blob: f164791bee6128fcf0b3bce5ec55cfb1db916ee6 [file] [log] [blame]
Rakesh Iyer6642a682012-04-17 09:01:35 +00001/*
2 * (C) Copyright 2011
3 * NVIDIA Corporation <www.nvidia.com>
4 *
5 * See file CREDITS for list of people who contributed to this
6 * project.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21 * MA 02111-1307 USA
22 */
23
24#include <common.h>
25#include <fdtdec.h>
26#include <input.h>
27#include <key_matrix.h>
28#include <stdio_dev.h>
29#include <tegra-kbc.h>
30#include <asm/io.h>
31#include <asm/arch/clock.h>
32#include <asm/arch/funcmux.h>
33#include <asm/arch/timer.h>
34#include <linux/input.h>
35
36DECLARE_GLOBAL_DATA_PTR;
37
38enum {
39 KBC_MAX_GPIO = 24,
40 KBC_MAX_KPENT = 8, /* size of keypress entry queue */
41};
42
43#define KBC_FIFO_TH_CNT_SHIFT 14
44#define KBC_DEBOUNCE_CNT_SHIFT 4
45#define KBC_CONTROL_FIFO_CNT_INT_EN (1 << 3)
46#define KBC_CONTROL_KBC_EN (1 << 0)
47#define KBC_INT_FIFO_CNT_INT_STATUS (1 << 2)
48#define KBC_KPENT_VALID (1 << 7)
49#define KBC_ST_STATUS (1 << 3)
50
51enum {
52 KBC_DEBOUNCE_COUNT = 2,
53 KBC_REPEAT_RATE_MS = 30,
54 KBC_REPEAT_DELAY_MS = 240,
55 KBC_CLOCK_KHZ = 32, /* Keyboard uses a 32KHz clock */
56};
57
58/* keyboard controller config and state */
59static struct keyb {
60 struct input_config input; /* The input layer */
61 struct key_matrix matrix; /* The key matrix layer */
62
63 struct kbc_tegra *kbc; /* tegra keyboard controller */
64 unsigned char inited; /* 1 if keyboard has been inited */
65 unsigned char first_scan; /* 1 if this is our first key scan */
66
67 /*
68 * After init we must wait a short time before polling the keyboard.
69 * This gives the tegra keyboard controller time to react after reset
70 * and lets us grab keys pressed during reset.
71 */
72 unsigned int init_dly_ms; /* Delay before we can read keyboard */
73 unsigned int start_time_ms; /* Time that we inited (in ms) */
74 unsigned int last_poll_ms; /* Time we should last polled */
75 unsigned int next_repeat_ms; /* Next time we repeat a key */
76} config;
77
78/**
79 * reads the keyboard fifo for current keypresses
80 *
81 * @param config Keyboard config
82 * @param fifo Place to put fifo results
83 * @param max_keycodes Maximum number of key codes to put in the fifo
84 * @return number of items put into fifo
85 */
86static int tegra_kbc_find_keys(struct keyb *config, int *fifo,
87 int max_keycodes)
88{
89 struct key_matrix_key keys[KBC_MAX_KPENT], *key;
90 u32 kp_ent = 0;
91 int i;
92
93 for (key = keys, i = 0; i < KBC_MAX_KPENT; i++, key++) {
94 /* Get next word */
95 if (!(i & 3))
96 kp_ent = readl(&config->kbc->kp_ent[i / 4]);
97
98 key->valid = (kp_ent & KBC_KPENT_VALID) != 0;
99 key->row = (kp_ent >> 3) & 0xf;
100 key->col = kp_ent & 0x7;
101
102 /* Shift to get next entry */
103 kp_ent >>= 8;
104 }
105 return key_matrix_decode(&config->matrix, keys, KBC_MAX_KPENT, fifo,
106 max_keycodes);
107}
108
109/**
110 * Process all the keypress sequences in fifo and send key codes
111 *
112 * The fifo contains zero or more keypress sets. Each set
113 * consists of from 1-8 keycodes, representing the keycodes which
114 * were simultaneously pressed during that scan.
115 *
116 * This function works through each set and generates ASCII characters
117 * for each. Not that one set may produce more than one ASCII characters -
118 * for example holding down 'd' and 'f' at the same time will generate
119 * two ASCII characters.
120 *
121 * Note: if fifo_cnt is 0, we will tell the input layer that no keys are
122 * pressed.
