Quelle  ehci-atmel.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for EHCI UHP on Atmel chips
 *
 *  Copyright (C) 2009 Atmel Corporation,
 *                     Nicolas Ferre <nicolas.ferre@atmel.com>
 *
 *  Based on various ehci-*.c drivers
 */

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/usb/phy.h>
#include <linux/usb/of.h>

#include "ehci.h"

#define DRIVER_DESC "EHCI Atmel driver"

#define EHCI_INSNREG(index)   ((index) * 4 + 0x90)
#define EHCI_INSNREG08_HSIC_EN   BIT(2)

/* interface and function clocks */
#define hcd_to_atmel_ehci_priv(h) \
 ((struct atmel_ehci_priv *)hcd_to_ehci(h)->priv)

struct atmel_ehci_priv {
 struct clk *iclk;
 struct clk *uclk;
 bool clocked;
};

static struct hc_driver __read_mostly ehci_atmel_hc_driver;

static const struct ehci_driver_overrides ehci_atmel_drv_overrides __initconst = {
 .extra_priv_size = sizeof(struct atmel_ehci_priv),
};

/*-------------------------------------------------------------------------*/

static void atmel_start_clock(struct atmel_ehci_priv *atmel_ehci)
{
 if (atmel_ehci->clocked)
  return;

 clk_prepare_enable(atmel_ehci->uclk);
 clk_prepare_enable(atmel_ehci->iclk);
 atmel_ehci->clocked = true;
}

static void atmel_stop_clock(struct atmel_ehci_priv *atmel_ehci)
{
 if (!atmel_ehci->clocked)
  return;

 clk_disable_unprepare(atmel_ehci->iclk);
 clk_disable_unprepare(atmel_ehci->uclk);
 atmel_ehci->clocked = false;
}

static void atmel_start_ehci(struct platform_device *pdev)
{
 struct usb_hcd *hcd = platform_get_drvdata(pdev);
 struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);

 dev_dbg(&pdev->dev, "start\n");
 atmel_start_clock(atmel_ehci);
}

static void atmel_stop_ehci(struct platform_device *pdev)
{
 struct usb_hcd *hcd = platform_get_drvdata(pdev);
 struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);

 dev_dbg(&pdev->dev, "stop\n");
 atmel_stop_clock(atmel_ehci);
}

/*-------------------------------------------------------------------------*/

static int ehci_atmel_drv_probe(struct platform_device *pdev)
{
 struct usb_hcd *hcd;
 const struct hc_driver *driver = &ehci_atmel_hc_driver;
 struct resource *res;
 struct ehci_hcd *ehci;
 struct atmel_ehci_priv *atmel_ehci;
 int irq;
 int retval;

 if (usb_disabled())
  return -ENODEV;

 pr_debug("Initializing Atmel-SoC USB Host Controller\n");

 irq = platform_get_irq(pdev, 0);
 if (irq < 0) {
  retval = irq;
  goto fail_create_hcd;
 }

 /* Right now device-tree probed devices don't get dma_mask set.
 * Since shared usb code relies on it, set it here for now.
 * Once we have dma capability bindings this can go away.
 */
 retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 if (retval)
  goto fail_create_hcd;

 hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
 if (!hcd) {
  retval = -ENOMEM;
  goto fail_create_hcd;
 }
 atmel_ehci = hcd_to_atmel_ehci_priv(hcd);

 hcd->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
 if (IS_ERR(hcd->regs)) {
  retval = PTR_ERR(hcd->regs);
  goto fail_request_resource;
 }

 hcd->rsrc_start = res->start;
 hcd->rsrc_len = resource_size(res);

 atmel_ehci->iclk = devm_clk_get(&pdev->dev, "ehci_clk");
 if (IS_ERR(atmel_ehci->iclk)) {
  dev_err(&pdev->dev, "Error getting interface clock\n");
  retval = -ENOENT;
  goto fail_request_resource;
 }

 atmel_ehci->uclk = devm_clk_get(&pdev->dev, "usb_clk");
 if (IS_ERR(atmel_ehci->uclk)) {
  dev_err(&pdev->dev, "failed to get uclk\n");
  retval = PTR_ERR(atmel_ehci->uclk);
  goto fail_request_resource;
 }

 ehci = hcd_to_ehci(hcd);
 /* registers start at offset 0x0 */
 ehci->caps = hcd->regs;

 atmel_start_ehci(pdev);

 retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 if (retval)
  goto fail_add_hcd;
 device_wakeup_enable(hcd->self.controller);

 if (of_usb_get_phy_mode(pdev->dev.of_node) == USBPHY_INTERFACE_MODE_HSIC)
  writel(EHCI_INSNREG08_HSIC_EN, hcd->regs + EHCI_INSNREG(8));

 return retval;

fail_add_hcd:
 atmel_stop_ehci(pdev);
fail_request_resource:
 usb_put_hcd(hcd);
fail_create_hcd:
 dev_err(&pdev->dev, "init %s fail, %d\n",
  dev_name(&pdev->dev), retval);

 return retval;
}

static void ehci_atmel_drv_remove(struct platform_device *pdev)
{
 struct usb_hcd *hcd = platform_get_drvdata(pdev);

 usb_remove_hcd(hcd);
 usb_put_hcd(hcd);

 atmel_stop_ehci(pdev);
}

static int __maybe_unused ehci_atmel_drv_suspend(struct device *dev)
{
 struct usb_hcd *hcd = dev_get_drvdata(dev);
 struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
 int ret;

 ret = ehci_suspend(hcd, false);
 if (ret)
  return ret;

 atmel_stop_clock(atmel_ehci);
 return 0;
}

static int __maybe_unused ehci_atmel_drv_resume(struct device *dev)
{
 struct usb_hcd *hcd = dev_get_drvdata(dev);
 struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);

 atmel_start_clock(atmel_ehci);
 ehci_resume(hcd, false);
 return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id atmel_ehci_dt_ids[] = {
 { .compatible = "atmel,at91sam9g45-ehci" },
 { /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
#endif

static SIMPLE_DEV_PM_OPS(ehci_atmel_pm_ops, ehci_atmel_drv_suspend,
     ehci_atmel_drv_resume);

static struct platform_driver ehci_atmel_driver = {
 .probe  = ehci_atmel_drv_probe,
 .remove  = ehci_atmel_drv_remove,
 .shutdown = usb_hcd_platform_shutdown,
 .driver  = {
  .name = "atmel-ehci",
  .pm = &ehci_atmel_pm_ops,
  .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
 },
};

static int __init ehci_atmel_init(void)
{
 if (usb_disabled())
  return -ENODEV;

 ehci_init_driver(&ehci_atmel_hc_driver, &ehci_atmel_drv_overrides);
 return platform_driver_register(&ehci_atmel_driver);
}
module_init(ehci_atmel_init);

static void __exit ehci_atmel_cleanup(void)
{
 platform_driver_unregister(&ehci_atmel_driver);
}
module_exit(ehci_atmel_cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_ALIAS("platform:atmel-ehci");
MODULE_AUTHOR("Nicolas Ferre");
MODULE_LICENSE("GPL");