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/slab.h>
24 #include <linux/types.h>
25 #include <linux/platform_data/keyboard-spear.h>
26
27 /* Keyboard Registers */
28 #define MODE_CTL_REG 0x00
29 #define STATUS_REG 0x0C
30 #define DATA_REG 0x10
31 #define INTR_MASK 0x54
32
33 /* Register Values */
34 #define NUM_ROWS 16
35 #define NUM_COLS 16
36 #define MODE_CTL_PCLK_FREQ_SHIFT 9
37 #define MODE_CTL_PCLK_FREQ_MSK 0x7F
38
39 #define MODE_CTL_KEYBOARD (0x2 << 0)
40 #define MODE_CTL_SCAN_RATE_10 (0x0 << 2)
41 #define MODE_CTL_SCAN_RATE_20 (0x1 << 2)
42 #define MODE_CTL_SCAN_RATE_40 (0x2 << 2)
43 #define MODE_CTL_SCAN_RATE_80 (0x3 << 2)
44 #define MODE_CTL_KEYNUM_SHIFT 6
45 #define MODE_CTL_START_SCAN (0x1 << 8)
46
47 #define STATUS_DATA_AVAIL (0x1 << 1)
48
49 #define DATA_ROW_MASK 0xF0
50 #define DATA_COLUMN_MASK 0x0F
51
52 #define ROW_SHIFT 4
53
54 struct spear_kbd {
55 struct input_dev *input;
56 void __iomem *io_base;
57 struct clk *clk;
58 unsigned int irq;
59 unsigned int mode;
60 unsigned int suspended_rate;
61 unsigned short last_key;
62 unsigned short keycodes[NUM_ROWS * NUM_COLS];
63 bool rep;
64 bool irq_wake_enabled;
65 u32 mode_ctl_reg;
66 };
67
spear_kbd_interrupt(int irq,void * dev_id)68 static irqreturn_t spear_kbd_interrupt(int irq, void *dev_id)
69 {
70 struct spear_kbd *kbd = dev_id;
71 struct input_dev *input = kbd->input;
72 unsigned int key;
73 u32 sts, val;
74
75 sts = readl_relaxed(kbd->io_base + STATUS_REG);
76 if (!(sts & STATUS_DATA_AVAIL))
77 return IRQ_NONE;
78
79 if (kbd->last_key != KEY_RESERVED) {
80 input_report_key(input, kbd->last_key, 0);
81 kbd->last_key = KEY_RESERVED;
82 }
83
84 /* following reads active (row, col) pair */
85 val = readl_relaxed(kbd->io_base + DATA_REG) &
86 (DATA_ROW_MASK | DATA_COLUMN_MASK);
87 key = kbd->keycodes[val];
88
89 input_event(input, EV_MSC, MSC_SCAN, val);
90 input_report_key(input, key, 1);
91 input_sync(input);
92
93 kbd->last_key = key;
94
95 /* clear interrupt */
96 writel_relaxed(0, kbd->io_base + STATUS_REG);
97
98 return IRQ_HANDLED;
99 }
100
spear_kbd_open(struct input_dev * dev)101 static int spear_kbd_open(struct input_dev *dev)
102 {
103 struct spear_kbd *kbd = input_get_drvdata(dev);
104 int error;
105 u32 val;
106
107 kbd->last_key = KEY_RESERVED;
108
109 error = clk_enable(kbd->clk);
110 if (error)
111 return error;
112
113 /* keyboard rate to be programmed is input clock (in MHz) - 1 */
114 val = clk_get_rate(kbd->clk) / 1000000 - 1;
115 val = (val & MODE_CTL_PCLK_FREQ_MSK) << MODE_CTL_PCLK_FREQ_SHIFT;
116
117 /* program keyboard */
118 val = MODE_CTL_SCAN_RATE_80 | MODE_CTL_KEYBOARD | val |
119 (kbd->mode << MODE_CTL_KEYNUM_SHIFT);
120 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
121 writel_relaxed(1, kbd->io_base + STATUS_REG);
122
123 /* start key scan */
124 val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
125 val |= MODE_CTL_START_SCAN;
126 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
127
128 return 0;
129 }
130
spear_kbd_close(struct input_dev * dev)131 static void spear_kbd_close(struct input_dev *dev)
132 {
133 struct spear_kbd *kbd = input_get_drvdata(dev);
134 u32 val;
135
136 /* stop key scan */
137 val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
138 val &= ~MODE_CTL_START_SCAN;
