diff options
Diffstat (limited to 'drivers/fsi')
| -rw-r--r-- | drivers/fsi/Kconfig | 15 | ||||
| -rw-r--r-- | drivers/fsi/fsi-core.c | 95 |
2 files changed, 108 insertions, 2 deletions
diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig index 8d82b1e60514..af3a20dd5aa4 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 eab6c5c4990e..faa1760a5a40 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); |