xref: /openbmc/u-boot/drivers/input/i8042.c (revision baefb63a)
1 /*
2  * (C) Copyright 2002 ELTEC Elektronik AG
3  * Frank Gottschling <fgottschling@eltec.de>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 /* i8042.c - Intel 8042 keyboard driver routines */
9 
10 #include <common.h>
11 #include <dm.h>
12 #include <errno.h>
13 #include <i8042.h>
14 #include <input.h>
15 #include <keyboard.h>
16 #include <asm/io.h>
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 /* defines */
21 #define in8(p)		inb(p)
22 #define out8(p, v)	outb(v, p)
23 
24 enum {
25 	QUIRK_DUP_POR	= 1 << 0,
26 };
27 
28 /* locals */
29 struct i8042_kbd_priv {
30 	bool extended;	/* true if an extended keycode is expected next */
31 	int quirks;	/* quirks that we support */
32 };
33 
34 static unsigned char ext_key_map[] = {
35 	0x1c, /* keypad enter */
36 	0x1d, /* right control */
37 	0x35, /* keypad slash */
38 	0x37, /* print screen */
39 	0x38, /* right alt */
40 	0x46, /* break */
41 	0x47, /* editpad home */
42 	0x48, /* editpad up */
43 	0x49, /* editpad pgup */
44 	0x4b, /* editpad left */
45 	0x4d, /* editpad right */
46 	0x4f, /* editpad end */
47 	0x50, /* editpad dn */
48 	0x51, /* editpad pgdn */
49 	0x52, /* editpad ins */
50 	0x53, /* editpad del */
51 	0x00  /* map end */
52 	};
53 
54 static int kbd_input_empty(void)
55 {
56 	int kbd_timeout = KBD_TIMEOUT * 1000;
57 
58 	while ((in8(I8042_STS_REG) & STATUS_IBF) && kbd_timeout--)
59 		udelay(1);
60 
61 	return kbd_timeout != -1;
62 }
63 
64 static int kbd_output_full(void)
65 {
66 	int kbd_timeout = KBD_TIMEOUT * 1000;
67 
68 	while (((in8(I8042_STS_REG) & STATUS_OBF) == 0) && kbd_timeout--)
69 		udelay(1);
70 
71 	return kbd_timeout != -1;
72 }
73 
74 /**
75  * check_leds() - Check the keyboard LEDs and update them it needed
76  *
77  * @ret:	Value to return
78  * @return value of @ret
79  */
80 static int i8042_kbd_update_leds(struct udevice *dev, int leds)
81 {
82 	kbd_input_empty();
83 	out8(I8042_DATA_REG, CMD_SET_KBD_LED);
84 	kbd_input_empty();
85 	out8(I8042_DATA_REG, leds & 0x7);
86 
87 	return 0;
88 }
89 
90 static int kbd_write(int reg, int value)
91 {
92 	if (!kbd_input_empty())
93 		return -1;
94 	out8(reg, value);
95 
96 	return 0;
97 }
98 
99 static int kbd_read(int reg)
100 {
101 	if (!kbd_output_full())
102 		return -1;
103 
104 	return in8(reg);
105 }
106 
107 static int kbd_cmd_read(int cmd)
108 {
109 	if (kbd_write(I8042_CMD_REG, cmd))
110 		return -1;
111 
112 	return kbd_read(I8042_DATA_REG);
113 }
114 
115 static int kbd_cmd_write(int cmd, int data)
116 {
117 	if (kbd_write(I8042_CMD_REG, cmd))
118 		return -1;
119 
120 	return kbd_write(I8042_DATA_REG, data);
121 }
122 
123 static int kbd_reset(int quirk)
124 {
125 	int config;
126 
127 	/* controller self test */
128 	if (kbd_cmd_read(CMD_SELF_TEST) != KBC_TEST_OK)
129 		goto err;
130 
131 	/* keyboard reset */
132 	if (kbd_write(I8042_DATA_REG, CMD_RESET_KBD) ||
133 	    kbd_read(I8042_DATA_REG) != KBD_ACK ||
134 	    kbd_read(I8042_DATA_REG) != KBD_POR)
135 		goto err;
136 
137 	if (kbd_write(I8042_DATA_REG, CMD_DRAIN_OUTPUT) ||
138 	    kbd_read(I8042_DATA_REG) != KBD_ACK)
139 		goto err;
140 
141 	/* set AT translation and disable irq */
142 	config = kbd_cmd_read(CMD_RD_CONFIG);
143 	if (config == -1)
144 		goto err;
145 
146 	/* Sometimes get a second byte */
147 	else if ((quirk & QUIRK_DUP_POR) && config == KBD_POR)
148 		config = kbd_cmd_read(CMD_RD_CONFIG);
149 
150 	config |= CONFIG_AT_TRANS;
151 	config &= ~(CONFIG_KIRQ_EN | CONFIG_MIRQ_EN);
152 	if (kbd_cmd_write(CMD_WR_CONFIG, config))
153 		goto err;
154 
155 	/* enable keyboard */
156 	if (kbd_write(I8042_CMD_REG, CMD_KBD_EN) ||
157 	    !kbd_input_empty())
158 		goto err;
159 
160 	return 0;
161 err:
162 	debug("%s: Keyboard failure\n", __func__);
163 	return -1;
164 }
165 
166 static int kbd_controller_present(void)
167 {
168 	return in8(I8042_STS_REG) != 0xff;
169 }
170 
171 /*
172  * Implement a weak default function for boards that optionally
173  * need to skip the i8042 initialization.
174  *
175  * TODO(sjg@chromium.org): Use device tree for this?
