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(s: arg, base: 0, res: &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(s1: pm_api_req, s2: pm_api_list[i].api_name, |
73 | n: 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(s: pm_api_req, base: 10, res: 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(version: &pm_api_version); |
95 | sprintf(buf: debugfs_buf, fmt: "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, out: pm_api_ret); |
105 | if (ret) |
106 | break; |
107 | |
108 | switch (qdata.qid) { |
109 | case PM_QID_CLOCK_GET_NAME: |
110 | sprintf(buf: debugfs_buf, fmt: "Clock name = %s\n" , |
111 | (char *)pm_api_ret); |
112 | break; |
113 | case PM_QID_CLOCK_GET_FIXEDFACTOR_PARAMS: |
114 | sprintf(buf: debugfs_buf, fmt: "Multiplier = %d, Divider = %d\n" , |
115 | pm_api_ret[1], pm_api_ret[2]); |
116 | break; |
117 | default: |
118 | sprintf(buf: debugfs_buf, |
119 | fmt: "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(buf: debugfs_buf, fmt: "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(p: debugfs_buf, q: "" ); |
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(ptr: kern_buff)) |
167 | return PTR_ERR(ptr: 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: &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(arg: 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(objp: 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(to: ptr, count: len, ppos: off, from: 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(name: "zynqmp-firmware" , NULL); |
227 | debugfs_create_file(name: "pm" , mode: 0660, parent: firmware_debugfs_root, NULL, |
228 | fops: &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(dentry: firmware_debugfs_root); |
239 | } |
240 | |