1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2011
4 * NVIDIA Corporation <www.nvidia.com>
5 */
6
7 #include <common.h>
8 #include <dm.h>
9 #include <fdtdec.h>
10 #include <input.h>
11 #include <keyboard.h>
12 #include <key_matrix.h>
13 #include <log.h>
14 #include <stdio_dev.h>
15 #include <tegra-kbc.h>
16 #include <asm/io.h>
17 #include <asm/arch/clock.h>
18 #include <asm/arch/funcmux.h>
19 #include <asm/arch-tegra/timer.h>
20 #include <linux/delay.h>
21 #include <linux/input.h>
22
23 enum {
24 KBC_MAX_GPIO = 24,
25 KBC_MAX_KPENT = 8, /* size of keypress entry queue */
26 };
27
28 #define KBC_FIFO_TH_CNT_SHIFT 14
29 #define KBC_DEBOUNCE_CNT_SHIFT 4
30 #define KBC_CONTROL_FIFO_CNT_INT_EN (1 << 3)
31 #define KBC_CONTROL_KBC_EN (1 << 0)
32 #define KBC_INT_FIFO_CNT_INT_STATUS (1 << 2)
33 #define KBC_KPENT_VALID (1 << 7)
34 #define KBC_ST_STATUS (1 << 3)
35
36 enum {
37 KBC_DEBOUNCE_COUNT = 2,
38 KBC_REPEAT_RATE_MS = 30,
39 KBC_REPEAT_DELAY_MS = 240,
40 KBC_CLOCK_KHZ = 32, /* Keyboard uses a 32KHz clock */
41 };
42
43 /* keyboard controller config and state */
44 struct tegra_kbd_priv {
45 struct input_config *input; /* The input layer */
46 struct key_matrix matrix; /* The key matrix layer */
47
48 struct kbc_tegra *kbc; /* tegra keyboard controller */
49 unsigned char inited; /* 1 if keyboard has been inited */
50 unsigned char first_scan; /* 1 if this is our first key scan */
51
52 /*
53 * After init we must wait a short time before polling the keyboard.
54 * This gives the tegra keyboard controller time to react after reset
55 * and lets us grab keys pressed during reset.
56 */
57 unsigned int init_dly_ms; /* Delay before we can read keyboard */
58 unsigned int start_time_ms; /* Time that we inited (in ms) */
59 unsigned int last_poll_ms; /* Time we should last polled */
60 unsigned int next_repeat_ms; /* Next time we repeat a key */
61 };
62
63 /**
64 * reads the keyboard fifo for current keypresses
65 *
66 * @param priv Keyboard private data
67 * @param fifo Place to put fifo results
68 * @param max_keycodes Maximum number of key codes to put in the fifo
69 * @return number of items put into fifo
70 */
tegra_kbc_find_keys(struct tegra_kbd_priv * priv,int * fifo,int max_keycodes)71 static int tegra_kbc_find_keys(struct tegra_kbd_priv *priv, int *fifo,
72 int max_keycodes)
73 {
74 struct key_matrix_key keys[KBC_MAX_KPENT], *key;
75 u32 kp_ent = 0;
76 int i;
77
78 for (key = keys, i = 0; i < KBC_MAX_KPENT; i++, key++) {
79 /* Get next word */
80 if (!(i & 3))
81 kp_ent = readl(&priv->kbc->kp_ent[i / 4]);
82
83 key->valid = (kp_ent & KBC_KPENT_VALID) != 0;
84 key->row = (kp_ent >> 3) & 0xf;
85 key->col = kp_ent & 0x7;
86
87 /* Shift to get next entry */
88 kp_ent >>= 8;
89 }
90 return key_matrix_decode(&priv->matrix, keys, KBC_MAX_KPENT, fifo,
91 max_keycodes);
92 }
93
94 /**
95 * Process all the keypress sequences in fifo and send key codes
96 *
97 * The fifo contains zero or more keypress sets. Each set
98 * consists of from 1-8 keycodes, representing the keycodes which
99 * were simultaneously pressed during that scan.
100 *
101 * This function works through each set and generates ASCII characters
102 * for each. Not that one set may produce more than one ASCII characters -
103 * for example holding down 'd' and 'f' at the same time will generate
104 * two ASCII characters.
105 *
106 * Note: if fifo_cnt is 0, we will tell the input layer that no keys are
107 * pressed.
