diff options
Diffstat (limited to 'drivers/iio/industrialio-buffer.c')
| -rw-r--r-- | drivers/iio/industrialio-buffer.c | 242 |
1 files changed, 166 insertions, 76 deletions
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 2db7dcd826b9..7f9152c3c4d3 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -20,6 +20,7 @@ #include <linux/cdev.h> #include <linux/slab.h> #include <linux/poll.h> +#include <linux/sched.h> #include <linux/iio/iio.h> #include "iio_core.h" @@ -31,16 +32,9 @@ 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) +static bool iio_buffer_is_active(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; + return !list_empty(&buf->buffer_list); } /** @@ -55,6 +49,9 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf, struct iio_dev *indio_dev = filp->private_data; struct iio_buffer *rb = indio_dev->buffer; + if (!indio_dev->info) + return -ENODEV; + if (!rb || !rb->access->read_first_n) return -EINVAL; return rb->access->read_first_n(rb, n, buf); @@ -69,6 +66,9 @@ unsigned int iio_buffer_poll(struct file *filp, struct iio_dev *indio_dev = filp->private_data; struct iio_buffer *rb = indio_dev->buffer; + if (!indio_dev->info) + return -ENODEV; + poll_wait(filp, &rb->pollq, wait); if (rb->stufftoread) return POLLIN | POLLRDNORM; @@ -76,10 +76,27 @@ unsigned int iio_buffer_poll(struct file *filp, return 0; } +/** + * iio_buffer_wakeup_poll - Wakes up the buffer waitqueue + * @indio_dev: The IIO device + * + * Wakes up the event waitqueue used for poll(). Should usually + * be called when the device is unregistered. + */ +void iio_buffer_wakeup_poll(struct iio_dev *indio_dev) +{ + if (!indio_dev->buffer) + return; + + wake_up(&indio_dev->buffer->pollq); +} + void iio_buffer_init(struct iio_buffer *buffer) { INIT_LIST_HEAD(&buffer->demux_list); + INIT_LIST_HEAD(&buffer->buffer_list); init_waitqueue_head(&buffer->pollq); + kref_init(&buffer->ref); } EXPORT_SYMBOL(iio_buffer_init); @@ -146,7 +163,7 @@ static ssize_t iio_scan_el_store(struct device *dev, if (ret < 0) return ret; mutex_lock(&indio_dev->mlock); - if (iio_buffer_is_active(indio_dev, indio_dev->buffer)) { + if (iio_buffer_is_active(indio_dev->buffer)) { ret = -EBUSY; goto error_ret; } @@ -192,7 +209,7 @@ static ssize_t iio_scan_el_ts_store(struct device *dev, return ret; mutex_lock(&indio_dev->mlock); - if (iio_buffer_is_active(indio_dev, indio_dev->buffer)) { + if (iio_buffer_is_active(indio_dev->buffer)) { ret = -EBUSY; goto error_ret; } @@ -214,7 +231,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev, &iio_show_scan_index, NULL, 0, - 0, + IIO_SEPARATE, &indio_dev->dev, &buffer->scan_el_dev_attr_list); if (ret) @@ -249,29 +266,14 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev, 0, &indio_dev->dev, &buffer->scan_el_dev_attr_list); + if (ret) + goto error_ret; attrcount++; ret = attrcount; error_ret: return ret; } -static void iio_buffer_remove_and_free_scan_dev_attr(struct iio_dev *indio_dev, - struct iio_dev_attr *p) -{ - kfree(p->dev_attr.attr.name); - kfree(p); -} - -static void __iio_buffer_attr_cleanup(struct iio_dev *indio_dev) -{ - struct iio_dev_attr *p, *n; - struct iio_buffer *buffer = indio_dev->buffer; - - list_for_each_entry_safe(p, n, - &buffer->scan_el_dev_attr_list, l) - iio_buffer_remove_and_free_scan_dev_attr(indio_dev, p); -} - static const char * const iio_scan_elements_group_name = "scan_elements"; int iio_buffer_register(struct iio_dev *indio_dev, @@ -348,7 +350,7 @@ int iio_buffer_register(struct iio_dev *indio_dev, error_free_scan_mask: kfree(buffer->scan_mask); error_cleanup_dynamic: - __iio_buffer_attr_cleanup(indio_dev); + iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list); return ret; } @@ -358,7 +360,7 @@ void iio_buffer_unregister(struct iio_dev *indio_dev) { kfree(indio_dev->buffer->scan_mask); kfree(indio_dev->buffer->scan_el_group.attrs); - __iio_buffer_attr_cleanup(indio_dev); + iio_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list); } EXPORT_SYMBOL(iio_buffer_unregister); @@ -396,7 +398,7 @@ ssize_t iio_buffer_write_length(struct device *dev, return len; mutex_lock(&indio_dev->mlock); - if (iio_buffer_is_active(indio_dev, indio_dev->buffer)) { + if (iio_buffer_is_active(indio_dev->buffer)) { ret = -EBUSY; } else { if (buffer->access->set_length) @@ -414,13 +416,11 @@ ssize_t iio_buffer_show_enable(struct device *dev, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); - return sprintf(buf, "%d\n", - iio_buffer_is_active(indio_dev, - indio_dev->buffer)); + return