xref: /linux/drivers/soundwire/debugfs.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright(c) 2017-2019 Intel Corporation.
3 
4 #include <linux/cleanup.h>
5 #include <linux/device.h>
6 #include <linux/debugfs.h>
7 #include <linux/firmware.h>
8 #include <linux/mod_devicetable.h>
9 #include <linux/pm_runtime.h>
10 #include <linux/slab.h>
11 #include <linux/soundwire/sdw.h>
12 #include <linux/soundwire/sdw_registers.h>
13 #include "bus.h"
14 
15 static struct dentry *sdw_debugfs_root;
16 
17 void sdw_bus_debugfs_init(struct sdw_bus *bus)
18 {
19 	char name[16];
20 
21 	if (!sdw_debugfs_root)
22 		return;
23 
24 	/* create the debugfs master-N */
25 	snprintf(name, sizeof(name), "master-%d-%d", bus->controller_id, bus->link_id);
26 	bus->debugfs = debugfs_create_dir(name, sdw_debugfs_root);
27 }
28 
29 void sdw_bus_debugfs_exit(struct sdw_bus *bus)
30 {
31 	debugfs_remove_recursive(bus->debugfs);
32 }
33 
34 #define RD_BUF (3 * PAGE_SIZE)
35 
36 static ssize_t sdw_sprintf(struct sdw_slave *slave,
37 			   char *buf, size_t pos, unsigned int reg)
38 {
39 	int value;
40 
41 	value = sdw_read_no_pm(slave, reg);
42 
43 	if (value < 0)
44 		return scnprintf(buf + pos, RD_BUF - pos, "%3x\tXX\n", reg);
45 	else
46 		return scnprintf(buf + pos, RD_BUF - pos,
47 				"%3x\t%2x\n", reg, value);
48 }
49 
50 static int sdw_slave_reg_show(struct seq_file *s_file, void *data)
51 {
52 	struct sdw_slave *slave = s_file->private;
53 	ssize_t ret;
54 	int i, j;
55 
56 	char *buf __free(kfree) = kzalloc(RD_BUF, GFP_KERNEL);
57 	if (!buf)
58 		return -ENOMEM;
59 
60 	ret = pm_runtime_get_sync(&slave->dev);
61 	if (ret < 0 && ret != -EACCES) {
62 		pm_runtime_put_noidle(&slave->dev);
63 		return ret;
64 	}
65 
66 	ret = scnprintf(buf, RD_BUF, "Register  Value\n");
67 
68 	/* DP0 non-banked registers */
69 	ret += scnprintf(buf + ret, RD_BUF - ret, "\nDP0\n");
70 	for (i = SDW_DP0_INT; i <= SDW_DP0_PREPARECTRL; i++)
71 		ret += sdw_sprintf(slave, buf, ret, i);
72 
73 	/* DP0 Bank 0 registers */
74 	ret += scnprintf(buf + ret, RD_BUF - ret, "Bank0\n");
75 	ret += sdw_sprintf(slave, buf, ret, SDW_DP0_CHANNELEN);
76 	for (i = SDW_DP0_SAMPLECTRL1; i <= SDW_DP0_LANECTRL; i++)
77 		ret += sdw_sprintf(slave, buf, ret, i);
78 
79 	/* DP0 Bank 1 registers */
80 	ret += scnprintf(buf + ret, RD_BUF - ret, "Bank1\n");
81 	ret += sdw_sprintf(slave, buf, ret,
82 			SDW_DP0_CHANNELEN + SDW_BANK1_OFFSET);
83 	for (i = SDW_DP0_SAMPLECTRL1 + SDW_BANK1_OFFSET;
84 			i <= SDW_DP0_LANECTRL + SDW_BANK1_OFFSET; i++)
85 		ret += sdw_sprintf(slave, buf, ret, i);
86 
87 	/* SCP registers */
88 	ret += scnprintf(buf + ret, RD_BUF - ret, "\nSCP\n");
89 	for (i = SDW_SCP_INT1; i <= SDW_SCP_BUS_CLOCK_BASE; i++)
90 		ret += sdw_sprintf(slave, buf, ret, i);
91 	for (i = SDW_SCP_DEVID_0; i <= SDW_SCP_DEVID_5; i++)
92 		ret += sdw_sprintf(slave, buf, ret, i);
93 	for (i = SDW_SCP_FRAMECTRL_B0; i <= SDW_SCP_BUSCLOCK_SCALE_B0; i++)
94 		ret += sdw_sprintf(slave, buf, ret, i);
95 	for (i = SDW_SCP_FRAMECTRL_B1; i <= SDW_SCP_BUSCLOCK_SCALE_B1; i++)
96 		ret += sdw_sprintf(slave, buf, ret, i);
97 	for (i = SDW_SCP_PHY_OUT_CTRL_0; i <= SDW_SCP_PHY_OUT_CTRL_7; i++)
