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 */ 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 */ 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 */ 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 */ 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 */ 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