Ge Gao | 09a642b | 2013-02-02 00:26:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 Invensense, Inc. |
| 3 | * |
| 4 | * This software is licensed under the terms of the GNU General Public |
| 5 | * License version 2, as published by the Free Software Foundation, and |
| 6 | * may be copied, distributed, and modified under those terms. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/module.h> |
Ge Gao | 09a642b | 2013-02-02 00:26:00 +0000 | [diff] [blame] | 15 | #include <linux/slab.h> |
| 16 | #include <linux/i2c.h> |
| 17 | #include <linux/err.h> |
| 18 | #include <linux/delay.h> |
| 19 | #include <linux/sysfs.h> |
| 20 | #include <linux/jiffies.h> |
| 21 | #include <linux/irq.h> |
| 22 | #include <linux/interrupt.h> |
| 23 | #include <linux/kfifo.h> |
| 24 | #include <linux/poll.h> |
| 25 | #include "inv_mpu_iio.h" |
| 26 | |
| 27 | int inv_reset_fifo(struct iio_dev *indio_dev) |
| 28 | { |
| 29 | int result; |
| 30 | u8 d; |
| 31 | struct inv_mpu6050_state *st = iio_priv(indio_dev); |
| 32 | |
| 33 | /* disable interrupt */ |
| 34 | result = inv_mpu6050_write_reg(st, st->reg->int_enable, 0); |
| 35 | if (result) { |
| 36 | dev_err(&st->client->dev, "int_enable failed %d\n", result); |
| 37 | return result; |
| 38 | } |
| 39 | /* disable the sensor output to FIFO */ |
| 40 | result = inv_mpu6050_write_reg(st, st->reg->fifo_en, 0); |
| 41 | if (result) |
| 42 | goto reset_fifo_fail; |
| 43 | /* disable fifo reading */ |
| 44 | result = inv_mpu6050_write_reg(st, st->reg->user_ctrl, 0); |
| 45 | if (result) |
| 46 | goto reset_fifo_fail; |
| 47 | |
| 48 | /* reset FIFO*/ |
| 49 | result = inv_mpu6050_write_reg(st, st->reg->user_ctrl, |
| 50 | INV_MPU6050_BIT_FIFO_RST); |
| 51 | if (result) |
| 52 | goto reset_fifo_fail; |
| 53 | /* enable interrupt */ |
| 54 | if (st->chip_config.accl_fifo_enable || |
| 55 | st->chip_config.gyro_fifo_enable) { |
| 56 | result = inv_mpu6050_write_reg(st, st->reg->int_enable, |
| 57 | INV_MPU6050_BIT_DATA_RDY_EN); |
| 58 | if (result) |
| 59 | return result; |
| 60 | } |
| 61 | /* enable FIFO reading and I2C master interface*/ |
| 62 | result = inv_mpu6050_write_reg(st, st->reg->user_ctrl, |
| 63 | INV_MPU6050_BIT_FIFO_EN); |
| 64 | if (result) |
| 65 | goto reset_fifo_fail; |
| 66 | /* enable sensor output to FIFO */ |
| 67 | d = 0; |
| 68 | if (st->chip_config.gyro_fifo_enable) |
| 69 | d |= INV_MPU6050_BITS_GYRO_OUT; |
| 70 | if (st->chip_config.accl_fifo_enable) |
| 71 | d |= INV_MPU6050_BIT_ACCEL_OUT; |
| 72 | result = inv_mpu6050_write_reg(st, st->reg->fifo_en, d); |
| 73 | if (result) |
| 74 | goto reset_fifo_fail; |
| 75 | |
| 76 | return 0; |
| 77 | |
| 78 | reset_fifo_fail: |
| 79 | dev_err(&st->client->dev, "reset fifo failed %d\n", result); |
| 80 | result = inv_mpu6050_write_reg(st, st->reg->int_enable, |
| 81 | INV_MPU6050_BIT_DATA_RDY_EN); |
| 82 | |
| 83 | return result; |
| 84 | } |
| 85 | |
| 86 | static void inv_clear_kfifo(struct inv_mpu6050_state *st) |
| 87 | { |
| 88 | unsigned long flags; |
| 89 | |
| 90 | /* take the spin lock sem to avoid interrupt kick in */ |
| 91 | spin_lock_irqsave(&st->time_stamp_lock, flags); |
| 92 | kfifo_reset(&st->timestamps); |
| 93 | spin_unlock_irqrestore(&st->time_stamp_lock, flags); |
| 94 | } |
| 95 | |
| 96 | /** |
| 97 | * inv_mpu6050_irq_handler() - Cache a timestamp at each data ready interrupt. |
| 98 | */ |
| 99 | irqreturn_t inv_mpu6050_irq_handler(int irq, void *p) |
| 100 | { |
| 101 | struct iio_poll_func *pf = p; |
| 102 | struct iio_dev *indio_dev = pf->indio_dev; |
