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linux/arch/arm/mach-omap2/pm24xx.c
Kevin Hilman 4af4016c53 OMAP3: PM: UART: disable clocks when idle and off-mode support 
This patch allows the UART clocks to be disabled when the OMAP UARTs
are inactive, thus permitting the chip to hit retention in idle.
After the expiration of an activity timer, each UART is allowed to
disable its clocks so the system can enter retention.  The activity
timer is (re)activated on any UART interrupt, UART wake event or any
IO pad wakeup.  The actual disable of the UART clocks is done in the
'prepare_idle' hook called from the OMAP idle loop.

While the activity timer is active, the smart-idle mode of the UART is
also disabled.  This is due to a "feature" of the UART module that
after a UART wakeup, the smart-idle mode may be entered before the
UART has communicated the interrupt, or upon TX, an idle mode may be
entered before the TX FIFOs are emptied.

Upon suspend, the 'prepare_suspend' hook cancels any pending activity
timers and allows the clocks to be disabled immediately.

In addition, upon disabling clocks the UART state is saved in case
of an off-mode transition while clocks are off.

Special thanks to Tero Kristo for the initial ideas and first versions
of UART idle support, and to Jouni Hogander for extra testing and
bugfixes.

Tested on OMAP3 (Beagle, RX51, SDP, EVM) and OMAP2 (n810)

Cc: Tero Kristo <tero.kristo@nokia.com>
Cc: Jouni Hogander <jouni.hogander@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
2009-05-28 10:59:06 -07:00

550 lines
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/*
* OMAP2 Power Management Routines
*
* Copyright (C) 2005 Texas Instruments, Inc.
* Copyright (C) 2006-2008 Nokia Corporation
*
* Written by:
* Richard Woodruff <r-woodruff2@ti.com>
* Tony Lindgren
* Juha Yrjola
* Amit Kucheria <amit.kucheria@nokia.com>
* Igor Stoppa <igor.stoppa@nokia.com>
*
* Based on pm.c for omap1
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/suspend.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/interrupt.h>
#include <linux/sysfs.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/time.h>
#include <linux/gpio.h>
#include <asm/mach/time.h>
#include <asm/mach/irq.h>
#include <asm/mach-types.h>
#include <mach/irqs.h>
#include <mach/clock.h>
#include <mach/sram.h>
#include <mach/control.h>
#include <mach/mux.h>
#include <mach/dma.h>
#include <mach/board.h>
#include "prm.h"
#include "prm-regbits-24xx.h"
#include "cm.h"
#include "cm-regbits-24xx.h"
#include "sdrc.h"
#include "pm.h"
#include <mach/powerdomain.h>
#include <mach/clockdomain.h>
static void (*omap2_sram_idle)(void);
static void (*omap2_sram_suspend)(u32 dllctrl, void __iomem *sdrc_dlla_ctrl,
void __iomem *sdrc_power);
static struct powerdomain *mpu_pwrdm;
static struct powerdomain *core_pwrdm;
static struct clockdomain *dsp_clkdm;
static struct clockdomain *gfx_clkdm;
static struct clk *osc_ck, *emul_ck;
static int omap2_fclks_active(void)
{
u32 f1, f2;
f1 = cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
f2 = cm_read_mod_reg(CORE_MOD, OMAP24XX_CM_FCLKEN2);
/* Ignore UART clocks. These are handled by UART core (serial.c) */
f1 &= ~(OMAP24XX_EN_UART1 | OMAP24XX_EN_UART2);
f2 &= ~OMAP24XX_EN_UART3;
if (f1 | f2)
return 1;
return 0;
}
static void omap2_enter_full_retention(void)
{
u32 l;
struct timespec ts_preidle, ts_postidle, ts_idle;
/* There is 1 reference hold for all children of the oscillator
* clock, the following will remove it. If no one else uses the
* oscillator itself it will be disabled if/when we enter retention
* mode.
