source: rtems-libbsd/freebsd/sys/arm/ti/ti_prcm.c @ bd3c01a

#include <machine/rtems-bsd-kernel-space.h>

/*
 * Copyright (c) 2010
 *      Ben Gray <ben.r.gray@gmail.com>.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Ben Gray.
 * 4. The name of the company nor the name of the author may be used to
 *    endorse or promote products derived from this software without specific
 *    prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY BEN GRAY ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL BEN GRAY BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * Power, Reset and Clock Management Module
 *
 * This is a very simple driver wrapper around the PRCM set of registers in
 * the OMAP3 chip. It allows you to turn on and off things like the functional
 * and interface clocks to the various on-chip modules.
 *
 */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <rtems/bsd/sys/resource.h>
#include <sys/rman.h>
#include <sys/lock.h>
#include <sys/mutex.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <machine/intr.h>

#include <arm/ti/ti_cpuid.h>
#include <arm/ti/ti_prcm.h>

/**
 *      ti_*_clk_devmap - Array of clock devices, should be defined one per SoC 
 *
 *      This array is typically defined in one of the targeted *_prcm_clk.c
 *      files and is specific to the given SoC platform.  Each entry in the array
 *      corresponds to an individual clock device.
 */
extern struct ti_clock_dev ti_omap4_clk_devmap[];
extern struct ti_clock_dev ti_am335x_clk_devmap[];

/**
 *      ti_prcm_clk_dev - returns a pointer to the clock device with given id
 *      @clk: the ID of the clock device to get
 *
 *      Simply iterates through the clk_devmap global array and returns a pointer
 *      to the clock device if found. 
 *
 *      LOCKING:
 *      None
 *
 *      RETURNS:
 *      The pointer to the clock device on success, on failure NULL is returned.
 */
static struct ti_clock_dev *
ti_prcm_clk_dev(clk_ident_t clk)
{
        struct ti_clock_dev *clk_dev;
        
        /* Find the clock within the devmap - it's a bit inefficent having a for 
         * loop for this, but this function should only called when a driver is 
         * being activated so IMHO not a big issue.
         */
        clk_dev = NULL;
        switch(ti_chip()) {
#ifdef SOC_OMAP4
        case CHIP_OMAP_4:
                clk_dev = &(ti_omap4_clk_devmap[0]);
                break;
#endif
#ifdef SOC_TI_AM335X
        case CHIP_AM335X:
                clk_dev = &(ti_am335x_clk_devmap[0]);
                break;
#endif
        }
        if (clk_dev == NULL)
                panic("No clock devmap found");
        while (clk_dev->id != INVALID_CLK_IDENT) {
                if (clk_dev->id == clk) {
                        return (clk_dev);
                }
                clk_dev++;
        }

        /* Sanity check we managed to find the clock */
        printf("ti_prcm: Failed to find clock device (%d)\n", clk);
        return (NULL);
}

/**
 *      ti_prcm_clk_valid - enables a clock for a particular module
 *      @clk: identifier for the module to enable, see ti_prcm.h for a list
 *            of possible modules.
 *               Example: OMAP3_MODULE_MMC1_ICLK or OMAP3_MODULE_GPTIMER10_FCLK.
 *      
 *      This function can enable either a functional or interface clock.
 *
 *      The real work done to enable the clock is really done in the callback
 *      function associated with the clock, this function is simply a wrapper
 *      around that.
 *
 *      LOCKING:
 *      Internally locks the driver context.
 *
 *      RETURNS:
 *      Returns 0 on success or positive error code on failure.
 */
int
ti_prcm_clk_valid(clk_ident_t clk)
{
        int ret = 0;

        if (ti_prcm_clk_dev(clk) == NULL)
                ret = EINVAL;
        
        return (ret);
}


/**
 *      ti_prcm_clk_enable - enables a clock for a particular module
 *      @clk: identifier for the module to enable, see ti_prcm.h for a list
 *            of possible modules.
 *               Example: OMAP3_MODULE_MMC1_ICLK or OMAP3_MODULE_GPTIMER10_FCLK.
 *      
 *      This function can enable either a functional or interface clock.
 *
 *      The real work done to enable the clock is really done in the callback
 *      function associated with the clock, this function is simply a wrapper
 *      around that.
 *
 *      LOCKING:
 *      Internally locks the driver context.
 *
 *      RETURNS:
 *      Returns 0 on success or positive error code on failure.
 */
int
ti_prcm_clk_enable(clk_ident_t clk)
{
        struct ti_clock_dev *clk_dev;
        int ret;

        /* Find the clock within the devmap - it's a bit inefficent having a for 
         * loop for this, but this function should only called when a driver is 
         * being activated so IMHO not a big issue.
         */
        clk_dev = ti_prcm_clk_dev(clk);

        /* Sanity check we managed to find the clock */
        if (clk_dev == NULL)
                return (EINVAL);

