linux-imx

/*

 * Clock driver for Keystone 2 based devices

 *

 * Copyright (C) 2013 Texas Instruments.

 *  Murali Karicheri <m-karicheri2@ti.com>

 *  Santosh Shilimkar <santosh.shilimkar@ti.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 */

#include <linux/clk-provider.h>

#include <linux/err.h>

#include <linux/io.h>

#include <linux/slab.h>

#include <linux/of_address.h>

#include <linux/of.h>

#include <linux/module.h>

​

/* PSC register offsets */

#define PTCMD           0x120

#define PTSTAT          0x128

#define PDSTAT          0x200

#define PDCTL           0x300

#define MDSTAT          0x800

#define MDCTL           0xa00

​

/* PSC module states */

#define PSC_STATE_SWRSTDISABLE  0

#define PSC_STATE_SYNCRST   1

#define PSC_STATE_DISABLE   2

#define PSC_STATE_ENABLE    3

​

#define MDSTAT_STATE_MASK   0x3f

#define MDSTAT_MCKOUT       BIT(12)

#define PDSTAT_STATE_MASK   0x1f

#define MDCTL_FORCE     BIT(31)

#define MDCTL_LRESET        BIT(8)

#define PDCTL_NEXT      BIT(0)

​

/* Maximum timeout to bail out state transition for module */

#define STATE_TRANS_MAX_COUNT   0xffff

​

static void __iomem *domain_transition_base;

​

/**

 * struct clk_psc_data - PSC data

 * @control_base: Base address for a PSC control

 * @domain_base: Base address for a PSC domain

 * @domain_id: PSC domain id number

 */

struct clk_psc_data {

    void __iomem *control_base;

    void __iomem *domain_base;

    u32 domain_id;

};

​

/**

 * struct clk_psc - PSC clock structure

 * @hw: clk_hw for the psc

 * @psc_data: PSC driver specific data

 * @lock: Spinlock used by the driver

 */

struct clk_psc {

    struct clk_hw hw;

    struct clk_psc_data *psc_data;

    spinlock_t *lock;

};

​

static DEFINE_SPINLOCK(psc_lock);

​

#define to_clk_psc(_hw) container_of(_hw, struct clk_psc, hw)

​

static void psc_config(void __iomem *control_base, void __iomem *domain_base,

                        u32 next_state, u32 domain_id)

{

    u32 ptcmd, pdstat, pdctl, mdstat, mdctl, ptstat;

    u32 count = STATE_TRANS_MAX_COUNT;

​

    mdctl = readl(control_base + MDCTL);

    mdctl &= ~MDSTAT_STATE_MASK;

    mdctl |= next_state;

    /* For disable, we always put the module in local reset */

    if (next_state == PSC_STATE_DISABLE)

        mdctl &= ~MDCTL_LRESET;

    writel(mdctl, control_base + MDCTL);

​

    pdstat = readl(domain_base + PDSTAT);

    if (!(pdstat & PDSTAT_STATE_MASK)) {

        pdctl = readl(domain_base + PDCTL);

        pdctl |= PDCTL_NEXT;