[POWERPC] MPC5200 low power mode

Low-power mode implementation for Lite5200b.
Some I/O registers are also saved here.

A recent U-Boot that supports this (lite5200b_PM_config) is needed.

Signed-off-by: Domen Puncer <domen.puncer@telargo.com>
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/52xx/Makefile

@@ -10,3 +10,6 @@ obj-$(CONFIG_PPC_EFIKA)		+= efika.o
 obj-$(CONFIG_PPC_LITE5200)	+= lite5200.o
 
 obj-$(CONFIG_PM)		+= mpc52xx_sleep.o mpc52xx_pm.o
+ifeq ($(CONFIG_PPC_LITE5200),y)
+	obj-$(CONFIG_PM)	+= lite5200_sleep.o lite5200_pm.o
+endif

arch/powerpc/platforms/52xx/lite5200.c

@@ -85,7 +85,6 @@ lite5200_setup_cpu(void)
 }
 
 #ifdef CONFIG_PM
-static u32 descr_a;
 static void lite5200_suspend_prepare(void __iomem *mbar)
 {
 	u8 pin = 1;	/* GPIO_WKUP_1 (GPIO_PSC2_4) */
@@ -96,13 +95,18 @@ static void lite5200_suspend_prepare(void __iomem *mbar)
 	 * power down usb port
 	 * this needs to be called before of-ohci suspend code
 	 */
-	descr_a = in_be32(mbar + 0x1048);
-	out_be32(mbar + 0x1048, (descr_a & ~0x200) | 0x100);
+
+	/* set ports to "power switched" and "powered at the same time"
+	 * USB Rh descriptor A: NPS = 0, PSM = 0 */
+	out_be32(mbar + 0x1048, in_be32(mbar + 0x1048) & ~0x300);
+	/* USB Rh status: LPS = 1 - turn off power */
+	out_be32(mbar + 0x1050, 0x00000001);
 }
 
 static void lite5200_resume_finish(void __iomem *mbar)
 {
-	out_be32(mbar + 0x1048, descr_a);
+	/* USB Rh status: LPSC = 1 - turn on power */
+	out_be32(mbar + 0x1050, 0x00010000);
 }
 #endif
 
@@ -122,7 +126,7 @@ static void __init lite5200_setup_arch(void)
 #ifdef CONFIG_PM
 	mpc52xx_suspend.board_suspend_prepare = lite5200_suspend_prepare;
 	mpc52xx_suspend.board_resume_finish = lite5200_resume_finish;
-	mpc52xx_pm_init();
+	lite5200_pm_init();
 #endif
 
