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clk.c

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
 */

#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <bcm63xx_cpu.h>
#include <bcm63xx_io.h>
#include <bcm63xx_regs.h>
#include <bcm63xx_clk.h>

static DEFINE_MUTEX(clocks_mutex);


static void clk_enable_unlocked(struct clk *clk)
{
      if (clk->set && (clk->usage++) == 0)
            clk->set(clk, 1);
}

static void clk_disable_unlocked(struct clk *clk)
{
      if (clk->set && (--clk->usage) == 0)
            clk->set(clk, 0);
}

static void bcm_hwclock_set(u32 mask, int enable)
{
      u32 reg;

      reg = bcm_perf_readl(PERF_CKCTL_REG);
      if (enable)
            reg |= mask;
      else
            reg &= ~mask;
      bcm_perf_writel(reg, PERF_CKCTL_REG);
}

/*
 * Ethernet MAC "misc" clock: dma clocks and main clock on 6348
 */
static void enet_misc_set(struct clk *clk, int enable)
{
      u32 mask;

      if (BCMCPU_IS_6338())
            mask = CKCTL_6338_ENET_EN;
      else if (BCMCPU_IS_6345())
            mask = CKCTL_6345_ENET_EN;
      else if (BCMCPU_IS_6348())
            mask = CKCTL_6348_ENET_EN;
      else
            /* BCMCPU_IS_6358 */
            mask = CKCTL_6358_EMUSB_EN;
      bcm_hwclock_set(mask, enable);
}

static struct clk clk_enet_misc = {
      .set  = enet_misc_set,
};

/*
 * Ethernet MAC clocks: only revelant on 6358, silently enable misc
 * clocks
 */
static void enetx_set(struct clk *clk, int enable)
{
      if (enable)
            clk_enable_unlocked(&clk_enet_misc);
      else
            clk_disable_unlocked(&clk_enet_misc);

      if (BCMCPU_IS_6358()) {
            u32 mask;

            if (clk->id == 0)
                  mask = CKCTL_6358_ENET0_EN;
            else
                  mask = CKCTL_6358_ENET1_EN;
            bcm_hwclock_set(mask, enable);
      }
}

static struct clk clk_enet0 = {
      .id   = 0,
      .set  = enetx_set,
};

static struct clk clk_enet1 = {
      .id   = 1,
      .set  = enetx_set,
};

/*
 * Ethernet PHY clock
 */
static void ephy_set(struct clk *clk, int enable)
{
      if (!BCMCPU_IS_6358())
            return;
      bcm_hwclock_set(CKCTL_6358_EPHY_EN, enable);
}


static struct clk clk_ephy = {
      .set  = ephy_set,
};

/*
 * PCM clock
 */
static void pcm_set(struct clk *clk, int enable)
{
      if (!BCMCPU_IS_6358())
            return;
      bcm_hwclock_set(CKCTL_6358_PCM_EN, enable);
}

static struct clk clk_pcm = {
      .set  = pcm_set,
};

/*
 * USB host clock
 */
static void usbh_set(struct clk *clk, int enable)
{
      if (!BCMCPU_IS_6348())
            return;
      bcm_hwclock_set(CKCTL_6348_USBH_EN, enable);
}

static struct clk clk_usbh = {
      .set  = usbh_set,
};

/*
 * SPI clock
 */
static void spi_set(struct clk *clk, int enable)
{
      u32 mask;

      if (BCMCPU_IS_6338())
            mask = CKCTL_6338_SPI_EN;
      else if (BCMCPU_IS_6348())
            mask = CKCTL_6348_SPI_EN;
      else
            /* BCMCPU_IS_6358 */
            mask = CKCTL_6358_SPI_EN;
      bcm_hwclock_set(mask, enable);
}

static struct clk clk_spi = {
      .set  = spi_set,
};

/*
 * Internal peripheral clock
 */
static struct clk clk_periph = {
      .rate = (50 * 1000 * 1000),
};


/*
 * Linux clock API implementation
 */
int clk_enable(struct clk *clk)
{
      mutex_lock(&clocks_mutex);
      clk_enable_unlocked(clk);
      mutex_unlock(&clocks_mutex);
      return 0;
}

EXPORT_SYMBOL(clk_enable);

void clk_disable(struct clk *clk)
{
      mutex_lock(&clocks_mutex);
      clk_disable_unlocked(clk);
      mutex_unlock(&clocks_mutex);
}

EXPORT_SYMBOL(clk_disable);

unsigned long clk_get_rate(struct clk *clk)
{
      return clk->rate;
}

EXPORT_SYMBOL(clk_get_rate);

struct clk *clk_get(struct device *dev, const char *id)
{
      if (!strcmp(id, "enet0"))
            return &clk_enet0;
      if (!strcmp(id, "enet1"))
            return &clk_enet1;
      if (!strcmp(id, "ephy"))
            return &clk_ephy;
      if (!strcmp(id, "usbh"))
            return &clk_usbh;
      if (!strcmp(id, "spi"))
            return &clk_spi;
      if (!strcmp(id, "periph"))
            return &clk_periph;
      if (BCMCPU_IS_6358() && !strcmp(id, "pcm"))
            return &clk_pcm;
      return ERR_PTR(-ENOENT);
}

EXPORT_SYMBOL(clk_get);

void clk_put(struct clk *clk)
{
}

EXPORT_SYMBOL(clk_put);

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