3 * NVIDIA Corporation <www.nvidia.com>
5 * SPDX-License-Identifier: GPL-2.0+
13 #include <key_matrix.h>
14 #include <stdio_dev.h>
15 #include <tegra-kbc.h>
17 #include <asm/arch/clock.h>
18 #include <asm/arch/funcmux.h>
19 #include <asm/arch-tegra/timer.h>
20 #include <linux/input.h>
22 DECLARE_GLOBAL_DATA_PTR
;
26 KBC_MAX_KPENT
= 8, /* size of keypress entry queue */
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)
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 */
44 /* keyboard controller config and state */
45 struct tegra_kbd_priv
{
46 struct input_config
*input
; /* The input layer */
47 struct key_matrix matrix
; /* The key matrix layer */
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 */
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.
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 */
65 * reads the keyboard fifo for current keypresses
67 * @param priv Keyboard private data
68 * @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
72 static int tegra_kbc_find_keys(struct tegra_kbd_priv
*priv
, int *fifo
,
75 struct key_matrix_key keys
[KBC_MAX_KPENT
], *key
;
79 for (key
= keys
, i
= 0; i
< KBC_MAX_KPENT
; i
++, key
++) {
82 kp_ent
= readl(&priv
->kbc
->kp_ent
[i
/ 4]);
84 key
->valid
= (kp_ent
& KBC_KPENT_VALID
) != 0;
85 key
->row
= (kp_ent
>> 3) & 0xf;
86 key
->col
= kp_ent
& 0x7;
88 /* Shift to get next entry */
91 return key_matrix_decode(&priv
->matrix
, keys
, KBC_MAX_KPENT
, fifo
,
96 * Process all the keypress sequences in fifo and send key codes
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.
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.
107 * Note: if fifo_cnt is 0, we will tell the input layer that no keys are
110 * @param priv Keyboard private data
111 * @param fifo_cnt Number of entries in the keyboard fifo
113 static void process_fifo(struct tegra_kbd_priv
*priv
, int fifo_cnt
)
115 int fifo
[KBC_MAX_KPENT
];
118 /* Always call input_send_keycodes() at least once */
121 cnt
= tegra_kbc_find_keys(priv
, fifo
, KBC_MAX_KPENT
);
123 input_send_keycodes(priv
->input
, fifo
, cnt
);
124 } while (--fifo_cnt
> 0);
128 * Check the keyboard controller and emit ASCII characters for any keys that
131 * @param priv Keyboard private data
133 static void check_for_keys(struct tegra_kbd_priv
*priv
)
137 if (!priv
->first_scan
&&
138 get_timer(priv
->last_poll_ms
) < KBC_REPEAT_RATE_MS
)
140 priv
->last_poll_ms
= get_timer(0);
141 priv
->first_scan
= 0;
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.
147 fifo_cnt
= (readl(&priv
->kbc
->interrupt
) >> 4) & 0xf;
148 process_fifo(priv
, fifo_cnt
);
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.
157 * @param priv Keyboard private data
159 static void kbd_wait_for_fifo_init(struct tegra_kbd_priv
*priv
)
162 unsigned long elapsed_time
;
165 elapsed_time
= get_timer(priv
->start_time_ms
);
166 delay_ms
= priv
->init_dly_ms
- elapsed_time
;
168 udelay(delay_ms
* 1000);
169 debug("%s: delay %ldms\n", __func__
, delay_ms
);
177 * Check the tegra keyboard, and send any keys that are pressed.
179 * This is called by input_tstc() and input_getc() when they need more
182 * @param input Input configuration
183 * @return 1, to indicate that we have something to look at
185 static int tegra_kbc_check(struct input_config
*input
)
187 struct tegra_kbd_priv
*priv
= dev_get_priv(input
->dev
);
189 kbd_wait_for_fifo_init(priv
);
190 check_for_keys(priv
);
195 /* configures keyboard GPIO registers to use the rows and columns */
196 static void config_kbc_gpio(struct tegra_kbd_priv
*priv
, struct kbc_tegra
*kbc
)
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
;
209 row_cfg
= readl(&kbc
->row_cfg
[r_offs
]);
210 col_cfg
= readl(&kbc
->col_cfg
[c_offs
]);
215 if (i
< priv
->matrix
.num_rows
) {
216 row_cfg
|= ((i
<< 1) | 1) << r_shift
;
218 col_cfg
|= (((i
- priv
->matrix
.num_rows
) << 1) | 1)
222 writel(row_cfg
, &kbc
->row_cfg
[r_offs
]);
223 writel(col_cfg
, &kbc
->col_cfg
[c_offs
]);
228 * Start up the keyboard device
230 static void tegra_kbc_open(struct tegra_kbd_priv
*priv
)
232 struct kbc_tegra
*kbc
= priv
->kbc
;
233 unsigned int scan_period
;
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().
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
);
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.
247 priv
->init_dly_ms
= scan_period
* 2 + 2;
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
);
254 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;
260 static int tegra_kbd_start(struct udevice
*dev
)
262 struct tegra_kbd_priv
*priv
= dev_get_priv(dev
);
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
);
269 tegra_kbc_open(priv
);
270 debug("%s: Tegra keyboard ready\n", __func__
);
276 * Set up the tegra keyboard. This is called by the stdio device handler
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.
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().
285 * @return 0 if ok, -ve on error
287 static int tegra_kbd_probe(struct udevice
*dev
)
289 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
;
293 int node
= dev
->of_offset
;
296 priv
->kbc
= (struct kbc_tegra
*)dev_get_addr(dev
);
297 if ((fdt_addr_t
)priv
->kbc
== FDT_ADDR_T_NONE
) {
298 debug("%s: No keyboard register found\n", __func__
);
301 input_set_delays(input
, KBC_REPEAT_DELAY_MS
, KBC_REPEAT_RATE_MS
);
303 /* Decode the keyboard matrix information (16 rows, 8 columns) */
304 ret
= key_matrix_init(&priv
->matrix
, 16, 8, 1);
306 debug("%s: Could not init key matrix: %d\n", __func__
, ret
);
309 ret
= key_matrix_decode_fdt(&priv
->matrix
, gd
->fdt_blob
, node
);
311 debug("%s: Could not decode key matrix from fdt: %d\n",
315 if (priv
->matrix
.fn_keycode
) {
316 ret
= input_add_table(input
, KEY_FN
, -1,
317 priv
->matrix
.fn_keycode
,
318 priv
->matrix
.key_count
);
320 debug("%s: input_add_table() failed\n", __func__
);
325 /* Register the device. init_tegra_keyboard() will be called soon */
328 input
->read_keys
= tegra_kbc_check
;
329 input_add_tables(input
);
330 strcpy(sdev
->name
, "tegra-kbc");
331 ret
= input_stdio_register(sdev
);
333 debug("%s: input_stdio_register() failed\n", __func__
);
340 static const struct keyboard_ops tegra_kbd_ops
= {
341 .start
= tegra_kbd_start
,
344 static const struct udevice_id tegra_kbd_ids
[] = {
345 { .compatible
= "nvidia,tegra20-kbc" },
349 U_BOOT_DRIVER(tegra_kbd
) = {
351 .id
= UCLASS_KEYBOARD
,
352 .of_match
= tegra_kbd_ids
,
353 .probe
= tegra_kbd_probe
,
354 .ops
= &tegra_kbd_ops
,
355 .priv_auto_alloc_size
= sizeof(struct tegra_kbd_priv
),