Commit | Line | Data |
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29453932 JK |
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/gpio.h> | |
24 | #include <linux/irq.h> | |
25 | #include <linux/serio.h> | |
26 | #include <linux/slab.h> | |
27 | ||
28 | #include <asm/mach-types.h> | |
29 | #include <plat/board-ams-delta.h> | |
30 | ||
31 | #include <mach/ams-delta-fiq.h> | |
32 | ||
33 | MODULE_AUTHOR("Matt Callow"); | |
34 | MODULE_DESCRIPTION("AMS Delta (E3) keyboard port driver"); | |
35 | MODULE_LICENSE("GPL"); | |
36 | ||
37 | static struct serio *ams_delta_serio; | |
38 | ||
39 | static int check_data(int data) | |
40 | { | |
41 | int i, parity = 0; | |
42 | ||
43 | /* check valid stop bit */ | |
44 | if (!(data & 0x400)) { | |
45 | dev_warn(&ams_delta_serio->dev, | |
46 | "invalid stop bit, data=0x%X\n", | |
47 | data); | |
48 | return SERIO_FRAME; | |
49 | } | |
50 | /* calculate the parity */ | |
51 | for (i = 1; i < 10; i++) { | |
52 | if (data & (1 << i)) | |
53 | parity++; | |
54 | } | |
55 | /* it should be odd */ | |
56 | if (!(parity & 0x01)) { | |
57 | dev_warn(&ams_delta_serio->dev, | |
58 | "paritiy check failed, data=0x%X parity=0x%X\n", | |
59 | data, parity); | |
60 | return SERIO_PARITY; | |
61 | } | |
62 | return 0; | |
63 | } | |
64 | ||
65 | static irqreturn_t ams_delta_serio_interrupt(int irq, void *dev_id) | |
66 | { | |
67 | int *circ_buff = &fiq_buffer[FIQ_CIRC_BUFF]; | |
68 | int data, dfl; | |
69 | u8 scancode; | |
70 | ||
71 | fiq_buffer[FIQ_IRQ_PEND] = 0; | |
72 | ||
73 | /* | |
74 | * Read data from the circular buffer, check it | |
75 | * and then pass it on the serio | |
76 | */ | |
77 | while (fiq_buffer[FIQ_KEYS_CNT] > 0) { | |
78 | ||
79 | data = circ_buff[fiq_buffer[FIQ_HEAD_OFFSET]++]; | |
80 | fiq_buffer[FIQ_KEYS_CNT]--; | |
81 | if (fiq_buffer[FIQ_HEAD_OFFSET] == fiq_buffer[FIQ_BUF_LEN]) | |
82 | fiq_buffer[FIQ_HEAD_OFFSET] = 0; | |
83 | ||
84 | dfl = check_data(data); | |
85 | scancode = (u8) (data >> 1) & 0xFF; | |
86 | serio_interrupt(ams_delta_serio, scancode, dfl); | |
87 | } | |
88 | return IRQ_HANDLED; | |
89 | } | |
90 | ||
91 | static int ams_delta_serio_open(struct serio *serio) | |
92 | { | |
93 | /* enable keyboard */ | |
94 | ams_delta_latch2_write(AMD_DELTA_LATCH2_KEYBRD_PWR, | |
95 | AMD_DELTA_LATCH2_KEYBRD_PWR); | |
96 | ||
97 | return 0; | |
98 | } | |
99 | ||
100 | static void ams_delta_serio_close(struct serio *serio) | |
101 | { | |
102 | /* disable keyboard */ | |
103 | ams_delta_latch2_write(AMD_DELTA_LATCH2_KEYBRD_PWR, 0); | |
104 | } | |
105 | ||
106 | static int __init ams_delta_serio_init(void) | |
107 | { | |
108 | int err; | |
109 | ||
110 | if (!machine_is_ams_delta()) | |
111 | return -ENODEV; | |
112 | ||
113 | ams_delta_serio = kzalloc(sizeof(struct serio), GFP_KERNEL); | |
114 | if (!ams_delta_serio) | |
115 | return -ENOMEM; | |
116 | ||
117 | ams_delta_serio->id.type = SERIO_8042; | |
118 | ams_delta_serio->open = ams_delta_serio_open; | |
119 | ams_delta_serio->close = ams_delta_serio_close; | |
120 | strlcpy(ams_delta_serio->name, "AMS DELTA keyboard adapter", | |
121 | sizeof(ams_delta_serio->name)); | |
122 | strlcpy(ams_delta_serio->phys, "GPIO/serio0", | |
123 | sizeof(ams_delta_serio->phys)); | |
124 | ||
125 | err = gpio_request(AMS_DELTA_GPIO_PIN_KEYBRD_DATA, "serio-data"); | |
126 | if (err) { | |
127 | pr_err("ams_delta_serio: Couldn't request gpio pin for data\n"); | |
128 | goto serio; | |
129 | } | |
130 | gpio_direction_input(AMS_DELTA_GPIO_PIN_KEYBRD_DATA); | |
131 | ||
132 | err = gpio_request(AMS_DELTA_GPIO_PIN_KEYBRD_CLK, "serio-clock"); | |
133 | if (err) { | |
134 | pr_err("ams_delta_serio: couldn't request gpio pin for clock\n"); | |
135 | goto gpio_data; | |
136 | } | |
137 | gpio_direction_input(AMS_DELTA_GPIO_PIN_KEYBRD_CLK); | |
138 | ||
139 | err = request_irq(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK), | |
140 | ams_delta_serio_interrupt, IRQ_TYPE_EDGE_RISING, | |
141 | "ams-delta-serio", 0); | |
142 | if (err < 0) { | |
143 | pr_err("ams_delta_serio: couldn't request gpio interrupt %d\n", | |
144 | gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK)); | |
145 | goto gpio_clk; | |
146 | } | |
147 | /* | |
148 | * Since GPIO register handling for keyboard clock pin is performed | |
149 | * at FIQ level, switch back from edge to simple interrupt handler | |
150 | * to avoid bad interaction. | |
151 | */ | |
152 | set_irq_handler(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK), | |
153 | handle_simple_irq); | |
154 | ||
155 | serio_register_port(ams_delta_serio); | |
156 | dev_info(&ams_delta_serio->dev, "%s\n", ams_delta_serio->name); | |
157 | ||
158 | return 0; | |
159 | gpio_clk: | |
160 | gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_CLK); | |
161 | gpio_data: | |
162 | gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_DATA); | |
163 | serio: | |
164 | kfree(ams_delta_serio); | |
165 | return err; | |
166 | } | |
167 | module_init(ams_delta_serio_init); | |
168 | ||
169 | static void __exit ams_delta_serio_exit(void) | |
170 | { | |
171 | serio_unregister_port(ams_delta_serio); | |
172 | free_irq(OMAP_GPIO_IRQ(AMS_DELTA_GPIO_PIN_KEYBRD_CLK), 0); | |
173 | gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_CLK); | |
174 | gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_DATA); | |
175 | kfree(ams_delta_serio); | |
176 | } | |
177 | module_exit(ams_delta_serio_exit); |