| /* |
| * Copyright (C) 2008 Jonathan Cameron |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * max1363_ring.c |
| */ |
| |
| #include <linux/interrupt.h> |
| #include <linux/gpio.h> |
| #include <linux/workqueue.h> |
| #include <linux/device.h> |
| #include <linux/slab.h> |
| #include <linux/kernel.h> |
| #include <linux/sysfs.h> |
| #include <linux/list.h> |
| #include <linux/i2c.h> |
| #include <linux/bitops.h> |
| |
| #include "../iio.h" |
| #include "../ring_generic.h" |
| #include "../ring_sw.h" |
| #include "../trigger.h" |
| #include "../sysfs.h" |
| |
| #include "max1363.h" |
| |
| /* Todo: test this */ |
| int max1363_single_channel_from_ring(long mask, struct max1363_state *st) |
| { |
| unsigned long numvals; |
| int count = 0, ret; |
| u8 *ring_data; |
| if (!(st->current_mode->modemask & mask)) { |
| ret = -EBUSY; |
| goto error_ret; |
| } |
| numvals = hweight_long(st->current_mode->modemask); |
| |
| ring_data = kmalloc(numvals*2, GFP_KERNEL); |
| if (ring_data == NULL) { |
| ret = -ENOMEM; |
| goto error_ret; |
| } |
| ret = st->indio_dev->ring->access.read_last(st->indio_dev->ring, |
| ring_data); |
| if (ret) |
| goto error_free_ring_data; |
| /* Need a count of channels prior to this one */ |
| mask >>= 1; |
| while (mask) { |
| if (mask & st->current_mode->modemask) |
| count++; |
| mask >>= 1; |
| } |
| if (st->chip_info->bits != 8) |
| ret = ((int)(ring_data[count*2 + 0] & 0x0F) << 8) |
| + (int)(ring_data[count*2 + 1]); |
| else |
| ret = ring_data[count]; |
| |
| error_free_ring_data: |
| kfree(ring_data); |
| error_ret: |
| return ret; |
| } |
| |
| /** |
| * max1363_ring_preenable() setup the parameters of the ring before enabling |
| * |
| * The complex nature of the setting of the nuber of bytes per datum is due |
| * to this driver currently ensuring that the timestamp is stored at an 8 |
| * byte boundary. |
| **/ |
| static int max1363_ring_preenable(struct iio_dev *indio_dev) |
| { |
| struct max1363_state *st = indio_dev->dev_data; |
| size_t d_size; |
| unsigned long numvals; |
| |
| /* |
| * Need to figure out the current mode based upon the requested |
| * scan mask in iio_dev |
| */ |
| st->current_mode = max1363_match_mode(st->indio_dev->scan_mask, |
| st->chip_info); |
| if (!st->current_mode) |
| return -EINVAL; |
| |
| max1363_set_scan_mode(st); |
| |
| numvals = hweight_long(st->current_mode->modemask); |
| if (indio_dev->ring->access.set_bpd) { |
| if (st->chip_info->bits != 8) |
| d_size = numvals*2 + sizeof(s64); |
| else |
| d_size = numvals + sizeof(s64); |
| if (d_size % 8) |
| d_size += 8 - (d_size % 8); |
| indio_dev->ring->access.set_bpd(indio_dev->ring, d_size); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * max1363_ring_postenable() typical ring post enable |
| * |
| * Only not moved into the core for the hardware ring buffer cases |
| * that are more sophisticated. |
| **/ |
| static int max1363_ring_postenable(struct iio_dev *indio_dev) |
| { |
| if (indio_dev->trig == NULL) |
| return 0; |
| return iio_trigger_attach_poll_func(indio_dev->trig, |
| indio_dev->pollfunc); |
| } |
| |
| /** |
| * max1363_ring_predisable() runs just prior to ring buffer being disabled |
| * |
| * Typical predisable function which ensures that no trigger events can |
| * occur before we disable the ring buffer (and hence would have no idea |
| * what to do with them) |
| **/ |
| static int max1363_ring_predisable(struct iio_dev *indio_dev) |
| { |
| if (indio_dev->trig) |
| return iio_trigger_dettach_poll_func(indio_dev->trig, |
| indio_dev->pollfunc); |
| else |
| return 0; |
| } |
| |
| /** |
| * max1363_poll_func_th() th of trigger launched polling to ring buffer |
| * |
| * As sampling only occurs on i2c comms occuring, leave timestamping until |
| * then. Some triggers will generate their own time stamp. Currently |
| * there is no way of notifying them when no one cares. |
| **/ |
| static void max1363_poll_func_th(struct iio_dev *indio_dev) |
