rtc: ds1307: Support optional wakeup interrupt source

With the recent pinctrl-single changes, SoCs such as Texas
Instrument's OMAP processors can treat wake-up events from deeper idle
states as interrupts.

Let's add support for the optional second interrupt for wake-up using
the generic wakeirq support added in commit 4990d4fe327b ("PM /
Wakeirq: Add automated device wake IRQ handling")

Finally, to pass the wake-up interrupt in the dts file,
interrupts-extended property needs to be passed.

This is similar in approach to commit 2a0b965cfb6e ("serial: omap: Add
support for optional wake-up") + ee83bd3b6483 ("serial: omap: Switch
wake-up interrupt to generic wakeirq")

Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

1 files changed, 33 insertions, 3 deletions

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index b03880fc32b5..e16989c48a90 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -15,6 +15,9 @@
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/pm_wakeirq.h>
 #include <linux/rtc/ds1307.h>
 #include <linux/rtc.h>
 #include <linux/slab.h>
@@ -114,6 +117,7 @@ struct ds1307 {
 #define HAS_ALARM       1               /* bit 1 == irq claimed */
         struct i2c_client       *client;
         struct rtc_device       *rtc;
+        int                     wakeirq;
         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,
@@ -1156,6 +1160,8 @@ read_rtc:
         }
 
         if (want_irq) {
+                struct device_node *node = client->dev.of_node;
+
                 err = devm_request_threaded_irq(&client->dev,
                                                 client->irq, NULL, irq_handler,
                                                 IRQF_SHARED | IRQF_ONESHOT,
@@ -1163,13 +1169,34 @@ read_rtc:
                 if (err) {
                         client->irq = 0;
                         dev_err(&client->dev, "unable to request IRQ!\n");
-                } else {
+                        goto no_irq;
+                }
 
-                        set_bit(HAS_ALARM, &ds1307->flags);
-                        dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
+                set_bit(HAS_ALARM, &ds1307->flags);
+                dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
+
+                /* Currently supported by OF code only! */
+                if (!node)
+                        goto no_irq;
+
+                err = of_irq_get(node, 1);
+                if (err <= 0) {
+                        if (err == -EPROBE_DEFER)
+                                goto exit;
+                        goto no_irq;
+                }
+                ds1307->wakeirq = err;
+
+                err = dev_pm_set_dedicated_wake_irq(&client->dev,
+                                                    ds1307->wakeirq);
+                if (err) {
+                        dev_err(&client->dev, "unable to setup wakeIRQ %d!\n",
+                                err);
+                        goto exit;
                 }
         }
 
+no_irq:
         if (chip->nvram_size) {
 
                 ds1307->nvram = devm_kzalloc(&client->dev,
@@ -1213,6 +1240,9 @@ static int ds1307_remove(struct i2c_client *client)
 {
         struct ds1307 *ds1307 = i2c_get_clientdata(client);
 
+        if (ds1307->wakeirq)
+                dev_pm_clear_wake_irq(&client->dev);
+
         if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
                 sysfs_remove_bin_file(&client->dev.kobj, ds1307->nvram);