From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp2.megiteam.pl ([213.189.52.193]:49168 "EHLO smtp2.megiteam.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751317AbcKIOQp (ORCPT ); Wed, 9 Nov 2016 09:16:45 -0500 Subject: Re: [PATCH 1/2] iio: bmi160: Support hardware fifo To: Peter Meerwald-Stadler References: <20161103112527.29623-1-m.niestroj@grinn-global.com> Cc: Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Daniel Baluta , Gregor Boirie , Sanchayan Maity , Rob Herring , linux-iio@vger.kernel.org From: Marcin Niestroj Message-ID: Date: Wed, 9 Nov 2016 15:16:37 +0100 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org Hi, Thanks for review, below are my comments. On 03.11.2016 13:09, Peter Meerwald-Stadler wrote: > >> This patch was developed primarily based on bmc150_accel hardware fifo >> implementation. > > parts of the patch are cleanup and bugfixing; should be separate? > > more comments below > >> IRQ handler was added, which for now is responsible only for handling >> watermark interrupts. The BMI160 chip has two interrupt outputs. By >> default INT is considered to be connected. If INT2 is used instead, the >> interrupt-names device-tree property can be used to specify that. >> >> Signed-off-by: Marcin Niestroj >> --- >> drivers/iio/imu/bmi160/bmi160.h | 3 +- >> drivers/iio/imu/bmi160/bmi160_core.c | 633 +++++++++++++++++++++++++++++++++-- >> drivers/iio/imu/bmi160/bmi160_i2c.c | 7 +- >> drivers/iio/imu/bmi160/bmi160_spi.c | 3 +- >> 4 files changed, 618 insertions(+), 28 deletions(-) >> >> diff --git a/drivers/iio/imu/bmi160/bmi160.h b/drivers/iio/imu/bmi160/bmi160.h >> index d2ae6ed..4a7c10e 100644 >> --- a/drivers/iio/imu/bmi160/bmi160.h >> +++ b/drivers/iio/imu/bmi160/bmi160.h >> @@ -4,7 +4,8 @@ >> extern const struct regmap_config bmi160_regmap_config; >> >> int bmi160_core_probe(struct device *dev, struct regmap *regmap, >> - const char *name, bool use_spi); >> + const char *name, int irq, >> + bool use_spi, bool block_supported); >> void bmi160_core_remove(struct device *dev); >> >> #endif /* BMI160_H_ */ >> diff --git a/drivers/iio/imu/bmi160/bmi160_core.c b/drivers/iio/imu/bmi160/bmi160_core.c >> index e0251b8..153734c 100644 >> --- a/drivers/iio/imu/bmi160/bmi160_core.c >> +++ b/drivers/iio/imu/bmi160/bmi160_core.c >> @@ -2,6 +2,7 @@ >> * BMI160 - Bosch IMU (accel, gyro plus external magnetometer) >> * >> * Copyright (c) 2016, Intel Corporation. >> + * Copyright (c) 2016, Grinn >> * >> * This file is subject to the terms and conditions of version 2 of >> * the GNU General Public License. See the file COPYING in the main >> @@ -9,7 +10,7 @@ >> * >> * IIO core driver for BMI160, with support for I2C/SPI busses >> * >> - * TODO: magnetometer, interrupts, hardware FIFO >> + * TODO: magnetometer, interrupts >> */ >> #include >> #include >> @@ -22,8 +23,12 @@ >> #include >> #include >> >> +#include >> + >> #include "bmi160.h" >> >> +#define BMI160_IRQ_NAME "bmi160_event" >> + >> #define BMI160_REG_CHIP_ID 0x00 >> #define BMI160_CHIP_ID_VAL 0xD1 >> >> @@ -34,6 +39,21 @@ >> #define BMI160_REG_DATA_GYRO_XOUT_L 0x0C >> #define BMI160_REG_DATA_ACCEL_XOUT_L 0x12 >> >> +#define BMI160_REG_STATUS 0x1B >> +#define BMI160_STATUS_MAG_MAN_OP BIT(2) >> + >> +#define BMI160_REG_INT_STATUS0 0x1C >> + >> +#define BMI160_REG_INT_STATUS1 0x1D >> +#define BMI160_INT_STATUS_FWM BIT(6) >> + >> +#define BMI160_REG_INT_STATUS2 0x1E >> + >> +#define BMI160_REG_INT_STATUS3 0x1F >> + >> +#define BMI160_REG_FIFO_LENGTH 0x22 >> +#define BMI160_REG_FIFO_DATA 0x24 >> + >> #define BMI160_REG_ACCEL_CONFIG 0x40 >> #define