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linux/drivers/power/isp1704_charger.c
Krzysztof Kozlowski 297d716f62 power_supply: Change ownership from driver to core 
Change the ownership of power_supply structure from each driver
implementing the class to the power supply core.

The patch changes power_supply_register() function thus all drivers
implementing power supply class are adjusted.

Each driver provides the implementation of power supply. However it
should not be the owner of power supply class instance because it is
exposed by core to other subsystems with power_supply_get_by_name().
These other subsystems have no knowledge when the driver will unregister
the power supply. This leads to several issues when driver is unbound -
mostly because user of power supply accesses freed memory.

Instead let the core own the instance of struct 'power_supply'.  Other
users of this power supply will still access valid memory because it
will be freed when device reference count reaches 0. Currently this
means "it will leak" but power_supply_put() call in next patches will
solve it.

This solves invalid memory references in following race condition
scenario:

Thread 1: charger manager
Thread 2: power supply driver, used by charger manager

THREAD 1 (charger manager)         THREAD 2 (power supply driver)
==========================         ==============================
psy = power_supply_get_by_name()
                                   Driver unbind, .remove
                                     power_supply_unregister()
                                     Device fully removed
psy->get_property()

The 'get_property' call is executed in invalid context because the driver was
unbound and struct 'power_supply' memory was freed.

This could be observed easily with charger manager driver (here compiled
with max17040 fuel gauge):

$ cat /sys/devices/virtual/power_supply/cm-battery/capacity &
$ echo "1-0036" > /sys/bus/i2c/drivers/max17040/unbind
[   55.725123] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[   55.732584] pgd = d98d4000
[   55.734060] [00000000] *pgd=5afa2831, *pte=00000000, *ppte=00000000
[   55.740318] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
[   55.746210] Modules linked in:
[   55.749259] CPU: 1 PID: 2936 Comm: cat Tainted: G        W       3.19.0-rc1-next-20141226-00048-gf79f475f3c44-dirty #1496
[   55.760190] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[   55.766270] task: d9b76f00 ti: daf54000 task.ti: daf54000
[   55.771647] PC is at 0x0
[   55.774182] LR is at charger_get_property+0x2f4/0x36c
[   55.779201] pc : [<00000000>]    lr : [<c034b0b4>]    psr: 60000013
[   55.779201] sp : daf55e90  ip : 00000003  fp : 00000000
[   55.790657] r10: 00000000  r9 : c06e2878  r8 : d9b26c68
[   55.795865] r7 : dad81610  r6 : daec7410  r5 : daf55ebc  r4 : 00000000
[   55.802367] r3 : 00000000  r2 : daf55ebc  r1 : 0000002a  r0 : d9b26c68
[   55.808879] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   55.815994] Control: 10c5387d  Table: 598d406a  DAC: 00000015
[   55.821723] Process cat (pid: 2936, stack limit = 0xdaf54210)
[   55.827451] Stack: (0xdaf55e90 to 0xdaf56000)
[   55.831795] 5e80:                                     60000013 c01459c4 0000002a c06f8ef8
[   55.839956] 5ea0: db651000 c06f8ef8 daebac00 c04cb668 daebac08 c0346864 00000000 c01459c4
[   55.848115] 5ec0: d99eaa80 c06f8ef8 00000fff 00001000 db651000 c027f25c c027f240 d99eaa80
[   55.856274] 5ee0: d9a06c00 c0146218 daf55f18 00001000 d99eaa80 db4c18c0 00000001 00000001
[   55.864468] 5f00: daf55f80 c0144c78 c0144c54 c0107f90 00015000 d99eaab0 00000000 00000000
[   55.872603] 5f20: 000051c7 00000000 db4c18c0 c04a9370 00015000 00001000 daf55f80 00001000
[   55.880763] 5f40: daf54000 00015000 00000000 c00e53dc db4c18c0 c00e548c 0000000d 00008124
[   55.888937] 5f60: 00000001 00000000 00000000 db4c18c0 db4c18c0 00001000 00015000 c00e5550
[   55.897099] 5f80: 00000000 00000000 00001000 00001000 00015000 00000003 00000003 c000f364
[   55.905239] 5fa0: 00000000 c000f1a0 00001000 00015000 00000003 00015000 00001000 0001333c
[   55.913399] 5fc0: 00001000 00015000 00000003 00000003 00000002 00000000 00000000 00000000
[   55.921560] 5fe0: 7fffe000 be999850 0000a225 b6f3c19c 60000010 00000003 00000000 00000000
[   55.929744] [<c034b0b4>] (charger_get_property) from [<c0346864>] (power_supply_show_property+0x48/0x20c)
[   55.939286] [<c0346864>] (power_supply_show_property) from [<c027f25c>] (dev_attr_show+0x1c/0x48)
[   55.948130] [<c027f25c>] (dev_attr_show) from [<c0146218>] (sysfs_kf_seq_show+0x84/0x104)
[   55.956298] [<c0146218>] (sysfs_kf_seq_show) from [<c0144c78>] (kernfs_seq_show+0x24/0x28)
[   55.964536] [<c0144c78>] (kernfs_seq_show) from [<c0107f90>] (seq_read+0x1b0/0x484)
[   55.972172] [<c0107f90>] (seq_read) from [<c00e53dc>] (__vfs_read+0x18/0x4c)
[   55.979188] [<c00e53dc>] (__vfs_read) from [<c00e548c>] (vfs_read+0x7c/0x100)
[   55.986304] [<c00e548c>] (vfs_read) from [<c00e5550>] (SyS_read+0x40/0x8c)
[   55.993164] [<c00e5550>] (SyS_read) from [<c000f1a0>] (ret_fast_syscall+0x0/0x48)
[   56.000626] Code: bad PC value
[   56.011652] ---[ end trace 7b64343fbdae8ef1 ]---

