/*
* Copyright (C) 2014 STMicroelectronics
*
* STMicroelectronics Generic PHY driver for STiH407 USB2.
*
* Author: Giuseppe Cavallaro <peppe.cavallaro@st.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/platform_device.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/clk.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/mfd/syscon.h>
#include <linux/phy/phy.h>
/* Default PHY_SEL and REFCLKSEL configuration */
#define STIH407_USB_PICOPHY_CTRL_PORT_CONF 0x6
#define STIH407_USB_PICOPHY_CTRL_PORT_MASK 0x1f
/* ports parameters overriding */
#define STIH407_USB_PICOPHY_PARAM_DEF 0x39a4dc
#define STIH407_USB_PICOPHY_PARAM_MASK 0xffffffff
struct stih407_usb2_picophy {
struct phy *phy;
struct regmap *regmap;
struct device *dev;
struct reset_control *rstc;
struct reset_control *rstport;
int ctrl;
int param;
};
static int stih407_usb2_pico_ctrl(struct stih407_usb2_picophy *phy_dev)
{
reset_control_deassert(phy_dev->rstc);
return regmap_update_bits(phy_dev->regmap, phy_dev->ctrl,
STIH407_USB_PICOPHY_CTRL_PORT_MASK,
STIH407_USB_PICOPHY_CTRL_PORT_CONF);
}
static int stih407_usb2_init_port(struct phy *phy)
{
int ret;
struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
stih407_usb2_pico_ctrl(phy_dev);
ret = regmap_update_bits(phy_dev->regmap,
phy_dev->param,
STIH407_USB_PICOPHY_PARAM_MASK,
STIH407_USB_PICOPHY_PARAM_DEF);
if (ret)
return ret;
return reset_control_deassert(phy_dev->rstport);
}
static int stih407_usb2_exit_port(struct phy *phy)
{
struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
/*
* Only port reset is asserted, phy global reset is kept untouched
* as other ports may still be active. When all ports are in reset
* state, assumption is made that power will be cut off on the phy, in
* case of suspend for instance. Theoretically, asserting individual
* reset (like here) or global reset should be equivalent.
*/
return reset_control_assert(phy_dev->rstport);
}
static const struct phy_ops stih407_usb2_picophy_data = {
.init = stih407_usb2_init_port,
.exit = stih407_usb2_exit_port,
.owner = THIS_MODULE,
};
static int stih407_usb2_picophy_probe(struct platform_device *pdev)
{
struct stih407_usb2_picophy *phy_dev;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct phy_provider *phy_provider;
struct phy *phy;
struct resource *res;
phy_dev = devm_kzalloc(dev, sizeof(*phy_dev), GFP_KERNEL);
if (!phy_dev)
return -ENOMEM;
phy_dev->dev = dev;
dev_set_drvdata(dev, phy_dev);
phy_dev->rstc = devm_reset_control_get(dev, "global");
if (IS_ERR(phy_dev->rstc)) {
dev_err(dev, "failed to ctrl picoPHY reset\n");
return PTR_ERR(phy_dev->rstc);
}
phy_dev->rstport = devm_reset_control_get(dev, "port");
if (IS_ERR(phy_dev->rstport)) {
dev_err(dev, "failed to ctrl picoPHY reset\n");
return PTR_ERR(phy_dev->rstport);
}
/* Reset port by default: only deassert it in phy init */
reset_control_assert(phy_dev->rstport);
phy_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
if (IS_ERR(phy_dev->regmap)) {
dev_err(dev, "No syscfg phandle specified\n");
return PTR_ERR(phy_dev->regmap);
}
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctrl");
if (!res) {
dev_err(dev, "No ctrl reg found\n");
return -ENXIO;
}
phy_dev->ctrl = res->start;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "param");
if (!res) {
dev_err(dev, "No param reg found\n");
return -ENXIO;
}
phy_dev->param = res->start;
phy = devm_phy_create(dev, NULL, &stih407_usb2_picophy_data, NULL);
if (IS_ERR(phy)) {
dev_err(dev, "failed to create Display Port PHY\n");
return PTR_ERR(phy);
}
phy_dev->phy = phy;
phy_set_drvdata(phy, phy_dev);
phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
if (IS_ERR(phy_provider))
return PTR_ERR(phy_provider);
dev_info(dev, "STiH407 USB Generic picoPHY driver probed!");
return 0;
}
static const struct of_device_id stih407_usb2_picophy_of_match[] = {
{ .compatible = "st,stih407-usb2-phy" },
{ /*sentinel */ },
};
MODULE_DEVICE_TABLE(of, stih407_usb2_picophy_of_match);
static struct platform_driver stih407_usb2_picophy_driver = {
.probe = stih407_usb2_picophy_probe,
.driver = {
.name = "stih407-usb-genphy",
.of_match_table = stih407_usb2_picophy_of_match,
}
};
module_platform_driver(stih407_usb2_picophy_driver);
MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
MODULE_DESCRIPTION("STMicroelectronics Generic picoPHY driver for STiH407");
MODULE_LICENSE("GPL v2");
