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rtc-ds1307.c: add DT property 'wakeup-source' #1260

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rtc-ds1307.c: add DT property 'wakeup-source' #1260

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1f37803
dt-overlay: add wittypi-overlay.dts
Jan 19, 2016
1529b92
rtc-ds1307.c: backport from linux-4.4
Jan 19, 2016
ba4b898
rtc-ds1307.c: add DT property 'wakeup-source' to indicate the rtc can…
Jan 19, 2016
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44 changes: 44 additions & 0 deletions arch/arm/boot/dts/overlays/wittypi-overlay.dts
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Original file line number Diff line number Diff line change
@@ -0,0 +1,44 @@
/*
* Device Tree overlay for Witty Pi extension board by UUGear
*
*/

/dts-v1/;
/plugin/;

/ {

compatible = "brcm,bcm2835", "brcm,bcm2708", "brcm,bcm2709";

fragment@0 {
target = <&leds>;
__overlay__ {
compatible = "gpio-leds";
wittypi_led: wittypi_led {
label = "wittypi_led";
linux,default-trigger = "default-on";
gpios = <&gpio 17 0>;
};
};
};

fragment@1 {
target = <&i2c1>;
__overlay__ {
#address-cells = <1>;
#size-cells = <0>;

rtc: ds1337@68 {
compatible = "dallas,ds1337";
reg = <0x68>;
wakeup-source;
};
};
};

__overrides__ {
led_gpio = <&wittypi_led>,"gpios:4";
led_trigger = <&wittypi_led>,"linux,default-trigger";
};

};
141 changes: 65 additions & 76 deletions drivers/rtc/rtc-ds1307.c
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Original file line number Diff line number Diff line change
Expand Up @@ -11,14 +11,14 @@
* published by the Free Software Foundation.
*/

#include <linux/module.h>
#include <linux/bcd.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/rtc/ds1307.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/string.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/rtc/ds1307.h>

/*
* We can't determine type by probing, but if we expect pre-Linux code
Expand Down Expand Up @@ -114,7 +114,6 @@ struct ds1307 {
#define HAS_ALARM 1 /* bit 1 == irq claimed */
struct i2c_client *client;
struct rtc_device *rtc;
struct work_struct work;
s32 (*read_block_data)(const struct i2c_client *client, u8 command,
u8 length, u8 *values);
s32 (*write_block_data)(const struct i2c_client *client, u8 command,
Expand Down Expand Up @@ -311,27 +310,17 @@ static s32 ds1307_native_smbus_read_block_data(const struct i2c_client *client,
/*----------------------------------------------------------------------*/

/*
* The IRQ logic includes a "real" handler running in IRQ context just
* long enough to schedule this workqueue entry. We need a task context
* to talk to the RTC, since I2C I/O calls require that; and disable the
* IRQ until we clear its status on the chip, so that this handler can
* work with any type of triggering (not just falling edge).
*
* The ds1337 and ds1339 both have two alarms, but we only use the first
* one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
* signal; ds1339 chips have only one alarm signal.
*/
static void ds1307_work(struct work_struct *work)
static irqreturn_t ds1307_irq(int irq, void *dev_id)
{
struct ds1307 *ds1307;
struct i2c_client *client;
struct mutex *lock;
struct i2c_client *client = dev_id;
struct ds1307 *ds1307 = i2c_get_clientdata(client);
struct mutex *lock = &ds1307->rtc->ops_lock;
int stat, control;

ds1307 = container_of(work, struct ds1307, work);
client = ds1307->client;
lock = &ds1307->rtc->ops_lock;

mutex_lock(lock);
stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
if (stat < 0)
Expand All @@ -352,18 +341,8 @@ static void ds1307_work(struct work_struct *work)
}

out:
if (test_bit(HAS_ALARM, &ds1307->flags))
enable_irq(client->irq);
mutex_unlock(lock);
}

static irqreturn_t ds1307_irq(int irq, void *dev_id)
{
struct i2c_client *client = dev_id;
struct ds1307 *ds1307 = i2c_get_clientdata(client);