123 *
124 * @param config Keyboard config
125 * @param fifo_cnt Number of entries in the keyboard fifo
126 */
127static void process_fifo(struct keyb *config, int fifo_cnt)
128{
129 int fifo[KBC_MAX_KPENT];
130 int cnt = 0;
131
132 /* Always call input_send_keycodes() at least once */
133 do {
134 if (fifo_cnt)
135 cnt = tegra_kbc_find_keys(config, fifo, KBC_MAX_KPENT);
136
137 input_send_keycodes(&config->input, fifo, cnt);
138 } while (--fifo_cnt > 0);
139}
140
141/**
142 * Check the keyboard controller and emit ASCII characters for any keys that
143 * are pressed.
144 *
145 * @param config Keyboard config
146 */
147static void check_for_keys(struct keyb *config)
148{
149 int fifo_cnt;
150
151 if (!config->first_scan &&
152 get_timer(config->last_poll_ms) < KBC_REPEAT_RATE_MS)
153 return;
154 config->last_poll_ms = get_timer(0);
155 config->first_scan = 0;
156
157 /*
158 * Once we get here we know the keyboard has been scanned. So if there
159 * scan waiting for us, we know that nothing is held down.
160 */
161 fifo_cnt = (readl(&config->kbc->interrupt) >> 4) & 0xf;
162 process_fifo(config, fifo_cnt);
163}
164
165/**
166 * In order to detect keys pressed on boot, wait for the hardware to
167 * complete scanning the keys. This includes time to transition from
168 * Wkup mode to Continous polling mode and the repoll time. We can
169 * deduct the time that's already elapsed.
170 *
171 * @param config Keyboard config
172 */
173static void kbd_wait_for_fifo_init(struct keyb *config)
174{
175 if (!config->inited) {
176 unsigned long elapsed_time;
177 long delay_ms;
178
179 elapsed_time = get_timer(config->start_time_ms);
180 delay_ms = config->init_dly_ms - elapsed_time;
181 if (delay_ms > 0) {
182 udelay(delay_ms * 1000);
183 debug("%s: delay %ldms\n", __func__, delay_ms);
184 }
185
186 config->inited = 1;
187 }
188}
189
190/**
191 * Check the tegra keyboard, and send any keys that are pressed.
192 *
193 * This is called by input_tstc() and input_getc() when they need more
194 * characters
195 *
196 * @param input Input configuration
197 * @return 1, to indicate that we have something to look at
198 */
199int tegra_kbc_check(struct input_config *input)
200{
201 kbd_wait_for_fifo_init(&config);
202 check_for_keys(&config);
203
204 return 1;
205}
206
207/**
208 * Test if keys are available to be read
209 *
210 * @return 0 if no keys available, 1 if keys are available
211 */
212static int kbd_tstc(void)
213{
214 /* Just get input to do this for us */
215 return input_tstc(&config.input);
216}
217
218/**
219 * Read a key
220 *
221 * TODO: U-Boot wants 0 for no key, but Ctrl-@ is a valid key...
222 *
223 * @return ASCII key code, or 0 if no key, or -1 if error
224 */
225static int kbd_getc(void)
226{
227 /* Just get input to do this for us */
228 return input_getc(&config.input);
229}
230
231/* configures keyboard GPIO registers to use the rows and columns */
232static void config_kbc_gpio(struct kbc_tegra *kbc)
233{
234 int i;
235
236 for (i = 0; i < KBC_MAX_GPIO; i++) {
237 u32 row_cfg, col_cfg;
238 u32 r_shift = 5 * (i % 6);
239 u32 c_shift = 4 * (i % 8);
240 u32 r_mask = 0x1f << r_shift;
241 u32 c_mask = 0xf << c_shift;
242 u32 r_offs = i / 6;
243 u32 c_offs = i / 8;
244
245 row_cfg = readl(&kbc->row_cfg[r_offs]);
246 col_cfg = readl(&kbc->col_cfg[c_offs]);
247
248 row_cfg &= ~r_mask;
249 col_cfg &= ~c_mask;
250
251 if (i < config.matrix.num_rows) {
252 row_cfg |= ((i << 1) | 1) << r_shift;
253 } else {
254 col_cfg |= (((i - config.matrix.num_rows) << 1) | 1)
255 << c_shift;
256 }
257
258 writel(row_cfg, &kbc->row_cfg[r_offs]);
259 writel(col_cfg, &kbc->col_cfg[c_offs]);
260 }
261}
262
263/**
264 * Start up the keyboard device
265 */
266static void tegra_kbc_open(void)
267{
268 struct kbc_tegra *kbc = config.kbc;
269 unsigned int scan_period;
270 u32 val;
271
272 /*
273 * We will scan at twice the keyboard repeat rate, so that there is
274 * always a scan ready when we check it in check_for_keys().
