1/*
  2 * Texas Instruments TNETV107X Keypad Driver
  3 *
  4 * Copyright (C) 2010 Texas Instruments
  5 *
  6 * This program is free software; you can redistribute it and/or
  7 * modify it under the terms of the GNU General Public License as
  8 * published by the Free Software Foundation version 2.
  9 *
 10 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 11 * kind, whether express or implied; without even the implied warranty
 12 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 */
 15
 16#include <linux/kernel.h>
 17#include <linux/err.h>
 18#include <linux/errno.h>
 19#include <linux/input.h>
 20#include <linux/platform_device.h>
 21#include <linux/interrupt.h>
 22#include <linux/slab.h>
 23#include <linux/delay.h>
 24#include <linux/io.h>
 25#include <linux/clk.h>
 26#include <linux/input/matrix_keypad.h>
 27
 28#define BITS(x)			(BIT(x) - 1)
 29
 30#define KEYPAD_ROWS		9
 31#define KEYPAD_COLS		9
 32
 33#define DEBOUNCE_MIN		0x400ul
 34#define DEBOUNCE_MAX		0x3ffffffful
 35
 36struct keypad_regs {
 37	u32	rev;
 38	u32	mode;
 39	u32	mask;
 40	u32	pol;
 41	u32	dclock;
 42	u32	rclock;
 43	u32	stable_cnt;
 44	u32	in_en;
 45	u32	out;
 46	u32	out_en;
 47	u32	in;
 48	u32	lock;
 49	u32	pres[3];
 50};
 51
 52#define keypad_read(kp, reg)		__raw_readl(&(kp)->regs->reg)
 53#define keypad_write(kp, reg, val)	__raw_writel(val, &(kp)->regs->reg)
 54
 55struct keypad_data {
 56	struct input_dev		*input_dev;
 57	struct resource			*res;
 58	struct keypad_regs __iomem	*regs;
 59	struct clk			*clk;
 60	struct device			*dev;
 61	spinlock_t			lock;
 62	u32				irq_press;
 63	u32				irq_release;
 64	int				rows, cols, row_shift;
 65	int				debounce_ms, active_low;
 66	u32				prev_keys[3];
 67	unsigned short			keycodes[];
 68};
 69
 70static irqreturn_t keypad_irq(int irq, void *data)
 71{
 72	struct keypad_data *kp = data;
 73	int i, bit, val, row, col, code;
 74	unsigned long flags;
 75	u32 curr_keys[3];
 76	u32 change;
 77
 78	spin_lock_irqsave(&kp->lock, flags);
 79
 80	memset(curr_keys, 0, sizeof(curr_keys));
 81	if (irq == kp->irq_press)
 82		for (i = 0; i < 3; i++)
 83			curr_keys[i] = keypad_read(kp, pres[i]);
 84
 85	for (i = 0; i < 3; i++) {
 86		change = curr_keys[i] ^ kp->prev_keys[i];
 87
 88		while (change) {
 89			bit     = fls(change) - 1;
 90			change ^= BIT(bit);
 91			val     = curr_keys[i] & BIT(bit);
 92			bit    += i * 32;
 93			row     = bit / KEYPAD_COLS;
 94			col     = bit % KEYPAD_COLS;
 95
 96			code = MATRIX_SCAN_CODE(row, col, kp->row_shift);
 97			input_event(kp->input_dev, EV_MSC, MSC_SCAN, code);
 98			input_report_key(kp->input_dev, kp->keycodes[code],
 99					 val);
100		}
101	}
102	input_sync(kp->input_dev);
103	memcpy(kp->prev_keys, curr_keys, sizeof(curr_keys));
104
105	if (irq == kp->irq_press)
106		keypad_write(kp, lock, 0); /* Allow hardware updates */
107
108	spin_unlock_irqrestore(&kp->lock, flags);
109
110	return IRQ_HANDLED;
111}
112
113static int keypad_start(struct input_dev *dev)
114{
115	struct keypad_data *kp = input_get_drvdata(dev);
116	unsigned long mask, debounce, clk_rate_khz;
117	unsigned long flags;
118
119	clk_enable(kp->clk);
