Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-microblaze.git] / drivers / input / keyboard / nspire-keypad.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
4  */
5
6 #include <linux/input/matrix_keypad.h>
7 #include <linux/platform_device.h>
8 #include <linux/interrupt.h>
9 #include <linux/io.h>
10 #include <linux/delay.h>
11 #include <linux/input.h>
12 #include <linux/slab.h>
13 #include <linux/clk.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16
17 #define KEYPAD_SCAN_MODE        0x00
18 #define KEYPAD_CNTL             0x04
19 #define KEYPAD_INT              0x08
20 #define KEYPAD_INTMSK           0x0C
21
22 #define KEYPAD_DATA             0x10
23 #define KEYPAD_GPIO             0x30
24
25 #define KEYPAD_UNKNOWN_INT      0x40
26 #define KEYPAD_UNKNOWN_INT_STS  0x44
27
28 #define KEYPAD_BITMASK_COLS     11
29 #define KEYPAD_BITMASK_ROWS     8
30
31 struct nspire_keypad {
32         void __iomem *reg_base;
33         u32 int_mask;
34
35         struct input_dev *input;
36         struct clk *clk;
37
38         struct matrix_keymap_data *keymap;
39         int row_shift;
40
41         /* Maximum delay estimated assuming 33MHz APB */
42         u32 scan_interval;      /* In microseconds (~2000us max) */
43         u32 row_delay;          /* In microseconds (~500us max) */
44
45         u16 state[KEYPAD_BITMASK_ROWS];
46
47         bool active_low;
48 };
49
50 static irqreturn_t nspire_keypad_irq(int irq, void *dev_id)
51 {
52         struct nspire_keypad *keypad = dev_id;
53         struct input_dev *input = keypad->input;
54         unsigned short *keymap = input->keycode;
55         unsigned int code;
56         int row, col;
57         u32 int_sts;
58         u16 state[8];
59         u16 bits, changed;
60
61         int_sts = readl(keypad->reg_base + KEYPAD_INT) & keypad->int_mask;
62         if (!int_sts)
63                 return IRQ_NONE;
64
65         memcpy_fromio(state, keypad->reg_base + KEYPAD_DATA, sizeof(state));
66
67         for (row = 0; row < KEYPAD_BITMASK_ROWS; row++) {
68                 bits = state[row];
69                 if (keypad->active_low)
70                         bits = ~bits;
71
72                 changed = bits ^ keypad->state[row];
73                 if (!changed)
74                         continue;
75
76                 keypad->state[row] = bits;
77
78                 for (col = 0; col < KEYPAD_BITMASK_COLS; col++) {
79                         if (!(changed & (1U << col)))
80                                 continue;
81
82                         code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
83                         input_event(input, EV_MSC, MSC_SCAN, code);
84                         input_report_key(input, keymap[code],
85                                          bits & (1U << col));
86                 }
87         }
88
89         input_sync(input);
90
91         writel(0x3, keypad->reg_base + KEYPAD_INT);
92
93         return IRQ_HANDLED;
94 }
95
96 static int nspire_keypad_chip_init(struct nspire_keypad *keypad)
97 {
98         unsigned long val = 0, cycles_per_us, delay_cycles, row_delay_cycles;
99
100         cycles_per_us = (clk_get_rate(keypad->clk) / 1000000);
101         if (cycles_per_us == 0)
102                 cycles_per_us = 1;
103
104         delay_cycles = cycles_per_us * keypad->scan_interval;
105         WARN_ON(delay_cycles >= (1 << 16)); /* Overflow */
106         delay_cycles &= 0xffff;
107
108         row_delay_cycles = cycles_per_us * keypad->row_delay;
109         WARN_ON(row_delay_cycles >= (1 << 14)); /* Overflow */
110         row_delay_cycles &= 0x3fff;
111
112         val |= 3 << 0; /* Set scan mode to 3 (continuous scan) */
113         val |= row_delay_cycles << 2; /* Delay between scanning each row */
114         val |= delay_cycles << 16; /* Delay between scans */
115         writel(val, keypad->reg_base + KEYPAD_SCAN_MODE);
116
117         val = (KEYPAD_BITMASK_ROWS & 0xff) | (KEYPAD_BITMASK_COLS & 0xff)<<8;
118         writel(val, keypad->reg_base + KEYPAD_CNTL);
119
120         /* Enable interrupts */
121         keypad->int_mask = 1 << 1;
122         writel(keypad->int_mask, keypad->reg_base + KEYPAD_INTMSK);
123
124         /* Disable GPIO interrupts to prevent hanging on touchpad */
125         /* Possibly used to detect touchpad events */
126         writel(0, keypad->reg_base + KEYPAD_UNKNOWN_INT);
127         /* Acknowledge existing interrupts */
128         writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS);
129
130         return 0;
131 }
132
133 static int nspire_keypad_open(struct input_dev *input)
134 {
135         struct nspire_keypad *keypad = input_get_drvdata(input);
136         int error;
137
138         error = clk_prepare_enable(keypad->clk);
139         if (error)
140                 return error;