BMI160_ACCEL_CONFIG_ODR_MASK GENMASK(3, 0) >> #define BMI160_ACCEL_CONFIG_BWP_MASK GENMASK(6, 4) >> @@ -55,6 +75,36 @@ >> #define BMI160_GYRO_RANGE_250DPS 0x03 >> #define BMI160_GYRO_RANGE_125DPS 0x04 >> >> +#define BMI160_REG_FIFO_CONFIG_0 0x46 >> + >> +#define BMI160_REG_FIFO_CONFIG_1 0x47 >> +#define BMI160_FIFO_GYRO_EN BIT(7) >> +#define BMI160_FIFO_ACCEL_EN BIT(6) >> +#define BMI160_FIFO_MAGN_EN BIT(5) >> +#define BMI160_FIFO_HEADER_EN BIT(4) >> +#define BMI160_FIFO_TAG_INT1_EN BIT(3) >> +#define BMI160_FIFO_TAG_INT2_EN BIT(2) >> +#define BMI160_FIFO_TIME_EN BIT(1) >> + >> +#define BMI160_REG_INT_EN_1 0x51 >> +#define BMI160_INT_FWM_EN BIT(6) >> +#define BMI160_INT_FFULL_EN BIT(5) >> +#define BMI160_INT_DRDY_EN BIT(4) >> + >> +#define BMI160_REG_INT_OUT_CTRL 0x53 >> +#define BMI160_INT2_OUTPUT_EN BIT(7) >> +#define BMI160_INT1_OUTPUT_EN BIT(3) >> + >> +#define BMI160_REG_INT_LATCH 0x54 >> + >> +#define BMI160_REG_INT_MAP_1 0x56 >> +#define BMI160_INT1_MAP_DRDY BIT(7) >> +#define BMI160_INT1_MAP_FWM BIT(6) >> +#define BMI160_INT1_MAP_FFULL BIT(5) >> +#define BMI160_INT2_MAP_DRDY BIT(3) >> +#define BMI160_INT2_MAP_FWM BIT(2) >> +#define BMI160_INT2_MAP_FFULL BIT(1) >> + >> #define BMI160_REG_CMD 0x7E >> #define BMI160_CMD_ACCEL_PM_SUSPEND 0x10 >> #define BMI160_CMD_ACCEL_PM_NORMAL 0x11 >> @@ -66,6 +116,8 @@ >> >> #define BMI160_REG_DUMMY 0x7F >> >> +#define BMI160_FIFO_LENGTH 1024 >> + >> #define BMI160_ACCEL_PMU_MIN_USLEEP 3200 >> #define BMI160_ACCEL_PMU_MAX_USLEEP 3800 >> #define BMI160_GYRO_PMU_MIN_USLEEP 55000 >> @@ -110,8 +162,33 @@ enum bmi160_sensor_type { >> BMI160_NUM_SENSORS /* must be last */ >> }; >> >> +struct bmi160_irq_data { >> + unsigned int map_fwm; >> + unsigned int output_en; >> +}; >> + >> +static const struct bmi160_irq_data bmi160_irq1_data = { >> + .map_fwm = BMI160_INT1_MAP_FWM, >> + .output_en = BMI160_INT1_OUTPUT_EN, >> +}; >> + >> +static const struct bmi160_irq_data bmi160_irq2_data = { >> + .map_fwm = BMI160_INT2_MAP_FWM, >> + .output_en = BMI160_INT2_OUTPUT_EN, >> +}; >> + >> struct bmi160_data { >> struct regmap *regmap; >> + struct mutex mutex; >> + const struct bmi160_irq_data *irq_data; >> + int irq; >> + int64_t timestamp; >> + int64_t fifo_sample_period; >> + bool fifo_enabled; >> + unsigned int fifo_config; >> + unsigned int fifo_sample_size; >> + u8 *fifo_buffer; >> + unsigned int watermark; >> }; >> >> const struct regmap_config bmi160_regmap_config = { >> @@ -159,11 +236,11 @@ struct bmi160_pmu_time { >> static struct bmi160_pmu_time bmi160_pmu_time[] = { >> [BMI160_ACCEL] = { >> .min = BMI160_ACCEL_PMU_MIN_USLEEP, >> - .max = BMI160_ACCEL_PMU_MAX_USLEEP >> + .max = BMI160_ACCEL_PMU_MAX_USLEEP, > > this is cosmetic cleanup > >> }, >> [BMI160_GYRO] = { >> .min = BMI160_GYRO_PMU_MIN_USLEEP, >> - .max = BMI160_GYRO_PMU_MIN_USLEEP, > > this looks like bug fixing I agree this should be a separate patch. I looked more deeply into the datasheet (2.11.38 Register 0x7E CMD). What we have specified in code as MIN value is in datasheet specified as typical time the command is executed. MAX value in the code corresponds to datasheet's maximum time the command takes place. According to that I think we should wait *at least* the maximum time specified in datasheet. Please correct me if I am wrong. > >> + .max = BMI160_GYRO_PMU_MAX_USLEEP, >> }, >> }; >> >> @@ -285,7 +362,9 @@ int bmi160_set_mode(struct bmi160_data *data, enum bmi160_sensor_type t, >> else >> cmd = bmi160_regs[t].pmu_cmd_suspend; >> >> + mutex_lock(&data->mutex); > > what does the mutex protect? > is it also needed without the fifo/irq