1 /* 2 * ADLX345/346 Three-Axis Digital Accelerometers (SPI Interface) 3 * 4 * Enter bugs at http://blackfin.uclinux.org/ 5 * 6 * Copyright (C) 2009 Michael Hennerich, Analog Devices Inc. 7 * Licensed under the GPL-2 or later. 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 __devinit 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 int __devexit adxl34x_spi_remove(struct spi_device *spi) 91 { 92 struct adxl34x *ac = dev_get_drvdata(&spi->dev); 93 94 return adxl34x_remove(ac); 95 } 96 97 #ifdef CONFIG_PM 98 static int adxl34x_spi_suspend(struct device *dev) 99 { 100 struct spi_device *spi = to_spi_device(dev); 101 struct adxl34x *ac = dev_get_drvdata(&spi->dev); 102 103 adxl34x_suspend(ac); 104 105 return 0; 106 } 107 108 static int adxl34x_spi_resume(struct device *dev) 109 { 110 struct spi_device *spi = to_spi_device(dev); 111 struct adxl34x *ac = dev_get_drvdata(&spi->dev); 112 113 adxl34x_resume(ac); 114 115 return 0; 116 } 117 #endif 118 119 static SIMPLE_DEV_PM_OPS(adxl34x_spi_pm, adxl34x_spi_suspend, 120 adxl34x_spi_resume); 121 122 static struct spi_driver adxl34x_driver = { 123 .driver = { 124 .name = "adxl34x", 125 .owner = THIS_MODULE, 126 .pm = &adxl34x_spi_pm, 127 }, 128 .probe = adxl34x_spi_probe, 129 .remove = __devexit_p(adxl34x_spi_remove), 130 }; 131 132 module_spi_driver(adxl34x_driver); 133 134 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 135 MODULE_DESCRIPTION("ADXL345/346 Three-Axis Digital Accelerometer SPI Bus Driver"); 136 MODULE_LICENSE("GPL"); 137