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 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"); 181