108 *
109 * @param priv Keyboard private data
110 * @param fifo_cnt Number of entries in the keyboard fifo
111 */
process_fifo(struct tegra_kbd_priv * priv,int fifo_cnt)112 static void process_fifo(struct tegra_kbd_priv *priv, int fifo_cnt)
113 {
114 int fifo[KBC_MAX_KPENT];
115 int cnt = 0;
116
117 /* Always call input_send_keycodes() at least once */
118 do {
119 if (fifo_cnt)
120 cnt = tegra_kbc_find_keys(priv, fifo, KBC_MAX_KPENT);
121
122 input_send_keycodes(priv->input, fifo, cnt);
123 } while (--fifo_cnt > 0);
124 }
125
126 /**
127 * Check the keyboard controller and emit ASCII characters for any keys that
128 * are pressed.
129 *
130 * @param priv Keyboard private data
131 */
check_for_keys(struct tegra_kbd_priv * priv)132 static void check_for_keys(struct tegra_kbd_priv *priv)
133 {
134 int fifo_cnt;
135
136 if (!priv->first_scan &&
137 get_timer(priv->last_poll_ms) < KBC_REPEAT_RATE_MS)
138 return;
139 priv->last_poll_ms = get_timer(0);
140 priv->first_scan = 0;
141
142 /*
143 * Once we get here we know the keyboard has been scanned. So if there
144 * scan waiting for us, we know that nothing is held down.
145 */
146 fifo_cnt = (readl(&priv->kbc->interrupt) >> 4) & 0xf;
147 process_fifo(priv, fifo_cnt);
148 }
149
150 /**
151 * In order to detect keys pressed on boot, wait for the hardware to
152 * complete scanning the keys. This includes time to transition from
153 * Wkup mode to Continous polling mode and the repoll time. We can
154 * deduct the time that's already elapsed.
155 *
156 * @param priv Keyboard private data
157 */
kbd_wait_for_fifo_init(struct tegra_kbd_priv * priv)158 static void kbd_wait_for_fifo_init(struct tegra_kbd_priv *priv)
159 {
160 if (!priv->inited) {
161 unsigned long elapsed_time;
162 long delay_ms;
163
164 elapsed_time = get_timer(priv->start_time_ms);
165 delay_ms = priv->init_dly_ms - elapsed_time;
166 if (delay_ms > 0) {
167 udelay(delay_ms * 1000);
168 debug("%s: delay %ldms\n", __func__, delay_ms);
169 }
170
171 priv->inited = 1;
172 }
173 }
174
175 /**
176 * Check the tegra keyboard, and send any keys that are pressed.
177 *
178 * This is called by input_tstc() and input_getc() when they need more
179 * characters
180 *
181 * @param input Input configuration
182 * @return 1, to indicate that we have something to look at
183 */
tegra_kbc_check(struct input_config * input)184 static int tegra_kbc_check(struct input_config *input)
185 {
186 struct tegra_kbd_priv *priv = dev_get_priv(input->dev);
187
188 kbd_wait_for_fifo_init(priv);
189 check_for_keys(priv);
190
191 return 1;
192 }
193
194 /* configures keyboard GPIO registers to use the rows and columns */
config_kbc_gpio(struct tegra_kbd_priv * priv,struct kbc_tegra * kbc)195 static void config_kbc_gpio(struct tegra_kbd_priv *priv, struct kbc_tegra *kbc)
196 {
197 int i;
198
199 for (i = 0; i < KBC_MAX_GPIO; i++) {
200 u32 row_cfg, col_cfg;
201 u32 r_shift = 5 * (i % 6);
202 u32 c_shift = 4 * (i % 8);
203 u32 r_mask = 0x1f << r_shift;
204 u32 c_mask = 0xf << c_shift;
205 u32 r_offs = i / 6;
206 u32 c_offs = i / 8;
207
208 row_cfg = readl(&kbc->row_cfg[r_offs]);
209 col_cfg = readl(&kbc->col_cfg[c_offs]);
210
211 row_cfg &= ~r_mask;
212 col_cfg &= ~c_mask;
213
214 if (i < priv->matrix.num_rows) {
215 row_cfg |= ((i << 1) | 1) << r_shift;
216 } else {
217 col_cfg |= (((i - priv->matrix.num_rows) << 1) | 1)
218 << c_shift;
219 }
220
221 writel(row_cfg, &kbc->row_cfg[r_offs]);
222 writel(col_cfg, &kbc->col_cfg[c_offs]);
223 }
224 }
225
226 /**
227 * Start up the keyboard device
228 */
tegra_kbc_open(struct tegra_kbd_priv * priv)229 static void tegra_kbc_open(struct tegra_kbd_priv *priv)
230 {
231 struct kbc_tegra *kbc = priv->kbc;
232 unsigned int scan_period;
233 u32 val;
234
235 /*
236 * We will scan at twice the keyboard repeat rate, so that there is
237 * always a scan ready when we check it in check_for_keys().
