1 /*
2 * SPEAr Keyboard Driver
3 * Based on omap-keypad driver
4 *
5 * Copyright (C) 2010 ST Microelectronics
6 * Rajeev Kumar <rajeevkumar.linux@gmail.com>
7 *
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
11 */
12
13 #include <linux/clk.h>
14 #include <linux/errno.h>
15 #include <linux/interrupt.h>
16 #include <linux/input.h>
17 #include <linux/io.h>
18 #include <linux/irq.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/platform_device.h>
23 #include <linux/pm_wakeup.h>
24 #include <linux/slab.h>
25 #include <linux/types.h>
26 #include <linux/platform_data/keyboard-spear.h>
27
28 /* Keyboard Registers */
29 #define MODE_CTL_REG 0x00
30 #define STATUS_REG 0x0C
31 #define DATA_REG 0x10
32 #define INTR_MASK 0x54
33
34 /* Register Values */
35 #define NUM_ROWS 16
36 #define NUM_COLS 16
37 #define MODE_CTL_PCLK_FREQ_SHIFT 9
38 #define MODE_CTL_PCLK_FREQ_MSK 0x7F
39
40 #define MODE_CTL_KEYBOARD (0x2 << 0)
41 #define MODE_CTL_SCAN_RATE_10 (0x0 << 2)
42 #define MODE_CTL_SCAN_RATE_20 (0x1 << 2)
43 #define MODE_CTL_SCAN_RATE_40 (0x2 << 2)
44 #define MODE_CTL_SCAN_RATE_80 (0x3 << 2)
45 #define MODE_CTL_KEYNUM_SHIFT 6
46 #define MODE_CTL_START_SCAN (0x1 << 8)
47
48 #define STATUS_DATA_AVAIL (0x1 << 1)
49
50 #define DATA_ROW_MASK 0xF0
51 #define DATA_COLUMN_MASK 0x0F
52
53 #define ROW_SHIFT 4
54
55 struct spear_kbd {
56 struct input_dev *input;
57 void __iomem *io_base;
58 struct clk *clk;
59 unsigned int irq;
60 unsigned int mode;
61 unsigned int suspended_rate;
62 unsigned short last_key;
63 unsigned short keycodes[NUM_ROWS * NUM_COLS];
64 bool rep;
65 bool irq_wake_enabled;
66 u32 mode_ctl_reg;
67 };
68
spear_kbd_interrupt(int irq,void * dev_id)69 static irqreturn_t spear_kbd_interrupt(int irq, void *dev_id)
70 {
71 struct spear_kbd *kbd = dev_id;
72 struct input_dev *input = kbd->input;
73 unsigned int key;
74 u32 sts, val;
75
76 sts = readl_relaxed(kbd->io_base + STATUS_REG);
77 if (!(sts & STATUS_DATA_AVAIL))
78 return IRQ_NONE;
79
80 if (kbd->last_key != KEY_RESERVED) {
81 input_report_key(input, kbd->last_key, 0);
82 kbd->last_key = KEY_RESERVED;
83 }
84
85 /* following reads active (row, col) pair */
86 val = readl_relaxed(kbd->io_base + DATA_REG) &
87 (DATA_ROW_MASK | DATA_COLUMN_MASK);
88 key = kbd->keycodes[val];
89
90 input_event(input, EV_MSC, MSC_SCAN, val);
91 input_report_key(input, key, 1);
92 input_sync(input);
93
94 kbd->last_key = key;
95
96 /* clear interrupt */
97 writel_relaxed(0, kbd->io_base + STATUS_REG);
98
99 return IRQ_HANDLED;
100 }
101
spear_kbd_open(struct input_dev * dev)102 static int spear_kbd_open(struct input_dev *dev)
103 {
104 struct spear_kbd *kbd = input_get_drvdata(dev);
105 int error;
106 u32 val;
107
108 kbd->last_key = KEY_RESERVED;
109
110 error = clk_enable(kbd->clk);
111 if (error)
112 return error;
113
114 /* keyboard rate to be programmed is input clock (in MHz) - 1 */
115 val = clk_get_rate(kbd->clk) / 1000000 - 1;
116 val = (val & MODE_CTL_PCLK_FREQ_MSK) << MODE_CTL_PCLK_FREQ_SHIFT;
117
118 /* program keyboard */
119 val = MODE_CTL_SCAN_RATE_80 | MODE_CTL_KEYBOARD | val |
120 (kbd->mode << MODE_CTL_KEYNUM_SHIFT);
121 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
122 writel_relaxed(1, kbd->io_base + STATUS_REG);
123
124 /* start key scan */
125 val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
126 val |= MODE_CTL_START_SCAN;
127 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
128
129 return 0;
130 }
131
spear_kbd_close(struct input_dev * dev)132 static void spear_kbd_close(struct input_dev *dev)
133 {
134 struct spear_kbd *kbd = input_get_drvdata(dev);
