[patch 05/12] MIPS: BCM63XX: Change PCI code to emulate a fake cardbus bridge.

[Ralf Baechle <ralf@linux-mips.org>]

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From:	Maxime Bizon <mbizon@freebox.fr>

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

 arch/mips/pci/ops-bcm63xx.c |  288 ++++++++++++++++++++++++++++++++++++++++++++
 arch/mips/pci/pci-bcm63xx.c |   44 ++++++
 2 files changed, 332 insertions(+)

--- a/arch/mips/pci/ops-bcm63xx.c
+++ b/arch/mips/pci/ops-bcm63xx.c
@@ -177,3 +177,291 @@ struct pci_ops bcm63xx_pci_ops = {
 	.read   = bcm63xx_pci_read,
 	.write  = bcm63xx_pci_write
 };
+
+#ifdef CONFIG_CARDBUS
+/*
+ * emulate configuration read access on a cardbus bridge
+ */
+#define FAKE_CB_BRIDGE_SLOT	0x1e
+
+static int fake_cb_bridge_bus_number = -1;
+
+static struct {
+	u16 pci_command;
+	u8 cb_latency;
+	u8 subordinate_busn;
+	u8 cardbus_busn;
+	u8 pci_busn;
+	int bus_assigned;
+	u16 bridge_control;
+
+	u32 mem_base0;
+	u32 mem_limit0;
+	u32 mem_base1;
+	u32 mem_limit1;
+
+	u32 io_base0;
+	u32 io_limit0;
+	u32 io_base1;
+	u32 io_limit1;
+} fake_cb_bridge_regs;
+
+static int fake_cb_bridge_read(int where, int size, u32 *val)
+{
+	unsigned int reg;
+	u32 data;
+
+	data = 0;
+	reg = where >> 2;
+	switch (reg) {
+	case (PCI_VENDOR_ID >> 2):
+	case (PCI_CB_SUBSYSTEM_VENDOR_ID >> 2):
+		/* create dummy vendor/device id from our cpu id */
+		data = (bcm63xx_get_cpu_id() << 16) | PCI_VENDOR_ID_BROADCOM;
+		break;
+
+	case (PCI_COMMAND >> 2):
+		data = (PCI_STATUS_DEVSEL_SLOW << 16);
+		data |= fake_cb_bridge_regs.pci_command;
+		break;
+
+	case (PCI_CLASS_REVISION >> 2):
+		data = (PCI_CLASS_BRIDGE_CARDBUS << 16);
+		break;
+
+	case (PCI_CACHE_LINE_SIZE >> 2):
+		data = (PCI_HEADER_TYPE_CARDBUS << 16);
+		break;
+
+	case (PCI_INTERRUPT_LINE >> 2):
+		/* bridge control */
+		data = (fake_cb_bridge_regs.bridge_control << 16);
+		/* pin:intA line:0xff */
+		data |= (0x1 << 8) | 0xff;
+		break;
+
+	case (PCI_CB_PRIMARY_BUS >> 2):
+		data = (fake_cb_bridge_regs.cb_latency << 24);
+		data |= (fake_cb_bridge_regs.subordinate_busn << 16);
+		data |= (fake_cb_bridge_regs.cardbus_busn << 8);
+		data |= fake_cb_bridge_regs.pci_busn;
+		break;
+
+	case (PCI_CB_MEMORY_BASE_0 >> 2):
+		data = fake_cb_bridge_regs.mem_base0;
+		break;
+
+	case (PCI_CB_MEMORY_LIMIT_0 >> 2):
+		data = fake_cb_bridge_regs.mem_limit0;
+		break;
+
+	case (PCI_CB_MEMORY_BASE_1 >> 2):
+		data = fake_cb_bridge_regs.mem_base1;
+		break;
+
+	case (PCI_CB_MEMORY_LIMIT_1 >> 2):
+		data = fake_cb_bridge_regs.mem_limit1;
+		break;
+
+	case (PCI_CB_IO_BASE_0 >> 2):
+		/* | 1 for 32bits io support */
+		data = fake_cb_bridge_regs.io_base0 | 0x1;
+		break;
+
+	case (PCI_CB_IO_LIMIT_0 >> 2):
+		data = fake_cb_bridge_regs.io_limit0;
+		break;
+
+	case (PCI_CB_IO_BASE_1 >> 2):
+		/* | 1 for 32bits io support */
+		data = fake_cb_bridge_regs.io_base1 | 0x1;
+		break;
+
+	case (PCI_CB_IO_LIMIT_1 >> 2):
+		data = fake_cb_bridge_regs.io_limit1;
+		break;
+	}
+
+	*val = postprocess_read(data, where, size);
+	return PCIBIOS_SUCCESSFUL;
+}
+
+/*
+ * emulate configuration write access on a cardbus bridge
+ */
+static int fake_cb_bridge_write(int where, int size, u32 val)
+{
+	unsigned int reg;
+	u32 data, tmp;
+	int ret;
+
+	ret = fake_cb_bridge_read((where & ~0x3), 4, &data);
+	if (ret != PCIBIOS_SUCCESSFUL)
+		return ret;
+
+	data = preprocess_write(data, val, where, size);
+
+	reg = where >> 2;
+	switch (reg) {
+	case (PCI_COMMAND >> 2):
+		fake_cb_bridge_regs.pci_command = (data & 0xffff);
+		break;
+
+	case (PCI_CB_PRIMARY_BUS >> 2):
+		fake_cb_bridge_regs.cb_latency = (data >> 24) & 0xff;
+		fake_cb_bridge_regs.subordinate_busn = (data >> 16) & 0xff;
+		fake_cb_bridge_regs.cardbus_busn = (data >> 8) & 0xff;
+		fake_cb_bridge_regs.pci_busn = data & 0xff;
+		if (fake_cb_bridge_regs.cardbus_busn)
+			fake_cb_bridge_regs.bus_assigned = 1;
+		break;
+
+	case (PCI_INTERRUPT_LINE >> 2):
+		tmp = (data >> 16) & 0xffff;
+		/* disable memory prefetch support */
+		tmp &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
+		tmp &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
