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/interrupt.h>
   9 #include <linux/irq.h>
  10 #include <linux/gpio.h>
  11 #include <linux/workqueue.h>
  12 #include <linux/mutex.h>
  13 #include <linux/device.h>
  14 #include <linux/kernel.h>
  15 #include <linux/spi/spi.h>
  16 #include <linux/slab.h>
  17 #include <linux/sysfs.h>
  18 #include <linux/list.h>
  19 #include <asm/unaligned.h>
  20
  21 #include "../iio.h"
  22 #include "../sysfs.h"
  23 #include "../ring_sw.h"
  24 #include "../accel/accel.h"
  25 #include "../trigger.h"
  26 #include "ade7758.h"
  27
  28 /**
  29  * ade7758_spi_read_burst() - read data registers
  30  * @dev: device associated with child of actual device (iio_dev or iio_trig)
  31  **/
  32 static int ade7758_spi_read_burst(struct device *dev)
  33 {
  34         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  35         struct ade7758_state *st = iio_priv(indio_dev);
  36         int ret;
  37
  38         ret = spi_sync(st->us, &st->ring_msg);
  39         if (ret)
  40                 dev_err(&st->us->dev, "problem when reading WFORM value\n");
  41
  42         return ret;
  43 }
  44
  45 static int ade7758_write_waveform_type(struct device *dev, unsigned type)
  46 {
  47         int ret;
  48         u8 reg;
  49
  50         ret = ade7758_spi_read_reg_8(dev,
  51                         ADE7758_WAVMODE,
  52                         &reg);
  53         if (ret)
  54                 goto out;
  55
  56         reg &= ~0x1F;
  57         reg |= type & 0x1F;
  58
  59         ret = ade7758_spi_write_reg_8(dev,
  60                         ADE7758_WAVMODE,
  61                         reg);
  62 out:
  63         return ret;
  64 }
  65
  66 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
  67  * specific to be rolled into the core.
  68  */
  69 static irqreturn_t ade7758_trigger_handler(int irq, void *p)
  70 {
  71         struct iio_poll_func *pf = p;
  72         struct iio_dev *indio_dev = pf->private_data;
  73         struct iio_ring_buffer *ring = indio_dev->ring;
  74         struct ade7758_state *st = iio_priv(indio_dev);
  75         s64 dat64[2];
  76         u32 *dat32 = (u32 *)dat64;
  77
  78         if (ring->scan_count)
  79                 if (ade7758_spi_read_burst(&indio_dev->dev) >= 0)
  80                         *dat32 = get_unaligned_be32(&st->rx_buf[5]) & 0xFFFFFF;
  81
  82         /* Guaranteed to be aligned with 8 byte boundary */
  83         if (ring->scan_timestamp)
  84                 dat64[1] = pf->timestamp;
  85
  86         ring->access->store_to(ring, (u8 *)dat64, pf->timestamp);
  87
  88         iio_trigger_notify_done(indio_dev->trig);
  89
  90         return IRQ_HANDLED;
  91 }
  92
  93 /**
  94  * ade7758_ring_preenable() setup the parameters of the ring before enabling
  95  *
  96  * The complex nature of the setting of the nuber of bytes per datum is due
  97  * to this driver currently ensuring that the timestamp is stored at an 8
  98  * byte boundary.
