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1/*
2 * NXP LPC32xx SoC Key Scan Interface
3 *
4 * Authors:
5 * Kevin Wells <kevin.wells@nxp.com>
6 * Roland Stigge <stigge@antcom.de>
7 *
8 * Copyright (C) 2010 NXP Semiconductors
9 * Copyright (C) 2012 Roland Stigge
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 *
22 * This controller supports square key matrices from 1x1 up to 8x8
23 */
24
25#include <linux/module.h>
26#include <linux/interrupt.h>
27#include <linux/slab.h>
28#include <linux/irq.h>
29#include <linux/pm.h>
30#include <linux/platform_device.h>
31#include <linux/input.h>
32#include <linux/clk.h>
33#include <linux/io.h>
34#include <linux/of.h>
35#include <linux/input/matrix_keypad.h>
36
37#define DRV_NAME "lpc32xx_keys"
38
39/*
40 * Key scanner register offsets
41 */
42#define LPC32XX_KS_DEB(x) ((x) + 0x00)
43#define LPC32XX_KS_STATE_COND(x) ((x) + 0x04)
44#define LPC32XX_KS_IRQ(x) ((x) + 0x08)
45#define LPC32XX_KS_SCAN_CTL(x) ((x) + 0x0C)
46#define LPC32XX_KS_FAST_TST(x) ((x) + 0x10)
47#define LPC32XX_KS_MATRIX_DIM(x) ((x) + 0x14) /* 1..8 */
48#define LPC32XX_KS_DATA(x, y) ((x) + 0x40 + ((y) << 2))
49
50#define LPC32XX_KSCAN_DEB_NUM_DEB_PASS(n) ((n) & 0xFF)
51
52#define LPC32XX_KSCAN_SCOND_IN_IDLE 0x0
53#define LPC32XX_KSCAN_SCOND_IN_SCANONCE 0x1
54#define LPC32XX_KSCAN_SCOND_IN_IRQGEN 0x2
55#define LPC32XX_KSCAN_SCOND_IN_SCAN_MATRIX 0x3
56
57#define LPC32XX_KSCAN_IRQ_PENDING_CLR 0x1
58
59#define LPC32XX_KSCAN_SCTRL_SCAN_DELAY(n) ((n) & 0xFF)
60
61#define LPC32XX_KSCAN_FTST_FORCESCANONCE 0x1
62#define LPC32XX_KSCAN_FTST_USE32K_CLK 0x2
63
64#define LPC32XX_KSCAN_MSEL_SELECT(n) ((n) & 0xF)
65
66struct lpc32xx_kscan_drv {
67 struct input_dev *input;
68 struct clk *clk;
69 void __iomem *kscan_base;
70 unsigned int irq;
71
72 u32 matrix_sz; /* Size of matrix in XxY, ie. 3 = 3x3 */
73 u32 deb_clks; /* Debounce clocks (based on 32KHz clock) */
74 u32 scan_delay; /* Scan delay (based on 32KHz clock) */
75
76 unsigned short *keymap; /* Pointer to key map for the scan matrix */
77 unsigned int row_shift;
78
79 u8 lastkeystates[8];
80};
81
82static void lpc32xx_mod_states(struct lpc32xx_kscan_drv *kscandat, int col)
83{
84 struct input_dev *input = kscandat->input;
85 unsigned row, changed, scancode, keycode;
86 u8 key;
87
88 key = readl(LPC32XX_KS_DATA(kscandat->kscan_base, col));
89 changed = key ^ kscandat->lastkeystates[col];
90 kscandat->lastkeystates[col] = key;
91
92 for (row = 0; changed; row++, changed >>= 1) {
93 if (changed & 1) {
94 /* Key state changed, signal an event */
95 scancode = MATRIX_SCAN_CODE(row, col,
96 kscandat->row_shift);
97 keycode = kscandat->keymap[scancode];
98 input_event(input, EV_MSC, MSC_SCAN, scancode);
99 input_report_key(input, keycode, key & (1 << row));
100 }
101 }
102}
103
104static irqreturn_t lpc32xx_kscan_irq(int irq, void *dev_id)
105{
106 struct lpc32xx_kscan_drv *kscandat = dev_id;
107 int i;
108
109 for (i = 0; i < kscandat->matrix_sz; i++)
110 lpc32xx_mod_states(kscandat, i);
111
112 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
113
114 input_sync(kscandat->input);
115
116 return IRQ_HANDLED;
117}
118
119static int lpc32xx_kscan_open(struct input_dev *dev)
120{
