linux-imx

/*

 *

 *  Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>

 *

 * 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.

 *

 */

​

#include <linux/clk-provider.h>

#include <linux/err.h>

#include <linux/io.h>

#include <linux/of.h>

#include <linux/of_address.h>

​

#define MHZ (1000 * 1000)

​

#define BASE_CPU_SHIFT      1

#define BASE_CPU_MASK       0x7F

​

#define CPU_AHB_SHIFT       12

#define CPU_AHB_MASK        0x07

​

#define FIXED_BASE_SHIFT    8

#define FIXED_BASE_MASK     0x01

​

#define CLASSIC_BASE_SHIFT  16

#define CLASSIC_BASE_MASK   0x1F

​

#define CX_BASE_SHIFT       15

#define CX_BASE_MASK        0x3F

​

#define CX_UNKNOWN_SHIFT    21

#define CX_UNKNOWN_MASK     0x03

​

struct nspire_clk_info {

    u32 base_clock;

    u16 base_cpu_ratio;

    u16 base_ahb_ratio;

};

​

​

#define EXTRACT(var, prop) (((var)>>prop##_SHIFT) & prop##_MASK)

static void nspire_clkinfo_cx(u32 val, struct nspire_clk_info *clk)

{

    if (EXTRACT(val, FIXED_BASE))

        clk->base_clock = 48 * MHZ;

    else

        clk->base_clock = 6 * EXTRACT(val, CX_BASE) * MHZ;

​

    clk->base_cpu_ratio = EXTRACT(val, BASE_CPU) * EXTRACT(val, CX_UNKNOWN);

    clk->base_ahb_ratio = clk->base_cpu_ratio * (EXTRACT(val, CPU_AHB) + 1);

}

​

static void nspire_clkinfo_classic(u32 val, struct nspire_clk_info *clk)

{

    if (EXTRACT(val, FIXED_BASE))

        clk->base_clock = 27 * MHZ;

    else

        clk->base_clock = (300 - 6 * EXTRACT(val, CLASSIC_BASE)) * MHZ;

​

    clk->base_cpu_ratio = EXTRACT(val, BASE_CPU) * 2;