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authorJohan Hovold <johan@kernel.org>2018-06-01 10:22:59 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-06-28 20:32:51 +0900
commit10f146639fee5ffaf7cf0081c1af518f7d0c533c (patch)
tree1fdc31ab3bf22339c89db3b7ba134c6aad9579cf
parentd2efbbd18b1e26ac79401841089e4a4b97d745c3 (diff)
gnss: add receiver type support
Add a "type" device attribute and a "GNSS_TYPE" uevent variable which can be used to determine the type of a GNSS receiver. The currently identified types reflect the protocol(s) supported by a receiver: "NMEA" NMEA 0183 "SiRF" SiRF Binary "UBX" UBX Note that both SiRF and UBX type receivers typically support a subset of NMEA 0183 with vendor extensions (e.g. to allow switching to the vendor protocol). Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--Documentation/ABI/testing/sysfs-class-gnss15
-rw-r--r--MAINTAINERS1
-rw-r--r--drivers/gnss/core.c49
-rw-r--r--drivers/gnss/sirf.c1
-rw-r--r--drivers/gnss/ubx.c2
-rw-r--r--include/linux/gnss.h9
6 files changed, 77 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-gnss b/Documentation/ABI/testing/sysfs-class-gnss
new file mode 100644
index 000000000000..2467b6900eae
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-gnss
@@ -0,0 +1,15 @@
+What: /sys/class/gnss/gnssN/type
+Date: May 2018
+KernelVersion: 4.18
+Contact: Johan Hovold <johan@kernel.org>
+Description:
+ The GNSS receiver type. The currently identified types reflect
+ the protocol(s) supported by the receiver:
+
+ "NMEA" NMEA 0183
+ "SiRF" SiRF Binary
+ "UBX" UBX
+
+ Note that also non-"NMEA" type receivers typically support a
+ subset of NMEA 0183 with vendor extensions (e.g. to allow
+ switching to a vendor protocol).
diff --git a/MAINTAINERS b/MAINTAINERS
index f980c6186094..e01d220a6f05 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6041,6 +6041,7 @@ F: include/uapi/linux/gigaset_dev.h
GNSS SUBSYSTEM
M: Johan Hovold <johan@kernel.org>
S: Maintained
+F: Documentation/ABI/testing/sysfs-class-gnss
F: Documentation/devicetree/bindings/gnss/
F: drivers/gnss/
F: include/linux/gnss.h
diff --git a/drivers/gnss/core.c b/drivers/gnss/core.c
index 307894ca2725..f30ef8338b3a 100644
--- a/drivers/gnss/core.c
+++ b/drivers/gnss/core.c
@@ -330,6 +330,52 @@ int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
}
EXPORT_SYMBOL_GPL(gnss_insert_raw);
+static const char * const gnss_type_names[GNSS_TYPE_COUNT] = {
+ [GNSS_TYPE_NMEA] = "NMEA",
+ [GNSS_TYPE_SIRF] = "SiRF",
+ [GNSS_TYPE_UBX] = "UBX",
+};
+
+static const char *gnss_type_name(struct gnss_device *gdev)
+{
+ const char *name = NULL;
+
+ if (gdev->type < GNSS_TYPE_COUNT)
+ name = gnss_type_names[gdev->type];
+
+ if (!name)
+ dev_WARN(&gdev->dev, "type name not defined\n");
+
+ return name;
+}
+
+static ssize_t type_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct gnss_device *gdev = to_gnss_device(dev);
+
+ return sprintf(buf, "%s\n", gnss_type_name(gdev));
+}
+static DEVICE_ATTR_RO(type);
+
+static struct attribute *gnss_attrs[] = {
+ &dev_attr_type.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(gnss);
+
+static int gnss_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ struct gnss_device *gdev = to_gnss_device(dev);
+ int ret;
+
+ ret = add_uevent_var(env, "GNSS_TYPE=%s", gnss_type_name(gdev));
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
static int __init gnss_module_init(void)
{
int ret;
@@ -347,6 +393,9 @@ static int __init gnss_module_init(void)
goto err_unregister_chrdev;
}
+ gnss_class->dev_groups = gnss_groups;
+ gnss_class->dev_uevent = gnss_uevent;
+
pr_info("GNSS driver registered with major %d\n", MAJOR(gnss_first));
return 0;
diff --git a/drivers/gnss/sirf.c b/drivers/gnss/sirf.c
index 5fb0f730db48..79cb98950013 100644
--- a/drivers/gnss/sirf.c
+++ b/drivers/gnss/sirf.c
@@ -267,6 +267,7 @@ static int sirf_probe(struct serdev_device *serdev)
if (!gdev)
return -ENOMEM;
+ gdev->type = GNSS_TYPE_SIRF;
gdev->ops = &sirf_gnss_ops;
gnss_set_drvdata(gdev, data);
diff --git a/drivers/gnss/ubx.c b/drivers/gnss/ubx.c
index ecddfb362a6f..902b6854b7db 100644
--- a/drivers/gnss/ubx.c
+++ b/drivers/gnss/ubx.c
@@ -77,6 +77,8 @@ static int ubx_probe(struct serdev_device *serdev)
gserial->ops = &ubx_gserial_ops;
+ gserial->gdev->type = GNSS_TYPE_UBX;
+
data = gnss_serial_get_drvdata(gserial);
data->vcc = devm_regulator_get(&serdev->dev, "vcc");
diff --git a/include/linux/gnss.h b/include/linux/gnss.h
index e26aeac1e0e2..43546977098c 100644
--- a/include/linux/gnss.h
+++ b/include/linux/gnss.h
@@ -18,6 +18,14 @@
struct gnss_device;
+enum gnss_type {
+ GNSS_TYPE_NMEA = 0,
+ GNSS_TYPE_SIRF,
+ GNSS_TYPE_UBX,
+
+ GNSS_TYPE_COUNT
+};
+
struct gnss_operations {
int (*open)(struct gnss_device *gdev);
void (*close)(struct gnss_device *gdev);
@@ -30,6 +38,7 @@ struct gnss_device {
struct cdev cdev;
int id;
+ enum gnss_type type;
unsigned long flags;
struct rw_semaphore rwsem;