1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * itg3200_buffer.c -- support InvenSense ITG3200 4 * Digital 3-Axis Gyroscope driver 5 * 6 * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de> 7 * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de> 8 * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de> 9 */ 10 11 #include <linux/slab.h> 12 #include <linux/i2c.h> 13 #include <linux/interrupt.h> 14 15 #include <linux/iio/iio.h> 16 #include <linux/iio/buffer.h> 17 #include <linux/iio/trigger.h> 18 #include <linux/iio/trigger_consumer.h> 19 #include <linux/iio/triggered_buffer.h> 20 #include <linux/iio/gyro/itg3200.h> 21 22 23 static int itg3200_read_all_channels(struct i2c_client *i2c, __be16 *buf) 24 { 25 u8 tx = 0x80 | ITG3200_REG_TEMP_OUT_H; 26 struct i2c_msg msg[2] = { 27 { 28 .addr = i2c->addr, 29 .flags = i2c->flags, 30 .len = 1, 31 .buf = &tx, 32 }, 33 { 34 .addr = i2c->addr, 35 .flags = i2c->flags | I2C_M_RD, 36 .len = ITG3200_SCAN_ELEMENTS * sizeof(s16), 37 .buf = (char *)&buf, 38 }, 39 }; 40 41 return i2c_transfer(i2c->adapter, msg, 2); 42 } 43 44 static irqreturn_t itg3200_trigger_handler(int irq, void *p) 45 { 46 struct iio_poll_func *pf = p; 47 struct iio_dev *indio_dev = pf->indio_dev; 48 struct itg3200 *st = iio_priv(indio_dev); 49 __be16 buf[ITG3200_SCAN_ELEMENTS + sizeof(s64)/sizeof(u16)]; 50 51 int ret = itg3200_read_all_channels(st->i2c, buf); 52 if (ret < 0) 53 goto error_ret; 54 55 iio_push_to_buffers_with_timestamp(indio_dev, buf, pf->timestamp); 56 57 iio_trigger_notify_done(indio_dev->trig); 58 59 error_ret: 60 return IRQ_HANDLED; 61 } 62 63 int itg3200_buffer_configure(struct iio_dev *indio_dev) 64 { 65 return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, 66 itg3200_trigger_handler, NULL); 67 } 68 69 void itg3200_buffer_unconfigure(struct iio_dev *indio_dev) 70 { 71 iio_triggered_buffer_cleanup(indio_dev); 72 } 73 74 75 static int itg3200_data_rdy_trigger_set_state(struct iio_trigger *trig, 76 bool state) 77 { 78 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); 79 int ret; 80 u8 msc; 81 82 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, &msc); 83 if (ret) 84 goto error_ret; 85 86 if (state) 87 msc |= ITG3200_IRQ_DATA_RDY_ENABLE; 88 else 89 msc &= ~ITG3200_IRQ_DATA_RDY_ENABLE; 90 91 ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, msc); 92 if (ret) 93 goto error_ret; 94 95 error_ret: 96 return ret; 97 98 } 99 100 static const struct iio_trigger_ops itg3200_trigger_ops = { 101 .set_trigger_state = &itg3200_data_rdy_trigger_set_state, 102 }; 103 104 int itg3200_probe_trigger(struct iio_dev *indio_dev) 105 { 106 int ret; 107 struct itg3200 *st = iio_priv(indio_dev); 108 109 st->trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, 110 indio_dev->id); 111 if (!st->trig) 112 return -ENOMEM; 113 114 ret = request_irq(st->i2c->irq, 115 &iio_trigger_generic_data_rdy_poll, 116 IRQF_TRIGGER_RISING, 117 "itg3200_data_rdy", 118 st->trig); 119 if (ret) 120 goto error_free_trig; 121 122 123 st->trig->dev.parent = &st->i2c->dev; 124 st->trig->ops = &itg3200_trigger_ops; 125 iio_trigger_set_drvdata(st->trig, indio_dev); 126 ret = iio_trigger_register(st->trig); 127 if (ret) 128 goto error_free_irq; 129 130 /* select default trigger */ 131 indio_dev->trig = iio_trigger_get(st->trig); 132 133 return 0; 134 135 error_free_irq: 136 free_irq(st->i2c->irq, st->trig); 137 error_free_trig: 138 iio_trigger_free(st->trig); 139 return ret; 140 } 141 142 void itg3200_remove_trigger(struct iio_dev *indio_dev) 143 { 144 struct itg3200 *st = iio_priv(indio_dev); 145 146 iio_trigger_unregister(st->trig); 147 free_irq(st->i2c->irq, st->trig); 148 iio_trigger_free(st->trig); 149 } 150