xref: /openbmc/linux/drivers/tc/tc.c (revision 4bdc0d67)

/*
 *	TURBOchannel bus services.
 *
 *	Copyright (c) Harald Koerfgen, 1998
 *	Copyright (c) 2001, 2003, 2005, 2006, 2018  Maciej W. Rozycki
 *	Copyright (c) 2005  James Simmons
 *
 *	This file is subject to the terms and conditions of the GNU
 *	General Public License.  See the file "COPYING" in the main
 *	directory of this archive for more details.
 */
#include <linux/compiler.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/tc.h>
#include <linux/types.h>

#include <asm/io.h>

static struct tc_bus tc_bus = {
	.name = "TURBOchannel",
};

/*
 * Probing for TURBOchannel modules.
 */
static void __init tc_bus_add_devices(struct tc_bus *tbus)
{
	resource_size_t slotsize = tbus->info.slot_size << 20;
	resource_size_t extslotsize = tbus->ext_slot_size;
	resource_size_t slotaddr;
	resource_size_t extslotaddr;
	resource_size_t devsize;
	void __iomem *module;
	struct tc_dev *tdev;
	int i, slot, err;
	u8 pattern[4];
	long offset;

	for (slot = 0; slot < tbus->num_tcslots; slot++) {
		slotaddr = tbus->slot_base + slot * slotsize;
		extslotaddr = tbus->ext_slot_base + slot * extslotsize;
		module = ioremap(slotaddr, slotsize);
		BUG_ON(!module);

		offset = TC_OLDCARD;

		err = 0;
		err |= tc_preadb(pattern + 0, module + offset + TC_PATTERN0);
		err |= tc_preadb(pattern + 1, module + offset + TC_PATTERN1);
		err |= tc_preadb(pattern + 2, module + offset + TC_PATTERN2);
		err |= tc_preadb(pattern + 3, module + offset + TC_PATTERN3);
		if (err)
			goto out_err;

		if (pattern[0] != 0x55 || pattern[1] != 0x00 ||
		    pattern[2] != 0xaa || pattern[3] != 0xff) {
			offset = TC_NEWCARD;

			err = 0;
			err |= tc_preadb(pattern + 0,
					 module + offset + TC_PATTERN0);
			err |= tc_preadb(pattern + 1,
					 module + offset + TC_PATTERN1);
			err |= tc_preadb(pattern + 2,
					 module + offset + TC_PATTERN2);
			err |= tc_preadb(pattern + 3,
					 module + offset + TC_PATTERN3);
			if (err)
				goto out_err;
		}

		if (pattern[0] != 0x55 || pattern[1] != 0x00 ||
		    pattern[2] != 0xaa || pattern[3] != 0xff)
			goto out_err;

		/* Found a board, allocate it an entry in the list */
		tdev = kzalloc(sizeof(*tdev), GFP_KERNEL);
		if (!tdev) {
			pr_err("tc%x: unable to allocate tc_dev\n", slot);
			goto out_err;
		}
		dev_set_name(&tdev->dev, "tc%x", slot);
		tdev->bus = tbus;
		tdev->dev.parent = &tbus->dev;
		tdev->dev.bus = &tc_bus_type;
		tdev->slot = slot;

		/* TURBOchannel has 34-bit DMA addressing (16GiB space). */
		tdev->dma_mask = DMA_BIT_MASK(34);
		tdev->dev.dma_mask = &tdev->dma_mask;
		tdev->dev.coherent_dma_mask = DMA_BIT_MASK(34);

		for (i = 0; i < 8; i++) {
			tdev->firmware[i] =
				readb(module + offset + TC_FIRM_VER + 4 * i);
			tdev->vendor[i] =
				readb(module + offset + TC_VENDOR + 4 * i);
			tdev->name[i] =
				readb(module + offset + TC_MODULE + 4 * i);
		}
		tdev->firmware[8] = 0;
		tdev->vendor[8] = 0;
		tdev->name[8] = 0;

		pr_info("%s: %s %s %s\n", dev_name(&tdev->dev), tdev->vendor,
			tdev->name, tdev->firmware);

		devsize = readb(module + offset + TC_SLOT_SIZE);
		devsize <<= 22;
		if (devsize <= slotsize) {
			tdev->resource.start = slotaddr;
			tdev->resource.end = slotaddr + devsize - 1;
		} else if (devsize <= extslotsize) {
			tdev->resource.start = extslotaddr;
			tdev->resource.end = extslotaddr + devsize - 1;
		} else {
			pr_err("%s: Cannot provide slot space "
			       "(%ldMiB required, up to %ldMiB supported)\n",
			       dev_name(&tdev->dev), (long)(devsize >> 20),
			       (long)(max(slotsize, extslotsize) >> 20));
			kfree(tdev);
			goto out_err;
		}
		tdev->resource.name = tdev->name;
		tdev->resource.flags = IORESOURCE_MEM;

		tc_device_get_irq(tdev);

		if (device_register(&tdev->dev)) {
			put_device(&tdev->dev);
			goto out_err;
		}
		list_add_tail(&tdev->node, &tbus->devices);

out_err:
		iounmap(module);
	}
}

/*
 * The main entry.
 */
static int __init tc_init(void)
{
	/* Initialize the TURBOchannel bus */
	if (tc_bus_get_info(&tc_bus))
		goto out_err;

	INIT_LIST_HEAD(&tc_bus.devices);
	dev_set_name(&tc_bus.dev, "tc");
	if (device_register(&tc_bus.dev))
		goto out_err_device;

	if (tc_bus.info.slot_size) {
		unsigned int tc_clock = tc_get_speed(&tc_bus) / 100000;

		pr_info("tc: TURBOchannel rev. %d at %d.%d MHz "
			"(with%s parity)\n", tc_bus.info.revision,
			tc_clock / 10, tc_clock % 10,
			tc_bus.info.parity ? "" : "out");

		tc_bus.resource[0].start = tc_bus.slot_base;
		tc_bus.resource[0].end = tc_bus.slot_base +
					 (tc_bus.info.slot_size << 20) *
					 tc_bus.num_tcslots - 1;
		tc_bus.resource[0].name = tc_bus.name;
		tc_bus.resource[0].flags = IORESOURCE_MEM;
		if (request_resource(&iomem_resource,
				     &tc_bus.resource[0]) < 0) {
			pr_err("tc: Cannot reserve resource\n");
			goto out_err_device;
		}
		if (tc_bus.ext_slot_size) {
			tc_bus.resource[1].start = tc_bus.ext_slot_base;
			tc_bus.resource[1].end = tc_bus.ext_slot_base +
						 tc_bus.ext_slot_size *
						 tc_bus.num_tcslots - 1;
			tc_bus.resource[1].name = tc_bus.name;
			tc_bus.resource[1].flags = IORESOURCE_MEM;
			if (request_resource(&iomem_resource,
					     &tc_bus.resource[1]) < 0) {
				pr_err("tc: Cannot reserve resource\n");
				goto out_err_resource;
			}
		}

		tc_bus_add_devices(&tc_bus);
	}

	return 0;

out_err_resource:
	release_resource(&tc_bus.resource[0]);
out_err_device:
	put_device(&tc_bus.dev);
out_err:
	return 0;
}

subsys_initcall(tc_init);