1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Common library for ADIS16XXX devices 4 * 5 * Copyright 2012 Analog Devices Inc. 6 * Author: Lars-Peter Clausen <lars@metafoo.de> 7 */ 8 9 #include <linux/export.h> 10 #include <linux/interrupt.h> 11 #include <linux/mutex.h> 12 #include <linux/kernel.h> 13 #include <linux/spi/spi.h> 14 #include <linux/slab.h> 15 16 #include <linux/iio/iio.h> 17 #include <linux/iio/buffer.h> 18 #include <linux/iio/trigger_consumer.h> 19 #include <linux/iio/triggered_buffer.h> 20 #include <linux/iio/imu/adis.h> 21 22 static int adis_update_scan_mode_burst(struct iio_dev *indio_dev, 23 const unsigned long *scan_mask) 24 { 25 struct adis *adis = iio_device_get_drvdata(indio_dev); 26 unsigned int burst_length; 27 u8 *tx; 28 29 /* All but the timestamp channel */ 30 burst_length = (indio_dev->num_channels - 1) * sizeof(u16); 31 burst_length += adis->burst->extra_len; 32 33 adis->xfer = kcalloc(2, sizeof(*adis->xfer), GFP_KERNEL); 34 if (!adis->xfer) 35 return -ENOMEM; 36 37 adis->buffer = kzalloc(burst_length + sizeof(u16), GFP_KERNEL); 38 if (!adis->buffer) 39 return -ENOMEM; 40 41 tx = adis->buffer + burst_length; 42 tx[0] = ADIS_READ_REG(adis->burst->reg_cmd); 43 tx[1] = 0; 44 45 adis->xfer[0].tx_buf = tx; 46 adis->xfer[0].bits_per_word = 8; 47 adis->xfer[0].len = 2; 48 adis->xfer[1].rx_buf = adis->buffer; 49 adis->xfer[1].bits_per_word = 8; 50 adis->xfer[1].len = burst_length; 51 52 spi_message_init(&adis->msg); 53 spi_message_add_tail(&adis->xfer[0], &adis->msg); 54 spi_message_add_tail(&adis->xfer[1], &adis->msg); 55 56 return 0; 57 } 58 59 int adis_update_scan_mode(struct iio_dev *indio_dev, 60 const unsigned long *scan_mask) 61 { 62 struct adis *adis = iio_device_get_drvdata(indio_dev); 63 const struct iio_chan_spec *chan; 64 unsigned int scan_count; 65 unsigned int i, j; 66 __be16 *tx, *rx; 67 68 kfree(adis->xfer); 69 kfree(adis->buffer); 70 71 if (adis->burst && adis->burst->en) 72 return adis_update_scan_mode_burst(indio_dev, scan_mask); 73 74 scan_count = indio_dev->scan_bytes / 2; 75 76 adis->xfer = kcalloc(scan_count + 1, sizeof(*adis->xfer), GFP_KERNEL); 77 if (!adis->xfer) 78 return -ENOMEM; 79 80 adis->buffer = kcalloc(indio_dev->scan_bytes, 2, GFP_KERNEL); 81 if (!adis->buffer) 82 return -ENOMEM; 83 84 rx = adis->buffer; 85 tx = rx + scan_count; 86 87 spi_message_init(&adis->msg); 88 89 for (j = 0; j <= scan_count; j++) { 90 adis->xfer[j].bits_per_word = 8; 91 if (j != scan_count) 92 adis->xfer[j].cs_change = 1; 93 adis->xfer[j].len = 2; 94 adis->xfer[j].delay_usecs = adis->data->read_delay; 95 if (j < scan_count) 96 adis->xfer[j].tx_buf = &tx[j]; 97 if (j >= 1) 98 adis->xfer[j].rx_buf = &rx[j - 1]; 99 spi_message_add_tail(&adis->xfer[j], &adis->msg); 100 } 101 102 chan = indio_dev->channels; 103 for (i = 0; i < indio_dev->num_channels; i++, chan++) { 104 if (!test_bit(chan->scan_index, scan_mask)) 105 continue; 106 if (chan->scan_type.storagebits == 32) 107 *tx++ = cpu_to_be16((chan->address + 2) << 8); 108 *tx++ = cpu_to_be16(chan->address << 8); 109 } 110 111 return 0; 112 } 113 EXPORT_SYMBOL_GPL(adis_update_scan_mode); 114 115 static irqreturn_t adis_trigger_handler(int irq, void *p) 116 { 117 struct iio_poll_func *pf = p; 118 struct iio_dev *indio_dev = pf->indio_dev; 119 struct adis *adis = iio_device_get_drvdata(indio_dev); 120 int ret; 121 122 if (!adis->buffer) 123 return -ENOMEM; 124 125 if (adis->data->has_paging) { 126 mutex_lock(&adis->txrx_lock); 127 if (adis->current_page != 0) { 128 adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID); 129 adis->tx[1] = 0; 130 spi_write(adis->spi, adis->tx, 2); 131 } 132 } 133 134 ret = spi_sync(adis->spi, &adis->msg); 135 if (ret) 136 dev_err(&adis->spi->dev, "Failed to read data: %d", ret); 137 138 139 if (adis->data->has_paging) { 140 adis->current_page = 0; 141 mutex_unlock(&adis->txrx_lock); 142 } 143 144 iio_push_to_buffers_with_timestamp(indio_dev, adis->buffer, 145 pf->timestamp); 146 147 iio_trigger_notify_done(indio_dev->trig); 148 149 return IRQ_HANDLED; 150 } 151 152 /** 153 * adis_setup_buffer_and_trigger() - Sets up buffer and trigger for the adis device 154 * @adis: The adis device. 155 * @indio_dev: The IIO device. 156 * @trigger_handler: Optional trigger handler, may be NULL. 157 * 158 * Returns 0 on success, a negative error code otherwise. 159 * 160 * This function sets up the buffer and trigger for a adis devices. If 161 * 'trigger_handler' is NULL the default trigger handler will be used. The 162 * default trigger handler will simply read the registers assigned to the 163 * currently active channels. 164 * 165 * adis_cleanup_buffer_and_trigger() should be called to free the resources 166 * allocated by this function. 167 */ 168 int adis_setup_buffer_and_trigger(struct adis *adis, struct iio_dev *indio_dev, 169 irqreturn_t (*trigger_handler)(int, void *)) 170 { 171 int ret; 172 173 if (!trigger_handler) 174 trigger_handler = adis_trigger_handler; 175 176 ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, 177 trigger_handler, NULL); 178 if (ret) 179 return ret; 180 181 if (adis->spi->irq) { 182 ret = adis_probe_trigger(adis, indio_dev); 183 if (ret) 184 goto error_buffer_cleanup; 185 } 186 return 0; 187 188 error_buffer_cleanup: 189 iio_triggered_buffer_cleanup(indio_dev); 190 return ret; 191 } 192 EXPORT_SYMBOL_GPL(adis_setup_buffer_and_trigger); 193 194 /** 195 * adis_cleanup_buffer_and_trigger() - Free buffer and trigger resources 196 * @adis: The adis device. 197 * @indio_dev: The IIO device. 198 * 199 * Frees resources allocated by adis_setup_buffer_and_trigger() 200 */ 201 void adis_cleanup_buffer_and_trigger(struct adis *adis, 202 struct iio_dev *indio_dev) 203 { 204 if (adis->spi->irq) 205 adis_remove_trigger(adis); 206 kfree(adis->buffer); 207 kfree(adis->xfer); 208 iio_triggered_buffer_cleanup(indio_dev); 209 } 210 EXPORT_SYMBOL_GPL(adis_cleanup_buffer_and_trigger); 211