*/
clk_disable(osc_ck);
/* Clear old wake-up events */
/* REVISIT: These write to reserved bits? */
prm_write_mod_reg(0xffffffff, CORE_MOD, PM_WKST1);
prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP24XX_PM_WKST2);
prm_write_mod_reg(0xffffffff, WKUP_MOD, PM_WKST);
/*
* Set MPU powerdomain's next power state to RETENTION;
* preserve logic state during retention
*/
pwrdm_set_logic_retst(mpu_pwrdm, PWRDM_POWER_RET);
pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_RET);
/* Workaround to kill USB */
l = omap_ctrl_readl(OMAP2_CONTROL_DEVCONF0) | OMAP24XX_USBSTANDBYCTRL;
omap_ctrl_writel(l, OMAP2_CONTROL_DEVCONF0);
omap2_gpio_prepare_for_retention();
if (omap2_pm_debug) {
omap2_pm_dump(0, 0, 0);
getnstimeofday(&ts_preidle);
}
/* One last check for pending IRQs to avoid extra latency due
* to sleeping unnecessarily. */
if (omap_irq_pending())
goto no_sleep;
omap_uart_prepare_idle(0);
omap_uart_prepare_idle(1);
omap_uart_prepare_idle(2);
/* Jump to SRAM suspend code */
omap2_sram_suspend(sdrc_read_reg(SDRC_DLLA_CTRL),
OMAP_SDRC_REGADDR(SDRC_DLLA_CTRL),
OMAP_SDRC_REGADDR(SDRC_POWER));
omap_uart_resume_idle(2);
omap_uart_resume_idle(1);
omap_uart_resume_idle(0);
no_sleep:
if (omap2_pm_debug) {
unsigned long long tmp;
getnstimeofday(&ts_postidle);
ts_idle = timespec_sub(ts_postidle, ts_preidle);
tmp = timespec_to_ns(&ts_idle) * NSEC_PER_USEC;
omap2_pm_dump(0, 1, tmp);
}
omap2_gpio_resume_after_retention();
clk_enable(osc_ck);
/* clear CORE wake-up events */
prm_write_mod_reg(0xffffffff, CORE_MOD, PM_WKST1);
prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP24XX_PM_WKST2);
/* wakeup domain events - bit 1: GPT1, bit5 GPIO */
prm_clear_mod_reg_bits(0x4 | 0x1, WKUP_MOD, PM_WKST);
/* MPU domain wake events */
l = prm_read_mod_reg(OCP_MOD, OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
if (l & 0x01)
prm_write_mod_reg(0x01, OCP_MOD,
OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
if (l & 0x20)
prm_write_mod_reg(0x20, OCP_MOD,
OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
/* Mask future PRCM-to-MPU interrupts */
prm_write_mod_reg(0x0, OCP_MOD, OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
}
static int omap2_i2c_active(void)
{
u32 l;
l = cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
return l & (OMAP2420_EN_I2C2 | OMAP2420_EN_I2C1);
}
static int sti_console_enabled;
static int omap2_allow_mpu_retention(void)
{
u32 l;
/* Check for MMC, UART2, UART1, McSPI2, McSPI1 and DSS1. */
l = cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
if (l & (OMAP2420_EN_MMC | OMAP24XX_EN_UART2 |
OMAP24XX_EN_UART1 | OMAP24XX_EN_MCSPI2 |
OMAP24XX_EN_MCSPI1 | OMAP24XX_EN_DSS1))
return 0;
/* Check for UART3. */
l = cm_read_mod_reg(CORE_MOD, OMAP24XX_CM_FCLKEN2);
