Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[linux-2.6-block.git] / drivers / input / keyboard / nspire-keypad.c
1 /*
2  *  Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2, as
6  * published by the Free Software Foundation.
7  */
8
9 #include <linux/input/matrix_keypad.h>
10 #include <linux/platform_device.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/delay.h>
14 #include <linux/input.h>
15 #include <linux/slab.h>
16 #include <linux/clk.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19
20 #define KEYPAD_SCAN_MODE        0x00
21 #define KEYPAD_CNTL             0x04
22 #define KEYPAD_INT              0x08
23 #define KEYPAD_INTMSK           0x0C
24
25 #define KEYPAD_DATA             0x10
26 #define KEYPAD_GPIO             0x30
27
28 #define KEYPAD_UNKNOWN_INT      0x40
29 #define KEYPAD_UNKNOWN_INT_STS  0x44
30
31 #define KEYPAD_BITMASK_COLS     11
32 #define KEYPAD_BITMASK_ROWS     8
33
34 struct nspire_keypad {
35         void __iomem *reg_base;
36         u32 int_mask;
37
38         struct input_dev *input;
39         struct clk *clk;
40
41         struct matrix_keymap_data *keymap;
42         int row_shift;
43
44         /* Maximum delay estimated assuming 33MHz APB */
45         u32 scan_interval;      /* In microseconds (~2000us max) */
46         u32 row_delay;          /* In microseconds (~500us max) */
47
48         u16 state[KEYPAD_BITMASK_ROWS];
49
50         bool active_low;
51 };
52
53 static irqreturn_t nspire_keypad_irq(int irq, void *dev_id)
54 {
55         struct nspire_keypad *keypad = dev_id;
56         struct input_dev *input = keypad->input;
57         unsigned short *keymap = input->keycode;
58         unsigned int code;
59         int row, col;
60         u32 int_sts;
61         u16 state[8];
62         u16 bits, changed;
63
64         int_sts = readl(keypad->reg_base + KEYPAD_INT) & keypad->int_mask;
65         if (!int_sts)
66                 return IRQ_NONE;
67
68         memcpy_fromio(state, keypad->reg_base + KEYPAD_DATA, sizeof(state));
69
70         for (row = 0; row < KEYPAD_BITMASK_ROWS; row++) {
71                 bits = state[row];
72                 if (keypad->active_low)
73                         bits = ~bits;
74
75                 changed = bits ^ keypad->state[row];
76                 if (!changed)
77                         continue;
78
79                 keypad->state[row] = bits;
80
81                 for (col = 0; col < KEYPAD_BITMASK_COLS; col++) {
82                         if (!(changed & (1U << col)))
83                                 continue;
84
85                         code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
86                         input_event(input, EV_MSC, MSC_SCAN, code);
87                         input_report_key(input, keymap[code],
88                                          bits & (1U << col));
89                 }
90         }
91
92         input_sync(input);
93
94         writel(0x3, keypad->reg_base + KEYPAD_INT);
95
96         return IRQ_HANDLED;
97 }
98
99 static int nspire_keypad_chip_init(struct nspire_keypad *keypad)
100 {
101         unsigned long val = 0, cycles_per_us, delay_cycles, row_delay_cycles;
102
103         cycles_per_us = (clk_get_rate(keypad->clk) / 1000000);
104         if (cycles_per_us == 0)
105                 cycles_per_us = 1;
106
107         delay_cycles = cycles_per_us * keypad->scan_interval;
108         WARN_ON(delay_cycles >= (1 << 16)); /* Overflow */
109         delay_cycles &= 0xffff;
110
111         row_delay_cycles = cycles_per_us * keypad->row_delay;
112         WARN_ON(row_delay_cycles >= (1 << 14)); /* Overflow */
113         row_delay_cycles &= 0x3fff;
114
115         val |= 3 << 0; /* Set scan mode to 3 (continuous scan) */
116         val |= row_delay_cycles << 2; /* Delay between scanning each row */
117         val |= delay_cycles << 16; /* Delay between scans */
118         writel(val, keypad->reg_base + KEYPAD_SCAN_MODE);
119
120         val = (KEYPAD_BITMASK_ROWS & 0xff) | (KEYPAD_BITMASK_COLS & 0xff)<<8;
121         writel(val, keypad->reg_base + KEYPAD_CNTL);
122
123         /* Enable interrupts */
124         keypad->int_mask = 1 << 1;
125         writel(keypad->int_mask, keypad->reg_base + KEYPAD_INTMSK);
126
127         /* Disable GPIO interrupts to prevent hanging on touchpad */
128         /* Possibly used to detect touchpad events */
129         writel(0, keypad->reg_base + KEYPAD_UNKNOWN_INT);
130         /* Acknowledge existing interrupts */
131         writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS);
132
133         return 0;
134 }
135
136 static int nspire_keypad_open(struct input_dev *input)
137 {
138         struct nspire_keypad *keypad = input_get_drvdata(input);
139         int error;
140
141         error = clk_prepare_enable(keypad->clk);
142         if (error)
