1 /*
2 * PXA930 track ball mouse driver
3 *
4 * Copyright (C) 2007 Marvell International Ltd.
5 * 2008-02-28: Yong Yao <yaoyong@marvell.com>
6 * initial version
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13 #include <linux/init.h>
14 #include <linux/input.h>
15 #include <linux/interrupt.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/delay.h>
19 #include <linux/io.h>
20 #include <linux/slab.h>
21
22 #include <mach/hardware.h>
23 #include <mach/pxa930_trkball.h>
24
25 /* Trackball Controller Register Definitions */
26 #define TBCR (0x000C)
27 #define TBCNTR (0x0010)
28 #define TBSBC (0x0014)
29
30 #define TBCR_TBRST (1 << 1)
31 #define TBCR_TBSB (1 << 10)
32
33 #define TBCR_Y_FLT(n) (((n) & 0xf) << 6)
34 #define TBCR_X_FLT(n) (((n) & 0xf) << 2)
35
36 #define TBCNTR_YM(n) (((n) >> 24) & 0xff)
37 #define TBCNTR_YP(n) (((n) >> 16) & 0xff)
38 #define TBCNTR_XM(n) (((n) >> 8) & 0xff)
39 #define TBCNTR_XP(n) ((n) & 0xff)
40
41 #define TBSBC_TBSBC (0x1)
42
43 struct pxa930_trkball {
44 struct pxa930_trkball_platform_data *pdata;
45
46 /* Memory Mapped Register */
47 struct resource *mem;
48 void __iomem *mmio_base;
49
50 struct input_dev *input;
51 };
52
pxa930_trkball_interrupt(int irq,void * dev_id)53 static irqreturn_t pxa930_trkball_interrupt(int irq, void *dev_id)
54 {
55 struct pxa930_trkball *trkball = dev_id;
56 struct input_dev *input = trkball->input;
57 int tbcntr, x, y;
58
59 /* According to the spec software must read TBCNTR twice:
60 * if the read value is the same, the reading is valid
61 */
62 tbcntr = __raw_readl(trkball->mmio_base + TBCNTR);
63
64 if (tbcntr == __raw_readl(trkball->mmio_base + TBCNTR)) {
65 x = (TBCNTR_XP(tbcntr) - TBCNTR_XM(tbcntr)) / 2;
66 y = (TBCNTR_YP(tbcntr) - TBCNTR_YM(tbcntr)) / 2;
67
68 input_report_rel(input, REL_X, x);
69 input_report_rel(input, REL_Y, y);
70 input_sync(input);
71 }
72
73 __raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
74 __raw_writel(0, trkball->mmio_base + TBSBC);
75
76 return IRQ_HANDLED;
77 }
78
79 /* For TBCR, we need to wait for a while to make sure it has been modified. */
write_tbcr(struct pxa930_trkball * trkball,int v)80 static int write_tbcr(struct pxa930_trkball *trkball, int v)
81 {
82 int i = 100;
83
84 __raw_writel(v, trkball->mmio_base + TBCR);
85
86 while (--i) {
87 if (__raw_readl(trkball->mmio_base + TBCR) == v)
88 break;
89 msleep(1);
90 }
91
92 if (i == 0) {
93 pr_err("%s: timed out writing TBCR(%x)!\n", __func__, v);
94 return -ETIMEDOUT;
95 }
96
97 return 0;
98 }
99
pxa930_trkball_config(struct pxa930_trkball * trkball)100 static void pxa930_trkball_config(struct pxa930_trkball *trkball)
101 {
102 uint32_t tbcr;
103
104 /* According to spec, need to write the filters of x,y to 0xf first! */
105 tbcr = __raw_readl(trkball->mmio_base + TBCR);
106 write_tbcr(trkball, tbcr | TBCR_X_FLT(0xf) | TBCR_Y_FLT(0xf));
107 write_tbcr(trkball, TBCR_X_FLT(trkball->pdata->x_filter) |
108 TBCR_Y_FLT(trkball->pdata->y_filter));
109
110 /* According to spec, set TBCR_TBRST first, before clearing it! */
111 tbcr = __raw_readl(trkball->mmio_base + TBCR);
112 write_tbcr(trkball, tbcr | TBCR_TBRST);
113 write_tbcr(trkball, tbcr & ~TBCR_TBRST);
114
115 __raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
116 __raw_writel(0, trkball->mmio_base + TBSBC);
117
118 pr_debug("%s: final TBCR=%x!\n", __func__,
119 __raw_readl(trkball->mmio_base + TBCR));
120 }
121
pxa930_trkball_open(struct input_dev * dev)122 static int pxa930_trkball_open(struct input_dev *dev)
123 {
124 struct pxa930_trkball *trkball = input_get_drvdata(dev);
125
126 pxa930_trkball_config(trkball);
127
128 return 0;
129 }
130
