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| 1 | +/* |
| 2 | + * Microchip AR1021 driver for I2C |
| 3 | + * |
| 4 | + * Author: Christian Gmeiner <christian.gmeiner@gmail.com> |
| 5 | + * |
| 6 | + * License: GPLv2 as published by the FSF. |
| 7 | + */ |
| 8 | + |
| 9 | +#include <linux/module.h> |
| 10 | +#include <linux/input.h> |
| 11 | +#include <linux/of.h> |
| 12 | +#include <linux/i2c.h> |
| 13 | +#include <linux/irq.h> |
| 14 | +#include <linux/interrupt.h> |
| 15 | + |
| 16 | +#define AR1021_TOCUH_PKG_SIZE 5 |
| 17 | + |
| 18 | +#define AR1021_MAX_X 4095 |
| 19 | +#define AR1021_MAX_Y 4095 |
| 20 | + |
| 21 | +struct ar1021_i2c { |
| 22 | + struct i2c_client *client; |
| 23 | + struct input_dev *input; |
| 24 | + u8 data[AR1021_TOCUH_PKG_SIZE]; |
| 25 | +}; |
| 26 | + |
| 27 | +static irqreturn_t ar1021_i2c_irq(int irq, void *dev_id) |
| 28 | +{ |
| 29 | + struct ar1021_i2c *ar1021 = dev_id; |
| 30 | + struct input_dev *input = ar1021->input; |
| 31 | + u8 *data = ar1021->data; |
| 32 | + unsigned int x, y, button; |
| 33 | + int retval; |
| 34 | + |
| 35 | + retval = i2c_master_recv(ar1021->client, |
| 36 | + ar1021->data, sizeof(ar1021->data)); |
| 37 | + if (retval != sizeof(ar1021->data)) |
| 38 | + goto out; |
| 39 | + |
| 40 | + /* sync bit set ? */ |
| 41 | + if ((data[0] & 0x80) == 0) |
| 42 | + goto out; |
| 43 | + |
| 44 | + button = data[0] & BIT(0); |
| 45 | + x = ((data[2] & 0x1f) << 7) | (data[1] & 0x7f); |
| 46 | + y = ((data[4] & 0x1f) << 7) | (data[3] & 0x7f); |
| 47 | + |
| 48 | + input_report_abs(input, ABS_X, x); |
| 49 | + input_report_abs(input, ABS_Y, y); |
| 50 | + input_report_key(input, BTN_TOUCH, button); |
| 51 | + input_sync(input); |
| 52 | + |
| 53 | +out: |
| 54 | + return IRQ_HANDLED; |
| 55 | +} |
| 56 | + |
| 57 | +static int ar1021_i2c_open(struct input_dev *dev) |
| 58 | +{ |
| 59 | + struct ar1021_i2c *ar1021 = input_get_drvdata(dev); |
| 60 | + struct i2c_client *client = ar1021->client; |
| 61 | + |
| 62 | + enable_irq(client->irq); |
| 63 | + |
| 64 | + return 0; |
| 65 | +} |
| 66 | + |
| 67 | +static void ar1021_i2c_close(struct input_dev *dev) |
| 68 | +{ |
| 69 | + struct ar1021_i2c *ar1021 = input_get_drvdata(dev); |
| 70 | + struct i2c_client *client = ar1021->client; |
| 71 | + |
| 72 | + disable_irq(client->irq); |
| 73 | +} |
| 74 | + |
| 75 | +static int ar1021_i2c_probe(struct i2c_client *client, |
| 76 | + const struct i2c_device_id *id) |
| 77 | +{ |
| 78 | + struct ar1021_i2c *ar1021; |
| 79 | + struct input_dev *input; |
| 80 | + int error; |
| 81 | + |
| 82 | + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { |
| 83 | + dev_err(&client->dev, "i2c_check_functionality error\n"); |
| 84 | + return -ENXIO; |
| 85 | + } |
| 86 | + |
| 87 | + ar1021 = devm_kzalloc(&client->dev, sizeof(*ar1021), GFP_KERNEL); |
| 88 | + if (!ar1021) |
| 89 | + return -ENOMEM; |
| 90 | + |
| 91 | + input = devm_input_allocate_device(&client->dev); |
| 92 | + if (!input) |
| 93 | + return -ENOMEM; |
| 94 | + |
| 95 | + ar1021->client = client; |