| 103 | struct inv_mpu6050_state *st = iio_priv(indio_dev); |
| 104 | s64 timestamp; |
| 105 | |
| 106 | timestamp = iio_get_time_ns(); |
Ge Gao | 6c23811 | 2013-03-04 23:27:00 +0000 | [diff] [blame] | 107 | kfifo_in_spinlocked(&st->timestamps, ×tamp, 1, |
| 108 | &st->time_stamp_lock); |
Ge Gao | 09a642b | 2013-02-02 00:26:00 +0000 | [diff] [blame] | 109 | |
| 110 | return IRQ_WAKE_THREAD; |
| 111 | } |
| 112 | |
| 113 | /** |
| 114 | * inv_mpu6050_read_fifo() - Transfer data from hardware FIFO to KFIFO. |
| 115 | */ |
| 116 | irqreturn_t inv_mpu6050_read_fifo(int irq, void *p) |
| 117 | { |
| 118 | struct iio_poll_func *pf = p; |
| 119 | struct iio_dev *indio_dev = pf->indio_dev; |
| 120 | struct inv_mpu6050_state *st = iio_priv(indio_dev); |
| 121 | size_t bytes_per_datum; |
| 122 | int result; |
| 123 | u8 data[INV_MPU6050_OUTPUT_DATA_SIZE]; |
| 124 | u16 fifo_count; |
| 125 | s64 timestamp; |
Ge Gao | 09a642b | 2013-02-02 00:26:00 +0000 | [diff] [blame] | 126 | |
| 127 | mutex_lock(&indio_dev->mlock); |
| 128 | if (!(st->chip_config.accl_fifo_enable | |
| 129 | st->chip_config.gyro_fifo_enable)) |
| 130 | goto end_session; |
| 131 | bytes_per_datum = 0; |
| 132 | if (st->chip_config.accl_fifo_enable) |
| 133 | bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR; |
| 134 | |
| 135 | if (st->chip_config.gyro_fifo_enable) |
| 136 | bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR; |
| 137 | |
| 138 | /* |
| 139 | * read fifo_count register to know how many bytes inside FIFO |
| 140 | * right now |
| 141 | */ |
| 142 | result = i2c_smbus_read_i2c_block_data(st->client, |
| 143 | st->reg->fifo_count_h, |
| 144 | INV_MPU6050_FIFO_COUNT_BYTE, data); |
| 145 | if (result != INV_MPU6050_FIFO_COUNT_BYTE) |
| 146 | goto end_session; |
| 147 | fifo_count = be16_to_cpup((__be16 *)(&data[0])); |
| 148 | if (fifo_count < bytes_per_datum) |
| 149 | goto end_session; |
| 150 | /* fifo count can't be odd number, if it is odd, reset fifo*/ |
| 151 | if (fifo_count & 1) |
| 152 | goto flush_fifo; |
| 153 | if (fifo_count > INV_MPU6050_FIFO_THRESHOLD) |
| 154 | goto flush_fifo; |
| 155 | /* Timestamp mismatch. */ |
| 156 | if (kfifo_len(&st->timestamps) > |
| 157 | fifo_count / bytes_per_datum + INV_MPU6050_TIME_STAMP_TOR) |
| 158 | goto flush_fifo; |
| 159 | while (fifo_count >= bytes_per_datum) { |
| 160 | result = i2c_smbus_read_i2c_block_data(st->client, |
| 161 | st->reg->fifo_r_w, |
| 162 | bytes_per_datum, data); |
| 163 | if (result != bytes_per_datum) |
| 164 | goto flush_fifo; |
| 165 | |
| 166 | result = kfifo_out(&st->timestamps, ×tamp, 1); |
| 167 | /* when there is no timestamp, put timestamp as 0 */ |
| 168 | if (0 == result) |
| 169 | timestamp = 0; |
| 170 | |
Lars-Peter Clausen | 01901d4 | 2013-09-19 13:59:00 +0100 | [diff] [blame] | 171 | result = iio_push_to_buffers_with_timestamp(indio_dev, data, |
| 172 | timestamp); |
Ge Gao | 09a642b | 2013-02-02 00:26:00 +0000 | [diff] [blame] | 173 | if (result) |
| 174 | goto flush_fifo; |
| 175 | fifo_count -= bytes_per_datum; |
| 176 | } |
| 177 | |
| 178 | end_session: |
| 179 | mutex_unlock(&indio_dev->mlock); |
| 180 | iio_trigger_notify_done(indio_dev->trig); |
| 181 | |
| 182 | return IRQ_HANDLED; |
| 183 | |
| 184 | flush_fifo: |
| 185 | /* Flush HW and SW FIFOs. */ |
| 186 | inv_reset_fifo(indio_dev); |
| 187 | inv_clear_kfifo(st); |
| 188 | mutex_unlock(&indio_dev->mlock); |
| 189 | iio_trigger_notify_done(indio_dev->trig); |
| 190 | |
| 191 | return IRQ_HANDLED; |
| 192 | } |