support? > probably split out as a separate patch It protects data transmission on regmap_* functions. They are used from sysfs access functions as well as from bmi160_trigger_handler. I will create a separate bugfix patch for it. Additionally fifo_enabled and fifo_buffer are protected by mutex, after adding fifo support. > >> ret = regmap_write(data->regmap, BMI160_REG_CMD, cmd); >> + mutex_unlock(&data->mutex); >> if (ret < 0) >> return ret; >> >> @@ -298,6 +377,7 @@ static >> int bmi160_set_scale(struct bmi160_data *data, enum bmi160_sensor_type t, >> int uscale) >> { >> + int ret; >> int i; >> >> for (i = 0; i < bmi160_scale_table[t].num; i++) >> @@ -307,8 +387,12 @@ int bmi160_set_scale(struct bmi160_data *data, enum bmi160_sensor_type t, >> if (i == bmi160_scale_table[t].num) >> return -EINVAL; >> >> - return regmap_write(data->regmap, bmi160_regs[t].range, >> - bmi160_scale_table[t].tbl[i].bits); >> + mutex_lock(&data->mutex); >> + ret = regmap_write(data->regmap, bmi160_regs[t].range, >> + bmi160_scale_table[t].tbl[i].bits); >> + mutex_unlock(&data->mutex); >> + >> + return ret; >> } >> >> static >> @@ -317,7 +401,9 @@ int bmi160_get_scale(struct bmi160_data *data, enum bmi160_sensor_type t, >> { >> int i, ret, val; >> >> + mutex_lock(&data->mutex); >> ret = regmap_read(data->regmap, bmi160_regs[t].range, &val); >> + mutex_unlock(&data->mutex); >> if (ret < 0) >> return ret; >> >> @@ -340,7 +426,9 @@ static int bmi160_get_data(struct bmi160_data *data, int chan_type, >> >> reg = bmi160_regs[t].data + (axis - IIO_MOD_X) * sizeof(__le16); >> >> + mutex_lock(&data->mutex); >> ret = regmap_bulk_read(data->regmap, reg, &sample, sizeof(__le16)); >> + mutex_unlock(&data->mutex); >> if (ret < 0) >> return ret; >> >> @@ -353,6 +441,7 @@ static >> int bmi160_set_odr(struct bmi160_data *data, enum bmi160_sensor_type t, >> int odr, int uodr) >> { >> + int ret; >> int i; >> >> for (i = 0; i < bmi160_odr_table[t].num; i++) >> @@ -363,20 +452,30 @@ int bmi160_set_odr(struct bmi160_data *data, enum bmi160_sensor_type t, >> if (i >= bmi160_odr_table[t].num) >> return -EINVAL; >> >> - return regmap_update_bits(data->regmap, >> - bmi160_regs[t].config, >> - bmi160_regs[t].config_odr_mask, >> - bmi160_odr_table[t].tbl[i].bits); >> + mutex_lock(&data->mutex); >> + ret = regmap_update_bits(data->regmap, >> + bmi160_regs[t].config, >> + bmi160_regs[t].config_odr_mask, >> + bmi160_odr_table[t].tbl[i].bits); >> + mutex_unlock(&data->mutex); >> + >> + return ret; >> } >> >> -static int bmi160_get_odr(struct bmi160_data *data, enum bmi160_sensor_type t, >> - int *odr, int *uodr) >> +static int64_t bmi160_frequency_to_period(int odr, int uodr) >> { >> - int i, val, ret; >> + uint64_t period = 1000000000000000; >> + int64_t frequency = (int64_t) odr * 1000000 + uodr; >> >> - ret = regmap_read(data->regmap, bmi160_regs[t].config, &val); >> - if (ret < 0) >> - return ret; >> + do_div(period, frequency); >> + >> + return period; >> +} >> + >> +static const struct bmi160_odr *bmi160_reg_to_odr(enum bmi160_sensor_type t, >> + unsigned int val) >> +{ >> + int i; >> >> val &= bmi160_regs[t].config_odr_mask; >> >> @@ -385,10 +484,52 @@ static int bmi160_get_odr(struct bmi160_data *data, enum bmi160_sensor_type t, >> break; >> >> if (i >= bmi160_odr_table[t].num) >> - return -EINVAL; >> + return ERR_PTR(-EINVAL); >> + >> + return &bmi160_odr_table[t].tbl[i]; >> +} >> + >> +static int bmi160_get_sample_period(struct bmi160_data *data, >> + enum bmi160_sensor_type t, >> + int64_t *sample_period) >> +{ >> + const struct bmi160_odr *odr_entry; >> + int ret; >> + unsigned int