diff options
Diffstat (limited to 'kernel/arch/arm/mach-omap2/cm33xx.c')
| -rw-r--r-- | kernel/arch/arm/mach-omap2/cm33xx.c | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-omap2/cm33xx.c b/kernel/arch/arm/mach-omap2/cm33xx.c new file mode 100644 index 000000000..7b181f929 --- /dev/null +++ b/kernel/arch/arm/mach-omap2/cm33xx.c @@ -0,0 +1,364 @@ +/* + * AM33XX CM functions + * + * Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/ + * Vaibhav Hiremath <hvaibhav@ti.com> + * + * Reference taken from from OMAP4 cminst44xx.c + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/io.h> + +#include "clockdomain.h" +#include "cm.h" +#include "cm33xx.h" +#include "cm-regbits-34xx.h" +#include "cm-regbits-33xx.h" +#include "prm33xx.h" + +/* + * CLKCTRL_IDLEST_*: possible values for the CM_*_CLKCTRL.IDLEST bitfield: + * + * 0x0 func: Module is fully functional, including OCP + * 0x1 trans: Module is performing transition: wakeup, or sleep, or sleep + * abortion + * 0x2 idle: Module is in Idle mode (only OCP part). It is functional if + * using separate functional clock + * 0x3 disabled: Module is disabled and cannot be accessed + * + */ +#define CLKCTRL_IDLEST_FUNCTIONAL 0x0 +#define CLKCTRL_IDLEST_INTRANSITION 0x1 +#define CLKCTRL_IDLEST_INTERFACE_IDLE 0x2 +#define CLKCTRL_IDLEST_DISABLED 0x3 + +/* Private functions */ + +/* Read a register in a CM instance */ +static inline u32 am33xx_cm_read_reg(u16 inst, u16 idx) +{ + return readl_relaxed(cm_base + inst + idx); +} + +/* Write into a register in a CM */ +static inline void am33xx_cm_write_reg(u32 val, u16 inst, u16 idx) +{ + writel_relaxed(val, cm_base + inst + idx); +} + +/* Read-modify-write a register in CM */ +static inline u32 am33xx_cm_rmw_reg_bits(u32 mask, u32 bits, s16 inst, s16 idx) +{ + u32 v; + + v = am33xx_cm_read_reg(inst, idx); + v &= ~mask; + v |= bits; + am33xx_cm_write_reg(v, inst, idx); + + return v; +} + +/** + * _clkctrl_idlest - read a CM_*_CLKCTRL register; mask & shift IDLEST bitfield + * @inst: CM instance register offset (*_INST macro) + * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro) + * + * Return the IDLEST bitfield of a CM_*_CLKCTRL register, shifted down to + * bit 0. + */ +static u32 _clkctrl_idlest(u16 inst, u16 clkctrl_offs) +{ + u32 v = am33xx_cm_read_reg(inst, clkctrl_offs); + v &= AM33XX_IDLEST_MASK; + v >>= AM33XX_IDLEST_SHIFT; + return v; +} + +/** + * _is_module_ready - can module registers be accessed without causing an abort? + * @inst: CM instance register offset (*_INST macro) + * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro) + * + * Returns true if the module's CM_*_CLKCTRL.IDLEST bitfield is either + * *FUNCTIONAL or *INTERFACE_IDLE; false otherwise. + */ +static bool _is_module_ready(u16 inst, u16 clkctrl_offs) +{ + u32 v; + + v = _clkctrl_idlest(inst, clkctrl_offs); + + return (v == CLKCTRL_IDLEST_FUNCTIONAL || + v == CLKCTRL_IDLEST_INTERFACE_IDLE) ? true : false; +} + +/** + * _clktrctrl_write - write @c to a CM_CLKSTCTRL.CLKTRCTRL register bitfield + * @c: CLKTRCTRL register bitfield (LSB = bit 0, i.e., unshifted) + * @inst: CM instance register offset (*_INST macro) + * @cdoffs: Clockdomain register offset (*_CDOFFS macro) + * + * @c must be the unshifted value for CLKTRCTRL - i.e., this function + * will handle the shift itself. + */ +static void _clktrctrl_write(u8 c, u16 inst, u16 cdoffs) +{ + u32 v; + + v = am33xx_cm_read_reg(inst, cdoffs); + v &= ~AM33XX_CLKTRCTRL_MASK; + v |= c << AM33XX_CLKTRCTRL_SHIFT; + am33xx_cm_write_reg(v, inst, cdoffs); +} + +/* Public