98 		ret += sdw_sprintf(slave, buf, ret, i);
99 
100 
101 	/*
102 	 * SCP Bank 0/1 registers are read-only and cannot be
103 	 * retrieved from the Slave. The Master typically keeps track
104 	 * of the current frame size so the information can be found
105 	 * in other places
106 	 */
107 
108 	/* DP1..14 registers */
109 	for (i = 1; SDW_VALID_PORT_RANGE(i); i++) {
110 
111 		/* DPi registers */
112 		ret += scnprintf(buf + ret, RD_BUF - ret, "\nDP%d\n", i);
113 		for (j = SDW_DPN_INT(i); j <= SDW_DPN_PREPARECTRL(i); j++)
114 			ret += sdw_sprintf(slave, buf, ret, j);
115 
116 		/* DPi Bank0 registers */
117 		ret += scnprintf(buf + ret, RD_BUF - ret, "Bank0\n");
118 		for (j = SDW_DPN_CHANNELEN_B0(i);
119 		     j <= SDW_DPN_LANECTRL_B0(i); j++)
120 			ret += sdw_sprintf(slave, buf, ret, j);
121 
122 		/* DPi Bank1 registers */
123 		ret += scnprintf(buf + ret, RD_BUF - ret, "Bank1\n");
124 		for (j = SDW_DPN_CHANNELEN_B1(i);
125 		     j <= SDW_DPN_LANECTRL_B1(i); j++)
126 			ret += sdw_sprintf(slave, buf, ret, j);
127 	}
128 
129 	seq_printf(s_file, "%s", buf);
130 
131 	pm_runtime_mark_last_busy(&slave->dev);
132 	pm_runtime_put(&slave->dev);
133 
134 	return 0;
135 }
136 DEFINE_SHOW_ATTRIBUTE(sdw_slave_reg);
137 
138 #define MAX_CMD_BYTES 256
139 
140 static int cmd;
141 static u32 start_addr;
142 static size_t num_bytes;
143 static u8 read_buffer[MAX_CMD_BYTES];
144 static char *firmware_file;
145 
146 static int set_command(void *data, u64 value)
147 {
148 	struct sdw_slave *slave = data;
149 
150 	if (value > 1)
151 		return -EINVAL;
152 
153 	/* Userspace changed the hardware state behind the kernel's back */
154 	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
155 
156 	dev_dbg(&slave->dev, "command: %s\n", value ? "read" : "write");
157 	cmd = value;
158 
159 	return 0;
160 }
161 DEFINE_DEBUGFS_ATTRIBUTE(set_command_fops, NULL,
162 			 set_command, "%llu\n");
163 
164 static int set_start_address(void *data, u64 value)
165 {
166 	struct sdw_slave *slave = data;
167 
168 	/* Userspace changed the hardware state behind the kernel's back */
169 	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
170 
171 	dev_dbg(&slave->dev, "start address %#llx\n", value);
172 
173 	start_addr = value;
174 
175 	return 0;
176 }
177 DEFINE_DEBUGFS_ATTRIBUTE(set_start_address_fops, NULL,
178 			 set_start_address, "%llu\n");
179 
180 static int set_num_bytes(void *data, u64 value)
181 {
182 	struct sdw_slave *slave = data;
183 
184 	if (value == 0 || value > MAX_CMD_BYTES)
185 		return -EINVAL;
186 
187 	/* Userspace changed the hardware state behind the kernel's back */
188 	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
189 
190 	dev_dbg(&slave->dev, "number of bytes %lld\n", value);
191 
192 	num_bytes = value;
193 
194 	return 0;
195 }
196 DEFINE_DEBUGFS_ATTRIBUTE(set_num_bytes_fops, NULL,
197 			 set_num_bytes, "%llu\n");
198 
199 static int cmd_go(void *data, u64 value)
200 {
201 	struct sdw_slave *slave = data;
202 	int ret;
203 
204 	if (value != 1)
205 		return -EINVAL;
206 
207 	/* one last check */
208 	if (start_addr > SDW_REG_MAX ||
