diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig
index 8d82b1e60514fc6df308dcb4aba2a2c5255ef822..af3a20dd5aa4a504524c0bd36f932ed328903c2c 100644
--- a/drivers/fsi/Kconfig
+++ b/drivers/fsi/Kconfig
@@ -12,6 +12,21 @@ menuconfig FSI
if FSI
+config FSI_NEW_DEV_NODE
+ bool "Create '/dev/fsi' directory for char devices"
+ default n
+ ---help---
+ This option causes char devices created for FSI devices to be
+ located under a common /dev/fsi/ directory. Set to N unless your
+ userspace has been updated to handle the new location.
+
+ Additionally, it also causes the char device names to be offset
+ by one so that chip 0 will have /dev/scom1 and chip1 /dev/scom2
+ to match old userspace expectations.
+
+ New userspace will use udev rules to generate predictable access
+ symlinks in /dev/fsi/by-path when this option is enabled.
+
config FSI_MASTER_GPIO
tristate "GPIO-based FSI master"
depends on GPIOLIB
diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index eab6c5c4990edff9392e4a1ad752116a03afae6c..faa1760a5a4087df33312942f738bf8c7b9db31a 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -92,6 +92,13 @@ struct fsi_slave {
static const int slave_retries = 2;
static int discard_errors;
+static dev_t fsi_base_dev;
+static DEFINE_IDA(fsi_minor_ida);
+#define FSI_CHAR_MAX_DEVICES 0x1000
+
+/* Legacy /dev numbering: 4 devices per chip, 16 chips */
+#define FSI_CHAR_LEGACY_TOP 64
+
static int fsi_master_read(struct fsi_master *master, int link,
uint8_t slave_id, uint32_t addr, void *val, size_t size);
static int fsi_master_write(struct fsi_master *master, int link,
@@ -627,6 +634,7 @@ static void fsi_slave_release(struct device *dev)
{
struct fsi_slave *slave = to_fsi_slave(dev);
+ fsi_free_minor(slave->dev.devt);
of_node_put(dev->of_node);
kfree(slave);
}
@@ -729,6 +737,75 @@ static ssize_t chip_id_show(struct device *dev,
static DEVICE_ATTR_RO(chip_id);
+static char *fsi_cdev_devnode(struct device *dev, umode_t *mode,
+ kuid_t *uid, kgid_t *gid)
+{
+#ifdef CONFIG_FSI_NEW_DEV_NODE
+ return kasprintf(GFP_KERNEL, "fsi/%s", dev_name(dev));
+#else
+ return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
+#endif
+}
+
+const struct device_type fsi_cdev_type = {
+ .name = "fsi-cdev",
+ .devnode = fsi_cdev_devnode,
+};
+EXPORT_SYMBOL_GPL(fsi_cdev_type);
+
+/* Backward compatible /dev/ numbering in "old style" mode */
+static int fsi_adjust_index(int index)
+{
+#ifdef CONFIG_FSI_NEW_DEV_NODE
+ return index;
+#else
+ return index + 1;
+#endif
+}
+
+static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type,
+ dev_t *out_dev, int *out_index)
+{
+ int cid = slave->chip_id;
+ int id;
+
+ /* Check if we qualify for legacy numbering */
+ if (cid >= 0 && cid < 16 && type < 4) {
+ /* Try reserving the legacy number */
+ id = (cid << 4) | type;
+ id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL);
+ if (id >= 0) {
+ *out_index = fsi_adjust_index(cid);
+ *out_dev = fsi_base_dev + id;
+ return 0;
+ }
+ /* Other failure */
+ if (id != -ENOSPC)
+ return id;
+ /* Fallback to non-legacy allocation */
+ }
+ id = ida_simple_get(&fsi_minor_ida, FSI_CHAR_LEGACY_TOP,
+ FSI_CHAR_MAX_DEVICES, GFP_KERNEL);
+ if (id < 0)
+ return id;
+ *out_index = fsi_adjust_index(id);
+ *out_dev = fsi_base_dev + id;
+ return 0;
+}
+
+int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,
+ dev_t *out_dev, int *out_index)
+{
+ return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index);
+}
+EXPORT_SYMBOL_GPL(fsi_get_new_minor);
+
+void fsi_free_minor(dev_t dev)
+{
+ ida_simple_remove(&fsi_minor_ida, MINOR(dev));
+}
+EXPORT_SYMBOL_GPL(fsi_free_minor);
+
static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
{
uint32_t chip_id;
@@ -953,7 +1030,7 @@ static int fsi_slave_remove_device(struct device *dev, void *arg)
static int fsi_master_remove_slave(struct device *dev, void *arg)
{
device_for_each_child(dev, NULL, fsi_slave_remove_device);
- device_unregister(dev);
+ put_device(dev);
return 0;
}
@@ -1091,13 +1168,27 @@ EXPORT_SYMBOL_GPL(fsi_bus_type);
static int __init fsi_init(void)
{
- return bus_register(&fsi_bus_type);
+ int rc;
+
+ rc = alloc_chrdev_region(&fsi_base_dev, 0, FSI_CHAR_MAX_DEVICES, "fsi");
+ if (rc)
+ return rc;
+ rc = bus_register(&fsi_bus_type);
+ if (rc)
+ goto fail_bus;
+ return 0;
+
+ fail_bus:
+ unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);
+ return rc;
}
postcore_initcall(fsi_init);
static void fsi_exit(void)
{
bus_unregister(&fsi_bus_type);
+ unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);
+ ida_destroy(&fsi_minor_ida);
}
module_exit(fsi_exit);
module_param(discard_errors, int, 0664);
diff --git a/include/linux/fsi.h b/include/linux/fsi.h
index 141fd38d061ffbe168355e4938ed83bcf407eca1..ec3be0d5b786ef6f79035efde7cb4d23677df469 100644
--- a/include/linux/fsi.h
+++ b/include/linux/fsi.h
@@ -76,8 +76,18 @@ extern int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
extern int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
const void *val, size_t size);
+extern struct bus_type fsi_bus_type;
+extern const struct device_type fsi_cdev_type;
+enum fsi_dev_type {
+ fsi_dev_cfam,
+ fsi_dev_sbefifo,
+ fsi_dev_scom,
+ fsi_dev_occ
+};
-extern struct bus_type fsi_bus_type;
+extern int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,
+ dev_t *out_dev, int *out_index);
+extern void fsi_free_minor(dev_t dev);
#endif /* LINUX_FSI_H */