disable_irq_nosync(irq);
schedule_work(&ds1307->work);
return IRQ_HANDLED;
}

Expand Down Expand Up @@ -634,13 +613,14 @@ static const struct rtc_class_ops ds13xx_rtc_ops = {
MCP794XX_BIT_ALMX_C1 | \
MCP794XX_BIT_ALMX_C2)

static void mcp794xx_work(struct work_struct *work)
static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
{
struct ds1307 *ds1307 = container_of(work, struct ds1307, work);
struct i2c_client *client = ds1307->client;
struct i2c_client *client = dev_id;
struct ds1307 *ds1307 = i2c_get_clientdata(client);
struct mutex *lock = &ds1307->rtc->ops_lock;
int reg, ret;

mutex_lock(&ds1307->rtc->ops_lock);
mutex_lock(lock);

/* Check and clear alarm 0 interrupt flag. */
reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_ALARM0_CTRL);
Expand All @@ -665,9 +645,9 @@ static void mcp794xx_work(struct work_struct *work)
rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);

out:
if (test_bit(HAS_ALARM, &ds1307->flags))
enable_irq(client->irq);
mutex_unlock(&ds1307->rtc->ops_lock);
mutex_unlock(lock);

return IRQ_HANDLED;
}

static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
Expand Down Expand Up @@ -734,25 +714,25 @@ static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
regs[3] = bin2bcd(t->time.tm_sec);
regs[4] = bin2bcd(t->time.tm_min);
regs[5] = bin2bcd(t->time.tm_hour);
regs[6] = bin2bcd(t->time.tm_wday) + 1;
regs[6] = bin2bcd(t->time.tm_wday + 1);
regs[7] = bin2bcd(t->time.tm_mday);
regs[8] = bin2bcd(t->time.tm_mon) + 1;
regs[8] = bin2bcd(t->time.tm_mon + 1);

/* Clear the alarm 0 interrupt flag. */
regs[6] &= ~MCP794XX_BIT_ALMX_IF;
/* Set alarm match: second, minute, hour, day, date, month. */
regs[6] |= MCP794XX_MSK_ALMX_MATCH;

if (t->enabled)
regs[0] |= MCP794XX_BIT_ALM0_EN;
else
regs[0] &= ~MCP794XX_BIT_ALM0_EN;
/* Disable interrupt. We will not enable until completely programmed */
regs[0] &= ~MCP794XX_BIT_ALM0_EN;

ret = ds1307->write_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
if (ret < 0)
return ret;

return 0;
if (!t->enabled)
return 0;
regs[0] |= MCP794XX_BIT_ALM0_EN;
return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, regs[0]);
}

static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
Expand Down Expand Up @@ -798,13 +778,6 @@ ds1307_nvram_read(struct file *filp, struct kobject *kobj,
client = kobj_to_i2c_client(kobj);
ds1307 = i2c_get_clientdata(client);

if (unlikely(off >= ds1307->nvram->size))
return 0;
if ((off + count) > ds1307->nvram->size)
count = ds1307->nvram->size - off;
if (unlikely(!count))
return count;

result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
count, buf);
if (result < 0)
Expand All @@ -824,13 +797,6 @@ ds1307_nvram_write(struct file *filp, struct kobject *kobj,
client = kobj_to_i2c_client(kobj);
ds1307 = i2c_get_clientdata(client);

if (unlikely(off >= ds1307->nvram->size))
return -EFBIG;
if ((off + count) > ds1307->nvram->size)
count = ds1307->nvram->size - off;
if (unlikely(!count))
return count;

result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
count, buf);
if (result < 0) {
Expand Down Expand Up @@ -894,8 +860,11 @@ static int ds1307_probe(struct i2c_client *client,
struct chip_desc *chip = &chips[id->driver_data];
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
bool want_irq = false;
bool ds1307_can_wakeup_device = false;
unsigned char *buf;
struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
irq_handler_t irq_handler = ds1307_irq;

static const int bbsqi_bitpos[] = {
[ds_1337] = 0,
[ds_1339] = DS1339_BIT_BBSQI,
Expand Down Expand Up @@ -939,6 +908,20 @@ static int ds1307_probe(struct i2c_client *client,
ds1307->write_block_data = ds1307_write_block_data;
}