if (l & OMAP24XX_EN_UART3)
return 0;
if (sti_console_enabled)
return 0;
return 1;
}
static void omap2_enter_mpu_retention(void)
{
int only_idle = 0;
struct timespec ts_preidle, ts_postidle, ts_idle;
/* Putting MPU into the WFI state while a transfer is active
* seems to cause the I2C block to timeout. Why? Good question. */
if (omap2_i2c_active())
return;
/* The peripherals seem not to be able to wake up the MPU when
* it is in retention mode. */
if (omap2_allow_mpu_retention()) {
/* REVISIT: These write to reserved bits? */
prm_write_mod_reg(0xffffffff, CORE_MOD, PM_WKST1);
prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP24XX_PM_WKST2);
prm_write_mod_reg(0xffffffff, WKUP_MOD, PM_WKST);
/* Try to enter MPU retention */
prm_write_mod_reg((0x01 << OMAP_POWERSTATE_SHIFT) |
OMAP_LOGICRETSTATE,
MPU_MOD, PM_PWSTCTRL);
} else {
/* Block MPU retention */
prm_write_mod_reg(OMAP_LOGICRETSTATE, MPU_MOD, PM_PWSTCTRL);
only_idle = 1;
}
if (omap2_pm_debug) {
omap2_pm_dump(only_idle ? 2 : 1, 0, 0);
getnstimeofday(&ts_preidle);
}
omap2_sram_idle();
if (omap2_pm_debug) {
unsigned long long tmp;
getnstimeofday(&ts_postidle);
ts_idle = timespec_sub(ts_postidle, ts_preidle);
tmp = timespec_to_ns(&ts_idle) * NSEC_PER_USEC;
omap2_pm_dump(only_idle ? 2 : 1, 1, tmp);
}
}
static int omap2_can_sleep(void)
{
if (omap2_fclks_active())
return 0;
if (osc_ck->usecount > 1)
return 0;
if (omap_dma_running())
return 0;
return 1;
}
static void omap2_pm_idle(void)
{
local_irq_disable();
local_fiq_disable();
if (!omap2_can_sleep()) {
if (omap_irq_pending())
goto out;
omap2_enter_mpu_retention();
goto out;
}
if (omap_irq_pending())
goto out;
omap2_enter_full_retention();
out:
local_fiq_enable();
local_irq_enable();
}
static int omap2_pm_prepare(void)
{
/* We cannot sleep in idle until we have resumed */
disable_hlt();
return 0;
}
static int omap2_pm_suspend(void)
{
u32 wken_wkup, mir1;
wken_wkup = prm_read_mod_reg(WKUP_MOD, PM_WKEN);
prm_write_mod_reg(wken_wkup & ~OMAP24XX_EN_GPT1, WKUP_MOD, PM_WKEN);
/* Mask GPT1 */
mir1 = omap_readl(0x480fe0a4);
omap_writel(1 << 5, 0x480fe0ac);
omap_uart_prepare_suspend();
omap2_enter_full_retention();
omap_writel(mir1, 0x480fe0a4);
prm_write_mod_reg(wken_wkup, WKUP_MOD, PM_WKEN);
return 0;
}
static int omap2_pm_enter(suspend_state_t state)
{
int ret = 0;
switch (state) {
case PM_SUSPEND_STANDBY:
case PM_SUSPEND_MEM:
ret = omap2_pm_suspend();
break;
default:
ret = -EINVAL;
}
return ret;
}
static void omap2_pm_finish(void)
{
enable_hlt();
}
static struct platform_suspend_ops omap_pm_ops = {
.prepare = omap2_pm_prepare,
.enter = omap2_pm_enter,
.finish = omap2_pm_finish,
.valid = suspend_valid_only_mem,
};
static int _pm_clkdm_enable_hwsup(struct clockdomain *clkdm)
