tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * SPEAr Keyboard Driver
3 * Based on omap-keypad driver
4 *
5 * Copyright (C) 2010 ST Microelectronics
6 * Rajeev Kumar<rajeev-dlh.kumar@st.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/init.h>
16#include <linux/interrupt.h>
17#include <linux/input.h>
18#include <linux/io.h>
19#include <linux/irq.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/of.h>
23#include <linux/platform_device.h>
24#include <linux/pm_wakeup.h>
25#include <linux/slab.h>
26#include <linux/types.h>
27#include <linux/platform_data/keyboard-spear.h>
28
29/* Keyboard Registers */
30#define MODE_CTL_REG 0x00
31#define STATUS_REG 0x0C
32#define DATA_REG 0x10
33#define INTR_MASK 0x54
34
35/* Register Values */
36#define NUM_ROWS 16
37#define NUM_COLS 16
38#define MODE_CTL_PCLK_FREQ_SHIFT 9
39#define MODE_CTL_PCLK_FREQ_MSK 0x7F
40
41#define MODE_CTL_KEYBOARD (0x2 << 0)
42#define MODE_CTL_SCAN_RATE_10 (0x0 << 2)
43#define MODE_CTL_SCAN_RATE_20 (0x1 << 2)
44#define MODE_CTL_SCAN_RATE_40 (0x2 << 2)
45#define MODE_CTL_SCAN_RATE_80 (0x3 << 2)
46#define MODE_CTL_KEYNUM_SHIFT 6
47#define MODE_CTL_START_SCAN (0x1 << 8)
48
49#define STATUS_DATA_AVAIL (0x1 << 1)
50
51#define DATA_ROW_MASK 0xF0
52#define DATA_COLUMN_MASK 0x0F
53
54#define ROW_SHIFT 4
55
56struct spear_kbd {
57 struct input_dev *input;
58 void __iomem *io_base;
59 struct clk *clk;
60 unsigned int irq;
61 unsigned int mode;
62 unsigned int suspended_rate;
63 unsigned short last_key;
64 unsigned short keycodes[NUM_ROWS * NUM_COLS];
65 bool rep;
66 bool irq_wake_enabled;
67 u32 mode_ctl_reg;
68};
69
70static irqreturn_t spear_kbd_interrupt(int irq, void *dev_id)
71{
72 struct spear_kbd *kbd = dev_id;
73 struct input_dev *input = kbd->input;
74 unsigned int key;
75 u32 sts, val;
76
77 sts = readl_relaxed(kbd->io_base + STATUS_REG);
78 if (!(sts & STATUS_DATA_AVAIL))
79 return IRQ_NONE;
80
81 if (kbd->last_key != KEY_RESERVED) {
82 input_report_key(input, kbd->last_key, 0);
83 kbd->last_key = KEY_RESERVED;
84 }
85
86 /* following reads active (row, col) pair */
87 val = readl_relaxed(kbd->io_base + DATA_REG) &
88 (DATA_ROW_MASK | DATA_COLUMN_MASK);
89 key = kbd->keycodes[val];
90
91 input_event(input, EV_MSC, MSC_SCAN, val);
92 input_report_key(input, key, 1);
93 input_sync(input);
94
95 kbd->last_key = key;
96
97 /* clear interrupt */
98 writel_relaxed(0, kbd->io_base + STATUS_REG);
99
100 return IRQ_HANDLED;
101}
102
103static int spear_kbd_open(struct input_dev *dev)
104{
105 struct spear_kbd *kbd = input_get_drvdata(dev);
106 int error;
107 u32 val;
108
109 kbd->last_key = KEY_RESERVED;
110
111 error = clk_enable(kbd->clk);
112 if (error)
113 return error;
114
115 /* keyboard rate to be programmed is input clock (in MHz) - 1 */
116 val = clk_get_rate(kbd->clk) / 1000000 - 1;
117 val = (val & MODE_CTL_PCLK_FREQ_MSK) << MODE_CTL_PCLK_FREQ_SHIFT;
118
119 /* program keyboard */
120 val = MODE_CTL_SCAN_RATE_80 | MODE_CTL_KEYBOARD | val |
121 (kbd->mode << MODE_CTL_KEYNUM_SHIFT);
122 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
123 writel_relaxed(1, kbd->io_base + STATUS_REG);
124
125 /* start key scan */
126 val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
127 val |= MODE_CTL_START_SCAN;
128 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
129
130 return 0;
131}
132
133static void spear_kbd_close(struct input_dev *dev)
134{
135 struct spear_kbd *kbd = input_get_drvdata(dev);
136 u32 val;
137
