FreeBSD/Linux Kernel Cross Reference
sys/arm/ti/ti_prcm.c

     /*
      * 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 Managment 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: releng/10.2/sys/arm/ti/ti_prcm.c 259329 2013-12-13 20:43:11Z ian $");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    #include <sys/bus.h>
    #include <sys/resource.h>
    #include <sys/rman.h>
    #include <sys/lock.h>
    #include <sys/mutex.h>
    
    #include <machine/bus.h>
    #include <machine/cpu.h>
    #include <machine/cpufunc.h>
    #include <machine/resource.h>
    #include <machine/intr.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_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 = &(ti_clk_devmap[0]);
            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);
   }

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