238 */
239 scan_period = KBC_REPEAT_RATE_MS / 2;
240 writel(scan_period * KBC_CLOCK_KHZ, &kbc->rpt_dly);
241 writel(scan_period * KBC_CLOCK_KHZ, &kbc->init_dly);
242 /*
243 * Before reading from the keyboard we must wait for the init_dly
244 * plus the rpt_delay, plus 2ms for the row scan time.
245 */
246 priv->init_dly_ms = scan_period * 2 + 2;
247
248 val = KBC_DEBOUNCE_COUNT << KBC_DEBOUNCE_CNT_SHIFT;
249 val |= 1 << KBC_FIFO_TH_CNT_SHIFT; /* fifo interrupt threshold */
250 val |= KBC_CONTROL_KBC_EN; /* enable */
251 writel(val, &kbc->control);
252
253 priv->start_time_ms = get_timer(0);
254 priv->last_poll_ms = get_timer(0);
255 priv->next_repeat_ms = priv->last_poll_ms;
256 priv->first_scan = 1;
257 }
258
tegra_kbd_start(struct udevice * dev)259 static int tegra_kbd_start(struct udevice *dev)
260 {
261 struct tegra_kbd_priv *priv = dev_get_priv(dev);
262
263 /* Set up pin mux and enable the clock */
264 funcmux_select(PERIPH_ID_KBC, FUNCMUX_DEFAULT);
265 clock_enable(PERIPH_ID_KBC);
266 config_kbc_gpio(priv, priv->kbc);
267
268 tegra_kbc_open(priv);
269 debug("%s: Tegra keyboard ready\n", __func__);
270
271 return 0;
272 }
273
274 /**
275 * Set up the tegra keyboard. This is called by the stdio device handler
276 *
277 * We want to do this init when the keyboard is actually used rather than
278 * at start-up, since keyboard input may not currently be selected.
279 *
280 * Once the keyboard starts there will be a period during which we must
281 * wait for the keyboard to init. We do this only when a key is first
282 * read - see kbd_wait_for_fifo_init().
283 *
284 * @return 0 if ok, -ve on error
285 */
tegra_kbd_probe(struct udevice * dev)286 static int tegra_kbd_probe(struct udevice *dev)
287 {
288 struct tegra_kbd_priv *priv = dev_get_priv(dev);
289 struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev);
290 struct stdio_dev *sdev = &uc_priv->sdev;
291 struct input_config *input = &uc_priv->input;
292 int ret;
293
294 priv->kbc = dev_read_addr_ptr(dev);
295 if ((fdt_addr_t)priv->kbc == FDT_ADDR_T_NONE) {
296 debug("%s: No keyboard register found\n", __func__);
297 return -EINVAL;
298 }
299 input_set_delays(input, KBC_REPEAT_DELAY_MS, KBC_REPEAT_RATE_MS);
300
301 /* Decode the keyboard matrix information (16 rows, 8 columns) */
302 ret = key_matrix_init(&priv->matrix, 16, 8, 1);
303 if (ret) {
304 debug("%s: Could not init key matrix: %d\n", __func__, ret);
305 return ret;
306 }
307 ret = key_matrix_decode_fdt(dev, &priv->matrix);
308 if (ret) {
309 debug("%s: Could not decode key matrix from fdt: %d\n",
310 __func__, ret);
311 return ret;
312 }
313 input_add_tables(input, false);
314 if (priv->matrix.fn_keycode) {
315 ret = input_add_table(input, KEY_FN, -1,
316 priv->matrix.fn_keycode,
317 priv->matrix.key_count);
318 if (ret) {
319 debug("%s: input_add_table() failed\n", __func__);
320 return ret;
321 }
322 }
323
324 /* Register the device. init_tegra_keyboard() will be called soon */
325 priv->input = input;
326 input->dev = dev;
327 input->read_keys = tegra_kbc_check;
328 strcpy(sdev->name, "tegra-kbc");
329 ret = input_stdio_register(sdev);
330 if (ret) {
331 debug("%s: input_stdio_register() failed\n", __func__);
332 return ret;
333 }
334
335 return 0;
336 }
337
338 static const struct keyboard_ops tegra_kbd_ops = {
339 .start = tegra_kbd_start,
340 };
341
342 static const struct udevice_id tegra_kbd_ids[] = {
343 { .compatible = "nvidia,tegra20-kbc" },
344 { }
345 };
346
347 U_BOOT_DRIVER(tegra_kbd) = {
348 .name = "tegra_kbd",
349 .id = UCLASS_KEYBOARD,
350 .of_match = tegra_kbd_ids,
351 .probe = tegra_kbd_probe,
352 .ops = &tegra_kbd_ops,
353 .priv_auto = sizeof(struct tegra_kbd_priv),
354 };
355