linux/drivers/usb/chipidea/ci13xxx_imx.c
Stephen Warren 3b9561e9d9 USB: set device dma_mask without reference to global data
Many USB host drivers contain code such as:

if (!pdev->dev.dma_mask)
        pdev->dev.dma_mask = &tegra_ehci_dma_mask;

... where tegra_ehci_dma_mask is a global. I suspect this code originated
in commit 4a53f4e "USB: ehci-tegra: add probing through device tree" and
was simply copied everywhere else.

This works fine when the code is built-in, but can cause a crash when the
code is in a module. The first module load sets up the dma_mask pointer,
but if the module is removed and re-inserted, the value is now non-NULL,
and hence is not updated to point at the new location, and hence points
at a stale location within the previous module load address, which in
turn causes a crash if the pointer is de-referenced.

The simplest way of solving this seems to be to copy the code from
ehci-platform.c, which uses the coherent_dma_mask as the target for the
dma_mask pointer.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-16 17:30:52 -07:00

275 lines
6.3 KiB
C

/*
* Copyright 2012 Freescale Semiconductor, Inc.
* Copyright (C) 2012 Marek Vasut <marex@denx.de>
* on behalf of DENX Software Engineering GmbH
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/dma-mapping.h>
#include <linux/usb/chipidea.h>
#include <linux/clk.h>
#include <linux/regulator/consumer.h>
#include <linux/pinctrl/consumer.h>
#include "ci.h"
#include "ci13xxx_imx.h"
#define pdev_to_phy(pdev) \
((struct usb_phy *)platform_get_drvdata(pdev))
struct ci13xxx_imx_data {
struct device_node *phy_np;
struct usb_phy *phy;
struct platform_device *ci_pdev;
struct clk *clk;
struct regulator *reg_vbus;
};
static const struct usbmisc_ops *usbmisc_ops;
/* Common functions shared by usbmisc drivers */
int usbmisc_set_ops(const struct usbmisc_ops *ops)
{
if (usbmisc_ops)
return -EBUSY;
usbmisc_ops = ops;
return 0;
}
EXPORT_SYMBOL_GPL(usbmisc_set_ops);
void usbmisc_unset_ops(const struct usbmisc_ops *ops)
{
usbmisc_ops = NULL;
}
EXPORT_SYMBOL_GPL(usbmisc_unset_ops);
int usbmisc_get_init_data(struct device *dev, struct usbmisc_usb_device *usbdev)
{
struct device_node *np = dev->of_node;
struct of_phandle_args args;
int ret;
usbdev->dev = dev;
ret = of_parse_phandle_with_args(np, "fsl,usbmisc", "#index-cells",
0, &args);
if (ret) {
dev_err(dev, "Failed to parse property fsl,usbmisc, errno %d\n",
ret);
memset(usbdev, 0, sizeof(*usbdev));
return ret;
}
usbdev->index = args.args[0];
of_node_put(args.np);
if (of_find_property(np, "disable-over-current", NULL))
usbdev->disable_oc = 1;
if (of_find_property(np, "external-vbus-divider", NULL))
usbdev->evdo = 1;
return 0;
}
EXPORT_SYMBOL_GPL(usbmisc_get_init_data);
/* End of common functions shared by usbmisc drivers*/
static struct ci13xxx_platform_data ci13xxx_imx_platdata = {
.name = "ci13xxx_imx",
.flags = CI13XXX_REQUIRE_TRANSCEIVER |
CI13XXX_PULLUP_ON_VBUS |
CI13XXX_DISABLE_STREAMING,
.capoffset = DEF_CAPOFFSET,
};
static int ci13xxx_imx_probe(struct platform_device *pdev)
{
struct ci13xxx_imx_data *data;
struct platform_device *plat_ci, *phy_pdev;
struct device_node *phy_np;
struct resource *res;
struct regulator *reg_vbus;
struct pinctrl *pinctrl;
int ret;
if (of_find_property(pdev->dev.of_node, "fsl,usbmisc", NULL)
&& !usbmisc_ops)
return -EPROBE_DEFER;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data) {