120	clk_rate_khz = clk_get_rate(kp->clk) / 1000;
121
122	spin_lock_irqsave(&kp->lock, flags);
123
124	/* Initialize device registers */
125	keypad_write(kp, mode, 0);
126
127	mask  = BITS(kp->rows) << KEYPAD_COLS;
128	mask |= BITS(kp->cols);
129	keypad_write(kp, mask, ~mask);
130
131	keypad_write(kp, pol, kp->active_low ? 0 : 0x3ffff);
132	keypad_write(kp, stable_cnt, 3);
133
134	debounce = kp->debounce_ms * clk_rate_khz;
135	debounce = clamp(debounce, DEBOUNCE_MIN, DEBOUNCE_MAX);
136	keypad_write(kp, dclock, debounce);
137	keypad_write(kp, rclock, 4 * debounce);
138
139	keypad_write(kp, in_en, 1);
140
141	spin_unlock_irqrestore(&kp->lock, flags);
142
143	return 0;
144}
145
146static void keypad_stop(struct input_dev *dev)
147{
148	struct keypad_data *kp = input_get_drvdata(dev);
149
150	synchronize_irq(kp->irq_press);
151	synchronize_irq(kp->irq_release);
152	clk_disable(kp->clk);
153}
154
155static int __devinit keypad_probe(struct platform_device *pdev)
156{
157	const struct matrix_keypad_platform_data *pdata;
158	const struct matrix_keymap_data *keymap_data;
159	struct device *dev = &pdev->dev;
160	struct keypad_data *kp;
161	int error = 0, sz, row_shift;
162	u32 rev = 0;
163
164	pdata = pdev->dev.platform_data;
165	if (!pdata) {
166		dev_err(dev, "cannot find device data\n");
167		return -EINVAL;
168	}
169
170	keymap_data = pdata->keymap_data;
171	if (!keymap_data) {
172		dev_err(dev, "cannot find keymap data\n");
173		return -EINVAL;
174	}
175
176	row_shift = get_count_order(pdata->num_col_gpios);
177	sz  = offsetof(struct keypad_data, keycodes);
178	sz += (pdata->num_row_gpios << row_shift) * sizeof(kp->keycodes[0]);
179	kp = kzalloc(sz, GFP_KERNEL);
180	if (!kp) {
181		dev_err(dev, "cannot allocate device info\n");
182		return -ENOMEM;
183	}
184
185	kp->dev  = dev;
186	kp->rows = pdata->num_row_gpios;
187	kp->cols = pdata->num_col_gpios;
188	kp->row_shift = row_shift;
189	platform_set_drvdata(pdev, kp);
190	spin_lock_init(&kp->lock);
191
192	kp->irq_press   = platform_get_irq_byname(pdev, "press");
193	kp->irq_release = platform_get_irq_byname(pdev, "release");
194	if (kp->irq_press < 0 || kp->irq_release < 0) {
195		dev_err(dev, "cannot determine device interrupts\n");
196		error = -ENODEV;
197		goto error_res;
198	}
199
200	kp->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
201	if (!kp->res) {
202		dev_err(dev, "cannot determine register area\n");
203		error = -ENODEV;
204		goto error_res;
205	}
206
207	if (!request_mem_region(kp->res->start, resource_size(kp->res),
208				pdev->name)) {
209		dev_err(dev, "cannot claim register memory\n");
210		kp->res = NULL;
211		error = -EINVAL;
212		goto error_res;
213	}
214
215	kp->regs = ioremap(kp->res->start, resource_size(kp->res));
216	if (!kp->regs) {
217		dev_err(dev, "cannot map register memory\n");
218		error = -ENOMEM;
219		goto error_map;
220	}
221
222	kp->clk = clk_get(dev, NULL);
223	if (IS_ERR(kp->clk)) {
224		dev_err(dev, "cannot claim device clock\n");
225		error = PTR_ERR(kp->clk);
226		goto error_clk;
227	}
228
229	error = request_threaded_irq(kp->irq_press, NULL, keypad_irq, 0,
230				     dev_name(dev), kp);