139 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
140
141 clk_disable(kbd->clk);
142
143 kbd->last_key = KEY_RESERVED;
144 }
145
146 #ifdef CONFIG_OF
spear_kbd_parse_dt(struct platform_device * pdev,struct spear_kbd * kbd)147 static int spear_kbd_parse_dt(struct platform_device *pdev,
148 struct spear_kbd *kbd)
149 {
150 struct device_node *np = pdev->dev.of_node;
151 int error;
152 u32 val, suspended_rate;
153
154 if (!np) {
155 dev_err(&pdev->dev, "Missing DT data\n");
156 return -EINVAL;
157 }
158
159 if (of_property_read_bool(np, "autorepeat"))
160 kbd->rep = true;
161
162 if (of_property_read_u32(np, "suspended_rate", &suspended_rate))
163 kbd->suspended_rate = suspended_rate;
164
165 error = of_property_read_u32(np, "st,mode", &val);
166 if (error) {
167 dev_err(&pdev->dev, "DT: Invalid or missing mode\n");
168 return error;
169 }
170
171 kbd->mode = val;
172 return 0;
173 }
174 #else
spear_kbd_parse_dt(struct platform_device * pdev,struct spear_kbd * kbd)175 static inline int spear_kbd_parse_dt(struct platform_device *pdev,
176 struct spear_kbd *kbd)
177 {
178 return -ENOSYS;
179 }
180 #endif
181
spear_kbd_probe(struct platform_device * pdev)182 static int spear_kbd_probe(struct platform_device *pdev)
183 {
184 struct kbd_platform_data *pdata = dev_get_platdata(&pdev->dev);
185 const struct matrix_keymap_data *keymap = pdata ? pdata->keymap : NULL;
186 struct spear_kbd *kbd;
187 struct input_dev *input_dev;
188 int irq;
189 int error;
190
191 irq = platform_get_irq(pdev, 0);
192 if (irq < 0)
193 return irq;
194
195 kbd = devm_kzalloc(&pdev->dev, sizeof(*kbd), GFP_KERNEL);
196 if (!kbd) {
197 dev_err(&pdev->dev, "not enough memory for driver data\n");
198 return -ENOMEM;
199 }
200
201 input_dev = devm_input_allocate_device(&pdev->dev);
202 if (!input_dev) {
203 dev_err(&pdev->dev, "unable to allocate input device\n");
204 return -ENOMEM;
205 }
206
207 kbd->input = input_dev;
208 kbd->irq = irq;
209
210 if (!pdata) {
211 error = spear_kbd_parse_dt(pdev, kbd);
212 if (error)
213 return error;
214 } else {
215 kbd->mode = pdata->mode;
216 kbd->rep = pdata->rep;
217 kbd->suspended_rate = pdata->suspended_rate;
218 }
219
220 kbd->io_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
221 if (IS_ERR(kbd->io_base))
222 return PTR_ERR(kbd->io_base);
223
224 kbd->clk = devm_clk_get_prepared(&pdev->dev, NULL);
225 if (IS_ERR(kbd->clk))
226 return PTR_ERR(kbd->clk);
227
228 input_dev->name = "Spear Keyboard";
229 input_dev->phys = "keyboard/input0";
230 input_dev->id.bustype = BUS_HOST;
231 input_dev->id.vendor = 0x0001;
232 input_dev->id.product = 0x0001;
233 input_dev->id.version = 0x0100;
234 input_dev->open = spear_kbd_open;
235 input_dev->close = spear_kbd_close;
236
237 error = matrix_keypad_build_keymap(keymap, NULL, NUM_ROWS, NUM_COLS,
238 kbd->keycodes, input_dev);
239 if (error) {
240 dev_err(&pdev->dev, "Failed to build keymap\n");
241 return error;
242 }
243
244 if (kbd->rep)
245 __set_bit(EV_REP, input_dev->evbit);
246 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
247
248 input_set_drvdata(input_dev, kbd);
249
250 error = devm_request_irq(&pdev->dev, irq, spear_kbd_interrupt, 0,
251 "keyboard", kbd);
252 if (error) {
253 dev_err(&pdev->dev, "request_irq failed\n");