143                 return error;
144
145         error = nspire_keypad_chip_init(keypad);
146         if (error) {
147                 clk_disable_unprepare(keypad->clk);
148                 return error;
149         }
150
151         return 0;
152 }
153
154 static void nspire_keypad_close(struct input_dev *input)
155 {
156         struct nspire_keypad *keypad = input_get_drvdata(input);
157
158         clk_disable_unprepare(keypad->clk);
159 }
160
161 static int nspire_keypad_probe(struct platform_device *pdev)
162 {
163         const struct device_node *of_node = pdev->dev.of_node;
164         struct nspire_keypad *keypad;
165         struct input_dev *input;
166         struct resource *res;
167         int irq;
168         int error;
169
170         irq = platform_get_irq(pdev, 0);
171         if (irq < 0) {
172                 dev_err(&pdev->dev, "failed to get keypad irq\n");
173                 return -EINVAL;
174         }
175
176         keypad = devm_kzalloc(&pdev->dev, sizeof(struct nspire_keypad),
177                               GFP_KERNEL);
178         if (!keypad) {
179                 dev_err(&pdev->dev, "failed to allocate keypad memory\n");
180                 return -ENOMEM;
181         }
182
183         keypad->row_shift = get_count_order(KEYPAD_BITMASK_COLS);
184
185         error = of_property_read_u32(of_node, "scan-interval",
186                                      &keypad->scan_interval);
187         if (error) {
188                 dev_err(&pdev->dev, "failed to get scan-interval\n");
189                 return error;
190         }
191
192         error = of_property_read_u32(of_node, "row-delay",
193                                      &keypad->row_delay);
194         if (error) {
195                 dev_err(&pdev->dev, "failed to get row-delay\n");
196                 return error;
197         }
198
199         keypad->active_low = of_property_read_bool(of_node, "active-low");
200
201         keypad->clk = devm_clk_get(&pdev->dev, NULL);
202         if (IS_ERR(keypad->clk)) {
203                 dev_err(&pdev->dev, "unable to get clock\n");
204                 return PTR_ERR(keypad->clk);
205         }
206
207         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
208         keypad->reg_base = devm_ioremap_resource(&pdev->dev, res);
209         if (IS_ERR(keypad->reg_base))
210                 return PTR_ERR(keypad->reg_base);
211
212         keypad->input = input = devm_input_allocate_device(&pdev->dev);
213         if (!input) {
214                 dev_err(&pdev->dev, "failed to allocate input device\n");
215                 return -ENOMEM;
216         }
217
218         input_set_drvdata(input, keypad);
219
220         input->id.bustype = BUS_HOST;
221         input->name = "nspire-keypad";
222         input->open = nspire_keypad_open;
223         input->close = nspire_keypad_close;
224
225         __set_bit(EV_KEY, input->evbit);
226         __set_bit(EV_REP, input->evbit);
227         input_set_capability(input, EV_MSC, MSC_SCAN);
228
229         error = matrix_keypad_build_keymap(NULL, NULL,
230                                            KEYPAD_BITMASK_ROWS,
231                                            KEYPAD_BITMASK_COLS,
232                                            NULL, input);
233         if (error) {
234                 dev_err(&pdev->dev, "building keymap failed\n");
235                 return error;
236         }
237
238         error = devm_request_irq(&pdev->dev, irq, nspire_keypad_irq, 0,
239                                  "nspire_keypad", keypad);
240         if (error) {
241                 dev_err(&pdev->dev, "allocate irq %d failed\n", irq);
242                 return error;
243         }
244
245         error = input_register_device(input);
246         if (error) {
247                 dev_err(&pdev->dev,
248                         "unable to register input device: %d\n", error);
249                 return error;
250         }
251
252         dev_dbg(&pdev->dev,
253                 "TI-NSPIRE keypad at %pR (scan_interval=%uus, row_delay=%uus%s)\n",
254                 res, keypad->row_delay, keypad->scan_interval,
255                 keypad->active_low ? ", active_low" : "");
256
257         return 0;
258 }
259
260 static const struct of_device_id nspire_keypad_dt_match[] = {
261         { .compatible = "ti,nspire-keypad" },
262         { },
263 };
264 MODULE_DEVICE_TABLE(of, nspire_keypad_dt_match);
265
266 static struct platform_driver nspire_keypad_driver = {
267         .driver = {
268                 .name = "nspire-keypad",
269                 .of_match_table = nspire_keypad_dt_match,
270         },
271         .probe = nspire_keypad_probe,
272 };
273
274 module_platform_driver(nspire_keypad_driver);
275
276 MODULE_LICENSE("GPL");
277 MODULE_DESCRIPTION("TI-NSPIRE Keypad Driver");