1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * STMicroelectronics Key Scanning driver |
4 | * |
5 | * Copyright (c) 2014 STMicroelectonics Ltd. |
6 | * Author: Stuart Menefy <stuart.menefy@st.com> |
7 | * |
8 | * Based on sh_keysc.c, copyright 2008 Magnus Damm |
9 | */ |
10 | |
11 | #include <linux/clk.h> |
12 | #include <linux/input.h> |
13 | #include <linux/input/matrix_keypad.h> |
14 | #include <linux/io.h> |
15 | #include <linux/interrupt.h> |
16 | #include <linux/module.h> |
17 | #include <linux/of.h> |
18 | #include <linux/platform_device.h> |
19 | |
20 | #define ST_KEYSCAN_MAXKEYS 16 |
21 | |
22 | #define KEYSCAN_CONFIG_OFF 0x0 |
23 | #define KEYSCAN_CONFIG_ENABLE 0x1 |
24 | #define KEYSCAN_DEBOUNCE_TIME_OFF 0x4 |
25 | #define KEYSCAN_MATRIX_STATE_OFF 0x8 |
26 | #define KEYSCAN_MATRIX_DIM_OFF 0xc |
27 | #define KEYSCAN_MATRIX_DIM_X_SHIFT 0x0 |
28 | #define KEYSCAN_MATRIX_DIM_Y_SHIFT 0x2 |
29 | |
30 | struct st_keyscan { |
31 | void __iomem *base; |
32 | int irq; |
33 | struct clk *clk; |
34 | struct input_dev *input_dev; |
35 | unsigned long last_state; |
36 | unsigned int n_rows; |
37 | unsigned int n_cols; |
38 | unsigned int debounce_us; |
39 | }; |
40 | |
41 | static irqreturn_t keyscan_isr(int irq, void *dev_id) |
42 | { |
43 | struct st_keyscan *keypad = dev_id; |
44 | unsigned short *keycode = keypad->input_dev->keycode; |
45 | unsigned long state, change; |
46 | int bit_nr; |
47 | |
48 | state = readl(addr: keypad->base + KEYSCAN_MATRIX_STATE_OFF) & 0xffff; |
49 | change = keypad->last_state ^ state; |
50 | keypad->last_state = state; |
51 | |
52 | for_each_set_bit(bit_nr, &change, BITS_PER_LONG) |
53 | input_report_key(dev: keypad->input_dev, |
54 | code: keycode[bit_nr], value: state & BIT(bit_nr)); |
55 | |
56 | input_sync(dev: keypad->input_dev); |
57 | |
58 | return IRQ_HANDLED; |
59 | } |
60 | |
61 | static int keyscan_start(struct st_keyscan *keypad) |
62 | { |
63 | int error; |
64 | |
65 | error = clk_enable(clk: keypad->clk); |
66 | if (error) |
67 | return error; |
68 | |
69 | writel(val: keypad->debounce_us * (clk_get_rate(clk: keypad->clk) / 1000000), |
70 | addr: keypad->base + KEYSCAN_DEBOUNCE_TIME_OFF); |
71 | |
72 | writel(val: ((keypad->n_cols - 1) << KEYSCAN_MATRIX_DIM_X_SHIFT) | |
73 | ((keypad->n_rows - 1) << KEYSCAN_MATRIX_DIM_Y_SHIFT), |
74 | addr: keypad->base + KEYSCAN_MATRIX_DIM_OFF); |
75 | |
76 | writel(KEYSCAN_CONFIG_ENABLE, addr: keypad->base + KEYSCAN_CONFIG_OFF); |
77 | |
78 | return 0; |
79 | } |
80 | |
81 | static void keyscan_stop(struct st_keyscan *keypad) |
82 | { |
83 | writel(val: 0, addr: keypad->base + KEYSCAN_CONFIG_OFF); |
84 | |
85 | clk_disable(clk: keypad->clk); |
86 | } |
87 | |
88 | static int keyscan_open(struct input_dev *dev) |
89 | { |
90 | struct st_keyscan *keypad = input_get_drvdata(dev); |
91 | |
92 | return keyscan_start(keypad); |
93 | } |
94 | |
95 | static void keyscan_close(struct input_dev *dev) |
96 | { |
97 | struct st_keyscan *keypad = input_get_drvdata(dev); |
98 | |
99 | keyscan_stop(keypad); |
100 | } |
101 | |
102 | static int keypad_matrix_key_parse_dt(struct st_keyscan *keypad_data) |
103 | { |
104 | struct device *dev = keypad_data->input_dev->dev.parent; |
105 | struct device_node *np = dev->of_node; |
106 | int error; |
107 | |
108 | error = matrix_keypad_parse_properties(dev, rows: &keypad_data->n_rows, |
109 | cols: &keypad_data->n_cols); |
110 | if (error) { |
111 | dev_err(dev, "failed to parse keypad params\n" ); |
112 | return error; |
113 | } |
114 | |
115 | of_property_read_u32(np, propname: "st,debounce-us" , out_value: &keypad_data->debounce_us); |
116 | |
117 | dev_dbg(dev, "n_rows=%d n_col=%d debounce=%d\n" , |
118 | keypad_data->n_rows, keypad_data->n_cols, |
119 | keypad_data->debounce_us); |
120 | |
121 | return 0; |
122 | } |
123 | |
124 | static int keyscan_probe(struct platform_device *pdev) |
125 | { |
126 | struct st_keyscan *keypad_data; |
127 | struct input_dev *input_dev; |
128 | int error; |
129 | |
130 | if (!pdev->dev.of_node) { |
131 | dev_err(&pdev->dev, "no DT data present\n" ); |
132 | return -EINVAL; |
133 | } |
134 | |
135 | keypad_data = devm_kzalloc(dev: &pdev->dev, size: sizeof(*keypad_data), |
136 | GFP_KERNEL); |
137 | if (!keypad_data) |
138 | return -ENOMEM; |
139 | |
