1/*
2 * Copyright (C) 2014 Broadcom Corporation
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation version 2.
7 *
8 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9 * kind, whether express or implied; without even the implied warranty
10 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 */
13
14#include <linux/bitops.h>
15#include <linux/clk.h>
16#include <linux/gfp.h>
17#include <linux/io.h>
18#include <linux/input.h>
19#include <linux/input/matrix_keypad.h>
20#include <linux/interrupt.h>
21#include <linux/module.h>
22#include <linux/of.h>
23#include <linux/platform_device.h>
24#include <linux/stddef.h>
25#include <linux/types.h>
26
27#define DEFAULT_CLK_HZ 31250
28#define MAX_ROWS 8
29#define MAX_COLS 8
30
31/* Register/field definitions */
32#define KPCR_OFFSET 0x00000080
33#define KPCR_MODE 0x00000002
34#define KPCR_MODE_SHIFT 1
35#define KPCR_MODE_MASK 1
36#define KPCR_ENABLE 0x00000001
37#define KPCR_STATUSFILTERENABLE 0x00008000
38#define KPCR_STATUSFILTERTYPE_SHIFT 12
39#define KPCR_COLFILTERENABLE 0x00000800
40#define KPCR_COLFILTERTYPE_SHIFT 8
41#define KPCR_ROWWIDTH_SHIFT 20
42#define KPCR_COLUMNWIDTH_SHIFT 16
43
44#define KPIOR_OFFSET 0x00000084
45#define KPIOR_ROWOCONTRL_SHIFT 24
46#define KPIOR_ROWOCONTRL_MASK 0xFF000000
47#define KPIOR_COLUMNOCONTRL_SHIFT 16
48#define KPIOR_COLUMNOCONTRL_MASK 0x00FF0000
49#define KPIOR_COLUMN_IO_DATA_SHIFT 0
50
51#define KPEMR0_OFFSET 0x00000090
52#define KPEMR1_OFFSET 0x00000094
53#define KPEMR2_OFFSET 0x00000098
54#define KPEMR3_OFFSET 0x0000009C
55#define KPEMR_EDGETYPE_BOTH 3
56
57#define KPSSR0_OFFSET 0x000000A0
58#define KPSSR1_OFFSET 0x000000A4
59#define KPSSRN_OFFSET(reg_n) (KPSSR0_OFFSET + 4 * (reg_n))
60#define KPIMR0_OFFSET 0x000000B0
61#define KPIMR1_OFFSET 0x000000B4
62#define KPICR0_OFFSET 0x000000B8
63#define KPICR1_OFFSET 0x000000BC
64#define KPICRN_OFFSET(reg_n) (KPICR0_OFFSET + 4 * (reg_n))
65#define KPISR0_OFFSET 0x000000C0
66#define KPISR1_OFFSET 0x000000C4
67
68#define KPCR_STATUSFILTERTYPE_MAX 7
69#define KPCR_COLFILTERTYPE_MAX 7
70
71/* Macros to determine the row/column from a bit that is set in SSR0/1. */
72#define BIT_TO_ROW_SSRN(bit_nr, reg_n) (((bit_nr) >> 3) + 4 * (reg_n))
73#define BIT_TO_COL(bit_nr) ((bit_nr) % 8)
74
75/* Structure representing various run-time entities */
76struct bcm_kp {
77 void __iomem *base;
78 int irq;
79 struct clk *clk;
80 struct input_dev *input_dev;
81 unsigned long last_state[2];
82 unsigned int n_rows;
83 unsigned int n_cols;
84 u32 kpcr;
85 u32 kpior;
86 u32 kpemr;
87 u32 imr0_val;
88 u32 imr1_val;
89};
90
91/*
92 * Returns the keycode from the input device keymap given the row and
93 * column.
