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/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(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
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(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
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(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, "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
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(&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		dev_err(&pdev->dev, "not able to get irq for the device\n");
196		return irq;
197	}
198
199	kbd = devm_kzalloc(&pdev->dev, sizeof(*kbd), GFP_KERNEL);
200	if (!kbd) {
201		dev_err(&pdev->dev, "not enough memory for driver data\n");
202		return -ENOMEM;
203	}
204
205	input_dev = devm_input_allocate_device(&pdev->dev);
206	if (!input_dev) {
207		dev_err(&pdev->dev, "unable to allocate input device\n");
208		return -ENOMEM;
209	}
210
211	kbd->input = input_dev;
212	kbd->irq = irq;
213
214	if (!pdata) {
215		error = spear_kbd_parse_dt(pdev, kbd);
216		if (error)
217			return error;
218	} else {
219		kbd->mode = pdata->mode;
220		kbd->rep = pdata->rep;
221		kbd->suspended_rate = pdata->suspended_rate;
222	}
223
224	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
225	kbd->io_base = devm_ioremap_resource(&pdev->dev, res);
226	if (IS_ERR(kbd->io_base))
227		return PTR_ERR(kbd->io_base);
228
229	kbd->clk = devm_clk_get(&pdev->dev, NULL);
230	if (IS_ERR(kbd->clk))
231		return PTR_ERR(kbd->clk);
232
233	input_dev->name = "Spear Keyboard";
234	input_dev->phys = "keyboard/input0";
235	input_dev->id.bustype = BUS_HOST;
236	input_dev->id.vendor = 0x0001;
237	input_dev->id.product = 0x0001;
238	input_dev->id.version = 0x0100;
239	input_dev->open = spear_kbd_open;
240	input_dev->close = spear_kbd_close;
241
242	error = matrix_keypad_build_keymap(keymap, NULL, NUM_ROWS, NUM_COLS,
243					   kbd->keycodes, input_dev);
244	if (error) {
245		dev_err(&pdev->dev, "Failed to build keymap\n");
246		return error;
247	}
248
249	if (kbd->rep)
250		__set_bit(EV_REP, input_dev->evbit);
251	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
252
253	input_set_drvdata(input_dev, kbd);
254
255	error = devm_request_irq(&pdev->dev, irq, spear_kbd_interrupt, 0,
256			"keyboard", kbd);
257	if (error) {
258		dev_err(&pdev->dev, "request_irq failed\n");
259		return error;
260	}
261
262	error = clk_prepare(kbd->clk);
263	if (error)
264		return error;
265
266	error = input_register_device(input_dev);
267	if (error) {
268		dev_err(&pdev->dev, "Unable to register keyboard device\n");
269		clk_unprepare(kbd->clk);
270		return error;
271	}
272
273	device_init_wakeup(&pdev->dev, 1);
274	platform_set_drvdata(pdev, kbd);
275
276	return 0;
277}
278
279static int spear_kbd_remove(struct platform_device *pdev)
280{
281	struct spear_kbd *kbd = platform_get_drvdata(pdev);
282
283	input_unregister_device(kbd->input);
284	clk_unprepare(kbd->clk);
285
286	device_init_wakeup(&pdev->dev, 0);
287
288	return 0;
289}
290
291#ifdef CONFIG_PM
292static int spear_kbd_suspend(struct device *dev)
293{
294	struct platform_device *pdev = to_platform_device(dev);
295	struct spear_kbd *kbd = platform_get_drvdata(pdev);
296	struct input_dev *input_dev = kbd->input;
297	unsigned int rate = 0, mode_ctl_reg, val;
298
299	mutex_lock(&input_dev->mutex);
300
301	/* explicitly enable clock as we may program device */
302	clk_enable(kbd->clk);
303
304	mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
305
306	if (device_may_wakeup(&pdev->dev)) {
307		if (!enable_irq_wake(kbd->irq))
308			kbd->irq_wake_enabled = true;
309
310		/*
311		 * reprogram the keyboard operating frequency as on some
312		 * platform it may change during system suspended
313		 */
314		if (kbd->suspended_rate)
315			rate = kbd->suspended_rate / 1000000 - 1;
316		else
317			rate = clk_get_rate(kbd->clk) / 1000000 - 1;
318
319		val = mode_ctl_reg &
320			~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
321		val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
322			<< MODE_CTL_PCLK_FREQ_SHIFT;
323		writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
324
325	} else {
326		if (input_dev->users) {
327			writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
328					kbd->io_base + MODE_CTL_REG);
329			clk_disable(kbd->clk);
330		}
331	}
332
333	/* store current configuration */
334	if (input_dev->users)
335		kbd->mode_ctl_reg = mode_ctl_reg;
336
337	/* restore previous clk state */
338	clk_disable(kbd->clk);
339
340	mutex_unlock(&input_dev->mutex);
341
342	return 0;
343}
344
345static int spear_kbd_resume(struct device *dev)
346{
347	struct platform_device *pdev = to_platform_device(dev);
348	struct spear_kbd *kbd = platform_get_drvdata(pdev);
349	struct input_dev *input_dev = kbd->input;
350
351	mutex_lock(&input_dev->mutex);
352
353	if (device_may_wakeup(&pdev->dev)) {
354		if (kbd->irq_wake_enabled) {
355			kbd->irq_wake_enabled = false;
356			disable_irq_wake(kbd->irq);
357		}
358	} else {
359		if (input_dev->users)
360			clk_enable(kbd->clk);
361	}
362
363	/* restore current configuration */
364	if (input_dev->users)
365		writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
366
367	mutex_unlock(&input_dev->mutex);
368
369	return 0;
370}
371#endif
372
373static SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops, spear_kbd_suspend, spear_kbd_resume);
374
375#ifdef CONFIG_OF
376static const struct of_device_id spear_kbd_id_table[] = {
377	{ .compatible = "st,spear300-kbd" },
378	{}
379};
380MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
381#endif
382
383static struct platform_driver spear_kbd_driver = {
384	.probe		= spear_kbd_probe,
385	.remove		= spear_kbd_remove,
386	.driver		= {
387		.name	= "keyboard",
388		.pm	= &spear_kbd_pm_ops,
389		.of_match_table = of_match_ptr(spear_kbd_id_table),
390	},
391};
392module_platform_driver(spear_kbd_driver);
393
394MODULE_AUTHOR("Rajeev Kumar");
395MODULE_DESCRIPTION("SPEAr Keyboard Driver");
396MODULE_LICENSE("GPL");
397