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 **/
ade7758_spi_read_burst(struct iio_dev * indio_dev)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
ade7758_write_waveform_type(struct device * dev,unsigned type)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 ®);
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 */
ade7758_trigger_handler(int irq,void * p)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 iio_push_to_buffers_with_timestamp(indio_dev, dat64, pf->timestamp);
73
74 iio_trigger_notify_done(indio_dev->trig);
75
76 return IRQ_HANDLED;
77 }
78
79 /**
80 * ade7758_ring_preenable() setup the parameters of the ring before enabling
81 *
82 * The complex nature of the setting of the number of bytes per datum is due
83 * to this driver currently ensuring that the timestamp is stored at an 8
84 * byte boundary.
85 **/
ade7758_ring_preenable(struct iio_dev * indio_dev)86 static int ade7758_ring_preenable(struct iio_dev *indio_dev)
87 {
88 unsigned channel;
89
90 if (bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
91 return -EINVAL;
92
93 channel = find_first_bit(indio_dev->active_scan_mask,
94 indio_dev->masklength);
95
96 ade7758_write_waveform_type(&indio_dev->dev,
97 indio_dev->channels[channel].address);
98
99 return 0;
100 }
101
102 static const struct iio_buffer_setup_ops ade7758_ring_setup_ops = {
103 .preenable = &ade7758_ring_preenable,
104 .postenable = &iio_triggered_buffer_postenable,
105 .predisable = &iio_triggered_buffer_predisable,
106 .validate_scan_mask = &iio_validate_scan_mask_onehot,
107 };
108
ade7758_unconfigure_ring(struct iio_dev * indio_dev)109 void ade7758_unconfigure_ring(struct iio_dev *indio_dev)
110 {
111 iio_dealloc_pollfunc(indio_dev->pollfunc);
112 iio_kfifo_free(indio_dev->buffer);
113 }
114
ade7758_configure_ring(struct iio_dev * indio_dev)115 int ade7758_configure_ring(struct iio_dev *indio_dev)
116 {
117 struct ade7758_state *st = iio_priv(indio_dev);
118 struct iio_buffer *buffer;
119 int ret = 0;
120
121 buffer = iio_kfifo_allocate();
122 if (!buffer)
123 return -ENOMEM;
124
125 iio_device_attach_buffer(indio_dev, buffer);
126
127 indio_dev->setup_ops = &ade7758_ring_setup_ops;
128
129 indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
130 &ade7758_trigger_handler,
131 0,
132 indio_dev,
133 "ade7759_consumer%d",
134 indio_dev->id);
135 if (!indio_dev->pollfunc) {
136 ret = -ENOMEM;
137 goto error_iio_kfifo_free;
138 }
139
140 indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
141
142 st->tx_buf[0] = ADE7758_READ_REG(ADE7758_RSTATUS);
143 st->tx_buf[1] = 0;
144 st->tx_buf[2] = 0;
145 st->tx_buf[3] = 0;
146 st->tx_buf[4] = ADE7758_READ_REG(ADE7758_WFORM);
147 st->tx_buf[5] = 0;
148 st->tx_buf[6] = 0;
149 st->tx_buf[7] = 0;
150
151 /* build spi ring message */
152 st->ring_xfer[0].tx_buf = &st->tx_buf[0];
153 st->ring_xfer[0].len = 1;
154 st->ring_xfer[0].bits_per_word = 8;
155 st->ring_xfer[0].delay_usecs = 4;
156 st->ring_xfer[1].rx_buf = &st->rx_buf[1];
157 st->ring_xfer[1].len = 3;
158 st->ring_xfer[1].bits_per_word = 8;
159 st->ring_xfer[1].cs_change = 1;
160
161 st->ring_xfer[2].tx_buf = &st->tx_buf[4];
162 st->ring_xfer[2].len = 1;
163 st->ring_xfer[2].bits_per_word = 8;
164 st->ring_xfer[2].delay_usecs = 1;
165 st->ring_xfer[3].rx_buf = &st->rx_buf[5];
166 st->ring_xfer[3].len = 3;
167 st->ring_xfer[3].bits_per_word = 8;
168
169 spi_message_init(&st->ring_msg);
170 spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
171 spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
172 spi_message_add_tail(&st->ring_xfer[2], &st->ring_msg);
173 spi_message_add_tail(&st->ring_xfer[3], &st->ring_msg);
174
175 return 0;
176
177 error_iio_kfifo_free:
178 iio_kfifo_free(indio_dev->buffer);
179 return ret;
180 }
181