138 /* stop key scan */
139 val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
140 val &= ~MODE_CTL_START_SCAN;
141 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
142
143 clk_disable(kbd->clk);
144
145 kbd->last_key = KEY_RESERVED;
146}
147
148#ifdef CONFIG_OF
149static int spear_kbd_parse_dt(struct platform_device *pdev,
150 struct spear_kbd *kbd)
151{
152 struct device_node *np = pdev->dev.of_node;
153 int error;
154 u32 val, suspended_rate;
155
156 if (!np) {
157 dev_err(&pdev->dev, "Missing DT data\n");
158 return -EINVAL;
159 }
160
161 if (of_property_read_bool(np, "autorepeat"))
162 kbd->rep = true;
163
164 if (of_property_read_u32(np, "suspended_rate", &suspended_rate))
165 kbd->suspended_rate = suspended_rate;
166
167 error = of_property_read_u32(np, "st,mode", &val);
168 if (error) {
169 dev_err(&pdev->dev, "DT: Invalid or missing mode\n");
170 return error;
171 }
172
173 kbd->mode = val;
174 return 0;
175}
176#else
177static inline int spear_kbd_parse_dt(struct platform_device *pdev,
178 struct spear_kbd *kbd)
179{
180 return -ENOSYS;
181}
182#endif
183
184static int spear_kbd_probe(struct platform_device *pdev)
185{
186 struct kbd_platform_data *pdata = dev_get_platdata(&pdev->dev);
187 const struct matrix_keymap_data *keymap = pdata ? pdata->keymap : NULL;
188 struct spear_kbd *kbd;
189 struct input_dev *input_dev;
190 struct resource *res;
191 int irq;
192 int error;
193
194 irq = platform_get_irq(pdev, 0);
195 if (irq < 0) {
196 dev_err(&pdev->dev, "not able to get irq for the device\n");
197 return irq;
198 }
199
200 kbd = devm_kzalloc(&pdev->dev, sizeof(*kbd), GFP_KERNEL);
201 if (!kbd) {
202 dev_err(&pdev->dev, "not enough memory for driver data\n");
203 return -ENOMEM;
204 }
205
206 input_dev = devm_input_allocate_device(&pdev->dev);
207 if (!input_dev) {
208 dev_err(&pdev->dev, "unable to allocate input device\n");
209 return -ENOMEM;
210 }
211
212 kbd->input = input_dev;
213 kbd->irq = irq;
214
215 if (!pdata) {
216 error = spear_kbd_parse_dt(pdev, kbd);
217 if (error)
218 return error;
219 } else {
220 kbd->mode = pdata->mode;
221 kbd->rep = pdata->rep;
222 kbd->suspended_rate = pdata->suspended_rate;
223 }
224
225 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
226 kbd->io_base = devm_ioremap_resource(&pdev->dev, res);
227 if (IS_ERR(kbd->io_base))
228 return PTR_ERR(kbd->io_base);
229
230 kbd->clk = devm_clk_get(&pdev->dev, NULL);
231 if (IS_ERR(kbd->clk))
232 return PTR_ERR(kbd->clk);
233
234 input_dev->name = "Spear Keyboard";
235 input_dev->phys = "keyboard/input0";
236 input_dev->id.bustype = BUS_HOST;
237 input_dev->id.vendor = 0x0001;
238 input_dev->id.product = 0x0001;
239 input_dev->id.version = 0x0100;
240 input_dev->open = spear_kbd_open;
241 input_dev->close = spear_kbd_close;
242
243 error = matrix_keypad_build_keymap(keymap, NULL, NUM_ROWS, NUM_COLS,
244 kbd->keycodes, input_dev);
245 if (error) {
246 dev_err(&pdev->dev, "Failed to build keymap\n");
247 return error;
248 }
249
250 if (kbd->rep)
251 __set_bit(EV_REP, input_dev->evbit);
252 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
253
254 input_set_drvdata(input_dev, kbd);
255
256 error = devm_request_irq(&pdev->dev, irq, spear_kbd_interrupt, 0,
257 "keyboard", kbd);
258 if (error) {
259 dev_err(&pdev->dev, "request_irq failed\n");
260 return error;
261 }
262
263 error = clk_prepare(kbd->clk);
264 if (error)
265 return error;
266
267 error = input_register_device(input_dev);
268 if (error) {
