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 /* 50 * Ensure correct alignment and padding including for the 51 * timestamp that may be inserted. 52 */ 53 struct { 54 __be16 buf[ITG3200_SCAN_ELEMENTS]; 55 s64 ts __aligned(8); 56 } scan; 57 58 int ret = itg3200_read_all_channels(st->i2c, scan.buf); 59 if (ret < 0) 60 goto error_ret; 61 62 iio_push_to_buffers_with_timestamp(indio_dev, &scan, pf->timestamp); 63 64 error_ret: 65 iio_trigger_notify_done(indio_dev->trig); 66 67 return IRQ_HANDLED; 68 } 69 70 int itg3200_buffer_configure(struct iio_dev *indio_dev) 71 { 72 return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, 73 itg3200_trigger_handler, NULL); 74 } 75 76 void itg3200_buffer_unconfigure(struct iio_dev *indio_dev) 77 { 78 iio_triggered_buffer_cleanup(indio_dev); 79 } 80 81 82 static int itg3200_data_rdy_trigger_set_state(struct iio_trigger *trig, 83 bool state) 84 { 85 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); 86 int ret; 87 u8 msc; 88 89 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, &msc); 90 if (ret) 91 goto error_ret; 92 93 if (state) 94 msc |= ITG3200_IRQ_DATA_RDY_ENABLE; 95 else 96 msc &= ~ITG3200_IRQ_DATA_RDY_ENABLE; 97 98 ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, msc); 99 if (ret) 100 goto error_ret; 101 102 error_ret: 103 return ret; 104 105 } 106 107 static const struct iio_trigger_ops itg3200_trigger_ops = { 108 .set_trigger_state = &itg3200_data_rdy_trigger_set_state, 109 }; 110 111 int itg3200_probe_trigger(struct iio_dev *indio_dev) 112 { 113 int ret; 114 struct itg3200 *st = iio_priv(indio_dev); 115 116 st->trig = iio_trigger_alloc(&st->i2c->dev, "%s-dev%d", indio_dev->name, 117 iio_device_id(indio_dev)); 118 if (!st->trig) 119 return -ENOMEM; 120 121 ret = request_irq(st->i2c->irq, 122 &iio_trigger_generic_data_rdy_poll, 123 IRQF_TRIGGER_RISING, 124 "itg3200_data_rdy", 125 st->trig); 126 if (ret) 127 goto error_free_trig; 128 129 130 st->trig->ops = &itg3200_trigger_ops; 131 iio_trigger_set_drvdata(st->trig, indio_dev); 132 ret = iio_trigger_register(st->trig); 133 if (ret) 134 goto error_free_irq; 135 136 /* select default trigger */ 137 indio_dev->trig = iio_trigger_get(st->trig); 138 139 return 0; 140 141 error_free_irq: 142 free_irq(st->i2c->irq, st->trig); 143 error_free_trig: 144 iio_trigger_free(st->trig); 145 return ret; 146 } 147 148 void itg3200_remove_trigger(struct iio_dev *indio_dev) 149 { 150 struct itg3200 *st = iio_priv(indio_dev); 151 152 iio_trigger_unregister(st->trig); 153 free_irq(st->i2c->irq, st->trig); 154 iio_trigger_free(st->trig); 155 } 156