  99  **/
 100 static int ade7758_ring_preenable(struct iio_dev *indio_dev)
 101 {
 102         struct ade7758_state *st = iio_priv(indio_dev);
 103         struct iio_ring_buffer *ring = indio_dev->ring;
 104         size_t d_size;
 105         unsigned channel;
 106
 107         if (!ring->scan_count)
 108                 return -EINVAL;
 109
 110         channel = __ffs(ring->scan_mask);
 111
 112         d_size = st->ade7758_ring_channels[channel].scan_type.storagebits / 8;
 113
 114         if (ring->scan_timestamp) {
 115                 d_size += sizeof(s64);
 116
 117                 if (d_size % sizeof(s64))
 118                         d_size += sizeof(s64) - (d_size % sizeof(s64));
 119         }
 120
 121         if (indio_dev->ring->access->set_bytes_per_datum)
 122                 indio_dev->ring->access->set_bytes_per_datum(indio_dev->ring,
 123                                                             d_size);
 124
 125         ade7758_write_waveform_type(&indio_dev->dev,
 126                 st->ade7758_ring_channels[channel].address);
 127
 128         return 0;
 129 }
 130
 131 static const struct iio_ring_setup_ops ade7758_ring_setup_ops = {
 132         .preenable = &ade7758_ring_preenable,
 133         .postenable = &iio_triggered_ring_postenable,
 134         .predisable = &iio_triggered_ring_predisable,
 135 };
 136
 137 void ade7758_unconfigure_ring(struct iio_dev *indio_dev)
 138 {
 139         /* ensure that the trigger has been detached */
 140         if (indio_dev->trig) {
 141                 iio_put_trigger(indio_dev->trig);
 142                 iio_trigger_dettach_poll_func(indio_dev->trig,
 143                                               indio_dev->pollfunc);
 144         }
 145         kfree(indio_dev->pollfunc->name);
 146         kfree(indio_dev->pollfunc);
 147         iio_sw_rb_free(indio_dev->ring);
 148 }
 149
 150 int ade7758_configure_ring(struct iio_dev *indio_dev)
 151 {
 152         struct ade7758_state *st = iio_priv(indio_dev);
 153         int ret = 0;
 154
 155         indio_dev->ring = iio_sw_rb_allocate(indio_dev);
 156         if (!indio_dev->ring) {
 157                 ret = -ENOMEM;
 158                 return ret;
 159         }
 160
 161         /* Effectively select the ring buffer implementation */
 162         indio_dev->ring->access = &ring_sw_access_funcs;
 163         indio_dev->ring->setup_ops = &ade7758_ring_setup_ops;
 164         indio_dev->ring->owner = THIS_MODULE;
 165
 166         indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
 167         if (indio_dev->pollfunc == NULL) {
 168                 ret = -ENOMEM;
 169                 goto error_iio_sw_rb_free;
 170         }
 171         indio_dev->pollfunc->private_data = indio_dev;
 172         indio_dev->pollfunc->h = &iio_pollfunc_store_time;
 173         indio_dev->pollfunc->thread = &ade7758_trigger_handler;
 174         indio_dev->pollfunc->name
 175                 = kasprintf(GFP_KERNEL, "ade7759_consumer%d", indio_dev->id);
 176         if (indio_dev->pollfunc->name == NULL) {
 177                 ret = -ENOMEM;
 178                 goto error_free_pollfunc;
 179         }
 180         indio_dev->modes |= INDIO_RING_TRIGGERED;
 181
 182         st->tx_buf[0] = ADE7758_READ_REG(ADE7758_RSTATUS);
 183         st->tx_buf[1] = 0;
 184         st->tx_buf[2] = 0;
 185         st->tx_buf[3] = 0;
 186         st->tx_buf[4] = ADE7758_READ_REG(ADE7758_WFORM);
 187         st->tx_buf[5] = 0;
 188         st->tx_buf[6] = 0;
 189         st->tx_buf[7] = 0;
 190
 191         /* build spi ring message */
 192         st->ring_xfer[0].tx_buf = &st->tx_buf[0];
 193         st->ring_xfer[0].len = 1;
 194         st->ring_xfer[0].bits_per_word = 8;
 195         st->ring_xfer[0].delay_usecs = 4;
 196         st->ring_xfer[1].rx_buf = &st->rx_buf[1];
 197         st->ring_xfer[1].len = 3;
 198         st->ring_xfer[1].bits_per_word = 8;
 199         st->ring_xfer[1].cs_change = 1;
 200
 201         st->ring_xfer[2].tx_buf = &st->tx_buf[4];
 202         st->ring_xfer[2].len = 1;
 203         st->ring_xfer[2].bits_per_word = 8;
 204         st->ring_xfer[2].delay_usecs = 1;
 205         st->ring_xfer[3].rx_buf = &st->rx_buf[5];
 206         st->ring_xfer[3].len = 3;
 207         st->ring_xfer[3].bits_per_word = 8;
 208
 209         spi_message_init(&st->ring_msg);
 210         spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
 211         spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
 212         spi_message_add_tail(&st->ring_xfer[2], &st->ring_msg);
 213         spi_message_add_tail(&st->ring_xfer[3], &st->ring_msg);
 214
 215         return 0;
 216
 217 error_free_pollfunc:
 218         kfree(indio_dev->pollfunc);
 219 error_iio_sw_rb_free:
 220         iio_sw_rb_free(indio_dev->ring);
 221         return ret;
 222 }
 223
 224 void ade7758_uninitialize_ring(struct iio_ring_buffer *ring)
 225 {
 226         iio_ring_buffer_unregister(ring);
 227 }