am7xxx: clarify a comment about copying data in send_data_async()
[libam7xxx.git] / src / am7xxx.c
index b581718..3ba56f3 100644 (file)
@@ -1,6 +1,6 @@
 /* am7xxx - communication with AM7xxx based USB Pico Projectors and DPFs
  *
 /* am7xxx - communication with AM7xxx based USB Pico Projectors and DPFs
  *
- * Copyright (C) 2012  Antonio Ospite <ospite@studenti.unina.it>
+ * Copyright (C) 2012-2014  Antonio Ospite <ao2@ao2.it>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
 #include <stdarg.h>
 #include <errno.h>
 #include <libusb.h>
 #include <stdarg.h>
 #include <errno.h>
 #include <libusb.h>
+#include <math.h>
 
 #include "am7xxx.h"
 #include "serialize.h"
 
 #include "am7xxx.h"
 #include "serialize.h"
+#include "tools.h"
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 
  * taken from: http://unixwiz.net/techtips/gnu-c-attributes.html)
  */
 #ifndef __GNUC__
  * taken from: http://unixwiz.net/techtips/gnu-c-attributes.html)
  */
 #ifndef __GNUC__
-#  define  __attribute__(x)  /*NOTHING*/
+#  define  __attribute__(x)  /* NOTHING */
+#endif
+
+/* Control shared library symbols visibility */
+#if defined _WIN32 || defined __CYGWIN__
+       #define AM7XXX_PUBLIC __declspec(dllexport)
+       #define AM7XXX_LOCAL
+#else
+       #if __GNUC__ >= 4
+               #define AM7XXX_PUBLIC __attribute__ ((visibility ("default")))
+               #define AM7XXX_LOCAL  __attribute__ ((visibility ("hidden")))
+       #else
+               #define AM7XXX_PUBLIC
+               #define AM7XXX_LOCAL
+       #endif
 #endif
 
 static void log_message(am7xxx_context *ctx,
 #endif
 
 static void log_message(am7xxx_context *ctx,
@@ -49,35 +65,97 @@ static void log_message(am7xxx_context *ctx,
 #define debug(ctx, ...)   log_message(ctx,  AM7XXX_LOG_DEBUG,   __func__, 0,        __VA_ARGS__)
 #define trace(ctx, ...)   log_message(ctx,  AM7XXX_LOG_TRACE,   NULL,     0,        __VA_ARGS__)
 
 #define debug(ctx, ...)   log_message(ctx,  AM7XXX_LOG_DEBUG,   __func__, 0,        __VA_ARGS__)
 #define trace(ctx, ...)   log_message(ctx,  AM7XXX_LOG_TRACE,   NULL,     0,        __VA_ARGS__)
 
+struct am7xxx_ops {
+       int (*set_power_mode)(am7xxx_device *dev, am7xxx_power_mode power);
+       int (*set_zoom_mode)(am7xxx_device *dev, am7xxx_zoom_mode zoom);
+};
+
 struct am7xxx_usb_device_descriptor {
        const char *name;
        uint16_t vendor_id;
        uint16_t product_id;
 struct am7xxx_usb_device_descriptor {
        const char *name;
        uint16_t vendor_id;
        uint16_t product_id;
+       uint8_t configuration;    /* The bConfigurationValue of the device */
+       uint8_t interface_number; /* The bInterfaceNumber of the device */
+       struct am7xxx_ops ops;
 };
 
 };
 
-static struct am7xxx_usb_device_descriptor supported_devices[] = {
+static int default_set_power_mode(am7xxx_device *dev, am7xxx_power_mode power);
+static int picopix_set_power_mode(am7xxx_device *dev, am7xxx_power_mode power);
+static int default_set_zoom_mode(am7xxx_device *dev, am7xxx_zoom_mode zoom);
+static int picopix_set_zoom_mode(am7xxx_device *dev, am7xxx_zoom_mode zoom);
+
+#define DEFAULT_OPS { \
+       .set_power_mode = default_set_power_mode, \
+       .set_zoom_mode = default_set_zoom_mode, \
+}
+
+static const struct am7xxx_usb_device_descriptor supported_devices[] = {
        {
                .name       = "Acer C110",
                .vendor_id  = 0x1de1,
                .product_id = 0xc101,
        {
                .name       = "Acer C110",
                .vendor_id  = 0x1de1,
                .product_id = 0xc101,
+               .configuration    = 2,
+               .interface_number = 0,
+               .ops = DEFAULT_OPS,
+       },
+       {
+               .name       = "Acer C112",
+               .vendor_id  = 0x1de1,
+               .product_id = 0x5501,
+               .configuration    = 2,
+               .interface_number = 0,
+               .ops = DEFAULT_OPS,
+       },
+       {
+               .name       ="Aiptek PocketCinema T25",
+               .vendor_id  = 0x08ca,
+               .product_id = 0x2144,
+               .configuration    = 2,
+               .interface_number = 0,
+               .ops = DEFAULT_OPS,
        },
        {
                .name       = "Philips/Sagemcom PicoPix 1020",
                .vendor_id  = 0x21e7,
                .product_id = 0x000e,
        },
        {
                .name       = "Philips/Sagemcom PicoPix 1020",
                .vendor_id  = 0x21e7,
                .product_id = 0x000e,
+               .configuration    = 2,
+               .interface_number = 0,
+               .ops = DEFAULT_OPS,
+       },
+       {
+               .name       = "Philips/Sagemcom PicoPix 2055",
+               .vendor_id  = 0x21e7,
+               .product_id = 0x0016,
+               .configuration    = 2,
+               .interface_number = 0,
+               .ops = {
+                       .set_power_mode = picopix_set_power_mode,
+                       .set_zoom_mode = picopix_set_zoom_mode,
+               },
+       },
+       {
+               .name       = "Philips/Sagemcom PicoPix 2330",
+               .vendor_id  = 0x21e7,
+               .product_id = 0x0019,
+               .configuration    = 1,
+               .interface_number = 0,
        },
 };
 
 /* The header size on the wire is known to be always 24 bytes, regardless of
        },
 };
 
 /* The header size on the wire is known to be always 24 bytes, regardless of
- * the memory configuration enforced by different architechtures or compilers
+ * the memory configuration enforced by different architectures or compilers
  * for struct am7xxx_header
  */
 #define AM7XXX_HEADER_WIRE_SIZE 24
 
 struct _am7xxx_device {
        libusb_device_handle *usb_device;
  * for struct am7xxx_header
  */
 #define AM7XXX_HEADER_WIRE_SIZE 24
 
 struct _am7xxx_device {
        libusb_device_handle *usb_device;
+       struct libusb_transfer *transfer;
+       int transfer_completed;
        uint8_t buffer[AM7XXX_HEADER_WIRE_SIZE];
        uint8_t buffer[AM7XXX_HEADER_WIRE_SIZE];
+       am7xxx_device_info *device_info;
        am7xxx_context *ctx;
        am7xxx_context *ctx;
+       const struct am7xxx_usb_device_descriptor *desc;
        am7xxx_device *next;
 };
 
        am7xxx_device *next;
 };
 