121 struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
122 int error;
123
124 error = clk_prepare_enable(kscandat->clk);
125 if (error)
126 return error;
127
128 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
129
130 return 0;
131}
132
133static void lpc32xx_kscan_close(struct input_dev *dev)
134{
135 struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
136
137 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
138 clk_disable_unprepare(kscandat->clk);
139}
140
141static int lpc32xx_parse_dt(struct device *dev,
142 struct lpc32xx_kscan_drv *kscandat)
143{
144 struct device_node *np = dev->of_node;
145 u32 rows = 0, columns = 0;
146 int err;
147
148 err = matrix_keypad_parse_properties(dev, &rows, &columns);
149 if (err)
150 return err;
151 if (rows != columns) {
152 dev_err(dev, "rows and columns must be equal!\n");
153 return -EINVAL;
154 }
155
156 kscandat->matrix_sz = rows;
157 kscandat->row_shift = get_count_order(columns);
158
159 of_property_read_u32(np, "nxp,debounce-delay-ms", &kscandat->deb_clks);
160 of_property_read_u32(np, "nxp,scan-delay-ms", &kscandat->scan_delay);
161 if (!kscandat->deb_clks || !kscandat->scan_delay) {
162 dev_err(dev, "debounce or scan delay not specified\n");
163 return -EINVAL;
164 }
165
166 return 0;
167}
168
169static int lpc32xx_kscan_probe(struct platform_device *pdev)
170{
171 struct lpc32xx_kscan_drv *kscandat;
172 struct input_dev *input;
173 struct resource *res;
174 size_t keymap_size;
175 int error;
176 int irq;
177
178 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
179 if (!res) {
180 dev_err(&pdev->dev, "failed to get platform I/O memory\n");
181 return -EINVAL;
182 }
183
184 irq = platform_get_irq(pdev, 0);
185 if (irq < 0) {
186 dev_err(&pdev->dev, "failed to get platform irq\n");
187 return -EINVAL;
188 }
189
190 kscandat = devm_kzalloc(&pdev->dev, sizeof(*kscandat),
191 GFP_KERNEL);
192 if (!kscandat)
193 return -ENOMEM;
194
195 error = lpc32xx_parse_dt(&pdev->dev, kscandat);
196 if (error) {
197 dev_err(&pdev->dev, "failed to parse device tree\n");
198 return error;
199 }
200
201 keymap_size = sizeof(kscandat->keymap[0]) *
202 (kscandat->matrix_sz << kscandat->row_shift);
203 kscandat->keymap = devm_kzalloc(&pdev->dev, keymap_size, GFP_KERNEL);
204 if (!kscandat->keymap)
205 return -ENOMEM;
206
207 kscandat->input = input = devm_input_allocate_device(&pdev->dev);
208 if (!input) {
209 dev_err(&pdev->dev, "failed to allocate input device\n");
210 return -ENOMEM;
211 }
212
213 /* Setup key input */
214 input->name = pdev->name;
215 input->phys = "lpc32xx/input0";
216 input->id.vendor = 0x0001;
217 input->id.product = 0x0001;
218 input->id.version = 0x0100;
219 input->open = lpc32xx_kscan_open;
220 input->close = lpc32xx_kscan_close;
221 input->dev.parent = &pdev->dev;
222
223 input_set_capability(input, EV_MSC, MSC_SCAN);
224
225 error = matrix_keypad_build_keymap(NULL, NULL,
226 kscandat->matrix_sz,
227 kscandat->matrix_sz,
228 kscandat->keymap, kscandat->input);
229 if (error) {
230 dev_err(&pdev->dev, "failed to build keymap\n");
231 return error;
232 }
233
234 input_set_drvdata(kscandat->input, kscandat);
235
236 kscandat->kscan_base = devm_ioremap_resource(&pdev->dev, res);
