/**
* dwc3-st.c Support for dwc3 platform devices on ST Microelectronics platforms
*
* This is a small driver for the dwc3 to provide the glue logic
* to configure the controller. Tested on STi platforms.
*
* Copyright (C) 2014 Stmicroelectronics
*
* Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
* Contributors: Aymen Bouattay <aymen.bouattay@st.com>
* Peter Griffin <peter.griffin@linaro.org>
*
* 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.
*
* Inspired by dwc3-omap.c and dwc3-exynos.c.
*/
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/pinctrl/consumer.h>
#include <linux/usb/of.h>
#include "core.h"
#include "io.h"
/* glue registers */
#define CLKRST_CTRL 0x00
#define AUX_CLK_EN BIT(0)
#define SW_PIPEW_RESET_N BIT(4)
#define EXT_CFG_RESET_N BIT(8)
/*
* 1'b0 : The host controller complies with the xHCI revision 0.96
* 1'b1 : The host controller complies with the xHCI revision 1.0
*/
#define XHCI_REVISION BIT(12)
#define USB2_VBUS_MNGMNT_SEL1 0x2C
/*
* For all fields in USB2_VBUS_MNGMNT_SEL1
* 2’b00 : Override value from Reg 0x30 is selected
* 2’b01 : utmiotg_<signal_name> from usb3_top is selected
* 2’b10 : pipew_<signal_name> from PIPEW instance is selected
* 2’b11 : value is 1'b0
*/
#define USB2_VBUS_REG30 0x0
#define USB2_VBUS_UTMIOTG 0x1
#define USB2_VBUS_PIPEW 0x2
#define USB2_VBUS_ZERO 0x3
#define SEL_OVERRIDE_VBUSVALID(n) (n << 0)
#define SEL_OVERRIDE_POWERPRESENT(n) (n << 4)
#define SEL_OVERRIDE_BVALID(n) (n << 8)
/* Static DRD configuration */
#define USB3_CONTROL_MASK 0xf77
#define USB3_DEVICE_NOT_HOST BIT(0)
#define USB3_FORCE_VBUSVALID BIT(1)
#define USB3_DELAY_VBUSVALID BIT(2)
#define USB3_SEL_FORCE_OPMODE BIT(4)
#define USB3_FORCE_OPMODE(n) (n << 5)
#define USB3_SEL_FORCE_DPPULLDOWN2 BIT(8)
#define USB3_FORCE_DPPULLDOWN2 BIT(9)
#define USB3_SEL_FORCE_DMPULLDOWN2 BIT(10)
#define USB3_FORCE_DMPULLDOWN2 BIT(11)
/**
* struct st_dwc3 - dwc3-st driver private structure
* @dev: device pointer
* @glue_base: ioaddr for the glue registers
* @regmap: regmap pointer for getting syscfg
* @syscfg_reg_off: usb syscfg control offset
* @dr_mode: drd static host/device config
* @rstc_pwrdn: rest controller for powerdown signal
* @rstc_rst: reset controller for softreset signal
*/
struct st_dwc3 {
struct device *dev;
void __iomem *glue_base;
struct regmap *regmap;
int syscfg_reg_off;
enum usb_dr_mode dr_mode;
struct reset_control *rstc_pwrdn;
struct reset_control *rstc_rst;
};
static inline u32 st_dwc3_readl(void __iomem *base, u32 offset)
{
return readl_relaxed(base + offset);
}
static inline void st_dwc3_writel(void __iomem *base, u32 offset, u32 value)
{
writel_relaxed(value, base + offset);
}
/**
* st_dwc3_drd_init: program the port
* @dwc3_data: driver private structure
* Description: this function is to program the port as either host or device
* according to the static configuration passed from devicetree.
* OTG and dual role are not yet supported!