209 	    num_bytes == 0 || num_bytes > MAX_CMD_BYTES)
210 		return -EINVAL;
211 
212 	ret = pm_runtime_get_sync(&slave->dev);
213 	if (ret < 0 && ret != -EACCES) {
214 		pm_runtime_put_noidle(&slave->dev);
215 		return ret;
216 	}
217 
218 	/* Userspace changed the hardware state behind the kernel's back */
219 	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
220 
221 	dev_dbg(&slave->dev, "starting command\n");
222 
223 	if (cmd == 0) {
224 		const struct firmware *fw;
225 
226 		ret = request_firmware(&fw, firmware_file, &slave->dev);
227 		if (ret < 0) {
228 			dev_err(&slave->dev, "firmware %s not found\n", firmware_file);
229 			goto out;
230 		}
231 
232 		if (fw->size != num_bytes) {
233 			dev_err(&slave->dev,
234 				"firmware %s: unexpected size %zd, desired %zd\n",
235 				firmware_file, fw->size, num_bytes);
236 			release_firmware(fw);
237 			goto out;
238 		}
239 
240 		ret = sdw_nwrite_no_pm(slave, start_addr, num_bytes, fw->data);
241 		release_firmware(fw);
242 	} else {
243 		ret = sdw_nread_no_pm(slave, start_addr, num_bytes, read_buffer);
244 	}
245 
246 	dev_dbg(&slave->dev, "command completed %d\n", ret);
247 
248 out:
249 	pm_runtime_mark_last_busy(&slave->dev);
250 	pm_runtime_put(&slave->dev);
251 
252 	return ret;
253 }
254 DEFINE_DEBUGFS_ATTRIBUTE(cmd_go_fops, NULL,
255 			 cmd_go, "%llu\n");
256 
257 #define MAX_LINE_LEN 128
258 
259 static int read_buffer_show(struct seq_file *s_file, void *data)
260 {
261 	char buf[MAX_LINE_LEN];
262 	int i;
263 
264 	if (num_bytes == 0 || num_bytes > MAX_CMD_BYTES)
265 		return -EINVAL;
266 
267 	for (i = 0; i < num_bytes; i++) {
268 		scnprintf(buf, MAX_LINE_LEN, "address %#x val 0x%02x\n",
269 			  start_addr + i, read_buffer[i]);
270 		seq_printf(s_file, "%s", buf);
271 	}
272 
273 	return 0;
274 }
275 DEFINE_SHOW_ATTRIBUTE(read_buffer);
276 
277 void sdw_slave_debugfs_init(struct sdw_slave *slave)
278 {
279 	struct dentry *master;
280 	struct dentry *d;
281 	char name[32];
282 
283 	master = slave->bus->debugfs;
284 
285 	/* create the debugfs slave-name */
286 	snprintf(name, sizeof(name), "%s", dev_name(&slave->dev));
287 	d = debugfs_create_dir(name, master);
288 
289 	debugfs_create_file("registers", 0400, d, slave, &sdw_slave_reg_fops);
290 
291 	/* interface to send arbitrary commands */
292 	debugfs_create_file("command", 0200, d, slave, &set_command_fops);
293 	debugfs_create_file("start_address", 0200, d, slave, &set_start_address_fops);
294 	debugfs_create_file("num_bytes", 0200, d, slave, &set_num_bytes_fops);
295 	debugfs_create_file("go", 0200, d, slave, &cmd_go_fops);
296 
297 	debugfs_create_file("read_buffer", 0400, d, slave, &read_buffer_fops);
298 	firmware_file = NULL;
299 	debugfs_create_str("firmware_file", 0200, d, &firmware_file);
300 
301 	slave->debugfs = d;
302 }
303 
304 void sdw_slave_debugfs_exit(struct sdw_slave *slave)
305 {
306 	debugfs_remove_recursive(slave->debugfs);
307 }
308 
309 void sdw_debugfs_init(void)
310 {
311 	sdw_debugfs_root = debugfs_create_dir("soundwire", NULL);
312 }
313 
314 void sdw_debugfs_exit(void)
315 {
316 	debugfs_remove_recursive(sdw_debugfs_root);
317 }
318