1 /*
2 * Driver for the enhanced rotary controller on pxa930 and pxa935
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/interrupt.h>
12 #include <linux/input.h>
13 #include <linux/platform_device.h>
14 #include <linux/io.h>
15 #include <linux/slab.h>
16
17 #include <linux/platform_data/keyboard-pxa930_rotary.h>
18
19 #define SBCR (0x04)
20 #define ERCR (0x0c)
21
22 #define SBCR_ERSB (1 << 5)
23
24 struct pxa930_rotary {
25 struct input_dev *input_dev;
26 void __iomem *mmio_base;
27 int last_ercr;
28
29 struct pxa930_rotary_platform_data *pdata;
30 };
31
clear_sbcr(struct pxa930_rotary * r)32 static void clear_sbcr(struct pxa930_rotary *r)
33 {
34 uint32_t sbcr = __raw_readl(r->mmio_base + SBCR);
35
36 __raw_writel(sbcr | SBCR_ERSB, r->mmio_base + SBCR);
37 __raw_writel(sbcr & ~SBCR_ERSB, r->mmio_base + SBCR);
38 }
39
rotary_irq(int irq,void * dev_id)40 static irqreturn_t rotary_irq(int irq, void *dev_id)
41 {
42 struct pxa930_rotary *r = dev_id;
43 struct pxa930_rotary_platform_data *pdata = r->pdata;
44 int ercr, delta, key;
45
46 ercr = __raw_readl(r->mmio_base + ERCR) & 0xf;
47 clear_sbcr(r);
48
49 delta = ercr - r->last_ercr;
50 if (delta == 0)
51 return IRQ_HANDLED;
52
53 r->last_ercr = ercr;
54
55 if (pdata->up_key && pdata->down_key) {
56 key = (delta > 0) ? pdata->up_key : pdata->down_key;
57 input_report_key(r->input_dev, key, 1);
58 input_sync(r->input_dev);
59 input_report_key(r->input_dev, key, 0);
60 } else
61 input_report_rel(r->input_dev, pdata->rel_code, delta);
62
63 input_sync(r->input_dev);
64
65 return IRQ_HANDLED;
66 }
67
pxa930_rotary_open(struct input_dev * dev)68 static int pxa930_rotary_open(struct input_dev *dev)
69 {
70 struct pxa930_rotary *r = input_get_drvdata(dev);
71
72 clear_sbcr(r);
73
74 return 0;
75 }
76
pxa930_rotary_close(struct input_dev * dev)77 static void pxa930_rotary_close(struct input_dev *dev)
78 {
79 struct pxa930_rotary *r = input_get_drvdata(dev);
80
81 clear_sbcr(r);
82 }
83
pxa930_rotary_probe(struct platform_device * pdev)84 static int pxa930_rotary_probe(struct platform_device *pdev)
85 {
86 struct pxa930_rotary_platform_data *pdata =
87 dev_get_platdata(&pdev->dev);
88 struct pxa930_rotary *r;
89 struct input_dev *input_dev;
90 struct resource *res;
91 int irq;
92 int err;
93
94 irq = platform_get_irq(pdev, 0);
95 if (irq < 0) {
96 dev_err(&pdev->dev, "no irq for rotary controller\n");
97 return -ENXIO;
98 }
99
100 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
101 if (!res) {
102 dev_err(&pdev->dev, "no I/O memory defined\n");
103 return -ENXIO;
104 }
105
106 if (!pdata) {
107 dev_err(&pdev->dev, "no platform data defined\n");
108 return -EINVAL;
109 }
110
111 r = kzalloc(sizeof(struct pxa930_rotary), GFP_KERNEL);
112 if (!r)
113 return -ENOMEM;
114
115 r->mmio_base = ioremap_nocache(res->start, resource_size(res));
116 if (r->mmio_base == NULL) {
117 dev_err(&pdev->dev, "failed to remap IO memory\n");
118 err = -ENXIO;
119 goto failed_free;
120 }
121
122 r->pdata = pdata;
123 platform_set_drvdata(pdev, r);
124
125 /* allocate and register the input device */
126 input_dev = input_allocate_device();
127 if (!input_dev) {
128 dev_err(&pdev->dev, "failed to allocate input device\n");
129 err = -ENOMEM;
130 goto failed_free_io;
131 }
132
133 input_dev->name = pdev->name;
134 input_dev->id.bustype = BUS_HOST;
135 input_dev->open = pxa930_rotary_open;
136 input_dev->close = pxa930_rotary_close;
137 input_dev->dev.parent = &pdev->dev;
138
139 if (pdata->up_key && pdata->down_key) {
140 __set_bit(pdata->up_key, input_dev->keybit);
141 __set_bit(pdata->down_key, input_dev->keybit);
142 __set_bit(EV_KEY, input_dev->evbit);
143 } else {
144 __set_bit(pdata->rel_code, input_dev->relbit);
145 __set_bit(EV_REL, input_dev->evbit);
146 }
147
148 r->input_dev = input_dev;
149 input_set_drvdata(input_dev, r);
150
151 err = request_irq(irq, rotary_irq, 0,
152 "enhanced rotary", r);
153 if (err) {
154 dev_err(&pdev->dev, "failed to request IRQ\n");
155 goto failed_free_input;
156 }
157
158 err = input_register_device(input_dev);
159 if (err) {
160 dev_err(&pdev->dev, "failed to register input device\n");
161 goto failed_free_irq;
162 }
163
164 return 0;
165
166 failed_free_irq:
167 free_irq(irq, r);
168 failed_free_input:
169 input_free_device(input_dev);
170 failed_free_io:
171 iounmap(r->mmio_base);
172 failed_free:
173 kfree(r);
174 return err;
175 }
176
pxa930_rotary_remove(struct platform_device * pdev)177 static int pxa930_rotary_remove(struct platform_device *pdev)
178 {
179 struct pxa930_rotary *r = platform_get_drvdata(pdev);
180
181 free_irq(platform_get_irq(pdev, 0), r);
182 input_unregister_device(r->input_dev);
183 iounmap(r->mmio_base);
184 kfree(r);
185
186 return 0;
187 }
188
189 static struct platform_driver pxa930_rotary_driver = {
190 .driver = {
191 .name = "pxa930-rotary",
192 },
193 .probe = pxa930_rotary_probe,
194 .remove = pxa930_rotary_remove,
195 };
196 module_platform_driver(pxa930_rotary_driver);
197
198 MODULE_LICENSE("GPL");
199 MODULE_DESCRIPTION("Driver for PXA93x Enhanced Rotary Controller");
200 MODULE_AUTHOR("Yao Yong <yaoyong@marvell.com>");
201