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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
31struct 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
42 u32 scan_interval;
43 u32 row_delay;
44
45 u16 state[KEYPAD_BITMASK_ROWS];
46
47 bool active_low;
48};
49
50static 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
96static 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));
106 delay_cycles &= 0xffff;
107
108 row_delay_cycles = cycles_per_us * keypad->row_delay;
109 WARN_ON(row_delay_cycles >= (1 << 14));
110 row_delay_cycles &= 0x3fff;
111
112 val |= 3 << 0;
113 val |= row_delay_cycles << 2;
114 val |= delay_cycles << 16;
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
121 keypad->int_mask = 1 << 1;
122 writel(keypad->int_mask, keypad->reg_base + KEYPAD_INTMSK);
123
124
125
126 writel(0, keypad->reg_base + KEYPAD_UNKNOWN_INT);
127
128 writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS);
129
130 return 0;
131}
132
133static 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
151static 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
158static 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 return -EINVAL;
170
171 keypad = devm_kzalloc(&pdev->dev, sizeof(struct nspire_keypad),
172 GFP_KERNEL);
173 if (!keypad) {
174 dev_err(&pdev->dev, "failed to allocate keypad memory\n");
175 return -ENOMEM;
176 }
177
178 keypad->row_shift = get_count_order(KEYPAD_BITMASK_COLS);
179
180 error = of_property_read_u32(of_node, "scan-interval",
181 &keypad->scan_interval);
182 if (error) {
183 dev_err(&pdev->dev, "failed to get scan-interval\n");
184 return error;
185 }
186
187 error = of_property_read_u32(of_node, "row-delay",
188 &keypad->row_delay);
189 if (error) {
190 dev_err(&pdev->dev, "failed to get row-delay\n");
191 return error;
192 }
193
194 keypad->active_low = of_property_read_bool(of_node, "active-low");
195
196 keypad->clk = devm_clk_get(&pdev->dev, NULL);
197 if (IS_ERR(keypad->clk)) {
198 dev_err(&pdev->dev, "unable to get clock\n");
199 return PTR_ERR(keypad->clk);
200 }
201
202 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
203 keypad->reg_base = devm_ioremap_resource(&pdev->dev, res);
204 if (IS_ERR(keypad->reg_base))
205 return PTR_ERR(keypad->reg_base);
206
207 keypad->input = input = devm_input_allocate_device(&pdev->dev);
208 if (!input) {
209 dev_err(&pdev->dev, "failed to allocate input device\n");
210 return -ENOMEM;
211 }
212
213 input_set_drvdata(input, keypad);
214
215 input->id.bustype = BUS_HOST;
216 input->name = "nspire-keypad";
217 input->open = nspire_keypad_open;
218 input->close = nspire_keypad_close;
219
220 __set_bit(EV_KEY, input->evbit);
221 __set_bit(EV_REP, input->evbit);
222 input_set_capability(input, EV_MSC, MSC_SCAN);
223
224 error = matrix_keypad_build_keymap(NULL, NULL,
225 KEYPAD_BITMASK_ROWS,
226 KEYPAD_BITMASK_COLS,
227 NULL, input);
228 if (error) {
229 dev_err(&pdev->dev, "building keymap failed\n");
230 return error;
231 }
232
233 error = devm_request_irq(&pdev->dev, irq, nspire_keypad_irq, 0,
234 "nspire_keypad", keypad);
235 if (error) {
236 dev_err(&pdev->dev, "allocate irq %d failed\n", irq);
237 return error;
238 }
239
240 error = input_register_device(input);
241 if (error) {
242 dev_err(&pdev->dev,
243 "unable to register input device: %d\n", error);
244 return error;
245 }
246
247 dev_dbg(&pdev->dev,
248 "TI-NSPIRE keypad at %pR (scan_interval=%uus, row_delay=%uus%s)\n",
249 res, keypad->row_delay, keypad->scan_interval,
250 keypad->active_low ? ", active_low" : "");
251
252 return 0;
253}
254
255static const struct of_device_id nspire_keypad_dt_match[] = {
256 { .compatible = "ti,nspire-keypad" },
257 { },
258};
259MODULE_DEVICE_TABLE(of, nspire_keypad_dt_match);
260
261static struct platform_driver nspire_keypad_driver = {
262 .driver = {
263 .name = "nspire-keypad",
264 .of_match_table = nspire_keypad_dt_match,
265 },
266 .probe = nspire_keypad_probe,
267};
268
269module_platform_driver(nspire_keypad_driver);
270
271MODULE_LICENSE("GPL");
272MODULE_DESCRIPTION("TI-NSPIRE Keypad Driver");
273