{
omap2_clkdm_allow_idle(clkdm);
return 0;
}
static void __init prcm_setup_regs(void)
{
int i, num_mem_banks;
struct powerdomain *pwrdm;
/* Enable autoidle */
prm_write_mod_reg(OMAP24XX_AUTOIDLE, OCP_MOD,
OMAP2_PRCM_SYSCONFIG_OFFSET);
/* Set all domain wakeup dependencies */
prm_write_mod_reg(OMAP_EN_WKUP_MASK, MPU_MOD, PM_WKDEP);
prm_write_mod_reg(0, OMAP24XX_DSP_MOD, PM_WKDEP);
prm_write_mod_reg(0, GFX_MOD, PM_WKDEP);
prm_write_mod_reg(0, CORE_MOD, PM_WKDEP);
if (cpu_is_omap2430())
prm_write_mod_reg(0, OMAP2430_MDM_MOD, PM_WKDEP);
/*
* Set CORE powerdomain memory banks to retain their contents
* during RETENTION
*/
num_mem_banks = pwrdm_get_mem_bank_count(core_pwrdm);
for (i = 0; i < num_mem_banks; i++)
pwrdm_set_mem_retst(core_pwrdm, i, PWRDM_POWER_RET);
/* Set CORE powerdomain's next power state to RETENTION */
pwrdm_set_next_pwrst(core_pwrdm, PWRDM_POWER_RET);
/*
* Set MPU powerdomain's next power state to RETENTION;
* preserve logic state during retention
*/
pwrdm_set_logic_retst(mpu_pwrdm, PWRDM_POWER_RET);
pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_RET);
/* Force-power down DSP, GFX powerdomains */
pwrdm = clkdm_get_pwrdm(dsp_clkdm);
pwrdm_set_next_pwrst(pwrdm, PWRDM_POWER_OFF);
omap2_clkdm_sleep(dsp_clkdm);
pwrdm = clkdm_get_pwrdm(gfx_clkdm);
pwrdm_set_next_pwrst(pwrdm, PWRDM_POWER_OFF);
omap2_clkdm_sleep(gfx_clkdm);
/* Enable clockdomain hardware-supervised control for all clkdms */
clkdm_for_each(_pm_clkdm_enable_hwsup);
/* Enable clock autoidle for all domains */
cm_write_mod_reg(OMAP24XX_AUTO_CAM |
OMAP24XX_AUTO_MAILBOXES |
OMAP24XX_AUTO_WDT4 |
OMAP2420_AUTO_WDT3 |
OMAP24XX_AUTO_MSPRO |
OMAP2420_AUTO_MMC |
OMAP24XX_AUTO_FAC |
OMAP2420_AUTO_EAC |
OMAP24XX_AUTO_HDQ |
OMAP24XX_AUTO_UART2 |
OMAP24XX_AUTO_UART1 |
OMAP24XX_AUTO_I2C2 |
OMAP24XX_AUTO_I2C1 |
OMAP24XX_AUTO_MCSPI2 |
OMAP24XX_AUTO_MCSPI1 |
OMAP24XX_AUTO_MCBSP2 |
OMAP24XX_AUTO_MCBSP1 |
OMAP24XX_AUTO_GPT12 |
OMAP24XX_AUTO_GPT11 |
OMAP24XX_AUTO_GPT10 |
OMAP24XX_AUTO_GPT9 |
OMAP24XX_AUTO_GPT8 |
OMAP24XX_AUTO_GPT7 |
OMAP24XX_AUTO_GPT6 |
OMAP24XX_AUTO_GPT5 |
OMAP24XX_AUTO_GPT4 |
OMAP24XX_AUTO_GPT3 |
OMAP24XX_AUTO_GPT2 |
OMAP2420_AUTO_VLYNQ |
OMAP24XX_AUTO_DSS,
CORE_MOD, CM_AUTOIDLE1);
cm_write_mod_reg(OMAP24XX_AUTO_UART3 |
OMAP24XX_AUTO_SSI |
OMAP24XX_AUTO_USB,
CORE_MOD, CM_AUTOIDLE2);
cm_write_mod_reg(OMAP24XX_AUTO_SDRC |
OMAP24XX_AUTO_GPMC |
OMAP24XX_AUTO_SDMA,
CORE_MOD, CM_AUTOIDLE3);
cm_write_mod_reg(OMAP24XX_AUTO_PKA |
OMAP24XX_AUTO_AES |
OMAP24XX_AUTO_RNG |
OMAP24XX_AUTO_SHA |
OMAP24XX_AUTO_DES,
CORE_MOD, OMAP24XX_CM_AUTOIDLE4);
cm_write_mod_reg(OMAP2420_AUTO_DSP_IPI, OMAP24XX_DSP_MOD, CM_AUTOIDLE);
/* Put DPLL and both APLLs into autoidle mode */
