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