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 <linux/iio/iio.h>
  16 #include <linux/iio/buffer.h>
  17 #include <linux/iio/kfifo_buf.h>
  18 #include <linux/iio/trigger_consumer.h>
  19 #include "ade7758.h"
  20
  21 /**
  22  * ade7758_spi_read_burst() - read data registers
  23  * @indio_dev: the IIO device
  24  **/
  25 static int ade7758_spi_read_burst(struct iio_dev *indio_dev)
  26 {
  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 int type)
  38 {
  39         int ret;
  40         u8 reg;
  41
  42         ret = ade7758_spi_read_reg_8(dev, ADE7758_WAVMODE, &reg);
  43         if (ret)
  44                 goto out;
  45
  46         reg &= ~0x1F;
  47         reg |= type & 0x1F;
  48
  49         ret = ade7758_spi_write_reg_8(dev, ADE7758_WAVMODE, reg);
  50 out:
  51         return ret;
  52 }
  53
  54 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is too device
  55  * specific to be rolled into the core.
  56  */
  57 static irqreturn_t ade7758_trigger_handler(int irq, void *p)
  58 {
  59         struct iio_poll_func *pf = p;
  60         struct iio_dev *indio_dev = pf->indio_dev;
  61         struct ade7758_state *st = iio_priv(indio_dev);
  62         s64 dat64[2];
  63         u32 *dat32 = (u32 *)dat64;
  64
  65         if (!bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
  66                 if (ade7758_spi_read_burst(indio_dev) >= 0)
  67                         *dat32 = get_unaligned_be32(&st->rx_buf[5]) & 0xFFFFFF;
  68
  69         iio_push_to_buffers_with_timestamp(indio_dev, dat64, pf->timestamp);
  70
  71         iio_trigger_notify_done(indio_dev->trig);
  72
  73         return IRQ_HANDLED;
  74 }
  75
  76 /**
  77  * ade7758_ring_preenable() setup the parameters of the ring before enabling
  78  *
  79  * The complex nature of the setting of the number of bytes per datum is due
  80  * to this driver currently ensuring that the timestamp is stored at an 8
  81  * byte boundary.
  82  **/
  83 static int ade7758_ring_preenable(struct iio_dev *indio_dev)
  84 {
  85         unsigned int channel;
  86
  87         if (bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
  88                 return -EINVAL;
  89
  90         channel = find_first_bit(indio_dev->active_scan_mask,
  91                                  indio_dev->masklength);
  92
  93         ade7758_write_waveform_type(&indio_dev->dev,
  94                                     indio_dev->channels[channel].address);
  95
  96         return 0;
  97 }
  98
  99 static const struct iio_buffer_setup_ops ade7758_ring_setup_ops = {
 100         .preenable = &ade7758_ring_preenable,
 101         .postenable = &iio_triggered_buffer_postenable,
 102         .predisable = &iio_triggered_buffer_predisable,
 103         .validate_scan_mask = &iio_validate_scan_mask_onehot,
 104 };
 105
 106 void ade7758_unconfigure_ring(struct iio_dev *indio_dev)
 107 {
 108         iio_dealloc_pollfunc(indio_dev->pollfunc);
 109         iio_kfifo_free(indio_dev->buffer);
 110 }
 111
 112 int ade7758_configure_ring(struct iio_dev *indio_dev)
 113 {
 114         struct ade7758_state *st = iio_priv(indio_dev);
 115         struct iio_buffer *buffer;
 116         int ret = 0;
 117
 118         buffer = iio_kfifo_allocate();
 119         if (!buffer)
 120                 return -ENOMEM;
 121
 122         iio_device_attach_buffer(indio_dev, buffer);
 123
 124         indio_dev->setup_ops = &ade7758_ring_setup_ops;
 125
 126         indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
 127                                                  &ade7758_trigger_handler,
 128                                                  0,
 129                                                  indio_dev,
 130                                                  "ade7759_consumer%d",
 131                                                  indio_dev->id);
 132         if (!indio_dev->pollfunc) {
 133                 ret = -ENOMEM;
 134                 goto error_iio_kfifo_free;
 135         }
 136
 137         indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
 138
 139         st->tx_buf[0] = ADE7758_READ_REG(ADE7758_RSTATUS);
 140         st->tx_buf[1] = 0;
 141         st->tx_buf[2] = 0;
 142         st->tx_buf[3] = 0;
 143         st->tx_buf[4] = ADE7758_READ_REG(ADE7758_WFORM);
 144         st->tx_buf[5] = 0;
 145         st->tx_buf[6] = 0;
 146         st->tx_buf[7] = 0;
 147
 148         /* build spi ring message */
 149         st->ring_xfer[0].tx_buf = &st->tx_buf[0];
 150         st->ring_xfer[0].len = 1;
 151         st->ring_xfer[0].bits_per_word = 8;
 152         st->ring_xfer[0].delay_usecs = 4;
 153         st->ring_xfer[1].rx_buf = &st->rx_buf[1];
 154         st->ring_xfer[1].len = 3;
 155         st->ring_xfer[1].bits_per_word = 8;
 156         st->ring_xfer[1].cs_change = 1;
 157
 158         st->ring_xfer[2].tx_buf = &st->tx_buf[4];
 159         st->ring_xfer[2].len = 1;
 160         st->ring_xfer[2].bits_per_word = 8;
 161         st->ring_xfer[2].delay_usecs = 1;
 162         st->ring_xfer[3].rx_buf = &st->rx_buf[5];
 163         st->ring_xfer[3].len = 3;
 164         st->ring_xfer[3].bits_per_word = 8;
 165
 166         spi_message_init(&st->ring_msg);
 167         spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
 168         spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
 169         spi_message_add_tail(&st->ring_xfer[2], &st->ring_msg);
 170         spi_message_add_tail(&st->ring_xfer[3], &st->ring_msg);
 171
 172         return 0;
 173
 174 error_iio_kfifo_free:
 175         iio_kfifo_free(indio_dev->buffer);
 176         return ret;
 177 }