@@ -91,7 +169,12 @@ typedef enum {
        AM7XXX_PACKET_TYPE_DEVINFO = 0x01,
        AM7XXX_PACKET_TYPE_IMAGE   = 0x02,
        AM7XXX_PACKET_TYPE_POWER   = 0x04,
        AM7XXX_PACKET_TYPE_DEVINFO = 0x01,
        AM7XXX_PACKET_TYPE_IMAGE   = 0x02,
        AM7XXX_PACKET_TYPE_POWER   = 0x04,
-       AM7XXX_PACKET_TYPE_UNKNOWN = 0x05,
+       AM7XXX_PACKET_TYPE_ZOOM    = 0x05,
+       AM7XXX_PACKET_TYPE_PICOPIX_POWER_LOW    = 0x15,
+       AM7XXX_PACKET_TYPE_PICOPIX_POWER_MEDIUM = 0x16,
+       AM7XXX_PACKET_TYPE_PICOPIX_POWER_HIGH   = 0x17,
+       AM7XXX_PACKET_TYPE_PICOPIX_ENABLE_TI    = 0x18,
+       AM7XXX_PACKET_TYPE_PICOPIX_DISABLE_TI   = 0x19,
 } am7xxx_packet_type;
 
 struct am7xxx_generic_header {
 } am7xxx_packet_type;
 
 struct am7xxx_generic_header {
@@ -121,6 +204,11 @@ struct am7xxx_power_header {
        uint32_t bit0;
 };
 
        uint32_t bit0;
 };
 
+struct am7xxx_zoom_header {
+       uint32_t bit1;
+       uint32_t bit0;
+};
+
 /*
  * Examples of packet headers:
  *
 /*
  * Examples of packet headers:
  *
@@ -131,9 +219,13 @@ struct am7xxx_power_header {
  * 04 00 00 00 00 0c ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  */
 
  * 04 00 00 00 00 0c ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  */
 
+/* Direction of the communication from the host point of view */
+#define AM7XXX_DIRECTION_OUT 0 /* host -> device */
+#define AM7XXX_DIRECTION_IN  1 /* host <- device */
+
 struct am7xxx_header {
        uint32_t packet_type;
 struct am7xxx_header {
        uint32_t packet_type;
-       uint8_t unknown0;
+       uint8_t direction;
        uint8_t header_data_len;
        uint8_t unknown2;
        uint8_t unknown3;
        uint8_t header_data_len;
        uint8_t unknown2;
        uint8_t unknown3;
@@ -142,11 +234,24 @@ struct am7xxx_header {
                struct am7xxx_devinfo_header devinfo;
                struct am7xxx_image_header image;
                struct am7xxx_power_header power;
                struct am7xxx_devinfo_header devinfo;
                struct am7xxx_image_header image;
                struct am7xxx_power_header power;
+               struct am7xxx_zoom_header zoom;
        } header_data;
 };
 
 
 #ifdef DEBUG
        } header_data;
 };
 
 
 #ifdef DEBUG
+static void debug_dump_generic_header(am7xxx_context *ctx, struct am7xxx_generic_header *g)
+{
+       if (ctx == NULL || g == NULL)
+               return;
+
+       debug(ctx, "Generic header:\n");
+       debug(ctx, "\tfield0:  0x%08x (%u)\n", g->field0, g->field0);
+       debug(ctx, "\tfield1:  0x%08x (%u)\n", g->field1, g->field1);
+       debug(ctx, "\tfield2:  0x%08x (%u)\n", g->field2, g->field2);
+       debug(ctx, "\tfield3:  0x%08x (%u)\n", g->field3, g->field3);
+}
+
 static void debug_dump_devinfo_header(am7xxx_context *ctx, struct am7xxx_devinfo_header *d)
 {
        if (ctx == NULL || d == NULL)
 static void debug_dump_devinfo_header(am7xxx_context *ctx, struct am7xxx_devinfo_header *d)
 {
        if (ctx == NULL || d == NULL)
@@ -182,6 +287,16 @@ static void debug_dump_power_header(am7xxx_context *ctx, struct am7xxx_power_hea
        debug(ctx, "\tbit0: 0x%08x (%u)\n", p->bit0, p->bit0);
 }
 
        debug(ctx, "\tbit0: 0x%08x (%u)\n", p->bit0, p->bit0);
 }
 
+static void debug_dump_zoom_header(am7xxx_context *ctx, struct am7xxx_zoom_header *z)
+{
+       if (ctx == NULL || z == NULL)
+               return;
+
+       debug(ctx, "Zoom header:\n");
+       debug(ctx, "\tbit1: 0x%08x (%u)\n", z->bit1, z->bit1);
+       debug(ctx, "\tbit0: 0x%08x (%u)\n", z->bit0, z->bit0);
+}
+
 static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
 {
        if (ctx == NULL || h == NULL)
 static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
 {
        if (ctx == NULL || h == NULL)
@@ -189,7 +304,10 @@ static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
 
        debug(ctx, "BEGIN\n");
        debug(ctx, "packet_type:     0x%08x (%u)\n", h->packet_type, h->packet_type);
 
        debug(ctx, "BEGIN\n");
        debug(ctx, "packet_type:     0x%08x (%u)\n", h->packet_type, h->packet_type);
-       debug(ctx, "unknown0:        0x%02hhx (%hhu)\n", h->unknown0, h->unknown0);
+       debug(ctx, "direction:       0x%02hhx (%hhu) (%s)\n", h->direction, h->direction,
+             h->direction == AM7XXX_DIRECTION_IN ? "IN" :
+             h->direction == AM7XXX_DIRECTION_OUT ? "OUT" :
+             "UNKNOWN");
        debug(ctx, "header_data_len: 0x%02hhx (%hhu)\n", h->header_data_len, h->header_data_len);
        debug(ctx, "unknown2:        0x%02hhx (%hhu)\n", h->unknown2, h->unknown2);
        debug(ctx, "unknown3:        0x%02hhx (%hhu)\n", h->unknown3, h->unknown3);
        debug(ctx, "header_data_len: 0x%02hhx (%hhu)\n", h->header_data_len, h->header_data_len);
        debug(ctx, "unknown2:        0x%02hhx (%hhu)\n", h->unknown2, h->unknown2);
        debug(ctx, "unknown3:        0x%02hhx (%hhu)\n", h->unknown3, h->unknown3);
@@ -207,8 +325,13 @@ static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
                debug_dump_power_header(ctx, &(h->header_data.power));
                break;
 
                debug_dump_power_header(ctx, &(h->header_data.power));
                break;
 