sprintf(buf, "%d\n", iio_buffer_is_active(indio_dev->buffer)); } EXPORT_SYMBOL(iio_buffer_show_enable); -/* note NULL used as error indicator as it doesn't make sense. */ +/* Note NULL used as error indicator as it doesn't make sense. */ static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks, unsigned int masklength, const unsigned long *mask) @@ -435,8 +435,8 @@ static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks, return NULL; } -static int iio_compute_scan_bytes(struct iio_dev *indio_dev, const long *mask, - bool timestamp) +static int iio_compute_scan_bytes(struct iio_dev *indio_dev, + const unsigned long *mask, bool timestamp) { const struct iio_chan_spec *ch; unsigned bytes = 0; @@ -460,6 +460,19 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev, const long *mask, return bytes; } +static void iio_buffer_activate(struct iio_dev *indio_dev, + struct iio_buffer *buffer) +{ + iio_buffer_get(buffer); + list_add(&buffer->buffer_list, &indio_dev->buffer_list); +} + +static void iio_buffer_deactivate(struct iio_buffer *buffer) +{ + list_del_init(&buffer->buffer_list); + iio_buffer_put(buffer); +} + void iio_disable_all_buffers(struct iio_dev *indio_dev) { struct iio_buffer *buffer, *_buffer; @@ -472,7 +485,7 @@ void iio_disable_all_buffers(struct iio_dev *indio_dev) list_for_each_entry_safe(buffer, _buffer, &indio_dev->buffer_list, buffer_list) - list_del_init(&buffer->buffer_list); + iio_buffer_deactivate(buffer); indio_dev->currentmode = INDIO_DIRECT_MODE; if (indio_dev->setup_ops->postdisable) @@ -482,7 +495,21 @@ void iio_disable_all_buffers(struct iio_dev *indio_dev) kfree(indio_dev->active_scan_mask); } -int iio_update_buffers(struct iio_dev *indio_dev, +static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev, + struct iio_buffer *buffer) +{ + unsigned int bytes; + + if (!buffer->access->set_bytes_per_datum) + return; + + bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask, + buffer->scan_timestamp); + + buffer->access->set_bytes_per_datum(buffer, bytes); +} + +static int __iio_update_buffers(struct iio_dev *indio_dev, struct iio_buffer *insert_buffer, struct iio_buffer *remove_buffer) { @@ -512,9 +539,9 @@ int iio_update_buffers(struct iio_dev *indio_dev, indio_dev->active_scan_mask = NULL; if (remove_buffer) - list_del(&remove_buffer->buffer_list); + iio_buffer_deactivate(remove_buffer); if (insert_buffer) - list_add(&insert_buffer->buffer_list, &indio_dev->buffer_list); + iio_buffer_activate(indio_dev, insert_buffer); /* If no buffers in list, we are done */ if (list_empty(&indio_dev->buffer_list)) { @@ -524,7 +551,7 @@ int iio_update_buffers(struct iio_dev *indio_dev, return 0; } - /* What scan mask do we actually have ?*/ + /* What scan mask do we actually have? */ compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(long), GFP_KERNEL); if (compound_mask == NULL) { @@ -549,7 +576,7 @@ int iio_update_buffers(struct iio_dev *indio_dev, * Roll back. * Note can only occur when adding a buffer. */ - list_del(&insert_buffer->buffer_list); + iio_buffer_deactivate(insert_buffer); if (old_mask) { indio_dev->active_scan_mask = old_mask; success = -EINVAL; @@ -579,7 +606,8 @@ int iio_update_buffers(struct iio_dev *indio_dev, 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) + list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { + iio_buffer_update_bytes_per_datum(indio_dev, buffer); if (buffer->access->request_update) { ret = buffer->access->request_update(buffer); if (ret) { @@ -588,6 +616,7 @@ int iio_update_buffers(struct iio_dev *indio_dev, goto error_run_postdisable; } } + } if (indio_dev->info->update_scan_mode) { ret = indio_dev->info ->update_scan_mode(indio_dev, @@ -597,7 +626,7 @@ int iio_update_buffers(struct iio_dev *indio_dev, goto error_run_postdisable; } } - /* Definitely possible for devices to support both of these.