diff options
author | Jonathan Cameron <jic23@kernel.org> | 2012-06-30 23:06:00 +0400 |
---|---|---|
committer | Jonathan Cameron <jic23@kernel.org> | 2012-11-10 14:17:21 +0400 |
commit | 84b36ce5f79c01f792c623f14e92ed86cdccb42f (patch) | |
tree | aa763089df10007bc42aa02b747e652e0b99003e /drivers/iio/industrialio-buffer.c | |
parent | 4eb3ccf157639a9d9c7829de94017c46c73d9cc4 (diff) | |
download | linux-84b36ce5f79c01f792c623f14e92ed86cdccb42f.tar.xz |
staging:iio: Add support for multiple buffers
Route all buffer writes through the demux.
Addition or removal of a buffer results in tear down and
setup of all the buffers for a given device.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Tested-by: srinivas pandruvada <srinivas.pandruvada@intel.com>
Diffstat (limited to 'drivers/iio/industrialio-buffer.c')
-rw-r--r-- | drivers/iio/industrialio-buffer.c | 380 |
1 files changed, 263 insertions, 117 deletions
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 722a83fd8d85..aaadd32f9f0d 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -31,6 +31,18 @@ static const char * const iio_endian_prefix[] = { [IIO_LE] = "le", }; +static bool iio_buffer_is_active(struct iio_dev *indio_dev, + struct iio_buffer *buf) +{ + struct list_head *p; + + list_for_each(p, &indio_dev->buffer_list) + if (p == &buf->buffer_list) + return true; + + return false; +} + /** * iio_buffer_read_first_n_outer() - chrdev read for buffer access * @@ -134,7 +146,7 @@ static ssize_t iio_scan_el_store(struct device *dev, if (ret < 0) return ret; mutex_lock(&indio_dev->mlock); - if (iio_buffer_enabled(indio_dev)) { + if (iio_buffer_is_active(indio_dev, indio_dev->buffer)) { ret = -EBUSY; goto error_ret; } @@ -180,12 +192,11 @@ static ssize_t iio_scan_el_ts_store(struct device *dev, return ret; mutex_lock(&indio_dev->mlock); - if (iio_buffer_enabled(indio_dev)) { + if (iio_buffer_is_active(indio_dev, indio_dev->buffer)) { ret = -EBUSY; goto error_ret; } indio_dev->buffer->scan_timestamp = state; - indio_dev->scan_timestamp = state; error_ret: mutex_unlock(&indio_dev->mlock); @@ -385,7 +396,7 @@ ssize_t iio_buffer_write_length(struct device *dev, return len; mutex_lock(&indio_dev->mlock); - if (iio_buffer_enabled(indio_dev)) { + if (iio_buffer_is_active(indio_dev, indio_dev->buffer)) { ret = -EBUSY; } else { if (buffer->access->set_length) @@ -398,102 +409,14 @@ ssize_t iio_buffer_write_length(struct device *dev, } EXPORT_SYMBOL(iio_buffer_write_length); -ssize_t iio_buffer_store_enable(struct device *dev, - struct device_attribute *attr, - const char *buf, - size_t len) -{ - int ret; - bool requested_state, current_state; - int previous_mode; - struct iio_dev *indio_dev = dev_to_iio_dev(dev); - struct iio_buffer *buffer = indio_dev->buffer; - - mutex_lock(&indio_dev->mlock); - previous_mode = indio_dev->currentmode; - requested_state = !(buf[0] == '0'); - current_state = iio_buffer_enabled(indio_dev); - if (current_state == requested_state) { - printk(KERN_INFO "iio-buffer, current state requested again\n"); - goto done; - } - if (requested_state) { - if (indio_dev->setup_ops->preenable) { - ret = indio_dev->setup_ops->preenable(indio_dev); - if (ret) { - printk(KERN_ERR - "Buffer not started: " - "buffer preenable failed\n"); - goto error_ret; - } - } - if (buffer->access->request_update) { - ret = buffer->access->request_update(buffer); - if (ret) { - printk(KERN_INFO - "Buffer not started: " - "buffer parameter update