203 lines
5.9 KiB
Diff
203 lines
5.9 KiB
Diff
From: Paul Burton <paul.burton@imgtec.com>
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Date: Wed, 7 May 2014 12:20:57 +0100
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Subject: [2/5] MIPS: Malta: add suspend state entry code
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Origin: https://git.kernel.org/linus/b6911bba598f5d611f7fdbb87b5af7f1712dbe9d
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This patch introduces code which will enter a suspend state via the
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PIIX4. This can only be done when PCI support is enabled since it
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requires access to PCI I/O space and the generation of a special cycle
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on the PCI bus. In cases where PCI is disabled the mips_pm_suspend
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function will simply always return an error.
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Signed-off-by: Paul Burton <paul.burton@imgtec.com>
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Cc: linux-mips@linux-mips.org
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Patchwork: https://patchwork.linux-mips.org/patch/6905/
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Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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---
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arch/mips/Kconfig | 6 ++
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arch/mips/include/asm/mach-malta/malta-pm.h | 37 +++++++++++
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arch/mips/mti-malta/Makefile | 2 +
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arch/mips/mti-malta/malta-pm.c | 96 +++++++++++++++++++++++++++++
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4 files changed, 141 insertions(+)
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create mode 100644 arch/mips/include/asm/mach-malta/malta-pm.h
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create mode 100644 arch/mips/mti-malta/malta-pm.c
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diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
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index 4e49591..2f2020f 100644
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--- a/arch/mips/Kconfig
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+++ b/arch/mips/Kconfig
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@@ -1671,6 +1671,12 @@ config SYS_HAS_CPU_XLR
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config SYS_HAS_CPU_XLP
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bool
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+config MIPS_MALTA_PM
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+ depends on MIPS_MALTA
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+ depends on PCI
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+ bool
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+ default y
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+
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#
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# CPU may reorder R->R, R->W, W->R, W->W
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# Reordering beyond LL and SC is handled in WEAK_REORDERING_BEYOND_LLSC
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diff --git a/arch/mips/include/asm/mach-malta/malta-pm.h b/arch/mips/include/asm/mach-malta/malta-pm.h
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new file mode 100644
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index 0000000..c2c2e20
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--- /dev/null
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+++ b/arch/mips/include/asm/mach-malta/malta-pm.h
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@@ -0,0 +1,37 @@
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+/*
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+ * Copyright (C) 2014 Imagination Technologies
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+ * Author: Paul Burton <paul.burton@imgtec.com>
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+ *
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+ * This program is free software; you can redistribute it and/or modify it
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+ * under the terms of the GNU General Public License as published by the
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+ * Free Software Foundation; either version 2 of the License, or (at your
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+ * option) any later version.
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+ */
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+
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+#ifndef __ASM_MIPS_MACH_MALTA_PM_H__
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+#define __ASM_MIPS_MACH_MALTA_PM_H__
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+
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+#include <asm/mips-boards/piix4.h>
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+
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+#ifdef CONFIG_MIPS_MALTA_PM
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+
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+/**
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+ * mips_pm_suspend - enter a suspend state
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+ * @state: the state to enter, one of PIIX4_FUNC3IO_PMCNTRL_SUS_TYP_*
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+ *
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+ * Enters a suspend state via the Malta's PIIX4. If the state to be entered
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+ * is one which loses context (eg. SOFF) then this function will never
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+ * return.
