1 /* 2 * itg3200_buffer.c -- support InvenSense ITG3200 3 * Digital 3-Axis Gyroscope driver 4 * 5 * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de> 6 * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de> 7 * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #include <linux/slab.h> 15 #include <linux/i2c.h> 16 #include <linux/interrupt.h> 17 18 #include <linux/iio/iio.h> 19 #include <linux/iio/buffer.h> 20 #include <linux/iio/trigger.h> 21 #include <linux/iio/trigger_consumer.h> 22 #include <linux/iio/triggered_buffer.h> 23 #include <linux/iio/gyro/itg3200.h> 24 25 26 static int itg3200_read_all_channels(struct i2c_client *i2c, __be16 *buf) 27 { 28 u8 tx = 0x80 | ITG3200_REG_TEMP_OUT_H; 29 struct i2c_msg msg[2] = { 30 { 31 .addr = i2c->addr, 32 .flags = i2c->flags, 33 .len = 1, 34 .buf = &tx, 35 }, 36 { 37 .addr = i2c->addr, 38 .flags = i2c->flags | I2C_M_RD, 39 .len = ITG3200_SCAN_ELEMENTS * sizeof(s16), 40 .buf = (char *)&buf, 41 }, 42 }; 43 44 return i2c_transfer(i2c->adapter, msg, 2); 45 } 46 47 static irqreturn_t itg3200_trigger_handler(int irq, void *p) 48 { 49 struct iio_poll_func *pf = p; 50 struct iio_dev *indio_dev = pf->indio_dev; 51 struct itg3200 *st = iio_priv(indio_dev); 52 __be16 buf[ITG3200_SCAN_ELEMENTS + sizeof(s64)/sizeof(u16)]; 53 54 int ret = itg3200_read_all_channels(st->i2c, buf); 55 if (ret < 0) 56 goto error_ret; 57 58 iio_push_to_buffers_with_timestamp(indio_dev, buf, pf->timestamp); 59 60 iio_trigger_notify_done(indio_dev->trig); 61 62 error_ret: 63 return IRQ_HANDLED; 64 } 65 66 int itg3200_buffer_configure(struct iio_dev *indio_dev) 67 { 68 return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, 69 itg3200_trigger_handler, NULL); 70 } 71 72 void itg3200_buffer_unconfigure(struct iio_dev *indio_dev) 73 { 74 iio_triggered_buffer_cleanup(indio_dev); 75 } 76 77 78 static int itg3200_data_rdy_trigger_set_state(struct iio_trigger *trig, 79 bool state) 80 { 81 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); 82 int ret; 83 u8 msc; 84 85 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, &msc); 86 if (ret) 87 goto error_ret; 88 89 if (state) 90 msc |= ITG3200_IRQ_DATA_RDY_ENABLE; 91 else 92 msc &= ~ITG3200_IRQ_DATA_RDY_ENABLE; 93 94 ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, msc); 95 if (ret) 96 goto error_ret; 97 98 error_ret: 99 return ret; 100 101 } 102 103 static const struct iio_trigger_ops itg3200_trigger_ops = { 104 .owner = THIS_MODULE, 105 .set_trigger_state = &itg3200_data_rdy_trigger_set_state, 106 }; 107 108 int itg3200_probe_trigger(struct iio_dev *indio_dev) 109 { 110 int ret; 111 struct itg3200 *st = iio_priv(indio_dev); 112 113 st->trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, 114 indio_dev->id); 115 if (!st->trig) 116 return -ENOMEM; 117 118 ret = request_irq(st->i2c->irq, 119 &iio_trigger_generic_data_rdy_poll, 120 IRQF_TRIGGER_RISING, 121 "itg3200_data_rdy", 122 st->trig); 123 if (ret) 124 goto error_free_trig; 125 126 127 st->trig->dev.parent = &st->i2c->dev; 128 st->trig->ops = &itg3200_trigger_ops; 129 iio_trigger_set_drvdata(st->trig, indio_dev); 130 ret = iio_trigger_register(st->trig); 131 if (ret) 132 goto error_free_irq; 133 134 /* select default trigger */ 135 indio_dev->trig = iio_trigger_get(st->trig); 136 137 return 0; 138 139 error_free_irq: 140 free_irq(st->i2c->irq, st->trig); 141 error_free_trig: 142 iio_trigger_free(st->trig); 143 return ret; 144 } 145 146 void itg3200_remove_trigger(struct iio_dev *indio_dev) 147 { 148 struct itg3200 *st = iio_priv(indio_dev); 149 150 iio_trigger_unregister(st->trig); 151 free_irq(st->i2c->irq, st->trig); 152 iio_trigger_free(st->trig); 153 } 154