141
142         error = nspire_keypad_chip_init(keypad);
143         if (error) {
144                 clk_disable_unprepare(keypad->clk);
145                 return error;
146         }
147
148         return 0;
149 }
150
151 static void nspire_keypad_close(struct input_dev *input)
152 {
153         struct nspire_keypad *keypad = input_get_drvdata(input);
154
155         clk_disable_unprepare(keypad->clk);
156 }
157
158 static int nspire_keypad_probe(struct platform_device *pdev)
159 {
160         const struct device_node *of_node = pdev->dev.of_node;
161         struct nspire_keypad *keypad;
162         struct input_dev *input;
163         struct resource *res;
164         int irq;
165         int error;
166
167         irq = platform_get_irq(pdev, 0);
168         if (irq < 0) {
169                 dev_err(&pdev->dev, "failed to get keypad irq\n");
170                 return -EINVAL;
171         }
172
173         keypad = devm_kzalloc(&pdev->dev, sizeof(struct nspire_keypad),
174                               GFP_KERNEL);
175         if (!keypad) {
176                 dev_err(&pdev->dev, "failed to allocate keypad memory\n");
177                 return -ENOMEM;
178         }
179
180         keypad->row_shift = get_count_order(KEYPAD_BITMASK_COLS);
181
182         error = of_property_read_u32(of_node, "scan-interval",
183                                      &keypad->scan_interval);
184         if (error) {
185                 dev_err(&pdev->dev, "failed to get scan-interval\n");
186                 return error;
187         }
188
189         error = of_property_read_u32(of_node, "row-delay",
190                                      &keypad->row_delay);
191         if (error) {
192                 dev_err(&pdev->dev, "failed to get row-delay\n");
193                 return error;
194         }
195
196         keypad->active_low = of_property_read_bool(of_node, "active-low");
197
198         keypad->clk = devm_clk_get(&pdev->dev, NULL);
199         if (IS_ERR(keypad->clk)) {
200                 dev_err(&pdev->dev, "unable to get clock\n");
201                 return PTR_ERR(keypad->clk);
202         }
203
204         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
205         keypad->reg_base = devm_ioremap_resource(&pdev->dev, res);
206         if (IS_ERR(keypad->reg_base))
207                 return PTR_ERR(keypad->reg_base);
208
209         keypad->input = input = devm_input_allocate_device(&pdev->dev);
210         if (!input) {
211                 dev_err(&pdev->dev, "failed to allocate input device\n");
212                 return -ENOMEM;
213         }
214
215         input_set_drvdata(input, keypad);
216
217         input->id.bustype = BUS_HOST;
218         input->name = "nspire-keypad";
219         input->open = nspire_keypad_open;
220         input->close = nspire_keypad_close;
221
222         __set_bit(EV_KEY, input->evbit);
223         __set_bit(EV_REP, input->evbit);
224         input_set_capability(input, EV_MSC, MSC_SCAN);
225
226         error = matrix_keypad_build_keymap(NULL, NULL,
227                                            KEYPAD_BITMASK_ROWS,
228                                            KEYPAD_BITMASK_COLS,
229                                            NULL, input);
230         if (error) {
231                 dev_err(&pdev->dev, "building keymap failed\n");
232                 return error;
233         }
234
235         error = devm_request_irq(&pdev->dev, irq, nspire_keypad_irq, 0,
236                                  "nspire_keypad", keypad);
237         if (error) {
238                 dev_err(&pdev->dev, "allocate irq %d failed\n", irq);
239                 return error;
240         }
241
242         error = input_register_device(input);
243         if (error) {
244                 dev_err(&pdev->dev,
245                         "unable to register input device: %d\n", error);
246                 return error;
247         }
248
249         dev_dbg(&pdev->dev,
250                 "TI-NSPIRE keypad at %pR (scan_interval=%uus, row_delay=%uus%s)\n",
251                 res, keypad->row_delay, keypad->scan_interval,
252                 keypad->active_low ? ", active_low" : "");
253
254         return 0;
255 }
256
257 static const struct of_device_id nspire_keypad_dt_match[] = {
258         { .compatible = "ti,nspire-keypad" },
259         { },
260 };
261 MODULE_DEVICE_TABLE(of, nspire_keypad_dt_match);
262
263 static struct platform_driver nspire_keypad_driver = {
264         .driver = {
265                 .name = "nspire-keypad",
266                 .of_match_table = nspire_keypad_dt_match,
267         },
268         .probe = nspire_keypad_probe,
269 };
270
271 module_platform_driver(nspire_keypad_driver);
272
273 MODULE_LICENSE("GPL");
274 MODULE_DESCRIPTION("TI-NSPIRE Keypad Driver");