pxa930_trkball_disable(struct pxa930_trkball * trkball)131 static void pxa930_trkball_disable(struct pxa930_trkball *trkball)
132 {
133 uint32_t tbcr = __raw_readl(trkball->mmio_base + TBCR);
134
135 /* Held in reset, gate the 32-KHz input clock off */
136 write_tbcr(trkball, tbcr | TBCR_TBRST);
137 }
138
pxa930_trkball_close(struct input_dev * dev)139 static void pxa930_trkball_close(struct input_dev *dev)
140 {
141 struct pxa930_trkball *trkball = input_get_drvdata(dev);
142
143 pxa930_trkball_disable(trkball);
144 }
145
pxa930_trkball_probe(struct platform_device * pdev)146 static int __devinit pxa930_trkball_probe(struct platform_device *pdev)
147 {
148 struct pxa930_trkball *trkball;
149 struct input_dev *input;
150 struct resource *res;
151 int irq, error;
152
153 irq = platform_get_irq(pdev, 0);
154 if (irq < 0) {
155 dev_err(&pdev->dev, "failed to get trkball irq\n");
156 return -ENXIO;
157 }
158
159 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
160 if (!res) {
161 dev_err(&pdev->dev, "failed to get register memory\n");
162 return -ENXIO;
163 }
164
165 trkball = kzalloc(sizeof(struct pxa930_trkball), GFP_KERNEL);
166 if (!trkball)
167 return -ENOMEM;
168
169 trkball->pdata = pdev->dev.platform_data;
170 if (!trkball->pdata) {
171 dev_err(&pdev->dev, "no platform data defined\n");
172 error = -EINVAL;
173 goto failed;
174 }
175
176 trkball->mmio_base = ioremap_nocache(res->start, resource_size(res));
177 if (!trkball->mmio_base) {
178 dev_err(&pdev->dev, "failed to ioremap registers\n");
179 error = -ENXIO;
180 goto failed;
181 }
182
183 /* held the module in reset, will be enabled in open() */
184 pxa930_trkball_disable(trkball);
185
186 error = request_irq(irq, pxa930_trkball_interrupt, 0,
187 pdev->name, trkball);
188 if (error) {
189 dev_err(&pdev->dev, "failed to request irq: %d\n", error);
190 goto failed_free_io;
191 }
192
193 platform_set_drvdata(pdev, trkball);
194
195 input = input_allocate_device();
196 if (!input) {
197 dev_err(&pdev->dev, "failed to allocate input device\n");
198 error = -ENOMEM;
199 goto failed_free_irq;
200 }
201
202 input->name = pdev->name;
203 input->id.bustype = BUS_HOST;
204 input->open = pxa930_trkball_open;
205 input->close = pxa930_trkball_close;
206 input->dev.parent = &pdev->dev;
207 input_set_drvdata(input, trkball);
208
209 trkball->input = input;
210
211 input_set_capability(input, EV_REL, REL_X);
212 input_set_capability(input, EV_REL, REL_Y);
213
214 error = input_register_device(input);
215 if (error) {
216 dev_err(&pdev->dev, "unable to register input device\n");
217 goto failed_free_input;
218 }
219
220 return 0;
221
222 failed_free_input:
223 input_free_device(input);
224 failed_free_irq:
225 free_irq(irq, trkball);
226 failed_free_io:
227 iounmap(trkball->mmio_base);
228 failed:
229 kfree(trkball);
230 return error;
231 }
232
pxa930_trkball_remove(struct platform_device * pdev)233 static int __devexit pxa930_trkball_remove(struct platform_device *pdev)
234 {
235 struct pxa930_trkball *trkball = platform_get_drvdata(pdev);
236 int irq = platform_get_irq(pdev, 0);
237
238 input_unregister_device(trkball->input);
239 free_irq(irq, trkball);
240 iounmap(trkball->mmio_base);
241 kfree(trkball);
242
243 return 0;
244 }
245
246 static struct platform_driver pxa930_trkball_driver = {
247 .driver = {
248 .name = "pxa930-trkball",
249 },
250 .probe = pxa930_trkball_probe,
251 .remove = __devexit_p(pxa930_trkball_remove),
252 };
253 module_platform_driver(pxa930_trkball_driver);
254
255 MODULE_AUTHOR("Yong Yao <yaoyong@marvell.com>");
256 MODULE_DESCRIPTION("PXA930 Trackball Mouse Driver");
257 MODULE_LICENSE("GPL");
258