firewire: Implement basic isochronous receive functionality.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

1 files changed, 149 insertions, 19 deletions

diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index 86fe55cff28a..90db5a4f3aee 100644
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -45,6 +45,7 @@
 #define descriptor_irq_error            (1 << 4)
 #define descriptor_irq_always           (3 << 4)
 #define descriptor_branch_always        (3 << 2)
+#define descriptor_wait                 (3 << 0)
 
 struct descriptor {
         __le16 req_count;
@@ -55,6 +56,20 @@ struct descriptor {
         __le16 transfer_status;
 } __attribute__((aligned(16)));
 
+struct db_descriptor {
+        __le16 first_size;
+        __le16 control;
+        __le16 second_req_count;
+        __le16 first_req_count;
+        __le32 branch_address;
+        __le16 second_res_count;
+        __le16 first_res_count;
+        __le32 reserved0;
+        __le32 first_buffer;
+        __le32 second_buffer;
+        __le32 reserved1;
+} __attribute__((aligned(16)));
+
 #define control_set(regs)       (regs)
 #define control_clear(regs)     ((regs) + 4)
 #define command_ptr(regs)       ((regs) + 12)
@@ -171,7 +186,12 @@ static inline struct fw_ohci *fw_ohci(struct fw_card *card)
         return container_of(card, struct fw_ohci, card);
 }
 
-#define CONTEXT_CYCLE_MATCH_ENABLE      0x80000000
+#define IT_CONTEXT_CYCLE_MATCH_ENABLE   0x80000000
+#define IR_CONTEXT_BUFFER_FILL          0x80000000
+#define IR_CONTEXT_ISOCH_HEADER         0x40000000
+#define IR_CONTEXT_CYCLE_MATCH_ENABLE   0x20000000
+#define IR_CONTEXT_MULTI_CHANNEL_MODE   0x10000000
+#define IR_CONTEXT_DUAL_BUFFER_MODE     0x08000000
 
 #define CONTEXT_RUN     0x8000
 #define CONTEXT_WAKE    0x1000
@@ -518,14 +538,14 @@ context_get_descriptors(struct context *ctx, int z, dma_addr_t *d_bus)
         return d;
 }
 
-static void context_run(struct context *ctx, u32 cycle_match)
+static void context_run(struct context *ctx, u32 extra)
 {
         struct fw_ohci *ohci = ctx->ohci;
 
         reg_write(ohci, command_ptr(ctx->regs),
                   le32_to_cpu(ctx->tail_descriptor_last->branch_address));
         reg_write(ohci, control_clear(ctx->regs), ~0);
-        reg_write(ohci, control_set(ctx->regs), CONTEXT_RUN | cycle_match);
+        reg_write(ohci, control_set(ctx->regs), CONTEXT_RUN | extra);
         flush_writes(ohci);
 }
 
@@ -1240,11 +1260,25 @@ ohci_enable_phys_dma(struct fw_card *card, int node_id, int generation)
         return retval;
 }
 
-static void ir_context_tasklet(unsigned long data)
+static int handle_ir_packet(struct context *context,
+                            struct descriptor *d,
+                            struct descriptor *last)
 {
-        struct iso_context *ctx = (struct iso_context *)data;
+        struct iso_context *ctx =
+                container_of(context, struct iso_context, context);
+        struct db_descriptor *db = (struct db_descriptor *) d;
+ 
+        if (db->first_res_count > 0 && db->second_res_count > 0)
+                /* This descriptor isn't done yet, stop iteration. */
+                return 0;
+
+        if (le16_to_cpu(db->control) & descriptor_irq_always)
+                /* FIXME: we should pass payload address here. */
+                ctx->base.callback(&ctx->base,
+                                   0, 0,
+                                   ctx->base.callback_data);
 
-        (void)ctx;
+        return 1;
 }
 
 #define ISO_BUFFER_SIZE (64 * 1024)
@@ -1274,7 +1308,7 @@ ohci_allocate_iso_context(struct fw_card *card, int type)
         struct fw_ohci *ohci = fw_ohci(card);
         struct iso_context *ctx, *list;
         descriptor_callback_t callback;
-        u32 *mask;
+        u32 *mask, regs;
         unsigned long flags;
         int index, retval;
 
@@ -1283,7 +1317,9 @@ ohci_allocate_iso_context(struct fw_card *card, int type)
                 list = ohci->it_context_list;
                 callback = handle_it_packet;
         } else {
-                return ERR_PTR(-EINVAL);
+                mask = &ohci->ir_context_mask;
+                list = ohci->ir_context_list;
+                callback = handle_ir_packet;
         }
 
         spin_lock_irqsave(&ohci->lock, flags);
@@ -1295,10 +1331,15 @@ ohci_allocate_iso_context(struct fw_card *card, int type)
         if (index < 0)
                 return ERR_PTR(-EBUSY);
 
