phy-lpc18xx-usb-otg.c
/*
* PHY driver for NXP LPC18xx/43xx internal USB OTG PHY
*
* Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
/* USB OTG PHY register offset and bit in CREG */
#define LPC18XX_CREG_CREG0 0x004
#define LPC18XX_CREG_CREG0_USB0PHY BIT(5)
struct lpc18xx_usb_otg_phy {
struct phy *phy;
struct clk *clk;
struct regmap *reg;
};
static int lpc18xx_usb_otg_phy_init(struct phy *phy)
{
struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
int ret;
/* The PHY must be clocked at 480 MHz */
ret = clk_set_rate(lpc->clk, 480000000);
if (ret)
return ret;
return clk_prepare(lpc->clk);
}
static int lpc18xx_usb_otg_phy_exit(struct phy *phy)
{
struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
clk_unprepare(lpc->clk);
return 0;
}
static int lpc18xx_usb_otg_phy_power_on(struct phy *phy)
{
struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
int ret;
ret = clk_enable(lpc->clk);
if (ret)
return ret;
/* The bit in CREG is cleared to enable the PHY */
ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
LPC18XX_CREG_CREG0_USB0PHY, 0);
if (ret) {
clk_disable(lpc->clk);
return ret;
}
return 0;
}
static int lpc18xx_usb_otg_phy_power_off(struct phy *phy)
{
struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
int ret;
ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
LPC18XX_CREG_CREG0_USB0PHY,
LPC18XX_CREG_CREG0_USB0PHY);
if (ret)
return ret;
clk_disable(lpc->clk);
return 0;
}
static const struct phy_ops lpc18xx_usb_otg_phy_ops = {
.init = lpc18xx_usb_otg_phy_init,
.exit = lpc18xx_usb_otg_phy_exit,
.power_on = lpc18xx_usb_otg_phy_power_on,
.power_off = lpc18xx_usb_otg_phy_power_off,
.owner = THIS_MODULE,
};
static int lpc18xx_usb_otg_phy_probe(struct platform_device *pdev)
{
struct phy_provider *phy_provider;
struct lpc18xx_usb_otg_phy *lpc;
lpc = devm_kzalloc(&pdev->dev, sizeof(*lpc), GFP_KERNEL);
if (!lpc)
return -ENOMEM;
lpc->reg = syscon_node_to_regmap(pdev->dev.of_node->parent);
if (IS_ERR(lpc->reg)) {
dev_err(&pdev->dev, "failed to get syscon\n");
return PTR_ERR(lpc->reg);
}
lpc->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(lpc->clk)) {
dev_err(&pdev->dev, "failed to get clock\n");
return PTR_ERR(lpc->clk);
}
lpc->phy = devm_phy_create(&pdev->dev, NULL, &lpc18xx_usb_otg_phy_ops);
if (IS_ERR(lpc->phy)) {
dev_err(&pdev->dev, "failed to create PHY\n");
return PTR_ERR(lpc->phy);
}
phy_set_drvdata(lpc->phy, lpc);
phy_provider = devm_of_phy_provider_register(&pdev->dev,
of_phy_simple_xlate);
return PTR_ERR_OR_ZERO(phy_provider);
}
static const struct of_device_id lpc18xx_usb_otg_phy_match[] = {
{ .compatible = "nxp,lpc1850-usb-otg-phy" },
{ }
};
MODULE_DEVICE_TABLE(of, lpc18xx_usb_otg_phy_match);
static struct platform_driver lpc18xx_usb_otg_phy_driver = {
.probe = lpc18xx_usb_otg_phy_probe,
.driver = {
.name = "lpc18xx-usb-otg-phy",
.of_match_table = lpc18xx_usb_otg_phy_match,
},
};
module_platform_driver(lpc18xx_usb_otg_phy_driver);
MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
MODULE_DESCRIPTION("NXP LPC18xx/43xx USB OTG PHY driver");
MODULE_LICENSE("GPL v2");