1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Microchip AR1020 and AR1021 driver for I2C 4 * 5 * Author: Christian Gmeiner <christian.gmeiner@gmail.com> 6 */ 7 8 #include <linux/bitops.h> 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_TOUCH_PKG_SIZE 5 17 18 #define AR1021_MAX_X 4095 19 #define AR1021_MAX_Y 4095 20 21 #define AR1021_CMD 0x55 22 23 #define AR1021_CMD_ENABLE_TOUCH 0x12 24 25 struct ar1021_i2c { 26 struct i2c_client *client; 27 struct input_dev *input; 28 u8 data[AR1021_TOUCH_PKG_SIZE]; 29 }; 30 31 static irqreturn_t ar1021_i2c_irq(int irq, void *dev_id) 32 { 33 struct ar1021_i2c *ar1021 = dev_id; 34 struct input_dev *input = ar1021->input; 35 u8 *data = ar1021->data; 36 unsigned int x, y, button; 37 int retval; 38 39 retval = i2c_master_recv(ar1021->client, 40 ar1021->data, sizeof(ar1021->data)); 41 if (retval != sizeof(ar1021->data)) 42 goto out; 43 44 /* sync bit set ? */ 45 if (!(data[0] & BIT(7))) 46 goto out; 47 48 button = data[0] & BIT(0); 49 x = ((data[2] & 0x1f) << 7) | (data[1] & 0x7f); 50 y = ((data[4] & 0x1f) << 7) | (data[3] & 0x7f); 51 52 input_report_abs(input, ABS_X, x); 53 input_report_abs(input, ABS_Y, y); 54 input_report_key(input, BTN_TOUCH, button); 55 input_sync(input); 56 57 out: 58 return IRQ_HANDLED; 59 } 60 61 static int ar1021_i2c_open(struct input_dev *dev) 62 { 63 static const u8 cmd_enable_touch[] = { 64 AR1021_CMD, 65 0x01, /* number of bytes after this */ 66 AR1021_CMD_ENABLE_TOUCH 67 }; 68 struct ar1021_i2c *ar1021 = input_get_drvdata(dev); 69 struct i2c_client *client = ar1021->client; 70 int error; 71 72 error = i2c_master_send(ar1021->client, cmd_enable_touch, 73 sizeof(cmd_enable_touch)); 74 if (error < 0) 75 return error; 76 77 enable_irq(client->irq); 78 79 return 0; 80 } 81 82 static void ar1021_i2c_close(struct input_dev *dev) 83 { 84 struct ar1021_i2c *ar1021 = input_get_drvdata(dev); 85 struct i2c_client *client = ar1021->client; 86 87 disable_irq(client->irq); 88 } 89 90 static int ar1021_i2c_probe(struct i2c_client *client) 91 { 92 struct ar1021_i2c *ar1021; 93 struct input_dev *input; 94 int error; 95 96 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 97 dev_err(&client->dev, "i2c_check_functionality error\n"); 98 return -ENXIO; 99 } 100 101 ar1021 = devm_kzalloc(&client->dev, sizeof(*ar1021), GFP_KERNEL); 102 if (!ar1021) 103 return -ENOMEM; 104 105 input = devm_input_allocate_device(&client->dev); 106 if (!input) 107 return -ENOMEM; 108 109 ar1021->client = client; 110 ar1021->input = input; 111 112 input->name = "ar1021 I2C Touchscreen"; 113 input->id.bustype = BUS_I2C; 114 input->dev.parent = &client->dev; 115 input->open = ar1021_i2c_open; 116 input->close = ar1021_i2c_close; 117 118 __set_bit(INPUT_PROP_DIRECT, input->propbit); 119 input_set_capability(input, EV_KEY, BTN_TOUCH); 120 input_set_abs_params(input, ABS_X, 0, AR1021_MAX_X, 0, 0); 121 input_set_abs_params(input, ABS_Y, 0, AR1021_MAX_Y, 0, 0); 122 123 input_set_drvdata(input, ar1021); 124 125 error = devm_request_threaded_irq(&client->dev, client->irq, 126 NULL, ar1021_i2c_irq, 127 IRQF_ONESHOT | IRQF_NO_AUTOEN, 128 "ar1021_i2c", ar1021); 129 if (error) { 130 dev_err(&client->dev, 131 "Failed to enable IRQ, error: %d\n", error); 132 return error; 133 } 134 135 error = input_register_device(ar1021->input); 136 if (error) { 137 dev_err(&client->dev, 138 "Failed to register input device, error: %d\n", error); 139 return error; 140 } 141 142 return 0; 143 } 144 145 static int ar1021_i2c_suspend(struct device *dev) 146 { 147 struct i2c_client *client = to_i2c_client(dev); 148 149 disable_irq(client->irq); 150 151 return 0; 152 } 153 154 static int ar1021_i2c_resume(struct device *dev) 155 { 156 struct i2c_client *client = to_i2c_client(dev); 157 158 enable_irq(client->irq); 159 160 return 0; 161 } 162 163 static DEFINE_SIMPLE_DEV_PM_OPS(ar1021_i2c_pm, 164 ar1021_i2c_suspend, ar1021_i2c_resume); 165 166 static const struct i2c_device_id ar1021_i2c_id[] = { 167 { "ar1021" }, 168 { } 169 }; 170 MODULE_DEVICE_TABLE(i2c, ar1021_i2c_id); 171 172 static const struct of_device_id ar1021_i2c_of_match[] = { 173 { .compatible = "microchip,ar1021-i2c", }, 174 { } 175 }; 176 MODULE_DEVICE_TABLE(of, ar1021_i2c_of_match); 177 178 static struct i2c_driver ar1021_i2c_driver = { 179 .driver = { 180 .name = "ar1021_i2c", 181 .pm = pm_sleep_ptr(&ar1021_i2c_pm), 182 .of_match_table = ar1021_i2c_of_match, 183 }, 184 185 .probe = ar1021_i2c_probe, 186 .id_table = ar1021_i2c_id, 187 }; 188 module_i2c_driver(ar1021_i2c_driver); 189 190 MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>"); 191 MODULE_DESCRIPTION("Microchip AR1020 and AR1021 I2C Driver"); 192 MODULE_LICENSE("GPL"); 193