src/devices/cardbus_device.c

/* (c) 2005 Linux Networx GPL see COPYING for details */

#include <console/console.h>
#include <device/device.h>
#include <device/pci.h>
#include <device/pci_ids.h>
#include <device/cardbus.h>

/* I don't think this code is quite correct but it is close.
 * Anyone with a cardbus bridge and a little time should be able
 * to make it usable quickly. -- Eric Biederman 24 March 2005
 */

/*
 * IO should be max 256 bytes.  However, since we may
 * have a P2P bridge below a cardbus bridge, we need 4K.
 */
#define CARDBUS_IO_SIZE		(4096)
#define CARDBUS_MEM_SIZE	(32*1024*1024)

static void cardbus_record_bridge_resource(
	device_t dev, resource_t moving, resource_t min_size,
	unsigned index, unsigned long type)
{
	/* Initiliaze the constraints on the current bus */
	struct resource *resource;
	resource = 0;
	if (moving) {
		unsigned long gran;
		resource_t step;
		resource = new_resource(dev, index);
		resource->size = 0;
		gran = 0;
		step = 1;
		while((moving & step) == 0) {
			gran += 1;
			step <<= 1;
		}
		resource->gran = gran;
		resource->align = gran;
		resource->limit = moving | (step - 1);
		resource->flags = type;
		/* Don't let the minimum size exceed what we
		 * can put in the resource.
		 */
		if ((min_size - 1) > resource->limit) {
			min_size = resource->limit + 1;
		}
		resource->size = min_size;
	}
	return;
}

static void cardbus_size_bridge_resource(device_t dev, unsigned index)
{
	struct resource *resource;
	resource_t min_size;
	resource = find_resource(dev, index);
	if (resource) {
		min_size = resource->size;
		compute_allocate_resource(&dev->link[0], resource, 
			resource->flags, resource->flags);
		/* Allways allocate at least the miniumum size to a
		 * cardbus bridge in case a new card is plugged in.
		 */
		if (resource->size < min_size) {
			resource->size = min_size;
		}
	}
}

void cardbus_read_resources(device_t dev)
{
	resource_t moving_base, moving_limit, moving;
	unsigned long type;
	uint16_t ctl;
	
	/* See which bridge I/O resources are implemented */
	moving_base  = pci_moving_config32(dev, PCI_CB_IO_BASE_0);
	moving_limit = pci_moving_config32(dev, PCI_CB_IO_LIMIT_0);
	moving = moving_base & moving_limit;

	/* Initialize the io space constraints on the current bus */
	cardbus_record_bridge_resource(dev, moving, CARDBUS_IO_SIZE,
		PCI_CB_IO_BASE_0, IORESOURCE_IO);
	cardbus_size_bridge_resource(dev, PCI_CB_IO_BASE_0);

	/* See which bridge I/O resources are implemented */
	moving_base  = pci_moving_config32(dev, PCI_CB_IO_BASE_1);
	moving_limit = pci_moving_config32(dev, PCI_CB_IO_LIMIT_1);
	moving = moving_base & moving_limit;

	/* Initialize the io space constraints on the current bus */
	cardbus_record_bridge_resource(dev, moving, CARDBUS_IO_SIZE,
		PCI_CB_IO_BASE_1, IORESOURCE_IO);

	/* If I can enable prefetch for mem0 */
	ctl = pci_read_config16(dev, PCI_CB_BRIDGE_CONTROL);
	ctl &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
	ctl &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
	ctl |= PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
	pci_write_config16(dev, PCI_CB_BRIDGE_CONTROL, ctl);
	ctl = pci_read_config16(dev, PCI_CB_BRIDGE_CONTROL);

	/* See which bridge memory resources are implemented */
	moving_base  = pci_moving_config32(dev, PCI_CB_MEMORY_BASE_0);
	moving_limit = pci_moving_config32(dev, PCI_CB_MEMORY_LIMIT_0);
	moving = moving_base & moving_limit;

	/* Initialize the memory space constraints on the current bus */
	type = IORESOURCE_MEM;
	if (ctl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
		type |= IORESOURCE_PREFETCH;
	}
	cardbus_record_bridge_resource(dev, moving, CARDBUS_MEM_SIZE,
		PCI_CB_MEMORY_BASE_0, type);
	if (type & IORESOURCE_PREFETCH) {
		cardbus_size_bridge_resource(dev, PCI_CB_MEMORY_BASE_0);
	}

