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Rakesh Iyer6642a682012-04-17 09:01:35 +00001/*
2 * (C) Copyright 2011
3 * NVIDIA Corporation <www.nvidia.com>
4 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02005 * SPDX-License-Identifier: GPL-2.0+
Rakesh Iyer6642a682012-04-17 09:01:35 +00006 */
7
8#include <common.h>
Simon Glassf77f5e92015-10-18 21:17:16 -06009#include <dm.h>
Rakesh Iyer6642a682012-04-17 09:01:35 +000010#include <fdtdec.h>
11#include <input.h>
Simon Glassf77f5e92015-10-18 21:17:16 -060012#include <keyboard.h>
Rakesh Iyer6642a682012-04-17 09:01:35 +000013#include <key_matrix.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>
Tom Warren150c2492012-09-19 15:50:56 -070019#include <asm/arch-tegra/timer.h>
Rakesh Iyer6642a682012-04-17 09:01:35 +000020#include <linux/input.h>
21
22DECLARE_GLOBAL_DATA_PTR;
23
24enum {
25 KBC_MAX_GPIO = 24,
26 KBC_MAX_KPENT = 8, /* size of keypress entry queue */
27};
28
29#define KBC_FIFO_TH_CNT_SHIFT 14
30#define KBC_DEBOUNCE_CNT_SHIFT 4
31#define KBC_CONTROL_FIFO_CNT_INT_EN (1 << 3)
32#define KBC_CONTROL_KBC_EN (1 << 0)
33#define KBC_INT_FIFO_CNT_INT_STATUS (1 << 2)
34#define KBC_KPENT_VALID (1 << 7)
35#define KBC_ST_STATUS (1 << 3)
36
37enum {
38 KBC_DEBOUNCE_COUNT = 2,
39 KBC_REPEAT_RATE_MS = 30,
40 KBC_REPEAT_DELAY_MS = 240,
41 KBC_CLOCK_KHZ = 32, /* Keyboard uses a 32KHz clock */
42};
43
44/* keyboard controller config and state */
Simon Glassf77f5e92015-10-18 21:17:16 -060045struct tegra_kbd_priv {
46 struct input_config *input; /* The input layer */
Rakesh Iyer6642a682012-04-17 09:01:35 +000047 struct key_matrix matrix; /* The key matrix layer */
48
49 struct kbc_tegra *kbc; /* tegra keyboard controller */
50 unsigned char inited; /* 1 if keyboard has been inited */
51 unsigned char first_scan; /* 1 if this is our first key scan */
52
53 /*
54 * After init we must wait a short time before polling the keyboard.
55 * This gives the tegra keyboard controller time to react after reset
56 * and lets us grab keys pressed during reset.
57 */
58 unsigned int init_dly_ms; /* Delay before we can read keyboard */
59 unsigned int start_time_ms; /* Time that we inited (in ms) */
60 unsigned int last_poll_ms; /* Time we should last polled */
61 unsigned int next_repeat_ms; /* Next time we repeat a key */
Simon Glassf77f5e92015-10-18 21:17:16 -060062};
Rakesh Iyer6642a682012-04-17 09:01:35 +000063
64/**
65 * reads the keyboard fifo for current keypresses
66 *
Simon Glassf77f5e92015-10-18 21:17:16 -060067 * @param priv Keyboard private data
Rakesh Iyer6642a682012-04-17 09:01:35 +000068 * @param fifo Place to put fifo results
69 * @param max_keycodes Maximum number of key codes to put in the fifo
70 * @return number of items put into fifo
71 */
Simon Glassf77f5e92015-10-18 21:17:16 -060072static int tegra_kbc_find_keys(struct tegra_kbd_priv *priv, int *fifo,
Rakesh Iyer6642a682012-04-17 09:01:35 +000073 int max_keycodes)
74{
75 struct key_matrix_key keys[KBC_MAX_KPENT], *key;
76 u32 kp_ent = 0;
77 int i;
78
79 for (key = keys, i = 0; i < KBC_MAX_KPENT; i++, key++) {
80 /* Get next word */
81 if (!(i & 3))
Simon Glassf77f5e92015-10-18 21:17:16 -060082 kp_ent = readl(&priv->kbc->kp_ent[i / 4]);
Rakesh Iyer6642a682012-04-17 09:01:35 +000083
84 key->valid = (kp_ent & KBC_KPENT_VALID) != 0;
85 key->row = (kp_ent >> 3) & 0xf;
86 key->col = kp_ent & 0x7;
87
88 /* Shift to get next entry */
89 kp_ent >>= 8;
90 }
Simon Glassf77f5e92015-10-18 21:17:16 -060091 return key_matrix_decode(&priv->matrix, keys, KBC_MAX_KPENT, fifo,
Rakesh Iyer6642a682012-04-17 09:01:35 +000092 max_keycodes);
93}
94
95/**
96 * Process all the keypress sequences in fifo and send key codes
97 *
98 * The fifo contains zero or more keypress sets. Each set
99 * consists of from 1-8 keycodes, representing the keycodes which
100 * were simultaneously pressed during that scan.
