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/types.h> 13 #include "ad714x.h" 14 15 #define AD714x_SPI_CMD_PREFIX 0xE000 /* bits 15:11 */ 16 #define AD714x_SPI_READ BIT(10) 17 18 #ifdef CONFIG_PM 19 static int ad714x_spi_suspend(struct spi_device *spi, pm_message_t message) 20 { 21 return ad714x_disable(spi_get_drvdata(spi)); 22 } 23 24 static int ad714x_spi_resume(struct spi_device *spi) 25 { 26 return ad714x_enable(spi_get_drvdata(spi)); 27 } 28 #else 29 # define ad714x_spi_suspend NULL 30 # define ad714x_spi_resume NULL 31 #endif 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 58 chip = ad714x_probe(&spi->dev, BUS_SPI, spi->irq, 59 ad714x_spi_read, ad714x_spi_write); 60 if (IS_ERR(chip)) 61 return PTR_ERR(chip); 62 63 spi_set_drvdata(spi, chip); 64 65 return 0; 66 } 67 68 static int __devexit ad714x_spi_remove(struct spi_device *spi) 69 { 70 struct ad714x_chip *chip = spi_get_drvdata(spi); 71 72 ad714x_remove(chip); 73 spi_set_drvdata(spi, NULL); 74 75 return 0; 76 } 77 78 static struct spi_driver ad714x_spi_driver = { 79 .driver = { 80 .name = "ad714x_captouch", 81 .owner = THIS_MODULE, 82 }, 83 .probe = ad714x_spi_probe, 84 .remove = __devexit_p(ad714x_spi_remove), 85 .suspend = ad714x_spi_suspend, 86 .resume = ad714x_spi_resume, 87 }; 88 89 static __init int ad714x_spi_init(void) 90 { 91 return spi_register_driver(&ad714x_spi_driver); 92 } 93 module_init(ad714x_spi_init); 94 95 static __exit void ad714x_spi_exit(void) 96 { 97 spi_unregister_driver(&ad714x_spi_driver); 98 } 99 module_exit(ad714x_spi_exit); 100 101 MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor SPI Bus Driver"); 102 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>"); 103 MODULE_LICENSE("GPL"); 104