+       case AM7XXX_PACKET_TYPE_ZOOM:
+               debug_dump_zoom_header(ctx, &(h->header_data.zoom));
+               break;
+
        default:
        default:
-               debug(ctx, "Packet type not supported!\n");
+               debug(ctx, "Parsing data not supported for this packet type!\n");
+               debug_dump_generic_header(ctx, &(h->header_data.data));
                break;
        }
        debug(ctx, "END\n\n");
                break;
        }
        debug(ctx, "END\n\n");
@@ -244,6 +367,7 @@ static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
        (void)ctx;
        (void)h;
 }
        (void)ctx;
        (void)h;
 }
+
 static void trace_dump_buffer(am7xxx_context *ctx, const char *message,
                              uint8_t *buffer, unsigned int len)
 {
 static void trace_dump_buffer(am7xxx_context *ctx, const char *message,
                              uint8_t *buffer, unsigned int len)
 {
@@ -261,8 +385,8 @@ static int read_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
 
        ret = libusb_bulk_transfer(dev->usb_device, 0x81, buffer, len, &transferred, 0);
        if (ret != 0 || (unsigned int)transferred != len) {
 
        ret = libusb_bulk_transfer(dev->usb_device, 0x81, buffer, len, &transferred, 0);
        if (ret != 0 || (unsigned int)transferred != len) {
-               error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
-                     ret, transferred, len);
+               error(dev->ctx, "%s. Transferred: %d (expected %u)\n",
+                     libusb_error_name(ret), transferred, len);
                return ret;
        }
 
                return ret;
        }
 
@@ -278,22 +402,133 @@ static int send_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
 
        trace_dump_buffer(dev->ctx, "sending -->", buffer, len);
 
 
        trace_dump_buffer(dev->ctx, "sending -->", buffer, len);
 
-       ret = libusb_bulk_transfer(dev->usb_device, 1, buffer, len, &transferred, 0);
+       ret = libusb_bulk_transfer(dev->usb_device, 0x1, buffer, len, &transferred, 0);
        if (ret != 0 || (unsigned int)transferred != len) {
        if (ret != 0 || (unsigned int)transferred != len) {
-               error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
-                     ret, transferred, len);
+               error(dev->ctx, "%s. Transferred: %d (expected %u)\n",
+                     libusb_error_name(ret), transferred, len);
                return ret;
        }
 
        return 0;
 }
 
                return ret;
        }
 
        return 0;
 }
 
+static void send_data_async_complete_cb(struct libusb_transfer *transfer)
+{
+       am7xxx_device *dev = (am7xxx_device *)(transfer->user_data);
+       int *completed = &(dev->transfer_completed);
+       int transferred = transfer->actual_length;
+       int ret;
+
+       if (transferred != transfer->length) {
+               error(dev->ctx, "transferred: %d (expected %u)\n",
+                     transferred, transfer->length);
+       }
+
+       switch (transfer->status) {
+       case LIBUSB_TRANSFER_COMPLETED:
+               ret = 0;
+               break;
+       case LIBUSB_TRANSFER_TIMED_OUT:
+               ret = LIBUSB_ERROR_TIMEOUT;
+               break;
+       case LIBUSB_TRANSFER_STALL:
+               ret = LIBUSB_ERROR_PIPE;
+               break;
+       case LIBUSB_TRANSFER_OVERFLOW:
+               ret = LIBUSB_ERROR_OVERFLOW;
+               break;
+       case LIBUSB_TRANSFER_NO_DEVICE:
+               ret = LIBUSB_ERROR_NO_DEVICE;
+               break;
+       case LIBUSB_TRANSFER_ERROR:
+       case LIBUSB_TRANSFER_CANCELLED:
+               ret = LIBUSB_ERROR_IO;
+               break;
+       default:
+               error(dev->ctx, "unrecognised status code %d", transfer->status);
+               ret = LIBUSB_ERROR_OTHER;
+       }
+
+       if (ret < 0)
+               error(dev->ctx, "libusb transfer failed: %s",
+                     libusb_error_name(ret));
+
+       libusb_free_transfer(transfer);
+       transfer = NULL;
+
+       *completed = 1;
+}
+
+static inline void wait_for_trasfer_completed(am7xxx_device *dev)
+{
+       while (!dev->transfer_completed) {
+               int ret = libusb_handle_events_completed(dev->ctx->usb_context,
+                                                        &(dev->transfer_completed));
+               if (ret < 0) {
+                       if (ret == LIBUSB_ERROR_INTERRUPTED)
+                               continue;
+                       error(dev->ctx, "libusb_handle_events failed: %s, cancelling transfer and retrying",
+                             libusb_error_name(ret));
+                       libusb_cancel_transfer(dev->transfer);
+                       continue;
+               }
+       }
+}
+
+static int send_data_async(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
+{
+       int ret;
+       uint8_t *transfer_buffer;
+
+       dev->transfer = libusb_alloc_transfer(0);
+       if (dev->transfer == NULL) {
+               error(dev->ctx, "cannot allocate transfer (%s)\n",
+                     strerror(errno));
+               return -ENOMEM;
+       }
+
+       /* Make a copy of the buffer so the caller can safely reuse it just
+        * after libusb_submit_transfer() has returned. This technique
+        * requires more dynamic allocations compared to a proper
+        * double-buffering approach but it takes a lot less code. */
+       transfer_buffer = malloc(len);
+       if (transfer_buffer == NULL) {
+               error(dev->ctx, "cannot allocate transfer buffer (%s)\n",
+                     strerror(errno));
+               ret = -ENOMEM;
+               goto err;
+       }
+       memcpy(transfer_buffer, buffer, len);
+
+       dev->transfer->flags |= LIBUSB_TRANSFER_FREE_BUFFER;
+       libusb_fill_bulk_transfer(dev->transfer, dev->usb_device, 0x1,
+                                 transfer_buffer, len,
+                                 send_data_async_complete_cb, dev, 0);
+
+       /* wait for the previous transfer to complete */
+       wait_for_trasfer_completed(dev);
+
+       trace_dump_buffer(dev->ctx, "sending -->", buffer, len);
+
+       dev->transfer_completed = 0;
+       ret = libusb_submit_transfer(dev->transfer);
+       if (ret < 0)
+               goto err;
+
+       return 0;
+
+err:
+       libusb_free_transfer(dev->transfer);
+       dev->transfer = NULL;
+       return ret;
+}
+
 static void serialize_header(struct am7xxx_header *h, uint8_t *buffer)
 {
        uint8_t **buffer_iterator = &buffer;
 
        put_le32(h->packet_type, buffer_iterator);
 static void serialize_header(struct am7xxx_header *h, uint8_t *buffer)
 {
        uint8_t **buffer_iterator = &buffer;
 
        put_le32(h->packet_type, buffer_iterator);
-       put_8(h->unknown0, buffer_iterator);
+       put_8(h->direction, buffer_iterator);
        put_8(h->header_data_len, buffer_iterator);
        put_8(h->unknown2, buffer_iterator);
        put_8(h->unknown3, buffer_iterator);
        put_8(h->header_data_len, buffer_iterator);
        put_8(h->unknown2, buffer_iterator);
        put_8(h->unknown3, buffer_iterator);
@@ -308,7 +543,7 @@ static void unserialize_header(uint8_t *buffer, struct am7xxx_header *h)
        uint8_t **buffer_iterator = &buffer;
 
        h->packet_type = get_le32(buffer_iterator);
        uint8_t **buffer_iterator = &buffer;
 
        h->packet_type = get_le32(buffer_iterator);
-       h->unknown0 = get_8(buffer_iterator);
+       h->direction = get_8(buffer_iterator);
        h->header_data_len = get_8(buffer_iterator);
        h->unknown2 = get_8(buffer_iterator);
        h->unknown3 = get_8(buffer_iterator);
        h->header_data_len = get_8(buffer_iterator);
        h->unknown2 = get_8(buffer_iterator);
        h->unknown3 = get_8(buffer_iterator);
@@ -328,9 +563,16 @@ static int read_header(am7xxx_device *dev, struct am7xxx_header *h)
 
        unserialize_header(dev->buffer, h);
 
 
        unserialize_header(dev->buffer, h);
 