275 */
276 scan_period = KBC_REPEAT_RATE_MS / 2;
277 writel(scan_period * KBC_CLOCK_KHZ, &kbc->rpt_dly);
278 writel(scan_period * KBC_CLOCK_KHZ, &kbc->init_dly);
279 /*
280 * Before reading from the keyboard we must wait for the init_dly
281 * plus the rpt_delay, plus 2ms for the row scan time.
282 */
283 config.init_dly_ms = scan_period * 2 + 2;
284
285 val = KBC_DEBOUNCE_COUNT << KBC_DEBOUNCE_CNT_SHIFT;
286 val |= 1 << KBC_FIFO_TH_CNT_SHIFT; /* fifo interrupt threshold */
287 val |= KBC_CONTROL_KBC_EN; /* enable */
288 writel(val, &kbc->control);
289
290 config.start_time_ms = get_timer(0);
291 config.last_poll_ms = config.next_repeat_ms = get_timer(0);
292 config.first_scan = 1;
293}
294
295/**
296 * Set up the tegra keyboard. This is called by the stdio device handler
297 *
298 * We want to do this init when the keyboard is actually used rather than
299 * at start-up, since keyboard input may not currently be selected.
300 *
301 * Once the keyboard starts there will be a period during which we must
302 * wait for the keyboard to init. We do this only when a key is first
303 * read - see kbd_wait_for_fifo_init().
304 *
305 * @return 0 if ok, -ve on error
306 */
307static int init_tegra_keyboard(void)
308{
309#ifdef CONFIG_OF_CONTROL
310 int node;
311
312 node = fdtdec_next_compatible(gd->fdt_blob, 0,
313 COMPAT_NVIDIA_TEGRA20_KBC);
314 if (node < 0) {
315 debug("%s: cannot locate keyboard node\n", __func__);
316 return node;
317 }
318 config.kbc = (struct kbc_tegra *)fdtdec_get_addr(gd->fdt_blob,
319 node, "reg");
320 if ((fdt_addr_t)config.kbc == FDT_ADDR_T_NONE) {
321 debug("%s: No keyboard register found\n", __func__);
322 return -1;
323 }
324
325 /* Decode the keyboard matrix information (16 rows, 8 columns) */
326 if (key_matrix_init(&config.matrix, 16, 8)) {
327 debug("%s: Could not init key matrix\n", __func__);
328 return -1;
329 }
330 if (key_matrix_decode_fdt(&config.matrix, gd->fdt_blob, node)) {
331 debug("%s: Could not decode key matrix from fdt\n", __func__);
332 return -1;
333 }
334 if (config.matrix.fn_keycode) {
335 if (input_add_table(&config.input, KEY_FN, -1,
336 config.matrix.fn_keycode,
337 config.matrix.key_count))
338 return -1;
339 }
340#else
341#error "Tegra keyboard driver requires FDT definitions"
342#endif
343
344 /* Set up pin mux and enable the clock */
345 funcmux_select(PERIPH_ID_KBC, FUNCMUX_DEFAULT);
346 clock_enable(PERIPH_ID_KBC);
347 config_kbc_gpio(config.kbc);
348
349 tegra_kbc_open();
350 debug("%s: Tegra keyboard ready\n", __func__);
351
352 return 0;
353}
354
355int drv_keyboard_init(void)
356{
357 struct stdio_dev dev;
358
359 if (input_init(&config.input, 0, KBC_REPEAT_DELAY_MS,
360 KBC_REPEAT_RATE_MS)) {
361 debug("%s: Cannot set up input\n", __func__);
362 return -1;
363 }
364 config.input.read_keys = tegra_kbc_check;
365
366 memset(&dev, '\0', sizeof(dev));
367 strcpy(dev.name, "tegra-kbc");
368 dev.flags = DEV_FLAGS_INPUT | DEV_FLAGS_SYSTEM;
369 dev.getc = kbd_getc;
370 dev.tstc = kbd_tstc;
371 dev.start = init_tegra_keyboard;
372
373 /* Register the device. init_tegra_keyboard() will be called soon */
374 return input_stdio_register(&dev);
375}