xref: /openbmc/u-boot/drivers/input/i8042.c (revision 70eb8253)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2002 ELTEC Elektronik AG
4  * Frank Gottschling <fgottschling@eltec.de>
5  */
6 
7 /* i8042.c - Intel 8042 keyboard driver routines */
8 
9 #include <common.h>
10 #include <dm.h>
11 #include <errno.h>
12 #include <i8042.h>
13 #include <input.h>
14 #include <keyboard.h>
15 #include <asm/io.h>
16 
17 DECLARE_GLOBAL_DATA_PTR;
18 
19 /* defines */
20 #define in8(p)		inb(p)
21 #define out8(p, v)	outb(v, p)
22 
23 enum {
24 	QUIRK_DUP_POR	= 1 << 0,
25 };
26 
27 /* locals */
28 struct i8042_kbd_priv {
29 	bool extended;	/* true if an extended keycode is expected next */
30 	int quirks;	/* quirks that we support */
31 };
32 
33 static unsigned char ext_key_map[] = {
34 	0x1c, /* keypad enter */
35 	0x1d, /* right control */
36 	0x35, /* keypad slash */
37 	0x37, /* print screen */
38 	0x38, /* right alt */
39 	0x46, /* break */
40 	0x47, /* editpad home */
41 	0x48, /* editpad up */
42 	0x49, /* editpad pgup */
43 	0x4b, /* editpad left */
44 	0x4d, /* editpad right */
45 	0x4f, /* editpad end */
46 	0x50, /* editpad dn */
47 	0x51, /* editpad pgdn */
48 	0x52, /* editpad ins */
49 	0x53, /* editpad del */
50 	0x00  /* map end */
51 	};
52 
53 static int kbd_input_empty(void)
54 {
55 	int kbd_timeout = KBD_TIMEOUT * 1000;
56 
57 	while ((in8(I8042_STS_REG) & STATUS_IBF) && kbd_timeout--)
58 		udelay(1);
59 
60 	return kbd_timeout != -1;
61 }
62 
63 static int kbd_output_full(void)
64 {
65 	int kbd_timeout = KBD_TIMEOUT * 1000;
66 
67 	while (((in8(I8042_STS_REG) & STATUS_OBF) == 0) && kbd_timeout--)
68 		udelay(1);
69 
70 	return kbd_timeout != -1;
71 }
72 
73 /**
74  * check_leds() - Check the keyboard LEDs and update them it needed
75  *
76  * @ret:	Value to return
77  * @return value of @ret
78  */
79 static int i8042_kbd_update_leds(struct udevice *dev, int leds)
80 {
81 	kbd_input_empty();
82 	out8(I8042_DATA_REG, CMD_SET_KBD_LED);
83 	kbd_input_empty();
84 	out8(I8042_DATA_REG, leds & 0x7);
85 
86 	return 0;
87 }
88 
89 static int kbd_write(int reg, int value)
90 {
91 	if (!kbd_input_empty())
92 		return -1;
93 	out8(reg, value);
94 
95 	return 0;
96 }
97 
98 static int kbd_read(int reg)
99 {
100 	if (!kbd_output_full())
101 		return -1;
102 
103 	return in8(reg);
104 }
105 
106 static int kbd_cmd_read(int cmd)
107 {
108 	if (kbd_write(I8042_CMD_REG, cmd))
109 		return -1;
110 
111 	return kbd_read(I8042_DATA_REG);
112 }
113 
114 static int kbd_cmd_write(int cmd, int data)
115 {
116 	if (kbd_write(I8042_CMD_REG, cmd))
117 		return -1;
118 
119 	return kbd_write(I8042_DATA_REG, data);
120 }
121 
122 static int kbd_reset(int quirk)
123 {
124 	int config;
125 
126 	/* controller self test */
127 	if (kbd_cmd_read(CMD_SELF_TEST) != KBC_TEST_OK)
128 		goto err;
129 
130 	/* keyboard reset */
131 	if (kbd_write(I8042_DATA_REG, CMD_RESET_KBD) ||
132 	    kbd_read(I8042_DATA_REG) != KBD_ACK ||
133 	    kbd_read(I8042_DATA_REG) != KBD_POR)