val; >> + > > no mutex here? This function should be called when mutex is already acquired. Should be propably renamed to __bmi160_*. > >> + ret = regmap_read(data->regmap, bmi160_regs[t].config, &val); >> + if (ret < 0) >> + return ret; >> >> - *odr = bmi160_odr_table[t].tbl[i].odr; >> - *uodr = bmi160_odr_table[t].tbl[i].uodr; >> + odr_entry = bmi160_reg_to_odr(t, val); >> + if (IS_ERR(odr_entry)) >> + return PTR_ERR(odr_entry); >> + >> + *sample_period = bmi160_frequency_to_period(odr_entry->odr, >> + odr_entry->uodr); >> + >> + return 0; >> +} >> + >> +static int bmi160_get_odr(struct bmi160_data *data, enum bmi160_sensor_type t, >> + int *odr, int *uodr) >> +{ >> + const struct bmi160_odr *odr_entry; >> + int ret; >> + unsigned int val; >> + >> + mutex_lock(&data->mutex); >> + ret = regmap_read(data->regmap, bmi160_regs[t].config, &val); >> + mutex_unlock(&data->mutex); >> + if (ret < 0) >> + return ret; >> + >> + odr_entry = bmi160_reg_to_odr(t, val); >> + if (IS_ERR(odr_entry)) >> + return PTR_ERR(odr_entry); >> + >> + *odr = odr_entry->odr; >> + *uodr = odr_entry->uodr; >> >> return 0; >> } >> @@ -402,14 +543,18 @@ static irqreturn_t bmi160_trigger_handler(int irq, void *p) >> int i, ret, j = 0, base = BMI160_REG_DATA_MAGN_XOUT_L; >> __le16 sample; >> >> + mutex_lock(&data->mutex); >> for_each_set_bit(i, indio_dev->active_scan_mask, >> indio_dev->masklength) { >> ret = regmap_bulk_read(data->regmap, base + i * sizeof(__le16), >> &sample, sizeof(__le16)); >> - if (ret < 0) >> + if (ret < 0) { >> + mutex_unlock(&data->mutex); >> goto done; >> + } >> buf[j++] = sample; >> } >> + mutex_unlock(&data->mutex); >> >> iio_push_to_buffers_with_timestamp(indio_dev, buf, >> iio_get_time_ns(indio_dev)); >> @@ -493,11 +638,364 @@ static const struct attribute_group bmi160_attrs_group = { >> .attrs = bmi160_attrs, >> }; >> >> +static int bmi160_update_sample_period(struct bmi160_data *data, >> + enum bmi160_sensor_type sensor_type) >> +{ >> + struct device *dev = regmap_get_device(data->regmap); >> + int64_t sample_period; >> + int ret; >> + >> + ret = bmi160_get_sample_period(data, sensor_type, &sample_period); >> + if (ret < 0) >> + return ret; >> + >> + if (data->fifo_sample_period) { >> + if (data->fifo_sample_period != sample_period) { >> + dev_warn(dev, "Enabled sensors have unequal ODR values\n"); >> + return -EINVAL; >> + } >> + } else { >> + data->fifo_sample_period = sample_period; > > brackets not needed Sure. > >> + } >> + >> + return 0; >> +} >> + >> +static int bmi160_fifo_enable(struct iio_dev *indio_dev, >> + struct bmi160_data *data) >> +{ >> + struct regmap *regmap = data->regmap; >> + struct device *dev = regmap_get_device(regmap); >> + int ret; >> + int i; >> + unsigned int val; >> + unsigned int fifo_config = 0; >> + >> + /* Set fifo sample size and period */ >> + for_each_set_bit(i, indio_dev->active_scan_mask, >> + indio_dev->masklength) { >> + if (i <= BMI160_SCAN_GYRO_Z) >> + fifo_config |= BMI160_FIFO_GYRO_EN; >> + else if (i <= BMI160_SCAN_ACCEL_Z) >> + fifo_config |= BMI160_FIFO_ACCEL_EN; >> + } >> + >> + data->fifo_sample_period = 0; >> + data->fifo_sample_size = 0; >> + if (fifo_config & BMI160_FIFO_GYRO_EN) { >> + data->fifo_sample_size += 6; >> + ret = bmi160_update_sample_period(data, BMI160_GYRO); >> + if (ret < 0) >> + return ret; >> + } >> + if (fifo_config & BMI160_FIFO_ACCEL_EN) { >> + data->fifo_sample_size += 6; >> + ret = bmi160_update_sample_period(data, BMI160_ACCEL); >> + if (ret < 0) >> + return ret; >> + } >> + >> + /* >> + * Set watermark level and write real value back, as it will be used >> + * in