drivers/input/touchscreen/ar1021_i2c.c

   1 /*
   2  * Microchip AR1020 and 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/bitops.h>
  10 #include <linux/module.h>
  11 #include <linux/input.h>
  12 #include <linux/of.h>
  13 #include <linux/i2c.h>
  14 #include <linux/irq.h>
  15 #include <linux/interrupt.h>
  16
  17 #define AR1021_TOCUH_PKG_SIZE   5
  18
  19 #define AR1021_MAX_X    4095
  20 #define AR1021_MAX_Y    4095
  21
  22 #define AR1021_CMD      0x55
  23
  24 #define AR1021_CMD_ENABLE_TOUCH         0x12
  25
  26 struct ar1021_i2c {
  27         struct i2c_client *client;
  28         struct input_dev *input;
  29         u8 data[AR1021_TOCUH_PKG_SIZE];
  30 };
  31
  32 static irqreturn_t ar1021_i2c_irq(int irq, void *dev_id)
  33 {
  34         struct ar1021_i2c *ar1021 = dev_id;
  35         struct input_dev *input = ar1021->input;
  36         u8 *data = ar1021->data;
  37         unsigned int x, y, button;
  38         int retval;
  39
  40         retval = i2c_master_recv(ar1021->client,
  41                                  ar1021->data, sizeof(ar1021->data));
  42         if (retval != sizeof(ar1021->data))
  43                 goto out;
  44
  45         /* sync bit set ? */
  46         if (!(data[0] & BIT(7)))
  47                 goto out;
  48
  49         button = data[0] & BIT(0);
  50         x = ((data[2] & 0x1f) << 7) | (data[1] & 0x7f);
  51         y = ((data[4] & 0x1f) << 7) | (data[3] & 0x7f);
  52
  53         input_report_abs(input, ABS_X, x);
  54         input_report_abs(input, ABS_Y, y);
  55         input_report_key(input, BTN_TOUCH, button);
  56         input_sync(input);
  57
  58 out:
  59         return IRQ_HANDLED;
  60 }
  61
  62 static int ar1021_i2c_open(struct input_dev *dev)
  63 {
  64         static const u8 cmd_enable_touch[] = {
  65                 AR1021_CMD,
  66                 0x01, /* number of bytes after this */
  67                 AR1021_CMD_ENABLE_TOUCH
  68         };
  69         struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
  70         struct i2c_client *client = ar1021->client;
  71         int error;
  72
  73         error = i2c_master_send(ar1021->client, cmd_enable_touch,
  74                                 sizeof(cmd_enable_touch));
  75         if (error < 0)
  76                 return error;
  77
  78         enable_irq(client->irq);
  79
  80         return 0;
  81 }
  82
  83 static void ar1021_i2c_close(struct input_dev *dev)
  84 {
  85         struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
  86         struct i2c_client *client = ar1021->client;
  87
  88         disable_irq(client->irq);
  89 }
  90
  91 static int ar1021_i2c_probe(struct i2c_client *client,
  92                             const struct i2c_device_id *id)
  93 {
  94         struct ar1021_i2c *ar1021;
  95         struct input_dev *input;
  96         int error;
  97
  98         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
  99                 dev_err(&client->dev, "i2c_check_functionality error\n");
 100                 return -ENXIO;
 101         }
 102
 103         ar1021 = devm_kzalloc(&client->dev, sizeof(*ar1021), GFP_KERNEL);
 104         if (!ar1021)
 105                 return -ENOMEM;
 106
 107         input = devm_input_allocate_device(&client->dev);
 108         if (!input)
 109                 return -ENOMEM;
 110
 111         ar1021->client = client;
 112         ar1021->input = input;
 113
 114         input->name = "ar1021 I2C Touchscreen";
 115         input->id.bustype = BUS_I2C;
 116         input->dev.parent = &client->dev;
 117         input->open = ar1021_i2c_open;
 118         input->close = ar1021_i2c_close;
 119
 120         input_set_capability(input, EV_KEY, BTN_TOUCH);
 121         input_set_abs_params(input, ABS_X, 0, AR1021_MAX_X, 0, 0);
 122         input_set_abs_params(input, ABS_Y, 0, AR1021_MAX_Y, 0, 0);
 123
 124         input_set_drvdata(input, ar1021);
 125
 126         error = devm_request_threaded_irq(&client->dev, client->irq,
 127                                           NULL, ar1021_i2c_irq,
 128                                           IRQF_ONESHOT,
 129                                           "ar1021_i2c", ar1021);
 130         if (error) {
 131                 dev_err(&client->dev,
 132                         "Failed to enable IRQ, error: %d\n", error);
 133                 return error;
 134         }
 135
 136         /* Disable the IRQ, we'll enable it in ar1021_i2c_open() */
 137         disable_irq(client->irq);
 138
 139         error = input_register_device(ar1021->input);
 140         if (error) {
 141                 dev_err(&client->dev,
 142                         "Failed to register input device, error: %d\n", error);
 143                 return error;
 144         }
 145
 146         return 0;
 147 }
 148
 149 static int __maybe_unused ar1021_i2c_suspend(struct device *dev)
 150 {
 151         struct i2c_client *client = to_i2c_client(dev);
 152
 153         disable_irq(client->irq);
 154
 155         return 0;
 156 }
 157
 158 static int __maybe_unused ar1021_i2c_resume(struct device *dev)
 159 {
 160         struct i2c_client *client = to_i2c_client(dev);
 161
 162         enable_irq(client->irq);
 163
 164         return 0;
 165 }
 166
 167 static SIMPLE_DEV_PM_OPS(ar1021_i2c_pm, ar1021_i2c_suspend, ar1021_i2c_resume);
 168
 169 static const struct i2c_device_id ar1021_i2c_id[] = {
 170         { "ar1021", 0 },
 171         { },
 172 };
 173 MODULE_DEVICE_TABLE(i2c, ar1021_i2c_id);
 174
 175 static const struct of_device_id ar1021_i2c_of_match[] = {
 176         { .compatible = "microchip,ar1021-i2c", },
 177         { }
 178 };
 179 MODULE_DEVICE_TABLE(of, ar1021_i2c_of_match);
 180
 181 static struct i2c_driver ar1021_i2c_driver = {
 182         .driver = {
 183                 .name   = "ar1021_i2c",
 184                 .pm     = &ar1021_i2c_pm,
 185                 .of_match_table = ar1021_i2c_of_match,
 186         },
 187
 188         .probe          = ar1021_i2c_probe,
 189         .id_table       = ar1021_i2c_id,
 190 };
 191 module_i2c_driver(ar1021_i2c_driver);
 192
 193 MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>");
 194 MODULE_DESCRIPTION("Microchip AR1020 and AR1021 I2C Driver");
 195 MODULE_LICENSE("GPL");