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+ */
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+extern int mips_pm_suspend(unsigned state);
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+
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+#else /* !CONFIG_MIPS_MALTA_PM */
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+
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+static inline int mips_pm_suspend(unsigned state)
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+{
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+ return -EINVAL;
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+}
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+
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+#endif /* !CONFIG_MIPS_MALTA_PM */
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+
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+#endif /* __ASM_MIPS_MACH_MALTA_PM_H__ */
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diff --git a/arch/mips/mti-malta/Makefile b/arch/mips/mti-malta/Makefile
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index a851601..b9510ea 100644
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--- a/arch/mips/mti-malta/Makefile
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+++ b/arch/mips/mti-malta/Makefile
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@@ -8,6 +8,8 @@
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obj-y := malta-amon.o malta-display.o malta-init.o \
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malta-int.o malta-memory.o malta-platform.o \
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malta-reset.o malta-setup.o malta-time.o
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+
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+obj-$(CONFIG_MIPS_MALTA_PM) += malta-pm.o
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# FIXME FIXME FIXME
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obj-$(CONFIG_MIPS_MT_SMTC) += malta-smtc.o
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diff --git a/arch/mips/mti-malta/malta-pm.c b/arch/mips/mti-malta/malta-pm.c
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new file mode 100644
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index 0000000..c1e456c
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--- /dev/null
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+++ b/arch/mips/mti-malta/malta-pm.c
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@@ -0,0 +1,96 @@
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+/*
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+ * Copyright (C) 2014 Imagination Technologies
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+ * Author: Paul Burton <paul.burton@imgtec.com>
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+ *
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+ * This program is free software; you can redistribute it and/or modify it
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+ * under the terms of the GNU General Public License as published by the
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+ * Free Software Foundation; either version 2 of the License, or (at your
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+ * option) any later version.
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+ */
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+
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+#include <linux/delay.h>
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+#include <linux/init.h>
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+#include <linux/io.h>
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+#include <linux/pci.h>
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+
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+#include <asm/mach-malta/malta-pm.h>
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+
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+static struct pci_bus *pm_pci_bus;
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+static resource_size_t pm_io_offset;
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+
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+int mips_pm_suspend(unsigned state)
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+{
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+ int spec_devid;
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+ u16 sts;
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+
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+ if (!pm_pci_bus || !pm_io_offset)
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+ return -ENODEV;
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+
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+ /* Ensure the power button status is clear */
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+ while (1) {
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+ sts = inw(pm_io_offset + PIIX4_FUNC3IO_PMSTS);
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+ if (!(sts & PIIX4_FUNC3IO_PMSTS_PWRBTN_STS))
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+ break;
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+ outw(sts, pm_io_offset + PIIX4_FUNC3IO_PMSTS);
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+ }
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+
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+ /* Enable entry to suspend */
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+ outw(state | PIIX4_FUNC3IO_PMCNTRL_SUS_EN,
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+ pm_io_offset + PIIX4_FUNC3IO_PMCNTRL);
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+
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+ /* If the special cycle occurs too soon this doesn't work... */
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+ mdelay(10);
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+
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+ /*
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+ * The PIIX4 will enter the suspend state only after seeing a special
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+ * cycle with the correct magic data on the PCI bus. Generate that
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+ * cycle now.
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+ */
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+ spec_devid = PCI_DEVID(0, PCI_DEVFN(0x1f, 0x7));
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+ pci_bus_write_config_dword(pm_pci_bus, spec_devid, 0,
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+ PIIX4_SUSPEND_MAGIC);
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+
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+ /* Give the system some time to power down */
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+ mdelay(1000);
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+
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+ return 0;
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+}
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+
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+static int __init malta_pm_setup(void)
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+{
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+ struct pci_dev *dev;
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+ int res, io_region = PCI_BRIDGE_RESOURCES;
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+
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+ /* Find a reference to the PCI bus */
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+ pm_pci_bus = pci_find_next_bus(NULL);
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+ if (!pm_pci_bus) {
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+ pr_warn("malta-pm: failed to find reference to PCI bus\n");
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+ return -ENODEV;
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+ }
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+
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+ /* Find the PIIX4 PM device */
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+ dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
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+ PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
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+ PCI_ANY_ID, NULL);
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+ if (!dev) {
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+ pr_warn("malta-pm: failed to find PIIX4 PM\n");
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+ return -ENODEV;
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+ }
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+
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+ /* Request access to the PIIX4 PM IO registers */
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+ res = pci_request_region(dev, io_region, "PIIX4 PM IO registers");
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+ if (res) {
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+ pr_warn("malta-pm: failed to request PM IO registers (%d)\n",
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+ res);
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+ pci_dev_put(dev);
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+ return -ENODEV;
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+ }
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+
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+ /* Find the offset to the PIIX4 PM IO registers */
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+ pm_io_offset = pci_resource_start(dev, io_region);
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+
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+ pci_dev_put(dev);
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+ return 0;
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+}
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+
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+late_initcall(malta_pm_setup);
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--
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2.0.0
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