linux/drivers/gpu/drm/nouveau/nvkm/subdev/mxm/mxms.c

/*
 * Copyright 2012 Red Hat Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: Ben Skeggs
 */

#include <subdev/mxm.h>
#include "mxms.h"

#define ROM16(x) le16_to_cpu(*(u16 *)&(x))
#define ROM32(x) le32_to_cpu(*(u32 *)&(x))

static u8 *
mxms_data(struct nouveau_mxm *mxm)
{
	return mxm->mxms;

}

u16
mxms_version(struct nouveau_mxm *mxm)
{
	u8 *mxms = mxms_data(mxm);
	u16 version = (mxms[4] << 8) | mxms[5];
	switch (version ) {
	case 0x0200:
	case 0x0201:
	case 0x0300:
		return version;
	default:
		break;
	}

	nv_debug(mxm, "unknown version %d.%d\n", mxms[4], mxms[5]);
	return 0x0000;
}

u16
mxms_headerlen(struct nouveau_mxm *mxm)
{
	return 8;
}

u16
mxms_structlen(struct nouveau_mxm *mxm)
{
	return *(u16 *)&mxms_data(mxm)[6];
}

bool
mxms_checksum(struct nouveau_mxm *mxm)
{
	u16 size = mxms_headerlen(mxm) + mxms_structlen(mxm);
	u8 *mxms = mxms_data(mxm), sum = 0;
	while (size--)
		sum += *mxms++;
	if (sum) {
		nv_debug(mxm, "checksum invalid\n");
		return false;
	}
	return true;
}

bool
mxms_valid(struct nouveau_mxm *mxm)
{
	u8 *mxms = mxms_data(mxm);
	if (*(u32 *)mxms != 0x5f4d584d) {
		nv_debug(mxm, "signature invalid\n");
		return false;
	}

	if (!mxms_version(mxm) || !mxms_checksum(mxm))
		return false;

	return true;
}

bool
mxms_foreach(struct nouveau_mxm *mxm, u8 types,
	     bool (*exec)(struct nouveau_mxm *, u8 *, void *), void *info)
{
	u8 *mxms = mxms_data(mxm);
	u8 *desc = mxms + mxms_headerlen(mxm);
	u8 *fini = desc + mxms_structlen(mxm) - 1;
	while (desc < fini) {
		u8 type = desc[0] & 0x0f;
		u8 headerlen = 0;
		u8 recordlen = 0;
		u8 entries = 0;

		switch (type) {
		case 0: /* Output Device Structure */
			if (mxms_version(mxm) >= 0x0300)
				headerlen = 8;
			else
				headerlen = 6;
			break;
		case 1: /* System Cooling Capability Structure */
		case 2: /* Thermal Structure */
		case 3: /* Input Power Structure */
			headerlen = 4;
			break;
		case 4: /* GPIO Device Structure */
			headerlen = 4;
			recordlen = 2;
			entries   = (ROM32(desc[0]) & 0x01f00000) >> 20;
			break;
		case 5: /* Vendor Specific Structure */
			headerlen = 8;
			break;
		case 6: /* Backlight Control Structure */
			if (mxms_version(mxm) >= 0x0300) {
				headerlen = 4;
				recordlen = 8;
				entries   = (desc[1] & 0xf0) >> 4;
			} else {
				headerlen = 8;
			}
			break;
		case 7: /* Fan Control Structure */
			headerlen = 8;
			recordlen = 4;
			entries   = desc[1] & 0x07;
			break;
		default:
			nv_debug(mxm, "unknown descriptor type %d\n", type);
			return false;
		}

		if (nv_subdev(mxm)->debug >= NV_DBG_DEBUG && (exec == NULL)) {
			static const char * mxms_desc_name[] = {
				"ODS", "SCCS", "TS", "IPS",
				"GSD", "VSS", "BCS", "FCS",
			};
			u8 *dump = desc;
			int i, j;

			nv_debug(mxm, "%4s: ", mxms_desc_name[type]);
			for (j = headerlen - 1; j >= 0; j--)
				pr_cont("%02x", dump[j]);
			pr_cont("\n");
			dump += headerlen;

			for (i = 0; i < entries; i++, dump += recordlen) {
				nv_debug(mxm, "      ");
				for (j = recordlen - 1; j >= 0; j--)
					pr_cont("%02x", dump[j]);
				pr_cont("\n");
			}
		}

		if (types & (1 << type)) {
			if (!exec(mxm, desc, info))
				return false;
		}

		desc += headerlen + (entries * recordlen);
	}

	return true;
}

void
mxms_output_device(struct nouveau_mxm *mxm, u8 *pdata, struct mxms_odev *desc)
{
	u64 data = ROM32(pdata[0]);
	if (mxms_version(mxm) >= 0x0300)
		data |= (u64)ROM16(pdata[4]) << 32;

	desc->outp_type = (data & 0x00000000000000f0ULL) >> 4;
	desc->ddc_port  = (data & 0x0000000000000f00ULL) >> 8;
	desc->conn_type = (data & 0x000000000001f000ULL) >> 12;
	desc->dig_conn  = (data & 0x0000000000780000ULL) >> 19;
}