blob: 45887e31242acf6843692764f45b77aa929ccaa2 [file] [log] [blame]
Janusz Krzysztofik29453932010-04-28 01:10:50 +00001/*
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/gpio.h>
24#include <linux/irq.h>
25#include <linux/serio.h>
26#include <linux/slab.h>
Aaro Koskinen77f6ca52011-11-09 10:13:33 -080027#include <linux/module.h>
Janusz Krzysztofik29453932010-04-28 01:10:50 +000028
29#include <asm/mach-types.h>
Tony Lindgrene27e35e2012-09-19 10:33:43 -070030#include <mach/board-ams-delta.h>
Janusz Krzysztofik29453932010-04-28 01:10:50 +000031
32#include <mach/ams-delta-fiq.h>
33
34MODULE_AUTHOR("Matt Callow");
35MODULE_DESCRIPTION("AMS Delta (E3) keyboard port driver");
36MODULE_LICENSE("GPL");
37
38static struct serio *ams_delta_serio;
39
40static int check_data(int data)
41{
42 int i, parity = 0;
43
44 /* check valid stop bit */
45 if (!(data & 0x400)) {
46 dev_warn(&ams_delta_serio->dev,
47 "invalid stop bit, data=0x%X\n",
48 data);
49 return SERIO_FRAME;
50 }
51 /* calculate the parity */
52 for (i = 1; i < 10; i++) {
53 if (data & (1 << i))
54 parity++;
55 }
56 /* it should be odd */
57 if (!(parity & 0x01)) {
58 dev_warn(&ams_delta_serio->dev,
59 "paritiy check failed, data=0x%X parity=0x%X\n",
60 data, parity);
61 return SERIO_PARITY;
62 }
63 return 0;
64}
65
66static irqreturn_t ams_delta_serio_interrupt(int irq, void *dev_id)
67{
68 int *circ_buff = &fiq_buffer[FIQ_CIRC_BUFF];
69 int data, dfl;
70 u8 scancode;
71
72 fiq_buffer[FIQ_IRQ_PEND] = 0;
73
74 /*
75 * Read data from the circular buffer, check it
76 * and then pass it on the serio
77 */
78 while (fiq_buffer[FIQ_KEYS_CNT] > 0) {
79
80 data = circ_buff[fiq_buffer[FIQ_HEAD_OFFSET]++];
81 fiq_buffer[FIQ_KEYS_CNT]--;
82 if (fiq_buffer[FIQ_HEAD_OFFSET] == fiq_buffer[FIQ_BUF_LEN])
83 fiq_buffer[FIQ_HEAD_OFFSET] = 0;
84
85 dfl = check_data(data);
86 scancode = (u8) (data >> 1) & 0xFF;
87 serio_interrupt(ams_delta_serio, scancode, dfl);
88 }
89 return IRQ_HANDLED;
90}
91
92static int ams_delta_serio_open(struct serio *serio)
93{
94 /* enable keyboard */
Janusz Krzysztofik8d09a1b2011-12-20 23:10:34 +010095 gpio_set_value(AMS_DELTA_GPIO_PIN_KEYBRD_PWR, 1);
Janusz Krzysztofik29453932010-04-28 01:10:50 +000096
97 return 0;
98}
99
100static void ams_delta_serio_close(struct serio *serio)
101{
102 /* disable keyboard */
Janusz Krzysztofik8d09a1b2011-12-20 23:10:34 +0100103 gpio_set_value(AMS_DELTA_GPIO_PIN_KEYBRD_PWR, 0);
Janusz Krzysztofik29453932010-04-28 01:10:50 +0000104}
105
Janusz Krzysztofikda564a02012-02-10 17:48:43 +0100106static const struct gpio ams_delta_gpios[] __initconst_or_module = {
Janusz Krzysztofik8d09a1b2011-12-20 23:10:34 +0100107 {
108 .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_DATA,
109 .flags = GPIOF_DIR_IN,
110 .label = "serio-data",
111 },
112 {
113 .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_CLK,
114 .flags = GPIOF_DIR_IN,
115 .label = "serio-clock",
116 },
117 {
118 .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_PWR,
119 .flags = GPIOF_OUT_INIT_LOW,
