| /* |
| * Microchip AR1021 driver for I2C |
| * |
| * Author: Christian Gmeiner <christian.gmeiner@gmail.com> |
| * |
| * License: GPLv2 as published by the FSF. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/input.h> |
| #include <linux/of.h> |
| #include <linux/i2c.h> |
| #include <linux/irq.h> |
| #include <linux/interrupt.h> |
| |
| #define AR1021_TOCUH_PKG_SIZE 5 |
| |
| #define AR1021_MAX_X 4095 |
| #define AR1021_MAX_Y 4095 |
| |
| struct ar1021_i2c { |
| struct i2c_client *client; |
| struct input_dev *input; |
| u8 data[AR1021_TOCUH_PKG_SIZE]; |
| }; |
| |
| static irqreturn_t ar1021_i2c_irq(int irq, void *dev_id) |
| { |
| struct ar1021_i2c *ar1021 = dev_id; |
| struct input_dev *input = ar1021->input; |
| u8 *data = ar1021->data; |
| unsigned int x, y, button; |
| int retval; |
| |
| retval = i2c_master_recv(ar1021->client, |
| ar1021->data, sizeof(ar1021->data)); |
| if (retval != sizeof(ar1021->data)) |
| goto out; |
| |
| /* sync bit set ? */ |
| if ((data[0] & 0x80) == 0) |
| goto out; |
| |
| button = data[0] & BIT(0); |
| x = ((data[2] & 0x1f) << 7) | (data[1] & 0x7f); |
| y = ((data[4] & 0x1f) << 7) | (data[3] & 0x7f); |
| |
| input_report_abs(input, ABS_X, x); |
| input_report_abs(input, ABS_Y, y); |
| input_report_key(input, BTN_TOUCH, button); |
| input_sync(input); |
| |
| out: |
| return IRQ_HANDLED; |
| } |
| |
| static int ar1021_i2c_open(struct input_dev *dev) |
| { |
| struct ar1021_i2c *ar1021 = input_get_drvdata(dev); |
| struct i2c_client *client = ar1021->client; |
| |
| enable_irq(client->irq); |
| |
| return 0; |
| } |
| |
| static void ar1021_i2c_close(struct input_dev *dev) |
| { |
| struct ar1021_i2c *ar1021 = input_get_drvdata(dev); |
| struct i2c_client *client = ar1021->client; |
| |
| disable_irq(client->irq); |
| } |
| |
| static int ar1021_i2c_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| struct ar1021_i2c *ar1021; |
| struct input_dev *input; |
| int error; |
| |
| if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { |
| dev_err(&client->dev, "i2c_check_functionality error\n"); |
| return -ENXIO; |
| } |
| |
| ar1021 = devm_kzalloc(&client->dev, sizeof(*ar1021), GFP_KERNEL); |
| if (!ar1021) |
| return -ENOMEM; |
| |
| input = devm_input_allocate_device(&client->dev); |
| if (!input) |
| return -ENOMEM; |
| |
| ar1021->client = client; |
| ar1021->input = input; |
| |
| input->name = "ar1021 I2C Touchscreen"; |
| input->id.bustype = BUS_I2C; |
| input->dev.parent = &client->dev; |
| input->open = ar1021_i2c_open; |
| input->close = ar1021_i2c_close; |
| |
| input_set_capability(input, EV_KEY, BTN_TOUCH); |
| input_set_abs_params(input, ABS_X, 0, AR1021_MAX_X, 0, 0); |
| input_set_abs_params(input, ABS_Y, 0, AR1021_MAX_Y, 0, 0); |
| |
| input_set_drvdata(input, ar1021); |
| |
| error = devm_request_threaded_irq(&client->dev, client->irq, |
| NULL, ar1021_i2c_irq, |
| IRQF_TRIGGER_RISING | IRQF_ONESHOT, |
| "ar1021_i2c", ar1021); |
| if (error) { |
| dev_err(&client->dev, |
| "Failed to enable IRQ, error: %d\n", error); |
| return error; |
| } |
| |
| /* Disable the IRQ, we'll enable it in ar1021_i2c_open() */ |
| disable_irq(client->irq); |
| |
| error = input_register_device(ar1021->input); |
| if (error) { |
| dev_err(&client->dev, |
| "Failed to register input device, error: %d\n", error); |
| return error; |
| } |
| |
| return 0; |
| } |
| |
| static int __maybe_unused ar1021_i2c_suspend(struct device *dev) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| |
| disable_irq(client->irq); |
| |
| return 0; |
| } |
| |
| static int __maybe_unused ar1021_i2c_resume(struct device *dev) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| |
| enable_irq(client->irq); |
| |
| return 0; |
| } |
| |
| static SIMPLE_DEV_PM_OPS(ar1021_i2c_pm, ar1021_i2c_suspend, ar1021_i2c_resume); |
| |
| static const struct i2c_device_id ar1021_i2c_id[] = { |
| { "MICROCHIP_AR1021_I2C", 0 }, |
| { }, |
| }; |
| MODULE_DEVICE_TABLE(i2c, ar1021_i2c_id); |
| |
| static const struct of_device_id ar1021_i2c_of_match[] = { |
| { .compatible = "microchip,ar1021-i2c", }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, ar1021_i2c_of_match); |
| |
| static struct i2c_driver ar1021_i2c_driver = { |
| .driver = { |
| .name = "ar1021_i2c", |
| .pm = &ar1021_i2c_pm, |
| .of_match_table = ar1021_i2c_of_match, |
| }, |
| |
| .probe = ar1021_i2c_probe, |
| .id_table = ar1021_i2c_id, |
| }; |
| module_i2c_driver(ar1021_i2c_driver); |
| |
| MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>"); |
| MODULE_DESCRIPTION("Microchip AR1021 I2C Driver"); |
| MODULE_LICENSE("GPL"); |