1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright (C) 2014 Broadcom Corporation
3
4 #include <linux/bitops.h>
5 #include <linux/clk.h>
6 #include <linux/gfp.h>
7 #include <linux/io.h>
8 #include <linux/input.h>
9 #include <linux/input/matrix_keypad.h>
10 #include <linux/interrupt.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/platform_device.h>
14 #include <linux/stddef.h>
15 #include <linux/types.h>
16
17 #define DEFAULT_CLK_HZ 31250
18 #define MAX_ROWS 8
19 #define MAX_COLS 8
20
21 /* Register/field definitions */
22 #define KPCR_OFFSET 0x00000080
23 #define KPCR_MODE 0x00000002
24 #define KPCR_MODE_SHIFT 1
25 #define KPCR_MODE_MASK 1
26 #define KPCR_ENABLE 0x00000001
27 #define KPCR_STATUSFILTERENABLE 0x00008000
28 #define KPCR_STATUSFILTERTYPE_SHIFT 12
29 #define KPCR_COLFILTERENABLE 0x00000800
30 #define KPCR_COLFILTERTYPE_SHIFT 8
31 #define KPCR_ROWWIDTH_SHIFT 20
32 #define KPCR_COLUMNWIDTH_SHIFT 16
33
34 #define KPIOR_OFFSET 0x00000084
35 #define KPIOR_ROWOCONTRL_SHIFT 24
36 #define KPIOR_ROWOCONTRL_MASK 0xFF000000
37 #define KPIOR_COLUMNOCONTRL_SHIFT 16
38 #define KPIOR_COLUMNOCONTRL_MASK 0x00FF0000
39 #define KPIOR_COLUMN_IO_DATA_SHIFT 0
40
41 #define KPEMR0_OFFSET 0x00000090
42 #define KPEMR1_OFFSET 0x00000094
43 #define KPEMR2_OFFSET 0x00000098
44 #define KPEMR3_OFFSET 0x0000009C
45 #define KPEMR_EDGETYPE_BOTH 3
46
47 #define KPSSR0_OFFSET 0x000000A0
48 #define KPSSR1_OFFSET 0x000000A4
49 #define KPSSRN_OFFSET(reg_n) (KPSSR0_OFFSET + 4 * (reg_n))
50 #define KPIMR0_OFFSET 0x000000B0
51 #define KPIMR1_OFFSET 0x000000B4
52 #define KPICR0_OFFSET 0x000000B8
53 #define KPICR1_OFFSET 0x000000BC
54 #define KPICRN_OFFSET(reg_n) (KPICR0_OFFSET + 4 * (reg_n))
55 #define KPISR0_OFFSET 0x000000C0
56 #define KPISR1_OFFSET 0x000000C4
57
58 #define KPCR_STATUSFILTERTYPE_MAX 7
59 #define KPCR_COLFILTERTYPE_MAX 7
60
61 /* Macros to determine the row/column from a bit that is set in SSR0/1. */
62 #define BIT_TO_ROW_SSRN(bit_nr, reg_n) (((bit_nr) >> 3) + 4 * (reg_n))
63 #define BIT_TO_COL(bit_nr) ((bit_nr) % 8)
64
65 /* Structure representing various run-time entities */
66 struct bcm_kp {
67 void __iomem *base;
68 int irq;
69 struct clk *clk;
70 struct input_dev *input_dev;
71 unsigned long last_state[2];
72 unsigned int n_rows;
73 unsigned int n_cols;
74 u32 kpcr;
75 u32 kpior;
76 u32 kpemr;
77 u32 imr0_val;
78 u32 imr1_val;
79 };
80
81 /*
82 * Returns the keycode from the input device keymap given the row and
83 * column.