269 dev_err(&pdev->dev, "Unable to register keyboard device\n");
270 clk_unprepare(kbd->clk);
271 return error;
272 }
273
274 device_init_wakeup(&pdev->dev, 1);
275 platform_set_drvdata(pdev, kbd);
276
277 return 0;
278}
279
280static int spear_kbd_remove(struct platform_device *pdev)
281{
282 struct spear_kbd *kbd = platform_get_drvdata(pdev);
283
284 input_unregister_device(kbd->input);
285 clk_unprepare(kbd->clk);
286
287 device_init_wakeup(&pdev->dev, 0);
288
289 return 0;
290}
291
292#ifdef CONFIG_PM
293static int spear_kbd_suspend(struct device *dev)
294{
295 struct platform_device *pdev = to_platform_device(dev);
296 struct spear_kbd *kbd = platform_get_drvdata(pdev);
297 struct input_dev *input_dev = kbd->input;
298 unsigned int rate = 0, mode_ctl_reg, val;
299
300 mutex_lock(&input_dev->mutex);
301
302 /* explicitly enable clock as we may program device */
303 clk_enable(kbd->clk);
304
305 mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
306
307 if (device_may_wakeup(&pdev->dev)) {
308 if (!enable_irq_wake(kbd->irq))
309 kbd->irq_wake_enabled = true;
310
311 /*
312 * reprogram the keyboard operating frequency as on some
313 * platform it may change during system suspended
314 */
315 if (kbd->suspended_rate)
316 rate = kbd->suspended_rate / 1000000 - 1;
317 else
318 rate = clk_get_rate(kbd->clk) / 1000000 - 1;
319
320 val = mode_ctl_reg &
321 ~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
322 val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
323 << MODE_CTL_PCLK_FREQ_SHIFT;
324 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
325
326 } else {
327 if (input_dev->users) {
328 writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
329 kbd->io_base + MODE_CTL_REG);
330 clk_disable(kbd->clk);
331 }
332 }
333
334 /* store current configuration */
335 if (input_dev->users)
336 kbd->mode_ctl_reg = mode_ctl_reg;
337
338 /* restore previous clk state */
339 clk_disable(kbd->clk);
340
341 mutex_unlock(&input_dev->mutex);
342
343 return 0;
344}
345
346static int spear_kbd_resume(struct device *dev)
347{
348 struct platform_device *pdev = to_platform_device(dev);
349 struct spear_kbd *kbd = platform_get_drvdata(pdev);
350 struct input_dev *input_dev = kbd->input;
351
352 mutex_lock(&input_dev->mutex);
353
354 if (device_may_wakeup(&pdev->dev)) {
355 if (kbd->irq_wake_enabled) {
356 kbd->irq_wake_enabled = false;
357 disable_irq_wake(kbd->irq);
358 }
359 } else {
360 if (input_dev->users)
361 clk_enable(kbd->clk);
362 }
363
364 /* restore current configuration */
365 if (input_dev->users)
366 writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
367
368 mutex_unlock(&input_dev->mutex);
369
370 return 0;
371}
372#endif
373
374static SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops, spear_kbd_suspend, spear_kbd_resume);
375
376#ifdef CONFIG_OF
377static const struct of_device_id spear_kbd_id_table[] = {
378 { .compatible = "st,spear300-kbd" },
379 {}
380};
381MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
382#endif
383
384static struct platform_driver spear_kbd_driver = {
385 .probe = spear_kbd_probe,
386 .remove = spear_kbd_remove,
387 .driver = {
388 .name = "keyboard",
389 .owner = THIS_MODULE,
390 .pm = &spear_kbd_pm_ops,
391 .of_match_table = of_match_ptr(spear_kbd_id_table),
392 },
393};
394module_platform_driver(spear_kbd_driver);
395
396MODULE_AUTHOR("Rajeev Kumar");
397MODULE_DESCRIPTION("SPEAr Keyboard Driver");
398MODULE_LICENSE("GPL");