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[22/35] davinci: add power management support

Message ID 1262802737-6601-23-git-send-email-khilman@deeprootsystems.com (mailing list archive)
State Accepted
Headers show

Commit Message

Kevin Hilman Jan. 6, 2010, 6:32 p.m. UTC
None
diff mbox

Patch

diff --git a/arch/arm/mach-davinci/Makefile b/arch/arm/mach-davinci/Makefile
index eeb9230..d0fed3a 100644
--- a/arch/arm/mach-davinci/Makefile
+++ b/arch/arm/mach-davinci/Makefile
@@ -34,3 +34,4 @@  obj-$(CONFIG_MACH_DAVINCI_DA850_EVM)	+= board-da850-evm.o
 # Power Management
 obj-$(CONFIG_CPU_FREQ)			+= cpufreq.o
 obj-$(CONFIG_CPU_IDLE)			+= cpuidle.o
+obj-$(CONFIG_SUSPEND)			+= pm.o sleep.o
diff --git a/arch/arm/mach-davinci/include/mach/memory.h b/arch/arm/mach-davinci/include/mach/memory.h
index 7aeaf46..a91edfb 100644
--- a/arch/arm/mach-davinci/include/mach/memory.h
+++ b/arch/arm/mach-davinci/include/mach/memory.h
@@ -33,6 +33,7 @@ 
 
 #define DDR2_SDRCR_OFFSET	0xc
 #define DDR2_SRPD_BIT		BIT(23)
+#define DDR2_MCLKSTOPEN_BIT	BIT(30)
 #define DDR2_LPMODEN_BIT	BIT(31)
 
