/* * kxsd9.c simple support for the Kionix KXSD9 3D * accelerometer. * * Copyright (c) 2008-2009 Jonathan Cameron * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * The i2c interface is very similar, so shouldn't be a problem once * I have a suitable wire made up. * * TODO: Support the motion detector * Uses register address incrementing so could have a * heavily optimized ring buffer access function. */ #include #include #include #include #include #include #include #include #define KXSD9_REG_X 0x00 #define KXSD9_REG_Y 0x02 #define KXSD9_REG_Z 0x04 #define KXSD9_REG_AUX 0x06 #define KXSD9_REG_RESET 0x0a #define KXSD9_REG_CTRL_C 0x0c #define KXSD9_FS_MASK 0x03 #define KXSD9_REG_CTRL_B 0x0d #define KXSD9_REG_CTRL_A 0x0e #define KXSD9_READ(a) (0x80 | (a)) #define KXSD9_WRITE(a) (a) #define KXSD9_STATE_RX_SIZE 2 #define KXSD9_STATE_TX_SIZE 2 /** * struct kxsd9_state - device related storage * @buf_lock: protect the rx and tx buffers. * @us: spi device * @rx: single rx buffer storage * @tx: single tx buffer storage **/ struct kxsd9_state { struct mutex buf_lock; struct spi_device *us; u8 rx[KXSD9_STATE_RX_SIZE] ____cacheline_aligned; u8 tx[KXSD9_STATE_TX_SIZE]; }; #define KXSD9_SCALE_2G "0.011978" #define KXSD9_SCALE_4G "0.023927" #define KXSD9_SCALE_6G "0.035934" #define KXSD9_SCALE_8G "0.047853" /* reverse order */ static const int kxsd9_micro_scales[4] = { 47853, 35934, 23927, 11978 }; static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro) { int ret, i; struct kxsd9_state *st = iio_priv(indio_dev); bool foundit = false; for (i = 0; i < 4; i++) if (micro == kxsd9_micro_scales[i]) { foundit = true; break; } if (!foundit) return -EINVAL; mutex_lock(&st->buf_lock); ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C)); if (ret) goto error_ret; st->tx[0] = KXSD9_WRITE(KXSD9_REG_CTRL_C); st->tx[1] = (ret & ~KXSD9_FS_MASK) | i; ret = spi_write(st->us, st->tx, 2); error_ret: mutex_unlock(&st->buf_lock); return ret; } static int kxsd9_read(struct iio_dev *indio_dev, u8 address) { int ret; struct kxsd9_state *st = iio_priv(indio_dev); struct spi_transfer xfers[] = { { .bits_per_word = 8, .len = 1, .delay_usecs = 200, .tx_buf = st->tx, }, { .bits_per_word = 8, .len = 2, .rx_buf = st->rx, }, }; mutex_lock(&st->buf_lock); st->tx[0] = KXSD9_READ(address); ret = spi_sync_transfer(st->us, xfers, ARRAY_SIZE(xfers)); if (ret) return ret; return (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0); } static IIO_CONST_ATTR(accel_scale_available, KXSD9_SCALE_2G " " KXSD9_SCALE_4G " " KXSD9_SCALE_6G " " KXSD9_SCALE_8G); static struct attribute *kxsd9_attributes[] = { &iio_const_attr_accel_scale_available.dev_attr.attr, NULL, }; static int kxsd9_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { int ret = -EINVAL; if (mask == IIO_CHAN_INFO_SCALE) { /* Check no integer component */ if (val) return -EINVAL; ret = kxsd9_write_scale(indio_dev, val2); } return ret; } static int kxsd9_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { int ret = -EINVAL; struct kxsd9_state *st = iio_priv(indio_dev); switch (mask) { case IIO_CHAN_INFO_RAW: ret = kxsd9_read(indio_dev, chan->address); if (ret < 0) goto error_ret; *val = ret; break; case IIO_CHAN_INFO_SCALE: ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C)); if (ret) goto error_ret; *val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK]; ret = IIO_VAL_INT_PLUS_MICRO; break; } error_ret: return ret; }; #define KXSD9_ACCEL_CHAN(axis) \ { \ .type = IIO_ACCEL, \ .modified = 1, \ .channel2 = IIO_MOD_##axis, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ .address = KXSD9_REG_##axis, \ } static const struct iio_chan_spec kxsd9_channels[] = { KXSD9_ACCEL_CHAN(X), KXSD9_ACCEL_CHAN(Y), KXSD9_ACCEL_CHAN(Z), { .type = IIO_VOLTAGE, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .indexed = 1, .address = KXSD9_REG_AUX, } }; static const struct attribute_group kxsd9_attribute_group = { .attrs = kxsd9_attributes, }; static int kxsd9_power_up(struct kxsd9_state *st) { int ret; st->tx[0] = 0x0d; st->tx[1] = 0x40; ret = spi_write(st->us, st->tx, 2); if (ret) return ret; st->tx[0] = 0x0c; st->tx[1] = 0x9b; return spi_write(st->us, st->tx, 2); }; static const struct iio_info kxsd9_info = { .read_raw = &kxsd9_read_raw, .write_raw = &kxsd9_write_raw, .attrs = &kxsd9_attribute_group, .driver_module = THIS_MODULE, }; static int kxsd9_probe(struct spi_device *spi) { struct iio_dev *indio_dev; struct kxsd9_state *st; int ret; indio_dev = iio_device_alloc(sizeof(*st)); if (indio_dev == NULL) { ret = -ENOMEM; goto error_ret; } st = iio_priv(indio_dev); spi_set_drvdata(spi, indio_dev); st->us = spi; mutex_init(&st->buf_lock); indio_dev->channels = kxsd9_channels; indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels); indio_dev->name = spi_get_device_id(spi)->name; indio_dev->dev.parent = &spi->dev; indio_dev->info = &kxsd9_info; indio_dev->modes = INDIO_DIRECT_MODE; spi->mode = SPI_MODE_0; spi_setup(spi); kxsd9_power_up(st); ret = iio_device_register(indio_dev); if (ret) goto error_free_dev; return 0; error_free_dev: iio_device_free(indio_dev); error_ret: return ret; } static int kxsd9_remove(struct spi_device *spi) { iio_device_unregister(spi_get_drvdata(spi)); iio_device_free(spi_get_drvdata(spi)); return 0; } static const struct spi_device_id kxsd9_id[] = { {"kxsd9", 0}, { }, }; MODULE_DEVICE_TABLE(spi, kxsd9_id); static struct spi_driver kxsd9_driver = { .driver = { .name = "kxsd9", .owner = THIS_MODULE, }, .probe = kxsd9_probe, .remove = kxsd9_remove, .id_table = kxsd9_id, }; module_spi_driver(kxsd9_driver); MODULE_AUTHOR("Jonathan Cameron "); MODULE_DESCRIPTION("Kionix KXSD9 SPI driver"); MODULE_LICENSE("GPL v2");