timestamp calculation. >> + */ >> + val = data->watermark * data->fifo_sample_size; >> + if (val > BMI160_FIFO_LENGTH - 1) { >> + val = BMI160_FIFO_LENGTH - 1; >> + data->watermark = val / data->fifo_sample_size; >> + } >> + val = data->watermark * data->fifo_sample_size / 4; >> + >> + ret = regmap_write(regmap, BMI160_REG_FIFO_CONFIG_0, val); >> + if (ret < 0) { >> + dev_err(dev, "Failed to set watermark\n"); >> + return ret; >> + } >> + >> + /* Enable FIFO channels */ >> + ret = regmap_write(regmap, BMI160_REG_FIFO_CONFIG_1, >> + fifo_config); >> + if (ret < 0) { >> + dev_err(dev, "Failed to write FIFO_CONFIG_1\n"); >> + return ret; >> + } >> + >> + data->fifo_config = fifo_config; >> + data->fifo_enabled = true; >> + >> + return 0; >> +} >> + >> +static int bmi160_fifo_disable(struct bmi160_data *data) >> +{ >> + struct regmap *regmap = data->regmap; >> + struct device *dev = regmap_get_device(regmap); >> + int ret; >> + >> + /* Disable all FIFO channels */ >> + ret = regmap_write(regmap, BMI160_REG_FIFO_CONFIG_1, 0); >> + if (ret < 0) { >> + dev_err(dev, "Failed to write FIFO_CONFIG_1\n"); >> + return ret; >> + } >> + >> + data->fifo_enabled = false; >> + >> + return 0; >> +} >> + >> +static int bmi160_buffer_postenable(struct iio_dev *indio_dev) >> +{ >> + struct bmi160_data *data = iio_priv(indio_dev); >> + int ret; >> + >> + if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) >> + return iio_triggered_buffer_postenable(indio_dev); >> + >> + mutex_lock(&data->mutex); >> + ret = regmap_update_bits(data->regmap, BMI160_REG_INT_MAP_1, >> + data->irq_data->map_fwm, data->irq_data->map_fwm); >> + if (ret < 0) >> + goto unlock; >> + >> + ret = regmap_update_bits(data->regmap, BMI160_REG_INT_EN_1, >> + BMI160_INT_FWM_EN, BMI160_INT_FWM_EN); >> + if (ret < 0) >> + goto unlock; >> + >> + ret = bmi160_fifo_enable(indio_dev, data); >> + >> +unlock: >> + mutex_unlock(&data->mutex); >> + >> + return ret; >> +} >> + >> +static int bmi160_buffer_predisable(struct iio_dev *indio_dev) >> +{ >> + struct bmi160_data *data = iio_priv(indio_dev); >> + struct regmap *regmap = data->regmap; >> + int ret = 0; >> + >> + if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) >> + return iio_triggered_buffer_predisable(indio_dev); >> + >> + mutex_lock(&data->mutex); >> + >> + ret = regmap_update_bits(regmap, BMI160_REG_INT_EN_1, >> + BMI160_INT_FWM_EN, 0); >> + if (ret < 0) >> + goto unlock; >> + >> + ret = bmi160_fifo_disable(data); >> + >> +unlock: >> + mutex_unlock(&data->mutex); >> + >> + return ret; >> +} >> + >> +static const struct iio_buffer_setup_ops bmi160_buffer_ops = { >> + .postenable = bmi160_buffer_postenable, >> + .predisable = bmi160_buffer_predisable, >> +}; >> + >> +static ssize_t bmi160_get_fifo_state(struct device *dev, >> + struct device_attribute *attr, >> + char *buf) >> +{ >> + struct iio_dev *indio_dev = dev_to_iio_dev(dev); >> + struct bmi160_data *data = iio_priv(indio_dev); >> + bool state; >> + >> + mutex_lock(&data->mutex); >> + state = data->fifo_enabled; >> + mutex_unlock(&data->mutex); >> + >> + return sprintf(buf, "%d\n", (int) state); >> +} >> + >> +static ssize_t bmi160_get_fifo_watermark(struct device *dev, >> + struct device_attribute *attr, >> + char *buf) >> +{ >> + struct iio_dev *indio_dev = dev_to_iio_dev(dev); >> + struct bmi160_data *data = iio_priv(indio_dev); >> + int wm; >> + >> + mutex_lock(&data->mutex); >> + wm = data->watermark; >> + mutex_unlock(&data->mutex); >> + >> + return sprintf(buf, "%d\n", wm); >> +} >> + >> +static IIO_CONST_ATTR(hwfifo_watermark_min, "1"); >> +static