        /* Activate the clock */
        if (clk_dev->clk_activate)
                ret = clk_dev->clk_activate(clk_dev);
        else
                ret = EINVAL;

        return (ret);
}


/**
 *      ti_prcm_clk_disable - disables a clock for a particular module
 *      @clk: identifier for the module to enable, see ti_prcm.h for a list
 *            of possible modules.
 *               Example: OMAP3_MODULE_MMC1_ICLK or OMAP3_MODULE_GPTIMER10_FCLK.
 *      
 *      This function can enable either a functional or interface clock.
 *
 *      The real work done to enable the clock is really done in the callback
 *      function associated with the clock, this function is simply a wrapper
 *      around that.
 *
 *      LOCKING:
 *      Internally locks the driver context.
 *
 *      RETURNS:
 *      Returns 0 on success or positive error code on failure.
 */
int
ti_prcm_clk_disable(clk_ident_t clk)
{
        struct ti_clock_dev *clk_dev;
        int ret;

        /* Find the clock within the devmap - it's a bit inefficent having a for 
         * loop for this, but this function should only called when a driver is 
         * being activated so IMHO not a big issue.
         */
        clk_dev = ti_prcm_clk_dev(clk);

        /* Sanity check we managed to find the clock */
        if (clk_dev == NULL)
                return (EINVAL);

        /* Activate the clock */
        if (clk_dev->clk_deactivate)
                ret = clk_dev->clk_deactivate(clk_dev);
        else
                ret = EINVAL;
        
        return (ret);
}

/**
 *      ti_prcm_clk_set_source - sets the source 
 *      @clk: identifier for the module to enable, see ti_prcm.h for a list
 *            of possible modules.
 *               Example: OMAP3_MODULE_MMC1_ICLK or OMAP3_MODULE_GPTIMER10_FCLK.
 *      
 *      This function can enable either a functional or interface clock.
 *
 *      The real work done to enable the clock is really done in the callback
 *      function associated with the clock, this function is simply a wrapper
 *      around that.
 *
 *      LOCKING:
 *      Internally locks the driver context.
 *
 *      RETURNS:
 *      Returns 0 on success or positive error code on failure.
 */
int
ti_prcm_clk_set_source(clk_ident_t clk, clk_src_t clksrc)
{
        struct ti_clock_dev *clk_dev;
        int ret;

        /* Find the clock within the devmap - it's a bit inefficent having a for 
         * loop for this, but this function should only called when a driver is 
         * being activated so IMHO not a big issue.
         */
        clk_dev = ti_prcm_clk_dev(clk);

        /* Sanity check we managed to find the clock */
        if (clk_dev == NULL)
                return (EINVAL);

        /* Activate the clock */
        if (clk_dev->clk_set_source)
                ret = clk_dev->clk_set_source(clk_dev, clksrc);
        else
                ret = EINVAL;

        return (ret);
}


/**
 *      ti_prcm_clk_get_source_freq - gets the source clock frequency
 *      @clk: identifier for the module to enable, see ti_prcm.h for a list
 *            of possible modules.
 *      @freq: pointer to an integer that upon return will contain the src freq
 *
 *      This function returns the frequency of the source clock.
 *
 *      The real work done to enable the clock is really done in the callback
 *      function associated with the clock, this function is simply a wrapper
 *      around that.
 *
 *      LOCKING:
 *      Internally locks the driver context.
 *
 *      RETURNS:
 *      Returns 0 on success or positive error code on failure.
 */
int
ti_prcm_clk_get_source_freq(clk_ident_t clk, unsigned int *freq)
{
        struct ti_clock_dev *clk_dev;
        int ret;

        /* Find the clock within the devmap - it's a bit inefficent having a for 
         * loop for this, but this function should only called when a driver is 
         * being activated so IMHO not a big issue.
         */
        clk_dev = ti_prcm_clk_dev(clk);

        /* Sanity check we managed to find the clock */
        if (clk_dev == NULL)
                return (EINVAL);

        /* Get the source frequency of the clock */
        if (clk_dev->clk_get_source_freq)
                ret = clk_dev->clk_get_source_freq(clk_dev, freq);
        else
                ret = EINVAL;

        return (ret);
}

/**
 *      ti_prcm_clk_set_source_freq - sets the source clock frequency as close to freq as possible
 *      @clk: identifier for the module to enable, see ti_prcm.h for a list
 *            of possible modules.
 *      @freq: requested freq
 *
 *      LOCKING:
 *      Internally locks the driver context.
 *
 *      RETURNS:
 *      Returns 0 on success or positive error code on failure.
 */
int
ti_prcm_clk_set_source_freq(clk_ident_t clk, unsigned int freq)
{
        struct ti_clock_dev *clk_dev;
        int ret;

        clk_dev = ti_prcm_clk_dev(clk);

        /* Sanity check we managed to find the clock */
        if (clk_dev == NULL)
                return (EINVAL);

        /* Get the source frequency of the clock */
        if (clk_dev->clk_set_source_freq)
                ret = clk_dev->clk_set_source_freq(clk_dev, freq);
        else
                ret = EINVAL;

        return (ret);
}