-       debug_dump_header(dev->ctx, h);
+       if (h->direction == AM7XXX_DIRECTION_IN) {
+               ret = 0;
+       } else {
+               error(dev->ctx,
+                     "Expected an AM7XXX_DIRECTION_IN packet, got one with direction = %d. Weird!\n",
+                     h->direction);
+               ret = -EINVAL;
+       }
 
 
-       ret = 0;
+       debug_dump_header(dev->ctx, h);
 
 out:
        return ret;
 
 out:
        return ret;
@@ -342,7 +584,13 @@ static int send_header(am7xxx_device *dev, struct am7xxx_header *h)
 
        debug_dump_header(dev->ctx, h);
 
 
        debug_dump_header(dev->ctx, h);
 
+       /* For symmetry with read_header() we should check here for
+        * h->direction == AM7XXX_DIRECTION_OUT but we just ensure that in all
+        * the callers and save some cycles here.
+        */
+
        serialize_header(h, dev->buffer);
        serialize_header(h, dev->buffer);
+
        ret = send_data(dev, dev->buffer, AM7XXX_HEADER_WIRE_SIZE);
        if (ret < 0)
                error(dev->ctx, "failed to send data\n");
        ret = send_data(dev, dev->buffer, AM7XXX_HEADER_WIRE_SIZE);
        if (ret < 0)
                error(dev->ctx, "failed to send data\n");
@@ -350,6 +598,28 @@ static int send_header(am7xxx_device *dev, struct am7xxx_header *h)
        return ret;
 }
 
        return ret;
 }
 
+static int send_command(am7xxx_device *dev, am7xxx_packet_type type)
+{
+       struct am7xxx_header h = {
+               .packet_type     = type,
+               .direction       = AM7XXX_DIRECTION_OUT,
+               .header_data_len = 0x00,
+               .unknown2        = 0x3e,
+               .unknown3        = 0x10,
+               .header_data = {
+                       .data = {
+                               .field0 = 0,
+                               .field1 = 0,
+                               .field2 = 0,
+                               .field3 = 0,
+                       },
+               },
+       };
+
+       return send_header(dev, &h);
+}
+
+
 /* When level == AM7XXX_LOG_FATAL do not check the log_level from the context
  * and print the message unconditionally, this makes it possible to print
  * fatal messages even early on initialization, before the context has been
 /* When level == AM7XXX_LOG_FATAL do not check the log_level from the context
  * and print the message unconditionally, this makes it possible to print
  * fatal messages even early on initialization, before the context has been
@@ -379,7 +649,8 @@ static void log_message(am7xxx_context *ctx,
        return;
 }
 
        return;
 }
 
-static am7xxx_device *add_new_device(am7xxx_context *ctx)
+static am7xxx_device *add_new_device(am7xxx_context *ctx,
+                                    const struct am7xxx_usb_device_descriptor *desc)
 {
        am7xxx_device **devices_list;
        am7xxx_device *new_device;
 {
        am7xxx_device **devices_list;
        am7xxx_device *new_device;
@@ -389,8 +660,6 @@ static am7xxx_device *add_new_device(am7xxx_context *ctx)
                return NULL;
        }
 
                return NULL;
        }
 
-       devices_list = &(ctx->devices_list);
-
        new_device = malloc(sizeof(*new_device));
        if (new_device == NULL) {
                fatal("cannot allocate a new device (%s)\n", strerror(errno));
        new_device = malloc(sizeof(*new_device));
        if (new_device == NULL) {
                fatal("cannot allocate a new device (%s)\n", strerror(errno));
@@ -399,6 +668,10 @@ static am7xxx_device *add_new_device(am7xxx_context *ctx)
        memset(new_device, 0, sizeof(*new_device));
 
        new_device->ctx = ctx;
        memset(new_device, 0, sizeof(*new_device));
 
        new_device->ctx = ctx;
+       new_device->desc = desc;
+       new_device->transfer_completed = 1;
+
+       devices_list = &(ctx->devices_list);
 
        if (*devices_list == NULL) {
                *devices_list = new_device;
 
        if (*devices_list == NULL) {
                *devices_list = new_device;
@@ -429,6 +702,109 @@ static am7xxx_device *find_device(am7xxx_context *ctx,
        return current;
 }
 
