2023-11-04 06:48:14

by huaweicloud

[permalink] [raw]
Subject: [PATCH v3 -next 3/5] spi: mockup: Add support register the device through configfs

From: Zhang Xiaoxu <[email protected]>

This enable/disable the spi mockup device through the configfs:

mkdir /sys/kernel/config/spi-mockup/spi0

echo 1 > /sys/kernel/config/spi-mockup/spi0/enable
echo 1 > /sys/kernel/config/spi-mockup/spi0/disable

Signed-off-by: Zhang Xiaoxu <[email protected]>
---
drivers/spi/spi-mockup.c | 163 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 161 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-mockup.c b/drivers/spi/spi-mockup.c
index fcaaa61bdb38..b449a2b7cdd4 100644
--- a/drivers/spi/spi-mockup.c
+++ b/drivers/spi/spi-mockup.c
@@ -12,6 +12,7 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
+#include <linux/configfs.h>

#define CREATE_TRACE_POINTS
#include <trace/events/spi_mockup.h>
@@ -224,7 +225,7 @@ static int spi_mockup_probe(struct platform_device *pdev)
ctrl->dev.groups = spi_mockup_groups;
ctrl->num_chipselect = MOCKUP_CHIPSELECT_MAX;
ctrl->mode_bits = SPI_MODE_USER_MASK;
- ctrl->bus_num = 0;
+ ctrl->bus_num = pdev->id;
ctrl->transfer_one_message = spi_mockup_transfer;

mock = spi_controller_get_devdata(ctrl);
@@ -252,7 +253,165 @@ static struct platform_driver spi_mockup_driver = {
.of_match_table = spi_mockup_match,
},
};
-module_platform_driver(spi_mockup_driver);
+
+struct spi_mockup_device {
+ struct config_group group;
+ unsigned int bus_nr;
+ struct mutex lock;
+ struct platform_device *pdev;
+};
+
+static struct spi_mockup_device *to_spi_mockup_dev(struct config_item *item)
+{
+ struct config_group *group = to_config_group(item);
+
+ return container_of(group, struct spi_mockup_device, group);
+}
+
+static ssize_t
+spi_mockup_enable_store(struct config_item *item, const char *page, size_t len)
+{
+ int ret = len;
+ struct platform_device_info pdevinfo = {0};
+ struct spi_mockup_device *dev = to_spi_mockup_dev(item);
+
+ mutex_lock(&dev->lock);
+ if (dev->pdev) {
+ ret = -EEXIST;
+ goto out;
+ }
+
+ pdevinfo.name = "spi-mockup";
+ pdevinfo.id = dev->bus_nr;
+ dev->pdev = platform_device_register_full(&pdevinfo);
+ if (IS_ERR(dev->pdev)) {
+ ret = PTR_ERR(dev->pdev);
+ dev->pdev = NULL;
+ goto out;
+ }
+out:
+ mutex_unlock(&dev->lock);
+ return ret;
+}
+CONFIGFS_ATTR_WO(spi_mockup_, enable);
+
+static ssize_t
+spi_mockup_disable_store(struct config_item *item, const char *page, size_t len)
+{
+ int ret = len;
+ struct spi_mockup_device *dev = to_spi_mockup_dev(item);
+
+ mutex_lock(&dev->lock);
+ if (!dev->pdev) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ platform_device_unregister(dev->pdev);
+ dev->pdev = NULL;
+out:
+ mutex_unlock(&dev->lock);
+ return ret;
+}
+CONFIGFS_ATTR_WO(spi_mockup_, disable);
+
+static struct configfs_attribute *spi_mockup_configfs_attrs[] = {
+ &spi_mockup_attr_enable,
+ &spi_mockup_attr_disable,
+ NULL,
+};
+
+static const struct config_item_type spi_mockup_device_config_group_type = {
+ .ct_owner = THIS_MODULE,
+ .ct_attrs = spi_mockup_configfs_attrs,
+};
+
+static struct config_group *
+spi_mockup_config_make_device_group(struct config_group *group,
+ const char *name)
+{
+ int ret, nchar;
+ unsigned int nr;
+ struct spi_mockup_device *dev;
+
+ ret = sscanf(name, "spi%u%n", &nr, &nchar);
+ if (ret != 1 || nchar != strlen(name))
+ return ERR_PTR(-EINVAL);
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return ERR_PTR(-ENOMEM);
+
+ dev->bus_nr = nr;
+ mutex_init(&dev->lock);
+
+ config_group_init_type_name(&dev->group, name,
+ &spi_mockup_device_config_group_type);
+
+ return &dev->group;
+}
+
+static void spi_mockup_config_group_release(struct config_item *item)
+{
+ struct spi_mockup_device *dev = to_spi_mockup_dev(item);
+
+ kfree(dev);
+}
+
+static struct configfs_item_operations spi_mockup_config_item_ops = {
+ .release = spi_mockup_config_group_release,
+};
+
+static struct configfs_group_operations spi_mockup_config_group_ops = {
+ .make_group = spi_mockup_config_make_device_group,
+};
+
+static const struct config_item_type spi_mockup_config_type = {
+ .ct_owner = THIS_MODULE,
+ .ct_group_ops = &spi_mockup_config_group_ops,
+ .ct_item_ops = &spi_mockup_config_item_ops,
+};
+
+static struct configfs_subsystem spi_mockup_config_subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "spi-mockup",
+ .ci_type = &spi_mockup_config_type,
+ }
+ }
+};
+
+static int __init spi_mockup_init(void)
+{
+ int ret;
+
+ ret = platform_driver_register(&spi_mockup_driver);
+ if (ret) {
+ pr_err("spi mockup driver registering failed with %d\n", ret);
+ return ret;
+ }
+
+ config_group_init(&spi_mockup_config_subsys.su_group);
+ mutex_init(&spi_mockup_config_subsys.su_mutex);
+ ret = configfs_register_subsystem(&spi_mockup_config_subsys);
+ if (ret) {
+ pr_err("spi mockup configfs registering failed with %d\n", ret);
+ mutex_destroy(&spi_mockup_config_subsys.su_mutex);
+ platform_driver_unregister(&spi_mockup_driver);
+ return ret;
+ }
+
+ return ret;
+}
+module_init(spi_mockup_init);
+
+static void __exit spi_mockup_exit(void)
+{
+ configfs_unregister_subsystem(&spi_mockup_config_subsys);
+ mutex_destroy(&spi_mockup_config_subsys.su_mutex);
+ return platform_driver_unregister(&spi_mockup_driver);
+}
+module_exit(spi_mockup_exit);

MODULE_AUTHOR("Wei Yongjun <[email protected]>");
MODULE_DESCRIPTION("SPI controller Testing Driver");
--
2.34.1