135 u32 val;
136
137 /* stop key scan */
138 val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
139 val &= ~MODE_CTL_START_SCAN;
140 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
141
142 clk_disable(kbd->clk);
143
144 kbd->last_key = KEY_RESERVED;
145 }
146
147 #ifdef CONFIG_OF
spear_kbd_parse_dt(struct platform_device * pdev,struct spear_kbd * kbd)148 static int spear_kbd_parse_dt(struct platform_device *pdev,
149 struct spear_kbd *kbd)
150 {
151 struct device_node *np = pdev->dev.of_node;
152 int error;
153 u32 val, suspended_rate;
154
155 if (!np) {
156 dev_err(&pdev->dev, "Missing DT data\n");
157 return -EINVAL;
158 }
159
160 if (of_property_read_bool(np, "autorepeat"))
161 kbd->rep = true;
162
163 if (of_property_read_u32(np, "suspended_rate", &suspended_rate))
164 kbd->suspended_rate = suspended_rate;
165
166 error = of_property_read_u32(np, "st,mode", &val);
167 if (error) {
168 dev_err(&pdev->dev, "DT: Invalid or missing mode\n");
169 return error;
170 }
171
172 kbd->mode = val;
173 return 0;
174 }
175 #else
spear_kbd_parse_dt(struct platform_device * pdev,struct spear_kbd * kbd)176 static inline int spear_kbd_parse_dt(struct platform_device *pdev,
177 struct spear_kbd *kbd)
178 {
179 return -ENOSYS;
180 }
181 #endif
182
spear_kbd_probe(struct platform_device * pdev)183 static int spear_kbd_probe(struct platform_device *pdev)
184 {
185 struct kbd_platform_data *pdata = dev_get_platdata(&pdev->dev);
186 const struct matrix_keymap_data *keymap = pdata ? pdata->keymap : NULL;
187 struct spear_kbd *kbd;
188 struct input_dev *input_dev;
189 struct resource *res;
190 int irq;
191 int error;
192
193 irq = platform_get_irq(pdev, 0);
194 if (irq < 0)
195 return irq;
196
197 kbd = devm_kzalloc(&pdev->dev, sizeof(*kbd), GFP_KERNEL);
198 if (!kbd) {
199 dev_err(&pdev->dev, "not enough memory for driver data\n");
200 return -ENOMEM;
201 }
202
203 input_dev = devm_input_allocate_device(&pdev->dev);
204 if (!input_dev) {
205 dev_err(&pdev->dev, "unable to allocate input device\n");
206 return -ENOMEM;
207 }
208
209 kbd->input = input_dev;
210 kbd->irq = irq;
211
212 if (!pdata) {
213 error = spear_kbd_parse_dt(pdev, kbd);
214 if (error)
215 return error;
216 } else {
217 kbd->mode = pdata->mode;
218 kbd->rep = pdata->rep;
219 kbd->suspended_rate = pdata->suspended_rate;
220 }
221
222 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
223 kbd->io_base = devm_ioremap_resource(&pdev->dev, res);
224 if (IS_ERR(kbd->io_base))
225 return PTR_ERR(kbd->io_base);
226
227 kbd->clk = devm_clk_get(&pdev->dev, NULL);
228 if (IS_ERR(kbd->clk))
229 return PTR_ERR(kbd->clk);
230
231 input_dev->name = "Spear Keyboard";
232 input_dev->phys = "keyboard/input0";
233 input_dev->id.bustype = BUS_HOST;
234 input_dev->id.vendor = 0x0001;
235 input_dev->id.product = 0x0001;
236 input_dev->id.version = 0x0100;
237 input_dev->open = spear_kbd_open;
238 input_dev->close = spear_kbd_close;
239
240 error = matrix_keypad_build_keymap(keymap, NULL, NUM_ROWS, NUM_COLS,
241 kbd->keycodes, input_dev);
242 if (error) {
243 dev_err(&pdev->dev, "Failed to build keymap\n");
244 return error;
245 }
246
247 if (kbd->rep)
248 __set_bit(EV_REP, input_dev->evbit);
249 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
250
251 input_set_drvdata(input_dev, kbd);
252
253 error = devm_request_irq(&pdev->dev, irq, spear_kbd_interrupt, 0,
254 "keyboard", kbd);
255 if (error) {
256 dev_err(&pdev->dev, "request_irq failed\n");
257 return error;
258 }
259
260 error = clk_prepare(kbd->clk);
261 if (error)
262 return error;
263
