diff options
Diffstat (limited to 'drivers/fsi/fsi-core.c')
| -rw-r--r-- | drivers/fsi/fsi-core.c | 67 |
1 files changed, 49 insertions, 18 deletions
diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c index 1f76740f33b6..8244da8a7241 100644 --- a/drivers/fsi/fsi-core.c +++ b/drivers/fsi/fsi-core.c @@ -544,6 +544,31 @@ static int fsi_slave_scan(struct fsi_slave *slave) return 0; } +static unsigned long aligned_access_size(size_t offset, size_t count) +{ + unsigned long offset_unit, count_unit; + + /* Criteria: + * + * 1. Access size must be less than or equal to the maximum access + * width or the highest power-of-two factor of offset + * 2. Access size must be less than or equal to the amount specified by + * count + * + * The access width is optimal if we can calculate 1 to be strictly + * equal while still satisfying 2. + */ + + /* Find 1 by the bottom bit of offset (with a 4 byte access cap) */ + offset_unit = BIT(__builtin_ctzl(offset | 4)); + + /* Find 2 by the top bit of count */ + count_unit = BIT(8 * sizeof(unsigned long) - 1 - __builtin_clzl(count)); + + /* Constrain the maximum access width to the minimum of both criteria */ + return BIT(__builtin_ctzl(offset_unit | count_unit)); +} + static ssize_t fsi_slave_sysfs_raw_read(struct file *file, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) @@ -559,8 +584,7 @@ static ssize_t fsi_slave_sysfs_raw_read(struct file *file, return -EINVAL; for (total_len = 0; total_len < count; total_len += read_len) { - read_len = min_t(size_t, count, 4); - read_len -= off & 0x3; + read_len = aligned_access_size(off, count - total_len); rc = fsi_slave_read(slave, off, buf + total_len, read_len); if (rc) @@ -587,8 +611,7 @@ static ssize_t fsi_slave_sysfs_raw_write(struct file *file, return -EINVAL; for (total_len = 0; total_len < count; total_len += write_len) { - write_len = min_t(size_t, count, 4); - write_len -= off & 0x3; + write_len = aligned_access_size(off, count - total_len); rc = fsi_slave_write(slave, off, buf + total_len, write_len); if (rc) @@ -1241,6 +1264,19 @@ static ssize_t master_break_store(struct device *dev, static DEVICE_ATTR(break, 0200, NULL, master_break_store); +static struct attribute *master_attrs[] = { + &dev_attr_break.attr, + &dev_attr_rescan.attr, + NULL +}; + +ATTRIBUTE_GROUPS(master); + +static struct class fsi_master_class = { + .name = "fsi-master", + .dev_groups = master_groups, +}; + int fsi_master_register(struct fsi_master *master) { int rc; @@ -1249,6 +1285,7 @@ int fsi_master_register(struct fsi_master *master) mutex_init(&master->scan_lock); master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL); dev_set_name(&master->dev, "fsi%d", master->idx); + master->dev.class = &fsi_master_class; rc = device_register(&master->dev); if (rc) { @@ -1256,20 +1293,6 @@ int fsi_master_register(struct fsi_master *master) return rc; } - rc = device_create_file(&master->dev, &dev_attr_rescan); - if (rc) { - device_del(&master->dev); - ida_simple_remove(&master_ida, master->idx); - return rc; - } - - rc = device_create_file(&master->dev, &dev_attr_break); - if (rc) { - device_del(&master->dev); - ida_simple_remove(&master_ida, master->idx); - return rc; - } - np = dev_of_node(&master->dev); if (!of_property_read_bool(np, "no-scan-on-init")) { mutex_lock(&master->scan_lock); @@ -1350,8 +1373,15 @@ static int __init fsi_init(void) rc = bus_register(&fsi_bus_type); if (rc) goto fail_bus; + + rc = class_register(&fsi_master_class); + if (rc) + goto fail_class; + return 0; + fail_class: + bus_unregister(&fsi_bus_type); fail_bus: unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES); return rc; @@ -1360,6 +1390,7 @@ postcore_initcall(fsi_init); static void fsi_exit(void) { + class_unregister(&fsi_master_class); bus_unregister(&fsi_bus_type); unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES); ida_destroy(&fsi_minor_ida); |