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 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 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 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 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 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