134 		goto err;
135 
136 	if (kbd_write(I8042_DATA_REG, CMD_DRAIN_OUTPUT) ||
137 	    kbd_read(I8042_DATA_REG) != KBD_ACK)
138 		goto err;
139 
140 	/* set AT translation and disable irq */
141 	config = kbd_cmd_read(CMD_RD_CONFIG);
142 	if (config == -1)
143 		goto err;
144 
145 	/* Sometimes get a second byte */
146 	else if ((quirk & QUIRK_DUP_POR) && config == KBD_POR)
147 		config = kbd_cmd_read(CMD_RD_CONFIG);
148 
149 	config |= CONFIG_AT_TRANS;
150 	config &= ~(CONFIG_KIRQ_EN | CONFIG_MIRQ_EN);
151 	if (kbd_cmd_write(CMD_WR_CONFIG, config))
152 		goto err;
153 
154 	/* enable keyboard */
155 	if (kbd_write(I8042_CMD_REG, CMD_KBD_EN) ||
156 	    !kbd_input_empty())
157 		goto err;
158 
159 	return 0;
160 err:
161 	debug("%s: Keyboard failure\n", __func__);
162 	return -1;
163 }
164 
165 static int kbd_controller_present(void)
166 {
167 	return in8(I8042_STS_REG) != 0xff;
168 }
169 
170 /** Flush all buffer from keyboard controller to host*/
171 static void i8042_flush(void)
172 {
173 	int timeout;
174 
175 	/*
176 	 * The delay is to give the keyboard controller some time
177 	 * to fill the next byte.
178 	 */
179 	while (1) {
180 		timeout = 100;	/* wait for no longer than 100us */
181 		while (timeout > 0 && !(in8(I8042_STS_REG) & STATUS_OBF)) {
182 			udelay(1);
183 			timeout--;
184 		}
185 
186 		/* Try to pull next byte if not timeout */
187 		if (in8(I8042_STS_REG) & STATUS_OBF)
188 			in8(I8042_DATA_REG);
189 		else
190 			break;
191 	}
192 }
193 
194 /**
195  * Disables the keyboard so that key strokes no longer generate scancodes to
196  * the host.
197  *
198  * @return 0 if ok, -1 if keyboard input was found while disabling
199  */
200 static int i8042_disable(void)
201 {
202 	if (kbd_input_empty() == 0)
203 		return -1;
204 
205 	/* Disable keyboard */
206 	out8(I8042_CMD_REG, CMD_KBD_DIS);
207 
208 	if (kbd_input_empty() == 0)
209 		return -1;
210 
211 	return 0;
212 }
213 
214 static int i8042_kbd_check(struct input_config *input)
215 {
216 	struct i8042_kbd_priv *priv = dev_get_priv(input->dev);
217 
218 	if ((in8(I8042_STS_REG) & STATUS_OBF) == 0) {
219 		return 0;
220 	} else {
221 		bool release = false;
222 		int scan_code;
223 		int i;
224 
225 		scan_code = in8(I8042_DATA_REG);
226 		if (scan_code == 0xfa) {
227 			return 0;
228 		} else if (scan_code == 0xe0) {
229 			priv->extended = true;
230 			return 0;
231 		}
232 		if (scan_code & 0x80) {
233 			scan_code &= 0x7f;
234 			release = true;
235 		}
236 		if (priv->extended) {
237 			priv->extended = false;
238 			for (i = 0; ext_key_map[i]; i++) {
239 				if (ext_key_map[i] == scan_code) {
240 					scan_code = 0x60 + i;
241 					break;
242 				}
243 			}
244 			/* not found ? */
245 			if (!ext_key_map[i])
246 				return 0;
247 		}
248 
249 		input_add_keycode(input, scan_code, release);
250 		return 1;
251 	}
252 }
253 
254 /* i8042_kbd_init - reset keyboard and init state flags */
255 static int i8042_start(struct udevice *dev)