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

[for the nvec part]
Reviewed-by: Marc Dietrich <marvin24@gmx.de>

[for compal-laptop.c]
Acked-by: Darren Hart <dvhart@linux.intel.com>

[for the mfd part]
Acked-by: Lee Jones <lee.jones@linaro.org>

[for the hid part]
Acked-by: Jiri Kosina <jkosina@suse.cz>

[for the acpi part]
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-03-13 23:15:51 +01:00

549 lines
14 KiB
C
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/*
* ISP1704 USB Charger Detection driver
*
* Copyright (C) 2010 Nokia Corporation
* Copyright (C) 2012 - 2013 Pali Rohár <pali.rohar@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/sysfs.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/usb/otg.h>
#include <linux/usb/ulpi.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/power/isp1704_charger.h>
/* Vendor specific Power Control register */
#define ISP1704_PWR_CTRL 0x3d
#define ISP1704_PWR_CTRL_SWCTRL (1 << 0)
#define ISP1704_PWR_CTRL_DET_COMP (1 << 1)
#define ISP1704_PWR_CTRL_BVALID_RISE (1 << 2)
#define ISP1704_PWR_CTRL_BVALID_FALL (1 << 3)
#define ISP1704_PWR_CTRL_DP_WKPU_EN (1 << 4)
#define ISP1704_PWR_CTRL_VDAT_DET (1 << 5)
#define ISP1704_PWR_CTRL_DPVSRC_EN (1 << 6)
#define ISP1704_PWR_CTRL_HWDETECT (1 << 7)
#define NXP_VENDOR_ID 0x04cc
static u16 isp170x_id[] = {
0x1704,
0x1707,
};
struct isp1704_charger {
struct device *dev;
struct power_supply *psy;
struct power_supply_desc psy_desc;
struct usb_phy *phy;
struct notifier_block nb;
struct work_struct work;
/* properties */
char model[8];
unsigned present:1;
unsigned online:1;
unsigned current_max;
};
static inline int isp1704_read(struct isp1704_charger *isp, u32 reg)
{
return usb_phy_io_read(isp->phy, reg);
}
static inline int isp1704_write(struct isp1704_charger *isp, u32 val, u32 reg)
{
return usb_phy_io_write(isp->phy, val, reg);
}
/*
* Disable/enable the power from the isp1704 if a function for it
* has been provided with platform data.
*/
static void isp1704_charger_set_power(struct isp1704_charger *isp, bool on)
{
struct isp1704_charger_data *board = isp->dev->platform_data;
if (board && board->set_power)
board->set_power(on);
else if (board)
gpio_set_value(board->enable_gpio, on);
}
/*
* Determine is the charging port DCP (dedicated charger) or CDP (Host/HUB
* chargers).
*
* REVISIT: The method is defined in Battery Charging Specification and is
* applicable to any ULPI transceiver. Nothing isp170x specific here.
*/
static inline int isp1704_charger_type(struct isp1704_charger *isp)
{
u8 reg;
u8 func_ctrl;
u8 otg_ctrl;
int type = POWER_SUPPLY_TYPE_USB_DCP;
func_ctrl = isp1704_read(isp, ULPI_FUNC_CTRL);
otg_ctrl = isp1704_read(isp, ULPI_OTG_CTRL);
/* disable pulldowns */
reg = ULPI_OTG_CTRL_DM_PULLDOWN | ULPI_OTG_CTRL_DP_PULLDOWN;
isp1704_write(isp, ULPI_CLR(ULPI_OTG_CTRL), reg);
/* full speed */
isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
ULPI_FUNC_CTRL_XCVRSEL_MASK);
isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL),
ULPI_FUNC_CTRL_FULL_SPEED);
/* Enable strong pull-up on DP (1.5K) and reset */
reg = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL), reg);
usleep_range(1000, 2000);
reg = isp1704_read(isp, ULPI_DEBUG);
