linux/drivers/usb/host/ehci-atmel.c
Manjunath Goudar 9773696105 USB: EHCI: make ehci-atmel a separate driver
Separate the Atmel host controller driver from ehci-hcd host code
so that it can be built as a separate driver module.
This work is part of enabling multi-platform kernels on ARM;
however, note that other changes are still needed before Atmel can be
booted with a multi-platform kernel. This is currently planned for
Linux-3.11.

With the infrastructure added by Alan Stern in patch 3e0232039
"USB: EHCI: prepare to make ehci-hcd a library module", we can
avoid this problem by turning a bus glue into a separate
module, as we do here for the Atmel bus glue.

In V4 (arnd):
 - reordered #include statements.
 - removed call to ehci_shutdown and the corresponding export

In V3:
 - Detailed commit message added here about why this patch is required.
 - Replaced hcd_name string "ehci-atmel" to "atmel-ehci".
 - Inserted blank line in the Makefile to separate the EHCI drivers from
   the following non-EHCI drivers.
 - Exported ehci_shutdown symbol as it is needed by the Atmel driver.
 - Eliminated ehci_atmel_setup routine because hcd registers
   can be directly set in the ehci_atmel_drv_probe function.

In V2:
  Resolved below compiler error.
  drivers/usb/host/ehci-atmel.c: In function 'ehci_atmel_drv_remove':
  drivers/usb/host/ehci-atmel.c:167: error: implicit declaration of function 'ehci_shutdown'

Signed-off-by: Manjunath Goudar <manjunath.goudar@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-08 09:40:20 -07:00

210 lines
4.7 KiB
C

/*
* Driver for EHCI UHP on Atmel chips
*
* Copyright (C) 2009 Atmel Corporation,
* Nicolas Ferre <nicolas.ferre@atmel.com>
*
* Based on various ehci-*.c drivers
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive for
* more details.
*/
#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 "ehci.h"
#define DRIVER_DESC "EHCI Atmel driver"
static const char hcd_name[] = "ehci-atmel";
static struct hc_driver __read_mostly ehci_atmel_hc_driver;
/* interface and function clocks */
static struct clk *iclk, *fclk;
static int clocked;
/*-------------------------------------------------------------------------*/
static void atmel_start_clock(void)
{
clk_enable(iclk);
clk_enable(fclk);
clocked = 1;
}
static void atmel_stop_clock(void)
{
clk_disable(fclk);
clk_disable(iclk);
clocked = 0;
}
static void atmel_start_ehci(struct platform_device *pdev)
{
dev_dbg(&pdev->dev, "start\n");
atmel_start_clock();
}
static void atmel_stop_ehci(struct platform_device *pdev)
{
dev_dbg(&pdev->dev, "stop\n");
atmel_stop_clock();
}
/*-------------------------------------------------------------------------*/
static u64 at91_ehci_dma_mask = DMA_BIT_MASK(32);
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;
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) {
dev_err(&pdev->dev,
"Found HC with no IRQ. Check %s setup!\n",
dev_name(&pdev->dev));
retval = -ENODEV;
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.
*/
if (!pdev->dev.dma_mask)
pdev->dev.dma_mask = &at91_ehci_dma_mask;
hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
if (!hcd) {
retval = -ENOMEM;
goto fail_create_hcd;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev,
"Found HC with no register addr. Check %s setup!\n",
dev_name(&pdev->dev));
retval = -ENODEV;
goto fail_request_resource;
}
hcd->rsrc_start = res->start;
hcd->rsrc_len = resource_size(res);
hcd->regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(hcd->regs)) {
retval = PTR_ERR(hcd->regs);
goto fail_request_resource;
}
iclk = devm_clk_get(&pdev->dev, "ehci_clk");
if (IS_ERR(iclk)) {
dev_err(&pdev->dev, "Error getting interface clock\n");
retval = -ENOENT;
goto fail_request_resource;
}
fclk = devm_clk_get(&pdev->dev, "uhpck");
if (IS_ERR(fclk)) {
dev_err(&pdev->dev, "Error getting function clock\n");
retval = -ENOENT;
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;
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 int 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);
fclk = iclk = NULL;
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 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",
.of_match_table = of_match_ptr(atmel_ehci_dt_ids),
},
};
static int __init ehci_atmel_init(void)
{
if (usb_disabled())
return -ENODEV;
pr_info("%s: " DRIVER_DESC "\n", hcd_name);
ehci_init_driver(&ehci_atmel_hc_driver, NULL);
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");