256 {
257 	struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev);
258 	struct i8042_kbd_priv *priv = dev_get_priv(dev);
259 	struct input_config *input = &uc_priv->input;
260 	int keymap, try;
261 	char *penv;
262 	int ret;
263 
264 	if (!kbd_controller_present()) {
265 		debug("i8042 keyboard controller is not present\n");
266 		return -ENOENT;
267 	}
268 
269 	/* Init keyboard device (default US layout) */
270 	keymap = KBD_US;
271 	penv = env_get("keymap");
272 	if (penv != NULL) {
273 		if (strncmp(penv, "de", 3) == 0)
274 			keymap = KBD_GER;
275 	}
276 
277 	for (try = 0; kbd_reset(priv->quirks) != 0; try++) {
278 		if (try >= KBD_RESET_TRIES)
279 			return -1;
280 	}
281 
282 	ret = input_add_tables(input, keymap == KBD_GER);
283 	if (ret)
284 		return ret;
285 
286 	i8042_kbd_update_leds(dev, NORMAL);
287 	debug("%s: started\n", __func__);
288 
289 	return 0;
290 }
291 
292 static int i8042_kbd_remove(struct udevice *dev)
293 {
294 	if (i8042_disable())
295 		log_debug("i8042_disable() failed. fine, continue.\n");
296 	i8042_flush();
297 
298 	return 0;
299 }
300 
301 /**
302  * Set up the i8042 keyboard. This is called by the stdio device handler
303  *
304  * We want to do this init when the keyboard is actually used rather than
305  * at start-up, since keyboard input may not currently be selected.
306  *
307  * Once the keyboard starts there will be a period during which we must
308  * wait for the keyboard to init. We do this only when a key is first
309  * read - see kbd_wait_for_fifo_init().
310  *
311  * @return 0 if ok, -ve on error
312  */
313 static int i8042_kbd_probe(struct udevice *dev)
314 {
315 	struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev);
316 	struct i8042_kbd_priv *priv = dev_get_priv(dev);
317 	struct stdio_dev *sdev = &uc_priv->sdev;
318 	struct input_config *input = &uc_priv->input;
319 	int ret;
320 
321 	if (fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
322 			    "intel,duplicate-por"))
323 		priv->quirks |= QUIRK_DUP_POR;
324 
325 	/* Register the device. i8042_start() will be called soon */
326 	input->dev = dev;
327 	input->read_keys = i8042_kbd_check;
328 	input_allow_repeats(input, true);
329 	strcpy(sdev->name, "i8042-kbd");
330 	ret = input_stdio_register(sdev);
331 	if (ret) {
332 		debug("%s: input_stdio_register() failed\n", __func__);
333 		return ret;
334 	}
335 	debug("%s: ready\n", __func__);
336 
337 	return 0;
338 }
339 
340 static const struct keyboard_ops i8042_kbd_ops = {
341 	.start	= i8042_start,
342 	.update_leds	= i8042_kbd_update_leds,
343 };
344 
345 static const struct udevice_id i8042_kbd_ids[] = {
346 	{ .compatible = "intel,i8042-keyboard" },
347 	{ }
348 };
349 
350 U_BOOT_DRIVER(i8042_kbd) = {
351 	.name	= "i8042_kbd",
352 	.id	= UCLASS_KEYBOARD,
353 	.of_match = i8042_kbd_ids,
354 	.probe = i8042_kbd_probe,
355 	.remove = i8042_kbd_remove,
356 	.ops	= &i8042_kbd_ops,
357 	.priv_auto_alloc_size = sizeof(struct i8042_kbd_priv),
358 };
359