140 | input_dev = devm_input_allocate_device(&pdev->dev); |
141 | if (!input_dev) { |
142 | dev_err(&pdev->dev, "failed to allocate the input device\n" ); |
143 | return -ENOMEM; |
144 | } |
145 | |
146 | input_dev->name = pdev->name; |
147 | input_dev->phys = "keyscan-keys/input0" ; |
148 | input_dev->dev.parent = &pdev->dev; |
149 | input_dev->open = keyscan_open; |
150 | input_dev->close = keyscan_close; |
151 | |
152 | input_dev->id.bustype = BUS_HOST; |
153 | |
154 | keypad_data->input_dev = input_dev; |
155 | |
156 | error = keypad_matrix_key_parse_dt(keypad_data); |
157 | if (error) |
158 | return error; |
159 | |
160 | error = matrix_keypad_build_keymap(NULL, NULL, |
161 | rows: keypad_data->n_rows, |
162 | cols: keypad_data->n_cols, |
163 | NULL, input_dev); |
164 | if (error) { |
165 | dev_err(&pdev->dev, "failed to build keymap\n" ); |
166 | return error; |
167 | } |
168 | |
169 | input_set_drvdata(dev: input_dev, data: keypad_data); |
170 | |
171 | keypad_data->base = devm_platform_get_and_ioremap_resource(pdev, index: 0, NULL); |
172 | if (IS_ERR(ptr: keypad_data->base)) |
173 | return PTR_ERR(ptr: keypad_data->base); |
174 | |
175 | keypad_data->clk = devm_clk_get(dev: &pdev->dev, NULL); |
176 | if (IS_ERR(ptr: keypad_data->clk)) { |
177 | dev_err(&pdev->dev, "cannot get clock\n" ); |
178 | return PTR_ERR(ptr: keypad_data->clk); |
179 | } |
180 | |
181 | error = clk_enable(clk: keypad_data->clk); |
182 | if (error) { |
183 | dev_err(&pdev->dev, "failed to enable clock\n" ); |
184 | return error; |
185 | } |
186 | |
187 | keyscan_stop(keypad: keypad_data); |
188 | |
189 | keypad_data->irq = platform_get_irq(pdev, 0); |
190 | if (keypad_data->irq < 0) |
191 | return -EINVAL; |
192 | |
193 | error = devm_request_irq(dev: &pdev->dev, irq: keypad_data->irq, handler: keyscan_isr, irqflags: 0, |
194 | devname: pdev->name, dev_id: keypad_data); |
195 | if (error) { |
196 | dev_err(&pdev->dev, "failed to request IRQ\n" ); |
197 | return error; |
198 | } |
199 | |
200 | error = input_register_device(input_dev); |
201 | if (error) { |
202 | dev_err(&pdev->dev, "failed to register input device\n" ); |
203 | return error; |
204 | } |
205 | |
206 | platform_set_drvdata(pdev, data: keypad_data); |
207 | |
208 | device_set_wakeup_capable(dev: &pdev->dev, capable: 1); |
209 | |
210 | return 0; |
211 | } |
212 | |
213 | static int keyscan_suspend(struct device *dev) |
214 | { |
215 | struct platform_device *pdev = to_platform_device(dev); |
216 | struct st_keyscan *keypad = platform_get_drvdata(pdev); |
217 | struct input_dev *input = keypad->input_dev; |
218 | |
219 | mutex_lock(&input->mutex); |
220 | |
221 | if (device_may_wakeup(dev)) |
222 | enable_irq_wake(irq: keypad->irq); |
223 | else if (input_device_enabled(dev: input)) |
224 | keyscan_stop(keypad); |
225 | |
226 | mutex_unlock(lock: &input->mutex); |
227 | return 0; |
228 | } |
229 | |
230 | static int keyscan_resume(struct device *dev) |
231 | { |
232 | struct platform_device *pdev = to_platform_device(dev); |
233 | struct st_keyscan *keypad = platform_get_drvdata(pdev); |
234 | struct input_dev *input = keypad->input_dev; |
235 | int retval = 0; |
236 | |
237 | mutex_lock(&input->mutex); |
238 | |
239 | if (device_may_wakeup(dev)) |
240 | disable_irq_wake(irq: keypad->irq); |
241 | else if (input_device_enabled(dev: input)) |
242 | retval = keyscan_start(keypad); |
243 | |
244 | mutex_unlock(lock: &input->mutex); |
245 | return retval; |
246 | } |
247 | |
248 | static DEFINE_SIMPLE_DEV_PM_OPS(keyscan_dev_pm_ops, |
249 | keyscan_suspend, keyscan_resume); |
250 | |
251 | static const struct of_device_id keyscan_of_match[] = { |
252 | { .compatible = "st,sti-keyscan" }, |
253 | { }, |
254 | }; |
255 | MODULE_DEVICE_TABLE(of, keyscan_of_match); |
256 | |
257 | static struct platform_driver keyscan_device_driver = { |
258 | .probe = keyscan_probe, |
259 | .driver = { |
260 | .name = "st-keyscan" , |
261 | .pm = pm_sleep_ptr(&keyscan_dev_pm_ops), |
262 | .of_match_table = keyscan_of_match, |
263 | } |
264 | }; |
265 | |
266 | module_platform_driver(keyscan_device_driver); |
267 | |
268 | MODULE_AUTHOR("Stuart Menefy <stuart.menefy@st.com>" ); |
269 | MODULE_DESCRIPTION("STMicroelectronics keyscan device driver" ); |
270 | MODULE_LICENSE("GPL" ); |
271 | |