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1/*
2 * Amstrad E3 (Delta) keyboard port driver
3 *
4 * Copyright (c) 2006 Matt Callow
5 * Copyright (c) 2010 Janusz Krzysztofik
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation.
10 *
11 * Thanks to Cliff Lawson for his help
12 *
13 * The Amstrad Delta keyboard (aka mailboard) uses normal PC-AT style serial
14 * transmission. The keyboard port is formed of two GPIO lines, for clock
15 * and data. Due to strict timing requirements of the interface,
16 * the serial data stream is read and processed by a FIQ handler.
17 * The resulting words are fetched by this driver from a circular buffer.
18 *
19 * Standard AT keyboard driver (atkbd) is used for handling the keyboard data.
20 * However, when used with the E3 mailboard that producecs non-standard
21 * scancodes, a custom key table must be prepared and loaded from userspace.
22 */
23#include <linux/irq.h>
24#include <linux/platform_data/ams-delta-fiq.h>
25#include <linux/platform_device.h>
26#include <linux/regulator/consumer.h>
27#include <linux/serio.h>
28#include <linux/slab.h>
29#include <linux/module.h>
30
31#define DRIVER_NAME "ams-delta-serio"
32
33MODULE_AUTHOR("Matt Callow");
34MODULE_DESCRIPTION("AMS Delta (E3) keyboard port driver");
35MODULE_LICENSE("GPL");
36
37struct ams_delta_serio {
38 struct serio *serio;
39 struct regulator *vcc;
40 unsigned int *fiq_buffer;
41};
42
43static int check_data(struct serio *serio, int data)
44{
45 int i, parity = 0;
46
47 /* check valid stop bit */
48 if (!(data & 0x400)) {
49 dev_warn(&serio->dev, "invalid stop bit, data=0x%X\n", data);
50 return SERIO_FRAME;
51 }
52 /* calculate the parity */
53 for (i = 1; i < 10; i++) {
54 if (data & (1 << i))
55 parity++;
56 }
57 /* it should be odd */
58 if (!(parity & 0x01)) {
59 dev_warn(&serio->dev,
60 "parity check failed, data=0x%X parity=0x%X\n", data,
61 parity);
62 return SERIO_PARITY;
63 }
64 return 0;
65}
66
67static irqreturn_t ams_delta_serio_interrupt(int irq, void *dev_id)
68{
69 struct ams_delta_serio *priv = dev_id;
70 int *circ_buff = &priv->fiq_buffer[FIQ_CIRC_BUFF];
71 int data, dfl;
72 u8 scancode;
73
74 priv->fiq_buffer[FIQ_IRQ_PEND] = 0;
75
76 /*
77 * Read data from the circular buffer, check it
78 * and then pass it on the serio
79 */
80 while (priv->fiq_buffer[FIQ_KEYS_CNT] > 0) {
81
82 data = circ_buff[priv->fiq_buffer[FIQ_HEAD_OFFSET]++];
83 priv->fiq_buffer[FIQ_KEYS_CNT]--;
84 if (priv->fiq_buffer[FIQ_HEAD_OFFSET] ==
85 priv->fiq_buffer[FIQ_BUF_LEN])
86 priv->fiq_buffer[FIQ_HEAD_OFFSET] = 0;
87
88 dfl = check_data(priv->serio, data);
89 scancode = (u8) (data >> 1) & 0xFF;
90 serio_interrupt(priv->serio, scancode, dfl);
91 }
92 return IRQ_HANDLED;
93}
94
95static int ams_delta_serio_open(struct serio *serio)
96{
97 struct ams_delta_serio *priv = serio->port_data;
98
99 /* enable keyboard */
100 return regulator_enable(priv->vcc);
101}
102
103static void ams_delta_serio_close(struct serio *serio)
104{
105 struct ams_delta_serio *priv = serio->port_data;
106
107 /* disable keyboard */
108 regulator_disable(priv->vcc);
109}
110
111static int ams_delta_serio_init(struct platform_device *pdev)
112{
113 struct ams_delta_serio *priv;
114 struct serio *serio;
115 int irq, err;
116
117 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
118 if (!priv)
119 return -ENOMEM;
120
121 priv->fiq_buffer = pdev->dev.platform_data;
122 if (!priv->fiq_buffer)
123 return -EINVAL;
124
125 priv->vcc = devm_regulator_get(&pdev->dev, "vcc");
126 if (IS_ERR(priv->vcc)) {
127 err = PTR_ERR(priv->vcc);
128 dev_err(&pdev->dev, "regulator request failed (%d)\n", err);
129 /*
130 * When running on a non-dt platform and requested regulator
131 * is not available, devm_regulator_get() never returns
132 * -EPROBE_DEFER as it is not able to justify if the regulator
133 * may still appear later. On the other hand, the board can
134 * still set full constriants flag at late_initcall in order
135 * to instruct devm_regulator_get() to returnn a dummy one
136 * if sufficient. Hence, if we get -ENODEV here, let's convert
137 * it to -EPROBE_DEFER and wait for the board to decide or
138 * let Deferred Probe infrastructure handle this error.
139 */
140 if (err == -ENODEV)
141 err = -EPROBE_DEFER;
142 return err;
143 }
144
145 irq = platform_get_irq(pdev, 0);
146 if (irq < 0)
147 return -ENXIO;
148
149 err = devm_request_irq(&pdev->dev, irq, ams_delta_serio_interrupt,
150 IRQ_TYPE_EDGE_RISING, DRIVER_NAME, priv);
151 if (err < 0) {
152 dev_err(&pdev->dev, "IRQ request failed (%d)\n", err);
153 return err;
154 }
155
156 serio = kzalloc(sizeof(*serio), GFP_KERNEL);
157 if (!serio)
158 return -ENOMEM;
159
160 priv->serio = serio;
161
162 serio->id.type = SERIO_8042;
163 serio->open = ams_delta_serio_open;
164 serio->close = ams_delta_serio_close;
165 strlcpy(serio->name, "AMS DELTA keyboard adapter", sizeof(serio->name));
166 strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys));
167 serio->dev.parent = &pdev->dev;
168 serio->port_data = priv;
169
170 serio_register_port(serio);
171
172 platform_set_drvdata(pdev, priv);
173
174 dev_info(&serio->dev, "%s\n", serio->name);
175
176 return 0;
177}
178
179static int ams_delta_serio_exit(struct platform_device *pdev)
180{
181 struct ams_delta_serio *priv = platform_get_drvdata(pdev);
182
183 serio_unregister_port(priv->serio);
184
185 return 0;
186}
187
188static struct platform_driver ams_delta_serio_driver = {
189 .probe = ams_delta_serio_init,
190 .remove = ams_delta_serio_exit,
191 .driver = {
192 .name = DRIVER_NAME
193 },
194};
195module_platform_driver(ams_delta_serio_driver);
196

Warning: That file was not part of the compilation database. It may have many parsing errors.