if ((reg & 3) != 3)
type = POWER_SUPPLY_TYPE_USB_CDP;
/* recover original state */
isp1704_write(isp, ULPI_FUNC_CTRL, func_ctrl);
isp1704_write(isp, ULPI_OTG_CTRL, otg_ctrl);
return type;
}
/*
* ISP1704 detects PS/2 adapters as charger. To make sure the detected charger
* is actually a dedicated charger, the following steps need to be taken.
*/
static inline int isp1704_charger_verify(struct isp1704_charger *isp)
{
int ret = 0;
u8 r;
/* Reset the transceiver */
r = isp1704_read(isp, ULPI_FUNC_CTRL);
r |= ULPI_FUNC_CTRL_RESET;
isp1704_write(isp, ULPI_FUNC_CTRL, r);
usleep_range(1000, 2000);
/* Set normal mode */
r &= ~(ULPI_FUNC_CTRL_RESET | ULPI_FUNC_CTRL_OPMODE_MASK);
isp1704_write(isp, ULPI_FUNC_CTRL, r);
/* Clear the DP and DM pull-down bits */
r = ULPI_OTG_CTRL_DP_PULLDOWN | ULPI_OTG_CTRL_DM_PULLDOWN;
isp1704_write(isp, ULPI_CLR(ULPI_OTG_CTRL), r);
/* Enable strong pull-up on DP (1.5K) and reset */
r = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL), r);
usleep_range(1000, 2000);
/* Read the line state */
if (!isp1704_read(isp, ULPI_DEBUG)) {
/* Disable strong pull-up on DP (1.5K) */
isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
ULPI_FUNC_CTRL_TERMSELECT);
return 1;
}
/* Is it a charger or PS/2 connection */
/* Enable weak pull-up resistor on DP */
isp1704_write(isp, ULPI_SET(ISP1704_PWR_CTRL),
ISP1704_PWR_CTRL_DP_WKPU_EN);
/* Disable strong pull-up on DP (1.5K) */
isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
ULPI_FUNC_CTRL_TERMSELECT);
/* Enable weak pull-down resistor on DM */
isp1704_write(isp, ULPI_SET(ULPI_OTG_CTRL),
ULPI_OTG_CTRL_DM_PULLDOWN);
/* It's a charger if the line states are clear */
if (!(isp1704_read(isp, ULPI_DEBUG)))
ret = 1;
/* Disable weak pull-up resistor on DP */
isp1704_write(isp, ULPI_CLR(ISP1704_PWR_CTRL),
ISP1704_PWR_CTRL_DP_WKPU_EN);
return ret;
}
static inline int isp1704_charger_detect(struct isp1704_charger *isp)
{
unsigned long timeout;
u8 pwr_ctrl;
int ret = 0;
pwr_ctrl = isp1704_read(isp, ISP1704_PWR_CTRL);
/* set SW control bit in PWR_CTRL register */
isp1704_write(isp, ISP1704_PWR_CTRL,
ISP1704_PWR_CTRL_SWCTRL);
/* enable manual charger detection */
isp1704_write(isp, ULPI_SET(ISP1704_PWR_CTRL),
ISP1704_PWR_CTRL_SWCTRL
| ISP1704_PWR_CTRL_DPVSRC_EN);
usleep_range(1000, 2000);
timeout = jiffies + msecs_to_jiffies(300);
do {
/* Check if there is a charger */
if (isp1704_read(isp, ISP1704_PWR_CTRL)
& ISP1704_PWR_CTRL_VDAT_DET) {
ret = isp1704_charger_verify(isp);
break;
}
} while (!time_after(jiffies, timeout) && isp->online);
/* recover original state */
isp1704_write(isp, ISP1704_PWR_CTRL, pwr_ctrl);
return ret;
}
static inline int isp1704_charger_detect_dcp(struct isp1704_charger *isp)
{
if (isp1704_charger_detect(isp) &&
isp1704_charger_type(isp) == POWER_SUPPLY_TYPE_USB_DCP)
return true;
else
return false;
}
static void isp1704_charger_work(struct work_struct *data)
{
struct isp1704_charger *isp =
container_of(data, struct isp1704_charger, work);
static DEFINE_MUTEX(lock);
mutex_lock(&lock);
switch (isp->phy->last_event) {
case USB_EVENT_VBUS:
/* do not call wall charger detection more times */
if (!isp->present) {
isp->online = true;
isp->present = 1;
isp1704_charger_set_power(isp, 1);
