); gpiod_set_value_cansleep(nop->gpiod_reset, 0); } /* interface to regulator framework */ static void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA) { struct regulator *vbus_draw = nop->vbus_draw; int enabled; int ret; if (!vbus_draw) return; enabled = nop->vbus_draw_enabled; if (mA) { regulator_set_current_limit(vbus_draw, 0, 1000 * mA); if (!enabled) { ret = regulator_enable(vbus_draw); if (ret < 0) return; nop->vbus_draw_enabled = 1; } } else { if (enabled) { ret = regulator_disable(vbus_draw); if (ret < 0) return; nop->vbus_draw_enabled = 0; } } nop->mA = mA; } static irqreturn_t nop_gpio_vbus_thread(int irq, void *data) { struct usb_phy_generic *nop = data; struct usb_otg *otg = nop->phy.otg; int vbus, status; vbus = gpiod_get_value(nop->gpiod_vbus); if ((vbus ^ nop->vbus) == 0) return IRQ_HANDLED; nop->vbus = vbus; if (vbus) { status = USB_EVENT_VBUS; otg->state = OTG_STATE_B_PERIPHERAL; nop->phy.last_event = status; /* drawing a "unit load" is *always* OK, except for OTG */ nop_set_vbus_draw(nop, 100); atomic_notifier_call_chain(&nop->phy.notifier, status, otg->gadget); } else { nop_set_vbus_draw(nop, 0); status = USB_EVENT_NONE; otg->state = OTG_STATE_B_IDLE; nop->phy.last_event = status; atomic_notifier_call_chain(&nop->phy.notifier, status, otg->gadget); } return IRQ_HANDLED; } int usb_gen_phy_init(struct usb_phy *phy) { struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); int ret; if (!IS_ERR(nop->vcc)) { if (regulator_enable(nop->vcc)) dev_err(phy->dev, "Failed to enable power\n"); } if (!IS_ERR(nop->clk)) { ret = clk_prepare_enable(nop->clk); if (ret) return ret; } nop_reset(nop); return 0; } EXPORT_SYMBOL_GPL(usb_gen_phy_init); void usb_gen_phy_shutdown(struct usb_phy *phy) { struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); gpiod_set_value_cansleep(nop->gpiod_reset, 1); if (!IS_ERR(nop->clk)) clk_disable_unprepare(nop->clk); if (!IS_ERR(nop->vcc)) { if (regulator_disable(nop->vcc)) dev_err(phy->dev, "Failed to disable power\n"); } } EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown); static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget) { if (!otg) return -ENODEV; if (!gadget) { otg->gadget = NULL; return -ENODEV; } otg->gadget = gadget; if (otg->state == OTG_STATE_B_PERIPHERAL) atomic_notifier_call_chain(&otg->usb_phy->notifier, USB_EVENT_VBUS, otg->gadget); else otg->state = OTG_STATE_B_IDLE; return 0; } static int nop_set_host(struct usb_otg *otg, struct usb_bus *host) { if (!otg) return -ENODEV; if (!host) { otg->host = NULL; return -ENODEV; } otg->host = host; return 0; } int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop) { enum usb_phy_type type = USB_PHY_TYPE_USB2; int err = 0; u32 clk_rate = 0; bool needs_vcc = false, needs_clk = false; if (dev->of_node) { struct device_node *node = dev->of_node; if (of_property_read_u32(node, "clock-frequency", &clk_rate)) clk_rate = 0; needs_vcc = of_property_read_bool(node, "vcc-supply"); needs_clk = of_property_read_bool(node, "clocks"); } nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_ASIS); err = PTR_ERR_OR_ZERO(nop->gpiod_reset); if (!err) { nop->gpiod_vbus = devm_gpiod_get_optional(dev, "vbus-detect", GPIOD_ASIS); err = PTR_ERR_OR_ZERO(nop->gpiod_vbus); } if (err == -EPROBE_DEFER) return -EPROBE_DEFER; if (err) { dev_err(dev, "Error requesting RESET or VBUS GPIO\n"); return err; } if (nop->gpiod_reset) gpiod_direction_output(nop->gpiod_reset, 1); nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg), GFP_KERNEL); if (!nop->phy.otg) return -ENOMEM; nop->clk = devm_clk_get(dev, "main_clk"); if (IS_ERR(nop->clk)) { dev_dbg(dev, "Can't get phy clock: %ld\n", PTR_ERR(nop->clk)); if (needs_clk) return PTR_ERR(nop->clk); } if (!IS_ERR(nop->clk) && clk_rate) { err = clk_set_rate(nop->clk, clk_rate); if (err) { dev_err(dev, "Error setting clock rate\n"); return err; } } nop->vcc = devm_regulator_get(dev, "vcc"); if (IS_ERR(nop->vcc)) { dev_dbg(dev, "Error getting vcc regulator: %ld\n", PTR_ERR(nop->vcc)); if (needs_vcc) return -EPROBE_DEFER; } nop->vbus_draw = devm_regulator_get_exclusive(dev, "vbus"); if (PTR_ERR(nop->vbus_draw) == -ENODEV) nop->vbus_draw = NULL; if (IS_ERR(nop->vbus_draw)) return dev_err_probe(dev, PTR_ERR(nop->vbus_draw), "could not get vbus regulator\n"); nop->dev = dev; nop->phy.dev = nop->dev; nop->phy.label = "nop-xceiv"; nop->phy.set_suspend = nop_set_suspend; nop->phy.type = type; nop->phy.otg->state = OTG_STATE_UNDEFINED; nop->phy.otg->usb_phy = &nop->phy; nop->phy.otg->set_host = nop_set_host; nop->phy.otg->set_peripheral = nop_set_peripheral; return 0; } EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy); static int usb_phy_generic_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct usb_phy_generic *nop; int err; nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL); if (!nop) return -ENOMEM; err = usb_phy_gen_create_phy(dev, nop); if (err) return err; if (nop->gpiod_vbus) { err = devm_request_threaded_irq(&pdev->dev, gpiod_to_irq(nop->gpiod_vbus), NULL, nop_gpio_vbus_thread, VBUS_IRQ_FLAGS, "vbus_detect", nop); if (err) { dev_err(&pdev->dev, "can't request irq %i, err: %d\n", gpiod_to_irq(nop->gpiod_vbus), err); return err; } nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ? OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE; } nop->phy.init = usb_gen_phy_init; nop->phy.shutdown = usb_gen_phy_shutdown; err = usb_add_phy_dev(&nop->phy); if (err) { dev_err(&pdev->dev, "can't register transceiver, err: %d\n", err); return err; } platform_set_drvdata(pdev, nop); return 0; } static int usb_phy_generic_remove(struct platform_device *pdev) { struct usb_phy_generic *nop = platform_get_drvdata(pdev); usb_remove_phy(&nop->phy); return 0; } static const struct of_device_id nop_xceiv_dt_ids[] = { { .compatible = "usb-nop-xceiv" }, { } }; MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids); static struct platform_driver usb_phy_generic_driver = { .probe = usb_phy_generic_probe, .remove = usb_phy_generic_remove, .driver = { .name = "usb_phy_generic", .of_match_table = nop_xceiv_dt_ids, }, }; static int __init usb_phy_generic_init(void) { return platform_driver_register(&usb_phy_generic_driver); } subsys_initcall(usb_phy_generic_init); static void __exit usb_phy_generic_exit(void) { platform_driver_unregister(&usb_phy_generic_driver); } module_exit(usb_phy_generic_exit); MODULE_ALIAS("platform:usb_phy_generic"); MODULE_AUTHOR("Texas Instruments Inc"); MODULE_DESCRIPTION("NOP USB Transceiver driver"); MODULE_LICENSE("GPL");