*/ + /* 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"); @@ -608,7 +637,7 @@ int iio_update_buffers(struct iio_dev *indio_dev, 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 */ + } else { /* Should never be reached */ ret = -EINVAL; goto error_run_postdisable; } @@ -640,13 +669,50 @@ error_run_postdisable: error_remove_inserted: if (insert_buffer) - list_del(&insert_buffer->buffer_list); + iio_buffer_deactivate(insert_buffer); indio_dev->active_scan_mask = old_mask; kfree(compound_mask); error_ret: return ret; } + +int iio_update_buffers(struct iio_dev *indio_dev, + struct iio_buffer *insert_buffer, + struct iio_buffer *remove_buffer) +{ + int ret; + + if (insert_buffer == remove_buffer) + return 0; + + mutex_lock(&indio_dev->info_exist_lock); + mutex_lock(&indio_dev->mlock); + + if (insert_buffer && iio_buffer_is_active(insert_buffer)) + insert_buffer = NULL; + + if (remove_buffer && !iio_buffer_is_active(remove_buffer)) + remove_buffer = NULL; + + if (!insert_buffer && !remove_buffer) { + ret = 0; + goto out_unlock; + } + + if (indio_dev->info == NULL) { + ret = -ENODEV; + goto out_unlock; + } + + ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer); + +out_unlock: + mutex_unlock(&indio_dev->mlock); + mutex_unlock(&indio_dev->info_exist_lock); + + return ret; +} EXPORT_SYMBOL_GPL(iio_update_buffers); ssize_t iio_buffer_store_enable(struct device *dev, @@ -657,7 +723,6 @@ ssize_t iio_buffer_store_enable(struct device *dev, 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); @@ -667,16 +732,16 @@ ssize_t iio_buffer_store_enable(struct device *dev, mutex_lock(&indio_dev->mlock); /* Find out if it is in the list */ - inlist = iio_buffer_is_active(indio_dev, pbuf); + inlist = iio_buffer_is_active(indio_dev->buffer); /* Already in desired state */ if (inlist == requested_state) goto done; if (requested_state) - ret = iio_update_buffers(indio_dev, + ret = __iio_update_buffers(indio_dev, indio_dev->buffer, NULL); else - ret = iio_update_buffers(indio_dev, + ret = __iio_update_buffers(indio_dev, NULL, indio_dev->buffer); if (ret < 0) @@ -687,24 +752,6 @@ done: } 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); - /** * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected * @indio_dev: the iio device @@ -732,6 +779,7 @@ static bool iio_validate_scan_mask(struct iio_dev *indio_dev, /** * iio_scan_mask_set() - set particular bit in the scan mask + * @indio_dev: the iio device * @buffer: the buffer whose scan mask we are interested in * @bit: the bit to be set. * @@ -752,7 +800,7 @@ int iio_scan_mask_set(struct iio_dev *indio_dev, if (trialmask == NULL) return -ENOMEM; if (!indio_dev->masklength) { - WARN_ON("trying to set scanmask prior to registering buffer\n"); + WARN_ON("Trying to set scanmask prior to registering buffer\n"); goto err_invalid_mask; } bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength); @@ -807,8 +855,8 @@ struct iio_demux_table { struct list_head l; }; -static unsigned char *iio_demux(struct iio_buffer *buffer, - unsigned char *datain) +static const void *iio_demux(struct iio_buffer *buffer, + const void *datain) { struct iio_demux_table *t; @@ -821,9 +869,9 @@ static unsigned char *iio_demux(struct iio_buffer *buffer, return buffer->demux_bounce; } -static int iio_push_to_buffer(struct iio_buffer *buffer, unsigned char *data) +static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data) { - unsigned char *dataout = iio_demux(buffer, data); + const void *dataout = iio_demux(buffer, data); return buffer->access->store_to(buffer, dataout); } @@ -838,7 +886,7 @@ static void iio_buffer_demux_free(struct iio_buffer *buffer) } -int iio_push_to_buffers(struct iio_dev *indio_dev, unsigned char *data) +int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data) { int ret; struct iio_buffer *buf; @@ -961,3 +1009,45 @@ error_clear_mux_table: return ret; } EXPORT_SYMBOL_GPL(iio_update_demux); + +/** + * iio_buffer_release() - Free a buffer's resources + * @ref: Pointer to the kref embedded in the iio_buffer struct + * + * This function is called when the last reference to the buffer has been + * dropped. It will typically free all resources allocated by the buffer. Do not + * call this function manually, always use iio_buffer_put() when done using a + * buffer. + */ +static void iio_buffer_release(struct kref *ref) +{ + struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref); + + buffer->access->release(buffer); +} + +/** + * iio_buffer_get() - Grab a reference to the buffer + * @buffer: The buffer to grab a reference for, may be NULL + * + * Returns the pointer to the buffer that was passed into the function. + */ +struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer) +{ + if (buffer) + kref_get(&buffer->ref); + + return buffer; +} +EXPORT_SYMBOL_GPL(iio_buffer_get); + +/** + * iio_buffer_put() - Release the reference to the buffer + * @buffer: The buffer to release the reference for, may be NULL + */ +void iio_buffer_put(struct iio_buffer *buffer) +{ + if (buffer) + kref_put(&buffer->ref, iio_buffer_release); +} +EXPORT_SYMBOL_GPL(iio_buffer_put); |