failed\n"); - goto error_ret; - } - } - /* Definitely possible for devices to support both of these. */ - if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) { - if (!indio_dev->trig) { - printk(KERN_INFO - "Buffer not started: no trigger\n"); - ret = -EINVAL; - goto error_ret; - } - indio_dev->currentmode = INDIO_BUFFER_TRIGGERED; - } else if (indio_dev->modes & INDIO_BUFFER_HARDWARE) - indio_dev->currentmode = INDIO_BUFFER_HARDWARE; - else { /* should never be reached */ - ret = -EINVAL; - goto error_ret; - } - - if (indio_dev->setup_ops->postenable) { - ret = indio_dev->setup_ops->postenable(indio_dev); - if (ret) { - printk(KERN_INFO - "Buffer not started: " - "postenable failed\n"); - indio_dev->currentmode = previous_mode; - if (indio_dev->setup_ops->postdisable) - indio_dev->setup_ops-> - postdisable(indio_dev); - goto error_ret; - } - } - } else { - if (indio_dev->setup_ops->predisable) { - ret = indio_dev->setup_ops->predisable(indio_dev); - if (ret) - goto error_ret; - } - indio_dev->currentmode = INDIO_DIRECT_MODE; - if (indio_dev->setup_ops->postdisable) { - ret = indio_dev->setup_ops->postdisable(indio_dev); - if (ret) - goto error_ret; - } - } -done: - mutex_unlock(&indio_dev->mlock); - return len; - -error_ret: - mutex_unlock(&indio_dev->mlock); - return ret; -} -EXPORT_SYMBOL(iio_buffer_store_enable); - ssize_t iio_buffer_show_enable(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); - return sprintf(buf, "%d\n", iio_buffer_enabled(indio_dev)); + return sprintf(buf, "%d\n", + iio_buffer_is_active(indio_dev, + indio_dev->buffer)); } EXPORT_SYMBOL(iio_buffer_show_enable); @@ -537,35 +460,220 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev, const long *mask, return bytes; } -int iio_sw_buffer_preenable(struct iio_dev *indio_dev) +int iio_update_buffers(struct iio_dev *indio_dev, + struct iio_buffer *insert_buffer, + struct iio_buffer *remove_buffer) { - struct iio_buffer *buffer = indio_dev->buffer; - dev_dbg(&indio_dev->dev, "%s\n", __func__); + int ret; + int success = 0; + struct iio_buffer *buffer; + unsigned long *compound_mask; + const unsigned long *old_mask; - /* How much space will the demuxed element take? */ - indio_dev->scan_bytes = - iio_compute_scan_bytes(indio_dev, buffer->scan_mask, - buffer->scan_timestamp); - buffer->access->set_bytes_per_datum(buffer, indio_dev->scan_bytes); + /* Wind down existing buffers - iff there are any */ + if (!list_empty(&indio_dev->buffer_list)) { + if (indio_dev->setup_ops->predisable) { + ret = indio_dev->setup_ops->predisable(indio_dev); + if (ret) + goto error_ret; + } + indio_dev->currentmode = INDIO_DIRECT_MODE; + if (indio_dev->setup_ops->postdisable) { + ret = indio_dev->setup_ops->postdisable(indio_dev); + if (ret) + goto error_ret; + } + } + /* Keep a copy of current setup to allow roll back */ + old_mask = indio_dev->active_scan_mask; + if (!indio_dev->available_scan_masks) + indio_dev->active_scan_mask = NULL; + + if (remove_buffer) + list_del(&remove_buffer->buffer_list); + if (insert_buffer) + list_add(&insert_buffer->buffer_list, &indio_dev->buffer_list); + + /* If no buffers in list, we are done */ + if (list_empty(&indio_dev->buffer_list)) { + indio_dev->currentmode = INDIO_DIRECT_MODE; + if (indio_dev->available_scan_masks == NULL) + kfree(old_mask); + return 0; + } /* What scan mask do we actually have ?