| 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"); |