freebsd-dev/sys/arm/ti/ti_prcm.c

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/*
* 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("$FreeBSD$");
#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/frame.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);
}