101 *
102 * This function works through each set and generates ASCII characters
103 * for each. Not that one set may produce more than one ASCII characters -
104 * for example holding down 'd' and 'f' at the same time will generate
105 * two ASCII characters.
106 *
107 * Note: if fifo_cnt is 0, we will tell the input layer that no keys are
108 * pressed.
109 *
Simon Glassf77f5e92015-10-18 21:17:16 -0600110 * @param priv Keyboard private data
Rakesh Iyer6642a682012-04-17 09:01:35 +0000111 * @param fifo_cnt Number of entries in the keyboard fifo
112 */
Simon Glassf77f5e92015-10-18 21:17:16 -0600113static void process_fifo(struct tegra_kbd_priv *priv, int fifo_cnt)
Rakesh Iyer6642a682012-04-17 09:01:35 +0000114{
115 int fifo[KBC_MAX_KPENT];
116 int cnt = 0;
117
118 /* Always call input_send_keycodes() at least once */
119 do {
120 if (fifo_cnt)
Simon Glassf77f5e92015-10-18 21:17:16 -0600121 cnt = tegra_kbc_find_keys(priv, fifo, KBC_MAX_KPENT);
Rakesh Iyer6642a682012-04-17 09:01:35 +0000122
Simon Glassf77f5e92015-10-18 21:17:16 -0600123 input_send_keycodes(priv->input, fifo, cnt);
Rakesh Iyer6642a682012-04-17 09:01:35 +0000124 } while (--fifo_cnt > 0);
125}
126
127/**
128 * Check the keyboard controller and emit ASCII characters for any keys that
129 * are pressed.
130 *
Simon Glassf77f5e92015-10-18 21:17:16 -0600131 * @param priv Keyboard private data
Rakesh Iyer6642a682012-04-17 09:01:35 +0000132 */
Simon Glassf77f5e92015-10-18 21:17:16 -0600133static void check_for_keys(struct tegra_kbd_priv *priv)
Rakesh Iyer6642a682012-04-17 09:01:35 +0000134{
135 int fifo_cnt;
136
Simon Glassf77f5e92015-10-18 21:17:16 -0600137 if (!priv->first_scan &&
138 get_timer(priv->last_poll_ms) < KBC_REPEAT_RATE_MS)
Rakesh Iyer6642a682012-04-17 09:01:35 +0000139 return;
Simon Glassf77f5e92015-10-18 21:17:16 -0600140 priv->last_poll_ms = get_timer(0);
141 priv->first_scan = 0;
Rakesh Iyer6642a682012-04-17 09:01:35 +0000142
143 /*
144 * Once we get here we know the keyboard has been scanned. So if there
145 * scan waiting for us, we know that nothing is held down.