94 */
95static int bcm_kp_get_keycode(struct bcm_kp *kp, int row, int col)
96{
97 unsigned int row_shift = get_count_order(kp->n_cols);
98 unsigned short *keymap = kp->input_dev->keycode;
99
100 return keymap[MATRIX_SCAN_CODE(row, col, row_shift)];
101}
102
103static void bcm_kp_report_keys(struct bcm_kp *kp, int reg_num, int pull_mode)
104{
105 unsigned long state, change;
106 int bit_nr;
107 int key_press;
108 int row, col;
109 unsigned int keycode;
110
111 /* Clear interrupts */
112 writel(0xFFFFFFFF, kp->base + KPICRN_OFFSET(reg_num));
113
114 state = readl(kp->base + KPSSRN_OFFSET(reg_num));
115 change = kp->last_state[reg_num] ^ state;
116 kp->last_state[reg_num] = state;
117
118 for_each_set_bit(bit_nr, &change, BITS_PER_LONG) {
119 key_press = state & BIT(bit_nr);
120 /* The meaning of SSR register depends on pull mode. */
121 key_press = pull_mode ? !key_press : key_press;
122 row = BIT_TO_ROW_SSRN(bit_nr, reg_num);
123 col = BIT_TO_COL(bit_nr);
124 keycode = bcm_kp_get_keycode(kp, row, col);
125 input_report_key(kp->input_dev, keycode, key_press);
126 }
127}
128
129static irqreturn_t bcm_kp_isr_thread(int irq, void *dev_id)
130{
131 struct bcm_kp *kp = dev_id;
132 int pull_mode = (kp->kpcr >> KPCR_MODE_SHIFT) & KPCR_MODE_MASK;
133 int reg_num;
134
135 for (reg_num = 0; reg_num <= 1; reg_num++)
136 bcm_kp_report_keys(kp, reg_num, pull_mode);
137
138 input_sync(kp->input_dev);
139
140 return IRQ_HANDLED;
141}
142
143static int bcm_kp_start(struct bcm_kp *kp)
144{
145 int error;
146
147 if (kp->clk) {
148 error = clk_prepare_enable(kp->clk);
149 if (error)
150 return error;
151 }
152
153 writel(kp->kpior, kp->base + KPIOR_OFFSET);
154
155 writel(kp->imr0_val, kp->base + KPIMR0_OFFSET);
156 writel(kp->imr1_val, kp->base + KPIMR1_OFFSET);
157
158 writel(kp->kpemr, kp->base + KPEMR0_OFFSET);
159 writel(kp->kpemr, kp->base + KPEMR1_OFFSET);
160 writel(kp->kpemr, kp->base + KPEMR2_OFFSET);
161 writel(kp->kpemr, kp->base + KPEMR3_OFFSET);
162
163 writel(0xFFFFFFFF, kp->base + KPICR0_OFFSET);
164 writel(0xFFFFFFFF, kp->base + KPICR1_OFFSET);
165
166 kp->last_state[0] = readl(kp->base + KPSSR0_OFFSET);
167 kp->last_state[0] = readl(kp->base + KPSSR1_OFFSET);
168
169 writel(kp->kpcr | KPCR_ENABLE, kp->base + KPCR_OFFSET);
170
171 return 0;
172}
173
174static void bcm_kp_stop(const struct bcm_kp *kp)
175{
176 u32 val;
177
178 val = readl(kp->base + KPCR_OFFSET);
179 val &= ~KPCR_ENABLE;
180 writel(0, kp->base + KPCR_OFFSET);
181 writel(0, kp->base + KPIMR0_OFFSET);
182 writel(0, kp->base + KPIMR1_OFFSET);
183 writel(0xFFFFFFFF, kp->base + KPICR0_OFFSET);
184 writel(0xFFFFFFFF, kp->base + KPICR1_OFFSET);
185
186 if (kp->clk)
187 clk_disable_unprepare(kp->clk);
188}
189
190static int bcm_kp_open(struct input_dev *dev)
191{
192 struct bcm_kp *kp = input_get_drvdata(dev);
193
194 return bcm_kp_start(kp);
195}
196
197static void bcm_kp_close(struct input_dev *dev)
198{
199 struct bcm_kp *kp = input_get_drvdata(dev);
200
201 bcm_kp_stop(kp);
202}
203
204static int bcm_kp_matrix_key_parse_dt(struct bcm_kp *kp)
205{
206 struct device *dev = kp->input_dev->dev.parent;
207 struct device_node *np = dev->of_node;
208 int error;
209 unsigned int dt_val;
210 unsigned int i;
211 unsigned int num_rows, col_mask, rows_set;
212
213 /* Initialize the KPCR Keypad Configuration Register */