*/ - if (indio_dev->available_scan_masks) + compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength), + sizeof(long), GFP_KERNEL); + if (compound_mask == NULL) { + if (indio_dev->available_scan_masks == NULL) + kfree(old_mask); + return -ENOMEM; + } + indio_dev->scan_timestamp = 0; + + list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { + bitmap_or(compound_mask, compound_mask, buffer->scan_mask, + indio_dev->masklength); + indio_dev->scan_timestamp |= buffer->scan_timestamp; + } + if (indio_dev->available_scan_masks) { indio_dev->active_scan_mask = iio_scan_mask_match(indio_dev->available_scan_masks, indio_dev->masklength, - buffer->scan_mask); - else - indio_dev->active_scan_mask = buffer->scan_mask; - - if (indio_dev->active_scan_mask == NULL) - return -EINVAL; + compound_mask); + if (indio_dev->active_scan_mask == NULL) { + /* + * Roll back. + * Note can only occur when adding a buffer. + */ + list_del(&insert_buffer->buffer_list); + indio_dev->active_scan_mask = old_mask; + success = -EINVAL; + } + } else { + indio_dev->active_scan_mask = compound_mask; + } iio_update_demux(indio_dev); - if (indio_dev->info->update_scan_mode) - return indio_dev->info + /* Wind up again */ + if (indio_dev->setup_ops->preenable) { + ret = indio_dev->setup_ops->preenable(indio_dev); + if (ret) { + printk(KERN_ERR + "Buffer not started:" + "buffer preenable failed\n"); + goto error_remove_inserted; + } + } + indio_dev->scan_bytes = + iio_compute_scan_bytes(indio_dev, + indio_dev->active_scan_mask, + indio_dev->scan_timestamp); + list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) + if (buffer->access->request_update) { + ret = buffer->access->request_update(buffer); + if (ret) { + printk(KERN_INFO + "Buffer not started:" + "buffer parameter update failed\n"); + goto error_run_postdisable; + } + } + if (indio_dev->info->update_scan_mode) { + ret = indio_dev->info ->update_scan_mode(indio_dev, indio_dev->active_scan_mask); + if (ret < 0) { + printk(KERN_INFO "update scan mode failed\n"); + goto error_run_postdisable; + } + } + /* Definitely possible for devices to support both of these.*/ + if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) { + if (!indio_dev->trig) { + printk(KERN_INFO "Buffer not started: no trigger\n"); + ret = -EINVAL; + /* Can only occur on first buffer */ + goto error_run_postdisable; + } + indio_dev->currentmode = INDIO_BUFFER_TRIGGERED; + } else if (indio_dev->modes & INDIO_BUFFER_HARDWARE) { + indio_dev->currentmode = INDIO_BUFFER_HARDWARE; + } else { /* should never be reached */ + ret = -EINVAL; + goto error_run_postdisable; + } + + if (indio_dev->setup_ops->postenable) { + ret = indio_dev->setup_ops->postenable(indio_dev); + if (ret) { + printk(KERN_INFO + "Buffer not started: postenable failed\n"); + indio_dev->currentmode = INDIO_DIRECT_MODE; + if (indio_dev->setup_ops->postdisable) + indio_dev->setup_ops->postdisable(indio_dev); + goto error_disable_all_buffers; + } + } + + if (indio_dev->available_scan_masks) + kfree(compound_mask); + else + kfree(old_mask); + + return success; + +error_disable_all_buffers: + indio_dev->currentmode = INDIO_DIRECT_MODE; +error_run_postdisable: + if (indio_dev->setup_ops->postdisable) + indio_dev->setup_ops->postdisable(indio_dev); +error_remove_inserted: + + if (insert_buffer) + list_del(&insert_buffer->buffer_list); + indio_dev->active_scan_mask = old_mask; + kfree(compound_mask); +error_ret: + + return ret; +} +EXPORT_SYMBOL_GPL(iio_update_buffers); + +ssize_t iio_buffer_store_enable(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t