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 #include <linux/bug.h> 18 19 #include "cm2xxx.h" 20 #include "cm3xxx.h" 21 #include "cm44xx.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 * omap_cm_wait_module_ready - wait for a module to leave idle or standby 76 * @part: PRCM partition 77 * @prcm_mod: PRCM module offset 78 * @idlest_reg: CM_IDLESTx register 79 * @idlest_shift: shift of the bit in the CM_IDLEST* register to check 80 * 81 * Wait for the PRCM to indicate that the module identified by 82 * (@prcm_mod, @idlest_id, @idlest_shift) is clocked. Return 0 upon 83 * success, -EBUSY if the module doesn't enable in time, or -EINVAL if 84 * no per-SoC wait_module_ready() function pointer has been registered 85 * or if the idlest register is unknown on the SoC. 86 */ 87 int omap_cm_wait_module_ready(u8 part, s16 prcm_mod, u16 idlest_reg, 88 u8 idlest_shift) 89 { 90 if (!cm_ll_data->wait_module_ready) { 91 WARN_ONCE(1, "cm: %s: no low-level function defined\n", 92 __func__); 93 return -EINVAL; 94 } 95 96 return cm_ll_data->wait_module_ready(part, prcm_mod, idlest_reg, 97 idlest_shift); 98 } 99 100 /** 101 * omap_cm_wait_module_idle - wait for a module to enter idle or standby 102 * @part: PRCM partition 103 * @prcm_mod: PRCM module offset 104 * @idlest_reg: CM_IDLESTx register 105 * @idlest_shift: shift of the bit in the CM_IDLEST* register to check 106 * 107 * Wait for the PRCM to indicate that the module identified by 108 * (@prcm_mod, @idlest_id, @idlest_shift) is no longer clocked. Return 109 * 0 upon success, -EBUSY if the module doesn't enable in time, or 110 * -EINVAL if no per-SoC wait_module_idle() function pointer has been 111 * registered or if the idlest register is unknown on the SoC. 112 */ 113 int omap_cm_wait_module_idle(u8 part, s16 prcm_mod, u16 idlest_reg, 114 u8 idlest_shift) 115 { 116 if (!cm_ll_data->wait_module_idle) { 117 WARN_ONCE(1, "cm: %s: no low-level function defined\n", 118 __func__); 119 return -EINVAL; 120 } 121 122 return cm_ll_data->wait_module_idle(part, prcm_mod, idlest_reg, 123 idlest_shift); 124 } 125 126 /** 127 * omap_cm_module_enable - enable a module 128 * @mode: target mode for the module 129 * @part: PRCM partition 130 * @inst: PRCM instance 131 * @clkctrl_offs: CM_CLKCTRL register offset for the module 132 * 133 * Enables clocks for a module identified by (@part, @inst, @clkctrl_offs) 134 * making its IO space accessible. Return 0 upon success, -EINVAL if no 135 * per-SoC module_enable() function pointer has been registered. 136 */ 137 int omap_cm_module_enable(u8 mode, u8 part, u16 inst, u16 clkctrl_offs) 138 { 139 if (!cm_ll_data->module_enable) { 140 WARN_ONCE(1, "cm: %s: no low-level function defined\n", 141 __func__); 142 return -EINVAL; 143 } 144 145 cm_ll_data->module_enable(mode, part, inst, clkctrl_offs); 146 return 0; 147 } 148 149 /** 150 * omap_cm_module_disable - disable a module 151 * @part: PRCM partition 152 * @inst: PRCM instance 153 * @clkctrl_offs: CM_CLKCTRL register offset for the module 154 * 155 * Disables clocks for a module identified by (@part, @inst, @clkctrl_offs) 156 * makings its IO space inaccessible. Return 0 upon success, -EINVAL if 157 * no per-SoC module_disable() function pointer has been registered. 158 */ 159 int omap_cm_module_disable(u8 part, u16 inst, u16 clkctrl_offs) 160 { 161 if (!cm_ll_data->module_disable) { 162 WARN_ONCE(1, "cm: %s: no low-level function defined\n", 163 __func__); 164 return -EINVAL; 165 } 166 167 cm_ll_data->module_disable(part, inst, clkctrl_offs); 168 return 0; 169 } 170 171 /** 172 * cm_register - register per-SoC low-level data with the CM 173 * @cld: low-level per-SoC OMAP CM data & function pointers to register 174 * 175 * Register per-SoC low-level OMAP CM data and function pointers with 176 * the OMAP CM common interface. The caller must keep the data 177 * pointed to by @cld valid until it calls cm_unregister() and 178 * it returns successfully. Returns 0 upon success, -EINVAL if @cld 179 * is NULL, or -EEXIST if cm_register() has already been called 180 * without an intervening cm_unregister(). 181 */ 182 int cm_register(struct cm_ll_data *cld) 183 { 184 if (!cld) 185 return -EINVAL; 186 187 if (cm_ll_data != &null_cm_ll_data) 188 return -EEXIST; 189 190 cm_ll_data = cld; 191 192 return 0; 193 } 194 195 /** 196 * cm_unregister - unregister per-SoC low-level data & function pointers 197 * @cld: low-level per-SoC OMAP CM data & function pointers to unregister 198 * 199 * Unregister per-SoC low-level OMAP CM data and function pointers 200 * that were previously registered with cm_register(). The 201 * caller may not destroy any of the data pointed to by @cld until 202 * this function returns successfully. Returns 0 upon success, or 203 * -EINVAL if @cld is NULL or if @cld does not match the struct 204 * cm_ll_data * previously registered by cm_register(). 205 */ 206 int cm_unregister(struct cm_ll_data *cld) 207 { 208 if (!cld || cm_ll_data != cld) 209 return -EINVAL; 210 211 cm_ll_data = &null_cm_ll_data; 212 213 return 0; 214 } 215