linux-imx

/*

 * SCOM FSI Client device driver

 *

 * Copyright (C) IBM Corporation 2016

 *

 * 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

 * MERGCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

​

#include <linux/fsi.h>

#include <linux/module.h>

#include <linux/cdev.h>

#include <linux/delay.h>

#include <linux/fs.h>

#include <linux/uaccess.h>

#include <linux/slab.h>

#include <linux/list.h>

​

#include <uapi/linux/fsi.h>

​

#define FSI_ENGID_SCOM      0x5

​

/* SCOM engine register set */

#define SCOM_DATA0_REG      0x00

#define SCOM_DATA1_REG      0x04

#define SCOM_CMD_REG        0x08

#define SCOM_FSI2PIB_RESET_REG  0x18

#define SCOM_STATUS_REG     0x1C /* Read */

#define SCOM_PIB_RESET_REG  0x1C /* Write */

​

/* Command register */

#define SCOM_WRITE_CMD      0x80000000

#define SCOM_READ_CMD       0x00000000

​

/* Status register bits */

#define SCOM_STATUS_ERR_SUMMARY     0x80000000

#define SCOM_STATUS_PROTECTION      0x01000000

#define SCOM_STATUS_PARITY      0x04000000

#define SCOM_STATUS_PIB_ABORT       0x00100000

#define SCOM_STATUS_PIB_RESP_MASK   0x00007000

#define SCOM_STATUS_PIB_RESP_SHIFT  12

​

#define SCOM_STATUS_ANY_ERR     (SCOM_STATUS_ERR_SUMMARY | \

                     SCOM_STATUS_PROTECTION | \

                     SCOM_STATUS_PARITY |     \

                     SCOM_STATUS_PIB_ABORT | \

                     SCOM_STATUS_PIB_RESP_MASK)

/* SCOM address encodings */

#define XSCOM_ADDR_IND_FLAG     BIT_ULL(63)

#define XSCOM_ADDR_INF_FORM1        BIT_ULL(60)

​

/* SCOM indirect stuff */

#define XSCOM_ADDR_DIRECT_PART      0x7fffffffull

#define XSCOM_ADDR_INDIRECT_PART    0x000fffff00000000ull

#define XSCOM_DATA_IND_READ     BIT_ULL(63)

#define XSCOM_DATA_IND_COMPLETE     BIT_ULL(31)

#define XSCOM_DATA_IND_ERR_MASK     0x70000000ull

#define XSCOM_DATA_IND_ERR_SHIFT    28

#define XSCOM_DATA_IND_DATA     0x0000ffffull

#define XSCOM_DATA_IND_FORM1_DATA   0x000fffffffffffffull

#define XSCOM_ADDR_FORM1_LOW        0x000ffffffffull

#define XSCOM_ADDR_FORM1_HI     0xfff00000000ull

#define XSCOM_ADDR_FORM1_HI_SHIFT   20

​

/* Retries */

#define SCOM_MAX_RETRIES        100 /* Retries on busy */

#define SCOM_MAX_IND_RETRIES        10  /* Retries indirect not ready */

​

struct scom_device {

    struct list_head link;

    struct fsi_device *fsi_dev;

    struct device dev;

    struct cdev cdev;

    struct mutex lock;

    bool dead;

};

​

static int __put_scom(struct scom_device *scom_dev, uint64_t value,

              uint32_t addr, uint32_t *status)

{

    __be32 data, raw_status;

    int rc;

​

    data = cpu_to_be32((value >> 32) & 0xffffffff);

    rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA0_REG, &data,

                sizeof(uint32_t));