The L3GD0 is an on-board peripheral of the STM32F429-DISCOVERY and as such a good target to test out SPI driver support. Add a simple aiodev driver to interface with it. It can read the chip's angular rate in three dimensions as well as the temperature sensor embedded in it.
Signed-off-by: Ahmad Fatoum <[email protected]> --- drivers/aiodev/Kconfig | 6 ++ drivers/aiodev/Makefile | 1 + drivers/aiodev/st_gyro.c | 122 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 129 insertions(+) create mode 100644 drivers/aiodev/st_gyro.c diff --git a/drivers/aiodev/Kconfig b/drivers/aiodev/Kconfig index 88a3b9a3431c..6bd697702ecf 100644 --- a/drivers/aiodev/Kconfig +++ b/drivers/aiodev/Kconfig @@ -30,6 +30,12 @@ config LM75 help Support for LM75 and similar devices +config ST_GYRO + tristate "ST L3GD20 SPI gyro driver" + depends on SPI + help + Support for L3GD20 three-axis angular rate sensor. + config MC13XXX_ADC tristate "MC13XXX ADC driver" depends on MFD_MC13XXX diff --git a/drivers/aiodev/Makefile b/drivers/aiodev/Makefile index 4c92a403a293..06a63b0d2d78 100644 --- a/drivers/aiodev/Makefile +++ b/drivers/aiodev/Makefile @@ -3,6 +3,7 @@ obj-$(CONFIG_AIODEV) += core.o obj-$(CONFIG_IMX_THERMAL) += imx_thermal.o obj-$(CONFIG_LM75) += lm75.o +obj-$(CONFIG_ST_GYRO) += st_gyro.o obj-$(CONFIG_MC13XXX_ADC) += mc13xxx_adc.o obj-$(CONFIG_QORIQ_THERMAL) += qoriq_thermal.o obj-$(CONFIG_AM335X_ADC) += am335x_adc.o diff --git a/drivers/aiodev/st_gyro.c b/drivers/aiodev/st_gyro.c new file mode 100644 index 000000000000..3938d8239e4b --- /dev/null +++ b/drivers/aiodev/st_gyro.c @@ -0,0 +1,122 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +// SPDX-FileCopyrightText: 2022 Ahmad Fatoum + +#include <common.h> +#include <driver.h> +#include <xfuncs.h> +#include <spi/spi.h> +#include <aiodev.h> + +#define ST_GYRO_WHO_AM_I 0x0F +#define ST_GYRO_CTRL_REG1 0x20 + +#define ST_GYRO_DEFAULT_OUT_TEMP_ADDR 0x26 +#define ST_GYRO_DEFAULT_OUT_X_L_ADDR 0x28 +#define ST_GYRO_DEFAULT_OUT_Y_L_ADDR 0x2a +#define ST_GYRO_DEFAULT_OUT_Z_L_ADDR 0x2c + +#define ST_GYRO_OUT_L_ADDR(idx) \ + (ST_GYRO_DEFAULT_OUT_X_L_ADDR + 2 * (idx)) + +#define ST_GYRO_OUT_H_ADDR(idx) \ + (ST_GYRO_OUT_L_ADDR(idx) + 1) + +#define ST_GYRO_READ 0x80 +#define ST_GYRO_WRITE 0x00 +#define ST_GYRO_MULTI 0x40 + +struct st_gyro { + struct aiodevice aiodev; + struct aiochannel aiochan[4]; + struct spi_device *spi; +}; +#define to_st_gyro(chan) container_of(chan->aiodev, struct st_gyro, aiodev) + +static int st_gyro_read(struct aiochannel *chan, int *val) +{ + struct st_gyro *gyro = to_st_gyro(chan); + int ret; + u8 tx; + u8 rx_h, rx_l; + + if (chan->index == 3) { + tx = ST_GYRO_DEFAULT_OUT_TEMP_ADDR | ST_GYRO_READ; + ret = spi_write_then_read(gyro->spi, &tx, 1, &rx_l, 1); + if (ret) + return ret; + + *val = (s8)rx_l; + return 0; + } + + tx = ST_GYRO_OUT_H_ADDR(chan->index) | ST_GYRO_READ; + ret = spi_write_then_read(gyro->spi, &tx, 1, &rx_h, 1); + if (ret) + return ret; + + tx = ST_GYRO_OUT_L_ADDR(chan->index) | ST_GYRO_READ; + ret = spi_write_then_read(gyro->spi, &tx, 1, &rx_l, 1); + if (ret) + return ret; + + *val = (s16)((rx_h << 8) | rx_l); + *val *= 250; + *val >>= 16; + + return 0; +} + +static int st_gyro_probe(struct device_d *dev) +{ + u8 tx[2], rx[2]; + struct st_gyro *gyro; + int ret, i; + + gyro = xzalloc(sizeof(*gyro)); + gyro->spi = to_spi_device(dev); + + tx[0] = ST_GYRO_WHO_AM_I | ST_GYRO_READ; + ret = spi_write_then_read(gyro->spi, tx, 1, rx, 1); + if (ret) + return -EIO; + if (rx[0] != 0xD4) + return dev_err_probe(dev, -ENODEV, "unexpected device WAI: %02x\n", rx[0]); + + /* initialize device */ + tx[0] = ST_GYRO_CTRL_REG1 | ST_GYRO_WRITE; + tx[1] = 0xF; /* normal mode, 3 channels */ + ret = spi_write(gyro->spi, tx, 2); + if (ret) + return -EIO; + + gyro->aiodev.num_channels = 4; + gyro->aiodev.hwdev = dev; + gyro->aiodev.read = st_gyro_read; + gyro->aiodev.name = "gyroscope"; + gyro->aiodev.channels = + xmalloc(gyro->aiodev.num_channels * + sizeof(gyro->aiodev.channels[0])); + for (i = 0; i < 3; i++) { + gyro->aiodev.channels[i] = &gyro->aiochan[i]; + gyro->aiochan[i].unit = "dps"; + gyro->aiochan[i].index = i; + } + + gyro->aiodev.channels[3] = &gyro->aiochan[3]; + gyro->aiochan[3].unit = "C"; + gyro->aiochan[3].index = 3; + + return aiodevice_register(&gyro->aiodev); +} + +static const struct of_device_id st_gyro_match[] = { + { .compatible = "st,l3gd20-gyro" }, + { /* sentinel */ } +}; + +static struct driver_d st_gyro_driver = { + .name = "st_gyro", + .probe = st_gyro_probe, + .of_compatible = st_gyro_match, +}; +device_spi_driver(st_gyro_driver); -- 2.34.1