*/
static int st_dwc3_drd_init(struct st_dwc3 *dwc3_data)
{
u32 val;
int err;
err = regmap_read(dwc3_data->regmap, dwc3_data->syscfg_reg_off, &val);
if (err)
return err;
val &= USB3_CONTROL_MASK;
switch (dwc3_data->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
val &= ~(USB3_DELAY_VBUSVALID
| USB3_SEL_FORCE_OPMODE | USB3_FORCE_OPMODE(0x3)
| USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
| USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
/*
* USB3_PORT2_FORCE_VBUSVALID When '1' and when
* USB3_PORT2_DEVICE_NOT_HOST = 1, forces VBUSVLDEXT2 input
* of the pico PHY to 1.
*/
val |= USB3_DEVICE_NOT_HOST | USB3_FORCE_VBUSVALID;
break;
case USB_DR_MODE_HOST:
val &= ~(USB3_DEVICE_NOT_HOST | USB3_FORCE_VBUSVALID
| USB3_SEL_FORCE_OPMODE | USB3_FORCE_OPMODE(0x3)
| USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
| USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
/*
* USB3_DELAY_VBUSVALID is ANDed with USB_C_VBUSVALID. Thus,
* when set to ‘0‘, it can delay the arrival of VBUSVALID
* information to VBUSVLDEXT2 input of the pico PHY.
* We don't want to do that so we set the bit to '1'.
*/
val |= USB3_DELAY_VBUSVALID;
break;
default:
dev_err(dwc3_data->dev, "Unsupported mode of operation %d\n",
dwc3_data->dr_mode);
return -EINVAL;
}
return regmap_write(dwc3_data->regmap, dwc3_data->syscfg_reg_off, val);
}
/**
* st_dwc3_init: init the controller via glue logic
* @dwc3_data: driver private structure
*/
static void st_dwc3_init(struct st_dwc3 *dwc3_data)
{
u32 reg = st_dwc3_readl(dwc3_data->glue_base, CLKRST_CTRL);
reg |= AUX_CLK_EN | EXT_CFG_RESET_N | XHCI_REVISION;
reg &= ~SW_PIPEW_RESET_N;
st_dwc3_writel(dwc3_data->glue_base, CLKRST_CTRL, reg);
/* configure mux for vbus, powerpresent and bvalid signals */
reg = st_dwc3_readl(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1);
reg |= SEL_OVERRIDE_VBUSVALID(USB2_VBUS_UTMIOTG) |
SEL_OVERRIDE_POWERPRESENT(USB2_VBUS_UTMIOTG) |
SEL_OVERRIDE_BVALID(USB2_VBUS_UTMIOTG);
st_dwc3_writel(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1, reg);
reg = st_dwc3_readl(dwc3_data->glue_base, CLKRST_CTRL);
reg |= SW_PIPEW_RESET_N;
st_dwc3_writel(dwc3_data->glue_base, CLKRST_CTRL, reg);
}
static int st_dwc3_probe(struct platform_device *pdev)
{
struct st_dwc3 *dwc3_data;
struct resource *res;
struct device *dev = &pdev->dev;
struct device_node *node = dev->of_node, *child;
struct platform_device *child_pdev;
struct regmap *regmap;
int ret;
dwc3_data = devm_kzalloc(dev, sizeof(*dwc3_data), GFP_KERNEL);
if (!dwc3_data)
return -ENOMEM;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg-glue");
dwc3_data->glue_base = devm_ioremap_resource(dev, res);
if (IS_ERR(dwc3_data->glue_base))
return PTR_ERR(dwc3_data->glue_base);
regmap = syscon_regmap_lookup_by_phandle(node, "st,syscfg");
if (IS_ERR(regmap))
return PTR_ERR(regmap);
dwc3_data->dev = dev;
dwc3_data->regmap = regmap;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-reg");
if (!res) {
ret = -ENXIO;
goto undo_platform_dev_alloc;
}
dwc3_data->syscfg_reg_off = res->start;
dev_vdbg(&pdev->dev, "glue-logic addr 0x%p, syscfg-reg offset 0x%x\n",
dwc3_data->glue_base, dwc3_data->syscfg_reg_off);
dwc3_data->rstc_pwrdn =
devm_reset_control_get_exclusive(dev, "powerdown");
