diff options
Diffstat (limited to 'arch/arm/mach-mx3/mxc_pm.c')
| -rw-r--r-- | arch/arm/mach-mx3/mxc_pm.c | 440 |
1 files changed, 440 insertions, 0 deletions
diff --git a/arch/arm/mach-mx3/mxc_pm.c b/arch/arm/mach-mx3/mxc_pm.c new file mode 100644 index 000000000000..97bfba956922 --- /dev/null +++ b/arch/arm/mach-mx3/mxc_pm.c @@ -0,0 +1,440 @@ +/* + * Copyright 2005-2009 Freescale Semiconductor, Inc. All Rights Reserved. + */ + +/* + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +/*! + * @defgroup DPM_MX31 Power Management + * @ingroup MSL_MX31 + */ +/*! + * @file mach-mx3/mxc_pm.c + * + * @brief This file provides all the kernel level and user level API + * definitions for the CRM_MCU and DPLL in mx3. + * + * @ingroup DPM_MX31 + */ + +/* + * Include Files + */ +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/clk.h> +#include <mach/hardware.h> +#include <mach/system.h> +#include <mach/mxc_pm.h> +#include <asm/cacheflush.h> +#include <asm/irq.h> +#include <mach/common.h> +#include <asm/hardware/cache-l2x0.h> + +#include "crm_regs.h" + +/* Local defines */ +#define FREQ_COMP_TOLERANCE 200 /* tolerance percentage times 100 */ +#define MCU_PLL_MAX_FREQ 600000000 /* Maximum frequency MCU PLL clock */ +#define MCU_PLL_MIN_FREQ 160000000 /* Minimum frequency MCU PLL clock */ +#define NFC_MAX_FREQ 20000000 /* Maximum frequency NFC clock */ +#define PRE_DIV_MIN_FREQ 10000000 /* Minimum Frequency after Predivider */ + +static struct clk *mcu_pll_clk; +static struct clk *cpu_clk; +static struct clk *ahb_clk; +static struct clk *ipg_clk; + +/*! + * Spinlock to protect CRM register accesses + */ +static DEFINE_SPINLOCK(mxc_crm_lock); + +/*! + * This function is called to modify the contents of a CCM_MCU register + * + * @param reg_offset the CCM_MCU register that will read + * @param mask the mask to be used to clear the bits that are to be modified + * @param data the data that should be written to the register + */ +void mxc_ccm_modify_reg(void *reg_offset, unsigned int mask, + unsigned int data) +{ + unsigned long flags; + unsigned long reg; + + spin_lock_irqsave(&mxc_crm_lock, flags); + reg = __raw_readl(reg_offset); + reg = (reg & (~mask)) | data; + __raw_writel(reg, reg_offset); + spin_unlock_irqrestore(&mxc_crm_lock, flags); +} + +/*! + * Compare two frequences using allowable tolerance + * + * The MX3 PLL can generate many frequencies. This function + * compares the generated frequency to the requested frequency + * and determines it they are within and acceptable tolerance. + * + * @param freq1 desired frequency + * @param freq2 generated frequency + * + * @return Returns 0 is frequencies are within talerance + * and non-zero is they are not. + */ +static int freq_equal(unsigned long freq1, unsigned long freq2) +{ + if (freq1 > freq2) { + return (freq1 - freq2) <= (freq1 / FREQ_COMP_TOLERANCE); + } + return (freq2 - freq1) <= (freq1 / FREQ_COMP_TOLERANCE); +} + +/*! + * Calculate new MCU clock dividers for the PDR0 regiser. + * + * @param mcu_main_clk PLL output frequency (Hz) + * @param