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(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	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(&pdev->dev, 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, 0, NULL);
222	if (IS_ERR(kbd->io_base))
223		return PTR_ERR(kbd->io_base);
224
225	kbd->clk = devm_clk_get(&pdev->dev, NULL);
226	if (IS_ERR(kbd->clk))
227		return PTR_ERR(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, NULL, NUM_ROWS, NUM_COLS,
239					   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(input_dev, EV_MSC, MSC_SCAN);
248
249	input_set_drvdata(input_dev, kbd);
250
251	error = devm_request_irq(&pdev->dev, irq, spear_kbd_interrupt, 0,
252			"keyboard", kbd);
253	if (error) {
254		dev_err(&pdev->dev, "request_irq failed\n");
255		return error;
256	}
257
258	error = clk_prepare(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(kbd->clk);
266		return error;
267	}
268
269	device_init_wakeup(&pdev->dev, 1);
270	platform_set_drvdata(pdev, kbd);
271
272	return 0;
273}
274
275static void 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(kbd->clk);
281}
282
283static int spear_kbd_suspend(struct device *dev)
284{
285	struct platform_device *pdev = to_platform_device(dev);
286	struct spear_kbd *kbd = platform_get_drvdata(pdev);
287	struct input_dev *input_dev = kbd->input;
288	unsigned int rate = 0, mode_ctl_reg, val;
289
290	mutex_lock(&input_dev->mutex);
291
292	/* explicitly enable clock as we may program device */
293	clk_enable(kbd->clk);
294
295	mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
296
297	if (device_may_wakeup(&pdev->dev)) {
298		if (!enable_irq_wake(kbd->irq))
299			kbd->irq_wake_enabled = true;
300
301		/*
302		 * reprogram the keyboard operating frequency as on some
303		 * platform it may change during system suspended
304		 */
305		if (kbd->suspended_rate)
306			rate = kbd->suspended_rate / 1000000 - 1;
307		else
308			rate = clk_get_rate(kbd->clk) / 1000000 - 1;
309
310		val = mode_ctl_reg &
311			~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
312		val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
313			<< MODE_CTL_PCLK_FREQ_SHIFT;
314		writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
315
316	} else {
317		if (input_device_enabled(input_dev)) {
318			writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
319					kbd->io_base + MODE_CTL_REG);
320			clk_disable(kbd->clk);
321		}
322	}
323
324	/* store current configuration */
325	if (input_device_enabled(input_dev))
326		kbd->mode_ctl_reg = mode_ctl_reg;
327
328	/* restore previous clk state */
329	clk_disable(kbd->clk);
330
331	mutex_unlock(&input_dev->mutex);
332
333	return 0;
334}
335
336static int spear_kbd_resume(struct device *dev)
337{
338	struct platform_device *pdev = to_platform_device(dev);
339	struct spear_kbd *kbd = platform_get_drvdata(pdev);
340	struct input_dev *input_dev = kbd->input;
341
342	mutex_lock(&input_dev->mutex);
343
344	if (device_may_wakeup(&pdev->dev)) {
345		if (kbd->irq_wake_enabled) {
346			kbd->irq_wake_enabled = false;
347			disable_irq_wake(kbd->irq);
348		}
349	} else {
350		if (input_device_enabled(input_dev))
351			clk_enable(kbd->clk);
352	}
353
354	/* restore current configuration */
355	if (input_device_enabled(input_dev))
356		writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
357
358	mutex_unlock(&input_dev->mutex);
359
360	return 0;
361}
362
363static DEFINE_SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops,
364				spear_kbd_suspend, spear_kbd_resume);
365
366#ifdef CONFIG_OF
367static const struct of_device_id spear_kbd_id_table[] = {
368	{ .compatible = "st,spear300-kbd" },
369	{}
370};
371MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
372#endif
373
374static struct platform_driver spear_kbd_driver = {
375	.probe		= spear_kbd_probe,
376	.remove_new	= spear_kbd_remove,
377	.driver		= {
378		.name	= "keyboard",
379		.pm	= pm_sleep_ptr(&spear_kbd_pm_ops),
380		.of_match_table = of_match_ptr(spear_kbd_id_table),
381	},
382};
383module_platform_driver(spear_kbd_driver);
384
385MODULE_AUTHOR("Rajeev Kumar");
386MODULE_DESCRIPTION("SPEAr Keyboard Driver");
387MODULE_LICENSE("GPL");
388