176  */
177 int __weak board_i8042_skip(void)
178 {
179 	/* As default, don't skip */
180 	return 0;
181 }
182 
183 void i8042_flush(void)
184 {
185 	int timeout;
186 
187 	/*
188 	 * The delay is to give the keyboard controller some time
189 	 * to fill the next byte.
190 	 */
191 	while (1) {
192 		timeout = 100;	/* wait for no longer than 100us */
193 		while (timeout > 0 && !(in8(I8042_STS_REG) & STATUS_OBF)) {
194 			udelay(1);
195 			timeout--;
196 		}
197 
198 		/* Try to pull next byte if not timeout */
199 		if (in8(I8042_STS_REG) & STATUS_OBF)
200 			in8(I8042_DATA_REG);
201 		else
202 			break;
203 	}
204 }
205 
206 int i8042_disable(void)
207 {
208 	if (kbd_input_empty() == 0)
209 		return -1;
210 
211 	/* Disable keyboard */
212 	out8(I8042_CMD_REG, CMD_KBD_DIS);
213 
214 	if (kbd_input_empty() == 0)
215 		return -1;
216 
217 	return 0;
218 }
219 
220 static int i8042_kbd_check(struct input_config *input)
221 {
222 	struct i8042_kbd_priv *priv = dev_get_priv(input->dev);
223 
224 	if ((in8(I8042_STS_REG) & STATUS_OBF) == 0) {
225 		return 0;
226 	} else {
227 		bool release = false;
228 		int scan_code;
229 		int i;
230 
231 		scan_code = in8(I8042_DATA_REG);
232 		if (scan_code == 0xfa) {
233 			return 0;
234 		} else if (scan_code == 0xe0) {
235 			priv->extended = true;
236 			return 0;
237 		}
238 		if (scan_code & 0x80) {
239 			scan_code &= 0x7f;
240 			release = true;
241 		}
242 		if (priv->extended) {
243 			priv->extended = false;
244 			for (i = 0; ext_key_map[i]; i++) {
245 				if (ext_key_map[i] == scan_code) {
246 					scan_code = 0x60 + i;
247 					break;
248 				}
249 			}
250 			/* not found ? */
251 			if (!ext_key_map[i])
252 				return 0;
253 		}
254 
255 		input_add_keycode(input, scan_code, release);
256 		return 1;
257 	}
258 }
259 
260 /* i8042_kbd_init - reset keyboard and init state flags */
261 static int i8042_start(struct udevice *dev)
262 {
263 	struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev);
264 	struct i8042_kbd_priv *priv = dev_get_priv(dev);
265 	struct input_config *input = &uc_priv->input;
266 	int keymap, try;
267 	char *penv;
268 	int ret;
269 
270 	if (!kbd_controller_present() || board_i8042_skip()) {
271 		debug("i8042 keyboard controller is not present\n");
272 		return -ENOENT;
273 	}
274 
275 	/* Init keyboard device (default US layout) */
276 	keymap = KBD_US;
277 	penv = env_get("keymap");
278 	if (penv != NULL) {
279 		if (strncmp(penv, "de", 3) == 0)
280 			keymap = KBD_GER;
281 	}
282 
283 	for (try = 0; kbd_reset(priv->quirks) != 0; try++) {
284 		if (try >= KBD_RESET_TRIES)
285 			return -1;
286 	}
287 
288 	ret = input_add_tables(input, keymap == KBD_GER);
289 	if (ret)
290 		return ret;
291 
292 	i8042_kbd_update_leds(dev, NORMAL);
293 	debug("%s: started\n", __func__);
294 
295 	return 0;
296 }
297 
298 /**
299  * Set up the i8042 keyboard. This is called by the stdio device handler
300  *
301  * We want to do this init when the keyboard is actually used rather than
302  * at start-up, since keyboard input may not currently be selected.
303  *
304  * Once the keyboard starts there will be a period during which we must
305  * wait for the keyboard to init. We do this only when a key is first
306  * read - see kbd_wait_for_fifo_init().
307  *
308  * @return 0 if ok, -ve on error
309  */
310 static int i8042_kbd_probe(struct udevice *dev)
311 {
312 	struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev);
313 	struct i8042_kbd_priv *priv = dev_get_priv(dev);
314 	struct stdio_dev *sdev = &uc_priv->sdev;
315 	struct input_config *input = &uc_priv->input;
316 	int ret;
317 
318 	if (fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
319 			    "intel,duplicate-por"))
320 		priv->quirks |= QUIRK_DUP_POR;
321 
322 	/* Register the device. i8042_start() will be called soon */
323 	input->dev = dev;
324 	input->read_keys = i8042_kbd_check;
325 	input_allow_repeats(input, true);
326 	strcpy(sdev->name, "i8042-kbd");
327 	ret = input_stdio_register(sdev);
328 	if (ret) {
329 		debug("%s: input_stdio_register() failed\n", __func__);
330 		return ret;
331 	}
332 	debug("%s: ready\n", __func__);
333 
334 	return 0;
335 }
336 
337 static const struct keyboard_ops i8042_kbd_ops = {
338 	.start	= i8042_start,
339 	.update_leds	= i8042_kbd_update_leds,
340 };
341 
342 static const struct udevice_id i8042_kbd_ids[] = {
343 	{ .compatible = "intel,i8042-keyboard" },
344 	{ }
345 };
346 
347 U_BOOT_DRIVER(i8042_kbd) = {
348 	.name	= "i8042_kbd",
349 	.id	= UCLASS_KEYBOARD,
350 	.of_match = i8042_kbd_ids,
351 	.probe = i8042_kbd_probe,
352 	.ops	= &i8042_kbd_ops,
353 	.priv_auto_alloc_size = sizeof(struct i8042_kbd_priv),
354 };
355