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  */
  52 static 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  */
  76 static 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
  86 const 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  */
 104 static 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
 117 const 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
 126