linux-imx

/*

 * 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.

 *

 * Copyright (C) 2014 ARM Limited

 */

​

#include <linux/delay.h>

#include <linux/err.h>

#include <linux/io.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/sched/signal.h>

#include <linux/slab.h>

#include <linux/syscore_ops.h>

#include <linux/vexpress.h>

​

​

#define SYS_CFGDATA     0x0

​

#define SYS_CFGCTRL     0x4

#define SYS_CFGCTRL_START   (1 << 31)

#define SYS_CFGCTRL_WRITE   (1 << 30)

#define SYS_CFGCTRL_DCC(n)  (((n) & 0xf) << 26)

#define SYS_CFGCTRL_FUNC(n) (((n) & 0x3f) << 20)

#define SYS_CFGCTRL_SITE(n) (((n) & 0x3) << 16)

#define SYS_CFGCTRL_POSITION(n) (((n) & 0xf) << 12)

#define SYS_CFGCTRL_DEVICE(n)   (((n) & 0xfff) << 0)

​

#define SYS_CFGSTAT     0x8

#define SYS_CFGSTAT_ERR     (1 << 1)

#define SYS_CFGSTAT_COMPLETE    (1 << 0)

​

​

struct vexpress_syscfg {

    struct device *dev;

    void __iomem *base;

    struct list_head funcs;

};

​

struct vexpress_syscfg_func {

    struct list_head list;

    struct vexpress_syscfg *syscfg;

    struct regmap *regmap;

    int num_templates;

    u32 template[0]; /* Keep it last! */

};

​

​

static int vexpress_syscfg_exec(struct vexpress_syscfg_func *func,

        int index, bool write, u32 *data)

{

    struct vexpress_syscfg *syscfg = func->syscfg;

    u32 command, status;

    int tries;

    long timeout;

​

    if (WARN_ON(index >= func->num_templates))

        return -EINVAL;

​

    command = readl(syscfg->base + SYS_CFGCTRL);

    if (WARN_ON(command & SYS_CFGCTRL_START))

        return -EBUSY;

​

    command = func->template[index];

    command |= SYS_CFGCTRL_START;

    command |= write ? SYS_CFGCTRL_WRITE : 0;

​

    /* Use a canary for reads */

    if (!write)

        *data = 0xdeadbeef;

​

    dev_dbg(syscfg->dev, "func %p, command %x, data %x\n",

            func, command, *data);

    writel(*data, syscfg->base + SYS_CFGDATA);

    writel(0, syscfg->base + SYS_CFGSTAT);

    writel(command, syscfg->base + SYS_CFGCTRL);

    mb();

​

    /* The operation can take ages... Go to sleep, 100us initially */

    tries = 100;

    timeout = 100;

    do {

        if (!irqs_disabled()) {

            set_current_state(TASK_INTERRUPTIBLE);

            schedule_timeout(usecs_to_jiffies(timeout));