linux/drivers/usb/host/ehci-st.c
Peter Griffin e47c5a0906 usb: host: ehci-st: Add EHCI support for ST STB devices
This patch adds the glue code required to ensure the on-chip EHCI
controller works on STi consumer electronics SoC's from STMicroelectronics.

It mainly manages the setting and enabling of the relevant clocks and manages
the reset / power signals to the IP block.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 21:35:50 -07:00

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/*
* ST EHCI driver
*
* Copyright (C) 2014 STMicroelectronics All Rights Reserved
*
* Author: Peter Griffin <peter.griffin@linaro.org>
*
* Derived from ehci-platform.c
*
* 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/dma-mapping.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/hrtimer.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/usb/ehci_pdriver.h>
#include "ehci.h"
#define USB_MAX_CLKS 3
struct st_ehci_platform_priv {
struct clk *clks[USB_MAX_CLKS];
struct clk *clk48;
struct reset_control *rst;
struct reset_control *pwr;
struct phy *phy;
};
#define DRIVER_DESC "EHCI STMicroelectronics driver"
#define hcd_to_ehci_priv(h) \
((struct st_ehci_platform_priv *)hcd_to_ehci(h)->priv)
static const char hcd_name[] = "ehci-st";
#define EHCI_CAPS_SIZE 0x10
#define AHB2STBUS_INSREG01 (EHCI_CAPS_SIZE + 0x84)
static int st_ehci_platform_reset(struct usb_hcd *hcd)
{
struct platform_device *pdev = to_platform_device(hcd->self.controller);
struct usb_ehci_pdata *pdata = dev_get_platdata(&pdev->dev);
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
int retval;
u32 threshold;
/* Set EHCI packet buffer IN/OUT threshold to 128 bytes */
threshold = 128 | (128 << 16);
writel(threshold, hcd->regs + AHB2STBUS_INSREG01);
ehci->caps = hcd->regs + pdata->caps_offset;
retval = ehci_setup(hcd);
if (retval)
return retval;
return 0;
}
static int st_ehci_platform_power_on(struct platform_device *dev)
{
struct usb_hcd *hcd = platform_get_drvdata(dev);
struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
int clk, ret;
ret = reset_control_deassert(priv->pwr);
if (ret)
return ret;
ret = reset_control_deassert(priv->rst);
if (ret)
goto err_assert_power;
/* some SoCs don't have a dedicated 48Mhz clock, but those that do
need the rate to be explicitly set */
if (priv->clk48) {
ret = clk_set_rate(priv->clk48, 48000000);
if (ret)
goto err_assert_reset;
}
for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++) {
ret = clk_prepare_enable(priv->clks[clk]);
if (ret)
goto err_disable_clks;
}
ret = phy_init(priv->phy);
if (ret)
goto err_disable_clks;
ret = phy_power_on(priv->phy);
if (ret)
goto err_exit_phy;
return 0;
err_exit_phy:
phy_exit(priv->phy);
err_disable_clks:
while (--clk >= 0)
clk_disable_unprepare(priv->clks[clk]);
err_assert_reset:
reset_control_assert(priv->rst);
err_assert_power:
reset_control_assert(priv->pwr);
return ret;
}
static void st_ehci_platform_power_off(struct platform_device *dev)
{
struct usb_hcd *hcd = platform_get_drvdata(dev);
struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
int clk;
reset_control_assert(priv->pwr);
reset_control_assert(priv->rst);
phy_power_off(priv->phy);
phy_exit(priv->phy);
for (clk = USB_MAX_CLKS - 1; clk >= 0; clk--)
if (priv->clks[clk])
clk_disable_unprepare(priv->clks[clk]);
}
static struct hc_driver __read_mostly ehci_platform_hc_driver;
static const struct ehci_driver_overrides platform_overrides __initconst = {
.reset = st_ehci_platform_reset,
.extra_priv_size = sizeof(struct st_ehci_platform_priv),
};
static struct usb_ehci_pdata ehci_platform_defaults = {
.power_on = st_ehci_platform_power_on,
.power_suspend = st_ehci_platform_power_off,
.power_off = st_ehci_platform_power_off,
};
static int st_ehci_platform_probe(struct platform_device *dev)
{
struct usb_hcd *hcd;
struct resource *res_mem;
struct usb_ehci_pdata *pdata = &ehci_platform_defaults;
struct st_ehci_platform_priv *priv;
struct ehci_hcd *ehci;
int err, irq, clk = 0;
if (usb_disabled())
return -ENODEV;
irq = platform_get_irq(dev, 0);
if (irq < 0) {
dev_err(&dev->dev, "no irq provided");
return irq;
}
res_mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
if (!res_mem) {
dev_err(&dev->dev, "no memory resource provided");
