diff options
Diffstat (limited to 'drivers/input/misc/gpio_axis.c')
| -rw-r--r-- | drivers/input/misc/gpio_axis.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/input/misc/gpio_axis.c b/drivers/input/misc/gpio_axis.c new file mode 100644 index 000000000000..0acf4a576f53 --- /dev/null +++ b/drivers/input/misc/gpio_axis.c @@ -0,0 +1,192 @@ +/* drivers/input/misc/gpio_axis.c + * + * Copyright (C) 2007 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/kernel.h> +#include <linux/gpio.h> +#include <linux/gpio_event.h> +#include <linux/interrupt.h> +#include <linux/slab.h> + +struct gpio_axis_state { + struct gpio_event_input_devs *input_devs; + struct gpio_event_axis_info *info; + uint32_t pos; +}; + +uint16_t gpio_axis_4bit_gray_map_table[] = { + [0x0] = 0x0, [0x1] = 0x1, /* 0000 0001 */ + [0x3] = 0x2, [0x2] = 0x3, /* 0011 0010 */ + [0x6] = 0x4, [0x7] = 0x5, /* 0110 0111 */ + [0x5] = 0x6, [0x4] = 0x7, /* 0101 0100 */ + [0xc] = 0x8, [0xd] = 0x9, /* 1100 1101 */ + [0xf] = 0xa, [0xe] = 0xb, /* 1111 1110 */ + [0xa] = 0xc, [0xb] = 0xd, /* 1010 1011 */ + [0x9] = 0xe, [0x8] = 0xf, /* 1001 1000 */ +}; +uint16_t gpio_axis_4bit_gray_map(struct gpio_event_axis_info *info, uint16_t in) +{ + return gpio_axis_4bit_gray_map_table[in]; +} + +uint16_t gpio_axis_5bit_singletrack_map_table[] = { + [0x10] = 0x00, [0x14] = 0x01, [0x1c] = 0x02, /* 10000 10100 11100 */ + [0x1e] = 0x03, [0x1a] = 0x04, [0x18] = 0x05, /* 11110 11010 11000 */ + [0x08] = 0x06, [0x0a] = 0x07, [0x0e] = 0x08, /* 01000 01010 01110 */ + [0x0f] = 0x09, [0x0d] = 0x0a, [0x0c] = 0x0b, /* 01111 01101 01100 */ + [0x04] = 0x0c, [0x05] = 0x0d, [0x07] = 0x0e, /* 00100 00101 00111 */ + [0x17] = 0x0f, [0x16] = 0x10, [0x06] = 0x11, /* 10111 10110 00110 */ + [0x02] = 0x12, [0x12] = 0x13, [0x13] = 0x14, /* 00010 10010 10011 */ + [0x1b] = 0x15, [0x0b] = 0x16, [0x03] = 0x17, /* 11011 01011 00011 */ + [0x01] = 0x18, [0x09] = 0x19, [0x19] = 0x1a, /* 00001 01001 11001 */ + [0x1d] = 0x1b, [0x15] = 0x1c, [0x11] = 0x1d, /* 11101 10101 10001 */ +}; +uint16_t gpio_axis_5bit_singletrack_map( + struct gpio_event_axis_info *info, uint16_t in) +{ + return gpio_axis_5bit_singletrack_map_table[in]; +} + +static void gpio_event_update_axis(struct gpio_axis_state *as, int report) +{ + struct gpio_event_axis_info *ai = as->info; + int i; + int change; + uint16_t state = 0; + uint16_t pos; + uint16_t old_pos = as->pos; + for (i = ai->count - 1; i >= 0; i--) + state = (state << 1) | gpio_get_value(ai->gpio[i]); + pos = ai->map(ai, state); + if (ai->flags & GPIOEAF_PRINT_RAW) + pr_info("axis %d-%d raw %x, pos %d -> %d\n", + ai->type, ai->code, state, old_pos, pos); + if (report && pos != old_pos) { + if (ai->type == EV_REL) { + change = (ai->decoded_size + pos - old_pos) % + ai->decoded_size; + if (change > ai->decoded_size / 2) + change -= ai->decoded_size; + if (change == ai->decoded_size / 2) { + if (ai->flags & GPIOEAF_PRINT_EVENT) + pr_info("axis %d-%d unknown direction, " + "pos %d -> %d\n", ai->type, + ai->code, old_pos, pos); + change = 0; /* no closest direction */ + } + if (ai->flags & GPIOEAF_PRINT_EVENT) + pr_info("axis %d-%d change %d\n", + ai->type, ai->code, change); + input_report_rel(as->input_devs->dev[ai->dev], + ai->code, change); + } else { + if (ai->flags & GPIOEAF_PRINT_EVENT) + pr_info("axis %d-%d now %d\n", + ai->type, ai->code, pos); + input_event(as->input_devs->dev[ai->dev], + ai->type, ai->code, pos); + } + input_sync(as->input_devs->dev[ai->dev]); + } + as->pos = pos; +} + +static irqreturn_t gpio_axis_irq_handler(int irq, void *dev_id) +{ + struct gpio_axis_state *as = dev_id; + gpio_event_update_axis(as, 1); + return IRQ_HANDLED; +} + +int gpio_event_axis_func(struct gpio_event_input_devs *input_devs, + struct gpio_event_info *info, void **data, int func) +{ + int ret; + int i; + int irq; + struct gpio_event_axis_info *ai; + struct gpio_axis_state *as; + + ai = container_of(info, struct gpio_event_axis_info, info); + if (func == GPIO_EVENT_FUNC_SUSPEND) { + for (i = 0; i < ai->count; i++) + disable_irq(gpio_to_irq(ai->gpio[i])); + return 0; + } + if (func == GPIO_EVENT_FUNC_RESUME) { + for (i = 0; i < ai->count; i++) + enable_irq(gpio_to_irq(ai->gpio[i])); + return 0; + } + + if (func == GPIO_EVENT_FUNC_INIT) { + *data = as = kmalloc(sizeof(*as), GFP_KERNEL); + if (as == NULL) { + ret = -ENOMEM; + goto err_alloc_axis_state_failed; + } + as->input_devs = input_devs; + as->info = ai; + if (ai->dev >= input_devs->count) { + pr_err("gpio_event_axis: bad device index %d >= %d " + "for %d:%d\n", ai->dev, input_devs->count, + ai->type, ai->code); + ret = -EINVAL; + goto err_bad_device_index; + } + + input_set_capability(input_devs->dev[ai->dev], + ai->type, ai->code); + if (ai->type == EV_ABS) { + input_set_abs_params(input_devs->dev[ai->dev], ai->code, + 0, ai->decoded_size - 1, 0, 0); + } + for (i = 0; i < ai->count; i++) { + ret = gpio_request(ai->gpio[i], "gpio_event_axis"); + if (ret < 0) + goto err_request_gpio_failed; + ret = gpio_direction_input(ai->gpio[i]); + if (ret < 0) + goto err_gpio_direction_input_failed; + ret = irq = gpio_to_irq(ai->gpio[i]); + if (ret < 0) + goto err_get_irq_num_failed; + ret = request_irq(irq, gpio_axis_irq_handler, + IRQF_TRIGGER_RISING | + IRQF_TRIGGER_FALLING, + "gpio_event_axis", as); + if (ret < 0) + goto err_request_irq_failed; + } + gpio_event_update_axis(as, 0); + return 0; + } + + ret = 0; + as = *data; + for (i = ai->count - 1; i >= 0; i--) { + free_irq(gpio_to_irq(ai->gpio[i]), as); +err_request_irq_failed: +err_get_irq_num_failed: +err_gpio_direction_input_failed: + gpio_free(ai->gpio[i]); +err_request_gpio_failed: + ; + } +err_bad_device_index: + kfree(as); + *data = NULL; +err_alloc_axis_state_failed: + return ret; +} |