cm_write_mod_reg((0x03 << OMAP24XX_AUTO_DPLL_SHIFT) |
(0x03 << OMAP24XX_AUTO_96M_SHIFT) |
(0x03 << OMAP24XX_AUTO_54M_SHIFT),
PLL_MOD, CM_AUTOIDLE);
cm_write_mod_reg(OMAP24XX_AUTO_OMAPCTRL |
OMAP24XX_AUTO_WDT1 |
OMAP24XX_AUTO_MPU_WDT |
OMAP24XX_AUTO_GPIOS |
OMAP24XX_AUTO_32KSYNC |
OMAP24XX_AUTO_GPT1,
WKUP_MOD, CM_AUTOIDLE);
/* REVISIT: Configure number of 32 kHz clock cycles for sys_clk
* stabilisation */
prm_write_mod_reg(15 << OMAP_SETUP_TIME_SHIFT, OMAP24XX_GR_MOD,
OMAP2_PRCM_CLKSSETUP_OFFSET);
/* Configure automatic voltage transition */
prm_write_mod_reg(2 << OMAP_SETUP_TIME_SHIFT, OMAP24XX_GR_MOD,
OMAP2_PRCM_VOLTSETUP_OFFSET);
prm_write_mod_reg(OMAP24XX_AUTO_EXTVOLT |
(0x1 << OMAP24XX_SETOFF_LEVEL_SHIFT) |
OMAP24XX_MEMRETCTRL |
(0x1 << OMAP24XX_SETRET_LEVEL_SHIFT) |
(0x0 << OMAP24XX_VOLT_LEVEL_SHIFT),
OMAP24XX_GR_MOD, OMAP2_PRCM_VOLTCTRL_OFFSET);
/* Enable wake-up events */
prm_write_mod_reg(OMAP24XX_EN_GPIOS | OMAP24XX_EN_GPT1,
WKUP_MOD, PM_WKEN);
}
int __init omap2_pm_init(void)
{
u32 l;
if (!cpu_is_omap24xx())
return -ENODEV;
printk(KERN_INFO "Power Management for OMAP2 initializing\n");
l = prm_read_mod_reg(OCP_MOD, OMAP2_PRCM_REVISION_OFFSET);
printk(KERN_INFO "PRCM revision %d.%d\n", (l >> 4) & 0x0f, l & 0x0f);
/* Look up important powerdomains, clockdomains */
mpu_pwrdm = pwrdm_lookup("mpu_pwrdm");
if (!mpu_pwrdm)
pr_err("PM: mpu_pwrdm not found\n");
core_pwrdm = pwrdm_lookup("core_pwrdm");
if (!core_pwrdm)
pr_err("PM: core_pwrdm not found\n");
dsp_clkdm = clkdm_lookup("dsp_clkdm");
if (!dsp_clkdm)
pr_err("PM: mpu_clkdm not found\n");
gfx_clkdm = clkdm_lookup("gfx_clkdm");
if (!gfx_clkdm)
pr_err("PM: gfx_clkdm not found\n");
osc_ck = clk_get(NULL, "osc_ck");
if (IS_ERR(osc_ck)) {
printk(KERN_ERR "could not get osc_ck\n");
return -ENODEV;
}
if (cpu_is_omap242x()) {
emul_ck = clk_get(NULL, "emul_ck");
if (IS_ERR(emul_ck)) {
printk(KERN_ERR "could not get emul_ck\n");
clk_put(osc_ck);
return -ENODEV;
}
}
prcm_setup_regs();
/* Hack to prevent MPU retention when STI console is enabled. */
{
const struct omap_sti_console_config *sti;
sti = omap_get_config(OMAP_TAG_STI_CONSOLE,
struct omap_sti_console_config);
if (sti != NULL && sti->enable)
sti_console_enabled = 1;
}
/*
* We copy the assembler sleep/wakeup routines to SRAM.
* These routines need to be in SRAM as that's the only
* memory the MPU can see when it wakes up.
*/
if (cpu_is_omap24xx()) {
omap2_sram_idle = omap_sram_push(omap24xx_idle_loop_suspend,
omap24xx_idle_loop_suspend_sz);
omap2_sram_suspend = omap_sram_push(omap24xx_cpu_suspend,
omap24xx_cpu_suspend_sz);
}
suspend_set_ops(&omap_pm_ops);
pm_idle = omap2_pm_idle;
return 0;
}
late_initcall(omap2_pm_init);
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