254 return error;
255 }
256
257 error = input_register_device(input_dev);
258 if (error) {
259 dev_err(&pdev->dev, "Unable to register keyboard device\n");
260 return error;
261 }
262
263 device_init_wakeup(&pdev->dev, 1);
264 platform_set_drvdata(pdev, kbd);
265
266 return 0;
267 }
268
spear_kbd_suspend(struct device * dev)269 static int spear_kbd_suspend(struct device *dev)
270 {
271 struct platform_device *pdev = to_platform_device(dev);
272 struct spear_kbd *kbd = platform_get_drvdata(pdev);
273 struct input_dev *input_dev = kbd->input;
274 unsigned int rate = 0, mode_ctl_reg, val;
275
276 guard(mutex)(&input_dev->mutex);
277
278 /* explicitly enable clock as we may program device */
279 clk_enable(kbd->clk);
280
281 mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
282
283 if (device_may_wakeup(&pdev->dev)) {
284 if (!enable_irq_wake(kbd->irq))
285 kbd->irq_wake_enabled = true;
286
287 /*
288 * reprogram the keyboard operating frequency as on some
289 * platform it may change during system suspended
290 */
291 if (kbd->suspended_rate)
292 rate = kbd->suspended_rate / 1000000 - 1;
293 else
294 rate = clk_get_rate(kbd->clk) / 1000000 - 1;
295
296 val = mode_ctl_reg &
297 ~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
298 val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
299 << MODE_CTL_PCLK_FREQ_SHIFT;
300 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
301
302 } else {
303 if (input_device_enabled(input_dev)) {
304 writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
305 kbd->io_base + MODE_CTL_REG);
306 clk_disable(kbd->clk);
307 }
308 }
309
310 /* store current configuration */
311 if (input_device_enabled(input_dev))
312 kbd->mode_ctl_reg = mode_ctl_reg;
313
314 /* restore previous clk state */
315 clk_disable(kbd->clk);
316
317 return 0;
318 }
319
spear_kbd_resume(struct device * dev)320 static int spear_kbd_resume(struct device *dev)
321 {
322 struct platform_device *pdev = to_platform_device(dev);
323 struct spear_kbd *kbd = platform_get_drvdata(pdev);
324 struct input_dev *input_dev = kbd->input;
325
326 guard(mutex)(&input_dev->mutex);
327
328 if (device_may_wakeup(&pdev->dev)) {
329 if (kbd->irq_wake_enabled) {
330 kbd->irq_wake_enabled = false;
331 disable_irq_wake(kbd->irq);
332 }
333 } else {
334 if (input_device_enabled(input_dev))
335 clk_enable(kbd->clk);
336 }
337
338 /* restore current configuration */
339 if (input_device_enabled(input_dev))
340 writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
341
342 return 0;
343 }
344
345 static DEFINE_SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops,
346 spear_kbd_suspend, spear_kbd_resume);
347
348 #ifdef CONFIG_OF
349 static const struct of_device_id spear_kbd_id_table[] = {
350 { .compatible = "st,spear300-kbd" },
351 {}
352 };
353 MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
354 #endif
355
356 static struct platform_driver spear_kbd_driver = {
357 .probe = spear_kbd_probe,
358 .driver = {
359 .name = "keyboard",
360 .pm = pm_sleep_ptr(&spear_kbd_pm_ops),
361 .of_match_table = of_match_ptr(spear_kbd_id_table),
362 },
363 };
364 module_platform_driver(spear_kbd_driver);
365
366 MODULE_AUTHOR("Rajeev Kumar");
367 MODULE_DESCRIPTION("SPEAr Keyboard Driver");
368 MODULE_LICENSE("GPL");
369