LXR linux/arch/arm/mach-omap2/clock3517.c

   1/*
   2 * OMAP3517/3505-specific clock framework functions
   3 *
   4 * Copyright (C) 2010 Texas Instruments, Inc.
   5 * Copyright (C) 2011 Nokia Corporation
   6 *
   7 * Ranjith Lohithakshan
   8 * Paul Walmsley
   9 *
  10 * Parts of this code are based on code written by
  11 * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu,
  12 * Russell King
  13 *
  14 * This program is free software; you can redistribute it and/or modify
  15 * it under the terms of the GNU General Public License version 2 as
  16 * published by the Free Software Foundation.
  17 */
  18#undef DEBUG
  19
  20#include <linux/kernel.h>
  21#include <linux/clk.h>
  22#include <linux/io.h>
  23
  24#include <plat/clock.h>
  25
  26#include "clock.h"
  27#include "clock3517.h"
  28#include "cm2xxx_3xxx.h"
  29#include "cm-regbits-34xx.h"
  30
  31/*
  32 * In AM35xx IPSS, the {ICK,FCK} enable bits for modules are exported
  33 * in the same register at a bit offset of 0x8. The EN_ACK for ICK is
  34 * at an offset of 4 from ICK enable bit.
  35 */
  36#define AM35XX_IPSS_ICK_MASK                    0xF
  37#define AM35XX_IPSS_ICK_EN_ACK_OFFSET           0x4
  38#define AM35XX_IPSS_ICK_FCK_OFFSET              0x8
  39#define AM35XX_IPSS_CLK_IDLEST_VAL              0
  40
  41/**
  42 * am35xx_clk_find_idlest - return clock ACK info for AM35XX IPSS
  43 * @clk: struct clk * being enabled
  44 * @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
  45 * @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
  46 * @idlest_val: pointer to a u8 to store the CM_IDLEST indicator
  47 *
  48 * The interface clocks on AM35xx IPSS reflects the clock idle status
  49 * in the enable register itsel at a bit offset of 4 from the enable
  50 * bit. A value of 1 indicates that clock is enabled.
  51 */
  52static void am35xx_clk_find_idlest(struct clk *clk,
  53                                            void __iomem **idlest_reg,
  54                                            u8 *idlest_bit,
  55                                            u8 *idlest_val)
  56{
  57        *idlest_reg = (__force void __iomem *)(clk->enable_reg);
  58        *idlest_bit = clk->enable_bit + AM35XX_IPSS_ICK_EN_ACK_OFFSET;
  59        *idlest_val = AM35XX_IPSS_CLK_IDLEST_VAL;
  60}
  61
  62/**
  63 * am35xx_clk_find_companion - find companion clock to @clk
  64 * @clk: struct clk * to find the companion clock of
  65 * @other_reg: void __iomem ** to return the companion clock CM_*CLKEN va in
  66 * @other_bit: u8 ** to return the companion clock bit shift in
  67 *
  68 * Some clocks don't have companion clocks.  For example, modules with
  69 * only an interface clock (such as HECC) don't have a companion
  70 * clock.  Right now, this code relies on the hardware exporting a bit
  71 * in the correct companion register that indicates that the
  72 * nonexistent 'companion clock' is active.  Future patches will
  73 * associate this type of code with per-module data structures to
  74 * avoid this issue, and remove the casts.  No return value.
  75 */
  76static void am35xx_clk_find_companion(struct clk *clk, void __iomem **other_reg,
  77                                            u8 *other_bit)
  78{
  79        *other_reg = (__force void __iomem *)(clk->enable_reg);
  80        if (clk->enable_bit & AM35XX_IPSS_ICK_MASK)
  81                *other_bit = clk->enable_bit + AM35XX_IPSS_ICK_FCK_OFFSET;
  82        else
  83                *other_bit = clk->enable_bit - AM35XX_IPSS_ICK_FCK_OFFSET;
  84}
  85
  86const struct clkops clkops_am35xx_ipss_module_wait = {
  87        .enable         = omap2_dflt_clk_enable,
  88        .disable        = omap2_dflt_clk_disable,
  89        .find_idlest    = am35xx_clk_find_idlest,
  90        .find_companion = am35xx_clk_find_companion,
  91};
  92
  93/**
  94 * am35xx_clk_ipss_find_idlest - return CM_IDLEST info for IPSS
  95 * @clk: struct clk * being enabled
  96 * @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
  97 * @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
  98 * @idlest_val: pointer to a u8 to store the CM_IDLEST indicator
  99 *
 100 * The IPSS target CM_IDLEST bit is at a different shift from the
 101 * CM_{I,F}CLKEN bit.  Pass back the correct info via @idlest_reg
 102 * and @idlest_bit.  No return value.
 103 */
 104static void am35xx_clk_ipss_find_idlest(struct clk *clk,
 105                                            void __iomem **idlest_reg,
 106                                            u8 *idlest_bit,
 107                                            u8 *idlest_val)
 108{
 109        u32 r;
 110
 111        r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
 112        *idlest_reg = (__force void __iomem *)r;
 113        *idlest_bit = AM35XX_ST_IPSS_SHIFT;
 114        *idlest_val = OMAP34XX_CM_IDLEST_VAL;
 115}
 116
 117const struct clkops clkops_am35xx_ipss_wait = {
 118        .enable         = omap2_dflt_clk_enable,
 119        .disable        = omap2_dflt_clk_disable,
 120        .find_idlest    = am35xx_clk_ipss_find_idlest,
 121        .find_companion = omap2_clk_dflt_find_companion,
 122        .allow_idle     = omap2_clkt_iclk_allow_idle,
 123        .deny_idle      = omap2_clkt_iclk_deny_idle,
 124};
 125
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