Input: w90p910_keypad - move a dereference below a NULL test
[deliverable/linux.git] / drivers / input / keyboard / w90p910_keypad.c
1 /*
2 * Copyright (c) 2008-2009 Nuvoton technology corporation.
3 *
4 * Wan ZongShun <mcuos.com@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation;version 2 of the License.
9 *
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/input.h>
17 #include <linux/device.h>
18 #include <linux/platform_device.h>
19 #include <linux/clk.h>
20 #include <linux/err.h>
21 #include <linux/io.h>
22
23 #include <mach/w90p910_keypad.h>
24
25 /* Keypad Interface Control Registers */
26 #define KPI_CONF 0x00
27 #define KPI_3KCONF 0x04
28 #define KPI_LPCONF 0x08
29 #define KPI_STATUS 0x0C
30
31 #define IS1KEY (0x01 << 16)
32 #define INTTR (0x01 << 21)
33 #define KEY0R (0x0f << 3)
34 #define KEY0C 0x07
35 #define DEBOUNCE_BIT 0x08
36 #define KSIZE0 (0x01 << 16)
37 #define KSIZE1 (0x01 << 17)
38 #define KPSEL (0x01 << 19)
39 #define ENKP (0x01 << 18)
40
41 #define KGET_RAW(n) (((n) & KEY0R) >> 3)
42 #define KGET_COLUMN(n) ((n) & KEY0C)
43
44 #define W90P910_MAX_KEY_NUM (8 * 8)
45 #define W90P910_ROW_SHIFT 3
46
47 struct w90p910_keypad {
48 const struct w90p910_keypad_platform_data *pdata;
49 struct clk *clk;
50 struct input_dev *input_dev;
51 void __iomem *mmio_base;
52 int irq;
53 unsigned short keymap[W90P910_MAX_KEY_NUM];
54 };
55
56 static void w90p910_keypad_scan_matrix(struct w90p910_keypad *keypad,
57 unsigned int status)
58 {
59 struct input_dev *input_dev = keypad->input_dev;
60 unsigned int row = KGET_RAW(status);
61 unsigned int col = KGET_COLUMN(status);
62 unsigned int code = MATRIX_SCAN_CODE(row, col, W90P910_ROW_SHIFT);
63 unsigned int key = keypad->keymap[code];
64
65 input_event(input_dev, EV_MSC, MSC_SCAN, code);
66 input_report_key(input_dev, key, 1);
67 input_sync(input_dev);
68
69 input_event(input_dev, EV_MSC, MSC_SCAN, code);
70 input_report_key(input_dev, key, 0);
71 input_sync(input_dev);
72 }
73
74 static irqreturn_t w90p910_keypad_irq_handler(int irq, void *dev_id)
75 {
76 struct w90p910_keypad *keypad = dev_id;
77 unsigned int kstatus, val;
78
79 kstatus = __raw_readl(keypad->mmio_base + KPI_STATUS);
80
81 val = INTTR | IS1KEY;
82
83 if (kstatus & val)
84 w90p910_keypad_scan_matrix(keypad, kstatus);
85
86 return IRQ_HANDLED;
87 }
88
89 static int w90p910_keypad_open(struct input_dev *dev)
90 {
91 struct w90p910_keypad *keypad = input_get_drvdata(dev);
92 const struct w90p910_keypad_platform_data *pdata = keypad->pdata;
93 unsigned int val, config;
94
95 /* Enable unit clock */
96 clk_enable(keypad->clk);
97
98 val = __raw_readl(keypad->mmio_base + KPI_CONF);
99 val |= (KPSEL | ENKP);
100 val &= ~(KSIZE0 | KSIZE1);
101
102 config = pdata->prescale | (pdata->debounce << DEBOUNCE_BIT);
103
104 val |= config;
105
106 __raw_writel(val, keypad->mmio_base + KPI_CONF);
107
108 return 0;
109 }
110
111 static void w90p910_keypad_close(struct input_dev *dev)
112 {
113 struct w90p910_keypad *keypad = input_get_drvdata(dev);
114
115 /* Disable clock unit */
116 clk_disable(keypad->clk);
117 }
118
119 static int __devinit w90p910_keypad_probe(struct platform_device *pdev)
120 {
121 const struct w90p910_keypad_platform_data *pdata =
122 pdev->dev.platform_data;
123 const struct matrix_keymap_data *keymap_data;
124 struct w90p910_keypad *keypad;
125 struct input_dev *input_dev;
126 struct resource *res;
127 int irq;
128 int error;
129
130 if (!pdata) {
131 dev_err(&pdev->dev, "no platform data defined\n");
132 return -EINVAL;
133 }
134
135 keymap_data = pdata->keymap_data;
136
137 irq = platform_get_irq(pdev, 0);
138 if (irq < 0) {
139 dev_err(&pdev->dev, "failed to get keypad irq\n");
140 return -ENXIO;
141 }
142
143 keypad = kzalloc(sizeof(struct w90p910_keypad), GFP_KERNEL);
144 input_dev = input_allocate_device();
145 if (!keypad || !input_dev) {
