1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
4 */
5
6#include <linux/delay.h>
7#include <linux/slab.h>
8#include <linux/sched/types.h>
9
10#include <media/cec-pin.h>
11#include "cec-pin-priv.h"
12
13struct cec_error_inj_cmd {
14	unsigned int mode_offset;
15	int arg_idx;
16	const char *cmd;
17};
18
19static const struct cec_error_inj_cmd cec_error_inj_cmds[] = {
20	{ CEC_ERROR_INJ_RX_NACK_OFFSET, -1, "rx-nack" },
21	{ CEC_ERROR_INJ_RX_LOW_DRIVE_OFFSET,
22	  CEC_ERROR_INJ_RX_LOW_DRIVE_ARG_IDX, "rx-low-drive" },
23	{ CEC_ERROR_INJ_RX_ADD_BYTE_OFFSET, -1, "rx-add-byte" },
24	{ CEC_ERROR_INJ_RX_REMOVE_BYTE_OFFSET, -1, "rx-remove-byte" },
25	{ CEC_ERROR_INJ_RX_ARB_LOST_OFFSET,
26	  CEC_ERROR_INJ_RX_ARB_LOST_ARG_IDX, "rx-arb-lost" },
27
28	{ CEC_ERROR_INJ_TX_NO_EOM_OFFSET, -1, "tx-no-eom" },
29	{ CEC_ERROR_INJ_TX_EARLY_EOM_OFFSET, -1, "tx-early-eom" },
30	{ CEC_ERROR_INJ_TX_ADD_BYTES_OFFSET,
31	  CEC_ERROR_INJ_TX_ADD_BYTES_ARG_IDX, "tx-add-bytes" },
32	{ CEC_ERROR_INJ_TX_REMOVE_BYTE_OFFSET, -1, "tx-remove-byte" },
33	{ CEC_ERROR_INJ_TX_SHORT_BIT_OFFSET,
34	  CEC_ERROR_INJ_TX_SHORT_BIT_ARG_IDX, "tx-short-bit" },
35	{ CEC_ERROR_INJ_TX_LONG_BIT_OFFSET,
36	  CEC_ERROR_INJ_TX_LONG_BIT_ARG_IDX, "tx-long-bit" },
37	{ CEC_ERROR_INJ_TX_CUSTOM_BIT_OFFSET,
38	  CEC_ERROR_INJ_TX_CUSTOM_BIT_ARG_IDX, "tx-custom-bit" },
39	{ CEC_ERROR_INJ_TX_SHORT_START_OFFSET, -1, "tx-short-start" },
40	{ CEC_ERROR_INJ_TX_LONG_START_OFFSET, -1, "tx-long-start" },
41	{ CEC_ERROR_INJ_TX_CUSTOM_START_OFFSET, -1, "tx-custom-start" },
42	{ CEC_ERROR_INJ_TX_LAST_BIT_OFFSET,
43	  CEC_ERROR_INJ_TX_LAST_BIT_ARG_IDX, "tx-last-bit" },
44	{ CEC_ERROR_INJ_TX_LOW_DRIVE_OFFSET,
45	  CEC_ERROR_INJ_TX_LOW_DRIVE_ARG_IDX, "tx-low-drive" },
46	{ 0, -1, NULL }
47};
48
49u16 cec_pin_rx_error_inj(struct cec_pin *pin)
50{
51	u16 cmd = CEC_ERROR_INJ_OP_ANY;
52
53	/* Only when 18 bits have been received do we have a valid cmd */
54	if (!(pin->error_inj[cmd] & CEC_ERROR_INJ_RX_MASK) &&
55	    pin->rx_bit >= 18)
56		cmd = pin->rx_msg.msg[1];
57	return (pin->error_inj[cmd] & CEC_ERROR_INJ_RX_MASK) ? cmd :
58		CEC_ERROR_INJ_OP_ANY;
59}
60
61u16 cec_pin_tx_error_inj(struct cec_pin *pin)
62{
63	u16 cmd = CEC_ERROR_INJ_OP_ANY;
64
65	if (!(pin->error_inj[cmd] & CEC_ERROR_INJ_TX_MASK) &&
66	    pin->tx_msg.len > 1)
67		cmd = pin->tx_msg.msg[1];
68	return (pin->error_inj[cmd] & CEC_ERROR_INJ_TX_MASK) ? cmd :
69		CEC_ERROR_INJ_OP_ANY;
70}
71
72bool cec_pin_error_inj_parse_line(struct cec_adapter *adap, char *line)
73{
74	static const char *delims = " \t\r";
75	struct cec_pin *pin = adap->pin;
76	unsigned int i;
77	bool has_pos = false;
78	char *p = line;
79	char *token;
80	char *comma;
81	u64 *error;
82	u8 *args;
83	bool has_op;
84	u8 op;
85	u8 mode;
86	u8 pos;
87
88	p = skip_spaces(p);
89	token = strsep(&p, delims);
90	if (!strcmp(token, "clear")) {
91		memset(pin->error_inj, 0, sizeof(pin->error_inj));
92		pin->rx_toggle = pin->tx_toggle = false;
93		pin->tx_ignore_nack_until_eom = false;
94		pin->tx_custom_pulse = false;
95		pin->tx_custom_low_usecs = CEC_TIM_CUSTOM_DEFAULT;