len) +{ + int ret; + bool requested_state; + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct iio_buffer *pbuf = indio_dev->buffer; + bool inlist; + + ret = strtobool(buf, &requested_state); + if (ret < 0) + return ret; + + mutex_lock(&indio_dev->mlock); + + /* Find out if it is in the list */ + inlist = iio_buffer_is_active(indio_dev, pbuf); + /* Already in desired state */ + if (inlist == requested_state) + goto done; + + if (requested_state) + ret = iio_update_buffers(indio_dev, + indio_dev->buffer, NULL); + else + ret = iio_update_buffers(indio_dev, + NULL, indio_dev->buffer); + + if (ret < 0) + goto done; +done: + mutex_unlock(&indio_dev->mlock); + return (ret < 0) ? ret : len; +} +EXPORT_SYMBOL(iio_buffer_store_enable); + +int iio_sw_buffer_preenable(struct iio_dev *indio_dev) +{ + struct iio_buffer *buffer; + unsigned bytes; + dev_dbg(&indio_dev->dev, "%s\n", __func__); + + list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) + if (buffer->access->set_bytes_per_datum) { + bytes = iio_compute_scan_bytes(indio_dev, + buffer->scan_mask, + buffer->scan_timestamp); + + buffer->access->set_bytes_per_datum(buffer, bytes); + } return 0; } EXPORT_SYMBOL(iio_sw_buffer_preenable); @@ -599,7 +707,11 @@ static bool iio_validate_scan_mask(struct iio_dev *indio_dev, * iio_scan_mask_set() - set particular bit in the scan mask * @buffer: the buffer whose scan mask we are interested in * @bit: the bit to be set. - **/ + * + * Note that at this point we have no way of knowing what other + * buffers might request, hence this code only verifies that the + * individual buffers request is plausible. + */ int iio_scan_mask_set(struct iio_dev *indio_dev, struct iio_buffer *buffer, int bit) { @@ -682,13 +794,12 @@ static unsigned char *iio_demux(struct iio_buffer *buffer, return buffer->demux_bounce; } -int iio_push_to_buffer(struct iio_buffer *buffer, unsigned char *data) +static int iio_push_to_buffer(struct iio_buffer *buffer, unsigned char *data) { unsigned char *dataout = iio_demux(buffer, data); return buffer->access->store_to(buffer, dataout); } -EXPORT_SYMBOL_GPL(iio_push_to_buffer); static void iio_buffer_demux_free(struct iio_buffer *buffer) { @@ -699,10 +810,26 @@ static void iio_buffer_demux_free(struct iio_buffer *buffer) } } -int iio_update_demux(struct iio_dev *indio_dev) + +int iio_push_to_buffers(struct iio_dev *indio_dev, unsigned char *data) +{ + int ret; + struct iio_buffer *buf; + + list_for_each_entry(buf, &indio_dev->buffer_list, buffer_list) { + ret = iio_push_to_buffer(buf, data); + if (ret < 0) + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(iio_push_to_buffers); + +static int iio_buffer_update_demux(struct iio_dev *indio_dev, + struct iio_buffer *buffer) { const struct iio_chan_spec *ch; - struct iio_buffer *buffer = indio_dev->buffer; int ret, in_ind = -1, out_ind, length; unsigned in_loc = 0, out_loc = 0; struct iio_demux_table *p; @@ -787,4 +914,23 @@ error_clear_mux_table: return ret; } + +int iio_update_demux(struct iio_dev *indio_dev) +{ + struct iio_buffer *buffer; + int ret; + + list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { + ret = iio_buffer_update_demux(indio_dev, buffer); + if (ret < 0) + goto error_clear_mux_table; + } + return 0; + +error_clear_mux_table: + list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) + iio_buffer_demux_free(buffer); + + return ret; +} EXPORT_SYMBOL_GPL(iio_update_demux); |