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 type)
  37 {
  38         int ret;
  39         u8 reg;
  40
  41         ret = ade7758_spi_read_reg_8(dev,
  42                         ADE7758_WAVMODE,
  43                         &reg);
  44         if (ret)
  45                 goto out;
  46
  47         reg &= ~0x1F;
  48         reg |= type & 0x1F;
  49
  50         ret = ade7758_spi_write_reg_8(dev,
  51                         ADE7758_WAVMODE,
  52                         reg);
  53 out:
  54         return ret;
  55 }
  56
  57 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is too device
  58  * specific to be rolled into the core.
  59  */
  60 static irqreturn_t ade7758_trigger_handler(int irq, void *p)
  61 {
  62         struct iio_poll_func *pf = p;
  63         struct iio_dev *indio_dev = pf->indio_dev;
  64         struct ade7758_state *st = iio_priv(indio_dev);
  65         s64 dat64[2];
  66         u32 *dat32 = (u32 *)dat64;
  67
  68         if (!bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
  69                 if (ade7758_spi_read_burst(indio_dev) >= 0)
  70                         *dat32 = get_unaligned_be32(&st->rx_buf[5]) & 0xFFFFFF;
  71
  72         /* Guaranteed to be aligned with 8 byte boundary */
  73         if (indio_dev->scan_timestamp)
  74                 dat64[1] = pf->timestamp;
  75
  76         iio_push_to_buffers(indio_dev, (u8 *)dat64);
  77
  78         iio_trigger_notify_done(indio_dev->trig);
  79
  80         return IRQ_HANDLED;
  81 }
  82
  83 /**
  84  * ade7758_ring_preenable() setup the parameters of the ring before enabling
  85  *
  86  * The complex nature of the setting of the number of bytes per datum is due
  87  * to this driver currently ensuring that the timestamp is stored at an 8
  88  * byte boundary.
  89  **/
  90 static int ade7758_ring_preenable(struct iio_dev *indio_dev)
  91 {
  92         struct ade7758_state *st = iio_priv(indio_dev);
  93         unsigned channel;
  94         int ret;
  95
  96         if (!bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
  97                 return -EINVAL;
  98
  99         ret = iio_sw_buffer_preenable(indio_dev);
 100         if (ret < 0)
 101                 return ret;
 102
 103         channel = find_first_bit(indio_dev->active_scan_mask,
 104                                  indio_dev->masklength);
 105
 106         ade7758_write_waveform_type(&indio_dev->dev,
 107                 st->ade7758_ring_channels[channel].address);
 108
 109         return 0;
 110 }
 111
 112 static const struct iio_buffer_setup_ops ade7758_ring_setup_ops = {
 113         .preenable = &ade7758_ring_preenable,
 114         .postenable = &iio_triggered_buffer_postenable,
 115         .predisable = &iio_triggered_buffer_predisable,
 116         .validate_scan_mask = &iio_validate_scan_mask_onehot,
 117 };
 118
 119 void ade7758_unconfigure_ring(struct iio_dev *indio_dev)
 120 {
 121         iio_dealloc_pollfunc(indio_dev->pollfunc);
 122         iio_kfifo_free(indio_dev->buffer);
 123 }
 124
 125 int ade7758_configure_ring(struct iio_dev *indio_dev)
 126 {
 127         struct ade7758_state *st = iio_priv(indio_dev);
 128         int ret = 0;
 129
 130         indio_dev->buffer = iio_kfifo_allocate(indio_dev);
 131         if (!indio_dev->buffer) {
 132                 ret = -ENOMEM;
 133                 return ret;
 134         }
 135
 136         indio_dev->setup_ops = &ade7758_ring_setup_ops;
 137
 138         indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
 139                                                  &ade7758_trigger_handler,
 140                                                  0,
 141                                                  indio_dev,
 142                                                  "ade7759_consumer%d",
 143                                                  indio_dev->id);
 144         if (indio_dev->pollfunc == NULL) {
 145                 ret = -ENOMEM;
 146                 goto error_iio_kfifo_free;
 147         }
 148
 149         indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
 150
 151         st->tx_buf[0] = ADE7758_READ_REG(ADE7758_RSTATUS);
 152         st->tx_buf[1] = 0;
 153         st->tx_buf[2] = 0;
 154         st->tx_buf[3] = 0;
 155         st->tx_buf[4] = ADE7758_READ_REG(ADE7758_WFORM);
 156         st->tx_buf[5] = 0;
 157         st->tx_buf[6] = 0;
 158         st->tx_buf[7] = 0;
 159
 160         /* build spi ring message */
 161         st->ring_xfer[0].tx_buf = &st->tx_buf[0];
 162         st->ring_xfer[0].len = 1;
 163         st->ring_xfer[0].bits_per_word = 8;
 164         st->ring_xfer[0].delay_usecs = 4;
 165         st->ring_xfer[1].rx_buf = &st->rx_buf[1];
 166         st->ring_xfer[1].len = 3;
 167         st->ring_xfer[1].bits_per_word = 8;
 168         st->ring_xfer[1].cs_change = 1;
 169
 170         st->ring_xfer[2].tx_buf = &st->tx_buf[4];
 171         st->ring_xfer[2].len = 1;
 172         st->ring_xfer[2].bits_per_word = 8;
 173         st->ring_xfer[2].delay_usecs = 1;
 174         st->ring_xfer[3].rx_buf = &st->rx_buf[5];
 175         st->ring_xfer[3].len = 3;
 176         st->ring_xfer[3].bits_per_word = 8;
 177
 178         spi_message_init(&st->ring_msg);
 179         spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
 180         spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
 181         spi_message_add_tail(&st->ring_xfer[2], &st->ring_msg);
 182         spi_message_add_tail(&st->ring_xfer[3], &st->ring_msg);
 183
 184         return 0;
 185
 186 error_iio_kfifo_free:
 187         iio_kfifo_free(indio_dev->buffer);
 188         return ret;
 189 }
 190
 191 void ade7758_uninitialize_ring(struct iio_dev *indio_dev)
 192 {
 193         iio_buffer_unregister(indio_dev);
 194 }