237 if (IS_ERR(kscandat->kscan_base))
238 return PTR_ERR(kscandat->kscan_base);
239
240 /* Get the key scanner clock */
241 kscandat->clk = devm_clk_get(&pdev->dev, NULL);
242 if (IS_ERR(kscandat->clk)) {
243 dev_err(&pdev->dev, "failed to get clock\n");
244 return PTR_ERR(kscandat->clk);
245 }
246
247 /* Configure the key scanner */
248 error = clk_prepare_enable(kscandat->clk);
249 if (error)
250 return error;
251
252 writel(kscandat->deb_clks, LPC32XX_KS_DEB(kscandat->kscan_base));
253 writel(kscandat->scan_delay, LPC32XX_KS_SCAN_CTL(kscandat->kscan_base));
254 writel(LPC32XX_KSCAN_FTST_USE32K_CLK,
255 LPC32XX_KS_FAST_TST(kscandat->kscan_base));
256 writel(kscandat->matrix_sz,
257 LPC32XX_KS_MATRIX_DIM(kscandat->kscan_base));
258 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
259 clk_disable_unprepare(kscandat->clk);
260
261 error = devm_request_irq(&pdev->dev, irq, lpc32xx_kscan_irq, 0,
262 pdev->name, kscandat);
263 if (error) {
264 dev_err(&pdev->dev, "failed to request irq\n");
265 return error;
266 }
267
268 error = input_register_device(kscandat->input);
269 if (error) {
270 dev_err(&pdev->dev, "failed to register input device\n");
271 return error;
272 }
273
274 platform_set_drvdata(pdev, kscandat);
275
276 return 0;
277}
278
279#ifdef CONFIG_PM_SLEEP
280static int lpc32xx_kscan_suspend(struct device *dev)
281{
282 struct platform_device *pdev = to_platform_device(dev);
283 struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
284 struct input_dev *input = kscandat->input;
285
286 mutex_lock(&input->mutex);
287
288 if (input->users) {
289 /* Clear IRQ and disable clock */
290 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
291 clk_disable_unprepare(kscandat->clk);
292 }
293
294 mutex_unlock(&input->mutex);
295 return 0;
296}
297
298static int lpc32xx_kscan_resume(struct device *dev)
299{
300 struct platform_device *pdev = to_platform_device(dev);
301 struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
302 struct input_dev *input = kscandat->input;
303 int retval = 0;
304
305 mutex_lock(&input->mutex);
306
307 if (input->users) {
308 /* Enable clock and clear IRQ */
309 retval = clk_prepare_enable(kscandat->clk);
310 if (retval == 0)
311 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
312 }
313
314 mutex_unlock(&input->mutex);
315 return retval;
316}
317#endif
318
319static SIMPLE_DEV_PM_OPS(lpc32xx_kscan_pm_ops, lpc32xx_kscan_suspend,
320 lpc32xx_kscan_resume);
321
322static const struct of_device_id lpc32xx_kscan_match[] = {
323 { .compatible = "nxp,lpc3220-key" },
324 {},
325};
326MODULE_DEVICE_TABLE(of, lpc32xx_kscan_match);
327
328static struct platform_driver lpc32xx_kscan_driver = {
329 .probe = lpc32xx_kscan_probe,
330 .driver = {
331 .name = DRV_NAME,
332 .pm = &lpc32xx_kscan_pm_ops,
333 .of_match_table = lpc32xx_kscan_match,
334 }
335};
336
337module_platform_driver(lpc32xx_kscan_driver);
338
339MODULE_LICENSE("GPL");
340MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
341MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
342MODULE_DESCRIPTION("Key scanner driver for LPC32XX devices");
343

Warning: That file was not part of the compilation database. It may have many parsing errors.