[mirror_ubuntu-artful-kernel.git] / drivers / input / serio / ams_delta_serio.c

/*
 *  Amstrad E3 (Delta) keyboard port driver
 *
 *  Copyright (c) 2006 Matt Callow
 *  Copyright (c) 2010 Janusz Krzysztofik
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * Thanks to Cliff Lawson for his help
 *
 * The Amstrad Delta keyboard (aka mailboard) uses normal PC-AT style serial
 * transmission.  The keyboard port is formed of two GPIO lines, for clock
 * and data.  Due to strict timing requirements of the interface,
 * the serial data stream is read and processed by a FIQ handler.
 * The resulting words are fetched by this driver from a circular buffer.
 *
 * Standard AT keyboard driver (atkbd) is used for handling the keyboard data.
 * However, when used with the E3 mailboard that producecs non-standard
 * scancodes, a custom key table must be prepared and loaded from userspace.
 */
#include <linux/gpio.h>
#include <linux/irq.h>
#include <linux/serio.h>
#include <linux/slab.h>
#include <linux/module.h>

#include <asm/mach-types.h>
#include <plat/board-ams-delta.h>

#include <mach/ams-delta-fiq.h>

MODULE_AUTHOR("Matt Callow");
MODULE_DESCRIPTION("AMS Delta (E3) keyboard port driver");
MODULE_LICENSE("GPL");

static struct serio *ams_delta_serio;

static int check_data(int data)
{
	int i, parity = 0;

	/* check valid stop bit */
	if (!(data & 0x400)) {
		dev_warn(&ams_delta_serio->dev,
				"invalid stop bit, data=0x%X\n",
				data);
		return SERIO_FRAME;
	}
	/* calculate the parity */
	for (i = 1; i < 10; i++) {
		if (data & (1 << i))
			parity++;
	}
	/* it should be odd */
	if (!(parity & 0x01)) {
		dev_warn(&ams_delta_serio->dev,
				"paritiy check failed, data=0x%X parity=0x%X\n",
				data, parity);
		return SERIO_PARITY;
	}
	return 0;
}

static irqreturn_t ams_delta_serio_interrupt(int irq, void *dev_id)
{
	int *circ_buff = &fiq_buffer[FIQ_CIRC_BUFF];
	int data, dfl;
	u8 scancode;

	fiq_buffer[FIQ_IRQ_PEND] = 0;

	/*
	 * Read data from the circular buffer, check it
	 * and then pass it on the serio
	 */
	while (fiq_buffer[FIQ_KEYS_CNT] > 0) {

		data = circ_buff[fiq_buffer[FIQ_HEAD_OFFSET]++];
		fiq_buffer[FIQ_KEYS_CNT]--;
		if (fiq_buffer[FIQ_HEAD_OFFSET] == fiq_buffer[FIQ_BUF_LEN])
			fiq_buffer[FIQ_HEAD_OFFSET] = 0;

		dfl = check_data(data);
		scancode = (u8) (data >> 1) & 0xFF;
		serio_interrupt(ams_delta_serio, scancode, dfl);
	}
	return IRQ_HANDLED;
}

static int ams_delta_serio_open(struct serio *serio)
{
	/* enable keyboard */
	ams_delta_latch2_write(AMD_DELTA_LATCH2_KEYBRD_PWR,
			AMD_DELTA_LATCH2_KEYBRD_PWR);

	return 0;
}

static void ams_delta_serio_close(struct serio *serio)
{
	/* disable keyboard */
	ams_delta_latch2_write(AMD_DELTA_LATCH2_KEYBRD_PWR, 0);
}

static int __init ams_delta_serio_init(void)
{
	int err;

	if (!machine_is_ams_delta())
		return -ENODEV;

	ams_delta_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
	if (!ams_delta_serio)
		return -ENOMEM;

	ams_delta_serio->id.type = SERIO_8042;
	ams_delta_serio->open = ams_delta_serio_open;
	ams_delta_serio->close = ams_delta_serio_close;
	strlcpy(ams_delta_serio->name, "AMS DELTA keyboard adapter",
			sizeof(ams_delta_serio->name));
	strlcpy(ams_delta_serio->phys, "GPIO/serio0",
			sizeof(ams_delta_serio->phys));

	err = gpio_request(AMS_DELTA_GPIO_PIN_KEYBRD_DATA, "serio-data");
	if (err) {
		pr_err("ams_delta_serio: Couldn't request gpio pin for data\n");
		goto serio;
	}
	gpio_direction_input(AMS_DELTA_GPIO_PIN_KEYBRD_DATA);

	err = gpio_request(AMS_DELTA_GPIO_PIN_KEYBRD_CLK, "serio-clock");
	if (err) {
		pr_err("ams_delta_serio: couldn't request gpio pin for clock\n");
		goto gpio_data;
	}
	gpio_direction_input(AMS_DELTA_GPIO_PIN_KEYBRD_CLK);

	err = request_irq(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK),
			ams_delta_serio_interrupt, IRQ_TYPE_EDGE_RISING,
			"ams-delta-serio", 0);
	if (err < 0) {
		pr_err("ams_delta_serio: couldn't request gpio interrupt %d\n",
				gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK));
		goto gpio_clk;
	}
	/*
	 * Since GPIO register handling for keyboard clock pin is performed
	 * at FIQ level, switch back from edge to simple interrupt handler
	 * to avoid bad interaction.
	 */
	irq_set_handler(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK),
			handle_simple_irq);

	serio_register_port(ams_delta_serio);
	dev_info(&ams_delta_serio->dev, "%s\n", ams_delta_serio->name);

	return 0;
gpio_clk:
	gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_CLK);
gpio_data:
	gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_DATA);
serio:
	kfree(ams_delta_serio);
	return err;
}
late_initcall(ams_delta_serio_init);

static void __exit ams_delta_serio_exit(void)
{
	serio_unregister_port(ams_delta_serio);
	free_irq(OMAP_GPIO_IRQ(AMS_DELTA_GPIO_PIN_KEYBRD_CLK), 0);
	gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_CLK);
	gpio_free(AMS_DELTA_GPIO_PIN_KEYBRD_DATA);
}
module_exit(ams_delta_serio_exit);
Commit	Line	Data
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>
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	}
f7519d8c	168	late_initcall(ams_delta_serio_init);
29453932 JK	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	}
29453932 JK	177	module_exit(ams_delta_serio_exit);