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 "clock.h"
  25#include "clock3517.h"
  26#include "cm3xxx.h"
  27#include "cm-regbits-34xx.h"
  28
  29/*
  30 * In AM35xx IPSS, the {ICK,FCK} enable bits for modules are exported
  31 * in the same register at a bit offset of 0x8. The EN_ACK for ICK is
  32 * at an offset of 4 from ICK enable bit.
  33 */
  34#define AM35XX_IPSS_ICK_MASK                    0xF
  35#define AM35XX_IPSS_ICK_EN_ACK_OFFSET           0x4
  36#define AM35XX_IPSS_ICK_FCK_OFFSET              0x8
  37#define AM35XX_IPSS_CLK_IDLEST_VAL              0
  38
  39/**
  40 * am35xx_clk_find_idlest - return clock ACK info for AM35XX IPSS
  41 * @clk: struct clk * being enabled
  42 * @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
  43 * @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
  44 * @idlest_val: pointer to a u8 to store the CM_IDLEST indicator
  45 *
  46 * The interface clocks on AM35xx IPSS reflects the clock idle status
  47 * in the enable register itsel at a bit offset of 4 from the enable
  48 * bit. A value of 1 indicates that clock is enabled.
  49 */
  50static void am35xx_clk_find_idlest(struct clk_hw_omap *clk,
  51                                            void __iomem **idlest_reg,
  52                                            u8 *idlest_bit,
  53                                            u8 *idlest_val)
  54{
  55        *idlest_reg = (__force void __iomem *)(clk->enable_reg);
  56        *idlest_bit = clk->enable_bit + AM35XX_IPSS_ICK_EN_ACK_OFFSET;
  57        *idlest_val = AM35XX_IPSS_CLK_IDLEST_VAL;
  58}
  59
  60/**
  61 * am35xx_clk_find_companion - find companion clock to @clk
  62 * @clk: struct clk * to find the companion clock of
  63 * @other_reg: void __iomem ** to return the companion clock CM_*CLKEN va in
  64 * @other_bit: u8 ** to return the companion clock bit shift in
  65 *
  66 * Some clocks don't have companion clocks.  For example, modules with
  67 * only an interface clock (such as HECC) don't have a companion
  68 * clock.  Right now, this code relies on the hardware exporting a bit
  69 * in the correct companion register that indicates that the
  70 * nonexistent 'companion clock' is active.  Future patches will
  71 * associate this type of code with per-module data structures to
  72 * avoid this issue, and remove the casts.  No return value.
  73 */
  74static void am35xx_clk_find_companion(struct clk_hw_omap *clk,
  75                                      void __iomem **other_reg,
  76                                      u8 *other_bit)
  77{
  78        *other_reg = (__force void __iomem *)(clk->enable_reg);
  79        if (clk->enable_bit & AM35XX_IPSS_ICK_MASK)
  80                *other_bit = clk->enable_bit + AM35XX_IPSS_ICK_FCK_OFFSET;
  81        else
  82                *other_bit = clk->enable_bit - AM35XX_IPSS_ICK_FCK_OFFSET;
  83}
  84const struct clk_hw_omap_ops clkhwops_am35xx_ipss_module_wait = {
  85        .find_idlest    = am35xx_clk_find_idlest,
  86        .find_companion = am35xx_clk_find_companion,
  87};
  88
  89/**
  90 * am35xx_clk_ipss_find_idlest - return CM_IDLEST info for IPSS
  91 * @clk: struct clk * being enabled
  92 * @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
  93 * @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
  94 * @idlest_val: pointer to a u8 to store the CM_IDLEST indicator
  95 *
  96 * The IPSS target CM_IDLEST bit is at a different shift from the
  97 * CM_{I,F}CLKEN bit.  Pass back the correct info via @idlest_reg
  98 * and @idlest_bit.  No return value.
  99 */
 100static void am35xx_clk_ipss_find_idlest(struct clk_hw_omap *clk,
 101                                            void __iomem **idlest_reg,
 102                                            u8 *idlest_bit,
 103                                            u8 *idlest_val)
 104{
 105        u32 r;
 106
 107        r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
 108        *idlest_reg = (__force void __iomem *)r;
 109        *idlest_bit = AM35XX_ST_IPSS_SHIFT;
 110        *idlest_val = OMAP34XX_CM_IDLEST_VAL;
 111}
 112
 113const struct clk_hw_omap_ops clkhwops_am35xx_ipss_wait = {
 114        .allow_idle     = omap2_clkt_iclk_allow_idle,
 115        .deny_idle      = omap2_clkt_iclk_deny_idle,
 116        .find_idlest    = am35xx_clk_ipss_find_idlest,
 117        .find_companion = omap2_clk_dflt_find_companion,
 118};
 119