ANDROID: w1: ds2482: Manage SLPZ pin sleep state
Place SLPZ pin in sleep state at system suspend time if a GPIO is
provided by board platform data.
Change-Id: I93c61fa0ae474e968e0f909209c9bfcaafe3dd2c
Signed-off-by: Todd Poynor <toddpoynor@google.com>
diff --git a/drivers/w1/masters/ds2482.c b/drivers/w1/masters/ds2482.c
index 2e30db1..fa13fa8 100644
--- a/drivers/w1/masters/ds2482.c
+++ b/drivers/w1/masters/ds2482.c
@@ -18,6 +18,8 @@
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/platform_data/ds2482.h>
#include <asm/delay.h>
#include "../w1.h"
@@ -97,7 +99,8 @@
static int ds2482_probe(struct i2c_client *client,
const struct i2c_device_id *id);
static int ds2482_remove(struct i2c_client *client);
-
+static int ds2482_suspend(struct device *dev);
+static int ds2482_resume(struct device *dev);
/**
* Driver data (common to all clients)
@@ -108,9 +111,15 @@
};
MODULE_DEVICE_TABLE(i2c, ds2482_id);
+static const struct dev_pm_ops ds2482_pm_ops = {
+ .suspend = ds2482_suspend,
+ .resume = ds2482_resume,
+};
+
static struct i2c_driver ds2482_driver = {
.driver = {
.name = "ds2482",
+ .pm = &ds2482_pm_ops,
},
.probe = ds2482_probe,
.remove = ds2482_remove,
@@ -132,6 +141,7 @@
struct ds2482_data {
struct i2c_client *client;
struct mutex access_lock;
+ int slpz_gpio;
/* 1-wire interface(s) */
int w1_count; /* 1 or 8 */
@@ -460,11 +470,31 @@
return retval;
}
+static int ds2482_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ds2482_data *data = i2c_get_clientdata(client);
+
+ if (data->slpz_gpio >= 0)
+ gpio_set_value(data->slpz_gpio, 0);
+ return 0;
+}
+
+static int ds2482_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ds2482_data *data = i2c_get_clientdata(client);
+
+ if (data->slpz_gpio >= 0)
+ gpio_set_value(data->slpz_gpio, 1);
+ return 0;
+}
static int ds2482_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ds2482_data *data;
+ struct ds2482_platform_data *pdata;
int err = -ENODEV;
int temp1;
int idx;
@@ -531,6 +561,16 @@
}
}
+ pdata = client->dev.platform_data;
+ data->slpz_gpio = pdata ? pdata->slpz_gpio : -1;
+
+ if (data->slpz_gpio >= 0) {
+ err = gpio_request_one(data->slpz_gpio, GPIOF_OUT_INIT_HIGH,
+ "ds2482.slpz");
+ if (err < 0)
+ goto exit_w1_remove;
+ }
+
return 0;
exit_w1_remove:
@@ -555,6 +595,11 @@
w1_remove_master_device(&data->w1_ch[idx].w1_bm);
}
+ if (data->slpz_gpio >= 0) {
+ gpio_set_value(data->slpz_gpio, 0);
+ gpio_free(data->slpz_gpio);
+ }
+
/* Free the memory */
kfree(data);
return 0;
diff --git a/include/linux/platform_data/ds2482.h b/include/linux/platform_data/ds2482.h
new file mode 100644
index 0000000..5a6879e2a
--- /dev/null
+++ b/include/linux/platform_data/ds2482.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2012 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#ifndef __PLATFORM_DATA_DS2482__
+#define __PLATFORM_DATA_DS2482__
+
+struct ds2482_platform_data {
+ int slpz_gpio;
+};
+
+#endif /* __PLATFORM_DATA_DS2482__ */