96		pin->tx_custom_high_usecs = CEC_TIM_CUSTOM_DEFAULT;
97		return true;
98	}
99	if (!strcmp(token, "rx-clear")) {
100		for (i = 0; i <= CEC_ERROR_INJ_OP_ANY; i++)
101			pin->error_inj[i] &= ~CEC_ERROR_INJ_RX_MASK;
102		pin->rx_toggle = false;
103		return true;
104	}
105	if (!strcmp(token, "tx-clear")) {
106		for (i = 0; i <= CEC_ERROR_INJ_OP_ANY; i++)
107			pin->error_inj[i] &= ~CEC_ERROR_INJ_TX_MASK;
108		pin->tx_toggle = false;
109		pin->tx_ignore_nack_until_eom = false;
110		pin->tx_custom_pulse = false;
111		pin->tx_custom_low_usecs = CEC_TIM_CUSTOM_DEFAULT;
112		pin->tx_custom_high_usecs = CEC_TIM_CUSTOM_DEFAULT;
113		return true;
114	}
115	if (!strcmp(token, "tx-ignore-nack-until-eom")) {
116		pin->tx_ignore_nack_until_eom = true;
117		return true;
118	}
119	if (!strcmp(token, "tx-custom-pulse")) {
120		pin->tx_custom_pulse = true;
121		cec_pin_start_timer(pin);
122		return true;
123	}
124	if (!p)
125		return false;
126
127	p = skip_spaces(p);
128	if (!strcmp(token, "tx-custom-low-usecs")) {
129		u32 usecs;
130
131		if (kstrtou32(p, 0, &usecs) || usecs > 10000000)
132			return false;
133		pin->tx_custom_low_usecs = usecs;
134		return true;
135	}
136	if (!strcmp(token, "tx-custom-high-usecs")) {
137		u32 usecs;
138
139		if (kstrtou32(p, 0, &usecs) || usecs > 10000000)
140			return false;
141		pin->tx_custom_high_usecs = usecs;
142		return true;
143	}
144
145	comma = strchr(token, ',');
146	if (comma)
147		*comma++ = '\0';
148	if (!strcmp(token, "any")) {
149		has_op = false;
150		error = pin->error_inj + CEC_ERROR_INJ_OP_ANY;
151		args = pin->error_inj_args[CEC_ERROR_INJ_OP_ANY];
152	} else if (!kstrtou8(token, 0, &op)) {
153		has_op = true;
154		error = pin->error_inj + op;
155		args = pin->error_inj_args[op];
156	} else {
157		return false;
158	}
159
160	mode = CEC_ERROR_INJ_MODE_ONCE;
161	if (comma) {
162		if (!strcmp(comma, "off"))
163			mode = CEC_ERROR_INJ_MODE_OFF;
164		else if (!strcmp(comma, "once"))
165			mode = CEC_ERROR_INJ_MODE_ONCE;
166		else if (!strcmp(comma, "always"))
167			mode = CEC_ERROR_INJ_MODE_ALWAYS;
168		else if (!strcmp(comma, "toggle"))
169			mode = CEC_ERROR_INJ_MODE_TOGGLE;
170		else
171			return false;
172	}
173
174	token = strsep(&p, delims);
175	if (p) {
176		p = skip_spaces(p);
177		has_pos = !kstrtou8(p, 0, &pos);
178	}
179
180	if (!strcmp(token, "clear")) {
181		*error = 0;
182		return true;
183	}
184	if (!strcmp(token, "rx-clear")) {
185		*error &= ~CEC_ERROR_INJ_RX_MASK;
186		return true;
187	}
188	if (!strcmp(token, "tx-clear")) {
189		*error &= ~CEC_ERROR_INJ_TX_MASK;
190		return true;
191	}
192
193	for (i = 0; cec_error_inj_cmds[i].cmd; i++) {
194		const char *cmd = cec_error_inj_cmds[i].cmd;
195		unsigned int mode_offset;
196		u64 mode_mask;
197		int arg_idx;
198		bool is_bit_pos = true;
199
200		if (strcmp(token, cmd))
201			continue;
202
203		mode_offset = cec_error_inj_cmds[i].mode_offset;
204		mode_mask = CEC_ERROR_INJ_MODE_MASK << mode_offset;
205		arg_idx = cec_error_inj_cmds[i].arg_idx;
206
207		if (mode_offset == CEC_ERROR_INJ_RX_ARB_LOST_OFFSET) {
