xref: /openbmc/linux/drivers/clk/ti/clkt_iclk.c (revision e2c75e76)
1 /*
2  * OMAP2/3 interface clock control
3  *
4  * Copyright (C) 2011 Nokia Corporation
5  * Paul Walmsley
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #undef DEBUG
12 
13 #include <linux/kernel.h>
14 #include <linux/clk-provider.h>
15 #include <linux/io.h>
16 #include <linux/clk/ti.h>
17 
18 #include "clock.h"
19 
20 /* Register offsets */
21 #define OMAP24XX_CM_FCLKEN2		0x04
22 #define CM_AUTOIDLE			0x30
23 #define CM_ICLKEN			0x10
24 #define CM_IDLEST			0x20
25 
26 #define OMAP24XX_CM_IDLEST_VAL		0
27 
28 /* Private functions */
29 
30 /* XXX */
31 void omap2_clkt_iclk_allow_idle(struct clk_hw_omap *clk)
32 {
33 	u32 v;
34 	struct clk_omap_reg r;
35 
36 	memcpy(&r, &clk->enable_reg, sizeof(r));
37 	r.offset ^= (CM_AUTOIDLE ^ CM_ICLKEN);
38 
39 	v = ti_clk_ll_ops->clk_readl(&r);
40 	v |= (1 << clk->enable_bit);
41 	ti_clk_ll_ops->clk_writel(v, &r);
42 }
43 
44 /* XXX */
45 void omap2_clkt_iclk_deny_idle(struct clk_hw_omap *clk)
46 {
47 	u32 v;
48 	struct clk_omap_reg r;
49 
50 	memcpy(&r, &clk->enable_reg, sizeof(r));
51 
52 	r.offset ^= (CM_AUTOIDLE ^ CM_ICLKEN);
53 
54 	v = ti_clk_ll_ops->clk_readl(&r);
55 	v &= ~(1 << clk->enable_bit);
56 	ti_clk_ll_ops->clk_writel(v, &r);
57 }
58 
59 /**
60  * omap2430_clk_i2chs_find_idlest - return CM_IDLEST info for 2430 I2CHS
61  * @clk: struct clk * being enabled
62  * @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
63  * @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
64  * @idlest_val: pointer to a u8 to store the CM_IDLEST indicator
65  *
66  * OMAP2430 I2CHS CM_IDLEST bits are in CM_IDLEST1_CORE, but the
67  * CM_*CLKEN bits are in CM_{I,F}CLKEN2_CORE.  This custom function
68  * passes back the correct CM_IDLEST register address for I2CHS
69  * modules.  No return value.
70  */
71 static void omap2430_clk_i2chs_find_idlest(struct clk_hw_omap *clk,
72 					   struct clk_omap_reg *idlest_reg,
73 					   u8 *idlest_bit,
74 					   u8 *idlest_val)
75 {
76 	memcpy(idlest_reg, &clk->enable_reg, sizeof(*idlest_reg));
77 	idlest_reg->offset ^= (OMAP24XX_CM_FCLKEN2 ^ CM_IDLEST);
78 	*idlest_bit = clk->enable_bit;
79 	*idlest_val = OMAP24XX_CM_IDLEST_VAL;
80 }
81 
82 /* Public data */
83 
84 const struct clk_hw_omap_ops clkhwops_iclk = {
85 	.allow_idle	= omap2_clkt_iclk_allow_idle,
86 	.deny_idle	= omap2_clkt_iclk_deny_idle,
87 };
88 
89 const struct clk_hw_omap_ops clkhwops_iclk_wait = {
90 	.allow_idle	= omap2_clkt_iclk_allow_idle,
91 	.deny_idle	= omap2_clkt_iclk_deny_idle,
92 	.find_idlest	= omap2_clk_dflt_find_idlest,
93 	.find_companion	= omap2_clk_dflt_find_companion,
94 };
95 
96 /* 2430 I2CHS has non-standard IDLEST register */
97 const struct clk_hw_omap_ops clkhwops_omap2430_i2chs_wait = {
98 	.find_idlest	= omap2430_clk_i2chs_find_idlest,
99 	.find_companion	= omap2_clk_dflt_find_companion,
100 };
101