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"); 196