84 */
bcm_kp_get_keycode(struct bcm_kp * kp,int row,int col)85 static int bcm_kp_get_keycode(struct bcm_kp *kp, int row, int col)
86 {
87 unsigned int row_shift = get_count_order(kp->n_cols);
88 unsigned short *keymap = kp->input_dev->keycode;
89
90 return keymap[MATRIX_SCAN_CODE(row, col, row_shift)];
91 }
92
bcm_kp_report_keys(struct bcm_kp * kp,int reg_num,int pull_mode)93 static void bcm_kp_report_keys(struct bcm_kp *kp, int reg_num, int pull_mode)
94 {
95 unsigned long state, change;
96 int bit_nr;
97 int key_press;
98 int row, col;
99 unsigned int keycode;
100
101 /* Clear interrupts */
102 writel(0xFFFFFFFF, kp->base + KPICRN_OFFSET(reg_num));
103
104 state = readl(kp->base + KPSSRN_OFFSET(reg_num));
105 change = kp->last_state[reg_num] ^ state;
106 kp->last_state[reg_num] = state;
107
108 for_each_set_bit(bit_nr, &change, BITS_PER_LONG) {
109 key_press = state & BIT(bit_nr);
110 /* The meaning of SSR register depends on pull mode. */
111 key_press = pull_mode ? !key_press : key_press;
112 row = BIT_TO_ROW_SSRN(bit_nr, reg_num);
113 col = BIT_TO_COL(bit_nr);
114 keycode = bcm_kp_get_keycode(kp, row, col);
115 input_report_key(kp->input_dev, keycode, key_press);
116 }
117 }
118
bcm_kp_isr_thread(int irq,void * dev_id)119 static irqreturn_t bcm_kp_isr_thread(int irq, void *dev_id)
120 {
121 struct bcm_kp *kp = dev_id;
122 int pull_mode = (kp->kpcr >> KPCR_MODE_SHIFT) & KPCR_MODE_MASK;
123 int reg_num;
124
125 for (reg_num = 0; reg_num <= 1; reg_num++)
126 bcm_kp_report_keys(kp, reg_num, pull_mode);
127
128 input_sync(kp->input_dev);
129
130 return IRQ_HANDLED;
131 }
132
bcm_kp_start(struct bcm_kp * kp)133 static int bcm_kp_start(struct bcm_kp *kp)
134 {
135 int error;
136
137 if (kp->clk) {
138 error = clk_prepare_enable(kp->clk);
139 if (error)
140 return error;
141 }
142
143 writel(kp->kpior, kp->base + KPIOR_OFFSET);
144
145 writel(kp->imr0_val, kp->base + KPIMR0_OFFSET);
146 writel(kp->imr1_val, kp->base + KPIMR1_OFFSET);
147
148 writel(kp->kpemr, kp->base + KPEMR0_OFFSET);
149 writel(kp->kpemr, kp->base + KPEMR1_OFFSET);
150 writel(kp->kpemr, kp->base + KPEMR2_OFFSET);
151 writel(kp->kpemr, kp->base + KPEMR3_OFFSET);
152
153 writel(0xFFFFFFFF, kp->base + KPICR0_OFFSET);
154 writel(0xFFFFFFFF, kp->base + KPICR1_OFFSET);
155
156 kp->last_state[0] = readl(kp->base + KPSSR0_OFFSET);
157 kp->last_state[0] = readl(kp->base + KPSSR1_OFFSET);
158
159 writel(kp->kpcr | KPCR_ENABLE, kp->base + KPCR_OFFSET);
160
161 return 0;
162 }
163
bcm_kp_stop(const struct bcm_kp * kp)164 static void bcm_kp_stop(const struct bcm_kp *kp)
165 {
166 u32 val;
167
168 val = readl(kp->base + KPCR_OFFSET);
169 val &= ~KPCR_ENABLE;
170 writel(0, kp->base + KPCR_OFFSET);
171 writel(0, kp->base + KPIMR0_OFFSET);
172 writel(0, kp->base + KPIMR1_OFFSET);
173 writel(0xFFFFFFFF, kp->base + KPICR0_OFFSET);
174 writel(0xFFFFFFFF, kp->base + KPICR1_OFFSET);
175
176 clk_disable_unprepare(kp->clk);
177 }
178