146 dev_err(&pdev->dev, "failed to allocate driver data\n");
147 error = -ENOMEM;
148 goto failed_free;
149 }
150
151 keypad->pdata = pdata;
152 keypad->input_dev = input_dev;
153 keypad->irq = irq;
154
155 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
156 if (res == NULL) {
157 dev_err(&pdev->dev, "failed to get I/O memory\n");
158 error = -ENXIO;
159 goto failed_free;
160 }
161
162 res = request_mem_region(res->start, resource_size(res), pdev->name);
163 if (res == NULL) {
164 dev_err(&pdev->dev, "failed to request I/O memory\n");
165 error = -EBUSY;
166 goto failed_free;
167 }
168
169 keypad->mmio_base = ioremap(res->start, resource_size(res));
170 if (keypad->mmio_base == NULL) {
171 dev_err(&pdev->dev, "failed to remap I/O memory\n");
172 error = -ENXIO;
173 goto failed_free_res;
174 }
175
176 keypad->clk = clk_get(&pdev->dev, NULL);
177 if (IS_ERR(keypad->clk)) {
178 dev_err(&pdev->dev, "failed to get keypad clock\n");
179 error = PTR_ERR(keypad->clk);
180 goto failed_free_io;
181 }
182
183 /* set multi-function pin for w90p910 kpi. */
184 mfp_set_groupi(&pdev->dev);
185
186 input_dev->name = pdev->name;
187 input_dev->id.bustype = BUS_HOST;
188 input_dev->open = w90p910_keypad_open;
189 input_dev->close = w90p910_keypad_close;
190 input_dev->dev.parent = &pdev->dev;
191
192 input_dev->keycode = keypad->keymap;
193 input_dev->keycodesize = sizeof(keypad->keymap[0]);
194 input_dev->keycodemax = ARRAY_SIZE(keypad->keymap);
195
196 input_set_drvdata(input_dev, keypad);
197
198 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
199 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
200
201 matrix_keypad_build_keymap(keymap_data, W90P910_ROW_SHIFT,
202 input_dev->keycode, input_dev->keybit);
203
204 error = request_irq(keypad->irq, w90p910_keypad_irq_handler,
205 IRQF_DISABLED, pdev->name, keypad);
206 if (error) {
207 dev_err(&pdev->dev, "failed to request IRQ\n");
208 goto failed_put_clk;
209 }
210
211 /* Register the input device */
212 error = input_register_device(input_dev);
213 if (error) {
214 dev_err(&pdev->dev, "failed to register input device\n");
215 goto failed_free_irq;
216 }
217
218 platform_set_drvdata(pdev, keypad);
219 return 0;
220
221 failed_free_irq:
222 free_irq(irq, pdev);
223 failed_put_clk:
224 clk_put(keypad->clk);
225 failed_free_io:
226 iounmap(keypad->mmio_base);
227 failed_free_res:
228 release_mem_region(res->start, resource_size(res));
229 failed_free:
230 input_free_device(input_dev);
231 kfree(keypad);
232 return error;
233 }
234
235 static int __devexit w90p910_keypad_remove(struct platform_device *pdev)
236 {
237 struct w90p910_keypad *keypad = platform_get_drvdata(pdev);
238 struct resource *res;
239
240 free_irq(keypad->irq, pdev);
241
242 clk_put(keypad->clk);
243
244 input_unregister_device(keypad->input_dev);
245
246 iounmap(keypad->mmio_base);
247 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
248 release_mem_region(res->start, resource_size(res));
249
250 platform_set_drvdata(pdev, NULL);
251 kfree(keypad);
252
253 return 0;
254 }
255
256 static struct platform_driver w90p910_keypad_driver = {
257 .probe = w90p910_keypad_probe,
258 .remove = __devexit_p(w90p910_keypad_remove),
259 .driver = {
260 .name = "nuc900-keypad",
261 .owner = THIS_MODULE,
262 },
263 };
264
265 static int __init w90p910_keypad_init(void)
266 {
267 return platform_driver_register(&w90p910_keypad_driver);
268 }
269
270 static void __exit w90p910_keypad_exit(void)
271 {
272 platform_driver_unregister(&w90p910_keypad_driver);
273 }
274
275 module_init(w90p910_keypad_init);
276 module_exit(w90p910_keypad_exit);
277
278 MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
279 MODULE_DESCRIPTION("w90p910 keypad driver");
280 MODULE_LICENSE("GPL");
281 MODULE_ALIAS("platform:nuc900-keypad");
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