IIO_CONST_ATTR(hwfifo_watermark_max, >> + __stringify(BMI160_FIFO_LENGTH)); >> +static IIO_DEVICE_ATTR(hwfifo_enabled, S_IRUGO, >> + bmi160_get_fifo_state, NULL, 0); >> +static IIO_DEVICE_ATTR(hwfifo_watermark, S_IRUGO, >> + bmi160_get_fifo_watermark, NULL, 0); >> + >> +static const struct attribute *bmi160_fifo_attributes[] = { >> + &iio_const_attr_hwfifo_watermark_min.dev_attr.attr, >> + &iio_const_attr_hwfifo_watermark_max.dev_attr.attr, >> + &iio_dev_attr_hwfifo_watermark.dev_attr.attr, >> + &iio_dev_attr_hwfifo_enabled.dev_attr.attr, >> + NULL, >> +}; >> + >> +static int bmi160_set_watermark(struct iio_dev *indio_dev, unsigned int val) >> +{ >> + struct bmi160_data *data = iio_priv(indio_dev); >> + >> + if (val > BMI160_FIFO_LENGTH) >> + val = BMI160_FIFO_LENGTH; >> + >> + data->watermark = val; >> + >> + return 0; >> +} >> + >> +static int bmi160_fifo_transfer(struct bmi160_data *data, >> + char *buffer, int num_bytes) >> +{ >> + struct regmap *regmap = data->regmap; >> + struct device *dev = regmap_get_device(regmap); >> + size_t step = regmap_get_raw_read_max(regmap); >> + int ret = 0; >> + int i; >> + >> + if (!step || step > num_bytes) >> + step = num_bytes; >> + else if (step < num_bytes) >> + step = data->fifo_sample_size; >> + >> + for (i = 0; i < num_bytes; i += step) { >> + ret = regmap_raw_read(regmap, BMI160_REG_FIFO_DATA, >> + &buffer[i], step); >> + >> + if (ret) >> + break; >> + } >> + >> + if (ret) >> + dev_err(dev, >> + "Error transferring data from fifo in single steps of %zu\n", >> + step); >> + >> + return ret; >> +} >> + >> +static int __bmi160_fifo_flush(struct iio_dev *indio_dev, >> + unsigned int samples, bool irq) > > what does the __ prefix denote? > likely that the function is supposed to be called with mutex held -- > maybe use that convention elsewhere as well? I will rename it together with other functions that assume mutex already acquired. > >> +{ >> + struct bmi160_data *data = iio_priv(indio_dev); >> + struct regmap *regmap = data->regmap; >> + struct device *dev = regmap_get_device(regmap); >> + int ret; >> + __le16 fifo_length; >> + unsigned int fifo_samples; >> + unsigned int fifo_bytes; >> + u8 *buffer = data->fifo_buffer; >> + u8 *buffer_iter; >> + int64_t last_timestamp, timestamp; >> + unsigned int last_samples; >> + unsigned int i; >> + >> + /* Get the current FIFO length */ >> + ret = regmap_bulk_read(regmap, BMI160_REG_FIFO_LENGTH, >> + &fifo_length, sizeof(__le16)); >> + if (ret < 0) { >> + dev_err(dev, "Error reading FIFO_LENGTH\n"); >> + return ret; >> + } >> + >> + fifo_bytes = le16_to_cpu(fifo_length); >> + fifo_samples = fifo_bytes / data->fifo_sample_size; >> + >> + if (fifo_bytes % data->fifo_sample_size) >> + dev_warn(dev, "fifo_bytes %u is not dividable by %u\n", >> + fifo_bytes, data->fifo_sample_size); >> + >> + if (!fifo_samples) >> + return 0; >> + >> + if (samples && fifo_samples > samples) { >> + fifo_samples = samples; >> + fifo_bytes = fifo_samples * data->fifo_sample_size; >> + } >> + >> + /* >> + * If we are not called from IRQ, it means that we are flushing data >> + * on demand. In that case we do not have latest timestamp saved in >> + * data->timestamp. Get the time now instead. >> + * >> + * In case of IRQ flush, saved timestamp shows the time when number >> + * of samples configured by watermark were ready. Currently there might >> + * be more samples already. >> + * If we are not called from IRQ, than we are getting the current fifo >> + * length, as we are setting timestamp just after getting it. >> + */ >> + if (!irq) { >> + last_timestamp = iio_get_time_ns(indio_dev); >> + last_samples = fifo_samples; >> + } else { >> + last_timestamp = data->timestamp; >> + last_samples = data->watermark; >> + } >> + >> + /* Get all measurements */ >> + ret = bmi160_fifo_transfer(data, buffer, fifo_bytes); >> + if (ret) >> + return ret; >> + >> + /* Handle demux */ >> + timestamp = last_timestamp - (last_samples * data->fifo_sample_period); >> + buffer_iter = buffer; >> + for (i = 0; i < fifo_samples; i++) { >> + u8 tmp_buf[indio_dev->scan_bytes]; > > non-constant array size, is this allowed these days? I am not sure if this is permitted in kernel. [1] says that ISO C99 adds arrays of variable length. The reason I have used it is that iio_push_to_buffers_with_timestamp uses indio_dev->scan_bytes to write timestamp to last element in array. One of the possiblities to get rid of non-constant array size is to determine maximum size. Is that what I should do? [1] https://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html > >> + >> + memcpy(tmp_buf, buffer_iter, data->fifo_sample_size); >> + >> + timestamp += data->fifo_sample_period; >> + iio_push_to_buffers_with_timestamp(indio_dev, >> + tmp_buf, >> + timestamp); >> + >> + buffer_iter += data->fifo_sample_size; >> + } >> + >> + return fifo_samples; >> +} >> + >> +static int bmi160_fifo_flush(struct iio_dev *indio_dev, unsigned int samples) >> +{ >> + struct bmi160_data *data = iio_priv(indio_dev); >> + int ret; >> + >> + mutex_lock(&data->mutex); >> + ret = __bmi160_fifo_flush(indio_dev, samples, false); >> + mutex_unlock(&data->mutex); >> + >> + return ret; >> +} >> + >> static const struct iio_info bmi160_info = { >> - .driver_module = THIS_MODULE, >> - .read_raw = bmi160_read_raw, >> - .write_raw = bmi160_write_raw, >> - .attrs = &bmi160_attrs_group, >> + .driver_module = THIS_MODULE, >> + .read_raw = bmi160_read_raw, >> + .write_raw = bmi160_write_raw, >> + .attrs = &bmi160_attrs_group, >> +}; >> + >> +static const struct iio_info bmi160_info_fifo = { >> + .driver_module = THIS_MODULE, >> + .read_raw = bmi160_read_raw, >> + .write_raw = bmi160_write_raw, >> + .attrs = &bmi160_attrs_group, >> + .hwfifo_set_watermark = bmi160_set_watermark, >> + .hwfifo_flush_to_buffer = bmi160_fifo_flush, >> }; >> >> static const char *bmi160_match_acpi_device(struct device *dev) >> @@ -561,12 +1059,54 @@ static void bmi160_chip_uninit(struct bmi160_data *data) >> bmi160_set_mode(data, BMI160_ACCEL, false); >> } >> >> +static int bmi160_enable_irq(struct bmi160_data *data) >> +{ >> + int ret; >> + >> + mutex_lock(&data->mutex); >> + ret = regmap_update_bits(data->regmap, BMI160_REG_INT_OUT_CTRL, >> + data->irq_data->output_en, >> + data->irq_data->output_en); >> + mutex_unlock(&data->mutex); >> + >> + return ret; >> +} >> + >> +static irqreturn_t bmi160_irq_thread_handler(int irq, void *p) >> +{ >> + struct iio_dev *indio_dev = p; >> + struct bmi160_data *data = iio_priv(indio_dev); >> + struct device *dev = regmap_get_device(data->regmap); >> + >> + mutex_lock(&data->mutex); >> + if (data->fifo_enabled) >> + __bmi160_fifo_flush(indio_dev, BMI160_FIFO_LENGTH, true); >> + else >> + dev_warn(dev, >> + "IRQ has been triggered, but FIFO is not enabled.