/* detect wall charger */
if (isp1704_charger_detect_dcp(isp)) {
isp->psy_desc.type = POWER_SUPPLY_TYPE_USB_DCP;
isp->current_max = 1800;
} else {
isp->psy_desc.type = POWER_SUPPLY_TYPE_USB;
isp->current_max = 500;
}
/* enable data pullups */
if (isp->phy->otg->gadget)
usb_gadget_connect(isp->phy->otg->gadget);
}
if (isp->psy_desc.type != POWER_SUPPLY_TYPE_USB_DCP) {
/*
* Only 500mA here or high speed chirp
* handshaking may break
*/
if (isp->current_max > 500)
isp->current_max = 500;
if (isp->current_max > 100)
isp->psy_desc.type = POWER_SUPPLY_TYPE_USB_CDP;
}
break;
case USB_EVENT_NONE:
isp->online = false;
isp->present = 0;
isp->current_max = 0;
isp->psy_desc.type = POWER_SUPPLY_TYPE_USB;
/*
* Disable data pullups. We need to prevent the controller from
* enumerating.
*
* FIXME: This is here to allow charger detection with Host/HUB
* chargers. The pullups may be enabled elsewhere, so this can
* not be the final solution.
*/
if (isp->phy->otg->gadget)
usb_gadget_disconnect(isp->phy->otg->gadget);
isp1704_charger_set_power(isp, 0);
break;
default:
goto out;
}
power_supply_changed(isp->psy);
out:
mutex_unlock(&lock);
}
static int isp1704_notifier_call(struct notifier_block *nb,
unsigned long val, void *v)
{
struct isp1704_charger *isp =
container_of(nb, struct isp1704_charger, nb);
schedule_work(&isp->work);
return NOTIFY_OK;
}
static int isp1704_charger_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct isp1704_charger *isp = power_supply_get_drvdata(psy);
switch (psp) {
case POWER_SUPPLY_PROP_PRESENT:
val->intval = isp->present;
break;
case POWER_SUPPLY_PROP_ONLINE:
val->intval = isp->online;
break;
case POWER_SUPPLY_PROP_CURRENT_MAX:
val->intval = isp->current_max;
break;
case POWER_SUPPLY_PROP_MODEL_NAME:
val->strval = isp->model;
break;
case POWER_SUPPLY_PROP_MANUFACTURER:
val->strval = "NXP";
break;
default:
return -EINVAL;
}
return 0;
}
static enum power_supply_property power_props[] = {
POWER_SUPPLY_PROP_PRESENT,
POWER_SUPPLY_PROP_ONLINE,
POWER_SUPPLY_PROP_CURRENT_MAX,
POWER_SUPPLY_PROP_MODEL_NAME,
POWER_SUPPLY_PROP_MANUFACTURER,
};
static inline int isp1704_test_ulpi(struct isp1704_charger *isp)
{
int vendor;
int product;
int i;
int ret = -ENODEV;
/* Test ULPI interface */
ret = isp1704_write(isp, ULPI_SCRATCH, 0xaa);
if (ret < 0)
return ret;
ret = isp1704_read(isp, ULPI_SCRATCH);
if (ret < 0)
return ret;
if (ret != 0xaa)
return -ENODEV;
/* Verify the product and vendor id matches */
vendor = isp1704_read(isp, ULPI_VENDOR_ID_LOW);
vendor |= isp1704_read(isp, ULPI_VENDOR_ID_HIGH) << 8;
if (vendor != NXP_VENDOR_ID)
return -ENODEV;
product = isp1704_read(isp, ULPI_PRODUCT_ID_LOW);
product |= isp1704_read(isp, ULPI_PRODUCT_ID_HIGH) << 8;
for (i = 0; i < ARRAY_SIZE(isp170x_id); i++) {
if (product == isp170x_id[i]) {
sprintf(isp->model, "isp%x", product);
return product;
}
}
dev_err(isp->dev, "product id %x not matching known ids", product);
return -ENODEV;
}
static int isp1704_charger_probe(struct platform_device *pdev)
{
struct isp1704_charger *isp;
int ret = -ENODEV;
struct power_supply_config psy_cfg = {};
struct isp1704_charger_data *pdata = dev_get_platdata(&pdev->dev);
struct device_node *np = pdev->dev.of_node;
if (np) {
