1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * STMicroelectronics st_lsm6dsr spi driver
4 *
5 * Copyright 2020 STMicroelectronics Inc.
6 *
7 * Lorenzo Bianconi <lorenzo.bianconi@st.com>
8 *
9 * Licensed under the GPL-2.
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/spi/spi.h>
15 #include <linux/slab.h>
16 #include <linux/of.h>
17
18 #include "st_lsm6dsr.h"
19
20 #define SENSORS_SPI_READ BIT(7)
21
st_lsm6dsr_spi_read(struct device * dev,u8 addr,int len,u8 * data)22 static int st_lsm6dsr_spi_read(struct device *dev, u8 addr, int len,
23 u8 *data)
24 {
25 struct spi_device *spi = to_spi_device(dev);
26 struct st_lsm6dsr_hw *hw = spi_get_drvdata(spi);
27 int err;
28
29 struct spi_transfer xfers[] = {
30 {
31 .tx_buf = hw->tb.tx_buf,
32 .bits_per_word = 8,
33 .len = 1,
34 },
35 {
36 .rx_buf = hw->tb.rx_buf,
37 .bits_per_word = 8,
38 .len = len,
39 }
40 };
41
42 hw->tb.tx_buf[0] = addr | SENSORS_SPI_READ;
43
44 err = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers));
45 if (err < 0)
46 return err;
47
48 memcpy(data, hw->tb.rx_buf, len * sizeof(u8));
49
50 return len;
51 }
52
st_lsm6dsr_spi_write(struct device * dev,u8 addr,int len,const u8 * data)53 static int st_lsm6dsr_spi_write(struct device *dev, u8 addr, int len,
54 const u8 *data)
55 {
56 struct st_lsm6dsr_hw *hw;
57 struct spi_device *spi;
58
59 if (len >= ST_LSM6DSR_TX_MAX_LENGTH)
60 return -ENOMEM;
61
62 spi = to_spi_device(dev);
63 hw = spi_get_drvdata(spi);
64
65 hw->tb.tx_buf[0] = addr;
66 memcpy(&hw->tb.tx_buf[1], data, len);
67
68 return spi_write(spi, hw->tb.tx_buf, len + 1);
69 }
70
71 static const struct st_lsm6dsr_transfer_function st_lsm6dsr_transfer_fn = {
72 .read = st_lsm6dsr_spi_read,
73 .write = st_lsm6dsr_spi_write,
74 };
75
st_lsm6dsr_spi_probe(struct spi_device * spi)76 static int st_lsm6dsr_spi_probe(struct spi_device *spi)
77 {
78 return st_lsm6dsr_probe(&spi->dev, spi->irq,
79 &st_lsm6dsr_transfer_fn);
80 }
81
st_lsm6dsr_spi_remove(struct spi_device * spi)82 static int st_lsm6dsr_spi_remove(struct spi_device *spi)
83 {
84 return st_lsm6dsr_remove(&spi->dev);
85 }
86
87 static const struct of_device_id st_lsm6dsr_spi_of_match[] = {
88 {
89 .compatible = "st,lsm6dsr",
90 },
91 {},
92 };
93 MODULE_DEVICE_TABLE(of, st_lsm6dsr_spi_of_match);
94
95 static const struct spi_device_id st_lsm6dsr_spi_id_table[] = {
96 { ST_LSM6DSR_DEV_NAME },
97 {},
98 };
99 MODULE_DEVICE_TABLE(spi, st_lsm6dsr_spi_id_table);
100
101 static struct spi_driver st_lsm6dsr_driver = {
102 .driver = {
103 .name = "st_lsm6dsr_spi",
104 .pm = &st_lsm6dsr_pm_ops,
105 .of_match_table = of_match_ptr(st_lsm6dsr_spi_of_match),
106 },
107 .probe = st_lsm6dsr_spi_probe,
108 .remove = st_lsm6dsr_spi_remove,
109 .id_table = st_lsm6dsr_spi_id_table,
110 };
111 module_spi_driver(st_lsm6dsr_driver);
112
113 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
114 MODULE_DESCRIPTION("STMicroelectronics st_lsm6dsr spi driver");
115 MODULE_LICENSE("GPL");
116