if (IS_ERR(dwc3_data->rstc_pwrdn)) {
dev_err(&pdev->dev, "could not get power controller\n");
ret = PTR_ERR(dwc3_data->rstc_pwrdn);
goto undo_platform_dev_alloc;
}
/* Manage PowerDown */
reset_control_deassert(dwc3_data->rstc_pwrdn);
dwc3_data->rstc_rst =
devm_reset_control_get_shared(dev, "softreset");
if (IS_ERR(dwc3_data->rstc_rst)) {
dev_err(&pdev->dev, "could not get reset controller\n");
ret = PTR_ERR(dwc3_data->rstc_rst);
goto undo_powerdown;
}
/* Manage SoftReset */
reset_control_deassert(dwc3_data->rstc_rst);
child = of_get_child_by_name(node, "dwc3");
if (!child) {
dev_err(&pdev->dev, "failed to find dwc3 core node\n");
ret = -ENODEV;
goto undo_softreset;
}
/* Allocate and initialize the core */
ret = of_platform_populate(node, NULL, NULL, dev);
if (ret) {
dev_err(dev, "failed to add dwc3 core\n");
goto undo_softreset;
}
child_pdev = of_find_device_by_node(child);
if (!child_pdev) {
dev_err(dev, "failed to find dwc3 core device\n");
ret = -ENODEV;
goto undo_softreset;
}
dwc3_data->dr_mode = usb_get_dr_mode(&child_pdev->dev);
/*
* Configure the USB port as device or host according to the static
* configuration passed from DT.
* DRD is the only mode currently supported so this will be enhanced
* as soon as OTG is available.
*/
ret = st_dwc3_drd_init(dwc3_data);
if (ret) {
dev_err(dev, "drd initialisation failed\n");
goto undo_softreset;
}
/* ST glue logic init */
st_dwc3_init(dwc3_data);
platform_set_drvdata(pdev, dwc3_data);
return 0;
undo_softreset:
reset_control_assert(dwc3_data->rstc_rst);
undo_powerdown:
reset_control_assert(dwc3_data->rstc_pwrdn);
undo_platform_dev_alloc:
platform_device_put(pdev);
return ret;
}
static int st_dwc3_remove(struct platform_device *pdev)
{
struct st_dwc3 *dwc3_data = platform_get_drvdata(pdev);
of_platform_depopulate(&pdev->dev);
reset_control_assert(dwc3_data->rstc_pwrdn);
reset_control_assert(dwc3_data->rstc_rst);
return 0;
}
#ifdef [31mCONFIG_PM_SLEEP[0m
static int st_dwc3_suspend(struct device *dev)
{
struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
reset_control_assert(dwc3_data->rstc_pwrdn);
reset_control_assert(dwc3_data->rstc_rst);
pinctrl_pm_select_sleep_state(dev);
return 0;
}
static int st_dwc3_resume(struct device *dev)
{
struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
int ret;
pinctrl_pm_select_default_state(dev);
reset_control_deassert(dwc3_data->rstc_pwrdn);
reset_control_deassert(dwc3_data->rstc_rst);
ret = st_dwc3_drd_init(dwc3_data);
if (ret) {
dev_err(dev, "drd initialisation failed\n");
return ret;
}
/* ST glue logic init */
st_dwc3_init(dwc3_data);
return 0;
}
#endif /* CONFIG_PM_SLEEP */
static SIMPLE_DEV_PM_OPS(st_dwc3_dev_pm_ops, st_dwc3_suspend, st_dwc3_resume);
static const struct of_device_id st_dwc3_match[] = {
{ .compatible = "st,stih407-dwc3" },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, st_dwc3_match);
static struct platform_driver st_dwc3_driver = {
.probe = st_dwc3_probe,
.remove = st_dwc3_remove,
.driver = {
.name = "usb-st-dwc3",
.of_match_table = st_dwc3_match,
.pm = &st_dwc3_dev_pm_ops,
},
};
module_platform_driver(st_dwc3_driver);
MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
MODULE_DESCRIPTION("DesignWare USB3 STi Glue Layer");
MODULE_LICENSE("GPL v2");