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/kfifo_buf.h>
  17 #include <linux/iio/trigger_consumer.h>
  18 #include "ade7758.h"
  19
  20 /**
  21  * ade7758_spi_read_burst() - read data registers
  22  * @indio_dev: the IIO device
  23  **/
  24 static int ade7758_spi_read_burst(struct iio_dev *indio_dev)
  25 {
  26         struct ade7758_state *st = iio_priv(indio_dev);
  27         int ret;
  28
  29         ret = spi_sync(st->us, &st->ring_msg);
  30         if (ret)
  31                 dev_err(&st->us->dev, "problem when reading WFORM value\n");
  32
  33         return ret;
  34 }
  35
  36 static int ade7758_write_waveform_type(struct device *dev, unsigned int type)
  37 {
  38         int ret;
  39         u8 reg;
  40
  41         ret = ade7758_spi_read_reg_8(dev, ADE7758_WAVMODE, &reg);
  42         if (ret)
  43                 goto out;
  44
  45         reg &= ~0x1F;
  46         reg |= type & 0x1F;
  47
  48         ret = ade7758_spi_write_reg_8(dev, ADE7758_WAVMODE, reg);
  49 out:
  50         return ret;
  51 }
  52
  53 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is too device
  54  * specific to be rolled into the core.
  55  */
  56 static irqreturn_t ade7758_trigger_handler(int irq, void *p)
  57 {
  58         struct iio_poll_func *pf = p;
  59         struct iio_dev *indio_dev = pf->indio_dev;
  60         struct ade7758_state *st = iio_priv(indio_dev);
  61         s64 dat64[2];
  62         u32 *dat32 = (u32 *)dat64;
  63
  64         if (!bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
  65                 if (ade7758_spi_read_burst(indio_dev) >= 0)
  66                         *dat32 = get_unaligned_be32(&st->rx_buf[5]) & 0xFFFFFF;
  67
  68         iio_push_to_buffers_with_timestamp(indio_dev, dat64, pf->timestamp);
  69
  70         iio_trigger_notify_done(indio_dev->trig);
  71
  72         return IRQ_HANDLED;
  73 }
  74
  75 /**
  76  * ade7758_ring_preenable() setup the parameters of the ring before enabling
  77  *
  78  * The complex nature of the setting of the number of bytes per datum is due
  79  * to this driver currently ensuring that the timestamp is stored at an 8
  80  * byte boundary.
  81  **/
  82 static int ade7758_ring_preenable(struct iio_dev *indio_dev)
  83 {
  84         unsigned int channel;
  85
  86         if (bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
  87                 return -EINVAL;
  88
  89         channel = find_first_bit(indio_dev->active_scan_mask,
  90                                  indio_dev->masklength);
  91
  92         ade7758_write_waveform_type(&indio_dev->dev,
  93                                     indio_dev->channels[channel].address);
  94
  95         return 0;
  96 }
  97
  98 static const struct iio_buffer_setup_ops ade7758_ring_setup_ops = {
  99         .preenable = &ade7758_ring_preenable,
 100         .postenable = &iio_triggered_buffer_postenable,
 101         .predisable = &iio_triggered_buffer_predisable,
 102         .validate_scan_mask = &iio_validate_scan_mask_onehot,
 103 };
 104
 105 void ade7758_unconfigure_ring(struct iio_dev *indio_dev)
 106 {
 107         iio_dealloc_pollfunc(indio_dev->pollfunc);
 108         iio_kfifo_free(indio_dev->buffer);
 109 }
 110
 111 int ade7758_configure_ring(struct iio_dev *indio_dev)
 112 {
 113         struct ade7758_state *st = iio_priv(indio_dev);
 114         struct iio_buffer *buffer;
 115         int ret = 0;
 116
 117         buffer = iio_kfifo_allocate();
 118         if (!buffer)
 119                 return -ENOMEM;
 120
 121         iio_device_attach_buffer(indio_dev, buffer);
 122
 123         indio_dev->setup_ops = &ade7758_ring_setup_ops;
 124
 125         indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
 126                                                  &ade7758_trigger_handler,
 127                                                  0,
 128                                                  indio_dev,
 129                                                  "ade7759_consumer%d",
 130                                                  indio_dev->id);
 131         if (!indio_dev->pollfunc) {
 132                 ret = -ENOMEM;
 133                 goto error_iio_kfifo_free;
 134         }
 135
 136         indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
 137
 138         st->tx_buf[0] = ADE7758_READ_REG(ADE7758_RSTATUS);
 139         st->tx_buf[1] = 0;
 140         st->tx_buf[2] = 0;
 141         st->tx_buf[3] = 0;
 142         st->tx_buf[4] = ADE7758_READ_REG(ADE7758_WFORM);
 143         st->tx_buf[5] = 0;
 144         st->tx_buf[6] = 0;
 145         st->tx_buf[7] = 0;
 146
 147         /* build spi ring message */
 148         st->ring_xfer[0].tx_buf = &st->tx_buf[0];
 149         st->ring_xfer[0].len = 1;
 150         st->ring_xfer[0].bits_per_word = 8;
 151         st->ring_xfer[0].delay_usecs = 4;
 152         st->ring_xfer[1].rx_buf = &st->rx_buf[1];
 153         st->ring_xfer[1].len = 3;
 154         st->ring_xfer[1].bits_per_word = 8;
 155         st->ring_xfer[1].cs_change = 1;
 156
 157         st->ring_xfer[2].tx_buf = &st->tx_buf[4];
 158         st->ring_xfer[2].len = 1;
 159         st->ring_xfer[2].bits_per_word = 8;
 160         st->ring_xfer[2].delay_usecs = 1;
 161         st->ring_xfer[3].rx_buf = &st->rx_buf[5];
 162         st->ring_xfer[3].len = 3;
 163         st->ring_xfer[3].bits_per_word = 8;
 164
 165         spi_message_init(&st->ring_msg);
 166         spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
 167         spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
 168         spi_message_add_tail(&st->ring_xfer[2], &st->ring_msg);
 169         spi_message_add_tail(&st->ring_xfer[3], &st->ring_msg);
 170
 171         return 0;
 172
 173 error_iio_kfifo_free:
 174         iio_kfifo_free(indio_dev->buffer);
 175         return ret;
 176 }