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Paul Walmsley657ebfa2010-02-22 22:09:20 -07001/*
2 * OMAP3517/3505-specific clock framework functions
3 *
4 * Copyright (C) 2010 Texas Instruments, Inc.
Paul Walmsleyec538e32011-02-25 15:39:30 -07005 * Copyright (C) 2011 Nokia Corporation
Paul Walmsley657ebfa2010-02-22 22:09:20 -07006 *
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
Paul Walmsley657ebfa2010-02-22 22:09:20 -070024#include "clock.h"
25#include "clock3517.h"
Paul Walmsleyff4ae5d2012-10-21 01:01:11 -060026#include "cm3xxx.h"
Paul Walmsley657ebfa2010-02-22 22:09:20 -070027#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 */
Rajendra Nayakb4777a22012-04-27 15:53:48 +053050static void am35xx_clk_find_idlest(struct clk_hw_omap *clk,
Paul Walmsley657ebfa2010-02-22 22:09:20 -070051 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 */
Rajendra Nayakb4777a22012-04-27 15:53:48 +053074static void am35xx_clk_find_companion(struct clk_hw_omap *clk,
75 void __iomem **other_reg,
Rajendra Nayakb4777a22012-04-27 15:53:48 +053076 u8 *other_bit)
Paul Walmsley657ebfa2010-02-22 22:09:20 -070077{
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}
Rajendra Nayakb4777a22012-04-27 15:53:48 +053084const 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};
Paul Walmsley657ebfa2010-02-22 22:09:20 -070088
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 */
Rajendra Nayakb4777a22012-04-27 15:53:48 +0530100static void am35xx_clk_ipss_find_idlest(struct clk_hw_omap *clk,
Paul Walmsley657ebfa2010-02-22 22:09:20 -0700101 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}
Rajendra Nayak25f42142012-04-27 16:35:52 +0530112
Rajendra Nayakb4777a22012-04-27 15:53:48 +0530113const 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};