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 */
am35xx_clk_find_idlest(struct clk * clk,void __iomem ** idlest_reg,u8 * idlest_bit,u8 * idlest_val)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 */
am35xx_clk_find_companion(struct clk * clk,void __iomem ** other_reg,u8 * other_bit)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 */
am35xx_clk_ipss_find_idlest(struct clk * clk,void __iomem ** idlest_reg,u8 * idlest_bit,u8 * idlest_val)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
127