120 .label = "serio-power",
121 },
122 {
123 .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_DATAOUT,
124 .flags = GPIOF_OUT_INIT_LOW,
125 .label = "serio-dataout",
126 },
127};
128
Janusz Krzysztofik29453932010-04-28 01:10:50 +0000129static int __init ams_delta_serio_init(void)
130{
131 int err;
132
133 if (!machine_is_ams_delta())
134 return -ENODEV;
135
136 ams_delta_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
137 if (!ams_delta_serio)
138 return -ENOMEM;
139
140 ams_delta_serio->id.type = SERIO_8042;
141 ams_delta_serio->open = ams_delta_serio_open;
142 ams_delta_serio->close = ams_delta_serio_close;
143 strlcpy(ams_delta_serio->name, "AMS DELTA keyboard adapter",
144 sizeof(ams_delta_serio->name));
145 strlcpy(ams_delta_serio->phys, "GPIO/serio0",
146 sizeof(ams_delta_serio->phys));
147
Janusz Krzysztofik8d09a1b2011-12-20 23:10:34 +0100148 err = gpio_request_array(ams_delta_gpios,
149 ARRAY_SIZE(ams_delta_gpios));
Janusz Krzysztofik29453932010-04-28 01:10:50 +0000150 if (err) {
Janusz Krzysztofik8d09a1b2011-12-20 23:10:34 +0100151 pr_err("ams_delta_serio: Couldn't request gpio pins\n");
Janusz Krzysztofik29453932010-04-28 01:10:50 +0000152 goto serio;
153 }
Janusz Krzysztofik29453932010-04-28 01:10:50 +0000154
155 err = request_irq(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK),
156 ams_delta_serio_interrupt, IRQ_TYPE_EDGE_RISING,
157 "ams-delta-serio", 0);
158 if (err < 0) {
159 pr_err("ams_delta_serio: couldn't request gpio interrupt %d\n",
160 gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK));
Janusz Krzysztofik8d09a1b2011-12-20 23:10:34 +0100161 goto gpio;
Janusz Krzysztofik29453932010-04-28 01:10:50 +0000162 }
163 /*
164 * Since GPIO register handling for keyboard clock pin is performed
165 * at FIQ level, switch back from edge to simple interrupt handler
166 * to avoid bad interaction.
167 */
Thomas Gleixnerdced35a2011-03-28 17:49:12 +0200168 irq_set_handler(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK),
Janusz Krzysztofik29453932010-04-28 01:10:50 +0000169 handle_simple_irq);
170
171 serio_register_port(ams_delta_serio);
172 dev_info(&ams_delta_serio->dev, "%s\n", ams_delta_serio->name);
173
174 return 0;
Janusz Krzysztofik8d09a1b2011-12-20 23:10:34 +0100175gpio:
176 gpio_free_array(ams_delta_gpios,
177 ARRAY_SIZE(ams_delta_gpios));
Janusz Krzysztofik29453932010-04-28 01:10:50 +0000178serio:
179 kfree(ams_delta_serio);
180 return err;
181}
Janusz Krzysztofik8d09a1b2011-12-20 23:10:34 +0100182module_init(ams_delta_serio_init);
Janusz Krzysztofik29453932010-04-28 01:10:50 +0000183
184static void __exit ams_delta_serio_exit(void)
185{
186 serio_unregister_port(ams_delta_serio);
Tarun Kanti DebBarmae6801af2012-03-29 08:41:01 -0700187 free_irq(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK), 0);
Janusz Krzysztofik8d09a1b2011-12-20 23:10:34 +0100188 gpio_free_array(ams_delta_gpios,
189 ARRAY_SIZE(ams_delta_gpios));
Janusz Krzysztofik29453932010-04-28 01:10:50 +0000190}
191module_exit(ams_delta_serio_exit);