+		fake_cb_bridge_regs.bridge_control = tmp;
+		break;
+
+	case (PCI_CB_MEMORY_BASE_0 >> 2):
+		fake_cb_bridge_regs.mem_base0 = data;
+		break;
+
+	case (PCI_CB_MEMORY_LIMIT_0 >> 2):
+		fake_cb_bridge_regs.mem_limit0 = data;
+		break;
+
+	case (PCI_CB_MEMORY_BASE_1 >> 2):
+		fake_cb_bridge_regs.mem_base1 = data;
+		break;
+
+	case (PCI_CB_MEMORY_LIMIT_1 >> 2):
+		fake_cb_bridge_regs.mem_limit1 = data;
+		break;
+
+	case (PCI_CB_IO_BASE_0 >> 2):
+		fake_cb_bridge_regs.io_base0 = data;
+		break;
+
+	case (PCI_CB_IO_LIMIT_0 >> 2):
+		fake_cb_bridge_regs.io_limit0 = data;
+		break;
+
+	case (PCI_CB_IO_BASE_1 >> 2):
+		fake_cb_bridge_regs.io_base1 = data;
+		break;
+
+	case (PCI_CB_IO_LIMIT_1 >> 2):
+		fake_cb_bridge_regs.io_limit1 = data;
+		break;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int bcm63xx_cb_read(struct pci_bus *bus, unsigned int devfn,
+			   int where, int size, u32 *val)
+{
+	/* snoop access to slot 0x1e on root bus, we fake a cardbus
+	 * bridge at this location */
+	if (!bus->parent && PCI_SLOT(devfn) == FAKE_CB_BRIDGE_SLOT) {
+		fake_cb_bridge_bus_number = bus->number;
+		return fake_cb_bridge_read(where, size, val);
+	}
+
+	/* a  configuration  cycle for  the  device  behind the  cardbus
+	 * bridge is  actually done as a  type 0 cycle  on the primary
+	 * bus. This means that only  one device can be on the cardbus
+	 * bus */
+	if (fake_cb_bridge_regs.bus_assigned &&
+	    bus->number == fake_cb_bridge_regs.cardbus_busn &&
+	    PCI_SLOT(devfn) == 0)
+		return bcm63xx_do_cfg_read(0, 0,
+					   PCI_DEVFN(CARDBUS_PCI_IDSEL, 0),
+					   where, size, val);
+
+	return PCIBIOS_DEVICE_NOT_FOUND;
+}
+
+static int bcm63xx_cb_write(struct pci_bus *bus, unsigned int devfn,
+			    int where, int size, u32 val)
+{
+	if (!bus->parent && PCI_SLOT(devfn) == FAKE_CB_BRIDGE_SLOT) {
+		fake_cb_bridge_bus_number = bus->number;
+		return fake_cb_bridge_write(where, size, val);
+	}
+
+	if (fake_cb_bridge_regs.bus_assigned &&
+	    bus->number == fake_cb_bridge_regs.cardbus_busn &&
+	    PCI_SLOT(devfn) == 0)
+		return bcm63xx_do_cfg_write(0, 0,
+					    PCI_DEVFN(CARDBUS_PCI_IDSEL, 0),
+					    where, size, val);
+
+	return PCIBIOS_DEVICE_NOT_FOUND;
+}
+
+struct pci_ops bcm63xx_cb_ops = {
+	.read   = bcm63xx_cb_read,
+	.write   = bcm63xx_cb_write,
+};
+
+/*
+ * only one IO window, so it  cannot be shared by PCI and cardbus, use
+ * fixup to choose and detect unhandled configuration
+ */
+static void bcm63xx_fixup(struct pci_dev *dev)
+{
+	static int io_window = -1;
+	int i, found, new_io_window;
+	u32 val;
+
+	/* look for any io resource */
+	found = 0;
+	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
+		if (pci_resource_flags(dev, i) & IORESOURCE_IO) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found)
+		return;
+
+	/* skip our fake bus with only cardbus bridge on it */
+	if (dev->bus->number == fake_cb_bridge_bus_number)
+		return;
+
+	/* find on which bus the device is */
+	if (fake_cb_bridge_regs.bus_assigned &&
+	    dev->bus->number == fake_cb_bridge_regs.cardbus_busn &&
+	    PCI_SLOT(dev->devfn) == 0)
+		new_io_window = 1;
+	else
+		new_io_window = 0;
+
+	if (new_io_window == io_window)
+		return;
+
+	if (io_window != -1) {
+		printk(KERN_ERR "bcm63xx: both PCI and cardbus devices "
+		       "need IO, which hardware cannot do\n");
+		return;
+	}
+
+	printk(KERN_INFO "bcm63xx: PCI IO window assigned to %s\n",
+	       (new_io_window == 0) ? "PCI" : "cardbus");
+
+	val = bcm_mpi_readl(MPI_L2PIOREMAP_REG);
+	if (io_window)
+		val |= MPI_L2PREMAP_IS_CARDBUS_MASK;
+	else
+		val &= ~MPI_L2PREMAP_IS_CARDBUS_MASK;
+	bcm_mpi_writel(val, MPI_L2PIOREMAP_REG);
+
+	io_window = new_io_window;
+}
+
+DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, bcm63xx_fixup);
+#endif
--- a/arch/mips/pci/pci-bcm63xx.c
+++ b/arch/mips/pci/pci-bcm63xx.c
@@ -30,7 +30,11 @@ static struct resource bcm_pci_mem_resou
 static struct resource bcm_pci_io_resource = {
 	.name   = "bcm63xx PCI IO space",
 	.start  = BCM_PCI_IO_BASE_PA,
+#ifdef CONFIG_CARDBUS
+	.end    = BCM_PCI_IO_HALF_PA,
+#else
 	.end    = BCM_PCI_IO_END_PA,
+#endif
 	.flags  = IORESOURCE_IO
 };
 
