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
55struct 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
69static 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(dev: input, code: kbd->last_key, value: 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(dev: input, EV_MSC, MSC_SCAN, value: val);
91 input_report_key(dev: input, code: key, value: 1);
92 input_sync(dev: 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
102static 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(clk: 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(clk: 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
132static 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(clk: kbd->clk);
143
144 kbd->last_key = KEY_RESERVED;
145}
146
147#ifdef CONFIG_OF
148static 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, propname: "autorepeat"))
161 kbd->rep = true;
162
163 if (of_property_read_u32(np, propname: "suspended_rate", out_value: &suspended_rate))
164 kbd->suspended_rate = suspended_rate;
165
166 error = of_property_read_u32(np, propname: "st,mode", out_value: &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
176static inline int spear_kbd_parse_dt(struct platform_device *pdev,
177 struct spear_kbd *kbd)
178{
179 return -ENOSYS;
180}
181#endif
182
183static int spear_kbd_probe(struct platform_device *pdev)
184{
185 struct kbd_platform_data *pdata = dev_get_platdata(dev: &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 int irq;
190 int error;
191
192 irq = platform_get_irq(pdev, 0);
193 if (irq < 0)
194 return irq;
195
196 kbd = devm_kzalloc(dev: &pdev->dev, size: sizeof(*kbd), GFP_KERNEL);
197 if (!kbd) {
198 dev_err(&pdev->dev, "not enough memory for driver data\n");
199 return -ENOMEM;
200 }
201
202 input_dev = devm_input_allocate_device(&pdev->dev);
203 if (!input_dev) {
204 dev_err(&pdev->dev, "unable to allocate input device\n");
205 return -ENOMEM;
206 }
207
208 kbd->input = input_dev;
209 kbd->irq = irq;
210
211 if (!pdata) {
212 error = spear_kbd_parse_dt(pdev, kbd);
213 if (error)
214 return error;
215 } else {
216 kbd->mode = pdata->mode;
217 kbd->rep = pdata->rep;
218 kbd->suspended_rate = pdata->suspended_rate;
219 }
220
221 kbd->io_base = devm_platform_get_and_ioremap_resource(pdev, index: 0, NULL);
222 if (IS_ERR(ptr: kbd->io_base))
223 return PTR_ERR(ptr: kbd->io_base);
224
225 kbd->clk = devm_clk_get(dev: &pdev->dev, NULL);
226 if (IS_ERR(ptr: kbd->clk))
227 return PTR_ERR(ptr: kbd->clk);
228
229 input_dev->name = "Spear Keyboard";
230 input_dev->phys = "keyboard/input0";
231 input_dev->id.bustype = BUS_HOST;
232 input_dev->id.vendor = 0x0001;
233 input_dev->id.product = 0x0001;
234 input_dev->id.version = 0x0100;
235 input_dev->open = spear_kbd_open;
236 input_dev->close = spear_kbd_close;
237
238 error = matrix_keypad_build_keymap(keymap_data: keymap, NULL, NUM_ROWS, NUM_COLS,
239 keymap: kbd->keycodes, input_dev);
240 if (error) {
241 dev_err(&pdev->dev, "Failed to build keymap\n");
242 return error;
243 }
244
245 if (kbd->rep)
246 __set_bit(EV_REP, input_dev->evbit);
247 input_set_capability(dev: input_dev, EV_MSC, MSC_SCAN);
248
249 input_set_drvdata(dev: input_dev, data: kbd);
250
251 error = devm_request_irq(dev: &pdev->dev, irq, handler: spear_kbd_interrupt, irqflags: 0,
252 devname: "keyboard", dev_id: kbd);
253 if (error) {
254 dev_err(&pdev->dev, "request_irq failed\n");
255 return error;
256 }
257
258 error = clk_prepare(clk: kbd->clk);
259 if (error)
260 return error;
261
262 error = input_register_device(input_dev);
263 if (error) {