functions */ + +/** + * am33xx_cm_is_clkdm_in_hwsup - is a clockdomain in hwsup idle mode? + * @inst: CM instance register offset (*_INST macro) + * @cdoffs: Clockdomain register offset (*_CDOFFS macro) + * + * Returns true if the clockdomain referred to by (@inst, @cdoffs) + * is in hardware-supervised idle mode, or 0 otherwise. + */ +static bool am33xx_cm_is_clkdm_in_hwsup(u16 inst, u16 cdoffs) +{ + u32 v; + + v = am33xx_cm_read_reg(inst, cdoffs); + v &= AM33XX_CLKTRCTRL_MASK; + v >>= AM33XX_CLKTRCTRL_SHIFT; + + return (v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ? true : false; +} + +/** + * am33xx_cm_clkdm_enable_hwsup - put a clockdomain in hwsup-idle mode + * @inst: CM instance register offset (*_INST macro) + * @cdoffs: Clockdomain register offset (*_CDOFFS macro) + * + * Put a clockdomain referred to by (@inst, @cdoffs) into + * hardware-supervised idle mode. No return value. + */ +static void am33xx_cm_clkdm_enable_hwsup(u16 inst, u16 cdoffs) +{ + _clktrctrl_write(OMAP34XX_CLKSTCTRL_ENABLE_AUTO, inst, cdoffs); +} + +/** + * am33xx_cm_clkdm_disable_hwsup - put a clockdomain in swsup-idle mode + * @inst: CM instance register offset (*_INST macro) + * @cdoffs: Clockdomain register offset (*_CDOFFS macro) + * + * Put a clockdomain referred to by (@inst, @cdoffs) into + * software-supervised idle mode, i.e., controlled manually by the + * Linux OMAP clockdomain code. No return value. + */ +static void am33xx_cm_clkdm_disable_hwsup(u16 inst, u16 cdoffs) +{ + _clktrctrl_write(OMAP34XX_CLKSTCTRL_DISABLE_AUTO, inst, cdoffs); +} + +/** + * am33xx_cm_clkdm_force_sleep - try to put a clockdomain into idle + * @inst: CM instance register offset (*_INST macro) + * @cdoffs: Clockdomain register offset (*_CDOFFS macro) + * + * Put a clockdomain referred to by (@inst, @cdoffs) into idle + * No return value. + */ +static void am33xx_cm_clkdm_force_sleep(u16 inst, u16 cdoffs) +{ + _clktrctrl_write(OMAP34XX_CLKSTCTRL_FORCE_SLEEP, inst, cdoffs); +} + +/** + * am33xx_cm_clkdm_force_wakeup - try to take a clockdomain out of idle + * @inst: CM instance register offset (*_INST macro) + * @cdoffs: Clockdomain register offset (*_CDOFFS macro) + * + * Take a clockdomain referred to by (@inst, @cdoffs) out of idle, + * waking it up. No return value. + */ +static void am33xx_cm_clkdm_force_wakeup(u16 inst, u16 cdoffs) +{ + _clktrctrl_write(OMAP34XX_CLKSTCTRL_FORCE_WAKEUP, inst, cdoffs); +} + +/* + * + */ + +/** + * am33xx_cm_wait_module_ready - wait for a module to be in 'func' state + * @part: PRCM partition, ignored for AM33xx + * @inst: CM instance register offset (*_INST macro) + * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro) + * @bit_shift: bit shift for the register, ignored for AM33xx + * + * Wait for the module IDLEST to be functional. If the idle state is in any + * the non functional state (trans, idle or disabled), module and thus the + * sysconfig cannot be accessed and will probably lead to an "imprecise + * external abort" + */ +static int am33xx_cm_wait_module_ready(u8 part, s16 inst, u16 clkctrl_offs, + u8 bit_shift) +{ + int i = 0; + + omap_test_timeout(_is_module_ready(inst, clkctrl_offs), + MAX_MODULE_READY_TIME, i); + + return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY; +} + +/** + * am33xx_cm_wait_module_idle - wait for a module to be in 'disabled' + * state + * @part: CM partition, ignored for AM33xx + * @inst: CM instance register offset (*_INST macro) + * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro) + * @bit_shift: bit shift for the register, ignored for AM33xx + * + * Wait for the module IDLEST to be disabled. Some PRCM transition, + * like reset assertion or parent clock de-activation must wait the + * module to be fully disabled. + */ +static int am33xx_cm_wait_module_idle(u8 part, s16 inst, u16 clkctrl_offs, + u8 bit_shift) +{ + int i = 0; + + if (!clkctrl_offs) + return 0; + + omap_test_timeout((_clkctrl_idlest(inst, clkctrl_offs) == + CLKCTRL_IDLEST_DISABLED), + MAX_MODULE_READY_TIME, i); + + return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY; +} + +/** + * am33xx_cm_module_enable - Enable the modulemode inside CLKCTRL + * @mode: Module mode (SW or HW) + * @part: CM partition, ignored for AM33xx + * @inst: CM instance register offset (*_INST macro) + * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro) + * + * No return value. + */ +static void am33xx_cm_module_enable(u8 mode, u8 part, u16 inst, + u16 clkctrl_offs) +{ + u32 v; + + v = am33xx_cm_read_reg(inst, clkctrl_offs); + v &= ~AM33XX_MODULEMODE_MASK; + v |= mode << AM33XX_MODULEMODE_SHIFT; + am33xx_cm_write_reg(v, inst, clkctrl_offs); +} + +/** + * am33xx_cm_module_disable - Disable the module inside CLKCTRL + * @part: CM partition, ignored for AM33xx + * @inst: CM instance register offset (*_INST macro) + * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro) + * + * No return value. + */ +static void am33xx_cm_module_disable(u8 part, u16 inst, u16 clkctrl_offs) +{ + u32 v; + + v = am33xx_cm_read_reg(inst, clkctrl_offs); + v &= ~AM33XX_MODULEMODE_MASK; + am33xx_cm_write_reg(v, inst, clkctrl_offs); +} + +/* + * Clockdomain low-level functions + */ + +static int am33xx_clkdm_sleep(struct clockdomain *clkdm) +{ + am33xx_cm_clkdm_force_sleep(clkdm->cm_inst, clkdm->clkdm_offs); + return 0; +} + +static int am33xx_clkdm_wakeup(struct clockdomain *clkdm) +{ + am33xx_cm_clkdm_force_wakeup(clkdm->cm_inst, clkdm->clkdm_offs); + return 0; +} + +static void am33xx_clkdm_allow_idle(struct clockdomain *clkdm) +{ + am33xx_cm_clkdm_enable_hwsup(clkdm->cm_inst, clkdm->clkdm_offs); +} + +static void am33xx_clkdm_deny_idle(struct clockdomain *clkdm) +{ + am33xx_cm_clkdm_disable_hwsup(clkdm->cm_inst, clkdm->clkdm_offs); +} + +static int am33xx_clkdm_clk_enable(struct clockdomain *clkdm) +{ + if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP) + return am33xx_clkdm_wakeup(clkdm); + + return 0; +} + +static int am33xx_clkdm_clk_disable(struct clockdomain *clkdm) +{ + bool hwsup = false; + + hwsup = am33xx_cm_is_clkdm_in_hwsup(clkdm->cm_inst, clkdm->clkdm_offs); + + if (!hwsup && (clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) + am33xx_clkdm_sleep(clkdm); + + return 0; +} + +struct clkdm_ops am33xx_clkdm_operations = { + .clkdm_sleep = am33xx_clkdm_sleep, + .clkdm_wakeup = am33xx_clkdm_wakeup, + .clkdm_allow_idle = am33xx_clkdm_allow_idle, + .clkdm_deny_idle = am33xx_clkdm_deny_idle, + .clkdm_clk_enable = am33xx_clkdm_clk_enable, + .clkdm_clk_disable = am33xx_clkdm_clk_disable, +}; + +static struct cm_ll_data am33xx_cm_ll_data = { + .wait_module_ready = &am33xx_cm_wait_module_ready, + .wait_module_idle = &am33xx_cm_wait_module_idle, + .module_enable = &am33xx_cm_module_enable, + .module_disable = &am33xx_cm_module_disable, +}; + +int __init am33xx_cm_init(const struct omap_prcm_init_data *data) +{ + return cm_register(&am33xx_cm_ll_data); +} + +static void __exit am33xx_cm_exit(void) +{ + cm_unregister(&am33xx_cm_ll_data); +} +__exitcall(am33xx_cm_exit); |