        return current;
 }
 
+static int open_device(am7xxx_context *ctx,
+                      unsigned int device_index,
+                      libusb_device *usb_dev,
+                      am7xxx_device **dev)
+{
+       int ret;
+       int current_configuration;
+
+       *dev = find_device(ctx, device_index);
+       if (*dev == NULL) {
+               ret = -ENODEV;
+               goto out;
+       }
+
+       /* the usb device has already been opened */
+       if ((*dev)->usb_device) {
+               debug(ctx, "(*dev)->usb_device already set\n");
+               ret = 1;
+               goto out;
+       }
+
+       ret = libusb_open(usb_dev, &((*dev)->usb_device));
+       if (ret < 0) {
+               debug(ctx, "libusb_open failed: %s\n", libusb_error_name(ret));
+               goto out;
+       }
+
+       /* XXX, the device is now open, if any of the calls below fail we need
+        * to close it again before bailing out.
+        */
+
+       current_configuration = -1;
+       ret = libusb_get_configuration((*dev)->usb_device,
+                                      &current_configuration);
+       if (ret < 0) {
+               debug(ctx, "libusb_get_configuration failed: %s\n",
+                     libusb_error_name(ret));
+               goto out_libusb_close;
+       }
+
+       if (current_configuration != (*dev)->desc->configuration) {
+               /*
+                * In principle kernel drivers bound to each interface should
+                * be detached before setting the configuration, but in
+                * practice this is not necessary for most devices.
+                *
+                * For example something like the following function would be
+                * called:
+                *      libusb_detach_all_kernel_drivers((*dev)->usb_device);
+                */
+               ret = libusb_set_configuration((*dev)->usb_device,
+                                              (*dev)->desc->configuration);
+               if (ret < 0) {
+                       debug(ctx, "libusb_set_configuration failed: %s\n",
+                             libusb_error_name(ret));
+                       debug(ctx, "Cannot set configuration %hhu\n",
+                             (*dev)->desc->configuration);
+                       goto out_libusb_close;
+               }
+       }
+
+       libusb_set_auto_detach_kernel_driver((*dev)->usb_device, 1);
+
+       ret = libusb_claim_interface((*dev)->usb_device,
+                                    (*dev)->desc->interface_number);
+       if (ret < 0) {
+               debug(ctx, "libusb_claim_interface failed: %s\n",
+                     libusb_error_name(ret));
+               debug(ctx, "Cannot claim interface %hhu\n",
+                     (*dev)->desc->interface_number);
+               goto out_libusb_close;
+       }
+
+       /* Checking that the configuration has not changed, as suggested in
+        * http://libusb.sourceforge.net/api-1.0/caveats.html
+        */
+       current_configuration = -1;
+       ret = libusb_get_configuration((*dev)->usb_device,
+                                      &current_configuration);
+       if (ret < 0) {
+               debug(ctx, "libusb_get_configuration after claim failed: %s\n",
+                     libusb_error_name(ret));
+               goto out_libusb_release_interface;
+       }
+
+       if (current_configuration != (*dev)->desc->configuration) {
+               debug(ctx, "libusb configuration changed (expected: %hhu, current: %hhu\n",
+                     (*dev)->desc->configuration, current_configuration);
+               ret = -EINVAL;
+               goto out_libusb_release_interface;
+       }
+out:
+       return ret;
+
+out_libusb_release_interface:
+       libusb_release_interface((*dev)->usb_device,
+                                (*dev)->desc->interface_number);
+out_libusb_close:
+       libusb_close((*dev)->usb_device);
+       (*dev)->usb_device = NULL;
+       return ret;
+}
+
 typedef enum {
        SCAN_OP_BUILD_DEVLIST,
        SCAN_OP_OPEN_DEVICE,
 typedef enum {
        SCAN_OP_BUILD_DEVLIST,
        SCAN_OP_OPEN_DEVICE,
@@ -438,13 +814,14 @@ typedef enum {
  * This is where the central logic of multi-device support is.
  *
  * When 'op' == SCAN_OP_BUILD_DEVLIST the parameters 'open_device_index' and
  * This is where the central logic of multi-device support is.
  *
  * When 'op' == SCAN_OP_BUILD_DEVLIST the parameters 'open_device_index' and
- * 'dev' are ignored; the function returns 0 on success and a negative value
+ * 'dev' are ignored; the function returns 0 on success or a negative value
  * on error.
  *
  * When 'op' == SCAN_OP_OPEN_DEVICE the function opens the supported USB
  * device with index 'open_device_index' and returns the correspondent
  * on error.
  *
  * When 'op' == SCAN_OP_OPEN_DEVICE the function opens the supported USB
  * device with index 'open_device_index' and returns the correspondent
- * am7xxx_device in the 'dev' parameter; the function returns 0 on success,
- * 1 if the device was already open and a negative value on error.
+ * am7xxx_device in the 'dev' parameter; the function returns the value from
+ * open_device(), which is 0 on success, 1 if the device was already open or
+ * a negative value on error.
  *
  * NOTES:
  * if scan_devices() fails when called with 'op' == SCAN_OP_BUILD_DEVLIST,
  *
  * NOTES:
  * if scan_devices() fails when called with 'op' == SCAN_OP_BUILD_DEVLIST,
@@ -454,8 +831,8 @@ typedef enum {
 static int scan_devices(am7xxx_context *ctx, scan_op op,
                        unsigned int open_device_index, am7xxx_device **dev)
 {
 static int scan_devices(am7xxx_context *ctx, scan_op op,
                        unsigned int open_device_index, am7xxx_device **dev)
 {
-       int num_devices;
-       libusb_device** list;
+       ssize_t num_devices;
+       libusb_device **list;
        unsigned int current_index;
        int i;
        int ret;
        unsigned int current_index;
        int i;
        int ret;
@@ -485,15 +862,15 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
                        continue;
 
                for (j = 0; j < ARRAY_SIZE(supported_devices); j++) {
                        continue;
 
                for (j = 0; j < ARRAY_SIZE(supported_devices); j++) {
-                       if (desc.idVendor == supported_devices[j].vendor_id
-                           && desc.idProduct == supported_devices[j].product_id) {
+                       if (desc.idVendor == supported_devices[j].vendor_id &&
+                           desc.idProduct == supported_devices[j].product_id) {
 
                                if (op == SCAN_OP_BUILD_DEVLIST) {
                                        am7xxx_device *new_device;
                                        info(ctx, "am7xxx device found, index: %d, name: %s\n",
                                             current_index,
                                             supported_devices[j].name);
 
                                if (op == SCAN_OP_BUILD_DEVLIST) {
                                        am7xxx_device *new_device;
                                        info(ctx, "am7xxx device found, index: %d, name: %s\n",
                                             current_index,
                                             supported_devices[j].name);
-                                       new_device = add_new_device(ctx);
+                                       new_device = add_new_device(ctx, &supported_devices[j]);
                                        if (new_device == NULL) {
                                                /* XXX, the caller may want
                                                 * to call am7xxx_shutdown() if
                                        if (new_device == NULL) {
                                                /* XXX, the caller may want
                                                 * to call am7xxx_shutdown() if
@@ -507,27 +884,16 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
                                } else if (op == SCAN_OP_OPEN_DEVICE &&
                                           current_index == open_device_index) {
 
                                } else if (op == SCAN_OP_OPEN_DEVICE &&
                                           current_index == open_device_index) {
 
-                                       *dev = find_device(ctx, open_device_index);
-                                       if (*dev == NULL) {
-                                               ret = -ENODEV;
-                                               goto out;
-                                       }
-
-                                       /* the usb device has already been opened */
-                                       if ((*dev)->usb_device) {
-                                               debug(ctx, "(*dev)->usb_device already set\n");
-                                               ret = 1;
-                                               goto out;
-                                       }
-
-                                       ret = libusb_open(list[i], &((*dev)->usb_device));
-                                       if (ret < 0) {
-                                               debug(ctx, "libusb_open failed\n");
-                                               goto out;
-                                       }
+                                       ret = open_device(ctx,
+                                                         open_device_index,
+                                                         list[i],
+                                                         dev);
+                                       if (ret < 0)
+                                               debug(ctx, "open_device failed\n");
 
 
-                                       libusb_set_configuration((*dev)->usb_device, 1);
-                                       libusb_claim_interface((*dev)->usb_device, 0);
+                                       /* exit the loop unconditionally after
+                                        * attempting to open the device
+                                        * requested by the user */
                                        goto out;
                                }
                                current_index++;
                                        goto out;
                                }
                                current_index++;
@@ -535,7 +901,8 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
                }
        }
 
