diff options
Diffstat (limited to 'drivers/staging/iio/meter/ade7758_ring.c')
| -rw-r--r-- | drivers/staging/iio/meter/ade7758_ring.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/drivers/staging/iio/meter/ade7758_ring.c b/drivers/staging/iio/meter/ade7758_ring.c new file mode 100644 index 000000000000..274b4a07808c --- /dev/null +++ b/drivers/staging/iio/meter/ade7758_ring.c @@ -0,0 +1,212 @@ +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/gpio.h> +#include <linux/workqueue.h> +#include <linux/mutex.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/spi/spi.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/list.h> + +#include "../iio.h" +#include "../sysfs.h" +#include "../ring_sw.h" +#include "../accel/accel.h" +#include "../trigger.h" +#include "ade7758.h" + +/** + * combine_8_to_32() utility function to munge to u8s into u32 + **/ +static inline u32 combine_8_to_32(u8 lower, u8 mid, u8 upper) +{ + u32 _lower = lower; + u32 _mid = mid; + u32 _upper = upper; + + return _lower | (_mid << 8) | (_upper << 16); +} + +static IIO_SCAN_EL_C(wform, ADE7758_SCAN_WFORM, ADE7758_WFORM, NULL); +static IIO_CONST_ATTR_SCAN_EL_TYPE(wform, s, 24, 32); +static IIO_SCAN_EL_TIMESTAMP(1); +static IIO_CONST_ATTR_SCAN_EL_TYPE(timestamp, s, 64, 64); + +static struct attribute *ade7758_scan_el_attrs[] = { + &iio_scan_el_wform.dev_attr.attr, + &iio_const_attr_wform_index.dev_attr.attr, + &iio_const_attr_wform_type.dev_attr.attr, + &iio_scan_el_timestamp.dev_attr.attr, + &iio_const_attr_timestamp_index.dev_attr.attr, + &iio_const_attr_timestamp_type.dev_attr.attr, + NULL, +}; + +static struct attribute_group ade7758_scan_el_group = { + .attrs = ade7758_scan_el_attrs, + .name = "scan_elements", +}; + +/** + * ade7758_poll_func_th() top half interrupt handler called by trigger + * @private_data: iio_dev + **/ +static void ade7758_poll_func_th(struct iio_dev *indio_dev, s64 time) +{ + struct ade7758_state *st = iio_dev_get_devdata(indio_dev); + st->last_timestamp = time; + schedule_work(&st->work_trigger_to_ring); + /* Indicate that this interrupt is being handled */ + + /* Technically this is trigger related, but without this + * handler running there is currently no way for the interrupt + * to clear. + */ +} + +/** + * ade7758_spi_read_burst() - read all data registers + * @dev: device associated with child of actual device (iio_dev or iio_trig) + * @rx: somewhere to pass back the value read (min size is 24 bytes) + **/ +static int ade7758_spi_read_burst(struct device *dev, u8 *rx) +{ + struct spi_message msg; + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct ade7758_state *st = iio_dev_get_devdata(indio_dev); + int ret; + + struct spi_transfer xfers[] = { + { + .tx_buf = st->tx, + .rx_buf = rx, + .bits_per_word = 8, + .len = 4, + }, { + .tx_buf = st->tx + 4, + .rx_buf = rx, + .bits_per_word = 8, + .len = 4, + }, + }; + + mutex_lock(&st->buf_lock); + st->tx[0] = ADE7758_READ_REG(ADE7758_RSTATUS); + st->tx[1] = 0; + st->tx[2] = 0; + st->tx[3] = 0; + st->tx[4] = ADE7758_READ_REG(ADE7758_WFORM); + st->tx[5] = 0; + st->tx[6] = 0; + st->tx[7] = 0; + + spi_message_init(&msg); + spi_message_add_tail(&xfers[0], &msg); + spi_message_add_tail(&xfers[1], &msg); + ret = spi_sync(st->us, &msg); + if (ret) + dev_err(&st->us->dev, "problem when reading WFORM value\n"); + + mutex_unlock(&st->buf_lock); + + return ret; +} + +/* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device + * specific to be rolled into the core. + */ +static void ade7758_trigger_bh_to_ring(struct work_struct *work_s) +{ + struct ade7758_state *st + = container_of(work_s, struct ade7758_state, + work_trigger_to_ring); + struct iio_ring_buffer *ring = st->indio_dev->ring; + + int i = 0; + s32 *data; + size_t datasize = ring->access.get_bytes_per_datum(ring); + + data = kmalloc(datasize, GFP_KERNEL); + if (data == NULL) { + dev_err(&st->us->dev, "memory alloc failed in ring bh"); + return; + } + + if (ring->scan_count) + if (ade7758_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0) + for (; i < ring->scan_count; i++) + data[i] = combine_8_to_32(st->rx[i*2+2], + st->rx[i*2+1], + st->rx[i*2]); + + /* Guaranteed to be aligned with 8 byte boundary */ + if (ring->scan_timestamp) + *((s64 *) + (((u32)data + 4 * ring->scan_count + 4) & ~0x7)) = + st->last_timestamp; + + ring->access.store_to(ring, + (u8 *)data, + st->last_timestamp); + + iio_trigger_notify_done(st->indio_dev->trig); + kfree(data); + + return; +} + +void ade7758_unconfigure_ring(struct iio_dev *indio_dev) +{ + kfree(indio_dev->pollfunc); + iio_sw_rb_free(indio_dev->ring); +} + +int ade7758_configure_ring(struct iio_dev *indio_dev) +{ + int ret = 0; + struct ade7758_state *st = indio_dev->dev_data; + struct iio_ring_buffer *ring; + INIT_WORK(&st->work_trigger_to_ring, ade7758_trigger_bh_to_ring); + + ring = iio_sw_rb_allocate(indio_dev); + if (!ring) { + ret = -ENOMEM; + return ret; + } + indio_dev->ring = ring; + /* Effectively select the ring buffer implementation */ + iio_ring_sw_register_funcs(&ring->access); + ring->bpe = 4; + ring->scan_el_attrs = &ade7758_scan_el_group; + ring->scan_timestamp = true; + ring->preenable = &iio_sw_ring_preenable; + ring->postenable = &iio_triggered_ring_postenable; + ring->predisable = &iio_triggered_ring_predisable; + ring->owner = THIS_MODULE; + + /* Set default scan mode */ + iio_scan_mask_set(ring, iio_scan_el_wform.number); + + ret = iio_alloc_pollfunc(indio_dev, NULL, &ade7758_poll_func_th); + if (ret) + goto error_iio_sw_rb_free; + + indio_dev->modes |= INDIO_RING_TRIGGERED; + return 0; + +error_iio_sw_rb_free: + iio_sw_rb_free(indio_dev->ring); + return ret; +} + +int ade7758_initialize_ring(struct iio_ring_buffer *ring) +{ + return iio_ring_buffer_register(ring, 0); +} + +void ade7758_uninitialize_ring(struct iio_ring_buffer *ring) +{ + iio_ring_buffer_unregister(ring); +} |