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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/gpio.h> | |
24 | #include <linux/irq.h> | |
25 | #include <linux/serio.h> | |
26 | #include <linux/slab.h> | |
77f6ca5a | 27 | #include <linux/module.h> |
29453932 JK |
28 | |
29 | #include <asm/mach-types.h> | |
30 | #include <plat/board-ams-delta.h> | |
31 | ||
32 | #include <mach/ams-delta-fiq.h> | |
33 | ||
34 | MODULE_AUTHOR("Matt Callow"); | |
35 | MODULE_DESCRIPTION("AMS Delta (E3) keyboard port driver"); | |
36 | MODULE_LICENSE("GPL"); | |
37 | ||
38 | static struct serio *ams_delta_serio; | |
39 | ||
40 | static 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 | ||
66 | static 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 | ||
92 | static 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 | ||
101 | static 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 | ||
107 | static 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 | */ | |
dced35ae | 153 | irq_set_handler(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK), |
29453932 JK |
154 | 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; | |
160 | gpio_clk: | |
161 | gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_CLK); | |
162 | gpio_data: | |
163 | gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_DATA); | |
164 | serio: | |
165 | kfree(ams_delta_serio); | |
166 | return err; | |
167 | } | |
168 | module_init(ams_delta_serio_init); | |
169 | ||
170 | static 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); | |
29453932 JK |
176 | } |
177 | module_exit(ams_delta_serio_exit); |