\n"); >> + mutex_unlock(&data->mutex); >> + >> + return IRQ_HANDLED; >> +} >> + >> +static irqreturn_t bmi160_irq_handler(int irq, void *p) >> +{ >> + struct iio_dev *indio_dev = p; >> + struct bmi160_data *data = iio_priv(indio_dev); >> + >> + data->timestamp = iio_get_time_ns(indio_dev); >> + >> + return IRQ_WAKE_THREAD; >> +} >> + >> int bmi160_core_probe(struct device *dev, struct regmap *regmap, >> - const char *name, bool use_spi) >> + const char *name, int irq, >> + bool use_spi, bool block_supported) >> { >> struct iio_dev *indio_dev; >> struct bmi160_data *data; >> int ret; >> + int irq2; >> >> indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); >> if (!indio_dev) >> @@ -574,8 +1114,11 @@ int bmi160_core_probe(struct device *dev, struct regmap *regmap, >> >> data = iio_priv(indio_dev); >> dev_set_drvdata(dev, indio_dev); >> + data->irq = irq; >> data->regmap = regmap; >> >> + mutex_init(&data->mutex); >> + >> ret = bmi160_chip_init(data, use_spi); >> if (ret < 0) >> return ret; >> @@ -591,10 +1134,50 @@ int bmi160_core_probe(struct device *dev, struct regmap *regmap, >> indio_dev->info = &bmi160_info; >> >> ret = iio_triggered_buffer_setup(indio_dev, NULL, >> - bmi160_trigger_handler, NULL); >> + bmi160_trigger_handler, >> + &bmi160_buffer_ops); >> if (ret < 0) >> goto uninit; >> >> + if (data->irq > 0) { >> + /* Check which interrupt pin is connected to our board */ >> + irq2 = of_irq_get_byname(dev->of_node, "INT2"); >> + if (irq2 == data->irq) { >> + dev_dbg(dev, "Using interrupt line INT2\n"); >> + data->irq_data = &bmi160_irq2_data; >> + } else { >> + dev_dbg(dev, "Using interrupt line INT1\n"); >> + data->irq_data = &bmi160_irq1_data; >> + } >> + >> + ret = devm_request_threaded_irq(dev, >> + data->irq, >> + bmi160_irq_handler, >> + bmi160_irq_thread_handler, >> + IRQF_ONESHOT, >> + BMI160_IRQ_NAME, >> + indio_dev); >> + if (ret) >> + return ret; >> + >> + ret = bmi160_enable_irq(data); >> + if (ret < 0) >> + goto buffer_cleanup; >> + >> + if (block_supported) { >> + indio_dev->modes |= INDIO_BUFFER_SOFTWARE; >> + indio_dev->info = &bmi160_info_fifo; >> + indio_dev->buffer->attrs = bmi160_fifo_attributes; >> + data->fifo_buffer = devm_kmalloc(dev, >> + BMI160_FIFO_LENGTH, >> + GFP_KERNEL); >> + if (!data->fifo_buffer) { >> + ret = -ENOMEM; > > need to disable irq on failure? Yes, I missed that. > >> + goto buffer_cleanup; >> + } >> + } >> + } >> + >> ret = iio_device_register(indio_dev); >> if (ret < 0) >> goto buffer_cleanup; >> diff --git a/drivers/iio/imu/bmi160/bmi160_i2c.c b/drivers/iio/imu/bmi160/bmi160_i2c.c >> index 07a179d..aa63f89 100644 >> --- a/drivers/iio/imu/bmi160/bmi160_i2c.c >> +++ b/drivers/iio/imu/bmi160/bmi160_i2c.c >> @@ -23,6 +23,10 @@ static int bmi160_i2c_probe(struct i2c_client *client, >> { >> struct regmap *regmap; >> const char *name = NULL; >> + bool block_supported = >> + i2c_check_functionality(client->adapter, I2C_FUNC_I2C) || >> + i2c_check_functionality(client->adapter, >> + I2C_FUNC_SMBUS_READ_I2C_BLOCK); >> >> regmap = devm_regmap_init_i2c(client, &bmi160_regmap_config); >> if (IS_ERR(regmap)) { >> @@ -34,7 +38,8 @@ static int bmi160_i2c_probe(struct i2c_client *client, >> if (id) >> name = id->name; >> >> - return bmi160_core_probe(&client->dev, regmap, name, false); >> + return bmi160_core_probe(&client->dev, regmap, name, client->irq, >> + false, block_supported); >> } >> >> static int bmi160_i2c_remove(struct i2c_client *client) >> diff --git a/drivers/iio/imu/bmi160/bmi160_spi.c b/drivers/iio/imu/bmi160/bmi160_spi.c >> index 1ec8b12..9b57fbe 100644 >> --- a/drivers/iio/imu/bmi160/bmi160_spi.c >> +++ b/drivers/iio/imu/bmi160/bmi160_spi.c >> @@ -25,7 +25,8 @@ static int bmi160_spi_probe(struct spi_device *spi) >> (int)PTR_ERR(regmap)); >> return PTR_ERR(regmap); >> } >> - return bmi160_core_probe(&spi->dev, regmap, id->name, true); >> + return bmi160_core_probe(&spi->dev, regmap, id->name, spi->irq, >> + true, true); >> } >> >> static int bmi160_spi_remove(struct spi_device *spi) >> > -- Marcin Niestroj