208			if (has_op)
209				return false;
210			if (!has_pos)
211				pos = 0x0f;
212			is_bit_pos = false;
213		} else if (mode_offset == CEC_ERROR_INJ_TX_ADD_BYTES_OFFSET) {
214			if (!has_pos || !pos)
215				return false;
216			is_bit_pos = false;
217		}
218
219		if (arg_idx >= 0 && is_bit_pos) {
220			if (!has_pos || pos >= 160)
221				return false;
222			if (has_op && pos < 10 + 8)
223				return false;
224			/* Invalid bit position may not be the Ack bit */
225			if ((mode_offset == CEC_ERROR_INJ_TX_SHORT_BIT_OFFSET ||
226			     mode_offset == CEC_ERROR_INJ_TX_LONG_BIT_OFFSET ||
227			     mode_offset == CEC_ERROR_INJ_TX_CUSTOM_BIT_OFFSET) &&
228			    (pos % 10) == 9)
229				return false;
230		}
231		*error &= ~mode_mask;
232		*error |= (u64)mode << mode_offset;
233		if (arg_idx >= 0)
234			args[arg_idx] = pos;
235		return true;
236	}
237	return false;
238}
239
240static void cec_pin_show_cmd(struct seq_file *sf, u32 cmd, u8 mode)
241{
242	if (cmd == CEC_ERROR_INJ_OP_ANY)
243		seq_puts(sf, "any,");
244	else
245		seq_printf(sf, "0x%02x,", cmd);
246	switch (mode) {
247	case CEC_ERROR_INJ_MODE_ONCE:
248		seq_puts(sf, "once ");
249		break;
250	case CEC_ERROR_INJ_MODE_ALWAYS:
251		seq_puts(sf, "always ");
252		break;
253	case CEC_ERROR_INJ_MODE_TOGGLE:
254		seq_puts(sf, "toggle ");
255		break;
256	default:
257		seq_puts(sf, "off ");
258		break;
259	}
260}
261
262int cec_pin_error_inj_show(struct cec_adapter *adap, struct seq_file *sf)
263{
264	struct cec_pin *pin = adap->pin;
265	unsigned int i, j;
266
267	seq_puts(sf, "# Clear error injections:\n");
268	seq_puts(sf, "#   clear          clear all rx and tx error injections\n");
269	seq_puts(sf, "#   rx-clear       clear all rx error injections\n");
270	seq_puts(sf, "#   tx-clear       clear all tx error injections\n");
271	seq_puts(sf, "#   <op> clear     clear all rx and tx error injections for <op>\n");
272	seq_puts(sf, "#   <op> rx-clear  clear all rx error injections for <op>\n");
273	seq_puts(sf, "#   <op> tx-clear  clear all tx error injections for <op>\n");
274	seq_puts(sf, "#\n");
275	seq_puts(sf, "# RX error injection:\n");
276	seq_puts(sf, "#   <op>[,<mode>] rx-nack              NACK the message instead of sending an ACK\n");
277	seq_puts(sf, "#   <op>[,<mode>] rx-low-drive <bit>   force a low-drive condition at this bit position\n");
278	seq_puts(sf, "#   <op>[,<mode>] rx-add-byte          add a spurious byte to the received CEC message\n");
279	seq_puts(sf, "#   <op>[,<mode>] rx-remove-byte       remove the last byte from the received CEC message\n");
280	seq_puts(sf, "#    any[,<mode>] rx-arb-lost [<poll>] generate a POLL message to trigger an arbitration lost\n");
281	seq_puts(sf, "#\n");
282	seq_puts(sf, "# TX error injection settings:\n");
283	seq_puts(sf, "#   tx-ignore-nack-until-eom           ignore early NACKs until EOM\n");
284	seq_puts(sf, "#   tx-custom-low-usecs <usecs>        define the 'low' time for the custom pulse\n");
285	seq_puts(sf, "#   tx-custom-high-usecs <usecs>       define the 'high' time for the custom pulse\n");
