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
24struct 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
32static 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
40static 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
68static 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
77static 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
84static 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
166failed_free_irq:
167	free_irq(irq, r);
168failed_free_input:
169	input_free_device(input_dev);
170failed_free_io:
171	iounmap(r->mmio_base);
172failed_free:
173	kfree(r);
174	return err;
175}
176
177static 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
189static struct platform_driver pxa930_rotary_driver = {
190	.driver		= {
191		.name	= "pxa930-rotary",
192	},
193	.probe		= pxa930_rotary_probe,
194	.remove		= pxa930_rotary_remove,
195};
196module_platform_driver(pxa930_rotary_driver);
197
198MODULE_LICENSE("GPL");
199MODULE_DESCRIPTION("Driver for PXA93x Enhanced Rotary Controller");
200MODULE_AUTHOR("Yao Yong <yaoyong@marvell.com>");
201