#ifdef CONFIG_OF
/*
* For devices with no IRQ directly connected to the SoC, the RTC chip
* can be forced as a wakeup source by stating that explicitly in
* the device's .dts file using the "wakeup-source" boolean property.
* If the "wakeup-source" property is set, don't request an IRQ.
* This will guarantee the 'wakealarm' sysfs entry is available on the device,
* if supported by the RTC.
*/
if (of_property_read_bool(client->dev.of_node, "wakeup-source")) {
ds1307_can_wakeup_device = true;
}
#endif

switch (ds1307->type) {
case ds_1337:
case ds_1339:
Expand All @@ -957,13 +940,12 @@ static int ds1307_probe(struct i2c_client *client,
ds1307->regs[0] &= ~DS1337_BIT_nEOSC;

/*
* Using IRQ? Disable the square wave and both alarms.
* Using IRQ or defined as wakeup-source?
* Disable the square wave and both alarms.
* For some variants, be sure alarms can trigger when we're
* running on Vbackup (BBSQI/BBSQW)
*/
if (ds1307->client->irq > 0 && chip->alarm) {
INIT_WORK(&ds1307->work, ds1307_work);

if (chip->alarm && (ds1307->client->irq > 0 || ds1307_can_wakeup_device)) {
ds1307->regs[0] |= DS1337_BIT_INTCN
| bbsqi_bitpos[ds1307->type];
ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
Expand Down Expand Up @@ -1053,7 +1035,7 @@ static int ds1307_probe(struct i2c_client *client,
case mcp794xx:
rtc_ops = &mcp794xx_rtc_ops;
if (ds1307->client->irq > 0 && chip->alarm) {
INIT_WORK(&ds1307->work, mcp794xx_work);
irq_handler = mcp794xx_irq;
want_irq = true;
}
break;
Expand Down Expand Up @@ -1168,24 +1150,36 @@ static int ds1307_probe(struct i2c_client *client,
bin2bcd(tmp));
}

device_set_wakeup_capable(&client->dev, want_irq);
if (want_irq) {
device_set_wakeup_capable(&client->dev, true);
set_bit(HAS_ALARM, &ds1307->flags);
}
ds1307->rtc = devm_rtc_device_register(&client->dev, client->name,
rtc_ops, THIS_MODULE);
if (IS_ERR(ds1307->rtc)) {
return PTR_ERR(ds1307->rtc);
}

if (ds1307_can_wakeup_device) {
/* Disable request for an IRQ */
want_irq = false;
dev_info(&client->dev, "'wakeup-source' is set, request for an IRQ is disabled!\n");
/* We cannot support UIE mode if we do not have an IRQ line */
ds1307->rtc->uie_unsupported = 1;
}

if (want_irq) {
err = request_irq(client->irq, ds1307_irq, IRQF_SHARED,
ds1307->rtc->name, client);
err = devm_request_threaded_irq(&client->dev,
client->irq, NULL, irq_handler,
IRQF_SHARED | IRQF_ONESHOT,
ds1307->rtc->name, client);
if (err) {
client->irq = 0;
device_set_wakeup_capable(&client->dev, false);
clear_bit(HAS_ALARM, &ds1307->flags);
dev_err(&client->dev, "unable to request IRQ!\n");
} else {

set_bit(HAS_ALARM, &ds1307->flags);
} else
dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
}
}

if (chip->nvram_size) {
Expand Down Expand Up @@ -1231,11 +1225,6 @@ static int ds1307_remove(struct i2c_client *client)
{
struct ds1307 *ds1307 = i2c_get_clientdata(client);

if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
free_irq(client->irq, client);
cancel_work_sync(&ds1307->work);
}

if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
sysfs_remove_bin_file(&client->dev.kobj, ds1307->nvram);

Expand Down