 /*
diff --git a/arch/arm/mach-davinci/include/mach/pm.h b/arch/arm/mach-davinci/include/mach/pm.h
new file mode 100644
index 0000000..37b19bf
--- /dev/null
+++ b/arch/arm/mach-davinci/include/mach/pm.h
@@ -0,0 +1,54 @@ 
+/*
+ * TI DaVinci platform support for power management.
+ *
+ * Copyright (C) 2009 Texas Instruments, Inc. http://www.ti.com/
+ *
+ * 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.
+ */
+#ifndef _MACH_DAVINCI_PM_H
+#define _MACH_DAVINCI_PM_H
+
+/*
+ * Caution: Assembly code in sleep.S makes assumtion on the order
+ * of the members of this structure.
+ */
+struct davinci_pm_config {
+	void __iomem *ddr2_ctlr_base;
+	void __iomem *ddrpsc_reg_base;
+	int ddrpsc_num;
+	void __iomem *ddrpll_reg_base;
+	void __iomem *deepsleep_reg;
+	void __iomem *cpupll_reg_base;
+	/*
+	 * Note on SLEEPCOUNT:
+	 * The SLEEPCOUNT feature is mainly intended for cases in which
+	 * the internal oscillator is used. The internal oscillator is
+	 * fully disabled in deep sleep mode.  When you exist deep sleep
+	 * mode, the oscillator will be turned on and will generate very
+	 * small oscillations which will not be detected by the deep sleep
+	 * counter.  Eventually those oscillations will grow to an amplitude
+	 * large enough to start incrementing the deep sleep counter.
+	 * In this case recommendation from hardware engineers is that the
+	 * SLEEPCOUNT be set to 4096.  This means that 4096 valid clock cycles
+	 * must be detected before the clock is passed to the rest of the
+	 * system.
+	 * In the case that the internal oscillator is not used and the
+	 * clock is generated externally, the SLEEPCOUNT value can be very
+	 * small since the clock input is assumed to be stable before SoC
+	 * is taken out of deepsleep mode.  A value of 128 would be more than
+	 * adequate.
+	 */
+	int sleepcount;
+};
+
+extern unsigned int davinci_cpu_suspend_sz;
+extern void davinci_cpu_suspend(struct davinci_pm_config *);
+
+#endif
diff --git a/arch/arm/mach-davinci/pm.c b/arch/arm/mach-davinci/pm.c
new file mode 100644
index 0000000..fab953b
--- /dev/null
+++ b/arch/arm/mach-davinci/pm.c
@@ -0,0 +1,158 @@ 
+/*
+ * DaVinci Power Management Routines
+ *
+ * Copyright (C) 2009 Texas Instruments, Inc. http://www.ti.com/
+ *
+ * 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/pm.h>
+#include <linux/suspend.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/spinlock.h>
+
+#include <asm/cacheflush.h>
+#include <asm/delay.h>
+
+#include <mach/da8xx.h>
+#include <mach/sram.h>
+#include <mach/pm.h>
+
+#include "clock.h"
+
+#define DEEPSLEEP_SLEEPCOUNT_MASK	0xFFFF
+
+static void (*davinci_sram_suspend) (struct davinci_pm_config *);
+static struct davinci_pm_config *pdata;
+
+static void davinci_sram_push(void *dest, void *src, unsigned int size)
+{
+	memcpy(dest, src, size);
+	flush_icache_range((unsigned long)dest, (unsigned long)(dest + size));
+}
+
+static void davinci_pm_suspend(void)
+{
+	unsigned val;
+
+	if (pdata->cpupll_reg_base != pdata->ddrpll_reg_base) {
+
+		/* Switch CPU PLL to bypass mode */
+		val = __raw_readl(pdata->cpupll_reg_base + PLLCTL);
+		val &= ~(PLLCTL_PLLENSRC | PLLCTL_PLLEN);
+		__raw_writel(val, pdata->cpupll_reg_base + PLLCTL);
+
+		udelay(PLL_BYPASS_TIME);
+
+		/* Powerdown CPU PLL */
+		val = __raw_readl(pdata->cpupll_reg_base + PLLCTL);
+		val |= PLLCTL_PLLPWRDN;
+		__raw_writel(val, pdata->cpupll_reg_base + PLLCTL);
+	}
+
+	/* Configure sleep count in deep sleep register */
+	val = __raw_readl(pdata->deepsleep_reg);
+	val &= ~DEEPSLEEP_SLEEPCOUNT_MASK,
+	val |= pdata->sleepcount;
+	__raw_writel(val, pdata->deepsleep_reg);
+
+	/* System goes to sleep in this call */
+	davinci_sram_suspend(pdata);
+
+	if (pdata->cpupll_reg_base != pdata->ddrpll_reg_base) {
