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    Subject[PATCH v4 1/5] usb: host: ehci-st: Add EHCI support for ST STB devices
    Date
    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>
    ---
    drivers/usb/host/ehci-st.c | 363 +++++++++++++++++++++++++++++++++++++++
    drivers/usb/host/usb-st-common.h | 31 ++++
    2 files changed, 394 insertions(+)
    create mode 100644 drivers/usb/host/ehci-st.c
    create mode 100644 drivers/usb/host/usb-st-common.h

    diff --git a/drivers/usb/host/ehci-st.c b/drivers/usb/host/ehci-st.c
    new file mode 100644
    index 0000000..ac72ce3
    --- /dev/null
    +++ b/drivers/usb/host/ehci-st.c
    @@ -0,0 +1,363 @@
    +/*
    + * 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"
    +#include "usb-st-common.h"
    +
    +#define DRIVER_DESC "EHCI STMicroelectronics driver"
    +
    +#define hcd_to_ehci_priv(h) ((struct st_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_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_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_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_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_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
    +
    +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;
    +}
    +
    +#endif /* CONFIG_PM */
    +
    +static SIMPLE_DEV_PM_OPS(st_ehci_pm_ops, st_ehci_suspend, st_ehci_resume);
    +
    +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",
    + .pm = &st_ehci_pm_ops,
    + .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");
    diff --git a/drivers/usb/host/usb-st-common.h b/drivers/usb/host/usb-st-common.h
    new file mode 100644
    index 0000000..da67402
    --- /dev/null
    +++ b/drivers/usb/host/usb-st-common.h
    @@ -0,0 +1,31 @@
    +/*
    + * ST ehci / ohci common header file
    + *
    + * Copyright (C) 2014 STMicroelectronics – All Rights Reserved
    + *
    + * Author: 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 version 2 as
    + * published by the Free Software Foundation.
    + *
    + */
    +
    +#ifndef __USB_ST_COMMON_H
    +#define __USB_ST_COMMON_H
    +
    +#include <linux/clk.h>
    +#include <linux/reset.h>
    +#include <linux/phy/phy.h>
    +
    +#define USB_MAX_CLKS 3
    +
    +struct st_platform_priv {
    + struct clk *clks[USB_MAX_CLKS];
    + struct clk *clk48;
    + struct reset_control *rst;
    + struct reset_control *pwr;
    + struct phy *phy;
    +};
    +
    +#endif /* __USB_ST_COMMON_H */
    --
    1.9.1
    --
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