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/types.h> 14 #include "adxl34x.h" 15 16 #define MAX_SPI_FREQ_HZ 5000000 17 #define MAX_FREQ_NO_FIFODELAY 1500000 18 #define ADXL34X_CMD_MULTB (1 << 6) 19 #define ADXL34X_CMD_READ (1 << 7) 20 #define ADXL34X_WRITECMD(reg) (reg & 0x3F) 21 #define ADXL34X_READCMD(reg) (ADXL34X_CMD_READ | (reg & 0x3F)) 22 #define ADXL34X_READMB_CMD(reg) (ADXL34X_CMD_READ | ADXL34X_CMD_MULTB \ 23 | (reg & 0x3F)) 24 25 static int adxl34x_spi_read(struct device *dev, unsigned char reg) 26 { 27 struct spi_device *spi = to_spi_device(dev); 28 unsigned char cmd; 29 30 cmd = ADXL34X_READCMD(reg); 31 32 return spi_w8r8(spi, cmd); 33 } 34 35 static int adxl34x_spi_write(struct device *dev, 36 unsigned char reg, unsigned char val) 37 { 38 struct spi_device *spi = to_spi_device(dev); 39 unsigned char buf[2]; 40 41 buf[0] = ADXL34X_WRITECMD(reg); 42 buf[1] = val; 43 44 return spi_write(spi, buf, sizeof(buf)); 45 } 46 47 static int adxl34x_spi_read_block(struct device *dev, 48 unsigned char reg, int count, 49 void *buf) 50 { 51 struct spi_device *spi = to_spi_device(dev); 52 ssize_t status; 53 54 reg = ADXL34X_READMB_CMD(reg); 55 status = spi_write_then_read(spi, ®, 1, buf, count); 56 57 return (status < 0) ? status : 0; 58 } 59 60 static const struct adxl34x_bus_ops adx134x_spi_bops = { 61 .bustype = BUS_SPI, 62 .write = adxl34x_spi_write, 63 .read = adxl34x_spi_read, 64 .read_block = adxl34x_spi_read_block, 65 }; 66 67 static int __devinit adxl34x_spi_probe(struct spi_device *spi) 68 { 69 struct adxl34x *ac; 70 71 /* don't exceed max specified SPI CLK frequency */ 72 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) { 73 dev_err(&spi->dev, "SPI CLK %d Hz too fast\n", spi->max_speed_hz); 74 return -EINVAL; 75 } 76 77 ac = adxl34x_probe(&spi->dev, spi->irq, 78 spi->max_speed_hz > MAX_FREQ_NO_FIFODELAY, 79 &adx134x_spi_bops); 80 81 if (IS_ERR(ac)) 82 return PTR_ERR(ac); 83 84 spi_set_drvdata(spi, ac); 85 86 return 0; 87 } 88 89 static int __devexit adxl34x_spi_remove(struct spi_device *spi) 90 { 91 struct adxl34x *ac = dev_get_drvdata(&spi->dev); 92 93 return adxl34x_remove(ac); 94 } 95 96 #ifdef CONFIG_PM 97 static int adxl34x_spi_suspend(struct spi_device *spi, pm_message_t message) 98 { 99 struct adxl34x *ac = dev_get_drvdata(&spi->dev); 100 101 adxl34x_suspend(ac); 102 103 return 0; 104 } 105 106 static int adxl34x_spi_resume(struct spi_device *spi) 107 { 108 struct adxl34x *ac = dev_get_drvdata(&spi->dev); 109 110 adxl34x_resume(ac); 111 112 return 0; 113 } 114 #else 115 # define adxl34x_spi_suspend NULL 116 # define adxl34x_spi_resume NULL 117 #endif 118 119 static struct spi_driver adxl34x_driver = { 120 .driver = { 121 .name = "adxl34x", 122 .bus = &spi_bus_type, 123 .owner = THIS_MODULE, 124 }, 125 .probe = adxl34x_spi_probe, 126 .remove = __devexit_p(adxl34x_spi_remove), 127 .suspend = adxl34x_spi_suspend, 128 .resume = adxl34x_spi_resume, 129 }; 130 131 static int __init adxl34x_spi_init(void) 132 { 133 return spi_register_driver(&adxl34x_driver); 134 } 135 module_init(adxl34x_spi_init); 136 137 static void __exit adxl34x_spi_exit(void) 138 { 139 spi_unregister_driver(&adxl34x_driver); 140 } 141 module_exit(adxl34x_spi_exit); 142 143 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 144 MODULE_DESCRIPTION("ADXL345/346 Three-Axis Digital Accelerometer SPI Bus Driver"); 145 MODULE_LICENSE("GPL"); 146