| { |
| struct max1363_state *st = indio_dev->dev_data; |
| |
| schedule_work(&st->poll_work); |
| |
| return; |
| } |
| /** |
| * max1363_poll_bh_to_ring() bh of trigger launched polling to ring buffer |
| * @work_s: the work struct through which this was scheduled |
| * |
| * Currently there is no option in this driver to disable the saving of |
| * timestamps within the ring. |
| * I think the one copy of this at a time was to avoid problems if the |
| * trigger was set far too high and the reads then locked up the computer. |
| **/ |
| static void max1363_poll_bh_to_ring(struct work_struct *work_s) |
| { |
| struct max1363_state *st = container_of(work_s, struct max1363_state, |
| poll_work); |
| struct iio_dev *indio_dev = st->indio_dev; |
| struct iio_sw_ring_buffer *ring = iio_to_sw_ring(indio_dev->ring); |
| s64 time_ns; |
| __u8 *rxbuf; |
| int b_sent; |
| size_t d_size; |
| unsigned long numvals = hweight_long(st->current_mode->modemask); |
| |
| /* Ensure the timestamp is 8 byte aligned */ |
| if (st->chip_info->bits != 8) |
| d_size = numvals*2 + sizeof(s64); |
| else |
| d_size = numvals + sizeof(s64); |
| if (d_size % sizeof(s64)) |
| d_size += sizeof(s64) - (d_size % sizeof(s64)); |
| |
| /* Ensure only one copy of this function running at a time */ |
| if (atomic_inc_return(&st->protect_ring) > 1) |
| return; |
| |
| /* Monitor mode prevents reading. Whilst not currently implemented |
| * might as well have this test in here in the meantime as it does |
| * no harm. |
| */ |
| if (numvals == 0) |
| return; |
| |
| rxbuf = kmalloc(d_size, GFP_KERNEL); |
| if (rxbuf == NULL) |
| return; |
| if (st->chip_info->bits != 8) |
| b_sent = i2c_master_recv(st->client, rxbuf, numvals*2); |
| else |
| b_sent = i2c_master_recv(st->client, rxbuf, numvals); |
| if (b_sent < 0) |
| goto done; |
| |
| time_ns = iio_get_time_ns(); |
| |
| memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns)); |
| |
| indio_dev->ring->access.store_to(&ring->buf, rxbuf, time_ns); |
| done: |
| kfree(rxbuf); |
| atomic_dec(&st->protect_ring); |
| } |
| |
| |
| int max1363_register_ring_funcs_and_init(struct iio_dev *indio_dev) |
| { |
| struct max1363_state *st = indio_dev->dev_data; |
| int ret = 0; |
| |
| indio_dev->ring = iio_sw_rb_allocate(indio_dev); |
| if (!indio_dev->ring) { |
| ret = -ENOMEM; |
| goto error_ret; |
| } |
| /* Effectively select the ring buffer implementation */ |
| iio_ring_sw_register_funcs(&st->indio_dev->ring->access); |
| indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL); |
| if (indio_dev->pollfunc == NULL) { |
| ret = -ENOMEM; |
| goto error_deallocate_sw_rb; |
| } |
| /* Configure the polling function called on trigger interrupts */ |
| indio_dev->pollfunc->poll_func_main = &max1363_poll_func_th; |
| indio_dev->pollfunc->private_data = indio_dev; |
| |
| /* Ring buffer functions - here trigger setup related */ |
| indio_dev->ring->postenable = &max1363_ring_postenable; |
| indio_dev->ring->preenable = &max1363_ring_preenable; |
| indio_dev->ring->predisable = &max1363_ring_predisable; |
| INIT_WORK(&st->poll_work, &max1363_poll_bh_to_ring); |
| |
| /* Flag that polled ring buffering is possible */ |
| indio_dev->modes |= INDIO_RING_TRIGGERED; |
| return 0; |
| error_deallocate_sw_rb: |
| iio_sw_rb_free(indio_dev->ring); |
| error_ret: |
| return ret; |
| } |
| |
| void max1363_ring_cleanup(struct iio_dev *indio_dev) |
| { |
| /* ensure that the trigger has been detached */ |
| if (indio_dev->trig) { |
| iio_put_trigger(indio_dev->trig); |
| iio_trigger_dettach_poll_func(indio_dev->trig, |
| indio_dev->pollfunc); |
| } |
| kfree(indio_dev->pollfunc); |
| iio_sw_rb_free(indio_dev->ring); |
| } |
| |
| void max1363_uninitialize_ring(struct iio_ring_buffer *ring) |
| { |
| iio_ring_buffer_unregister(ring); |
| }; |
| |
| int max1363_initialize_ring(struct iio_ring_buffer *ring) |
| { |
| return iio_ring_buffer_register(ring, 0); |
| }; |