int gpio = of_get_named_gpio(np, "nxp,enable-gpio", 0);
if (gpio < 0)
return gpio;
pdata = devm_kzalloc(&pdev->dev,
sizeof(struct isp1704_charger_data), GFP_KERNEL);
pdata->enable_gpio = gpio;
dev_info(&pdev->dev, "init gpio %d\n", pdata->enable_gpio);
ret = devm_gpio_request_one(&pdev->dev, pdata->enable_gpio,
GPIOF_OUT_INIT_HIGH, "isp1704_reset");
if (ret)
goto fail0;
}
if (!pdata) {
dev_err(&pdev->dev, "missing platform data!\n");
return -ENODEV;
}
isp = devm_kzalloc(&pdev->dev, sizeof(*isp), GFP_KERNEL);
if (!isp)
return -ENOMEM;
if (np)
isp->phy = devm_usb_get_phy_by_phandle(&pdev->dev, "usb-phy", 0);
else
isp->phy = devm_usb_get_phy(&pdev->dev, USB_PHY_TYPE_USB2);
if (IS_ERR(isp->phy)) {
ret = PTR_ERR(isp->phy);
goto fail0;
}
isp->dev = &pdev->dev;
platform_set_drvdata(pdev, isp);
isp1704_charger_set_power(isp, 1);
ret = isp1704_test_ulpi(isp);
if (ret < 0)
goto fail1;
isp->psy_desc.name = "isp1704";
isp->psy_desc.type = POWER_SUPPLY_TYPE_USB;
isp->psy_desc.properties = power_props;
isp->psy_desc.num_properties = ARRAY_SIZE(power_props);
isp->psy_desc.get_property = isp1704_charger_get_property;
psy_cfg.drv_data = isp;
isp->psy = power_supply_register(isp->dev, &isp->psy_desc, &psy_cfg);
if (IS_ERR(isp->psy)) {
ret = PTR_ERR(isp->psy);
goto fail1;
}
/*
* REVISIT: using work in order to allow the usb notifications to be
* made atomically in the future.
*/
INIT_WORK(&isp->work, isp1704_charger_work);
isp->nb.notifier_call = isp1704_notifier_call;
ret = usb_register_notifier(isp->phy, &isp->nb);
if (ret)
goto fail2;
dev_info(isp->dev, "registered with product id %s\n", isp->model);
/*
* Taking over the D+ pullup.
*
* FIXME: The device will be disconnected if it was already
* enumerated. The charger driver should be always loaded before any
* gadget is loaded.
*/
if (isp->phy->otg->gadget)
usb_gadget_disconnect(isp->phy->otg->gadget);
if (isp->phy->last_event == USB_EVENT_NONE)
isp1704_charger_set_power(isp, 0);
/* Detect charger if VBUS is valid (the cable was already plugged). */
if (isp->phy->last_event == USB_EVENT_VBUS &&
!isp->phy->otg->default_a)
schedule_work(&isp->work);
return 0;
fail2:
power_supply_unregister(isp->psy);
fail1:
isp1704_charger_set_power(isp, 0);
fail0:
dev_err(&pdev->dev, "failed to register isp1704 with error %d\n", ret);
return ret;
}
static int isp1704_charger_remove(struct platform_device *pdev)
{
struct isp1704_charger *isp = platform_get_drvdata(pdev);
usb_unregister_notifier(isp->phy, &isp->nb);
power_supply_unregister(isp->psy);
isp1704_charger_set_power(isp, 0);
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id omap_isp1704_of_match[] = {
{ .compatible = "nxp,isp1704", },
{},
};
MODULE_DEVICE_TABLE(of, omap_isp1704_of_match);
#endif
static struct platform_driver isp1704_charger_driver = {
.driver = {
.name = "isp1704_charger",
.of_match_table = of_match_ptr(omap_isp1704_of_match),
},
.probe = isp1704_charger_probe,
.remove = isp1704_charger_remove,
};
module_platform_driver(isp1704_charger_driver);
MODULE_ALIAS("platform:isp1704_charger");
MODULE_AUTHOR("Nokia Corporation");
MODULE_DESCRIPTION("ISP170x USB Charger driver");
MODULE_LICENSE("GPL");
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