/*
 * Copyright (C) 2006-2007 PA Semi, Inc
 *
 * Author: Egor Martovetsky <egor@pasemi.com>
 * Maintained by: Olof Johansson <olof@lixom.net>
 *
 * Driver for the PWRficient onchip memory controllers
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */


#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/slab.h>
#include "edac_core.h"

#define MODULE_NAME "pasemi_edac"

#define MCCFG_MCEN				0x300
#define   MCCFG_MCEN_MMC_EN			0x00000001
#define MCCFG_ERRCOR				0x388
#define   MCCFG_ERRCOR_RNK_FAIL_DET_EN		0x00000100
#define   MCCFG_ERRCOR_ECC_GEN_EN		0x00000010
#define   MCCFG_ERRCOR_ECC_CRR_EN		0x00000001
#define MCCFG_SCRUB				0x384
#define   MCCFG_SCRUB_RGLR_SCRB_EN		0x00000001
#define MCDEBUG_ERRCTL1				0x728
#define   MCDEBUG_ERRCTL1_RFL_LOG_EN		0x00080000
#define   MCDEBUG_ERRCTL1_MBE_LOG_EN		0x00040000
#define   MCDEBUG_ERRCTL1_SBE_LOG_EN		0x00020000
#define MCDEBUG_ERRSTA				0x730
#define   MCDEBUG_ERRSTA_RFL_STATUS		0x00000004
#define   MCDEBUG_ERRSTA_MBE_STATUS		0x00000002
#define   MCDEBUG_ERRSTA_SBE_STATUS		0x00000001
#define MCDEBUG_ERRCNT1				0x734
#define   MCDEBUG_ERRCNT1_SBE_CNT_OVRFLO	0x00000080
#define MCDEBUG_ERRLOG1A			0x738
#define   MCDEBUG_ERRLOG1A_MERR_TYPE_M		0x30000000
#define   MCDEBUG_ERRLOG1A_MERR_TYPE_NONE	0x00000000
#define   MCDEBUG_ERRLOG1A_MERR_TYPE_SBE	0x10000000
#define   MCDEBUG_ERRLOG1A_MERR_TYPE_MBE	0x20000000
#define   MCDEBUG_ERRLOG1A_MERR_TYPE_RFL	0x30000000
#define   MCDEBUG_ERRLOG1A_MERR_BA_M		0x00700000
#define   MCDEBUG_ERRLOG1A_MERR_BA_S		20
#define   MCDEBUG_ERRLOG1A_MERR_CS_M		0x00070000
#define   MCDEBUG_ERRLOG1A_MERR_CS_S		16
#define   MCDEBUG_ERRLOG1A_SYNDROME_M		0x0000ffff
#define MCDRAM_RANKCFG				0x114
#define   MCDRAM_RANKCFG_EN			0x00000001
#define   MCDRAM_RANKCFG_TYPE_SIZE_M		0x000001c0
#define   MCDRAM_RANKCFG_TYPE_SIZE_S		6

#define PASEMI_EDAC_NR_CSROWS			8
#define PASEMI_EDAC_NR_CHANS			1
#define PASEMI_EDAC_ERROR_GRAIN			64

static int last_page_in_mmc;
static int system_mmc_id;


static u32 pasemi_edac_get_error_info(struct mem_ctl_info *mci)
{
	struct pci_dev *pdev = to_pci_dev(mci->dev);
	u32 tmp;

	pci_read_config_dword(pdev, MCDEBUG_ERRSTA,
			      &tmp);

	tmp &= (MCDEBUG_ERRSTA_RFL_STATUS | MCDEBUG_ERRSTA_MBE_STATUS
		| MCDEBUG_ERRSTA_SBE_STATUS);

	if (tmp) {
		if (tmp & MCDEBUG_ERRSTA_SBE_STATUS)
			pci_write_config_dword(pdev, MCDEBUG_ERRCNT1,
					       MCDEBUG_ERRCNT1_SBE_CNT_OVRFLO);
		pci_write_config_dword(pdev, MCDEBUG_ERRSTA, tmp);
	}

