diff options
Diffstat (limited to 'kernel/drivers/input/serio/ams_delta_serio.c')
| -rw-r--r-- | kernel/drivers/input/serio/ams_delta_serio.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/kernel/drivers/input/serio/ams_delta_serio.c b/kernel/drivers/input/serio/ams_delta_serio.c new file mode 100644 index 000000000..45887e312 --- /dev/null +++ b/kernel/drivers/input/serio/ams_delta_serio.c @@ -0,0 +1,191 @@ +/* + * 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 <mach/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 */ + gpio_set_value(AMS_DELTA_GPIO_PIN_KEYBRD_PWR, 1); + + return 0; +} + +static void ams_delta_serio_close(struct serio *serio) +{ + /* disable keyboard */ + gpio_set_value(AMS_DELTA_GPIO_PIN_KEYBRD_PWR, 0); +} + +static const struct gpio ams_delta_gpios[] __initconst_or_module = { + { + .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_DATA, + .flags = GPIOF_DIR_IN, + .label = "serio-data", + }, + { + .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_CLK, + .flags = GPIOF_DIR_IN, + .label = "serio-clock", + }, + { + .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_PWR, + .flags = GPIOF_OUT_INIT_LOW, + .label = "serio-power", + }, + { + .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_DATAOUT, + .flags = GPIOF_OUT_INIT_LOW, + .label = "serio-dataout", + }, +}; + +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_array(ams_delta_gpios, + ARRAY_SIZE(ams_delta_gpios)); + if (err) { + pr_err("ams_delta_serio: Couldn't request gpio pins\n"); + goto serio; + } + + 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; + } + /* + * 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: + gpio_free_array(ams_delta_gpios, + ARRAY_SIZE(ams_delta_gpios)); +serio: + kfree(ams_delta_serio); + return err; +} +module_init(ams_delta_serio_init); + +static void __exit ams_delta_serio_exit(void) +{ + serio_unregister_port(ams_delta_serio); + free_irq(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK), 0); + gpio_free_array(ams_delta_gpios, + ARRAY_SIZE(ams_delta_gpios)); +} +module_exit(ams_delta_serio_exit); |