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(addr: 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(dev: input, EV_MSC, MSC_SCAN, value: code); |
84 | input_report_key(dev: input, code: keymap[code], |
85 | value: bits & (1U << col)); |
86 | } |
87 | } |
88 | |
89 | input_sync(dev: input); |
90 | |
91 | writel(val: 0x3, addr: keypad->reg_base + KEYPAD_INT); |
92 | |
93 | return IRQ_HANDLED; |
94 | } |
95 | |
96 | static int nspire_keypad_open(struct input_dev *input) |
97 | { |
98 | struct nspire_keypad *keypad = input_get_drvdata(dev: input); |
99 | unsigned long val = 0, cycles_per_us, delay_cycles, row_delay_cycles; |
100 | int error; |
101 | |
102 | error = clk_prepare_enable(clk: keypad->clk); |
103 | if (error) |
104 | return error; |
105 | |
106 | cycles_per_us = (clk_get_rate(clk: keypad->clk) / 1000000); |
107 | if (cycles_per_us == 0) |
108 | cycles_per_us = 1; |
109 | |
110 | delay_cycles = cycles_per_us * keypad->scan_interval; |
111 | WARN_ON(delay_cycles >= (1 << 16)); /* Overflow */ |
112 | delay_cycles &= 0xffff; |
113 | |
114 | row_delay_cycles = cycles_per_us * keypad->row_delay; |
115 | WARN_ON(row_delay_cycles >= (1 << 14)); /* Overflow */ |
116 | row_delay_cycles &= 0x3fff; |
117 | |
118 | val |= 3 << 0; /* Set scan mode to 3 (continuous scan) */ |
119 | val |= row_delay_cycles << 2; /* Delay between scanning each row */ |
120 | val |= delay_cycles << 16; /* Delay between scans */ |
121 | writel(val, addr: keypad->reg_base + KEYPAD_SCAN_MODE); |
122 | |
123 | val = (KEYPAD_BITMASK_ROWS & 0xff) | (KEYPAD_BITMASK_COLS & 0xff)<<8; |
124 | writel(val, addr: keypad->reg_base + KEYPAD_CNTL); |
125 | |
126 | /* Enable interrupts */ |
127 | keypad->int_mask = 1 << 1; |
128 | writel(val: keypad->int_mask, addr: keypad->reg_base + KEYPAD_INTMSK); |
129 | |
130 | return 0; |
131 | } |
132 | |
133 | static void nspire_keypad_close(struct input_dev *input) |
134 | { |
135 | struct nspire_keypad *keypad = input_get_drvdata(dev: input); |
136 | |
137 | /* Disable interrupts */ |
138 | writel(val: 0, addr: keypad->reg_base + KEYPAD_INTMSK); |
139 | /* Acknowledge existing interrupts */ |
140 | writel(val: ~0, addr: keypad->reg_base + KEYPAD_INT); |
141 | |
142 | clk_disable_unprepare(clk: keypad->clk); |
143 | } |
144 | |
145 | static int nspire_keypad_probe(struct platform_device *pdev) |
146 | { |
147 | const struct device_node *of_node = pdev->dev.of_node; |
148 | struct nspire_keypad *keypad; |
149 | struct input_dev *input; |
150 | struct resource *res; |
151 | int irq; |
152 | int error; |
153 | |
154 | irq = platform_get_irq(pdev, 0); |
155 | if (irq < 0) |
156 | return -EINVAL; |
157 | |
158 | keypad = devm_kzalloc(dev: &pdev->dev, size: sizeof(struct nspire_keypad), |
159 | GFP_KERNEL); |
160 | if (!keypad) { |
161 | dev_err(&pdev->dev, "failed to allocate keypad memory\n" ); |
162 | return -ENOMEM; |
163 | } |
164 | |
165 | keypad->row_shift = get_count_order(KEYPAD_BITMASK_COLS); |
166 | |
167 | error = of_property_read_u32(np: of_node, propname: "scan-interval" , |
168 | out_value: &keypad->scan_interval); |
169 | if (error) { |
170 | dev_err(&pdev->dev, "failed to get scan-interval\n" ); |
171 | return error; |
172 | } |
173 | |
174 | error = of_property_read_u32(np: of_node, propname: "row-delay" , |
175 | out_value: &keypad->row_delay); |
176 | if (error) { |
177 | dev_err(&pdev->dev, "failed to get row-delay\n" ); |
178 | return error; |
179 | } |
180 | |
181 | keypad->active_low = of_property_read_bool(np: of_node, propname: "active-low" ); |
182 | |
183 | keypad->clk = devm_clk_get(dev: &pdev->dev, NULL); |
184 | if (IS_ERR(ptr: keypad->clk)) { |
185 | dev_err(&pdev->dev, "unable to get clock\n" ); |
186 | return PTR_ERR(ptr: keypad->clk); |
187 | } |
188 | |
189 | keypad->reg_base = devm_platform_get_and_ioremap_resource(pdev, index: 0, res: &res); |
190 | if (IS_ERR(ptr: keypad->reg_base)) |
191 | return PTR_ERR(ptr: keypad->reg_base); |
192 | |
193 | keypad->input = input = devm_input_allocate_device(&pdev->dev); |
194 | if (!input) { |
195 | dev_err(&pdev->dev, "failed to allocate input device\n" ); |
196 | return -ENOMEM; |
197 | } |
198 | |
199 | error = clk_prepare_enable(clk: keypad->clk); |
200 | if (error) { |
201 | dev_err(&pdev->dev, "failed to enable clock\n" ); |
202 | return error; |
203 | } |
204 | |
205 | /* Disable interrupts */ |
206 | writel(val: 0, addr: keypad->reg_base + KEYPAD_INTMSK); |
207 | /* Acknowledge existing interrupts */ |
208 | writel(val: ~0, addr: keypad->reg_base + KEYPAD_INT); |
209 | |
210 | /* Disable GPIO interrupts to prevent hanging on touchpad */ |
211 | /* Possibly used to detect touchpad events */ |
212 | writel(val: 0, addr: keypad->reg_base + KEYPAD_UNKNOWN_INT); |
213 | /* Acknowledge existing GPIO interrupts */ |
214 | writel(val: ~0, addr: keypad->reg_base + KEYPAD_UNKNOWN_INT_STS); |
215 | |
216 | clk_disable_unprepare(clk: keypad->clk); |
217 | |
218 | input_set_drvdata(dev: input, data: 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(dev: 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_dev: input); |
233 | if (error) { |
234 | dev_err(&pdev->dev, "building keymap failed\n" ); |
235 | return error; |
236 | } |
237 | |
238 | error = devm_request_irq(dev: &pdev->dev, irq, handler: nspire_keypad_irq, irqflags: 0, |
239 | devname: "nspire_keypad" , dev_id: 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" ); |
278 | |