/* * AD714X CapTouch Programmable Controller driver (SPI bus) * * Copyright 2009-2011 Analog Devices Inc. * * Licensed under the GPL-2 or later. */ #include <linux/input.h> /* BUS_SPI */ #include <linux/module.h> #include <linux/spi/spi.h> #include <linux/pm.h> #include <linux/types.h> #include "ad714x.h" #define AD714x_SPI_CMD_PREFIX 0xE000 /* bits 15:11 */ #define AD714x_SPI_READ BIT(10) static int __maybe_unused ad714x_spi_suspend(struct device *dev) { return ad714x_disable(spi_get_drvdata(to_spi_device(dev))); } static int __maybe_unused ad714x_spi_resume(struct device *dev) { return ad714x_enable(spi_get_drvdata(to_spi_device(dev))); } static SIMPLE_DEV_PM_OPS(ad714x_spi_pm, ad714x_spi_suspend, ad714x_spi_resume); static int ad714x_spi_read(struct ad714x_chip *chip, unsigned short reg, unsigned short *data, size_t len) { struct spi_device *spi = to_spi_device(chip->dev); struct spi_message message; struct spi_transfer xfer[2]; int i; int error; spi_message_init(&message); memset(xfer, 0, sizeof(xfer)); chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX | AD714x_SPI_READ | reg); xfer[0].tx_buf = &chip->xfer_buf[0]; xfer[0].len = sizeof(chip->xfer_buf[0]); spi_message_add_tail(&xfer[0], &message); xfer[1].rx_buf = &chip->xfer_buf[1]; xfer[1].len = sizeof(chip->xfer_buf[1]) * len; spi_message_add_tail(&xfer[1], &message); error = spi_sync(spi, &message); if (unlikely(error)) { dev_err(chip->dev, "SPI read error: %d\n", error); return error; } for (i = 0; i < len; i++) data[i] = be16_to_cpu(chip->xfer_buf[i + 1]); return 0; } static int ad714x_spi_write(struct ad714x_chip *chip, unsigned short reg, unsigned short data) { struct spi_device *spi = to_spi_device(chip->dev); int error; chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX | reg); chip->xfer_buf[1] = cpu_to_be16(data); error = spi_write(spi, (u8 *)chip->xfer_buf, 2 * sizeof(*chip->xfer_buf)); if (unlikely(error)) { dev_err(chip->dev, "SPI write error: %d\n", error); return error; } return 0; } static int ad714x_spi_probe(struct spi_device *spi) { struct ad714x_chip *chip; int err; spi->bits_per_word = 8; err = spi_setup(spi); if (err < 0) return err; chip = ad714x_probe(&spi->dev, BUS_SPI, spi->irq, ad714x_spi_read, ad714x_spi_write); if (IS_ERR(chip)) return PTR_ERR(chip); spi_set_drvdata(spi, chip); return 0; } static int ad714x_spi_remove(struct spi_device *spi) { struct ad714x_chip *chip = spi_get_drvdata(spi); ad714x_remove(chip); return 0; } static struct spi_driver ad714x_spi_driver = { .driver = { .name = "ad714x_captouch", .owner = THIS_MODULE, .pm = &ad714x_spi_pm, }, .probe = ad714x_spi_probe, .remove = ad714x_spi_remove, }; module_spi_driver(ad714x_spi_driver); MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor SPI Bus Driver"); MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>"); MODULE_LICENSE("GPL");