@@ -40,6 +44,33 @@ struct pci_controller bcm63xx_controller
 	.mem_resource	= &bcm_pci_mem_resource,
 };
 
+/*
+ * We handle cardbus  via a fake Cardbus bridge,  memory and io spaces
+ * have to be  clearly separated from PCI one  since we have different
+ * memory decoder.
+ */
+#ifdef CONFIG_CARDBUS
+static struct resource bcm_cb_mem_resource = {
+	.name   = "bcm63xx Cardbus memory space",
+	.start  = BCM_CB_MEM_BASE_PA,
+	.end    = BCM_CB_MEM_END_PA,
+	.flags  = IORESOURCE_MEM
+};
+
+static struct resource bcm_cb_io_resource = {
+	.name   = "bcm63xx Cardbus IO space",
+	.start  = BCM_PCI_IO_HALF_PA + 1,
+	.end    = BCM_PCI_IO_END_PA,
+	.flags  = IORESOURCE_IO
+};
+
+struct pci_controller bcm63xx_cb_controller = {
+	.pci_ops	= &bcm63xx_cb_ops,
+	.io_resource	= &bcm_cb_io_resource,
+	.mem_resource	= &bcm_cb_mem_resource,
+};
+#endif
+
 static u32 bcm63xx_int_cfg_readl(u32 reg)
 {
 	u32 tmp;
@@ -100,8 +131,17 @@ static int __init bcm63xx_pci_init(void)
 	val |= (CARDBUS_PCI_IDSEL << PCMCIA_C1_CBIDSEL_SHIFT);
 	bcm_pcmcia_writel(val, PCMCIA_C1_REG);
 
+#ifdef CONFIG_CARDBUS
+	/* setup local bus to PCI access (Cardbus memory) */
+	val = BCM_CB_MEM_BASE_PA & MPI_L2P_BASE_MASK;
+	bcm_mpi_writel(val, MPI_L2PMEMBASE2_REG);
+	bcm_mpi_writel(~(BCM_CB_MEM_SIZE - 1), MPI_L2PMEMRANGE2_REG);
+	val |= MPI_L2PREMAP_ENABLED_MASK | MPI_L2PREMAP_IS_CARDBUS_MASK;
+	bcm_mpi_writel(val, MPI_L2PMEMREMAP2_REG);
+#else
 	/* disable second access windows */
 	bcm_mpi_writel(0, MPI_L2PMEMREMAP2_REG);
+#endif
 
 	/* setup local bus  to PCI access (IO memory),  we have only 1
 	 * IO window  for both PCI  and cardbus, but it  cannot handle
@@ -171,6 +211,10 @@ static int __init bcm63xx_pci_init(void)
 
 	register_pci_controller(&bcm63xx_controller);
 
+#ifdef CONFIG_CARDBUS
+	register_pci_controller(&bcm63xx_cb_controller);
+#endif
+
 	/* mark memory space used for IO mapping as reserved */
 	request_mem_region(BCM_PCI_IO_BASE_PA, BCM_PCI_IO_SIZE,
 			   "bcm63xx PCI IO space");