drivers/firmware/xilinx/zynqmp-debug.c

   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@xilinx.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         const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
  89         u32 pm_api_version;
  90         int ret;
  91         struct zynqmp_pm_query_data qdata = {0};
  92
  93         switch (pm_id) {
  94         case PM_GET_API_VERSION:
  95                 ret = eemi_ops->get_api_version(&pm_api_version);
  96                 sprintf(debugfs_buf, "PM-API Version = %d.%d\n",
  97                         pm_api_version >> 16, pm_api_version & 0xffff);
  98                 break;
  99         case PM_QUERY_DATA:
 100                 qdata.qid = pm_api_arg[0];
 101                 qdata.arg1 = pm_api_arg[1];
 102                 qdata.arg2 = pm_api_arg[2];
 103                 qdata.arg3 = pm_api_arg[3];
 104
 105                 ret = eemi_ops->query_data(qdata, pm_api_ret);
 106                 if (ret)
 107                         break;
 108
 109                 switch (qdata.qid) {
 110                 case PM_QID_CLOCK_GET_NAME:
 111                         sprintf(debugfs_buf, "Clock name = %s\n",
 112                                 (char *)pm_api_ret);
 113                         break;
 114                 case PM_QID_CLOCK_GET_FIXEDFACTOR_PARAMS:
 115                         sprintf(debugfs_buf, "Multiplier = %d, Divider = %d\n",
 116                                 pm_api_ret[1], pm_api_ret[2]);
 117                         break;
 118                 default:
 119                         sprintf(debugfs_buf,
 120                                 "data[0] = 0x%08x\ndata[1] = 0x%08x\n data[2] = 0x%08x\ndata[3] = 0x%08x\n",
 121                                 pm_api_ret[0], pm_api_ret[1],
 122                                 pm_api_ret[2], pm_api_ret[3]);
 123                 }
 124                 break;
 125         default:
 126                 sprintf(debugfs_buf, "Unsupported PM-API request\n");
 127                 ret = -EINVAL;
 128         }
 129
 130         return ret;
 131 }
 132
 133 /**
 134  * zynqmp_pm_debugfs_api_write() - debugfs write function
 135  * @file:       User file
 136  * @ptr:        User entered PM-API string
 137  * @len:        Length of the userspace buffer
 138  * @off:        Offset within the file
 139  *
 140  * Used for triggering pm api functions by writing
 141  * echo <pm_api_id>     > /sys/kernel/debug/zynqmp_pm/power or
 142  * echo <pm_api_name>   > /sys/kernel/debug/zynqmp_pm/power
 143  *
 144  * Return: Number of bytes copied if PM-API request succeeds,
 145  *         the corresponding error code otherwise
 146  */
 147 static ssize_t zynqmp_pm_debugfs_api_write(struct file *file,
 148                                            const char __user *ptr, size_t len,
 149                                            loff_t *off)
 150 {
 151         char *kern_buff, *tmp_buff;
 152         char *pm_api_req;
 153         u32 pm_id = 0;
 154         u64 pm_api_arg[4] = {0, 0, 0, 0};
 155         /* Return values from PM APIs calls */
 156         u32 pm_api_ret[4] = {0, 0, 0, 0};
 157
 158         int ret;
 159         int i = 0;
 160
 161         strcpy(debugfs_buf, "");
 162
 163         if (*off != 0 || len <= 1 || len > PAGE_SIZE - 1)
 164                 return -EINVAL;
 165
 166         kern_buff = memdup_user_nul(ptr, len);
 167         if (IS_ERR(kern_buff))
 168                 return PTR_ERR(kern_buff);
 169         tmp_buff = kern_buff;
 170
 171         /* Read the API name from a user request */
 172         pm_api_req = strsep(&kern_buff, " ");
 173
 174         ret = get_pm_api_id(pm_api_req, &pm_id);
 175         if (ret < 0)
 176                 goto err;
 177
 178         /* Read node_id and arguments from the PM-API request */
 179         pm_api_req = strsep(&kern_buff, " ");
 180         while ((i < ARRAY_SIZE(pm_api_arg)) && pm_api_req) {
 181                 pm_api_arg[i++] = zynqmp_pm_argument_value(pm_api_req);
 182                 pm_api_req = strsep(&kern_buff, " ");
 183         }
 184
 185         ret = process_api_request(pm_id, pm_api_arg, pm_api_ret);
 186
 187 err:
 188         kfree(tmp_buff);
 189         if (ret)
 190                 return ret;
 191
 192         return len;
 193 }
 194
 195 /**
 196  * zynqmp_pm_debugfs_api_read() - debugfs read function
 197  * @file:       User file
 198  * @ptr:        Requested pm_api_version string
 199  * @len:        Length of the userspace buffer
 200  * @off:        Offset within the file
 201  *
 202  * Return: Length of the version string on success
 203  *         else error code
 204  */
 205 static ssize_t zynqmp_pm_debugfs_api_read(struct file *file, char __user *ptr,
 206                                           size_t len, loff_t *off)
 207 {
 208         return simple_read_from_buffer(ptr, len, off, debugfs_buf,
 209                                        strlen(debugfs_buf));
 210 }
 211
 212 /* Setup debugfs fops */
 213 static const struct file_operations fops_zynqmp_pm_dbgfs = {
 214         .owner = THIS_MODULE,
 215         .write = zynqmp_pm_debugfs_api_write,
 216         .read = zynqmp_pm_debugfs_api_read,
 217 };
 218
 219 /**
 220  * zynqmp_pm_api_debugfs_init - Initialize debugfs interface
 221  *
 222  * Return:      None
 223  */
 224 void zynqmp_pm_api_debugfs_init(void)
 225 {
 226         /* Initialize debugfs interface */
 227         firmware_debugfs_root = debugfs_create_dir("zynqmp-firmware", NULL);
 228         debugfs_create_file("pm", 0660, firmware_debugfs_root, NULL,
 229                             &fops_zynqmp_pm_dbgfs);
 230 }
 231
 232 /**
 233  * zynqmp_pm_api_debugfs_exit - Remove debugfs interface
 234  *
 235  * Return:      None
 236  */
 237 void zynqmp_pm_api_debugfs_exit(void)
 238 {
 239         debugfs_remove_recursive(firmware_debugfs_root);
 240 }