[PATCH 07/19] bus/cdx: add device attributes
From: Nipun Gupta
Date: Tue Jan 17 2023 - 08:43:58 EST
Create sysfs entry for CDX devices.
Sysfs entries provided in each of the CDX device detected by
the CDX controller
- vendor id
- device id
- remove
- reset of the device.
- driver override
Signed-off-by: Puneet Gupta <puneet.gupta@xxxxxxx>
Signed-off-by: Nipun Gupta <nipun.gupta@xxxxxxx>
Signed-off-by: Tarak Reddy <tarak.reddy@xxxxxxx>
---
Documentation/ABI/testing/sysfs-bus-cdx | 34 +++++
drivers/bus/cdx/cdx.c | 144 ++++++++++++++++++++
drivers/bus/cdx/controller/cdx_controller.c | 19 +++
drivers/bus/cdx/controller/mcdi_functions.c | 14 ++
drivers/bus/cdx/controller/mcdi_functions.h | 11 ++
include/linux/cdx/cdx_bus.h | 23 ++++
6 files changed, 245 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-cdx b/Documentation/ABI/testing/sysfs-bus-cdx
index 8c2425fdb6d9..1e0fdce18cde 100644
--- a/Documentation/ABI/testing/sysfs-bus-cdx
+++ b/Documentation/ABI/testing/sysfs-bus-cdx
@@ -10,3 +10,37 @@ Description:
For example::
# echo 1 > /sys/bus/cdx/rescan
+
+What: /sys/bus/cdx/devices/.../vendor
+Date: January 2023
+Contact: nipun.gupta@xxxxxxx
+Description:
+ Vendor ID for this CDX device
+
+What: /sys/bus/cdx/devices/.../device
+Date: January 2023
+Contact: nipun.gupta@xxxxxxx
+Description:
+ Device ID for this CDX device
+
+What: /sys/bus/cdx/devices/.../reset
+Date: January 2023
+Contact: nipun.gupta@xxxxxxx
+Description:
+ Writing a non-zero value to this file would reset the
+ CDX device
+
+ For example::
+
+ # echo 1 > /sys/bus/cdx/.../reset
+
+What: /sys/bus/cdx/devices/.../remove
+Date: January 2023
+Contact: tarak.reddy@xxxxxxx
+Description:
+ Writing a non-zero value to this file would remove the
+ corrosponding device from the CDX bus
+
+ For example::
+
+ # echo 1 > /sys/bus/cdx/devices/.../remove
diff --git a/drivers/bus/cdx/cdx.c b/drivers/bus/cdx/cdx.c
index 2737470f08d3..1372d8dcaa4c 100644
--- a/drivers/bus/cdx/cdx.c
+++ b/drivers/bus/cdx/cdx.c
@@ -72,6 +72,38 @@ static DECLARE_BITMAP(cdx_controller_id_map, MAX_CDX_CONTROLLERS);
/* List of CDX controllers registered with the CDX bus */
static LIST_HEAD(cdx_controllers);
+/**
+ * reset_cdx_device - Reset a CDX device
+ * @dev: CDX device
+ * @data: This is always passed as NULL, and is not used in this API,
+ * but is required here as the bus_for_each_dev() API expects
+ * the passed function (reset_cdx_device) to have this
+ * as an argument.
+ *
+ * @return: -errno on failure, 0 on success.
