1 /* 2 * Remote Processor Framework 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * version 2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 */ 13 14 #include <linux/remoteproc.h> 15 16 #include "remoteproc_internal.h" 17 18 #define to_rproc(d) container_of(d, struct rproc, dev) 19 20 /* Expose the loaded / running firmware name via sysfs */ 21 static ssize_t firmware_show(struct device *dev, struct device_attribute *attr, 22 char *buf) 23 { 24 struct rproc *rproc = to_rproc(dev); 25 26 return sprintf(buf, "%s\n", rproc->firmware); 27 } 28 29 /* Change firmware name via sysfs */ 30 static ssize_t firmware_store(struct device *dev, 31 struct device_attribute *attr, 32 const char *buf, size_t count) 33 { 34 struct rproc *rproc = to_rproc(dev); 35 char *p; 36 int err, len = count; 37 38 err = mutex_lock_interruptible(&rproc->lock); 39 if (err) { 40 dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, err); 41 return -EINVAL; 42 } 43 44 if (rproc->state != RPROC_OFFLINE) { 45 dev_err(dev, "can't change firmware while running\n"); 46 err = -EBUSY; 47 goto out; 48 } 49 50 len = strcspn(buf, "\n"); 51 52 p = kstrndup(buf, len, GFP_KERNEL); 53 if (!p) { 54 err = -ENOMEM; 55 goto out; 56 } 57 58 kfree(rproc->firmware); 59 rproc->firmware = p; 60 out: 61 mutex_unlock(&rproc->lock); 62 63 return err ? err : count; 64 } 65 static DEVICE_ATTR_RW(firmware); 66 67 /* 68 * A state-to-string lookup table, for exposing a human readable state 69 * via sysfs. Always keep in sync with enum rproc_state 70 */ 71 static const char * const rproc_state_string[] = { 72 [RPROC_OFFLINE] = "offline", 73 [RPROC_SUSPENDED] = "suspended", 74 [RPROC_RUNNING] = "running", 75 [RPROC_CRASHED] = "crashed", 76 [RPROC_DELETED] = "deleted", 77 [RPROC_LAST] = "invalid", 78 }; 79 80 /* Expose the state of the remote processor via sysfs */ 81 static ssize_t state_show(struct device *dev, struct device_attribute *attr, 82 char *buf) 83 { 84 struct rproc *rproc = to_rproc(dev); 85 unsigned int state; 86 87 state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state; 88 return sprintf(buf, "%s\n", rproc_state_string[state]); 89 } 90 91 /* Change remote processor state via sysfs */ 92 static ssize_t state_store(struct device *dev, 93 struct device_attribute *attr, 94 const char *buf, size_t count) 95 { 96 struct rproc *rproc = to_rproc(dev); 97 int ret = 0; 98 99 if (sysfs_streq(buf, "start")) { 100 if (rproc->state == RPROC_RUNNING) 101 return -EBUSY; 102 103 ret = rproc_boot(rproc); 104 if (ret) 105 dev_err(&rproc->dev, "Boot failed: %d\n", ret); 106 } else if (sysfs_streq(buf, "stop")) { 107 if (rproc->state != RPROC_RUNNING) 108 return -EINVAL; 109 110 rproc_shutdown(rproc); 111 } else { 112 dev_err(&rproc->dev, "Unrecognised option: %s\n", buf); 113 ret = -EINVAL; 114 } 115 return ret ? ret : count; 116 } 117 static DEVICE_ATTR_RW(state); 118 119 static struct attribute *rproc_attrs[] = { 120 &dev_attr_firmware.attr, 121 &dev_attr_state.attr, 122 NULL 123 }; 124 125 static const struct attribute_group rproc_devgroup = { 126 .attrs = rproc_attrs 127 }; 128 129 static const struct attribute_group *rproc_devgroups[] = { 130 &rproc_devgroup, 131 NULL 132 }; 133 134 struct class rproc_class = { 135 .name = "remoteproc", 136 .dev_groups = rproc_devgroups, 137 }; 138 139 int __init rproc_init_sysfs(void) 140 { 141 /* create remoteproc device class for sysfs */ 142 int err = class_register(&rproc_class); 143 144 if (err) 145 pr_err("remoteproc: unable to register class\n"); 146 return err; 147 } 148 149 void __exit rproc_exit_sysfs(void) 150 { 151 class_unregister(&rproc_class); 152 } 153