]> git.karo-electronics.de Git - karo-tx-linux.git/blobdiff - drivers/staging/iio/ring_sw.c
staging:iio: rationalization of different buffer implementation hooks.
[karo-tx-linux.git] / drivers / staging / iio / ring_sw.c
index d55757bb5fd9f872613c81aa405ac63f5944d7af..35896cbb07d96fc81ba91cbfff89214b6f157f1d 100644 (file)
 #include "ring_sw.h"
 #include "trigger.h"
 
+/**
+ * struct iio_sw_ring_buffer - software ring buffer
+ * @buf:               generic ring buffer elements
+ * @data:              the ring buffer memory
+ * @read_p:            read pointer (oldest available)
+ * @write_p:           write pointer
+ * @last_written_p:    read pointer (newest available)
+ * @half_p:            half buffer length behind write_p (event generation)
+ * @use_count:         reference count to prevent resizing when in use
+ * @update_needed:     flag to indicated change in size requested
+ * @use_lock:          lock to prevent change in size when in use
+ *
+ * Note that the first element of all ring buffers must be a
+ * struct iio_ring_buffer.
+**/
+struct iio_sw_ring_buffer {
+       struct iio_ring_buffer  buf;
+       unsigned char           *data;
+       unsigned char           *read_p;
+       unsigned char           *write_p;
+       unsigned char           *last_written_p;
+       /* used to act as a point at which to signal an event */
+       unsigned char           *half_p;
+       int                     use_count;
+       int                     update_needed;
+       spinlock_t              use_lock;
+};
+
+#define iio_to_sw_ring(r) container_of(r, struct iio_sw_ring_buffer, buf)
+
 static inline int __iio_allocate_sw_ring_buffer(struct iio_sw_ring_buffer *ring,
                                                int bytes_per_datum, int length)
 {
@@ -41,23 +71,21 @@ static inline void __iio_free_sw_ring_buffer(struct iio_sw_ring_buffer *ring)
        kfree(ring->data);
 }
 
-void iio_mark_sw_rb_in_use(struct iio_ring_buffer *r)
+static void iio_mark_sw_rb_in_use(struct iio_ring_buffer *r)
 {
        struct iio_sw_ring_buffer *ring = iio_to_sw_ring(r);
        spin_lock(&ring->use_lock);
        ring->use_count++;
        spin_unlock(&ring->use_lock);
 }
-EXPORT_SYMBOL(iio_mark_sw_rb_in_use);
 
-void iio_unmark_sw_rb_in_use(struct iio_ring_buffer *r)
+static void iio_unmark_sw_rb_in_use(struct iio_ring_buffer *r)
 {
        struct iio_sw_ring_buffer *ring = iio_to_sw_ring(r);
        spin_lock(&ring->use_lock);
        ring->use_count--;
        spin_unlock(&ring->use_lock);
 }
-EXPORT_SYMBOL(iio_unmark_sw_rb_in_use);
 
 
 /* Ring buffer related functionality */
@@ -138,8 +166,8 @@ static int iio_store_to_sw_ring(struct iio_sw_ring_buffer *ring,
        return ret;
 }
 
-int iio_read_first_n_sw_rb(struct iio_ring_buffer *r,
-                          size_t n, char __user *buf)
+static int iio_read_first_n_sw_rb(struct iio_ring_buffer *r,
+                                 size_t n, char __user *buf)
 {
        struct iio_sw_ring_buffer *ring = iio_to_sw_ring(r);
 
@@ -268,14 +296,14 @@ error_ret:
 
        return ret;
 }
-EXPORT_SYMBOL(iio_read_first_n_sw_rb);
 
-int iio_store_to_sw_rb(struct iio_ring_buffer *r, u8 *data, s64 timestamp)
+static int iio_store_to_sw_rb(struct iio_ring_buffer *r,
+                             u8 *data,
+                             s64 timestamp)
 {
        struct iio_sw_ring_buffer *ring = iio_to_sw_ring(r);
        return iio_store_to_sw_ring(ring, data, timestamp);
 }
-EXPORT_SYMBOL(iio_store_to_sw_rb);
 
 static int iio_read_last_from_sw_ring(struct iio_sw_ring_buffer *ring,
                                      unsigned char *data)
@@ -299,14 +327,13 @@ again:
        return 0;
 }
 
-int iio_read_last_from_sw_rb(struct iio_ring_buffer *r,
+static int iio_read_last_from_sw_rb(struct iio_ring_buffer *r,
                             unsigned char *data)
 {
        return iio_read_last_from_sw_ring(iio_to_sw_ring(r), data);
 }
-EXPORT_SYMBOL(iio_read_last_from_sw_rb);
 
-int iio_request_update_sw_rb(struct iio_ring_buffer *r)
+static int iio_request_update_sw_rb(struct iio_ring_buffer *r)
 {
        int ret = 0;
        struct iio_sw_ring_buffer *ring = iio_to_sw_ring(r);
@@ -326,50 +353,44 @@ error_ret:
        spin_unlock(&ring->use_lock);
        return ret;
 }
-EXPORT_SYMBOL(iio_request_update_sw_rb);
 
-int iio_get_bytes_per_datum_sw_rb(struct iio_ring_buffer *r)
+static int iio_get_bytes_per_datum_sw_rb(struct iio_ring_buffer *r)
 {
        struct iio_sw_ring_buffer *ring = iio_to_sw_ring(r);
        return ring->buf.bytes_per_datum;
 }
-EXPORT_SYMBOL(iio_get_bytes_per_datum_sw_rb);
 