dev_err(&pdev->dev, "Failed to allocate CI13xxx-IMX data!\n");
return -ENOMEM;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "Can't get device resources!\n");
return -ENOENT;
}
pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
if (IS_ERR(pinctrl))
dev_warn(&pdev->dev, "pinctrl get/select failed, err=%ld\n",
PTR_ERR(pinctrl));
data->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(data->clk)) {
dev_err(&pdev->dev,
"Failed to get clock, err=%ld\n", PTR_ERR(data->clk));
return PTR_ERR(data->clk);
}
ret = clk_prepare_enable(data->clk);
if (ret) {
dev_err(&pdev->dev,
"Failed to prepare or enable clock, err=%d\n", ret);
return ret;
}
phy_np = of_parse_phandle(pdev->dev.of_node, "fsl,usbphy", 0);
if (phy_np) {
data->phy_np = phy_np;
phy_pdev = of_find_device_by_node(phy_np);
if (phy_pdev) {
struct usb_phy *phy;
phy = pdev_to_phy(phy_pdev);
if (phy &&
try_module_get(phy_pdev->dev.driver->owner)) {
usb_phy_init(phy);
data->phy = phy;
}
}
}
/* we only support host now, so enable vbus here */
reg_vbus = devm_regulator_get(&pdev->dev, "vbus");
if (!IS_ERR(reg_vbus)) {
ret = regulator_enable(reg_vbus);
if (ret) {
dev_err(&pdev->dev,
"Failed to enable vbus regulator, err=%d\n",
ret);
goto put_np;
}
data->reg_vbus = reg_vbus;
} else {
reg_vbus = NULL;
}
ci13xxx_imx_platdata.phy = data->phy;
if (!pdev->dev.dma_mask)
pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
if (!pdev->dev.coherent_dma_mask)
pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
if (usbmisc_ops && usbmisc_ops->init) {
ret = usbmisc_ops->init(&pdev->dev);
if (ret) {
dev_err(&pdev->dev,
"usbmisc init failed, ret=%d\n", ret);
goto err;
}
}
plat_ci = ci13xxx_add_device(&pdev->dev,
pdev->resource, pdev->num_resources,
&ci13xxx_imx_platdata);
if (IS_ERR(plat_ci)) {
ret = PTR_ERR(plat_ci);
dev_err(&pdev->dev,
"Can't register ci_hdrc platform device, err=%d\n",
ret);
goto err;
}
if (usbmisc_ops && usbmisc_ops->post) {
ret = usbmisc_ops->post(&pdev->dev);
if (ret) {
dev_err(&pdev->dev,
"usbmisc post failed, ret=%d\n", ret);
goto put_np;
}
}
data->ci_pdev = plat_ci;
platform_set_drvdata(pdev, data);
pm_runtime_no_callbacks(&pdev->dev);
pm_runtime_enable(&pdev->dev);
return 0;
err:
if (reg_vbus)
regulator_disable(reg_vbus);
put_np:
if (phy_np)
of_node_put(phy_np);
clk_disable_unprepare(data->clk);
return ret;
}
static int ci13xxx_imx_remove(struct platform_device *pdev)
{
struct ci13xxx_imx_data *data = platform_get_drvdata(pdev);
pm_runtime_disable(&pdev->dev);
ci13xxx_remove_device(data->ci_pdev);
if (data->reg_vbus)
regulator_disable(data->reg_vbus);
if (data->phy) {
usb_phy_shutdown(data->phy);
module_put(data->phy->dev->driver->owner);
}
of_node_put(data->phy_np);
clk_disable_unprepare(data->clk);
platform_set_drvdata(pdev, NULL);
return 0;
}
static const struct of_device_id ci13xxx_imx_dt_ids[] = {
{ .compatible = "fsl,imx27-usb", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, ci13xxx_imx_dt_ids);
static struct platform_driver ci13xxx_imx_driver = {
.probe = ci13xxx_imx_probe,
.remove = ci13xxx_imx_remove,
.driver = {
.name = "imx_usb",
.owner = THIS_MODULE,
.of_match_table = ci13xxx_imx_dt_ids,
},
};
module_platform_driver(ci13xxx_imx_driver);
MODULE_ALIAS("platform:imx-usb");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("CI13xxx i.MX USB binding");
MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
MODULE_AUTHOR("Richard Zhao <richard.zhao@freescale.com>");