                }
        }
 
-       /* if we made it up to here we didn't find any device to open */
+       /* if we made it up to here when op == SCAN_OP_OPEN_DEVICE,
+        * no devices to open had been found. */
        if (op == SCAN_OP_OPEN_DEVICE) {
                error(ctx, "Cannot find any device to open\n");
                ret = -ENODEV;
        if (op == SCAN_OP_OPEN_DEVICE) {
                error(ctx, "Cannot find any device to open\n");
                ret = -ENODEV;
@@ -549,9 +916,167 @@ out:
        return ret;
 }
 
        return ret;
 }
 
-int am7xxx_init(am7xxx_context **ctx)
+/* Device specific operations */
+
+static int default_set_power_mode(am7xxx_device *dev, am7xxx_power_mode power)
 {
 {
-       int ret = 0;
+       int ret;
+       struct am7xxx_header h = {
+               .packet_type     = AM7XXX_PACKET_TYPE_POWER,
+               .direction       = AM7XXX_DIRECTION_OUT,
+               .header_data_len = sizeof(struct am7xxx_power_header),
+               .unknown2        = 0x3e,
+               .unknown3        = 0x10,
+       };
+
+       switch(power) {
+       case AM7XXX_POWER_OFF:
+               h.header_data.power.bit2 = 0;
+               h.header_data.power.bit1 = 0;
+               h.header_data.power.bit0 = 0;
+               break;
+
+       case AM7XXX_POWER_LOW:
+               h.header_data.power.bit2 = 0;
+               h.header_data.power.bit1 = 0;
+               h.header_data.power.bit0 = 1;
+               break;
+
+       case AM7XXX_POWER_MIDDLE:
+               h.header_data.power.bit2 = 0;
+               h.header_data.power.bit1 = 1;
+               h.header_data.power.bit0 = 0;
+               break;
+
+       case AM7XXX_POWER_HIGH:
+               h.header_data.power.bit2 = 0;
+               h.header_data.power.bit1 = 1;
+               h.header_data.power.bit0 = 1;
+               break;
+
+       case AM7XXX_POWER_TURBO:
+               h.header_data.power.bit2 = 1;
+               h.header_data.power.bit1 = 0;
+               h.header_data.power.bit0 = 0;
+               break;
+
+       default:
+               error(dev->ctx, "Unsupported power mode.\n");
+               return -EINVAL;
+       };
+
+       ret = send_header(dev, &h);
+       if (ret < 0)
+               return ret;
+
+       return 0;
+}
+
+static int picopix_set_power_mode(am7xxx_device *dev, am7xxx_power_mode power)
+{
+       switch(power) {
+       case AM7XXX_POWER_LOW:
+               return send_command(dev, AM7XXX_PACKET_TYPE_PICOPIX_POWER_LOW);
+
+       case AM7XXX_POWER_MIDDLE:
+               return send_command(dev, AM7XXX_PACKET_TYPE_PICOPIX_POWER_MEDIUM);
+
+       case AM7XXX_POWER_HIGH:
+               return send_command(dev, AM7XXX_PACKET_TYPE_PICOPIX_POWER_HIGH);
+
+       case AM7XXX_POWER_OFF:
+       case AM7XXX_POWER_TURBO:
+       default:
+               error(dev->ctx, "Unsupported power mode.\n");
+               return -EINVAL;
+       };
+}
+
+static int default_set_zoom_mode(am7xxx_device *dev, am7xxx_zoom_mode zoom)
+{
+       int ret;
+       struct am7xxx_header h = {
+               .packet_type     = AM7XXX_PACKET_TYPE_ZOOM,
+               .direction       = AM7XXX_DIRECTION_OUT,
+               .header_data_len = sizeof(struct am7xxx_zoom_header),
+               .unknown2        = 0x3e,
+               .unknown3        = 0x10,
+       };
+
+       switch(zoom) {
+       case AM7XXX_ZOOM_ORIGINAL:
+               h.header_data.zoom.bit1 = 0;
+               h.header_data.zoom.bit0 = 0;
+               break;
+
+       case AM7XXX_ZOOM_H:
+               h.header_data.zoom.bit1 = 0;
+               h.header_data.zoom.bit0 = 1;
+               break;
+
+       case AM7XXX_ZOOM_H_V:
+               h.header_data.zoom.bit1 = 1;
+               h.header_data.zoom.bit0 = 0;
+               break;
+
+       case AM7XXX_ZOOM_TEST:
+               h.header_data.zoom.bit1 = 1;
+               h.header_data.zoom.bit0 = 1;
+               break;
+
+       case AM7XXX_ZOOM_TELE:
+       default:
+               error(dev->ctx, "Unsupported zoom mode.\n");
+               return -EINVAL;
+       };
+
+       ret = send_header(dev, &h);
+       if (ret < 0)
+               return ret;
+
+       return 0;
+}
+
+static int picopix_set_zoom_mode(am7xxx_device *dev, am7xxx_zoom_mode zoom)
+{
+       int ret;
+       am7xxx_packet_type packet_type;
+
+       switch(zoom) {
+       case AM7XXX_ZOOM_ORIGINAL:
+               packet_type = AM7XXX_PACKET_TYPE_PICOPIX_DISABLE_TI;
+               break;
+
+       case AM7XXX_ZOOM_TELE:
+               packet_type = AM7XXX_PACKET_TYPE_PICOPIX_ENABLE_TI;
+               break;
+
+       case AM7XXX_ZOOM_H:
+       case AM7XXX_ZOOM_H_V:
+       case AM7XXX_ZOOM_TEST:
+       default:
+               error(dev->ctx, "Unsupported zoom mode.\n");
+               return -EINVAL;
+       };
+
+       ret = send_command(dev, packet_type);
+       if (ret < 0)
+               return ret;
+
+       /* The Windows drivers wait for 100ms and send the same command again,
+        * probably to overcome a firmware deficiency */
+       ret = msleep(100);
+       if (ret < 0)
+               return ret;
+
+       return send_command(dev, packet_type);
+}
+
+/* Public API */
+
+AM7XXX_PUBLIC int am7xxx_init(am7xxx_context **ctx)
+{
+       int ret;
 
        *ctx = malloc(sizeof(**ctx));
        if (*ctx == NULL) {
 
        *ctx = malloc(sizeof(**ctx));
        if (*ctx == NULL) {
@@ -568,7 +1093,7 @@ int am7xxx_init(am7xxx_context **ctx)
        if (ret < 0)
                goto out_free_context;
 
        if (ret < 0)
                goto out_free_context;
 
-       libusb_set_debug((*ctx)->usb_context, 3);
+       libusb_set_debug((*ctx)->usb_context, LIBUSB_LOG_LEVEL_INFO);
 
        ret = scan_devices(*ctx, SCAN_OP_BUILD_DEVLIST , 0, NULL);
        if (ret < 0) {
 
        ret = scan_devices(*ctx, SCAN_OP_BUILD_DEVLIST , 0, NULL);
        if (ret < 0) {
@@ -588,7 +1113,7 @@ out:
        return ret;
 }
 
        return ret;
 }
 
-void am7xxx_shutdown(am7xxx_context *ctx)
+AM7XXX_PUBLIC void am7xxx_shutdown(am7xxx_context *ctx)
 {
        am7xxx_device *current;
 
 {
        am7xxx_device *current;
 