264 dev_err(&pdev->dev, "Unable to register keyboard device\n");
265 clk_unprepare(clk: kbd->clk);
266 return error;
267 }
268
269 device_init_wakeup(dev: &pdev->dev, enable: 1);
270 platform_set_drvdata(pdev, data: kbd);
271
272 return 0;
273}
274
275static int spear_kbd_remove(struct platform_device *pdev)
276{
277 struct spear_kbd *kbd = platform_get_drvdata(pdev);
278
279 input_unregister_device(kbd->input);
280 clk_unprepare(clk: kbd->clk);
281
282 return 0;
283}
284
285static int spear_kbd_suspend(struct device *dev)
286{
287 struct platform_device *pdev = to_platform_device(dev);
288 struct spear_kbd *kbd = platform_get_drvdata(pdev);
289 struct input_dev *input_dev = kbd->input;
290 unsigned int rate = 0, mode_ctl_reg, val;
291
292 mutex_lock(&input_dev->mutex);
293
294 /* explicitly enable clock as we may program device */
295 clk_enable(clk: kbd->clk);
296
297 mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
298
299 if (device_may_wakeup(dev: &pdev->dev)) {
300 if (!enable_irq_wake(irq: kbd->irq))
301 kbd->irq_wake_enabled = true;
302
303 /*
304 * reprogram the keyboard operating frequency as on some
305 * platform it may change during system suspended
306 */
307 if (kbd->suspended_rate)
308 rate = kbd->suspended_rate / 1000000 - 1;
309 else
310 rate = clk_get_rate(clk: kbd->clk) / 1000000 - 1;
311
312 val = mode_ctl_reg &
313 ~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
314 val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
315 << MODE_CTL_PCLK_FREQ_SHIFT;
316 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
317
318 } else {
319 if (input_device_enabled(dev: input_dev)) {
320 writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
321 kbd->io_base + MODE_CTL_REG);
322 clk_disable(clk: kbd->clk);
323 }
324 }
325
326 /* store current configuration */
327 if (input_device_enabled(dev: input_dev))
328 kbd->mode_ctl_reg = mode_ctl_reg;
329
330 /* restore previous clk state */
331 clk_disable(clk: kbd->clk);
332
333 mutex_unlock(lock: &input_dev->mutex);
334
335 return 0;
336}
337
338static int spear_kbd_resume(struct device *dev)
339{
340 struct platform_device *pdev = to_platform_device(dev);
341 struct spear_kbd *kbd = platform_get_drvdata(pdev);
342 struct input_dev *input_dev = kbd->input;
343
344 mutex_lock(&input_dev->mutex);
345
346 if (device_may_wakeup(dev: &pdev->dev)) {
347 if (kbd->irq_wake_enabled) {
348 kbd->irq_wake_enabled = false;
349 disable_irq_wake(irq: kbd->irq);
350 }
351 } else {
352 if (input_device_enabled(dev: input_dev))
353 clk_enable(clk: kbd->clk);
354 }
355
356 /* restore current configuration */
357 if (input_device_enabled(dev: input_dev))
358 writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
359
360 mutex_unlock(lock: &input_dev->mutex);
361
362 return 0;
363}
364
365static DEFINE_SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops,
366 spear_kbd_suspend, spear_kbd_resume);
367
368#ifdef CONFIG_OF
369static const struct of_device_id spear_kbd_id_table[] = {
370 { .compatible = "st,spear300-kbd" },
371 {}
372};
373MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
374#endif
375
376static struct platform_driver spear_kbd_driver = {
377 .probe = spear_kbd_probe,
378 .remove = spear_kbd_remove,
379 .driver = {
380 .name = "keyboard",
381 .pm = pm_sleep_ptr(&spear_kbd_pm_ops),
382 .of_match_table = of_match_ptr(spear_kbd_id_table),
383 },
384};
385module_platform_driver(spear_kbd_driver);
386
387MODULE_AUTHOR("Rajeev Kumar");
388MODULE_DESCRIPTION("SPEAr Keyboard Driver");
389MODULE_LICENSE("GPL");
390

source code of linux/drivers/input/keyboard/spear-keyboard.c