146 */
Simon Glassf77f5e92015-10-18 21:17:16 -0600147 fifo_cnt = (readl(&priv->kbc->interrupt) >> 4) & 0xf;
148 process_fifo(priv, fifo_cnt);
Rakesh Iyer6642a682012-04-17 09:01:35 +0000149}
150
151/**
152 * In order to detect keys pressed on boot, wait for the hardware to
153 * complete scanning the keys. This includes time to transition from
154 * Wkup mode to Continous polling mode and the repoll time. We can
155 * deduct the time that's already elapsed.
156 *
Simon Glassf77f5e92015-10-18 21:17:16 -0600157 * @param priv Keyboard private data
Rakesh Iyer6642a682012-04-17 09:01:35 +0000158 */
Simon Glassf77f5e92015-10-18 21:17:16 -0600159static void kbd_wait_for_fifo_init(struct tegra_kbd_priv *priv)
Rakesh Iyer6642a682012-04-17 09:01:35 +0000160{
Simon Glassf77f5e92015-10-18 21:17:16 -0600161 if (!priv->inited) {
Rakesh Iyer6642a682012-04-17 09:01:35 +0000162 unsigned long elapsed_time;
163 long delay_ms;
164
Simon Glassf77f5e92015-10-18 21:17:16 -0600165 elapsed_time = get_timer(priv->start_time_ms);
166 delay_ms = priv->init_dly_ms - elapsed_time;
Rakesh Iyer6642a682012-04-17 09:01:35 +0000167 if (delay_ms > 0) {
168 udelay(delay_ms * 1000);
169 debug("%s: delay %ldms\n", __func__, delay_ms);
170 }
171
Simon Glassf77f5e92015-10-18 21:17:16 -0600172 priv->inited = 1;
Rakesh Iyer6642a682012-04-17 09:01:35 +0000173 }
174}
175
176/**
177 * Check the tegra keyboard, and send any keys that are pressed.
178 *
179 * This is called by input_tstc() and input_getc() when they need more
180 * characters
181 *
182 * @param input Input configuration
183 * @return 1, to indicate that we have something to look at
184 */
Jeroen Hofstee19d7bf32014-10-08 22:57:46 +0200185static int tegra_kbc_check(struct input_config *input)
Rakesh Iyer6642a682012-04-17 09:01:35 +0000186{
Simon Glassf77f5e92015-10-18 21:17:16 -0600187 struct tegra_kbd_priv *priv = dev_get_priv(input->dev);
188
189 kbd_wait_for_fifo_init(priv);
190 check_for_keys(priv);
Rakesh Iyer6642a682012-04-17 09:01:35 +0000191
192 return 1;
193}
194
Rakesh Iyer6642a682012-04-17 09:01:35 +0000195/* configures keyboard GPIO registers to use the rows and columns */
Simon Glassf77f5e92015-10-18 21:17:16 -0600196static void config_kbc_gpio(struct tegra_kbd_priv *priv, struct kbc_tegra *kbc)
Rakesh Iyer6642a682012-04-17 09:01:35 +0000197{
198 int i;
199
200 for (i = 0; i < KBC_MAX_GPIO; i++) {
201 u32 row_cfg, col_cfg;
202 u32 r_shift = 5 * (i % 6);
203 u32 c_shift = 4 * (i % 8);
204 u32 r_mask = 0x1f << r_shift;
205 u32 c_mask = 0xf << c_shift;
206 u32 r_offs = i / 6;
207 u32 c_offs = i / 8;
208
209 row_cfg = readl(&kbc->row_cfg[r_offs]);
210 col_cfg = readl(&kbc->col_cfg[c_offs]);
211
212 row_cfg &= ~r_mask;
213 col_cfg &= ~c_mask;
214
Simon Glassf77f5e92015-10-18 21:17:16 -0600215 if (i < priv->matrix.num_rows) {
Rakesh Iyer6642a682012-04-17 09:01:35 +0000216 row_cfg |= ((i << 1) | 1) << r_shift;
217 } else {
Simon Glassf77f5e92015-10-18 21:17:16 -0600218 col_cfg |= (((i - priv->matrix.num_rows) << 1) | 1)
Rakesh Iyer6642a682012-04-17 09:01:35 +0000219 << c_shift;
220 }
221
222 writel(row_cfg, &kbc->row_cfg[r_offs]);
223 writel(col_cfg, &kbc->col_cfg[c_offs]);
224 }
225}
226
227/**
228 * Start up the keyboard device
229 */
Simon Glassf77f5e92015-10-18 21:17:16 -0600230static void tegra_kbc_open(struct tegra_kbd_priv *priv)
Rakesh Iyer6642a682012-04-17 09:01:35 +0000231{
Simon Glassf77f5e92015-10-18 21:17:16 -0600232 struct kbc_tegra *kbc = priv->kbc;
Rakesh Iyer6642a682012-04-17 09:01:35 +0000233 unsigned int scan_period;
234 u32 val;
235
236 /*
237 * We will scan at twice the keyboard repeat rate, so that there is
238 * always a scan ready when we check it in check_for_keys().