@@ -601,6 +1126,7 @@ void am7xxx_shutdown(am7xxx_context *ctx)
        while (current) {
                am7xxx_device *next = current->next;
                am7xxx_close_device(current);
        while (current) {
                am7xxx_device *next = current->next;
                am7xxx_close_device(current);
+               free(current->device_info);
                free(current);
                current = next;
        }
                free(current);
                current = next;
        }
@@ -610,12 +1136,12 @@ void am7xxx_shutdown(am7xxx_context *ctx)
        ctx = NULL;
 }
 
        ctx = NULL;
 }
 
-void am7xxx_set_log_level(am7xxx_context *ctx, am7xxx_log_level log_level)
+AM7XXX_PUBLIC void am7xxx_set_log_level(am7xxx_context *ctx, am7xxx_log_level log_level)
 {
        ctx->log_level = log_level;
 }
 
 {
        ctx->log_level = log_level;
 }
 
-int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
+AM7XXX_PUBLIC int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
                       unsigned int device_index)
 {
        int ret;
                       unsigned int device_index)
 {
        int ret;
@@ -628,79 +1154,165 @@ int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
        ret = scan_devices(ctx, SCAN_OP_OPEN_DEVICE, device_index, dev);
        if (ret < 0) {
                errno = ENODEV;
        ret = scan_devices(ctx, SCAN_OP_OPEN_DEVICE, device_index, dev);
        if (ret < 0) {
                errno = ENODEV;
+               goto out;
        } else if (ret > 0) {
                warning(ctx, "device %d already open\n", device_index);
                errno = EBUSY;
                ret = -EBUSY;
        } else if (ret > 0) {
                warning(ctx, "device %d already open\n", device_index);
                errno = EBUSY;
                ret = -EBUSY;
+               goto out;
        }
 
        }
 
+       /* Philips/Sagemcom PicoPix projectors require that the DEVINFO packet
+        * is the first one to be sent to the device in order for it to
+        * successfully return the correct device information.
+        *
+        * So, if there is not a cached version of it (from a previous open),
+        * we ask for device info at open time,
+        */
+       if ((*dev)->device_info == NULL) {
+               ret = am7xxx_get_device_info(*dev, NULL);
+               if (ret < 0)
+                       error(ctx, "cannot get device info\n");
+       }
+
+out:
        return ret;
 }
 
        return ret;
 }
 
-int am7xxx_close_device(am7xxx_device *dev)
+AM7XXX_PUBLIC int am7xxx_close_device(am7xxx_device *dev)
 {
        if (dev == NULL) {
                fatal("dev must not be NULL!\n");
                return -EINVAL;
        }
        if (dev->usb_device) {
 {
        if (dev == NULL) {
                fatal("dev must not be NULL!\n");
                return -EINVAL;
        }
        if (dev->usb_device) {
-               libusb_release_interface(dev->usb_device, 0);
+               wait_for_trasfer_completed(dev);
+               libusb_release_interface(dev->usb_device, dev->desc->interface_number);
                libusb_close(dev->usb_device);
                dev->usb_device = NULL;
        }
        return 0;
 }
 
                libusb_close(dev->usb_device);
                dev->usb_device = NULL;
        }
        return 0;
 }
 
-int am7xxx_get_device_info(am7xxx_device *dev,
+AM7XXX_PUBLIC int am7xxx_get_device_info(am7xxx_device *dev,
                           am7xxx_device_info *device_info)
 {
        int ret;
                           am7xxx_device_info *device_info)
 {
        int ret;
-       struct am7xxx_header h = {
-               .packet_type     = AM7XXX_PACKET_TYPE_DEVINFO,
-               .unknown0        = 0x00,
-               .header_data_len = 0x00,
-               .unknown2        = 0x3e,
-               .unknown3        = 0x10,
-               .header_data = {
-                       .devinfo = {
-                               .native_width  = 0,
-                               .native_height = 0,
-                               .unknown0      = 0,
-                               .unknown1      = 0,
-                       },
-               },
-       };
+       struct am7xxx_header h;
 
 
-       ret = send_header(dev, &h);
+       if (dev->device_info) {
+               memcpy(device_info, dev->device_info, sizeof(*device_info));
+               return 0;
+       }
+
+       ret = send_command(dev, AM7XXX_PACKET_TYPE_DEVINFO);
        if (ret < 0)
                return ret;
 
        if (ret < 0)
                return ret;
 
+       memset(&h, 0, sizeof(h));
        ret = read_header(dev, &h);
        if (ret < 0)
                return ret;
 
        ret = read_header(dev, &h);
        if (ret < 0)
                return ret;
 
-       device_info->native_width = h.header_data.devinfo.native_width;
-       device_info->native_height = h.header_data.devinfo.native_height;
+       if (h.packet_type != AM7XXX_PACKET_TYPE_DEVINFO) {
+               error(dev->ctx, "expected packet type: %d, got %d instead!\n",
+                     AM7XXX_PACKET_TYPE_DEVINFO, h.packet_type);
+               errno = ENOTSUP;
+               return -ENOTSUP;
+       }
+
+       dev->device_info = malloc(sizeof(*dev->device_info));
+       if (dev->device_info == NULL) {
+               error(dev->ctx, "cannot allocate a device info (%s)\n",
+                      strerror(errno));
+               return -ENOMEM;
+       }
+       memset(dev->device_info, 0, sizeof(*dev->device_info));
+
+       dev->device_info->native_width = h.header_data.devinfo.native_width;
+       dev->device_info->native_height = h.header_data.devinfo.native_height;
 #if 0
        /* No reason to expose these in the public API until we know what they mean */
 #if 0
        /* No reason to expose these in the public API until we know what they mean */
-       device_info->unknown0 = h.header_data.devinfo.unknown0;
-       device_info->unknown1 = h.header_data.devinfo.unknown1;
+       dev->device_info->unknown0 = h.header_data.devinfo.unknown0;
+       dev->device_info->unknown1 = h.header_data.devinfo.unknown1;
 #endif
 
