1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for the enhanced rotary controller on pxa930 and pxa935
4 */
5
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/interrupt.h>
9 #include <linux/input.h>
10 #include <linux/platform_device.h>
11 #include <linux/io.h>
12 #include <linux/slab.h>
13
14 #include <linux/platform_data/keyboard-pxa930_rotary.h>
15
16 #define SBCR (0x04)
17 #define ERCR (0x0c)
18
19 #define SBCR_ERSB (1 << 5)
20
21 struct pxa930_rotary {
22 struct input_dev *input_dev;
23 void __iomem *mmio_base;
24 int last_ercr;
25
26 struct pxa930_rotary_platform_data *pdata;
27 };
28
clear_sbcr(struct pxa930_rotary * r)29 static void clear_sbcr(struct pxa930_rotary *r)
30 {
31 uint32_t sbcr = __raw_readl(r->mmio_base + SBCR);
32
33 __raw_writel(sbcr | SBCR_ERSB, r->mmio_base + SBCR);
34 __raw_writel(sbcr & ~SBCR_ERSB, r->mmio_base + SBCR);
35 }
36
rotary_irq(int irq,void * dev_id)37 static irqreturn_t rotary_irq(int irq, void *dev_id)
38 {
39 struct pxa930_rotary *r = dev_id;
40 struct pxa930_rotary_platform_data *pdata = r->pdata;
41 int ercr, delta, key;
42
43 ercr = __raw_readl(r->mmio_base + ERCR) & 0xf;
44 clear_sbcr(r);
45
46 delta = ercr - r->last_ercr;
47 if (delta == 0)
48 return IRQ_HANDLED;
49
50 r->last_ercr = ercr;
51
52 if (pdata->up_key && pdata->down_key) {
53 key = (delta > 0) ? pdata->up_key : pdata->down_key;
54 input_report_key(r->input_dev, key, 1);
55 input_sync(r->input_dev);
56 input_report_key(r->input_dev, key, 0);
57 } else
58 input_report_rel(r->input_dev, pdata->rel_code, delta);
59
60 input_sync(r->input_dev);
61
62 return IRQ_HANDLED;
63 }
64
pxa930_rotary_open(struct input_dev * dev)65 static int pxa930_rotary_open(struct input_dev *dev)
66 {
67 struct pxa930_rotary *r = input_get_drvdata(dev);
68
69 clear_sbcr(r);
70
71 return 0;
72 }
73
pxa930_rotary_close(struct input_dev * dev)74 static void pxa930_rotary_close(struct input_dev *dev)
75 {
76 struct pxa930_rotary *r = input_get_drvdata(dev);
77
78 clear_sbcr(r);
79 }
80
pxa930_rotary_probe(struct platform_device * pdev)81 static int pxa930_rotary_probe(struct platform_device *pdev)
82 {
83 struct pxa930_rotary_platform_data *pdata =
84 dev_get_platdata(&pdev->dev);
85 struct pxa930_rotary *r;
86 struct input_dev *input_dev;
87 struct resource *res;
88 int irq;
89 int err;
90
91 irq = platform_get_irq(pdev, 0);
92 if (irq < 0)
93 return -ENXIO;
94
95 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
96 if (!res) {
97 dev_err(&pdev->dev, "no I/O memory defined\n");
98 return -ENXIO;
99 }
100
101 if (!pdata) {
102 dev_err(&pdev->dev, "no platform data defined\n");
103 return -EINVAL;
104 }
105
106 r = kzalloc(sizeof(struct pxa930_rotary), GFP_KERNEL);
107 if (!r)
108 return -ENOMEM;
109
110 r->mmio_base = ioremap(res->start, resource_size(res));
111 if (r->mmio_base == NULL) {
112 dev_err(&pdev->dev, "failed to remap IO memory\n");
113 err = -ENXIO;
114 goto failed_free;
115 }
116
117 r->pdata = pdata;
118 platform_set_drvdata(pdev, r);
119
120 /* allocate and register the input device */
121 input_dev = input_allocate_device();
122 if (!input_dev) {
123 dev_err(&pdev->dev, "failed to allocate input device\n");
124 err = -ENOMEM;
125 goto failed_free_io;
126 }
127
128 input_dev->name = pdev->name;
129 input_dev->id.bustype = BUS_HOST;
130 input_dev->open = pxa930_rotary_open;
131 input_dev->close = pxa930_rotary_close;
132 input_dev->dev.parent = &pdev->dev;
133
134 if (pdata->up_key && pdata->down_key) {
135 __set_bit(pdata->up_key, input_dev->keybit);
136 __set_bit(pdata->down_key, input_dev->keybit);
137 __set_bit(EV_KEY, input_dev->evbit);
138 } else {
139 __set_bit(pdata->rel_code, input_dev->relbit);
140 __set_bit(EV_REL, input_dev->evbit);
141 }
142
143 r->input_dev = input_dev;
144 input_set_drvdata(input_dev, r);
145
146 err = request_irq(irq, rotary_irq, 0,
147 "enhanced rotary", r);
148 if (err) {
149 dev_err(&pdev->dev, "failed to request IRQ\n");
150 goto failed_free_input;
151 }
152
153 err = input_register_device(input_dev);
154 if (err) {
155 dev_err(&pdev->dev, "failed to register input device\n");
156 goto failed_free_irq;
157 }
158
159 return 0;
160
161 failed_free_irq:
162 free_irq(irq, r);
163 failed_free_input:
164 input_free_device(input_dev);
165 failed_free_io:
166 iounmap(r->mmio_base);
167 failed_free:
168 kfree(r);
169 return err;
170 }
171
pxa930_rotary_remove(struct platform_device * pdev)172 static int pxa930_rotary_remove(struct platform_device *pdev)
173 {
174 struct pxa930_rotary *r = platform_get_drvdata(pdev);
175
176 free_irq(platform_get_irq(pdev, 0), r);
177 input_unregister_device(r->input_dev);
178 iounmap(r->mmio_base);
179 kfree(r);
180
181 return 0;
182 }
183
184 static struct platform_driver pxa930_rotary_driver = {
185 .driver = {
186 .name = "pxa930-rotary",
187 },
188 .probe = pxa930_rotary_probe,
189 .remove = pxa930_rotary_remove,
190 };
191 module_platform_driver(pxa930_rotary_driver);
192
193 MODULE_LICENSE("GPL");
194 MODULE_DESCRIPTION("Driver for PXA93x Enhanced Rotary Controller");
195 MODULE_AUTHOR("Yao Yong <yaoyong@marvell.com>");
196