+
+		/* put CPU PLL in reset */
+		val = __raw_readl(pdata->cpupll_reg_base + PLLCTL);
+		val &= ~PLLCTL_PLLRST;
+		__raw_writel(val, pdata->cpupll_reg_base + PLLCTL);
+
+		/* put CPU PLL in power down */
+		val = __raw_readl(pdata->cpupll_reg_base + PLLCTL);
+		val &= ~PLLCTL_PLLPWRDN;
+		__raw_writel(val, pdata->cpupll_reg_base + PLLCTL);
+
+		/* wait for CPU PLL reset */
+		udelay(PLL_RESET_TIME);
+
+		/* bring CPU PLL out of reset */
+		val = __raw_readl(pdata->cpupll_reg_base + PLLCTL);
+		val |= PLLCTL_PLLRST;
+		__raw_writel(val, pdata->cpupll_reg_base + PLLCTL);
+
+		/* Wait for CPU PLL to lock */
+		udelay(PLL_LOCK_TIME);
+
+		/* Remove CPU PLL from bypass mode */
+		val = __raw_readl(pdata->cpupll_reg_base + PLLCTL);
+		val &= ~PLLCTL_PLLENSRC;
+		val |= PLLCTL_PLLEN;
+		__raw_writel(val, pdata->cpupll_reg_base + PLLCTL);
+	}
+}
+
+static int davinci_pm_enter(suspend_state_t state)
+{
+	int ret = 0;
+
+	switch (state) {
+	case PM_SUSPEND_STANDBY:
+	case PM_SUSPEND_MEM:
+		davinci_pm_suspend();
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static struct platform_suspend_ops davinci_pm_ops = {
+	.enter		= davinci_pm_enter,
+	.valid		= suspend_valid_only_mem,
+};
+
+static int __init davinci_pm_probe(struct platform_device *pdev)
+{
+	pdata = pdev->dev.platform_data;
+	if (!pdata) {
+		dev_err(&pdev->dev, "cannot get platform data\n");
+		return -ENOENT;
+	}
+
+	davinci_sram_suspend = sram_alloc(davinci_cpu_suspend_sz, NULL);
+	if (!davinci_sram_suspend) {
+		dev_err(&pdev->dev, "cannot allocate SRAM memory\n");
+		return -ENOMEM;
+	}
+
+	davinci_sram_push(davinci_sram_suspend, davinci_cpu_suspend,
+						davinci_cpu_suspend_sz);
+
+	suspend_set_ops(&davinci_pm_ops);
+
+	return 0;
+}
+
+static int __exit davinci_pm_remove(struct platform_device *pdev)
+{
+	sram_free(davinci_sram_suspend, davinci_cpu_suspend_sz);
+	return 0;
+}
+
+static struct platform_driver davinci_pm_driver = {
+	.driver = {
+		.name	 = "pm-davinci",
+		.owner	 = THIS_MODULE,
+	},
+	.remove = __exit_p(davinci_pm_remove),
+};
+
+static int __init davinci_pm_init(void)
+{
+	return platform_driver_probe(&davinci_pm_driver, davinci_pm_probe);
+}
+late_initcall(davinci_pm_init);
diff --git a/arch/arm/mach-davinci/sleep.S b/arch/arm/mach-davinci/sleep.S
new file mode 100644
index 0000000..fb5e72b
--- /dev/null
+++ b/arch/arm/mach-davinci/sleep.S
@@ -0,0 +1,224 @@ 
+/*
+ * (C) Copyright 2009, Texas Instruments, Inc. http://www.ti.com/
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/* replicated define because linux/bitops.h cannot be included in assembly */
+#define BIT(nr)			(1 << (nr))
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <mach/psc.h>
+#include <mach/memory.h>
+
+#include "clock.h"
+
+/* Arbitrary, hardware currently does not update PHYRDY correctly */
+#define PHYRDY_CYCLES		0x1000
+
+/* Assume 25 MHz speed for the cycle conversions since PLLs are bypassed */
+#define PLL_BYPASS_CYCLES	(PLL_BYPASS_TIME * 25)
+#define PLL_RESET_CYCLES	(PLL_RESET_TIME	* 25)
+#define PLL_LOCK_CYCLES		(PLL_LOCK_TIME * 25)
+
+#define DEEPSLEEP_SLEEPENABLE_BIT	BIT(31)
+
+	.text
+/*
+ * Move DaVinci into deep sleep state
+ *
+ * Note: This code is copied to internal SRAM by PM code. When the DaVinci
+ *	 wakes up it continues execution at the point it went to sleep.
+ * Register Usage:
+ * 	r0: contains virtual base for DDR2 controller
+ * 	r1: contains virtual base for DDR2 Power and Sleep controller (PSC)
+ * 	r2: contains PSC number for DDR2
+ * 	r3: contains virtual base DDR2 PLL controller
+ * 	r4: contains virtual address of the DEEPSLEEP register
+ */
+ENTRY(davinci_cpu_suspend)
+	stmfd	sp!, {r0-r12, lr}		@ save registers on stack
+
+	ldr 	ip, CACHE_FLUSH
+	blx	ip
+