        return 0;
 }
 
 #endif
 
        return 0;
 }
 
-int am7xxx_send_image(am7xxx_device *dev,
+AM7XXX_PUBLIC int am7xxx_calc_scaled_image_dimensions(am7xxx_device *dev,
+                                       unsigned int upscale,
+                                       unsigned int original_width,
+                                       unsigned int original_height,
+                                       unsigned int *scaled_width,
+                                       unsigned int *scaled_height)
+{
+
+       am7xxx_device_info device_info;
+       float width_ratio;
+       float height_ratio;
+       int ret;
+
+       ret = am7xxx_get_device_info(dev, &device_info);
+       if (ret < 0) {
+               error(dev->ctx, "cannot get device info\n");
+               return ret;
+       }
+
+       /*
+        * Check if we need to rescale; if the input image fits the native
+        * dimensions there is no need to, unless we want to upscale.
+        */
+       if (!upscale &&
+           original_width <= device_info.native_width &&
+           original_height <= device_info.native_height ) {
+               debug(dev->ctx, "CASE 0, no rescaling, the original image fits already\n");
+               *scaled_width = original_width;
+               *scaled_height = original_height;
+               return 0;
+       }
+
+       /* Input dimensions relative to the device native dimensions */
+       width_ratio =  (float)original_width / device_info.native_width;
+       height_ratio = (float)original_height / device_info.native_height;
+
+       if (width_ratio > height_ratio) {
+               /*
+                * The input is proportionally "wider" than the device viewport
+                * so its height needs to be adjusted
+                */
+               debug(dev->ctx, "CASE 1, original image wider, adjust the scaled height\n");
+               *scaled_width = device_info.native_width;
+               *scaled_height = (unsigned int)lroundf(original_height / width_ratio);
+       } else if (width_ratio < height_ratio) {
+               /*
+                * The input is proportionally "taller" than the device viewport
+                * so its width needs to be adjusted
+                */
+               debug(dev->ctx, "CASE 2 original image taller, adjust the scaled width\n");
+               *scaled_width = (unsigned int)lroundf(original_width / height_ratio);
+               *scaled_height = device_info.native_height;
+       } else {
+               debug(dev->ctx, "CASE 3, just rescale, same aspect ratio already\n");
+               *scaled_width = device_info.native_width;
+               *scaled_height = device_info.native_height;
+       }
+       debug(dev->ctx, "scaled dimensions: %dx%d\n", *scaled_width, *scaled_height);
+
+       return 0;
+}
+
+AM7XXX_PUBLIC int am7xxx_send_image(am7xxx_device *dev,
                      am7xxx_image_format format,
                      unsigned int width,
                      unsigned int height,
                      uint8_t *image,
                      am7xxx_image_format format,
                      unsigned int width,
                      unsigned int height,
                      uint8_t *image,
-                     unsigned int size)
+                     unsigned int image_size)
 {
        int ret;
        struct am7xxx_header h = {
                .packet_type     = AM7XXX_PACKET_TYPE_IMAGE,
 {
        int ret;
        struct am7xxx_header h = {
                .packet_type     = AM7XXX_PACKET_TYPE_IMAGE,
-               .unknown0        = 0x00,
+               .direction       = AM7XXX_DIRECTION_OUT,
                .header_data_len = sizeof(struct am7xxx_image_header),
                .unknown2        = 0x3e,
                .unknown3        = 0x10,
                .header_data_len = sizeof(struct am7xxx_image_header),
                .unknown2        = 0x3e,
                .unknown3        = 0x10,
@@ -709,7 +1321,7 @@ int am7xxx_send_image(am7xxx_device *dev,
                                .format     = format,
                                .width      = width,
                                .height     = height,
                                .format     = format,
                                .width      = width,
                                .height     = height,
-                               .image_size = size,
+                               .image_size = image_size,
                        },
                },
        };
                        },
                },
        };
@@ -718,63 +1330,68 @@ int am7xxx_send_image(am7xxx_device *dev,
        if (ret < 0)
                return ret;
 
        if (ret < 0)
                return ret;
 
-       if (image == NULL || size == 0) {
-               warning(dev->ctx, "Not sending any data, check the 'data' or 'size' parameters\n");
+       if (image == NULL || image_size == 0) {
+               warning(dev->ctx, "Not sending any data, check the 'image' or 'image_size' parameters\n");
                return 0;
        }
 
                return 0;
        }
 
-       return send_data(dev, image, size);
+       return send_data(dev, image, image_size);
 }
 
 }
 
-int am7xxx_set_power_mode(am7xxx_device *dev, am7xxx_power_mode mode)
+AM7XXX_PUBLIC int am7xxx_send_image_async(am7xxx_device *dev,
+                                         am7xxx_image_format format,
+                                         unsigned int width,
+                                         unsigned int height,
+                                         uint8_t *image,
+                                         unsigned int image_size)
 {
        int ret;
        struct am7xxx_header h = {
 {
        int ret;
        struct am7xxx_header h = {
-               .packet_type     = AM7XXX_PACKET_TYPE_POWER,
-               .unknown0        = 0x00,
-               .header_data_len = sizeof(struct am7xxx_power_header),
+               .packet_type     = AM7XXX_PACKET_TYPE_IMAGE,
+               .direction       = AM7XXX_DIRECTION_OUT,
+               .header_data_len = sizeof(struct am7xxx_image_header),
                .unknown2        = 0x3e,
                .unknown3        = 0x10,
                .unknown2        = 0x3e,
                .unknown3        = 0x10,
+               .header_data = {
+                       .image = {
+                               .format     = format,
+                               .width      = width,
+                               .height     = height,
+                               .image_size = image_size,
+                       },
+               },
        };
 
        };
 
-       switch(mode) {
-       case AM7XXX_POWER_OFF:
-               h.header_data.power.bit2 = 0;
-               h.header_data.power.bit1 = 0;
-               h.header_data.power.bit0 = 0;
-               break;
-
-       case AM7XXX_POWER_LOW:
-               h.header_data.power.bit2 = 0;
-               h.header_data.power.bit1 = 0;
-               h.header_data.power.bit0 = 1;
+       ret = send_header(dev, &h);
+       if (ret < 0)
+               return ret;
 
 
-       case AM7XXX_POWER_MIDDLE:
-               h.header_data.power.bit2 = 0;
-               h.header_data.power.bit1 = 1;
-               h.header_data.power.bit0 = 0;
-               break;
+       if (image == NULL || image_size == 0) {
+               warning(dev->ctx, "Not sending any data, check the 'image' or 'image_size' parameters\n");
+               return 0;
+       }
 
 
-       case AM7XXX_POWER_HIGH:
-               h.header_data.power.bit2 = 0;
-               h.header_data.power.bit1 = 1;
-               h.header_data.power.bit0 = 1;
-               break;
+       return send_data_async(dev, image, image_size);
+}
 
 
-       case AM7XXX_POWER_TURBO:
-               h.header_data.power.bit2 = 1;
-               h.header_data.power.bit1 = 0;
-               h.header_data.power.bit0 = 0;
-               break;
+AM7XXX_PUBLIC int am7xxx_set_power_mode(am7xxx_device *dev, am7xxx_power_mode power)
+{
+       if (dev->desc->ops.set_power_mode == NULL) {
+               warning(dev->ctx,
+                       "setting power mode is unsupported on this device\n");
+               return 0;
+       }
 
 
-       default:
-               error(dev->ctx, "Power mode not supported!\n");
-               return -EINVAL;
-       };
+       return dev->desc->ops.set_power_mode(dev, power);
+}
 
 
-       ret = send_header(dev, &h);
-       if (ret < 0)
-               return ret;
+AM7XXX_PUBLIC int am7xxx_set_zoom_mode(am7xxx_device *dev, am7xxx_zoom_mode zoom)
+{
+       if (dev->desc->ops.set_zoom_mode == NULL) {
+               warning(dev->ctx,
+                       "setting zoom mode is unsupported on this device\n");
+               return 0;
+       }
 
 
-       return 0;
+       return dev->desc->ops.set_zoom_mode(dev, zoom);
 }
 }