drivers/staging/iio/meter/ade7758_ring.c

   1 /*
   2  * ADE7758 Poly Phase Multifunction Energy Metering IC driver
   3  *
   4  * Copyright 2010-2011 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2.
   7  */
   8 #include <linux/export.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/kernel.h>
  11 #include <linux/spi/spi.h>
  12 #include <linux/slab.h>
  13 #include <asm/unaligned.h>
  14
  15 #include "../iio.h"
  16 #include "../ring_sw.h"
  17 #include "../trigger_consumer.h"
  18 #include "ade7758.h"
  19
  20 /**
  21  * ade7758_spi_read_burst() - read data registers
  22  * @dev: device associated with child of actual device (iio_dev or iio_trig)
  23  **/
  24 static int ade7758_spi_read_burst(struct device *dev)
  25 {
  26         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  27         struct ade7758_state *st = iio_priv(indio_dev);
  28         int ret;
  29
  30         ret = spi_sync(st->us, &st->ring_msg);
  31         if (ret)
  32                 dev_err(&st->us->dev, "problem when reading WFORM value\n");
  33
  34         return ret;
  35 }
  36
  37 static int ade7758_write_waveform_type(struct device *dev, unsigned type)
  38 {
  39         int ret;
  40         u8 reg;
  41
  42         ret = ade7758_spi_read_reg_8(dev,
  43                         ADE7758_WAVMODE,
  44                         &reg);
  45         if (ret)
  46                 goto out;
  47
  48         reg &= ~0x1F;
  49         reg |= type & 0x1F;
  50
  51         ret = ade7758_spi_write_reg_8(dev,
  52                         ADE7758_WAVMODE,
  53                         reg);
  54 out:
  55         return ret;
  56 }
  57
  58 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
  59  * specific to be rolled into the core.
  60  */
  61 static irqreturn_t ade7758_trigger_handler(int irq, void *p)
  62 {
  63         struct iio_poll_func *pf = p;
  64         struct iio_dev *indio_dev = pf->indio_dev;
  65         struct iio_buffer *ring = indio_dev->buffer;
  66         struct ade7758_state *st = iio_priv(indio_dev);
  67         s64 dat64[2];
  68         u32 *dat32 = (u32 *)dat64;
  69
  70         if (ring->scan_count)
  71                 if (ade7758_spi_read_burst(&indio_dev->dev) >= 0)
  72                         *dat32 = get_unaligned_be32(&st->rx_buf[5]) & 0xFFFFFF;
  73
  74         /* Guaranteed to be aligned with 8 byte boundary */
  75         if (ring->scan_timestamp)
  76                 dat64[1] = pf->timestamp;
  77
  78         ring->access->store_to(ring, (u8 *)dat64, pf->timestamp);
  79
  80         iio_trigger_notify_done(indio_dev->trig);
  81
  82         return IRQ_HANDLED;
  83 }
  84
  85 /**
  86  * ade7758_ring_preenable() setup the parameters of the ring before enabling
  87  *
  88  * The complex nature of the setting of the nuber of bytes per datum is due
  89  * to this driver currently ensuring that the timestamp is stored at an 8
  90  * byte boundary.