+	ldmia	r0, {r0-r4}
+
+	/*
+	 * Switch DDR to self-refresh mode.
+	 */
+
+	/* calculate SDRCR address */
+	ldr	ip, [r0, #DDR2_SDRCR_OFFSET]
+	bic	ip, ip, #DDR2_SRPD_BIT
+	orr	ip, ip, #DDR2_LPMODEN_BIT
+	str	ip, [r0, #DDR2_SDRCR_OFFSET]
+
+	ldr	ip, [r0, #DDR2_SDRCR_OFFSET]
+	orr	ip, ip, #DDR2_MCLKSTOPEN_BIT
+	str	ip, [r0, #DDR2_SDRCR_OFFSET]
+
+       mov	ip, #PHYRDY_CYCLES
+1:     subs	ip, ip, #0x1
+       bne	1b
+
+       /* Disable DDR2 LPSC */
+	mov	r7, r0
+	mov	r0, #0x2
+	bl davinci_ddr_psc_config
+	mov	r0, r7
+
+	/* Disable clock to DDR PHY */
+	ldr	ip, [r3, #PLLDIV1]
+	bic	ip, ip, #PLLDIV_EN
+	str	ip, [r3, #PLLDIV1]
+
+	/* Put the DDR PLL in bypass and power down */
+	ldr	ip, [r3, #PLLCTL]
+	bic	ip, ip, #PLLCTL_PLLENSRC
+	bic	ip, ip, #PLLCTL_PLLEN
+	str	ip, [r3, #PLLCTL]
+
+	/* Wait for PLL to switch to bypass */
+       mov	ip, #PLL_BYPASS_CYCLES
+2:     subs	ip, ip, #0x1
+       bne	2b
+
+       /* Power down the PLL */
+	ldr	ip, [r3, #PLLCTL]
+	orr	ip, ip, #PLLCTL_PLLPWRDN
+	str	ip, [r3, #PLLCTL]
+
+	/* Go to deep sleep */
+	ldr	ip, [r4]
+	orr	ip, ip, #DEEPSLEEP_SLEEPENABLE_BIT
+	/* System goes to sleep beyond after this instruction */
+	str	ip, [r4]
+
+	/* Wake up from sleep */
+
+	/* Clear sleep enable */
+	ldr	ip, [r4]
+	bic	ip, ip, #DEEPSLEEP_SLEEPENABLE_BIT
+	str	ip, [r4]
+
+	/* initialize the DDR PLL controller */
+
+	/* Put PLL in reset */
+	ldr	ip, [r3, #PLLCTL]
+	bic	ip, ip, #PLLCTL_PLLRST
+	str	ip, [r3, #PLLCTL]
+
+	/* Clear PLL power down */
+	ldr	ip, [r3, #PLLCTL]
+	bic	ip, ip, #PLLCTL_PLLPWRDN
+	str	ip, [r3, #PLLCTL]
+
+       mov	ip, #PLL_RESET_CYCLES
+3:     subs	ip, ip, #0x1
+       bne	3b
+
+       /* Bring PLL out of reset */
+	ldr	ip, [r3, #PLLCTL]
+	orr	ip, ip, #PLLCTL_PLLRST
+	str	ip, [r3, #PLLCTL]
+
+	/* Wait for PLL to lock (assume prediv = 1, 25MHz OSCIN) */
+       mov	ip, #PLL_LOCK_CYCLES
+4:     subs	ip, ip, #0x1
+       bne	4b
+
+       /* Remove PLL from bypass mode */
+	ldr	ip, [r3, #PLLCTL]
+	bic	ip, ip, #PLLCTL_PLLENSRC
+	orr	ip, ip, #PLLCTL_PLLEN
+	str	ip, [r3, #PLLCTL]
+
+	/* Start 2x clock to DDR2 */
+
+	ldr	ip, [r3, #PLLDIV1]
+	orr	ip, ip, #PLLDIV_EN
+	str	ip, [r3, #PLLDIV1]
+
+	/* Enable VCLK */
+
+       /* Enable DDR2 LPSC */
+	mov	r7, r0
+	mov	r0, #0x3
+	bl davinci_ddr_psc_config
+	mov	r0, r7
+
+	/* clear  MCLKSTOPEN */
+
+	ldr	ip, [r0, #DDR2_SDRCR_OFFSET]
+	bic	ip, ip, #DDR2_MCLKSTOPEN_BIT
+	str	ip, [r0, #DDR2_SDRCR_OFFSET]
+
+	ldr	ip, [r0, #DDR2_SDRCR_OFFSET]
+	bic	ip, ip, #DDR2_LPMODEN_BIT
+	str	ip, [r0, #DDR2_SDRCR_OFFSET]
+
+	/* Restore registers and return */
+	ldmfd   sp!, {r0-r12, pc}
+
+ENDPROC(davinci_cpu_suspend)
+
+/*
+ * Disables or Enables DDR2 LPSC
+ * Register Usage:
+ * 	r0: Enable or Disable LPSC r0 = 0x3 => Enable, r0 = 0x2 => Disable LPSC
+ * 	r1: contains virtual base for DDR2 Power and Sleep controller (PSC)
+ * 	r2: contains PSC number for DDR2
+ */
+ENTRY(davinci_ddr_psc_config)
+	/* Set next state in mdctl for DDR2 */
+	mov	r6, #MDCTL
+	add	r6, r6, r2, lsl #2
+	ldr	ip, [r1, r6]
+	bic	ip, ip, #MDSTAT_STATE_MASK
+	orr	ip, ip, r0
+	str	ip, [r1, r6]
+
+	/* Enable the Power Domain Transition Command */
+	ldr	ip, [r1, #PTCMD]
+	orr	ip, ip, #0x1
+	str	ip, [r1, #PTCMD]
+
+	/* Check for Transition Complete (PTSTAT) */
+ptstat_done:
+	ldr	ip, [r1, #PTSTAT]
+	and	ip, ip, #0x1
+	cmp 	ip, #0x0
+	bne	ptstat_done
+
+	/* Check for DDR2 clock disable completion; */
+	mov	r6, #MDSTAT
+	add	r6, r6, r2, lsl #2
+ddr2clk_stop_done:
+	ldr	ip, [r1, r6]
+	and	ip, ip, #MDSTAT_STATE_MASK
+	cmp	ip, r0
+	bne	ddr2clk_stop_done
+
+	mov	pc, lr
+ENDPROC(davinci_ddr_psc_config)
+
+CACHE_FLUSH:
+	.word	arm926_flush_kern_cache_all
+
+ENTRY(davinci_cpu_suspend_sz)
+	.word	. - davinci_cpu_suspend
+ENDPROC(davinci_cpu_suspend_sz)