+        if (type == FW_ISO_CONTEXT_TRANSMIT)
+                regs = OHCI1394_IsoXmitContextBase(index);
+        else
+                regs = OHCI1394_IsoRcvContextBase(index);
+ 
         ctx = &list[index];
         memset(ctx, 0, sizeof *ctx);
         retval = context_init(&ctx->context, ohci, ISO_BUFFER_SIZE,
-                              OHCI1394_IsoXmitContextBase(index), callback);
+                              regs, callback);
         if (retval < 0) {
                 spin_lock_irqsave(&ohci->lock, flags);
                 *mask |= 1 << index;
@@ -1316,13 +1357,24 @@ static int ohci_send_iso(struct fw_iso_context *base, s32 cycle)
         u32 cycle_match = 0;
         int index;
 
-        index = ctx - ohci->it_context_list;
-        if (cycle > 0)
-                cycle_match = CONTEXT_CYCLE_MATCH_ENABLE |
-                        (cycle & 0x7fff) << 16;
+        if (ctx->base.type == FW_ISO_CONTEXT_TRANSMIT) {
+                index = ctx - ohci->it_context_list;
+                if (cycle > 0)
+                        cycle_match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
+                                (cycle & 0x7fff) << 16;
+                
+                reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
+                reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
+                context_run(&ctx->context, cycle_match);
+        } else {
+                index = ctx - ohci->ir_context_list;
 
-        reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
-        context_run(&ctx->context, cycle_match);
+                reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
+                reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
+                reg_write(ohci, context_match(ctx->context.regs),
+                          0xf0000000 | ctx->base.channel);
+                context_run(&ctx->context, IR_CONTEXT_DUAL_BUFFER_MODE);
+        }
 
         return 0;
 }
@@ -1355,10 +1407,10 @@ static void ohci_free_iso_context(struct fw_iso_context *base)
 }
 
 static int
-ohci_queue_iso(struct fw_iso_context *base,
-               struct fw_iso_packet *packet,
-               struct fw_iso_buffer *buffer,
-               unsigned long payload)
+ohci_queue_iso_transmit(struct fw_iso_context *base,
+                        struct fw_iso_packet *packet,
+                        struct fw_iso_buffer *buffer,
+                        unsigned long payload)
 {
         struct iso_context *ctx = container_of(base, struct iso_context, base);
         struct descriptor *d, *last, *pd;
@@ -1451,6 +1503,84 @@ ohci_queue_iso(struct fw_iso_context *base,
         return 0;
 }
 
+static int
+ohci_queue_iso_receive(struct fw_iso_context *base,
+                       struct fw_iso_packet *packet,
+                       struct fw_iso_buffer *buffer,
+                       unsigned long payload)
+{
+        struct iso_context *ctx = container_of(base, struct iso_context, base);
+        struct db_descriptor *db = NULL;
+        struct descriptor *d;
+        struct fw_iso_packet *p;
+        dma_addr_t d_bus, page_bus;
+        u32 z, header_z, length, rest;
+        int page, offset;
+ 
+        /* FIXME: Cycle lost behavior should be configurable: lose
+         * packet, retransmit or terminate.. */
+
+        p = packet;
+        z = 2;
+
+        /* Get header size in number of descriptors. */
+        header_z = DIV_ROUND_UP(p->header_length, sizeof *d);
+        page     = payload >> PAGE_SHIFT;
+        offset   = payload & ~PAGE_MASK;
+        rest     = p->payload_length;
+
+        /* FIXME: OHCI 1.0 doesn't support dual buffer receive */
+        /* FIXME: handle descriptor_wait */
+        /* FIXME: make packet-per-buffer/dual-buffer a context option */
+        while (rest > 0) {
+                d = context_get_descriptors(&ctx->context,
+                                            z + header_z, &d_bus);
+                if (d == NULL)
+                        return -ENOMEM;
+
+                db = (struct db_descriptor *) d;
+                db->control = cpu_to_le16(descriptor_status |
+                                          descriptor_branch_always);
+                db->first_size = cpu_to_le16(ctx->base.header_size);
+                db->first_req_count = cpu_to_le16(p->header_length);
+                db->second_req_count = cpu_to_le16(p->payload_length);
+                db->first_res_count = cpu_to_le16(db->first_req_count);
+                db->second_res_count = cpu_to_le16(db->second_req_count);
+
+                db->first_buffer = cpu_to_le32(d_bus + sizeof *db);
+                
+                if (offset + rest < PAGE_SIZE)
+                        length = rest;
+                else
+                        length = PAGE_SIZE - offset;
+
+                page_bus = page_private(buffer->pages[page]);
+                db->second_buffer = cpu_to_le32(page_bus + offset);
+
+                context_append(&ctx->context, d, z, header_z);
+                offset = (offset + length) & ~PAGE_MASK;
+                rest -= length;
+                page++;
+        }
+
+        if (p->interrupt)
+                db->control |= cpu_to_le16(descriptor_irq_always);
+ 
+        return 0;
+ }
+ 
+static int
+ohci_queue_iso(struct fw_iso_context *base,
+               struct fw_iso_packet *packet,
+               struct fw_iso_buffer *buffer,
+               unsigned long payload)
+{
+        if (base->type == FW_ISO_CONTEXT_TRANSMIT)
+                return ohci_queue_iso_transmit(base, packet, buffer, payload);
+        else
+                return ohci_queue_iso_receive(base, packet, buffer, payload);
+}
+
 static const struct fw_card_driver ohci_driver = {
         .name                   = ohci_driver_name,
         .enable                 = ohci_enable,