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9eff794b77
The interrupt status registers should be read in row to avoid invalid data. Alter "read" method for both bus options to allow reading several registers in a row and make sure we read interrupt status registers properly. Read sequence saves 50% of bus transactions compared to single register reads. So use it also for the result registers, which are also located in a row. Also update copyright notice. Signed-off-by: Michael Hennerich <michael.hennerich@analog.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
141 lines
3.2 KiB
C
141 lines
3.2 KiB
C
/*
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* AD714X CapTouch Programmable Controller driver (SPI bus)
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*
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* Copyright 2009-2011 Analog Devices Inc.
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*
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* Licensed under the GPL-2 or later.
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*/
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#include <linux/input.h> /* BUS_SPI */
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#include <linux/module.h>
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#include <linux/spi/spi.h>
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#include <linux/pm.h>
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#include <linux/types.h>
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#include "ad714x.h"
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#define AD714x_SPI_CMD_PREFIX 0xE000 /* bits 15:11 */
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#define AD714x_SPI_READ BIT(10)
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#ifdef CONFIG_PM
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static int ad714x_spi_suspend(struct device *dev)
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{
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return ad714x_disable(spi_get_drvdata(to_spi_device(dev)));
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}
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static int ad714x_spi_resume(struct device *dev)
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{
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return ad714x_enable(spi_get_drvdata(to_spi_device(dev)));
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}
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#endif
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static SIMPLE_DEV_PM_OPS(ad714x_spi_pm, ad714x_spi_suspend, ad714x_spi_resume);
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static int ad714x_spi_read(struct ad714x_chip *chip,
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unsigned short reg, unsigned short *data, size_t len)
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{
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struct spi_device *spi = to_spi_device(chip->dev);
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struct spi_message message;
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struct spi_transfer xfer[2];
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int i;
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int error;
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spi_message_init(&message);
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memset(xfer, 0, sizeof(xfer));
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chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX |
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AD714x_SPI_READ | reg);
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xfer[0].tx_buf = &chip->xfer_buf[0];
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xfer[0].len = sizeof(chip->xfer_buf[0]);
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spi_message_add_tail(&xfer[0], &message);
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xfer[1].rx_buf = &chip->xfer_buf[1];
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xfer[1].len = sizeof(chip->xfer_buf[1]) * len;
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spi_message_add_tail(&xfer[1], &message);
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error = spi_sync(spi, &message);
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if (unlikely(error)) {
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dev_err(chip->dev, "SPI read error: %d\n", error);
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return error;
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}
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for (i = 0; i < len; i++)
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data[i] = be16_to_cpu(chip->xfer_buf[i + 1]);
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return 0;
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}
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static int ad714x_spi_write(struct ad714x_chip *chip,
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unsigned short reg, unsigned short data)
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{
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struct spi_device *spi = to_spi_device(chip->dev);
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int error;
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chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX | reg);
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chip->xfer_buf[1] = cpu_to_be16(data);
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error = spi_write(spi, (u8 *)chip->xfer_buf,
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2 * sizeof(*chip->xfer_buf));
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if (unlikely(error)) {
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dev_err(chip->dev, "SPI write error: %d\n", error);
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return error;
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}
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return 0;
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}
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static int __devinit ad714x_spi_probe(struct spi_device *spi)
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{
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struct ad714x_chip *chip;
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int err;
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spi->bits_per_word = 8;
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err = spi_setup(spi);
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if (err < 0)
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return err;
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chip = ad714x_probe(&spi->dev, BUS_SPI, spi->irq,
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ad714x_spi_read, ad714x_spi_write);
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if (IS_ERR(chip))
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return PTR_ERR(chip);
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spi_set_drvdata(spi, chip);
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return 0;
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}
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static int __devexit ad714x_spi_remove(struct spi_device *spi)
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{
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struct ad714x_chip *chip = spi_get_drvdata(spi);
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ad714x_remove(chip);
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spi_set_drvdata(spi, NULL);
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return 0;
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}
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static struct spi_driver ad714x_spi_driver = {
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.driver = {
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.name = "ad714x_captouch",
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.owner = THIS_MODULE,
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.pm = &ad714x_spi_pm,
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},
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.probe = ad714x_spi_probe,
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.remove = __devexit_p(ad714x_spi_remove),
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};
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static __init int ad714x_spi_init(void)
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{
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return spi_register_driver(&ad714x_spi_driver);
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}
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module_init(ad714x_spi_init);
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static __exit void ad714x_spi_exit(void)
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{
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spi_unregister_driver(&ad714x_spi_driver);
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}
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module_exit(ad714x_spi_exit);
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MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor SPI Bus Driver");
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MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
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MODULE_LICENSE("GPL");
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