1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Xilinx Zynq MPSoC Firmware layer for debugfs APIs 4 * 5 * Copyright (C) 2014-2018 Xilinx, Inc. 6 * 7 * Michal Simek <michal.simek@amd.com> 8 * Davorin Mista <davorin.mista@aggios.com> 9 * Jolly Shah <jollys@xilinx.com> 10 * Rajan Vaja <rajanv@xilinx.com> 11 */ 12 13 #include <linux/compiler.h> 14 #include <linux/module.h> 15 #include <linux/slab.h> 16 #include <linux/debugfs.h> 17 #include <linux/uaccess.h> 18 19 #include <linux/firmware/xlnx-zynqmp.h> 20 #include "zynqmp-debug.h" 21 22 #define PM_API_NAME_LEN 50 23 24 struct pm_api_info { 25 u32 api_id; 26 char api_name[PM_API_NAME_LEN]; 27 char api_name_len; 28 }; 29 30 static char debugfs_buf[PAGE_SIZE]; 31 32 #define PM_API(id) {id, #id, strlen(#id)} 33 static struct pm_api_info pm_api_list[] = { 34 PM_API(PM_GET_API_VERSION), 35 PM_API(PM_QUERY_DATA), 36 }; 37 38 static struct dentry *firmware_debugfs_root; 39 40 /** 41 * zynqmp_pm_argument_value() - Extract argument value from a PM-API request 42 * @arg: Entered PM-API argument in string format 43 * 44 * Return: Argument value in unsigned integer format on success 45 * 0 otherwise 46 */ 47 static u64 zynqmp_pm_argument_value(char *arg) 48 { 49 u64 value; 50 51 if (!arg) 52 return 0; 53 54 if (!kstrtou64(arg, 0, &value)) 55 return value; 56 57 return 0; 58 } 59 60 /** 61 * get_pm_api_id() - Extract API-ID from a PM-API request 62 * @pm_api_req: Entered PM-API argument in string format 63 * @pm_id: API-ID 64 * 65 * Return: 0 on success else error code 66 */ 67 static int get_pm_api_id(char *pm_api_req, u32 *pm_id) 68 { 69 int i; 70 71 for (i = 0; i < ARRAY_SIZE(pm_api_list) ; i++) { 72 if (!strncasecmp(pm_api_req, pm_api_list[i].api_name, 73 pm_api_list[i].api_name_len)) { 74 *pm_id = pm_api_list[i].api_id; 75 break; 76 } 77 } 78 79 /* If no name was entered look for PM-API ID instead */ 80 if (i == ARRAY_SIZE(pm_api_list) && kstrtouint(pm_api_req, 10, pm_id)) 81 return -EINVAL; 82 83 return 0; 84 } 85 86 static int process_api_request(u32 pm_id, u64 *pm_api_arg, u32 *pm_api_ret) 87 { 88 u32 pm_api_version; 89 int ret; 90 struct zynqmp_pm_query_data qdata = {0}; 91 92 switch (pm_id) { 93 case PM_GET_API_VERSION: 94 ret = zynqmp_pm_get_api_version(&pm_api_version); 95 sprintf(debugfs_buf, "PM-API Version = %d.%d\n", 96 pm_api_version >> 16, pm_api_version & 0xffff); 97 break; 98 case PM_QUERY_DATA: 99 qdata.qid = pm_api_arg[0]; 100 qdata.arg1 = pm_api_arg[1]; 101 qdata.arg2 = pm_api_arg[2]; 102 qdata.arg3 = pm_api_arg[3]; 103 104 ret = zynqmp_pm_query_data(qdata, pm_api_ret); 105 if (ret) 106 break; 107 108 switch (qdata.qid) { 109 case PM_QID_CLOCK_GET_NAME: 110 sprintf(debugfs_buf, "Clock name = %s\n", 111 (char *)pm_api_ret); 112 break; 113 case PM_QID_CLOCK_GET_FIXEDFACTOR_PARAMS: 114 sprintf(debugfs_buf, "Multiplier = %d, Divider = %d\n", 115 pm_api_ret[1], pm_api_ret[2]); 116 break; 117 default: 118 sprintf(debugfs_buf, 119 "data[0] = 0x%08x\ndata[1] = 0x%08x\n data[2] = 0x%08x\ndata[3] = 0x%08x\n", 120 pm_api_ret[0], pm_api_ret[1], 121 pm_api_ret[2], pm_api_ret[3]); 122 } 123 break; 124 default: 125 