	return tmp;
}

static void pasemi_edac_process_error_info(struct mem_ctl_info *mci, u32 errsta)
{
	struct pci_dev *pdev = to_pci_dev(mci->dev);
	u32 errlog1a;
	u32 cs;

	if (!errsta)
		return;

	pci_read_config_dword(pdev, MCDEBUG_ERRLOG1A, &errlog1a);

	cs = (errlog1a & MCDEBUG_ERRLOG1A_MERR_CS_M) >>
		MCDEBUG_ERRLOG1A_MERR_CS_S;

	/* uncorrectable/multi-bit errors */
	if (errsta & (MCDEBUG_ERRSTA_MBE_STATUS |
		      MCDEBUG_ERRSTA_RFL_STATUS)) {
		edac_mc_handle_ue(mci, mci->csrows[cs].first_page, 0,
				  cs, mci->ctl_name);
	}

	/* correctable/single-bit errors */
	if (errsta & MCDEBUG_ERRSTA_SBE_STATUS) {
		edac_mc_handle_ce(mci, mci->csrows[cs].first_page, 0,
				  0, cs, 0, mci->ctl_name);
	}
}

static void pasemi_edac_check(struct mem_ctl_info *mci)
{
	u32 errsta;

	errsta = pasemi_edac_get_error_info(mci);
	if (errsta)
		pasemi_edac_process_error_info(mci, errsta);
}

static int pasemi_edac_init_csrows(struct mem_ctl_info *mci,
				   struct pci_dev *pdev,
				   enum edac_type edac_mode)
{
	struct csrow_info *csrow;
	u32 rankcfg;
	int index;

	for (index = 0; index < mci->nr_csrows; index++) {
		csrow = &mci->csrows[index];

		pci_read_config_dword(pdev,
				      MCDRAM_RANKCFG + (index * 12),
				      &rankcfg);

		if (!(rankcfg & MCDRAM_RANKCFG_EN))
			continue;

		switch ((rankcfg & MCDRAM_RANKCFG_TYPE_SIZE_M) >>
			MCDRAM_RANKCFG_TYPE_SIZE_S) {
		case 0:
			csrow->nr_pages = 128 << (20 - PAGE_SHIFT);
			break;
		case 1:
			csrow->nr_pages = 256 << (20 - PAGE_SHIFT);
			break;
		case 2:
		case 3:
			csrow->nr_pages = 512 << (20 - PAGE_SHIFT);
			break;
		case 4:
			csrow->nr_pages = 1024 << (20 - PAGE_SHIFT);
			break;
		case 5:
			csrow->nr_pages = 2048 << (20 - PAGE_SHIFT);
			break;
		default:
			edac_mc_printk(mci, KERN_ERR,
				"Unrecognized Rank Config. rankcfg=%u\n",
				rankcfg);
			return -EINVAL;
		}

		csrow->first_page = last_page_in_mmc;
		csrow->last_page = csrow->first_page + csrow->nr_pages - 1;
		last_page_in_mmc += csrow->nr_pages;
		csrow->page_mask = 0;
		csrow->grain = PASEMI_EDAC_ERROR_GRAIN;
		csrow->mtype = MEM_DDR;
		csrow->dtype = DEV_UNKNOWN;
		csrow->edac_mode = edac_mode;
	}
	return 0;
}

static int __devinit pasemi_edac_probe(struct pci_dev *pdev,
		const struct pci_device_id *ent)
{
	struct mem_ctl_info *mci = NULL;
	u32 errctl1, errcor, scrub, mcen;

	pci_read_config_dword(pdev, MCCFG_MCEN, &mcen);
	if (!(mcen & MCCFG_MCEN_MMC_EN))
		return -ENODEV;