239 */
240 scan_period = KBC_REPEAT_RATE_MS / 2;
241 writel(scan_period * KBC_CLOCK_KHZ, &kbc->rpt_dly);
242 writel(scan_period * KBC_CLOCK_KHZ, &kbc->init_dly);
243 /*
244 * Before reading from the keyboard we must wait for the init_dly
245 * plus the rpt_delay, plus 2ms for the row scan time.
246 */
Simon Glassf77f5e92015-10-18 21:17:16 -0600247 priv->init_dly_ms = scan_period * 2 + 2;
Rakesh Iyer6642a682012-04-17 09:01:35 +0000248
249 val = KBC_DEBOUNCE_COUNT << KBC_DEBOUNCE_CNT_SHIFT;
250 val |= 1 << KBC_FIFO_TH_CNT_SHIFT; /* fifo interrupt threshold */
251 val |= KBC_CONTROL_KBC_EN; /* enable */
252 writel(val, &kbc->control);
253
Simon Glassf77f5e92015-10-18 21:17:16 -0600254 priv->start_time_ms = get_timer(0);
255 priv->last_poll_ms = get_timer(0);
256 priv->next_repeat_ms = priv->last_poll_ms;
257 priv->first_scan = 1;
258}
259
260static int tegra_kbd_start(struct udevice *dev)
261{
262 struct tegra_kbd_priv *priv = dev_get_priv(dev);
263
264 /* Set up pin mux and enable the clock */
265 funcmux_select(PERIPH_ID_KBC, FUNCMUX_DEFAULT);
266 clock_enable(PERIPH_ID_KBC);
267 config_kbc_gpio(priv, priv->kbc);
268
269 tegra_kbc_open(priv);
270 debug("%s: Tegra keyboard ready\n", __func__);
271
272 return 0;
Rakesh Iyer6642a682012-04-17 09:01:35 +0000273}
274
275/**
276 * Set up the tegra keyboard. This is called by the stdio device handler
277 *
278 * We want to do this init when the keyboard is actually used rather than
279 * at start-up, since keyboard input may not currently be selected.
280 *
281 * Once the keyboard starts there will be a period during which we must
282 * wait for the keyboard to init. We do this only when a key is first
283 * read - see kbd_wait_for_fifo_init().