sprintf(debugfs_buf, "Unsupported PM-API request\n"); 126 ret = -EINVAL; 127 } 128 129 return ret; 130 } 131 132 /** 133 * zynqmp_pm_debugfs_api_write() - debugfs write function 134 * @file: User file 135 * @ptr: User entered PM-API string 136 * @len: Length of the userspace buffer 137 * @off: Offset within the file 138 * 139 * Used for triggering pm api functions by writing 140 * echo <pm_api_id> > /sys/kernel/debug/zynqmp_pm/power or 141 * echo <pm_api_name> > /sys/kernel/debug/zynqmp_pm/power 142 * 143 * Return: Number of bytes copied if PM-API request succeeds, 144 * the corresponding error code otherwise 145 */ 146 static ssize_t zynqmp_pm_debugfs_api_write(struct file *file, 147 const char __user *ptr, size_t len, 148 loff_t *off) 149 { 150 char *kern_buff, *tmp_buff; 151 char *pm_api_req; 152 u32 pm_id = 0; 153 u64 pm_api_arg[4] = {0, 0, 0, 0}; 154 /* Return values from PM APIs calls */ 155 u32 pm_api_ret[4] = {0, 0, 0, 0}; 156 157 int ret; 158 int i = 0; 159 160 strcpy(debugfs_buf, ""); 161 162 if (*off != 0 || len <= 1 || len > PAGE_SIZE - 1) 163 return -EINVAL; 164 165 kern_buff = memdup_user_nul(ptr, len); 166 if (IS_ERR(kern_buff)) 167 return PTR_ERR(kern_buff); 168 tmp_buff = kern_buff; 169 170 /* Read the API name from a user request */ 171 pm_api_req = strsep(&kern_buff, " "); 172 173 ret = get_pm_api_id(pm_api_req, &pm_id); 174 if (ret < 0) 175 goto err; 176 177 /* Read node_id and arguments from the PM-API request */ 178 pm_api_req = strsep(&kern_buff, " "); 179 while ((i < ARRAY_SIZE(pm_api_arg)) && pm_api_req) { 180 pm_api_arg[i++] = zynqmp_pm_argument_value(pm_api_req); 181 pm_api_req = strsep(&kern_buff, " "); 182 } 183 184 ret = process_api_request(pm_id, pm_api_arg, pm_api_ret); 185 186 err: 187 kfree(tmp_buff); 188 if (ret) 189 return ret; 190 191 return len; 192 } 193 194 /** 195 * zynqmp_pm_debugfs_api_read() - debugfs read function 196 * @file: User file 197 * @ptr: Requested pm_api_version string 198 * @len: Length of the userspace buffer 199 * @off: Offset within the file 200 * 201 * Return: Length of the version string on success 202 * else error code 203 */ 204 static ssize_t zynqmp_pm_debugfs_api_read(struct file *file, char __user *ptr, 205 size_t len, loff_t *off) 206 { 207 return simple_read_from_buffer(ptr, len, off, debugfs_buf, 208 strlen(debugfs_buf)); 209 } 210 211 /* Setup debugfs fops */ 212 static const struct file_operations fops_zynqmp_pm_dbgfs = { 213 .owner = THIS_MODULE, 214 .write = zynqmp_pm_debugfs_api_write, 215 .read = zynqmp_pm_debugfs_api_read, 216 }; 217 218 /** 219 * zynqmp_pm_api_debugfs_init - Initialize debugfs interface 220 * 221 * Return: None 222 */ 223 void zynqmp_pm_api_debugfs_init(void) 224 { 225 /* Initialize debugfs interface */ 226 firmware_debugfs_root = debugfs_create_dir("zynqmp-firmware", NULL); 227 debugfs_create_file("pm", 0660, firmware_debugfs_root, NULL, 228 &fops_zynqmp_pm_dbgfs); 229 } 230 231 /** 232 * zynqmp_pm_api_debugfs_exit - Remove debugfs interface 233 * 234 * Return: None 235 */ 236 void zynqmp_pm_api_debugfs_exit(void) 237 { 238 debugfs_remove_recursive(firmware_debugfs_root); 239 } 240