1 /* 2 * STMicroelectronics hts221 i2c driver 3 * 4 * Copyright 2016 STMicroelectronics Inc. 5 * 6 * Lorenzo Bianconi <lorenzo.bianconi@st.com> 7 * 8 * Licensed under the GPL-2. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/acpi.h> 14 #include <linux/i2c.h> 15 #include <linux/slab.h> 16 #include "hts221.h" 17 18 #define I2C_AUTO_INCREMENT 0x80 19 20 static int hts221_i2c_read(struct device *dev, u8 addr, int len, u8 *data) 21 { 22 struct i2c_msg msg[2]; 23 struct i2c_client *client = to_i2c_client(dev); 24 25 if (len > 1) 26 addr |= I2C_AUTO_INCREMENT; 27 28 msg[0].addr = client->addr; 29 msg[0].flags = client->flags; 30 msg[0].len = 1; 31 msg[0].buf = &addr; 32 33 msg[1].addr = client->addr; 34 msg[1].flags = client->flags | I2C_M_RD; 35 msg[1].len = len; 36 msg[1].buf = data; 37 38 return i2c_transfer(client->adapter, msg, 2); 39 } 40 41 static int hts221_i2c_write(struct device *dev, u8 addr, int len, u8 *data) 42 { 43 u8 send[len + 1]; 44 struct i2c_msg msg; 45 struct i2c_client *client = to_i2c_client(dev); 46 47 if (len > 1) 48 addr |= I2C_AUTO_INCREMENT; 49 50 send[0] = addr; 51 memcpy(&send[1], data, len * sizeof(u8)); 52 53 msg.addr = client->addr; 54 msg.flags = client->flags; 55 msg.len = len + 1; 56 msg.buf = send; 57 58 return i2c_transfer(client->adapter, &msg, 1); 59 } 60 61 static const struct hts221_transfer_function hts221_transfer_fn = { 62 .read = hts221_i2c_read, 63 .write = hts221_i2c_write, 64 }; 65 66 static int hts221_i2c_probe(struct i2c_client *client, 67 const struct i2c_device_id *id) 68 { 69 struct hts221_hw *hw; 70 struct iio_dev *iio_dev; 71 72 iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*hw)); 73 if (!iio_dev) 74 return -ENOMEM; 75 76 i2c_set_clientdata(client, iio_dev); 77 78 hw = iio_priv(iio_dev); 79 hw->name = client->name; 80 hw->dev = &client->dev; 81 hw->irq = client->irq; 82 hw->tf = &hts221_transfer_fn; 83 84 return hts221_probe(iio_dev); 85 } 86 87 static const struct acpi_device_id hts221_acpi_match[] = { 88 {"SMO9100", 0}, 89 { }, 90 }; 91 MODULE_DEVICE_TABLE(acpi, hts221_acpi_match); 92 93 static const struct of_device_id hts221_i2c_of_match[] = { 94 { .compatible = "st,hts221", }, 95 {}, 96 }; 97 MODULE_DEVICE_TABLE(of, hts221_i2c_of_match); 98 99 static const struct i2c_device_id hts221_i2c_id_table[] = { 100 { HTS221_DEV_NAME }, 101 {}, 102 }; 103 MODULE_DEVICE_TABLE(i2c, hts221_i2c_id_table); 104 105 static struct i2c_driver hts221_driver = { 106 .driver = { 107 .name = "hts221_i2c", 108 .pm = &hts221_pm_ops, 109 .of_match_table = of_match_ptr(hts221_i2c_of_match), 110 .acpi_match_table = ACPI_PTR(hts221_acpi_match), 111 }, 112 .probe = hts221_i2c_probe, 113 .id_table = hts221_i2c_id_table, 114 }; 115 module_i2c_driver(hts221_driver); 116 117 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>"); 118 MODULE_DESCRIPTION("STMicroelectronics hts221 i2c driver"); 119 MODULE_LICENSE("GPL v2"); 120