diff options
Diffstat (limited to 'drivers/usb/phy/phy-generic.c')
| -rw-r--r-- | drivers/usb/phy/phy-generic.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/drivers/usb/phy/phy-generic.c b/drivers/usb/phy/phy-generic.c new file mode 100644 index 000000000..deee68eaf --- /dev/null +++ b/drivers/usb/phy/phy-generic.c @@ -0,0 +1,374 @@ +/* + * 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> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * 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/of_gpio.h> +#include <linux/gpio.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) +{ + return 0; +} + +static void nop_reset(struct usb_phy_generic *nop) +{ + if (!nop->gpiod_reset) + return; + + gpiod_set_value(nop->gpiod_reset, 1); + usleep_range(10000, 20000); + gpiod_set_value(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; + usb_gadget_vbus_connect(otg->gadget); + + /* 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); + + usb_gadget_vbus_disconnect(otg->gadget); + 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); + + if (!IS_ERR(nop->vcc)) { + if (regulator_enable(nop->vcc)) + dev_err(phy->dev, "Failed to enable power\n"); + } + + if (!IS_ERR(nop->clk)) + clk_prepare_enable(nop->clk); + + 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(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; + 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, + struct usb_phy_generic_platform_data *pdata) +{ + enum usb_phy_type type = USB_PHY_TYPE_USB2; + int err = 0; + + u32 clk_rate = 0; + bool needs_vcc = 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"); + nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset"); + err = PTR_ERR_OR_ZERO(nop->gpiod_reset); + if (!err) { + nop->gpiod_vbus = devm_gpiod_get_optional(dev, + "vbus-detect"); + err = PTR_ERR_OR_ZERO(nop->gpiod_vbus); + } + } else if (pdata) { + type = pdata->type; + clk_rate = pdata->clk_rate; + needs_vcc = pdata->needs_vcc; + if (gpio_is_valid(pdata->gpio_reset)) { + err = devm_gpio_request_one(dev, pdata->gpio_reset, 0, + dev_name(dev)); + if (!err) + nop->gpiod_reset = + gpio_to_desc(pdata->gpio_reset); + } + nop->gpiod_vbus = pdata->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 (!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->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, dev_get_platdata(&pdev->dev)); + 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.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"); |