231	if (error < 0) {
232		dev_err(kp->dev, "Could not allocate keypad press key irq\n");
233		goto error_irq_press;
234	}
235
236	error = request_threaded_irq(kp->irq_release, NULL, keypad_irq, 0,
237				     dev_name(dev), kp);
238	if (error < 0) {
239		dev_err(kp->dev, "Could not allocate keypad release key irq\n");
240		goto error_irq_release;
241	}
242
243	kp->input_dev = input_allocate_device();
244	if (!kp->input_dev) {
245		dev_err(dev, "cannot allocate input device\n");
246		error = -ENOMEM;
247		goto error_input;
248	}
249	input_set_drvdata(kp->input_dev, kp);
250
251	kp->input_dev->name	  = pdev->name;
252	kp->input_dev->dev.parent = &pdev->dev;
253	kp->input_dev->open	  = keypad_start;
254	kp->input_dev->close	  = keypad_stop;
255	kp->input_dev->evbit[0]	  = BIT_MASK(EV_KEY);
256	if (!pdata->no_autorepeat)
257		kp->input_dev->evbit[0] |= BIT_MASK(EV_REP);
258
259	clk_enable(kp->clk);
260	rev = keypad_read(kp, rev);
261	kp->input_dev->id.bustype = BUS_HOST;
262	kp->input_dev->id.product = ((rev >>  8) & 0x07);
263	kp->input_dev->id.version = ((rev >> 16) & 0xfff);
264	clk_disable(kp->clk);
265
266	kp->input_dev->keycode     = kp->keycodes;
267	kp->input_dev->keycodesize = sizeof(kp->keycodes[0]);
268	kp->input_dev->keycodemax  = kp->rows << kp->row_shift;
269
270	matrix_keypad_build_keymap(keymap_data, kp->row_shift, kp->keycodes,
271				   kp->input_dev->keybit);
272
273	input_set_capability(kp->input_dev, EV_MSC, MSC_SCAN);
274
275	error = input_register_device(kp->input_dev);
276	if (error < 0) {
277		dev_err(dev, "Could not register input device\n");
278		goto error_reg;
279	}
280
281	return 0;
282
283
284error_reg:
285	input_free_device(kp->input_dev);
286error_input:
287	free_irq(kp->irq_release, kp);
288error_irq_release:
289	free_irq(kp->irq_press, kp);
290error_irq_press:
291	clk_put(kp->clk);
292error_clk:
293	iounmap(kp->regs);
294error_map:
295	release_mem_region(kp->res->start, resource_size(kp->res));
296error_res:
297	platform_set_drvdata(pdev, NULL);
298	kfree(kp);
299	return error;
300}
301
302static int __devexit keypad_remove(struct platform_device *pdev)
303{
304	struct keypad_data *kp = platform_get_drvdata(pdev);
305
306	free_irq(kp->irq_press, kp);
307	free_irq(kp->irq_release, kp);
308	input_unregister_device(kp->input_dev);
309	clk_put(kp->clk);
310	iounmap(kp->regs);
311	release_mem_region(kp->res->start, resource_size(kp->res));
312	platform_set_drvdata(pdev, NULL);
313	kfree(kp);
314
315	return 0;
316}
317
318static struct platform_driver keypad_driver = {
319	.probe		= keypad_probe,
320	.remove		= __devexit_p(keypad_remove),
321	.driver.name	= "tnetv107x-keypad",
322	.driver.owner	= THIS_MODULE,
323};
324
325static int __init keypad_init(void)
326{
327	return platform_driver_register(&keypad_driver);
328}
329
330static void __exit keypad_exit(void)
331{
332	platform_driver_unregister(&keypad_driver);
333}
334
335module_init(keypad_init);
336module_exit(keypad_exit);
337
338MODULE_AUTHOR("Cyril Chemparathy");
339MODULE_DESCRIPTION("TNETV107X Keypad Driver");
340MODULE_ALIAS("platform:tnetv107x-keypad");
341MODULE_LICENSE("GPL");