+ */
+static int reset_cdx_device(struct device *dev, void *data)
+{
+ struct cdx_device *cdx_dev = to_cdx_device(dev);
+ struct cdx_controller *cdx = cdx_dev->cdx;
+ struct cdx_device_config dev_config;
+ int ret;
+
+ dev_config.type = CDX_DEV_RESET_CONF;
+ ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
+ cdx_dev->dev_num, &dev_config);
+ if (ret)
+ dev_err(dev, "cdx device reset failed\n");
+
+ return ret;
+}
+
+int cdx_dev_reset(struct device *dev)
+{
+ return reset_cdx_device(dev, NULL);
+}
+EXPORT_SYMBOL_GPL(cdx_dev_reset);
+
/**
* cdx_unregister_device - Unregister a CDX device
* @dev: CDX device
@@ -238,6 +270,117 @@ static int cdx_dma_configure(struct device *dev)
return 0;
}
+/* show configuration fields */
+#define cdx_config_attr(field, format_string) \
+static ssize_t \
+field##_show(struct device *dev, struct device_attribute *attr, char *buf) \
+{ \
+ struct cdx_device *cdx_dev = to_cdx_device(dev); \
+ return sysfs_emit(buf, format_string, cdx_dev->field); \
+} \
+static DEVICE_ATTR_RO(field)
+
+cdx_config_attr(vendor, "0x%04x\n");
+cdx_config_attr(device, "0x%04x\n");
+
+static ssize_t remove_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned long val = 0;
+
+ if (kstrtoul(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ if (!val)
+ return -EINVAL;
+
+ if (device_remove_file_self(dev, attr)) {
+ int ret;
+
+ ret = cdx_unregister_device(dev, NULL);
+ if (ret)
+ return ret;
+ }
+
+ return count;
+}
+static DEVICE_ATTR_WO(remove);
+
+static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned long val = 0;
+ int ret = 0;
+
+ if (kstrtoul(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ if (!val)
+ return -EINVAL;
+
+ ret = reset_cdx_device(dev, NULL);
+ if (ret)
+ return ret;
+
+ return count;
+}
+static DEVICE_ATTR_WO(reset);
+
+static ssize_t driver_override_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct cdx_device *cdx_dev = to_cdx_device(dev);
+ const char *old = cdx_dev->driver_override;
+ char *driver_override;
+ char *cp;
+
+ if (WARN_ON(dev->bus != &cdx_bus_type))
+ return -EINVAL;
+
+ if (count >= (PAGE_SIZE - 1))
+ return -EINVAL;
+
+ driver_override = kstrndup(buf, count, GFP_KERNEL);
+ if (!driver_override)
+ return -ENOMEM;
+
+ cp = strchr(driver_override, '\n');
+ if (cp)
+ *cp = '\0';
+
+ if (strlen(driver_override)) {
+ cdx_dev->driver_override = driver_override;
+ } else {
+ kfree(driver_override);
+ cdx_dev->driver_override = NULL;
+ }
+
+ kfree(old);
+
+ return count;
+}
+
+static ssize_t driver_override_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct cdx_device *cdx_dev = to_cdx_device(dev);
+
+ return sysfs_emit(buf, "%s\n", cdx_dev->driver_override);
+}
+static DEVICE_ATTR_RW(driver_override);
+
+static struct attribute *cdx_dev_attrs[] = {
+ &dev_attr_remove.attr,
+ &dev_attr_reset.attr,
+ &dev_attr_vendor.attr,
+ &dev_attr_device.attr,
+ &dev_attr_driver_override.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(cdx_dev);
+
static ssize_t rescan_store(struct bus_type *bus,
const char *buf, size_t count)
{
@@ -280,6 +423,7 @@ struct bus_type cdx_bus_type = {
.shutdown = cdx_shutdown,
.dma_configure = cdx_dma_configure,
.bus_groups = cdx_bus_groups,
+ .dev_groups = cdx_dev_groups,
};
EXPORT_SYMBOL_GPL(cdx_bus_type);
diff --git a/drivers/bus/cdx/controller/cdx_controller.c b/drivers/bus/cdx/controller/cdx_controller.c
index b62a6d3b7bd4..dbcd236b360d 100644
--- a/drivers/bus/cdx/controller/cdx_controller.c
+++ b/drivers/bus/cdx/controller/cdx_controller.c
@@ -85,6 +85,24 @@ void cdx_rpmsg_pre_remove(struct cdx_controller *cdx)
