3 files changed, 25 insertions, 0 deletions

diff --git a/drivers/media/video/cx23885/cx23885-cards.c b/drivers/media/video/cx23885/cx23885-cards.c
index 901bebcca7c3..a4bac43cf9f5 100644
--- a/drivers/media/video/cx23885/cx23885-cards.c
+++ b/drivers/media/video/cx23885/cx23885-cards.c
@@ -32,6 +32,8 @@
 struct cx23885_board cx23885_boards[] = {
         [CX23885_BOARD_UNKNOWN] = {
                 .name           = "UNKNOWN/GENERIC",
+                /* Ensure safe default for unknown boards */
+                .clk_freq       = 0,
                 .input          = {{
                         .type   = CX23885_VMUX_COMPOSITE1,
                         .vmux   = 0,
diff --git a/drivers/media/video/cx23885/cx23885-core.c b/drivers/media/video/cx23885/cx23885-core.c
index 31723dd7cbdc..8616a26895d8 100644
--- a/drivers/media/video/cx23885/cx23885-core.c
+++ b/drivers/media/video/cx23885/cx23885-core.c
@@ -759,10 +759,14 @@ static int cx23885_dev_setup(struct cx23885_dev *dev)
         if(dev->pci->device == 0x8880) {
                 dev->bridge = CX23885_BRIDGE_887;
                 dev->sram_channels = cx23887_sram_channels;
+                /* Apply a sensible clock frequency for the PCIe bridge */
+                dev->clk_freq = 25000000;
         } else
         if(dev->pci->device == 0x8852) {
                 dev->bridge = CX23885_BRIDGE_885;
                 dev->sram_channels = cx23885_sram_channels;
+                /* Apply a sensible clock frequency for the PCIe bridge */
+                dev->clk_freq = 28000000;
         } else
                 BUG();
 
@@ -782,6 +786,10 @@ static int cx23885_dev_setup(struct cx23885_dev *dev)
                 cx23885_card_list(dev);
         }
 
+        /* If the user specific a clk freq override, apply it */
+        if (cx23885_boards[dev->board].clk_freq > 0)
+                dev->clk_freq = cx23885_boards[dev->board].clk_freq;
+
         dev->pci_bus  = dev->pci->bus->number;
         dev->pci_slot = PCI_SLOT(dev->pci->devfn);
         dev->pci_irqmask = 0x001f00;
diff --git a/drivers/media/video/cx23885/cx23885.h b/drivers/media/video/cx23885/cx23885.h
index 48d0c87ddbc2..b957242dcd5e 100644
--- a/drivers/media/video/cx23885/cx23885.h
+++ b/drivers/media/video/cx23885/cx23885.h
@@ -100,6 +100,17 @@ typedef enum {
 struct cx23885_board {
         char                    *name;
         port_t                  portb, portc;
+
+        /* Vendors can and do run the PCIe bridge at different
+         * clock rates, driven physically by crystals on the PCBs.
+         * The core has to accomodate this. This allows the user
+         * to add new boards with new frequencys. The value is
+         * expressed in Hz.
+         *
+         * The core framework will default this value based on
+         * current designs, but it can vary.
+         */
+        u32                     clk_freq;
         struct cx23885_input    input[MAX_CX23885_INPUT];
 };
 
@@ -193,6 +204,10 @@ struct cx23885_dev {
         int                        pci_irqmask;
         int                        hwrevision;
 
+        /* This valud is board specific and is used to configure the
+         * AV core so we see nice clean and stable video and audio. */
+        u32                        clk_freq;
+
         /* I2C adapters: Master 1 & 2 (External) & Master 3 (Internal only) */
         struct cx23885_i2c         i2c_bus[3];