blob: d4d08bd9205b87b7ddc617c55fee84ec6259a2b8 [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>
30#include <plat/board-ams-delta.h>
31
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 */
95 ams_delta_latch2_write(AMD_DELTA_LATCH2_KEYBRD_PWR,
96 AMD_DELTA_LATCH2_KEYBRD_PWR);
97
98 return 0;
99}
100
101static void ams_delta_serio_close(struct serio *serio)
102{
103 /* disable keyboard */
104 ams_delta_latch2_write(AMD_DELTA_LATCH2_KEYBRD_PWR, 0);
105}
106
107static int __init ams_delta_serio_init(void)
108{
109 int err;
110
111 if (!machine_is_ams_delta())
112 return -ENODEV;
113
114 ams_delta_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
115 if (!ams_delta_serio)
116 return -ENOMEM;
117
118 ams_delta_serio->id.type = SERIO_8042;
119 ams_delta_serio->open = ams_delta_serio_open;
120 ams_delta_serio->close = ams_delta_serio_close;
121 strlcpy(ams_delta_serio->name, "AMS DELTA keyboard adapter",
122 sizeof(ams_delta_serio->name));
123 strlcpy(ams_delta_serio->phys, "GPIO/serio0",
124 sizeof(ams_delta_serio->phys));
125
126 err = gpio_request(AMS_DELTA_GPIO_PIN_KEYBRD_DATA, "serio-data");
127 if (err) {
128 pr_err("ams_delta_serio: Couldn't request gpio pin for data\n");
129 goto serio;
130 }
131 gpio_direction_input(AMS_DELTA_GPIO_PIN_KEYBRD_DATA);
132
133 err = gpio_request(AMS_DELTA_GPIO_PIN_KEYBRD_CLK, "serio-clock");
134 if (err) {
135 pr_err("ams_delta_serio: couldn't request gpio pin for clock\n");
136 goto gpio_data;
137 }
138 gpio_direction_input(AMS_DELTA_GPIO_PIN_KEYBRD_CLK);
139
140 err = request_irq(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK),
141 ams_delta_serio_interrupt, IRQ_TYPE_EDGE_RISING,
142 "ams-delta-serio", 0);
143 if (err < 0) {
144 pr_err("ams_delta_serio: couldn't request gpio interrupt %d\n",
145 gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK));
146 goto gpio_clk;
147 }
148 /*
149 * Since GPIO register handling for keyboard clock pin is performed
150 * at FIQ level, switch back from edge to simple interrupt handler
151 * to avoid bad interaction.
152 */
Thomas Gleixnerdced35a2011-03-28 17:49:12 +0200153 irq_set_handler(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK),
Janusz Krzysztofik29453932010-04-28 01:10:50 +0000154 handle_simple_irq);
155
156 serio_register_port(ams_delta_serio);
157 dev_info(&ams_delta_serio->dev, "%s\n", ams_delta_serio->name);
158
159 return 0;
160gpio_clk:
161 gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_CLK);
162gpio_data:
163 gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_DATA);
164serio:
165 kfree(ams_delta_serio);
166 return err;
167}
168module_init(ams_delta_serio_init);
169
170static void __exit ams_delta_serio_exit(void)
171{
172 serio_unregister_port(ams_delta_serio);
173 free_irq(OMAP_GPIO_IRQ(AMS_DELTA_GPIO_PIN_KEYBRD_CLK), 0);
174 gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_CLK);
175 gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_DATA);
Janusz Krzysztofik29453932010-04-28 01:10:50 +0000176}
177module_exit(ams_delta_serio_exit);