blob: 2b10cc969bbb1f4457a463c2072508953a42fdc2 [file] [log] [blame]
/*
* drivers/usb/otg/nop-usb-xceiv.c
*
* 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/otg.h>
#include <linux/usb/nop-usb-xceiv.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/regulator/consumer.h>
#include <linux/of.h>
struct nop_usb_xceiv {
struct usb_phy phy;
struct device *dev;
struct clk *clk;
struct regulator *vcc;
struct regulator *reset;
};
static struct platform_device *pd;
void usb_nop_xceiv_register(void)
{
if (pd)
return;
pd = platform_device_register_simple("nop_usb_xceiv", -1, NULL, 0);
if (!pd) {
printk(KERN_ERR "Unable to register usb nop transceiver\n");
return;
}
}
EXPORT_SYMBOL(usb_nop_xceiv_register);
void usb_nop_xceiv_unregister(void)
{
platform_device_unregister(pd);
pd = NULL;
}
EXPORT_SYMBOL(usb_nop_xceiv_unregister);
static int nop_set_suspend(struct usb_phy *x, int suspend)
{
return 0;
}
static int nop_init(struct usb_phy *phy)
{
struct nop_usb_xceiv *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_enable(nop->clk);
if (!IS_ERR(nop->reset)) {
/* De-assert RESET */
if (regulator_enable(nop->reset))
dev_err(phy->dev, "Failed to de-assert reset\n");
}
return 0;
}
static void nop_shutdown(struct usb_phy *phy)
{
struct nop_usb_xceiv *nop = dev_get_drvdata(phy->dev);
if (!IS_ERR(nop->reset)) {
/* Assert RESET */
if (regulator_disable(nop->reset))
dev_err(phy->dev, "Failed to assert reset\n");
}
if (!IS_ERR(nop->clk))
clk_disable(nop->clk);
if (!IS_ERR(nop->vcc)) {
if (regulator_disable(nop->vcc))
dev_err(phy->dev, "Failed to disable power\n");
}
}
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->phy->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;
}
static int nop_usb_xceiv_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct nop_usb_xceiv_platform_data *pdata = pdev->dev.platform_data;
struct nop_usb_xceiv *nop;
enum usb_phy_type type = USB_PHY_TYPE_USB2;
int err;
u32 clk_rate = 0;
bool needs_vcc = false;
bool needs_reset = false;
nop = devm_kzalloc(&pdev->dev, sizeof(*nop), GFP_KERNEL);
if (!nop)
return -ENOMEM;
nop->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*nop->phy.otg),
GFP_KERNEL);
if (!nop->phy.otg)
return -ENOMEM;
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_reset = of_property_read_bool(node, "reset-supply");
} else if (pdata) {
type = pdata->type;
clk_rate = pdata->clk_rate;
needs_vcc = pdata->needs_vcc;
needs_reset = pdata->needs_reset;
}
nop->clk = devm_clk_get(&pdev->dev, "main_clk");
if (IS_ERR(nop->clk)) {
dev_dbg(&pdev->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(&pdev->dev, "Error setting clock rate\n");
return err;
}
}
if (!IS_ERR(nop->clk)) {
err = clk_prepare(nop->clk);
if (err) {
dev_err(&pdev->dev, "Error preparing clock\n");
return err;
}
}
nop->vcc = devm_regulator_get(&pdev->dev, "vcc");
if (IS_ERR(nop->vcc)) {
dev_dbg(&pdev->dev, "Error getting vcc regulator: %ld\n",
PTR_ERR(nop->vcc));
if (needs_vcc)
return -EPROBE_DEFER;
}
nop->reset = devm_regulator_get(&pdev->dev, "reset");
if (IS_ERR(nop->reset)) {
dev_dbg(&pdev->dev, "Error getting reset regulator: %ld\n",
PTR_ERR(nop->reset));
if (needs_reset)
return -EPROBE_DEFER;
}
nop->dev = &pdev->dev;
nop->phy.dev = nop->dev;
nop->phy.label = "nop-xceiv";
nop->phy.set_suspend = nop_set_suspend;
nop->phy.init = nop_init;
nop->phy.shutdown = nop_shutdown;
nop->phy.state = OTG_STATE_UNDEFINED;
nop->phy.type = type;
nop->phy.otg->phy = &nop->phy;
nop->phy.otg->set_host = nop_set_host;
nop->phy.otg->set_peripheral = nop_set_peripheral;
err = usb_add_phy_dev(&nop->phy);
if (err) {
dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
err);
goto err_add;
}
platform_set_drvdata(pdev, nop);
ATOMIC_INIT_NOTIFIER_HEAD(&nop->phy.notifier);
return 0;
err_add:
if (!IS_ERR(nop->clk))
clk_unprepare(nop->clk);
return err;
}
static int nop_usb_xceiv_remove(struct platform_device *pdev)
{
struct nop_usb_xceiv *nop = platform_get_drvdata(pdev);
if (!IS_ERR(nop->clk))
clk_unprepare(nop->clk);
usb_remove_phy(&nop->phy);
platform_set_drvdata(pdev, NULL);
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 nop_usb_xceiv_driver = {
.probe = nop_usb_xceiv_probe,
.remove = nop_usb_xceiv_remove,
.driver = {
.name = "nop_usb_xceiv",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(nop_xceiv_dt_ids),
},
};
static int __init nop_usb_xceiv_init(void)
{
return platform_driver_register(&nop_usb_xceiv_driver);
}
subsys_initcall(nop_usb_xceiv_init);
static void __exit nop_usb_xceiv_exit(void)
{
platform_driver_unregister(&nop_usb_xceiv_driver);
}
module_exit(nop_usb_xceiv_exit);
MODULE_ALIAS("platform:nop_usb_xceiv");
MODULE_AUTHOR("Texas Instruments Inc");
MODULE_DESCRIPTION("NOP USB Transceiver driver");
MODULE_LICENSE("GPL");