clock3517.c
4.07 KB
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/*
* OMAP3517/3505-specific clock framework functions
*
* Copyright (C) 2010 Texas Instruments, Inc.
* Copyright (C) 2011 Nokia Corporation
*
* Ranjith Lohithakshan
* Paul Walmsley
*
* Parts of this code are based on code written by
* Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu,
* Russell King
*
* 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.
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/io.h>
#include "clock.h"
#include "clock3517.h"
#include "cm3xxx.h"
#include "cm-regbits-34xx.h"
/*
* In AM35xx IPSS, the {ICK,FCK} enable bits for modules are exported
* in the same register at a bit offset of 0x8. The EN_ACK for ICK is
* at an offset of 4 from ICK enable bit.
*/
#define AM35XX_IPSS_ICK_MASK 0xF
#define AM35XX_IPSS_ICK_EN_ACK_OFFSET 0x4
#define AM35XX_IPSS_ICK_FCK_OFFSET 0x8
#define AM35XX_IPSS_CLK_IDLEST_VAL 0
/**
* am35xx_clk_find_idlest - return clock ACK info for AM35XX IPSS
* @clk: struct clk * being enabled
* @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
* @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
* @idlest_val: pointer to a u8 to store the CM_IDLEST indicator
*
* The interface clocks on AM35xx IPSS reflects the clock idle status
* in the enable register itsel at a bit offset of 4 from the enable
* bit. A value of 1 indicates that clock is enabled.
*/
static void am35xx_clk_find_idlest(struct clk_hw_omap *clk,
void __iomem **idlest_reg,
u8 *idlest_bit,
u8 *idlest_val)
{
*idlest_reg = (__force void __iomem *)(clk->enable_reg);
*idlest_bit = clk->enable_bit + AM35XX_IPSS_ICK_EN_ACK_OFFSET;
*idlest_val = AM35XX_IPSS_CLK_IDLEST_VAL;
}
/**
* am35xx_clk_find_companion - find companion clock to @clk
* @clk: struct clk * to find the companion clock of
* @other_reg: void __iomem ** to return the companion clock CM_*CLKEN va in
* @other_bit: u8 ** to return the companion clock bit shift in
*
* Some clocks don't have companion clocks. For example, modules with
* only an interface clock (such as HECC) don't have a companion
* clock. Right now, this code relies on the hardware exporting a bit
* in the correct companion register that indicates that the
* nonexistent 'companion clock' is active. Future patches will
* associate this type of code with per-module data structures to
* avoid this issue, and remove the casts. No return value.
*/
static void am35xx_clk_find_companion(struct clk_hw_omap *clk,
void __iomem **other_reg,
u8 *other_bit)
{
*other_reg = (__force void __iomem *)(clk->enable_reg);
if (clk->enable_bit & AM35XX_IPSS_ICK_MASK)
*other_bit = clk->enable_bit + AM35XX_IPSS_ICK_FCK_OFFSET;
else
*other_bit = clk->enable_bit - AM35XX_IPSS_ICK_FCK_OFFSET;
}
const struct clk_hw_omap_ops clkhwops_am35xx_ipss_module_wait = {
.find_idlest = am35xx_clk_find_idlest,
.find_companion = am35xx_clk_find_companion,
};
/**
* am35xx_clk_ipss_find_idlest - return CM_IDLEST info for IPSS
* @clk: struct clk * being enabled
* @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
* @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
* @idlest_val: pointer to a u8 to store the CM_IDLEST indicator
*
* The IPSS target CM_IDLEST bit is at a different shift from the
* CM_{I,F}CLKEN bit. Pass back the correct info via @idlest_reg
* and @idlest_bit. No return value.
*/
static void am35xx_clk_ipss_find_idlest(struct clk_hw_omap *clk,
void __iomem **idlest_reg,
u8 *idlest_bit,
u8 *idlest_val)
{
u32 r;
r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
*idlest_reg = (__force void __iomem *)r;
*idlest_bit = AM35XX_ST_IPSS_SHIFT;
*idlest_val = OMAP34XX_CM_IDLEST_VAL;
}
const struct clk_hw_omap_ops clkhwops_am35xx_ipss_wait = {
.allow_idle = omap2_clkt_iclk_allow_idle,
.deny_idle = omap2_clkt_iclk_deny_idle,
.find_idlest = am35xx_clk_ipss_find_idlest,
.find_companion = omap2_clk_dflt_find_companion,
};