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 */
zynqmp_pm_argument_value(char * arg)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 */
get_pm_api_id(char * pm_api_req,u32 * pm_id)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
process_api_request(u32 pm_id,u64 * pm_api_arg,u32 * pm_api_ret)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 */
zynqmp_pm_debugfs_api_write(struct file * file,const char __user * ptr,size_t len,loff_t * off)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 */
zynqmp_pm_debugfs_api_read(struct file * file,char __user * ptr,size_t len,loff_t * off)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 */
zynqmp_pm_api_debugfs_init(void)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 */
zynqmp_pm_api_debugfs_exit(void)236 void zynqmp_pm_api_debugfs_exit(void)
237 {
238 debugfs_remove_recursive(firmware_debugfs_root);
239 }
240