cdx_mcdi_wait_for_quiescence(cdx->priv, MCDI_RPC_TIMEOUT);
}
+static int cdx_configure_device(struct cdx_controller *cdx,
+ u8 bus_num, u8 dev_num,
+ struct cdx_device_config *dev_config)
+{
+ int ret = 0;
+
+ switch (dev_config->type) {
+ case CDX_DEV_RESET_CONF:
+ ret = cdx_mcdi_reset_device(cdx->priv, bus_num, dev_num);
+ break;
+ default:
+ dev_err(cdx->dev, "Invalid device configuration flag\n");
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
static int cdx_scan_devices(struct cdx_controller *cdx)
{
struct cdx_mcdi *cdx_mcdi = cdx->priv;
@@ -144,6 +162,7 @@ static int cdx_scan_devices(struct cdx_controller *cdx)
static struct cdx_ops cdx_ops = {
.scan = cdx_scan_devices,
+ .dev_configure = cdx_configure_device,
};
static int xlnx_cdx_probe(struct platform_device *pdev)
diff --git a/drivers/bus/cdx/controller/mcdi_functions.c b/drivers/bus/cdx/controller/mcdi_functions.c
index 3940a2c7919c..673b3896411e 100644
--- a/drivers/bus/cdx/controller/mcdi_functions.c
+++ b/drivers/bus/cdx/controller/mcdi_functions.c
@@ -123,3 +123,17 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx,
return 0;
}
+
+int cdx_mcdi_reset_device(struct cdx_mcdi *cdx, u8 bus_num, u8 dev_num)
+{
+ MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_DEVICE_RESET_IN_LEN);
+ int rc;
+
+ MCDI_SET_DWORD(inbuf, CDX_DEVICE_RESET_IN_BUS, bus_num);
+ MCDI_SET_DWORD(inbuf, CDX_DEVICE_RESET_IN_DEVICE, dev_num);
+
+ rc = cdx_mcdi_rpc(cdx, MC_CMD_CDX_DEVICE_RESET, inbuf, sizeof(inbuf),
+ NULL, 0, NULL);
+
+ return rc;
+}
diff --git a/drivers/bus/cdx/controller/mcdi_functions.h b/drivers/bus/cdx/controller/mcdi_functions.h
index 97dfde18592f..54d6017ab7d1 100644
--- a/drivers/bus/cdx/controller/mcdi_functions.h
+++ b/drivers/bus/cdx/controller/mcdi_functions.h
@@ -47,4 +47,15 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx,
u8 bus_num, u8 dev_num,
struct cdx_dev_params *dev_params);
+/**
+ * cdx_mcdi_reset_device - Reset cdx device represented by bus_num:dev_num
+ * @cdx: pointer to MCDI interface.
+ * @bus_num: Bus number.
+ * @dev_num: Device number.
+ *
+ * @return: 0 on success, <0 on failure
+ */
+int cdx_mcdi_reset_device(struct cdx_mcdi *cdx,
+ u8 bus_num, u8 dev_num);
+
#endif /* CDX_MCDI_FUNCTIONS_H */
diff --git a/include/linux/cdx/cdx_bus.h b/include/linux/cdx/cdx_bus.h
index 1d28f11da5e7..9f055739ed30 100644
--- a/include/linux/cdx/cdx_bus.h
+++ b/include/linux/cdx/cdx_bus.h
@@ -21,8 +21,20 @@
/* Forward declaration for CDX controller */
struct cdx_controller;
+enum {
+ CDX_DEV_RESET_CONF,
+};
+
+struct cdx_device_config {
+ u8 type;
+};
+
typedef int (*cdx_scan_cb)(struct cdx_controller *cdx);
+typedef int (*cdx_dev_configure_cb)(struct cdx_controller *cdx,
+ u8 bus_num, u8 dev_num,
+ struct cdx_device_config *dev_config);
+
/**
* CDX_DEVICE_DRIVER_OVERRIDE - macro used to describe a CDX device with
* override_only flags.
@@ -39,9 +51,12 @@ typedef int (*cdx_scan_cb)(struct cdx_controller *cdx);
/**
* struct cdx_ops - Callbacks supported by CDX controller.
* @scan: scan the devices on the controller
+ * @dev_configure: configuration like reset, master_enable,
+ * msi_config etc for a CDX device
*/
struct cdx_ops {
cdx_scan_cb scan;
+ cdx_dev_configure_cb dev_configure;
};
/**
@@ -150,4 +165,12 @@ void cdx_driver_unregister(struct cdx_driver *cdx_driver);
extern struct bus_type cdx_bus_type;
+/**
+ * cdx_dev_reset - Reset CDX device
+ * @dev: device pointer
+ *
+ * @return: 0 for success, -errno on failure
+ */
+int cdx_dev_reset(struct device *dev);
+
#endif /* _CDX_BUS_H_ */
--
2.17.1