-int iio_set_bytes_per_datum_sw_rb(struct iio_ring_buffer *r, size_t bpd)
+static int iio_set_bytes_per_datum_sw_rb(struct iio_ring_buffer *r, size_t bpd)
 {
        if (r->bytes_per_datum != bpd) {
                r->bytes_per_datum = bpd;
-               if (r->access.mark_param_change)
-                       r->access.mark_param_change(r);
+               if (r->access->mark_param_change)
+                       r->access->mark_param_change(r);
        }
        return 0;
 }
-EXPORT_SYMBOL(iio_set_bytes_per_datum_sw_rb);
 
-int iio_get_length_sw_rb(struct iio_ring_buffer *r)
+static int iio_get_length_sw_rb(struct iio_ring_buffer *r)
 {
        return r->length;
 }
-EXPORT_SYMBOL(iio_get_length_sw_rb);
 
-int iio_set_length_sw_rb(struct iio_ring_buffer *r, int length)
+static int iio_set_length_sw_rb(struct iio_ring_buffer *r, int length)
 {
        if (r->length != length) {
                r->length = length;
-               if (r->access.mark_param_change)
-                       r->access.mark_param_change(r);
+               if (r->access->mark_param_change)
+                       r->access->mark_param_change(r);
        }
        return 0;
 }
-EXPORT_SYMBOL(iio_set_length_sw_rb);
 
-int iio_mark_update_needed_sw_rb(struct iio_ring_buffer *r)
+static int iio_mark_update_needed_sw_rb(struct iio_ring_buffer *r)
 {
        struct iio_sw_ring_buffer *ring = iio_to_sw_ring(r);
        ring->update_needed = true;
        return 0;
 }
-EXPORT_SYMBOL(iio_mark_update_needed_sw_rb);
 
 static void iio_sw_rb_release(struct device *dev)
 {
@@ -412,6 +433,7 @@ struct iio_ring_buffer *iio_sw_rb_allocate(struct iio_dev *indio_dev)
        ring = kzalloc(sizeof *ring, GFP_KERNEL);
        if (!ring)
                return NULL;
+       ring->update_needed = true;
        buf = &ring->buf;
        iio_ring_buffer_init(buf, indio_dev);
        __iio_init_sw_ring_buffer(ring);
@@ -430,36 +452,11 @@ void iio_sw_rb_free(struct iio_ring_buffer *r)
 }
 EXPORT_SYMBOL(iio_sw_rb_free);
 
-int iio_sw_ring_preenable(struct iio_dev *indio_dev)
-{
-       struct iio_ring_buffer *ring = indio_dev->ring;
-       size_t size;
-       dev_dbg(&indio_dev->dev, "%s\n", __func__);
-       /* Check if there are any scan elements enabled, if not fail*/
-       if (!(ring->scan_count || ring->scan_timestamp))
-               return -EINVAL;
-       if (ring->scan_timestamp)
-               if (ring->scan_count)
-                       /* Timestamp (aligned to s64) and data */
-                       size = (((ring->scan_count * ring->bpe)
-                                       + sizeof(s64) - 1)
-                               & ~(sizeof(s64) - 1))
-                               + sizeof(s64);
-               else /* Timestamp only  */
-                       size = sizeof(s64);
-       else /* Data only */
-               size = ring->scan_count * ring->bpe;
-       ring->access.set_bytes_per_datum(ring, size);
-
-       return 0;
-}
-EXPORT_SYMBOL(iio_sw_ring_preenable);
-
 void iio_sw_trigger_to_ring(struct iio_sw_ring_helper_state *st)
 {
        struct iio_ring_buffer *ring = st->indio_dev->ring;
        int len = 0;
-       size_t datasize = ring->access.get_bytes_per_datum(ring);
+       size_t datasize = ring->access->get_bytes_per_datum(ring);
        char *data = kmalloc(datasize, GFP_KERNEL);
 
        if (data == NULL) {
@@ -476,7 +473,7 @@ void iio_sw_trigger_to_ring(struct iio_sw_ring_helper_state *st)
                *(s64 *)(((phys_addr_t)data + len
                                + sizeof(s64) - 1) & ~(sizeof(s64) - 1))
                        = st->last_timestamp;
-       ring->access.store_to(ring,
+       ring->access->store_to(ring,
                        (u8 *)data,
                        st->last_timestamp);
 
@@ -504,5 +501,20 @@ void iio_sw_poll_func_th(struct iio_dev *indio_dev, s64 time)
 }
 EXPORT_SYMBOL(iio_sw_poll_func_th);
 
+const struct iio_ring_access_funcs ring_sw_access_funcs = {
+       .mark_in_use = &iio_mark_sw_rb_in_use,
+       .unmark_in_use = &iio_unmark_sw_rb_in_use,
+       .store_to = &iio_store_to_sw_rb,
+       .read_last = &iio_read_last_from_sw_rb,
+       .read_first_n = &iio_read_first_n_sw_rb,
+       .mark_param_change = &iio_mark_update_needed_sw_rb,
+       .request_update = &iio_request_update_sw_rb,
+       .get_bytes_per_datum = &iio_get_bytes_per_datum_sw_rb,
+       .set_bytes_per_datum = &iio_set_bytes_per_datum_sw_rb,
+       .get_length = &iio_get_length_sw_rb,
+       .set_length = &iio_set_length_sw_rb,
+};
+EXPORT_SYMBOL(ring_sw_access_funcs);
+
 MODULE_DESCRIPTION("Industrialio I/O software ring buffer");
 MODULE_LICENSE("GPL");