linux/drivers/mfd/ab8500-sysctrl.c
Linus Walleij 7e9c40c639 mfd: ab8500-sysctrl: Handle probe deferral
In the current boot, clients making use of the AB8500 sysctrl
may be probed before the ab8500-sysctrl driver. This gives them
-EINVAL, but should rather give -EPROBE_DEFER.

Before this, the abx500 clock driver didn't probe properly,
and as a result the codec driver in turn using the clocks did
not probe properly. After this patch, everything probes
properly.

Also add OF compatible-string probing. This driver is all
device tree, so let's just make a drive-by-fix of that as
well.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2017-02-13 09:29:43 +00:00

172 lines
3.6 KiB
C

/*
* AB8500 system control driver
*
* Copyright (C) ST-Ericsson SA 2010
* Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com> for ST Ericsson.
* License terms: GNU General Public License (GPL) version 2
*/
#include <linux/err.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/reboot.h>
#include <linux/signal.h>
#include <linux/power_supply.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/abx500/ab8500.h>
#include <linux/mfd/abx500/ab8500-sysctrl.h>
/* RtcCtrl bits */
#define AB8500_ALARM_MIN_LOW 0x08
#define AB8500_ALARM_MIN_MID 0x09
#define RTC_CTRL 0x0B
#define RTC_ALARM_ENABLE 0x4
static struct device *sysctrl_dev;
static void ab8500_power_off(void)
{
sigset_t old;
sigset_t all;
static const char * const pss[] = {"ab8500_ac", "pm2301", "ab8500_usb"};
int i;
bool charger_present = false;
union power_supply_propval val;
struct power_supply *psy;
int ret;
if (sysctrl_dev == NULL) {
pr_err("%s: sysctrl not initialized\n", __func__);
return;
}
/*
* If we have a charger connected and we're powering off,
* reboot into charge-only mode.
*/
for (i = 0; i < ARRAY_SIZE(pss); i++) {
psy = power_supply_get_by_name(pss[i]);
if (!psy)
continue;
ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_ONLINE,
&val);
power_supply_put(psy);
if (!ret && val.intval) {
charger_present = true;
break;
}
}
if (!charger_present)
goto shutdown;
/* Check if battery is known */
psy = power_supply_get_by_name("ab8500_btemp");
if (psy) {
ret = power_supply_get_property(psy,
POWER_SUPPLY_PROP_TECHNOLOGY, &val);
if (!ret && val.intval != POWER_SUPPLY_TECHNOLOGY_UNKNOWN) {
pr_info("Charger '%s' is connected with known battery",
pss[i]);
pr_info(" - Rebooting.\n");
machine_restart("charging");
}
power_supply_put(psy);
}
shutdown:
sigfillset(&all);
if (!sigprocmask(SIG_BLOCK, &all, &old)) {
(void)ab8500_sysctrl_set(AB8500_STW4500CTRL1,
AB8500_STW4500CTRL1_SWOFF |
AB8500_STW4500CTRL1_SWRESET4500N);
(void)sigprocmask(SIG_SETMASK, &old, NULL);
}
}
static inline bool valid_bank(u8 bank)
{
return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
(bank == AB8500_SYS_CTRL2_BLOCK));
}
int ab8500_sysctrl_read(u16 reg, u8 *value)
{
u8 bank;
if (sysctrl_dev == NULL)
return -EPROBE_DEFER;
bank = (reg >> 8);
if (!valid_bank(bank))
return -EINVAL;
return abx500_get_register_interruptible(sysctrl_dev, bank,
(u8)(reg & 0xFF), value);
}
EXPORT_SYMBOL(ab8500_sysctrl_read);
int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
{
u8 bank;
if (sysctrl_dev == NULL)
return -EPROBE_DEFER;
bank = (reg >> 8);
if (!valid_bank(bank)) {
pr_err("invalid bank\n");
return -EINVAL;
}
return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
(u8)(reg & 0xFF), mask, value);
}
EXPORT_SYMBOL(ab8500_sysctrl_write);
static int ab8500_sysctrl_probe(struct platform_device *pdev)
{
sysctrl_dev = &pdev->dev;
if (!pm_power_off)
pm_power_off = ab8500_power_off;
return 0;
}
static int ab8500_sysctrl_remove(struct platform_device *pdev)
{
sysctrl_dev = NULL;
if (pm_power_off == ab8500_power_off)
pm_power_off = NULL;
return 0;
}
static const struct of_device_id ab8500_sysctrl_match[] = {
{ .compatible = "stericsson,ab8500-sysctrl", },
{}
};
static struct platform_driver ab8500_sysctrl_driver = {
.driver = {
.name = "ab8500-sysctrl",
.of_match_table = ab8500_sysctrl_match,
},
.probe = ab8500_sysctrl_probe,
.remove = ab8500_sysctrl_remove,
};
static int __init ab8500_sysctrl_init(void)
{
return platform_driver_register(&ab8500_sysctrl_driver);
}
arch_initcall(ab8500_sysctrl_init);