214 kp->kpcr = KPCR_STATUSFILTERENABLE | KPCR_COLFILTERENABLE;
215
216 error = matrix_keypad_parse_properties(dev, &kp->n_rows, &kp->n_cols);
217 if (error) {
218 dev_err(dev, "failed to parse kp params\n");
219 return error;
220 }
221
222 /* Set row width for the ASIC block. */
223 kp->kpcr |= (kp->n_rows - 1) << KPCR_ROWWIDTH_SHIFT;
224
225 /* Set column width for the ASIC block. */
226 kp->kpcr |= (kp->n_cols - 1) << KPCR_COLUMNWIDTH_SHIFT;
227
228 /* Configure the IMR registers */
229
230 /*
231 * IMR registers contain interrupt enable bits for 8x8 matrix
232 * IMR0 register format: <row3> <row2> <row1> <row0>
233 * IMR1 register format: <row7> <row6> <row5> <row4>
234 */
235 col_mask = (1 << (kp->n_cols)) - 1;
236 num_rows = kp->n_rows;
237
238 /* Set column bits in rows 0 to 3 in IMR0 */
239 kp->imr0_val = col_mask;
240
241 rows_set = 1;
242 while (--num_rows && rows_set++ < 4)
243 kp->imr0_val |= kp->imr0_val << MAX_COLS;
244
245 /* Set column bits in rows 4 to 7 in IMR1 */
246 kp->imr1_val = 0;
247 if (num_rows) {
248 kp->imr1_val = col_mask;
249 while (--num_rows)
250 kp->imr1_val |= kp->imr1_val << MAX_COLS;
251 }
252
253 /* Initialize the KPEMR Keypress Edge Mode Registers */
254 /* Trigger on both edges */
255 kp->kpemr = 0;
256 for (i = 0; i <= 30; i += 2)
257 kp->kpemr |= (KPEMR_EDGETYPE_BOTH << i);
258
259 /*
260 * Obtain the Status filter debounce value and verify against the
261 * possible values specified in the DT binding.
262 */
263 of_property_read_u32(np, "status-debounce-filter-period", &dt_val);
264
265 if (dt_val > KPCR_STATUSFILTERTYPE_MAX) {
266 dev_err(dev, "Invalid Status filter debounce value %d\n",
267 dt_val);
268 return -EINVAL;
269 }
270
271 kp->kpcr |= dt_val << KPCR_STATUSFILTERTYPE_SHIFT;
272
273 /*
274 * Obtain the Column filter debounce value and verify against the
275 * possible values specified in the DT binding.
276 */
277 of_property_read_u32(np, "col-debounce-filter-period", &dt_val);
278
279 if (dt_val > KPCR_COLFILTERTYPE_MAX) {
280 dev_err(dev, "Invalid Column filter debounce value %d\n",
281 dt_val);
282 return -EINVAL;
283 }
284
285 kp->kpcr |= dt_val << KPCR_COLFILTERTYPE_SHIFT;
286
287 /*
288 * Determine between the row and column,
289 * which should be configured as output.
290 */
291 if (of_property_read_bool(np, "row-output-enabled")) {
292 /*
293 * Set RowOContrl or ColumnOContrl in KPIOR
294 * to the number of pins to drive as outputs
295 */
296 kp->kpior = ((1 << kp->n_rows) - 1) <<
297 KPIOR_ROWOCONTRL_SHIFT;
298 } else {
299 kp->kpior = ((1 << kp->n_cols) - 1) <<
300 KPIOR_COLUMNOCONTRL_SHIFT;
301 }
302
303 /*
304 * Determine if the scan pull up needs to be enabled
305 */
306 if (of_property_read_bool(np, "pull-up-enabled"))
307 kp->kpcr |= KPCR_MODE;
308
309 dev_dbg(dev, "n_rows=%d n_col=%d kpcr=%x kpior=%x kpemr=%x\n",
310 kp->n_rows, kp->n_cols,
311 kp->kpcr, kp->kpior, kp->kpemr);
312
313 return 0;
314}
315
316
317static int bcm_kp_probe(struct platform_device *pdev)
318{
319 struct bcm_kp *kp;
320 struct input_dev *input_dev;
321 struct resource *res;
322 int error;
323
324 kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);
325 if (!kp)
326 return -ENOMEM;
327
328 input_dev = devm_input_allocate_device(&pdev->dev);
329 if (!input_dev) {
