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authorPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>2020-09-24 14:44:30 -0500
committerVinod Koul <vkoul@kernel.org>2020-09-28 11:17:43 +0530
commit0173f525b2c1b02a51784e2119d434593235aed1 (patch)
treebe7fd015e55158bb0ce939863460626788948415 /drivers/soundwire
parentfcb9d730be1d3010e0c8fdc5aaff62836d7a942c (diff)
downloadlinux-0173f525b2c1b02a51784e2119d434593235aed1.tar.bz2
soundwire: sysfs: add slave status and device number before probe
The MIPI DisCo device properties that are read by the driver from platform firmware, or hard-coded in the driver, should only be provided as sysfs entries when a driver probes successfully. However the device status and device number is updated even when there is no driver present, and hence can be updated when a Slave device is detected on the bus without being described in platform firmware and without any driver registered/probed. As suggested by GregKH, the attribute group for Slave status and device number is is added by default upon device registration. Credits to Vinod Koul for the status_show() function, shared in a separate patch and used as is here. The status table was modified to remove an unnecessary enum and status_show() is handled in a different group attribute than what was suggested by Vinod. Tested-by: Srinivas Kandgatla <srinivas.kandagatla@linaro.org> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Co-developed-by: Vinod Koul <vkoul@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20200924194430.121058-3-pierre-louis.bossart@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/soundwire')
-rw-r--r--drivers/soundwire/slave.c2
-rw-r--r--drivers/soundwire/sysfs_local.h4
-rw-r--r--drivers/soundwire/sysfs_slave.c58
3 files changed, 63 insertions, 1 deletions
diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
index 19b012310c29..a08f4081c1c4 100644
--- a/drivers/soundwire/slave.c
+++ b/drivers/soundwire/slave.c
@@ -6,6 +6,7 @@
#include <linux/soundwire/sdw.h>
#include <linux/soundwire/sdw_type.h>
#include "bus.h"
+#include "sysfs_local.h"
static void sdw_slave_release(struct device *dev)
{
@@ -51,6 +52,7 @@ int sdw_slave_add(struct sdw_bus *bus,
slave->dev.bus = &sdw_bus_type;
slave->dev.of_node = of_node_get(to_of_node(fwnode));
slave->dev.type = &sdw_slave_type;
+ slave->dev.groups = sdw_slave_status_attr_groups;
slave->bus = bus;
slave->status = SDW_SLAVE_UNATTACHED;
init_completion(&slave->enumeration_complete);
diff --git a/drivers/soundwire/sysfs_local.h b/drivers/soundwire/sysfs_local.h
index ff60adee3c41..7268bc24c538 100644
--- a/drivers/soundwire/sysfs_local.h
+++ b/drivers/soundwire/sysfs_local.h
@@ -8,6 +8,10 @@
* SDW sysfs APIs -
*/
+/* basic attributes to report status of Slave (attachment, dev_num) */
+extern const struct attribute_group *sdw_slave_status_attr_groups[];
+
+/* additional device-managed properties reported after driver probe */
int sdw_slave_sysfs_init(struct sdw_slave *slave);
int sdw_slave_sysfs_dpn_init(struct sdw_slave *slave);
diff --git a/drivers/soundwire/sysfs_slave.c b/drivers/soundwire/sysfs_slave.c
index f510071b0add..b48b6617a396 100644
--- a/drivers/soundwire/sysfs_slave.c
+++ b/drivers/soundwire/sysfs_slave.c
@@ -16,9 +16,13 @@
/*
* The sysfs for Slave reflects the MIPI description as given
- * in the MIPI DisCo spec
+ * in the MIPI DisCo spec.
+ * status and device_number come directly from the MIPI SoundWire
+ * 1.x specification.
*
* Base file is device
+ * |---- status
+ * |---- device_number
* |---- modalias
* |---- dev-properties
* |---- mipi_revision
@@ -212,3 +216,55 @@ int sdw_slave_sysfs_init(struct sdw_slave *slave)
return 0;
}
+
+/*
+ * the status is shown in capital letters for UNATTACHED and RESERVED
+ * on purpose, to highligh users to the fact that these status values
+ * are not expected.
+ */
+static const char *const slave_status[] = {
+ [SDW_SLAVE_UNATTACHED] = "UNATTACHED",
+ [SDW_SLAVE_ATTACHED] = "Attached",
+ [SDW_SLAVE_ALERT] = "Alert",
+ [SDW_SLAVE_RESERVED] = "RESERVED",
+};
+
+static ssize_t status_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct sdw_slave *slave = dev_to_sdw_dev(dev);
+
+ return sprintf(buf, "%s\n", slave_status[slave->status]);
+}
+static DEVICE_ATTR_RO(status);
+
+static ssize_t device_number_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct sdw_slave *slave = dev_to_sdw_dev(dev);
+
+ if (slave->status == SDW_SLAVE_UNATTACHED)
+ return sprintf(buf, "%s", "N/A");
+ else
+ return sprintf(buf, "%d", slave->dev_num);
+}
+static DEVICE_ATTR_RO(device_number);
+
+static struct attribute *slave_status_attrs[] = {
+ &dev_attr_status.attr,
+ &dev_attr_device_number.attr,
+ NULL,
+};
+
+/*
+ * we don't use ATTRIBUTES_GROUP here since the group is used in a
+ * separate file and can't be handled as a static.
+ */
+static const struct attribute_group sdw_slave_status_attr_group = {
+ .attrs = slave_status_attrs,
+};
+
+const struct attribute_group *sdw_slave_status_attr_groups[] = {
+ &sdw_slave_status_attr_group,
+ NULL
+};