264 error = input_register_device(input_dev);
265 if (error) {
266 dev_err(&pdev->dev, "Unable to register keyboard device\n");
267 clk_unprepare(kbd->clk);
268 return error;
269 }
270
271 device_init_wakeup(&pdev->dev, 1);
272 platform_set_drvdata(pdev, kbd);
273
274 return 0;
275 }
276
spear_kbd_remove(struct platform_device * pdev)277 static int spear_kbd_remove(struct platform_device *pdev)
278 {
279 struct spear_kbd *kbd = platform_get_drvdata(pdev);
280
281 input_unregister_device(kbd->input);
282 clk_unprepare(kbd->clk);
283
284 return 0;
285 }
286
spear_kbd_suspend(struct device * dev)287 static int __maybe_unused spear_kbd_suspend(struct device *dev)
288 {
289 struct platform_device *pdev = to_platform_device(dev);
290 struct spear_kbd *kbd = platform_get_drvdata(pdev);
291 struct input_dev *input_dev = kbd->input;
292 unsigned int rate = 0, mode_ctl_reg, val;
293
294 mutex_lock(&input_dev->mutex);
295
296 /* explicitly enable clock as we may program device */
297 clk_enable(kbd->clk);
298
299 mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
300
301 if (device_may_wakeup(&pdev->dev)) {
302 if (!enable_irq_wake(kbd->irq))
303 kbd->irq_wake_enabled = true;
304
305 /*
306 * reprogram the keyboard operating frequency as on some
307 * platform it may change during system suspended
308 */
309 if (kbd->suspended_rate)
310 rate = kbd->suspended_rate / 1000000 - 1;
311 else
312 rate = clk_get_rate(kbd->clk) / 1000000 - 1;
313
314 val = mode_ctl_reg &
315 ~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
316 val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
317 << MODE_CTL_PCLK_FREQ_SHIFT;
318 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
319
320 } else {
321 if (input_dev->users) {
322 writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
323 kbd->io_base + MODE_CTL_REG);
324 clk_disable(kbd->clk);
325 }
326 }
327
328 /* store current configuration */
329 if (input_dev->users)
330 kbd->mode_ctl_reg = mode_ctl_reg;
331
332 /* restore previous clk state */
333 clk_disable(kbd->clk);
334
335 mutex_unlock(&input_dev->mutex);
336
337 return 0;
338 }
339
spear_kbd_resume(struct device * dev)340 static int __maybe_unused spear_kbd_resume(struct device *dev)
341 {
342 struct platform_device *pdev = to_platform_device(dev);
343 struct spear_kbd *kbd = platform_get_drvdata(pdev);
344 struct input_dev *input_dev = kbd->input;
345
346 mutex_lock(&input_dev->mutex);
347
348 if (device_may_wakeup(&pdev->dev)) {
349 if (kbd->irq_wake_enabled) {
350 kbd->irq_wake_enabled = false;
351 disable_irq_wake(kbd->irq);
352 }
353 } else {
354 if (input_dev->users)
355 clk_enable(kbd->clk);
356 }
357
358 /* restore current configuration */
359 if (input_dev->users)
360 writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
361
362 mutex_unlock(&input_dev->mutex);
363
364 return 0;
365 }
366
367 static SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops, spear_kbd_suspend, spear_kbd_resume);
368
369 #ifdef CONFIG_OF
370 static const struct of_device_id spear_kbd_id_table[] = {
371 { .compatible = "st,spear300-kbd" },
372 {}
373 };
374 MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
375 #endif
376
377 static struct platform_driver spear_kbd_driver = {
378 .probe = spear_kbd_probe,
379 .remove = spear_kbd_remove,
380 .driver = {
381 .name = "keyboard",
382 .pm = &spear_kbd_pm_ops,
383 .of_match_table = of_match_ptr(spear_kbd_id_table),
384 },
385 };
386 module_platform_driver(spear_kbd_driver);
387
388 MODULE_AUTHOR("Rajeev Kumar");
389 MODULE_DESCRIPTION("SPEAr Keyboard Driver");
390 MODULE_LICENSE("GPL");
391
