linux/drivers/usb/isp1760/isp1760-core.c
Jia-Ju Bai 0f0290089a usb: isp1760: Replace mdelay with msleep in isp1760_init_core
isp1760_init_core() is never called in atomic context.

The call chains ending up at isp1760_init_core() are:
[1] isp1760_init_core() <- isp1760_register() <- isp1760_plat_probe()
[2] isp1760_init_core() <- isp1760_register() <- isp1761_pci_probe()

isp1760_plat_probe() is set as ".probe" in struct platform_driver.
isp1761_pci_probe() is set as ".probe" in struct pci_driver.
These functions are not called in atomic context.

Despite never getting called from atomic context, isp1761_pci_probe()
calls mdelay() to busily wait.
This is not necessary and can be replaced with msleep() to
avoid busy waiting.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-22 15:49:42 +02:00

174 lines
4.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Driver for the NXP ISP1760 chip
*
* Copyright 2014 Laurent Pinchart
* Copyright 2007 Sebastian Siewior
*
* Contacts:
* Sebastian Siewior <bigeasy@linutronix.de>
* Laurent Pinchart <laurent.pinchart@ideasonboard.com>
*/
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include "isp1760-core.h"
#include "isp1760-hcd.h"
#include "isp1760-regs.h"
#include "isp1760-udc.h"
static void isp1760_init_core(struct isp1760_device *isp)
{
u32 otgctrl;
u32 hwmode;
/* Low-level chip reset */
if (isp->rst_gpio) {
gpiod_set_value_cansleep(isp->rst_gpio, 1);
msleep(50);
gpiod_set_value_cansleep(isp->rst_gpio, 0);
}
/*
* Reset the host controller, including the CPU interface
* configuration.
*/
isp1760_write32(isp->regs, HC_RESET_REG, SW_RESET_RESET_ALL);
msleep(100);
/* Setup HW Mode Control: This assumes a level active-low interrupt */
hwmode = HW_DATA_BUS_32BIT;
if (isp->devflags & ISP1760_FLAG_BUS_WIDTH_16)
hwmode &= ~HW_DATA_BUS_32BIT;
if (isp->devflags & ISP1760_FLAG_ANALOG_OC)
hwmode |= HW_ANA_DIGI_OC;
if (isp->devflags & ISP1760_FLAG_DACK_POL_HIGH)
hwmode |= HW_DACK_POL_HIGH;
if (isp->devflags & ISP1760_FLAG_DREQ_POL_HIGH)
hwmode |= HW_DREQ_POL_HIGH;
if (isp->devflags & ISP1760_FLAG_INTR_POL_HIGH)
hwmode |= HW_INTR_HIGH_ACT;
if (isp->devflags & ISP1760_FLAG_INTR_EDGE_TRIG)
hwmode |= HW_INTR_EDGE_TRIG;
/*
* The ISP1761 has a dedicated DC IRQ line but supports sharing the HC
* IRQ line for both the host and device controllers. Hardcode IRQ
* sharing for now and disable the DC interrupts globally to avoid
* spurious interrupts during HCD registration.
*/
if (isp->devflags & ISP1760_FLAG_ISP1761) {
isp1760_write32(isp->regs, DC_MODE, 0);
hwmode |= HW_COMN_IRQ;
}
/*
* We have to set this first in case we're in 16-bit mode.
* Write it twice to ensure correct upper bits if switching
* to 16-bit mode.
*/
isp1760_write32(isp->regs, HC_HW_MODE_CTRL, hwmode);
isp1760_write32(isp->regs, HC_HW_MODE_CTRL, hwmode);
/*
* PORT 1 Control register of the ISP1760 is the OTG control register
* on ISP1761.
*
* TODO: Really support OTG. For now we configure port 1 in device mode
* when OTG is requested.
*/
if ((isp->devflags & ISP1760_FLAG_ISP1761) &&
(isp->devflags & ISP1760_FLAG_OTG_EN))
otgctrl = ((HW_DM_PULLDOWN | HW_DP_PULLDOWN) << 16)
| HW_OTG_DISABLE;
else
otgctrl = (HW_SW_SEL_HC_DC << 16)
| (HW_VBUS_DRV | HW_SEL_CP_EXT);
isp1760_write32(isp->regs, HC_PORT1_CTRL, otgctrl);
dev_info(isp->dev, "bus width: %u, oc: %s\n",
isp->devflags & ISP1760_FLAG_BUS_WIDTH_16 ? 16 : 32,
isp->devflags & ISP1760_FLAG_ANALOG_OC ? "analog" : "digital");
}
void isp1760_set_pullup(struct isp1760_device *isp, bool enable)
{
isp1760_write32(isp->regs, HW_OTG_CTRL_SET,
enable ? HW_DP_PULLUP : HW_DP_PULLUP << 16);
}
int isp1760_register(struct resource *mem, int irq, unsigned long irqflags,
struct device *dev, unsigned int devflags)
{
struct isp1760_device *isp;
bool udc_disabled = !(devflags & ISP1760_FLAG_ISP1761);
int ret;
/*
* If neither the HCD not the UDC is enabled return an error, as no
* device would be registered.
*/
if ((!IS_ENABLED(CONFIG_USB_ISP1760_HCD) || usb_disabled()) &&
(!IS_ENABLED(CONFIG_USB_ISP1761_UDC) || udc_disabled))
return -ENODEV;
/* prevent usb-core allocating DMA pages */
dev->dma_mask = NULL;
isp = devm_kzalloc(dev, sizeof(*isp), GFP_KERNEL);
if (!isp)
return -ENOMEM;
isp->dev = dev;
isp->devflags = devflags;
isp->rst_gpio = devm_gpiod_get_optional(dev, NULL, GPIOD_OUT_HIGH);
if (IS_ERR(isp->rst_gpio))
return PTR_ERR(isp->rst_gpio);
isp->regs = devm_ioremap_resource(dev, mem);
if (IS_ERR(isp->regs))
return PTR_ERR(isp->regs);
isp1760_init_core(isp);
if (IS_ENABLED(CONFIG_USB_ISP1760_HCD) && !usb_disabled()) {
ret = isp1760_hcd_register(&isp->hcd, isp->regs, mem, irq,
irqflags | IRQF_SHARED, dev);
if (ret < 0)
return ret;
}
if (IS_ENABLED(CONFIG_USB_ISP1761_UDC) && !udc_disabled) {
ret = isp1760_udc_register(isp, irq, irqflags);
if (ret < 0) {
isp1760_hcd_unregister(&isp->hcd);
return ret;
}
}
dev_set_drvdata(dev, isp);
return 0;
}
void isp1760_unregister(struct device *dev)
{
struct isp1760_device *isp = dev_get_drvdata(dev);
isp1760_udc_unregister(isp);
isp1760_hcd_unregister(&isp->hcd);
}
MODULE_DESCRIPTION("Driver for the ISP1760 USB-controller from NXP");
MODULE_AUTHOR("Sebastian Siewior <bigeasy@linuxtronix.de>");
MODULE_LICENSE("GPL v2");