	/* See which bridge memory resources are implemented */
	moving_base  = pci_moving_config32(dev, PCI_CB_MEMORY_BASE_1);
	moving_limit = pci_moving_config32(dev, PCI_CB_MEMORY_LIMIT_1);
	moving = moving_base & moving_limit;

	/* Initialize the memory space constraints on the current bus */
	cardbus_record_bridge_resource(dev, moving, CARDBUS_MEM_SIZE,
		PCI_CB_MEMORY_BASE_1, IORESOURCE_MEM);
	cardbus_size_bridge_resource(dev, PCI_CB_MEMORY_BASE_1);

	compact_resources(dev);
}

void cardbus_enable_resources(device_t dev)
{
	uint16_t ctrl;
	ctrl = pci_read_config16(dev, PCI_CB_BRIDGE_CONTROL);
	ctrl |= (dev->link[0].bridge_ctrl & (
			PCI_BRIDGE_CTL_PARITY | 
			PCI_BRIDGE_CTL_SERR | 
			PCI_BRIDGE_CTL_NO_ISA |
			PCI_BRIDGE_CTL_VGA |
			PCI_BRIDGE_CTL_MASTER_ABORT |
			PCI_BRIDGE_CTL_BUS_RESET));
	ctrl |= (PCI_CB_BRIDGE_CTL_PARITY + PCI_CB_BRIDGE_CTL_SERR); /* error check */
	printk_debug("%s bridge ctrl <- %04x\n", dev_path(dev), ctrl);
	pci_write_config16(dev, PCI_BRIDGE_CONTROL, ctrl);

	pci_dev_enable_resources(dev);

	enable_childrens_resources(dev);
}

unsigned int cardbus_scan_bus(struct bus *bus, 
	unsigned min_devfn, unsigned max_devfn, 
	unsigned int max)
{
	return pci_scan_bus(bus, min_devfn, max_devfn, max);
}


unsigned int cardbus_scan_bridge(device_t dev, unsigned int max)
{
	struct bus *bus;
	uint32_t buses;
	uint16_t cr;

	printk_spew("%s for %s\n", __func__, dev_path(dev));

	bus = &dev->link[0];
	bus->dev = dev;
	dev->links = 1;

	/* Set up the primary, secondary and subordinate bus numbers. We have
	 * no idea how many buses are behind this bridge yet, so we set the
	 * subordinate bus number to 0xff for the moment. 
	 */
	bus->secondary = ++max;
	bus->subordinate = 0xff;

	/* Clear all status bits and turn off memory, I/O and master enables. */
	cr = pci_read_config16(dev, PCI_COMMAND);
	pci_write_config16(dev, PCI_COMMAND, 0x0000);
	pci_write_config16(dev, PCI_STATUS, 0xffff);

	/*
	 * Read the existing primary/secondary/subordinate bus
	 * number configuration.
	 */
	buses = pci_read_config32(dev, PCI_CB_PRIMARY_BUS);

	/* Configure the bus numbers for this bridge: the configuration
	 * transactions will not be propagated by the bridge if it is not
	 * correctly configured.
	 */
	buses &= 0xff000000;
	buses |= (((unsigned int) (dev->bus->secondary) << 0) |
		((unsigned int) (bus->secondary) << 8) |
		((unsigned int) (bus->subordinate) << 16));
	pci_write_config32(dev, PCI_CB_PRIMARY_BUS, buses);

	/* Now we can scan all subordinate buses 
	 * i.e. the bus behind the bridge.
	 */
	max = cardbus_scan_bus(bus, 0x00, 0xff, max);

	/* We know the number of buses behind this bridge. Set the subordinate
	 * bus number to its real value.
	 */
	bus->subordinate = max;
	buses = (buses & 0xff00ffff) |
		((unsigned int) (bus->subordinate) << 16);
	pci_write_config32(dev, PCI_CB_PRIMARY_BUS, buses);
	pci_write_config16(dev, PCI_COMMAND, cr);
	
	printk_spew("%s returns max %d\n", __func__, max);
	return max;
}

struct device_operations default_cardbus_ops_bus = {
	.read_resources   = cardbus_read_resources,
	.set_resources    = pci_dev_set_resources,
	.enable_resources = cardbus_enable_resources,
	.init		  = 0,
	.scan_bus	  = cardbus_scan_bridge,
	.enable           = 0,
	.reset_bus        = pci_bus_reset,
};