284 *
285 * @return 0 if ok, -ve on error
286 */
Simon Glassf77f5e92015-10-18 21:17:16 -0600287static int tegra_kbd_probe(struct udevice *dev)
Rakesh Iyer6642a682012-04-17 09:01:35 +0000288{
Simon Glassf77f5e92015-10-18 21:17:16 -0600289 struct tegra_kbd_priv *priv = dev_get_priv(dev);
290 struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev);
291 struct stdio_dev *sdev = &uc_priv->sdev;
292 struct input_config *input = &uc_priv->input;
Simon Glassf77f5e92015-10-18 21:17:16 -0600293 int ret;
Allen Martin1ed0b512012-11-01 13:41:16 +0000294
Simon Glassa821c4a2017-05-17 17:18:05 -0600295 priv->kbc = (struct kbc_tegra *)devfdt_get_addr(dev);
Simon Glassf77f5e92015-10-18 21:17:16 -0600296 if ((fdt_addr_t)priv->kbc == FDT_ADDR_T_NONE) {
Rakesh Iyer6642a682012-04-17 09:01:35 +0000297 debug("%s: No keyboard register found\n", __func__);
Simon Glassf77f5e92015-10-18 21:17:16 -0600298 return -EINVAL;
Rakesh Iyer6642a682012-04-17 09:01:35 +0000299 }
Simon Glassf77f5e92015-10-18 21:17:16 -0600300 input_set_delays(input, KBC_REPEAT_DELAY_MS, KBC_REPEAT_RATE_MS);
Rakesh Iyer6642a682012-04-17 09:01:35 +0000301
302 /* Decode the keyboard matrix information (16 rows, 8 columns) */
Simon Glassf77f5e92015-10-18 21:17:16 -0600303 ret = key_matrix_init(&priv->matrix, 16, 8, 1);
304 if (ret) {
305 debug("%s: Could not init key matrix: %d\n", __func__, ret);
306 return ret;
Rakesh Iyer6642a682012-04-17 09:01:35 +0000307 }
Simon Glass8327d412017-05-18 20:09:53 -0600308 ret = key_matrix_decode_fdt(dev, &priv->matrix);
Simon Glassf77f5e92015-10-18 21:17:16 -0600309 if (ret) {
310 debug("%s: Could not decode key matrix from fdt: %d\n",
311 __func__, ret);
312 return ret;
Rakesh Iyer6642a682012-04-17 09:01:35 +0000313 }
Simon Glass73248472016-01-30 16:37:40 -0700314 input_add_tables(input, false);
Simon Glassf77f5e92015-10-18 21:17:16 -0600315 if (priv->matrix.fn_keycode) {
316 ret = input_add_table(input, KEY_FN, -1,
317 priv->matrix.fn_keycode,
318 priv->matrix.key_count);
319 if (ret) {
320 debug("%s: input_add_table() failed\n", __func__);
321 return ret;
322 }
Rakesh Iyer6642a682012-04-17 09:01:35 +0000323 }
Rakesh Iyer6642a682012-04-17 09:01:35 +0000324
325 /* Register the device. init_tegra_keyboard() will be called soon */
Simon Glassf77f5e92015-10-18 21:17:16 -0600326 priv->input = input;
327 input->dev = dev;
328 input->read_keys = tegra_kbc_check;
Simon Glassf77f5e92015-10-18 21:17:16 -0600329 strcpy(sdev->name, "tegra-kbc");
330 ret = input_stdio_register(sdev);
331 if (ret) {
332 debug("%s: input_stdio_register() failed\n", __func__);
333 return ret;
334 }
335
Allen Martin1ed0b512012-11-01 13:41:16 +0000336 return 0;
Rakesh Iyer6642a682012-04-17 09:01:35 +0000337}
Simon Glassf77f5e92015-10-18 21:17:16 -0600338
339static const struct keyboard_ops tegra_kbd_ops = {
340 .start = tegra_kbd_start,
341};
342
343static const struct udevice_id tegra_kbd_ids[] = {
344 { .compatible = "nvidia,tegra20-kbc" },
345 { }
346};
347
348U_BOOT_DRIVER(tegra_kbd) = {
349 .name = "tegra_kbd",
350 .id = UCLASS_KEYBOARD,
351 .of_match = tegra_kbd_ids,
352 .probe = tegra_kbd_probe,
353 .ops = &tegra_kbd_ops,
354 .priv_auto_alloc_size = sizeof(struct tegra_kbd_priv),
355};