286	seq_puts(sf, "#   tx-custom-pulse                    transmit the custom pulse once the bus is idle\n");
287	seq_puts(sf, "#\n");
288	seq_puts(sf, "# TX error injection:\n");
289	seq_puts(sf, "#   <op>[,<mode>] tx-no-eom            don't set the EOM bit\n");
290	seq_puts(sf, "#   <op>[,<mode>] tx-early-eom         set the EOM bit one byte too soon\n");
291	seq_puts(sf, "#   <op>[,<mode>] tx-add-bytes <num>   append <num> (1-255) spurious bytes to the message\n");
292	seq_puts(sf, "#   <op>[,<mode>] tx-remove-byte       drop the last byte from the message\n");
293	seq_puts(sf, "#   <op>[,<mode>] tx-short-bit <bit>   make this bit shorter than allowed\n");
294	seq_puts(sf, "#   <op>[,<mode>] tx-long-bit <bit>    make this bit longer than allowed\n");
295	seq_puts(sf, "#   <op>[,<mode>] tx-custom-bit <bit>  send the custom pulse instead of this bit\n");
296	seq_puts(sf, "#   <op>[,<mode>] tx-short-start       send a start pulse that's too short\n");
297	seq_puts(sf, "#   <op>[,<mode>] tx-long-start        send a start pulse that's too long\n");
298	seq_puts(sf, "#   <op>[,<mode>] tx-custom-start      send the custom pulse instead of the start pulse\n");
299	seq_puts(sf, "#   <op>[,<mode>] tx-last-bit <bit>    stop sending after this bit\n");
300	seq_puts(sf, "#   <op>[,<mode>] tx-low-drive <bit>   force a low-drive condition at this bit position\n");
301	seq_puts(sf, "#\n");
302	seq_puts(sf, "# <op>       CEC message opcode (0-255) or 'any'\n");
303	seq_puts(sf, "# <mode>     'once' (default), 'always', 'toggle' or 'off'\n");
304	seq_puts(sf, "# <bit>      CEC message bit (0-159)\n");
305	seq_puts(sf, "#            10 bits per 'byte': bits 0-7: data, bit 8: EOM, bit 9: ACK\n");
306	seq_puts(sf, "# <poll>     CEC poll message used to test arbitration lost (0x00-0xff, default 0x0f)\n");
307	seq_puts(sf, "# <usecs>    microseconds (0-10000000, default 1000)\n");
308
309	seq_puts(sf, "\nclear\n");
310
311	for (i = 0; i < ARRAY_SIZE(pin->error_inj); i++) {
312		u64 e = pin->error_inj[i];
313
314		for (j = 0; cec_error_inj_cmds[j].cmd; j++) {
315			const char *cmd = cec_error_inj_cmds[j].cmd;
316			unsigned int mode;
317			unsigned int mode_offset;
318			int arg_idx;
319
320			mode_offset = cec_error_inj_cmds[j].mode_offset;
321			arg_idx = cec_error_inj_cmds[j].arg_idx;
322			mode = (e >> mode_offset) & CEC_ERROR_INJ_MODE_MASK;
323			if (!mode)
324				continue;
325			cec_pin_show_cmd(sf, i, mode);
326			seq_puts(sf, cmd);
327			if (arg_idx >= 0)
328				seq_printf(sf, " %u",
329					   pin->error_inj_args[i][arg_idx]);
330			seq_puts(sf, "\n");
331		}
332	}
333
334	if (pin->tx_ignore_nack_until_eom)
335		seq_puts(sf, "tx-ignore-nack-until-eom\n");
336	if (pin->tx_custom_pulse)
337		seq_puts(sf, "tx-custom-pulse\n");
338	if (pin->tx_custom_low_usecs != CEC_TIM_CUSTOM_DEFAULT)
339		seq_printf(sf, "tx-custom-low-usecs %u\n",
340			   pin->tx_custom_low_usecs);
341	if (pin->tx_custom_high_usecs != CEC_TIM_CUSTOM_DEFAULT)
342		seq_printf(sf, "tx-custom-high-usecs %u\n",
343			   pin->tx_custom_high_usecs);
344	return 0;
345}
346