bcm_kp_open(struct input_dev * dev)179 static int bcm_kp_open(struct input_dev *dev)
180 {
181 struct bcm_kp *kp = input_get_drvdata(dev);
182
183 return bcm_kp_start(kp);
184 }
185
bcm_kp_close(struct input_dev * dev)186 static void bcm_kp_close(struct input_dev *dev)
187 {
188 struct bcm_kp *kp = input_get_drvdata(dev);
189
190 bcm_kp_stop(kp);
191 }
192
bcm_kp_matrix_key_parse_dt(struct bcm_kp * kp)193 static int bcm_kp_matrix_key_parse_dt(struct bcm_kp *kp)
194 {
195 struct device *dev = kp->input_dev->dev.parent;
196 struct device_node *np = dev->of_node;
197 int error;
198 unsigned int dt_val;
199 unsigned int i;
200 unsigned int num_rows, col_mask, rows_set;
201
202 /* Initialize the KPCR Keypad Configuration Register */
203 kp->kpcr = KPCR_STATUSFILTERENABLE | KPCR_COLFILTERENABLE;
204
205 error = matrix_keypad_parse_properties(dev, &kp->n_rows, &kp->n_cols);
206 if (error) {
207 dev_err(dev, "failed to parse kp params\n");
208 return error;
209 }
210
211 /* Set row width for the ASIC block. */
212 kp->kpcr |= (kp->n_rows - 1) << KPCR_ROWWIDTH_SHIFT;
213
214 /* Set column width for the ASIC block. */
215 kp->kpcr |= (kp->n_cols - 1) << KPCR_COLUMNWIDTH_SHIFT;
216
217 /* Configure the IMR registers */
218
219 /*
220 * IMR registers contain interrupt enable bits for 8x8 matrix
221 * IMR0 register format: <row3> <row2> <row1> <row0>
222 * IMR1 register format: <row7> <row6> <row5> <row4>
223 */
224 col_mask = (1 << (kp->n_cols)) - 1;
225 num_rows = kp->n_rows;
226
227 /* Set column bits in rows 0 to 3 in IMR0 */
228 kp->imr0_val = col_mask;
229
230 rows_set = 1;
231 while (--num_rows && rows_set++ < 4)
232 kp->imr0_val |= kp->imr0_val << MAX_COLS;
233
234 /* Set column bits in rows 4 to 7 in IMR1 */
235 kp->imr1_val = 0;
236 if (num_rows) {
237 kp->imr1_val = col_mask;
238 while (--num_rows)
239 kp->imr1_val |= kp->imr1_val << MAX_COLS;
240 }
241
242 /* Initialize the KPEMR Keypress Edge Mode Registers */
243 /* Trigger on both edges */
244 kp->kpemr = 0;
245 for (i = 0; i <= 30; i += 2)
246 kp->kpemr |= (KPEMR_EDGETYPE_BOTH << i);
247
248 /*
249 * Obtain the Status filter debounce value and verify against the
250 * possible values specified in the DT binding.
251 */
252 of_property_read_u32(np, "status-debounce-filter-period", &dt_val);
253
254 if (dt_val > KPCR_STATUSFILTERTYPE_MAX) {
255 dev_err(dev, "Invalid Status filter debounce value %d\n",
256 dt_val);
257 return -EINVAL;
258 }
259
260 kp->kpcr |= dt_val << KPCR_STATUSFILTERTYPE_SHIFT;
261
262 /*
263 * Obtain the Column filter debounce value and verify against the
264 * possible values specified in the DT binding.
265 */
266 of_property_read_u32(np, "col-debounce-filter-period", &dt_val);
267
268 if (dt_val > KPCR_COLFILTERTYPE_MAX) {
269 dev_err(dev, "Invalid Column filter debounce value %d\n",
270 dt_val);
271 return -EINVAL;
272 }
273
274 kp->kpcr |= dt_val << KPCR_COLFILTERTYPE_SHIFT;
275
276 /*
277 * Determine between the row and column,
278 * which should be configured as output.