  91  **/
  92 static int ade7758_ring_preenable(struct iio_dev *indio_dev)
  93 {
  94         struct ade7758_state *st = iio_priv(indio_dev);
  95         struct iio_buffer *ring = indio_dev->buffer;
  96         size_t d_size;
  97         unsigned channel;
  98
  99         if (!ring->scan_count)
 100                 return -EINVAL;
 101
 102         channel = find_first_bit(ring->scan_mask, indio_dev->masklength);
 103
 104         d_size = st->ade7758_ring_channels[channel].scan_type.storagebits / 8;
 105
 106         if (ring->scan_timestamp) {
 107                 d_size += sizeof(s64);
 108
 109                 if (d_size % sizeof(s64))
 110                         d_size += sizeof(s64) - (d_size % sizeof(s64));
 111         }
 112
 113         if (indio_dev->buffer->access->set_bytes_per_datum)
 114                 indio_dev->buffer->access->
 115                         set_bytes_per_datum(indio_dev->buffer, d_size);
 116
 117         ade7758_write_waveform_type(&indio_dev->dev,
 118                 st->ade7758_ring_channels[channel].address);
 119
 120         return 0;
 121 }
 122
 123 static const struct iio_buffer_setup_ops ade7758_ring_setup_ops = {
 124         .preenable = &ade7758_ring_preenable,
 125         .postenable = &iio_triggered_buffer_postenable,
 126         .predisable = &iio_triggered_buffer_predisable,
 127 };
 128
 129 void ade7758_unconfigure_ring(struct iio_dev *indio_dev)
 130 {
 131         iio_dealloc_pollfunc(indio_dev->pollfunc);
 132         iio_sw_rb_free(indio_dev->buffer);
 133 }
 134
 135 int ade7758_configure_ring(struct iio_dev *indio_dev)
 136 {
 137         struct ade7758_state *st = iio_priv(indio_dev);
 138         int ret = 0;
 139
 140         indio_dev->buffer = iio_sw_rb_allocate(indio_dev);
 141         if (!indio_dev->buffer) {
 142                 ret = -ENOMEM;
 143                 return ret;
 144         }
 145
 146         /* Effectively select the ring buffer implementation */
 147         indio_dev->buffer->access = &ring_sw_access_funcs;
 148         indio_dev->buffer->setup_ops = &ade7758_ring_setup_ops;
 149         indio_dev->buffer->owner = THIS_MODULE;
 150
 151         indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
 152                                                  &ade7758_trigger_handler,
 153                                                  0,
 154                                                  indio_dev,
 155                                                  "ade7759_consumer%d",
 156                                                  indio_dev->id);
 157         if (indio_dev->pollfunc == NULL) {
 158                 ret = -ENOMEM;
 159                 goto error_iio_sw_rb_free;
 160         }
 161
 162         indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
 163
 164         st->tx_buf[0] = ADE7758_READ_REG(ADE7758_RSTATUS);
 165         st->tx_buf[1] = 0;
 166         st->tx_buf[2] = 0;
 167         st->tx_buf[3] = 0;
 168         st->tx_buf[4] = ADE7758_READ_REG(ADE7758_WFORM);
 169         st->tx_buf[5] = 0;
 170         st->tx_buf[6] = 0;
 171         st->tx_buf[7] = 0;
 172
 173         /* build spi ring message */
 174         st->ring_xfer[0].tx_buf = &st->tx_buf[0];
 175         st->ring_xfer[0].len = 1;
 176         st->ring_xfer[0].bits_per_word = 8;
 177         st->ring_xfer[0].delay_usecs = 4;
 178         st->ring_xfer[1].rx_buf = &st->rx_buf[1];
 179         st->ring_xfer[1].len = 3;
 180         st->ring_xfer[1].bits_per_word = 8;
 181         st->ring_xfer[1].cs_change = 1;
 182
 183         st->ring_xfer[2].tx_buf = &st->tx_buf[4];
 184         st->ring_xfer[2].len = 1;
 185         st->ring_xfer[2].bits_per_word = 8;
 186         st->ring_xfer[2].delay_usecs = 1;
 187         st->ring_xfer[3].rx_buf = &st->rx_buf[5];
 188         st->ring_xfer[3].len = 3;
 189         st->ring_xfer[3].bits_per_word = 8;
 190
 191         spi_message_init(&st->ring_msg);
 192         spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
 193         spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
 194         spi_message_add_tail(&st->ring_xfer[2], &st->ring_msg);
 195         spi_message_add_tail(&st->ring_xfer[3], &st->ring_msg);
 196
 197         return 0;
 198
 199 error_iio_sw_rb_free:
 200         iio_sw_rb_free(indio_dev->buffer);
 201         return ret;
 202 }
 203
 204 void ade7758_uninitialize_ring(struct iio_dev *indio_dev)
 205 {
 206         iio_buffer_unregister(indio_dev);
 207 }