| 96 | + ar1021->input = input; |
| 97 | + |
| 98 | + input->name = "ar1021 I2C Touchscreen"; |
| 99 | + input->id.bustype = BUS_I2C; |
| 100 | + input->dev.parent = &client->dev; |
| 101 | + input->open = ar1021_i2c_open; |
| 102 | + input->close = ar1021_i2c_close; |
| 103 | + |
| 104 | + input_set_capability(input, EV_KEY, BTN_TOUCH); |
| 105 | + input_set_abs_params(input, ABS_X, 0, AR1021_MAX_X, 0, 0); |
| 106 | + input_set_abs_params(input, ABS_Y, 0, AR1021_MAX_Y, 0, 0); |
| 107 | + |
| 108 | + input_set_drvdata(input, ar1021); |
| 109 | + |
| 110 | + error = devm_request_threaded_irq(&client->dev, client->irq, |
| 111 | + NULL, ar1021_i2c_irq, |
| 112 | + IRQF_TRIGGER_RISING | IRQF_ONESHOT, |
| 113 | + "ar1021_i2c", ar1021); |
| 114 | + if (error) { |
| 115 | + dev_err(&client->dev, |
| 116 | + "Failed to enable IRQ, error: %d\n", error); |
| 117 | + return error; |
| 118 | + } |
| 119 | + |
| 120 | + /* Disable the IRQ, we'll enable it in ar1021_i2c_open() */ |
| 121 | + disable_irq(client->irq); |
| 122 | + |
| 123 | + error = input_register_device(ar1021->input); |
| 124 | + if (error) { |
| 125 | + dev_err(&client->dev, |
| 126 | + "Failed to register input device, error: %d\n", error); |
| 127 | + return error; |
| 128 | + } |
| 129 | + |
| 130 | + i2c_set_clientdata(client, ar1021); |
| 131 | + return 0; |
| 132 | +} |
| 133 | + |
| 134 | +static int __maybe_unused ar1021_i2c_suspend(struct device *dev) |
| 135 | +{ |
| 136 | + struct i2c_client *client = to_i2c_client(dev); |
| 137 | + |
| 138 | + disable_irq(client->irq); |
| 139 | + |
| 140 | + return 0; |
| 141 | +} |
| 142 | + |
| 143 | +static int __maybe_unused ar1021_i2c_resume(struct device *dev) |
| 144 | +{ |
| 145 | + struct i2c_client *client = to_i2c_client(dev); |
| 146 | + |
| 147 | + enable_irq(client->irq); |
| 148 | + |
| 149 | + return 0; |
| 150 | +} |
| 151 | + |
| 152 | +static SIMPLE_DEV_PM_OPS(ar1021_i2c_pm, ar1021_i2c_suspend, ar1021_i2c_resume); |
| 153 | + |
| 154 | +static const struct i2c_device_id ar1021_i2c_id[] = { |
| 155 | + { "MICROCHIP_AR1021_I2C", 0 }, |
| 156 | + { }, |
| 157 | +}; |
| 158 | +MODULE_DEVICE_TABLE(i2c, ar1021_i2c_id); |
| 159 | + |
| 160 | +static struct of_device_id ar1021_i2c_of_match[] = { |
| 161 | + { .compatible = "microchip,ar1021-i2c", }, |
| 162 | + { } |
| 163 | +}; |
| 164 | +MODULE_DEVICE_TABLE(of, ar1021_i2c_of_match); |
| 165 | + |
| 166 | +static struct i2c_driver ar1021_i2c_driver = { |
| 167 | + .driver = { |
| 168 | + .name = "ar1021_i2c", |
| 169 | + .owner = THIS_MODULE, |
| 170 | + .pm = &ar1021_i2c_pm, |
| 171 | + .of_match_table = ar1021_i2c_of_match, |
| 172 | + }, |
| 173 | + |
| 174 | + .probe = ar1021_i2c_probe, |
| 175 | + .id_table = ar1021_i2c_id, |
| 176 | +}; |
| 177 | +module_i2c_driver(ar1021_i2c_driver); |
| 178 | + |
| 179 | +MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>"); |
| 180 | +MODULE_DESCRIPTION("Microchip AR1021 I2C Driver"); |
| 181 | +MODULE_LICENSE("GPL"); |
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