1 /* 2 * AD714X CapTouch Programmable Controller driver (SPI bus) 3 * 4 * Copyright 2009 Analog Devices Inc. 5 * 6 * Licensed under the GPL-2 or later. 7 */ 8 9 #include <linux/input.h> /* BUS_I2C */ 10 #include <linux/module.h> 11 #include <linux/spi/spi.h> 12 #include <linux/pm.h> 13 #include <linux/types.h> 14 #include "ad714x.h" 15 16 #define AD714x_SPI_CMD_PREFIX 0xE000 /* bits 15:11 */ 17 #define AD714x_SPI_READ BIT(10) 18 19 #ifdef CONFIG_PM 20 static int ad714x_spi_suspend(struct device *dev) 21 { 22 return ad714x_disable(spi_get_drvdata(to_spi_device(dev))); 23 } 24 25 static int ad714x_spi_resume(struct device *dev) 26 { 27 return ad714x_enable(spi_get_drvdata(to_spi_device(dev))); 28 } 29 #endif 30 31 static SIMPLE_DEV_PM_OPS(ad714x_spi_pm, ad714x_spi_suspend, ad714x_spi_resume); 32 33 static int ad714x_spi_read(struct device *dev, unsigned short reg, 34 unsigned short *data) 35 { 36 struct spi_device *spi = to_spi_device(dev); 37 unsigned short tx = AD714x_SPI_CMD_PREFIX | AD714x_SPI_READ | reg; 38 39 return spi_write_then_read(spi, (u8 *)&tx, 2, (u8 *)data, 2); 40 } 41 42 static int ad714x_spi_write(struct device *dev, unsigned short reg, 43 unsigned short data) 44 { 45 struct spi_device *spi = to_spi_device(dev); 46 unsigned short tx[2] = { 47 AD714x_SPI_CMD_PREFIX | reg, 48 data 49 }; 50 51 return spi_write(spi, (u8 *)tx, 4); 52 } 53 54 static int __devinit ad714x_spi_probe(struct spi_device *spi) 55 { 56 struct ad714x_chip *chip; 57 int err; 58 59 spi->bits_per_word = 8; 60 err = spi_setup(spi); 61 if (err < 0) 62 return err; 63 64 chip = ad714x_probe(&spi->dev, BUS_SPI, spi->irq, 65 ad714x_spi_read, ad714x_spi_write); 66 if (IS_ERR(chip)) 67 return PTR_ERR(chip); 68 69 spi_set_drvdata(spi, chip); 70 71 return 0; 72 } 73 74 static int __devexit ad714x_spi_remove(struct spi_device *spi) 75 { 76 struct ad714x_chip *chip = spi_get_drvdata(spi); 77 78 ad714x_remove(chip); 79 spi_set_drvdata(spi, NULL); 80 81 return 0; 82 } 83 84 static struct spi_driver ad714x_spi_driver = { 85 .driver = { 86 .name = "ad714x_captouch", 87 .owner = THIS_MODULE, 88 .pm = &ad714x_spi_pm, 89 }, 90 .probe = ad714x_spi_probe, 91 .remove = __devexit_p(ad714x_spi_remove), 92 }; 93 94 static __init int ad714x_spi_init(void) 95 { 96 return spi_register_driver(&ad714x_spi_driver); 97 } 98 module_init(ad714x_spi_init); 99 100 static __exit void ad714x_spi_exit(void) 101 { 102 spi_unregister_driver(&ad714x_spi_driver); 103 } 104 module_exit(ad714x_spi_exit); 105 106 MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor SPI Bus Driver"); 107 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>"); 108 MODULE_LICENSE("GPL"); 109