 #ifdef CONFIG_PCI

arch/powerpc/platforms/52xx/lite5200_pm.c

@@ -0,0 +1,213 @@
+#include <linux/init.h>
+#include <linux/pm.h>
+#include <asm/io.h>
+#include <asm/time.h>
+#include <asm/mpc52xx.h>
+#include "mpc52xx_pic.h"
+
+/* defined in lite5200_sleep.S and only used here */
+extern void lite5200_low_power(void __iomem *sram, void __iomem *mbar);
+
+static struct mpc52xx_cdm __iomem *cdm;
+static struct mpc52xx_intr __iomem *pic;
+static struct mpc52xx_sdma __iomem *bes;
+static struct mpc52xx_xlb __iomem *xlb;
+static struct mpc52xx_gpio __iomem *gps;
+static struct mpc52xx_gpio_wkup __iomem *gpw;
+static void __iomem *sram;
+static const int sram_size = 0x4000;	/* 16 kBytes */
+static void __iomem *mbar;
+
+static int lite5200_pm_valid(suspend_state_t state)
+{
+	switch (state) {
+	case PM_SUSPEND_STANDBY:
+	case PM_SUSPEND_MEM:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+static int lite5200_pm_prepare(suspend_state_t state)
+{
+	/* deep sleep? let mpc52xx code handle that */
+	if (state == PM_SUSPEND_STANDBY)
+		return mpc52xx_pm_prepare(state);
+
+	if (state != PM_SUSPEND_MEM)
+		return -EINVAL;
+
+	/* map registers */
+	mbar = mpc52xx_find_and_map("mpc5200");
+	if (!mbar) {
+		printk(KERN_ERR "%s:%i Error mapping registers\n", __func__, __LINE__);
+		return -ENOSYS;
+	}
+
+	cdm = mbar + 0x200;
+	pic = mbar + 0x500;
+	gps = mbar + 0xb00;
+	gpw = mbar + 0xc00;
+	bes = mbar + 0x1200;
+	xlb = mbar + 0x1f00;
+	sram = mbar + 0x8000;
+
+	return 0;
+}
+
+/* save and restore registers not bound to any real devices */
+static struct mpc52xx_cdm scdm;
+static struct mpc52xx_intr spic;
+static struct mpc52xx_sdma sbes;
+static struct mpc52xx_xlb sxlb;
+static struct mpc52xx_gpio sgps;
+static struct mpc52xx_gpio_wkup sgpw;
+
+static void lite5200_save_regs(void)
+{
+	_memcpy_fromio(&spic, pic, sizeof(*pic));
+	_memcpy_fromio(&sbes, bes, sizeof(*bes));
+	_memcpy_fromio(&scdm, cdm, sizeof(*cdm));
+	_memcpy_fromio(&sxlb, xlb, sizeof(*xlb));
+	_memcpy_fromio(&sgps, gps, sizeof(*gps));
+	_memcpy_fromio(&sgpw, gpw, sizeof(*gpw));
+
+	_memcpy_fromio(saved_sram, sram, sram_size);
+}
+
+static void lite5200_restore_regs(void)
+{
+	int i;
+	_memcpy_toio(sram, saved_sram, sram_size);
+
+
+	/*
+	 * GPIOs. Interrupt Master Enable has higher address then other
+	 * registers, so just memcpy is ok.
+	 */
+	_memcpy_toio(gpw, &sgpw, sizeof(*gpw));
+	_memcpy_toio(gps, &sgps, sizeof(*gps));
+
+
+	/* XLB Arbitrer */
+	out_be32(&xlb->snoop_window, sxlb.snoop_window);
+	out_be32(&xlb->master_priority, sxlb.master_priority);
+	out_be32(&xlb->master_pri_enable, sxlb.master_pri_enable);
+
+	/* enable */
+	out_be32(&xlb->int_enable, sxlb.int_enable);
+	out_be32(&xlb->config, sxlb.config);
+
+
+	/* CDM - Clock Distribution Module */
+	out_8(&cdm->ipb_clk_sel, scdm.ipb_clk_sel);
+	out_8(&cdm->pci_clk_sel, scdm.pci_clk_sel);
+
+	out_8(&cdm->ext_48mhz_en, scdm.ext_48mhz_en);
+	out_8(&cdm->fd_enable, scdm.fd_enable);
+	out_be16(&cdm->fd_counters, scdm.fd_counters);
+
+	out_be32(&cdm->clk_enables, scdm.clk_enables);
+
+	out_8(&cdm->osc_disable, scdm.osc_disable);
+
+	out_be16(&cdm->mclken_div_psc1, scdm.mclken_div_psc1);
+	out_be16(&cdm->mclken_div_psc2, scdm.mclken_div_psc2);
+	out_be16(&cdm->mclken_div_psc3, scdm.mclken_div_psc3);
+	out_be16(&cdm->mclken_div_psc6, scdm.mclken_div_psc6);
+
+
+	/* BESTCOMM */
+	out_be32(&bes->taskBar, sbes.taskBar);
+	out_be32(&bes->currentPointer, sbes.currentPointer);
+	out_be32(&bes->endPointer, sbes.endPointer);
+	out_be32(&bes->variablePointer, sbes.variablePointer);
+
+	out_8(&bes->IntVect1, sbes.IntVect1);
+	out_8(&bes->IntVect2, sbes.IntVect2);
+	out_be16(&bes->PtdCntrl, sbes.PtdCntrl);
+
+	for (i=0; i<32; i++)
+		out_8(&bes->ipr[i], sbes.ipr[i]);
+
+	out_be32(&bes->cReqSelect, sbes.cReqSelect);
+	out_be32(&bes->task_size0, sbes.task_size0);
+	out_be32(&bes->task_size1, sbes.task_size1);
+	out_be32(&bes->MDEDebug, sbes.MDEDebug);
+	out_be32(&bes->ADSDebug, sbes.ADSDebug);
+	out_be32(&bes->Value1, sbes.Value1);
+	out_be32(&bes->Value2, sbes.Value2);
+	out_be32(&bes->Control, sbes.Control);
+	out_be32(&bes->Status, sbes.Status);
+	out_be32(&bes->PTDDebug, sbes.PTDDebug);
+
+	/* restore tasks */
+	for (i=0; i<16; i++)
+		out_be16(&bes->tcr[i], sbes.tcr[i]);
+
+	/* enable interrupts */
+	out_be32(&bes->IntPend, sbes.IntPend);
+	out_be32(&bes->IntMask, sbes.IntMask);
+
+
+	/* PIC */
+	out_be32(&pic->per_pri1, spic.per_pri1);
+	out_be32(&pic->per_pri2, spic.per_pri2);
+	out_be32(&pic->per_pri3, spic.per_pri3);
+
+	out_be32(&pic->main_pri1, spic.main_pri1);
+	out_be32(&pic->main_pri2, spic.main_pri2);
+
+	out_be32(&pic->enc_status, spic.enc_status);
+
+	/* unmask and enable interrupts */
+	out_be32(&pic->per_mask, spic.per_mask);
+	out_be32(&pic->main_mask, spic.main_mask);
+	out_be32(&pic->ctrl, spic.ctrl);
+}
+
+static int lite5200_pm_enter(suspend_state_t state)
+{
+	/* deep sleep? let mpc52xx code handle that */
+	if (state == PM_SUSPEND_STANDBY) {
+		return mpc52xx_pm_enter(state);
+	}
+
+	lite5200_save_regs();
+
+	/* effectively save FP regs */
+	enable_kernel_fp();
+
+	lite5200_low_power(sram, mbar);
+
+	lite5200_restore_regs();
+
+	/* restart jiffies */
+	wakeup_decrementer();
+
+	iounmap(mbar);
+	return 0;
+}
+
+static int lite5200_pm_finish(suspend_state_t state)
+{
+	/* deep sleep? let mpc52xx code handle that */
+	if (state == PM_SUSPEND_STANDBY) {
+		return mpc52xx_pm_finish(state);
+	}
+	return 0;
+}
+
+static struct pm_ops lite5200_pm_ops = {
+	.valid		= lite5200_pm_valid,
+	.prepare	= lite5200_pm_prepare,
+	.enter		= lite5200_pm_enter,
+	.finish		= lite5200_pm_finish,
+};
+
+int __init lite5200_pm_init(void)
+{
+	pm_set_ops(&lite5200_pm_ops);
+	return 0;
+}