279 */
280 if (of_property_read_bool(np, "row-output-enabled")) {
281 /*
282 * Set RowOContrl or ColumnOContrl in KPIOR
283 * to the number of pins to drive as outputs
284 */
285 kp->kpior = ((1 << kp->n_rows) - 1) <<
286 KPIOR_ROWOCONTRL_SHIFT;
287 } else {
288 kp->kpior = ((1 << kp->n_cols) - 1) <<
289 KPIOR_COLUMNOCONTRL_SHIFT;
290 }
291
292 /*
293 * Determine if the scan pull up needs to be enabled
294 */
295 if (of_property_read_bool(np, "pull-up-enabled"))
296 kp->kpcr |= KPCR_MODE;
297
298 dev_dbg(dev, "n_rows=%d n_col=%d kpcr=%x kpior=%x kpemr=%x\n",
299 kp->n_rows, kp->n_cols,
300 kp->kpcr, kp->kpior, kp->kpemr);
301
302 return 0;
303 }
304
305
bcm_kp_probe(struct platform_device * pdev)306 static int bcm_kp_probe(struct platform_device *pdev)
307 {
308 struct bcm_kp *kp;
309 struct input_dev *input_dev;
310 int error;
311
312 kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);
313 if (!kp)
314 return -ENOMEM;
315
316 input_dev = devm_input_allocate_device(&pdev->dev);
317 if (!input_dev) {
318 dev_err(&pdev->dev, "failed to allocate the input device\n");
319 return -ENOMEM;
320 }
321
322 __set_bit(EV_KEY, input_dev->evbit);
323
324 /* Enable auto repeat feature of Linux input subsystem */
325 if (of_property_read_bool(pdev->dev.of_node, "autorepeat"))
326 __set_bit(EV_REP, input_dev->evbit);
327
328 input_dev->name = pdev->name;
329 input_dev->phys = "keypad/input0";
330 input_dev->dev.parent = &pdev->dev;
331 input_dev->open = bcm_kp_open;
332 input_dev->close = bcm_kp_close;
333
334 input_dev->id.bustype = BUS_HOST;
335 input_dev->id.vendor = 0x0001;
336 input_dev->id.product = 0x0001;
337 input_dev->id.version = 0x0100;
338
339 input_set_drvdata(input_dev, kp);
340
341 kp->input_dev = input_dev;
342
343 error = bcm_kp_matrix_key_parse_dt(kp);
344 if (error)
345 return error;
346
347 error = matrix_keypad_build_keymap(NULL, NULL,
348 kp->n_rows, kp->n_cols,
349 NULL, input_dev);
350 if (error) {
351 dev_err(&pdev->dev, "failed to build keymap\n");
352 return error;
353 }
354
355 kp->base = devm_platform_ioremap_resource(pdev, 0);
356 if (IS_ERR(kp->base))
357 return PTR_ERR(kp->base);
358
359 /* Enable clock */
360 kp->clk = devm_clk_get_optional(&pdev->dev, "peri_clk");
361 if (IS_ERR(kp->clk)) {
362 return dev_err_probe(&pdev->dev, PTR_ERR(kp->clk), "Failed to get clock\n");
363 } else if (!kp->clk) {
364 dev_dbg(&pdev->dev, "No clock specified. Assuming it's enabled\n");
365 } else {
366 unsigned int desired_rate;
367 long actual_rate;
368
369 error = of_property_read_u32(pdev->dev.of_node,
370 "clock-frequency", &desired_rate);
371 if (error < 0)
372 desired_rate = DEFAULT_CLK_HZ;
373
374 actual_rate = clk_round_rate(kp->clk, desired_rate);
375 if (actual_rate <= 0)
376 return -EINVAL;
377
378 error = clk_set_rate(kp->clk, actual_rate);
379 if (error)
380 return error;
381
382 error = clk_prepare_enable(kp->clk);
383 if (error)
384 return error;
385 }
386
387 /* Put the kp into a known sane state */
388 bcm_kp_stop(kp);
389
390 kp->irq = platform_get_irq(pdev, 0);
391 if (kp->irq < 0)
392 return -EINVAL;
393
394 error = devm_request_threaded_irq(&pdev->dev, kp->irq,
395 NULL, bcm_kp_isr_thread,
396 IRQF_ONESHOT, pdev->name, kp);
397 if (error) {
398 dev_err(&pdev->dev, "failed to request IRQ\n");
399 return error;
400 }
401
402 error = input_register_device(input_dev);
403 if (error) {
404 dev_err(&pdev->dev, "failed to register input device\n");
405 return error;
406 }
407
408 return 0;
409 }
410
411 static const struct of_device_id bcm_kp_of_match[] = {
412 { .compatible = "brcm,bcm-keypad" },
413 { },
414 };
415 MODULE_DEVICE_TABLE(of, bcm_kp_of_match);
416
417 static struct platform_driver bcm_kp_device_driver = {
418 .probe = bcm_kp_probe,
419 .driver = {
420 .name = "bcm-keypad",
421 .of_match_table = bcm_kp_of_match,
422 }
423 };
424
425 module_platform_driver(bcm_kp_device_driver);
426
427 MODULE_AUTHOR("Broadcom Corporation");
428 MODULE_DESCRIPTION("BCM Keypad Driver");
429 MODULE_LICENSE("GPL v2");
430