1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * ADLX345/346 Three-Axis Digital Accelerometers (SPI Interface)
4 *
5 * Enter bugs at http://blackfin.uclinux.org/
6 *
7 * Copyright (C) 2009 Michael Hennerich, Analog Devices Inc.
8 */
9
10 #include <linux/input.h> /* BUS_SPI */
11 #include <linux/module.h>
12 #include <linux/spi/spi.h>
13 #include <linux/pm.h>
14 #include <linux/types.h>
15 #include "adxl34x.h"
16
17 #define MAX_SPI_FREQ_HZ 5000000
18 #define MAX_FREQ_NO_FIFODELAY 1500000
19 #define ADXL34X_CMD_MULTB (1 << 6)
20 #define ADXL34X_CMD_READ (1 << 7)
21 #define ADXL34X_WRITECMD(reg) (reg & 0x3F)
22 #define ADXL34X_READCMD(reg) (ADXL34X_CMD_READ | (reg & 0x3F))
23 #define ADXL34X_READMB_CMD(reg) (ADXL34X_CMD_READ | ADXL34X_CMD_MULTB \
24 | (reg & 0x3F))
25
adxl34x_spi_read(struct device * dev,unsigned char reg)26 static int adxl34x_spi_read(struct device *dev, unsigned char reg)
27 {
28 struct spi_device *spi = to_spi_device(dev);
29 unsigned char cmd;
30
31 cmd = ADXL34X_READCMD(reg);
32
33 return spi_w8r8(spi, cmd);
34 }
35
adxl34x_spi_write(struct device * dev,unsigned char reg,unsigned char val)36 static int adxl34x_spi_write(struct device *dev,
37 unsigned char reg, unsigned char val)
38 {
39 struct spi_device *spi = to_spi_device(dev);
40 unsigned char buf[2];
41
42 buf[0] = ADXL34X_WRITECMD(reg);
43 buf[1] = val;
44
45 return spi_write(spi, buf, sizeof(buf));
46 }
47
adxl34x_spi_read_block(struct device * dev,unsigned char reg,int count,void * buf)48 static int adxl34x_spi_read_block(struct device *dev,
49 unsigned char reg, int count,
50 void *buf)
51 {
52 struct spi_device *spi = to_spi_device(dev);
53 ssize_t status;
54
55 reg = ADXL34X_READMB_CMD(reg);
56 status = spi_write_then_read(spi, ®, 1, buf, count);
57
58 return (status < 0) ? status : 0;
59 }
60
61 static const struct adxl34x_bus_ops adxl34x_spi_bops = {
62 .bustype = BUS_SPI,
63 .write = adxl34x_spi_write,
64 .read = adxl34x_spi_read,
65 .read_block = adxl34x_spi_read_block,
66 };
67
adxl34x_spi_probe(struct spi_device * spi)68 static int adxl34x_spi_probe(struct spi_device *spi)
69 {
70 struct adxl34x *ac;
71
72 /* don't exceed max specified SPI CLK frequency */
73 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
74 dev_err(&spi->dev, "SPI CLK %d Hz too fast\n", spi->max_speed_hz);
75 return -EINVAL;
76 }
77
78 ac = adxl34x_probe(&spi->dev, spi->irq,
79 spi->max_speed_hz > MAX_FREQ_NO_FIFODELAY,
80 &adxl34x_spi_bops);
81
82 if (IS_ERR(ac))
83 return PTR_ERR(ac);
84
85 spi_set_drvdata(spi, ac);
86
87 return 0;
88 }
89
adxl34x_spi_remove(struct spi_device * spi)90 static void adxl34x_spi_remove(struct spi_device *spi)
91 {
92 struct adxl34x *ac = spi_get_drvdata(spi);
93
94 adxl34x_remove(ac);
95 }
96
97 static struct spi_driver adxl34x_driver = {
98 .driver = {
99 .name = "adxl34x",
100 .pm = pm_sleep_ptr(&adxl34x_pm),
101 },
102 .probe = adxl34x_spi_probe,
103 .remove = adxl34x_spi_remove,
104 };
105
106 module_spi_driver(adxl34x_driver);
107
108 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
109 MODULE_DESCRIPTION("ADXL345/346 Three-Axis Digital Accelerometer SPI Bus Driver");
110 MODULE_LICENSE("GPL");
111