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};