1 /*
2 * OMAP2+ common Clock Management (CM) IP block functions
3 *
4 * Copyright (C) 2012 Texas Instruments, Inc.
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 * XXX This code should eventually be moved to a CM driver.
12 */
13
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/errno.h>
17
18 #include "cm2xxx.h"
19 #include "cm3xxx.h"
20 #include "cm44xx.h"
21 #include "common.h"
22
23 /*
24 * cm_ll_data: function pointers to SoC-specific implementations of
25 * common CM functions
26 */
27 static struct cm_ll_data null_cm_ll_data;
28 static struct cm_ll_data *cm_ll_data = &null_cm_ll_data;
29
30 /* cm_base: base virtual address of the CM IP block */
31 void __iomem *cm_base;
32
33 /* cm2_base: base virtual address of the CM2 IP block (OMAP44xx only) */
34 void __iomem *cm2_base;
35
36 /**
37 * omap2_set_globals_cm - set the CM/CM2 base addresses (for early use)
38 * @cm: CM base virtual address
39 * @cm2: CM2 base virtual address (if present on the booted SoC)
40 *
41 * XXX Will be replaced when the PRM/CM drivers are completed.
42 */
omap2_set_globals_cm(void __iomem * cm,void __iomem * cm2)43 void __init omap2_set_globals_cm(void __iomem *cm, void __iomem *cm2)
44 {
45 cm_base = cm;
46 cm2_base = cm2;
47 }
48
49 /**
50 * cm_split_idlest_reg - split CM_IDLEST reg addr into its components
51 * @idlest_reg: CM_IDLEST* virtual address
52 * @prcm_inst: pointer to an s16 to return the PRCM instance offset
53 * @idlest_reg_id: pointer to a u8 to return the CM_IDLESTx register ID
54 *
55 * Given an absolute CM_IDLEST register address @idlest_reg, passes
56 * the PRCM instance offset and IDLEST register ID back to the caller
57 * via the @prcm_inst and @idlest_reg_id. Returns -EINVAL upon error,
58 * or 0 upon success. XXX This function is only needed until absolute
59 * register addresses are removed from the OMAP struct clk records.
60 */
cm_split_idlest_reg(void __iomem * idlest_reg,s16 * prcm_inst,u8 * idlest_reg_id)61 int cm_split_idlest_reg(void __iomem *idlest_reg, s16 *prcm_inst,
62 u8 *idlest_reg_id)
63 {
64 if (!cm_ll_data->split_idlest_reg) {
65 WARN_ONCE(1, "cm: %s: no low-level function defined\n",
66 __func__);
67 return -EINVAL;
68 }
69
70 return cm_ll_data->split_idlest_reg(idlest_reg, prcm_inst,
71 idlest_reg_id);
72 }
73
74 /**
75 * cm_wait_module_ready - wait for a module to leave idle or standby
76 * @prcm_mod: PRCM module offset
77 * @idlest_id: CM_IDLESTx register ID (i.e., x = 1, 2, 3)
78 * @idlest_shift: shift of the bit in the CM_IDLEST* register to check
79 *
80 * Wait for the PRCM to indicate that the module identified by
81 * (@prcm_mod, @idlest_id, @idlest_shift) is clocked. Return 0 upon
82 * success, -EBUSY if the module doesn't enable in time, or -EINVAL if
83 * no per-SoC wait_module_ready() function pointer has been registered
84 * or if the idlest register is unknown on the SoC.
85 */
cm_wait_module_ready(s16 prcm_mod,u8 idlest_id,u8 idlest_shift)86 int cm_wait_module_ready(s16 prcm_mod, u8 idlest_id, u8 idlest_shift)
87 {
88 if (!cm_ll_data->wait_module_ready) {
89 WARN_ONCE(1, "cm: %s: no low-level function defined\n",
90 __func__);
91 return -EINVAL;
92 }
93
94 return cm_ll_data->wait_module_ready(prcm_mod, idlest_id, idlest_shift);
95 }
96
97 /**
98 * cm_register - register per-SoC low-level data with the CM
99 * @cld: low-level per-SoC OMAP CM data & function pointers to register
100 *
101 * Register per-SoC low-level OMAP CM data and function pointers with
102 * the OMAP CM common interface. The caller must keep the data
103 * pointed to by @cld valid until it calls cm_unregister() and
104 * it returns successfully. Returns 0 upon success, -EINVAL if @cld
105 * is NULL, or -EEXIST if cm_register() has already been called
106 * without an intervening cm_unregister().
107 */
cm_register(struct cm_ll_data * cld)108 int cm_register(struct cm_ll_data *cld)
109 {
110 if (!cld)
111 return -EINVAL;
112
113 if (cm_ll_data != &null_cm_ll_data)
114 return -EEXIST;
115
116 cm_ll_data = cld;
117
118 return 0;
119 }
120
121 /**
122 * cm_unregister - unregister per-SoC low-level data & function pointers
123 * @cld: low-level per-SoC OMAP CM data & function pointers to unregister
124 *
125 * Unregister per-SoC low-level OMAP CM data and function pointers
126 * that were previously registered with cm_register(). The
127 * caller may not destroy any of the data pointed to by @cld until
128 * this function returns successfully. Returns 0 upon success, or
129 * -EINVAL if @cld is NULL or if @cld does not match the struct
130 * cm_ll_data * previously registered by cm_register().
131 */
cm_unregister(struct cm_ll_data * cld)132 int cm_unregister(struct cm_ll_data *cld)
133 {
134 if (!cld || cm_ll_data != cld)
135 return -EINVAL;
136
137 cm_ll_data = &null_cm_ll_data;
138
139 return 0;
140 }
141