arm_freq desired ARM frequency (Hz) + * @param max_freq desired MAX frequency (Hz) + * @param ip_freq desired IP frequency (Hz) + * @param mask were to return PDR0 mask + * @param value were to return PDR0 value + * + * @return Returns 0 on success or + * Returns non zero if error + * PLL_LESS_ARM_ERR if pll frequency is less than + * desired core frequency + * FREQ_OUT_OF_RANGE if desided frequencies ar not + * possible with the current mcu pll frequency. + */ +static int +cal_pdr0_value(unsigned long mcu_main_clk, + long arm_freq, + long max_freq, + long ip_freq, unsigned long *mask, unsigned long *value) +{ + unsigned long arm_div; /* ARM core clock divider */ + unsigned long max_div; /* MAX clock divider */ + unsigned long ipg_div; /* IPG clock divider */ + unsigned long nfc_div; /* NFC (Nand Flash Controller) clock divider */ + unsigned long hsp_div; /* HSP clock divider */ + + if (arm_freq > mcu_main_clk) { + return -PLL_LESS_ARM_ERR; + } + + arm_div = mcu_main_clk / arm_freq; + if ((arm_div == 0) || !freq_equal(arm_freq, mcu_main_clk / arm_div)) { + return FREQ_OUT_OF_RANGE; + } + max_div = mcu_main_clk / max_freq; + if ((max_div == 0) || !freq_equal(max_freq, mcu_main_clk / max_div)) { + return FREQ_OUT_OF_RANGE; + } + hsp_div = max_div; + + ipg_div = max_freq / ip_freq; + if ((ipg_div == 0) || !freq_equal(ip_freq, max_freq / ipg_div)) { + return FREQ_OUT_OF_RANGE; + } + + nfc_div = ((max_freq - 1000000) / NFC_MAX_FREQ) + 1; + + /* All of the divider values have been calculated. + * Now change the hardware register. */ + + *mask = MXC_CCM_PDR0_HSP_PODF_MASK | + MXC_CCM_PDR0_NFC_PODF_MASK | + MXC_CCM_PDR0_IPG_PODF_MASK | + MXC_CCM_PDR0_MAX_PODF_MASK | MXC_CCM_PDR0_MCU_PODF_MASK; + + *value = ((hsp_div - 1) << MXC_CCM_PDR0_HSP_PODF_OFFSET) | + ((nfc_div - 1) << MXC_CCM_PDR0_NFC_PODF_OFFSET) | + ((ipg_div - 1) << MXC_CCM_PDR0_IPG_PODF_OFFSET) | + ((max_div - 1) << MXC_CCM_PDR0_MAX_PODF_OFFSET) | + ((arm_div - 1) << MXC_CCM_PDR0_MCU_PODF_OFFSET); + + return 0; +} + +/*! + * Integer clock scaling + * + * Change main arm clock frequencies without changing the PLL. + * The integer dividers are changed to produce the desired + * frequencies. The number of valid frequency are limited and + * are determined by the current MCU PLL frequency + * + * @param arm_freq desired ARM frequency (Hz) + * @param max_freq desired MAX frequency (Hz) + * @param ip_freq desired IP frequency (Hz) + * + * @return Returns 0 on success or + * Returns non zero if error + * PLL_LESS_ARM_ERR if pll frequency is less than + * desired core frequency + * FREQ_OUT_OF_RANGE if desided frequencies ar not + * possible with the current mcu pll frequency. + */ +int mxc_pm_intscale(long arm_freq, long max_freq, long ip_freq) +{ + unsigned long mcu_main_clk; /* mcu clock domain main clock */ + unsigned long mask; + unsigned long value; + int ret_value; + + printk(KERN_INFO "arm_freq=%ld, max_freq=%ld, ip_freq=%ld\n", + arm_freq, max_freq, ip_freq); + //print_frequencies(); /* debug */ + + mcu_main_clk = clk_get_rate(mcu_pll_clk); + ret_value = cal_pdr0_value(mcu_main_clk, arm_freq, max_freq, ip_freq, + &mask, &value); + if ((arm_freq != clk_round_rate(cpu_clk, arm_freq)) || + (max_freq != clk_round_rate(ahb_clk, max_freq)) || + (ip_freq != clk_round_rate(ipg_clk, ip_freq))) { + return -EINVAL; + } + + if ((max_freq != clk_get_rate(ahb_clk)) || + (ip_freq != clk_get_rate(ipg_clk))) { + return -EINVAL; + } + + if (arm_freq != clk_get_rate(cpu_clk)) { + ret_value = clk_set_rate(cpu_clk, arm_freq); + } + return ret_value; +} + +/*! + * PLL clock scaling + * + * Change MCU PLL frequency and adjust derived clocks. Integer + * dividers are used generate the derived clocks so changed to produce + * the desired the valid frequencies are limited by the desired ARM + * frequency. + * + * The clock source for the MCU is set to the MCU PLL. + * + * @param arm_freq desired ARM frequency (Hz) + * @param max_freq desired MAX frequency (Hz) + * @param ip_freq desired IP frequency (Hz) + * + * @return Returns 0 on success or + * Returns non zero if error + * PLL_LESS_ARM_ERR if pll frequency is less than + * desired core frequency + * FREQ_OUT_OF_RANGE if desided frequencies ar not + * possible with the current mcu pll frequency. + */ +int mxc_pm_pllscale(long arm_freq, long max_freq, long ip_freq) +{ + signed long pll_freq = 0; /* target pll frequency */ + unsigned long old_pll; + unsigned long mask; + unsigned long value; + int ret_value; + + printk(KERN_INFO "arm_freq=%ld, max_freq=%ld, ip_freq=%ld\n", + arm_freq, max_freq, ip_freq); + //print_frequencies(); + + do { + pll_freq += arm_freq; + if ((pll_freq > MCU_PLL_MAX_FREQ) || (pll_freq / 8 > arm_freq)) { + return FREQ_OUT_OF_RANGE; + } + if (pll_freq < MCU_PLL_MIN_FREQ) { + ret_value = 111; + } else { + ret_value = + cal_pdr0_value(pll_freq, arm_freq, max_freq, + ip_freq, &mask, &value); + } + } while (ret_value != 0); + + old_pll = clk_get_rate(mcu_pll_clk); + if (pll_freq > old_pll) { + /* if pll freq is increasing then change dividers first */ + mxc_ccm_modify_reg(MXC_CCM_PDR0, mask, value); + ret_value = clk_set_rate(mcu_pll_clk, pll_freq); + } else { + /* if pll freq is decreasing then change pll first */ + ret_value = clk_set_rate(mcu_pll_clk, pll_freq); + mxc_ccm_modify_reg(MXC_CCM_PDR0, mask, value); + } + //print_frequencies(); + return ret_value; +} + +/*! + * Implementing steps required to transition to low-power modes + * + * @param mode The desired low-power mode. Possible values are, + * WAIT_MODE, DOZE_MODE, STOP_MODE or DSM_MODE + * + */ +void mxc_pm_lowpower(int mode) +{ + unsigned int lpm; + int enable_flag; + unsigned long reg; + + local_irq_disable(); + enable_flag = 0; + + switch (mode) { + case STOP_MODE: + /* State Retention mode */ + lpm = 2; + /* Disable timer interrupt */ + disable_irq(MXC_INT_GPT); + enable_flag = 1; + + /* Enable Well Bias and set VSTBY + * VSTBY pin will be asserted during SR mode. This asks the + * PM IC to set the core voltage to the standby voltage + * Must clear the MXC_CCM_CCMR_SBYCS bit as well */ + mxc_ccm_modify_reg(MXC_CCM_CCMR, + MXC_CCM_CCMR_WBEN | MXC_CCM_CCMR_VSTBY | + MXC_CCM_CCMR_SBYCS, + MXC_CCM_CCMR_WBEN | MXC_CCM_CCMR_VSTBY | + MXC_CCM_CCMR_SBYCS); + + mxc_ccm_modify_reg(MXC_CCM_CCMR, + MXC_CCM_CCMR_LPM_MASK, + lpm << MXC_CCM_CCMR_LPM_OFFSET); + cpu_do_idle(); + break; + + case DSM_MODE: + /* Deep Sleep Mode */ + lpm = 3; + /* Disable timer interrupt */ + disable_irq(MXC_INT_GPT); + enable_flag = 1; + /* Enabled Well Bias + * SBYCS = 0, MCU clock source is disabled*/ + mxc_ccm_modify_reg(MXC_CCM_CCMR, + MXC_CCM_CCMR_WBEN | MXC_CCM_CCMR_VSTBY | + MXC_CCM_CCMR_SBYCS | MXC_CCM_CCMR_LPM_MASK, + MXC_CCM_CCMR_WBEN | MXC_CCM_CCMR_VSTBY | + MXC_CCM_CCMR_SBYCS | + (lpm << MXC_CCM_CCMR_LPM_OFFSET)); + + /* wake up by keypad */ + reg = __raw_readl(MXC_CCM_WIMR); + reg &= ~(1 << 18); + __raw_writel(reg, MXC_CCM_WIMR); + + flush_cache_all(); + l2x0_disable(); + + mxc_pm_arch_entry(IO_ADDRESS(MX31_NFC_BASE_ADDR), 2048); + printk(KERN_INFO "Resume from DSM\n"); + + l2x0_enable(); + mxc_init_irq(); + + break; + default: + case WAIT_MODE: + /* Wait is the default mode used when idle. */ + reg = __raw_readl(MXC_CCM_CCMR); + reg &= ~MXC_CCM_CCMR_LPM_MASK; + __raw_writel(reg, MXC_CCM_CCMR); + break; + } + + if (enable_flag) { + /* Enable timer interrupt */ + enable_irq(MXC_INT_GPT); + } + local_irq_enable(); +} + +#ifdef CONFIG_MXC_DVFS +/*! + * Changes MCU frequencies using dvfs. + * + * @param armfreq desired ARM frequency in Hz + * @param ahbfreq desired AHB frequency in Hz + * @param ipfreq desired IP frequency in Hz + * + * @return Returns 0 on success, non-zero on error + */ +int mxc_pm_dvfs(unsigned long armfreq, long ahbfreq, long ipfreq) +{ + int ret_value; + int i; + + if (ahbfreq != 133000000) { + return FREQ_OUT_OF_RANGE; + } + if (ipfreq != 66500000) { + return FREQ_OUT_OF_RANGE; + } + ret_value = FREQ_OUT_OF_RANGE; + for (i = 0; i < dvfs_states_tbl->num_of_states; i++) { + if (dvfs_states_tbl->freqs[i] == armfreq) { + ret_value = dvfs_set_state(i); + break; + } + } + + return ret_value; +} +#endif /* CONFIG_MXC_DVFS */ + +/*! + * This function is used to load the module. + * + * @return Returns an Integer on success + */ +static int __init mxc_pm_init_module(void) +{ + printk(KERN_INFO "Low-Level PM Driver module loaded\n"); + + mcu_pll_clk = clk_get(NULL, "mcu_pll"); + cpu_clk = clk_get(NULL, "cpu_clk"); + ahb_clk = clk_get(NULL, "ahb_clk"); + ipg_clk = clk_get(NULL, "ipg_clk"); + return 0; +} + +/*! + * This function is used to unload the module + */ +static void __exit mxc_pm_cleanup_module(void) +{ + clk_put(mcu_pll_clk); + clk_put(cpu_clk); + clk_put(ahb_clk); + clk_put(ipg_clk); + printk(KERN_INFO "Low-Level PM Driver module Unloaded\n"); +} + +module_init(mxc_pm_init_module); +module_exit(mxc_pm_cleanup_module); + +EXPORT_SYMBOL(mxc_pm_intscale); +EXPORT_SYMBOL(mxc_pm_pllscale); +EXPORT_SYMBOL(mxc_pm_lowpower); +#ifdef CONFIG_MXC_DVFS +EXPORT_SYMBOL(mxc_pm_dvfs); +#endif + +MODULE_AUTHOR("Freescale Semiconductor, Inc."); +MODULE_DESCRIPTION("MX3 Low-level Power Management Driver"); +MODULE_LICENSE("GPL"); |