	/*
	 * We should think about enabling other error detection later on
	 */

	pci_read_config_dword(pdev, MCDEBUG_ERRCTL1, &errctl1);
	errctl1 |= MCDEBUG_ERRCTL1_SBE_LOG_EN |
		MCDEBUG_ERRCTL1_MBE_LOG_EN |
		MCDEBUG_ERRCTL1_RFL_LOG_EN;
	pci_write_config_dword(pdev, MCDEBUG_ERRCTL1, errctl1);

	mci = edac_mc_alloc(0, PASEMI_EDAC_NR_CSROWS, PASEMI_EDAC_NR_CHANS,
				system_mmc_id++);

	if (mci == NULL)
		return -ENOMEM;

	pci_read_config_dword(pdev, MCCFG_ERRCOR, &errcor);
	errcor |= MCCFG_ERRCOR_RNK_FAIL_DET_EN |
		MCCFG_ERRCOR_ECC_GEN_EN |
		MCCFG_ERRCOR_ECC_CRR_EN;

	mci->dev = &pdev->dev;
	mci->mtype_cap = MEM_FLAG_DDR | MEM_FLAG_RDDR;
	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_EC | EDAC_FLAG_SECDED;
	mci->edac_cap = (errcor & MCCFG_ERRCOR_ECC_GEN_EN) ?
		((errcor & MCCFG_ERRCOR_ECC_CRR_EN) ?
		 (EDAC_FLAG_EC | EDAC_FLAG_SECDED) : EDAC_FLAG_EC) :
		EDAC_FLAG_NONE;
	mci->mod_name = MODULE_NAME;
	mci->dev_name = pci_name(pdev);
	mci->ctl_name = "pasemi,1682m-mc";
	mci->edac_check = pasemi_edac_check;
	mci->ctl_page_to_phys = NULL;
	pci_read_config_dword(pdev, MCCFG_SCRUB, &scrub);
	mci->scrub_cap = SCRUB_FLAG_HW_PROG | SCRUB_FLAG_HW_SRC;
	mci->scrub_mode =
		((errcor & MCCFG_ERRCOR_ECC_CRR_EN) ? SCRUB_FLAG_HW_SRC : 0) |
		((scrub & MCCFG_SCRUB_RGLR_SCRB_EN) ? SCRUB_FLAG_HW_PROG : 0);

	if (pasemi_edac_init_csrows(mci, pdev,
				    (mci->edac_cap & EDAC_FLAG_SECDED) ?
				    EDAC_SECDED :
				    ((mci->edac_cap & EDAC_FLAG_EC) ?
				     EDAC_EC : EDAC_NONE)))
		goto fail;

	/*
	 * Clear status
	 */
	pasemi_edac_get_error_info(mci);

	if (edac_mc_add_mc(mci))
		goto fail;

	/* get this far and it's successful */
	return 0;

fail:
	edac_mc_free(mci);
	return -ENODEV;
}

static void __devexit pasemi_edac_remove(struct pci_dev *pdev)
{
	struct mem_ctl_info *mci = edac_mc_del_mc(&pdev->dev);

	if (!mci)
		return;

	edac_mc_free(mci);
}


static const struct pci_device_id pasemi_edac_pci_tbl[] = {
	{ PCI_DEVICE(PCI_VENDOR_ID_PASEMI, 0xa00a) },
};

MODULE_DEVICE_TABLE(pci, pasemi_edac_pci_tbl);

static struct pci_driver pasemi_edac_driver = {
	.name = MODULE_NAME,
	.probe = pasemi_edac_probe,
	.remove = __devexit_p(pasemi_edac_remove),
	.id_table = pasemi_edac_pci_tbl,
};

static int __init pasemi_edac_init(void)
{
	return pci_register_driver(&pasemi_edac_driver);
}

static void __exit pasemi_edac_exit(void)
{
	pci_unregister_driver(&pasemi_edac_driver);
}

module_init(pasemi_edac_init);
module_exit(pasemi_edac_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>");
MODULE_DESCRIPTION("MC support for PA Semi PA6T-1682M memory controller");