drivers/input/touchscreen/ar1021_i2c.c

   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         { "ar1021", 0 },
 156         { },
 157 };
 158 MODULE_DEVICE_TABLE(i2c, ar1021_i2c_id);
 159
 160 static const 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                 .pm     = &ar1021_i2c_pm,
 170                 .of_match_table = ar1021_i2c_of_match,
 171         },
 172
 173         .probe          = ar1021_i2c_probe,
 174         .id_table       = ar1021_i2c_id,
 175 };
 176 module_i2c_driver(ar1021_i2c_driver);
 177
 178 MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>");
 179 MODULE_DESCRIPTION("Microchip AR1021 I2C Driver");
 180 MODULE_LICENSE("GPL");