return -ENXIO;
}
hcd = usb_create_hcd(&ehci_platform_hc_driver, &dev->dev,
dev_name(&dev->dev));
if (!hcd)
return -ENOMEM;
platform_set_drvdata(dev, hcd);
dev->dev.platform_data = pdata;
priv = hcd_to_ehci_priv(hcd);
ehci = hcd_to_ehci(hcd);
priv->phy = devm_phy_get(&dev->dev, "usb");
if (IS_ERR(priv->phy)) {
err = PTR_ERR(priv->phy);
goto err_put_hcd;
}
for (clk = 0; clk < USB_MAX_CLKS; clk++) {
priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
if (IS_ERR(priv->clks[clk])) {
err = PTR_ERR(priv->clks[clk]);
if (err == -EPROBE_DEFER)
goto err_put_clks;
priv->clks[clk] = NULL;
break;
}
}
/* some SoCs don't have a dedicated 48Mhz clock, but those that
do need the rate to be explicitly set */
priv->clk48 = devm_clk_get(&dev->dev, "clk48");
if (IS_ERR(priv->clk48)) {
dev_info(&dev->dev, "48MHz clk not found\n");
priv->clk48 = NULL;
}
priv->pwr = devm_reset_control_get_optional(&dev->dev, "power");
if (IS_ERR(priv->pwr)) {
err = PTR_ERR(priv->pwr);
if (err == -EPROBE_DEFER)
goto err_put_clks;
priv->pwr = NULL;
}
priv->rst = devm_reset_control_get_optional(&dev->dev, "softreset");
if (IS_ERR(priv->rst)) {
err = PTR_ERR(priv->rst);
if (err == -EPROBE_DEFER)
goto err_put_clks;
priv->rst = NULL;
}
if (pdata->power_on) {
err = pdata->power_on(dev);
if (err < 0)
goto err_put_clks;
}
hcd->rsrc_start = res_mem->start;
hcd->rsrc_len = resource_size(res_mem);
hcd->regs = devm_ioremap_resource(&dev->dev, res_mem);
if (IS_ERR(hcd->regs)) {
err = PTR_ERR(hcd->regs);
goto err_put_clks;
}
err = usb_add_hcd(hcd, irq, IRQF_SHARED);
if (err)
goto err_put_clks;
device_wakeup_enable(hcd->self.controller);
platform_set_drvdata(dev, hcd);
return err;
err_put_clks:
while (--clk >= 0)
clk_put(priv->clks[clk]);
err_put_hcd:
if (pdata == &ehci_platform_defaults)
dev->dev.platform_data = NULL;
usb_put_hcd(hcd);
return err;
}
static int st_ehci_platform_remove(struct platform_device *dev)
{
struct usb_hcd *hcd = platform_get_drvdata(dev);
struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
int clk;
usb_remove_hcd(hcd);
if (pdata->power_off)
pdata->power_off(dev);
for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++)
clk_put(priv->clks[clk]);
usb_put_hcd(hcd);
if (pdata == &ehci_platform_defaults)
dev->dev.platform_data = NULL;
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int st_ehci_suspend(struct device *dev)
{
struct usb_hcd *hcd = dev_get_drvdata(dev);
struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
struct platform_device *pdev =
container_of(dev, struct platform_device, dev);
bool do_wakeup = device_may_wakeup(dev);
int ret;
ret = ehci_suspend(hcd, do_wakeup);
if (ret)
return ret;
if (pdata->power_suspend)
pdata->power_suspend(pdev);
pinctrl_pm_select_sleep_state(dev);
return ret;
}
static int st_ehci_resume(struct device *dev)
{
struct usb_hcd *hcd = dev_get_drvdata(dev);
struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
struct platform_device *pdev =
container_of(dev, struct platform_device, dev);
int err;
pinctrl_pm_select_default_state(dev);
if (pdata->power_on) {
err = pdata->power_on(pdev);
if (err < 0)
return err;
}
ehci_resume(hcd, false);
return 0;
}
static SIMPLE_DEV_PM_OPS(st_ehci_pm_ops, st_ehci_suspend, st_ehci_resume);
#endif /* CONFIG_PM_SLEEP */
static const struct of_device_id st_ehci_ids[] = {
{ .compatible = "st,st-ehci-300x", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, st_ehci_ids);
static struct platform_driver ehci_platform_driver = {
.probe = st_ehci_platform_probe,
.remove = st_ehci_platform_remove,
.shutdown = usb_hcd_platform_shutdown,
.driver = {
.name = "st-ehci",
#ifdef CONFIG_PM_SLEEP
.pm = &st_ehci_pm_ops,
#endif
.of_match_table = st_ehci_ids,
}
};
static int __init ehci_platform_init(void)
{
if (usb_disabled())
return -ENODEV;
pr_info("%s: " DRIVER_DESC "\n", hcd_name);
ehci_init_driver(&ehci_platform_hc_driver, &platform_overrides);
return platform_driver_register(&ehci_platform_driver);
}
module_init(ehci_platform_init);
static void __exit ehci_platform_cleanup(void)
{
platform_driver_unregister(&ehci_platform_driver);
}
module_exit(ehci_platform_cleanup);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Peter Griffin <peter.griffin@linaro.org>");
MODULE_LICENSE("GPL");