330 dev_err(&pdev->dev, "failed to allocate the input device\n");
331 return -ENOMEM;
332 }
333
334 __set_bit(EV_KEY, input_dev->evbit);
335
336 /* Enable auto repeat feature of Linux input subsystem */
337 if (of_property_read_bool(pdev->dev.of_node, "autorepeat"))
338 __set_bit(EV_REP, input_dev->evbit);
339
340 input_dev->name = pdev->name;
341 input_dev->phys = "keypad/input0";
342 input_dev->dev.parent = &pdev->dev;
343 input_dev->open = bcm_kp_open;
344 input_dev->close = bcm_kp_close;
345
346 input_dev->id.bustype = BUS_HOST;
347 input_dev->id.vendor = 0x0001;
348 input_dev->id.product = 0x0001;
349 input_dev->id.version = 0x0100;
350
351 input_set_drvdata(input_dev, kp);
352
353 kp->input_dev = input_dev;
354
355 error = bcm_kp_matrix_key_parse_dt(kp);
356 if (error)
357 return error;
358
359 error = matrix_keypad_build_keymap(NULL, NULL,
360 kp->n_rows, kp->n_cols,
361 NULL, input_dev);
362 if (error) {
363 dev_err(&pdev->dev, "failed to build keymap\n");
364 return error;
365 }
366
367 /* Get the KEYPAD base address */
368 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
369 if (!res) {
370 dev_err(&pdev->dev, "Missing keypad base address resource\n");
371 return -ENODEV;
372 }
373
374 kp->base = devm_ioremap_resource(&pdev->dev, res);
375 if (IS_ERR(kp->base))
376 return PTR_ERR(kp->base);
377
378 /* Enable clock */
379 kp->clk = devm_clk_get(&pdev->dev, "peri_clk");
380 if (IS_ERR(kp->clk)) {
381 error = PTR_ERR(kp->clk);
382 if (error != -ENOENT) {
383 if (error != -EPROBE_DEFER)
384 dev_err(&pdev->dev, "Failed to get clock\n");
385 return error;
386 }
387 dev_dbg(&pdev->dev,
388 "No clock specified. Assuming it's enabled\n");
389 kp->clk = NULL;
390 } else {
391 unsigned int desired_rate;
392 long actual_rate;
393
394 error = of_property_read_u32(pdev->dev.of_node,
395 "clock-frequency", &desired_rate);
396 if (error < 0)
397 desired_rate = DEFAULT_CLK_HZ;
398
399 actual_rate = clk_round_rate(kp->clk, desired_rate);
400 if (actual_rate <= 0)
401 return -EINVAL;
402
403 error = clk_set_rate(kp->clk, actual_rate);
404 if (error)
405 return error;
406
407 error = clk_prepare_enable(kp->clk);
408 if (error)
409 return error;
410 }
411
412 /* Put the kp into a known sane state */
413 bcm_kp_stop(kp);
414
415 kp->irq = platform_get_irq(pdev, 0);
416 if (kp->irq < 0) {
417 dev_err(&pdev->dev, "no IRQ specified\n");
418 return -EINVAL;
419 }
420
421 error = devm_request_threaded_irq(&pdev->dev, kp->irq,
422 NULL, bcm_kp_isr_thread,
423 IRQF_ONESHOT, pdev->name, kp);
424 if (error) {
425 dev_err(&pdev->dev, "failed to request IRQ\n");
426 return error;
427 }
428
429 error = input_register_device(input_dev);
430 if (error) {
431 dev_err(&pdev->dev, "failed to register input device\n");
432 return error;
433 }
434
435 return 0;
436}
437
438static const struct of_device_id bcm_kp_of_match[] = {
439 { .compatible = "brcm,bcm-keypad" },
440 { },
441};
442MODULE_DEVICE_TABLE(of, bcm_kp_of_match);
443
444static struct platform_driver bcm_kp_device_driver = {
445 .probe = bcm_kp_probe,
446 .driver = {
447 .name = "bcm-keypad",
448 .of_match_table = of_match_ptr(bcm_kp_of_match),
449 }
450};
451
452module_platform_driver(bcm_kp_device_driver);
453
454MODULE_AUTHOR("Broadcom Corporation");
455MODULE_DESCRIPTION("BCM Keypad Driver");
456MODULE_LICENSE("GPL v2");
457