| /* 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/slab.h> |
| #include <linux/gpio.h> |
| #include <linux/gpio_event.h> |
| #include <linux/interrupt.h> |
| |
| struct gpio_axis_state { |
| struct input_dev *input_dev; |
| 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_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_dev, ai->type, ai->code, pos); |
| } |
| input_sync(as->input_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 input_dev *input_dev, |
| 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_dev = input_dev; |
| as->info = ai; |
| |
| input_set_capability(input_dev, ai->type, ai->code); |
| if (ai->type == EV_ABS) { |
| input_set_abs_params(input_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: |
| ; |
| } |
| kfree(as); |
| *data = NULL; |
| err_alloc_axis_state_failed: |
| return ret; |
| } |