x86, olpc: Add XO-1 poweroff support

Add a pm_power_off handler for the OLPC XO-1 laptop.

The driver can be built modular and follows the behaviour of the
APM driver, setting pm_power_off to NULL on unload. However, the
ability to unload the module will probably be removed (with a simple
__module_get(THIS_MODULE)) if/when XO-1 suspend/resume support is
added to this file at a later date.

Signed-off-by: Daniel Drake <dsd@laptop.org>
LKML-Reference: <20101010094032.9AE669D401B@zog.reactivated.net>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

3 files changed, 147 insertions, 0 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index c25525571347..0bcb8765b1c0 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2066,6 +2066,12 @@ config OLPC
           Add support for detecting the unique features of the OLPC
           XO hardware.
 
+config OLPC_XO1
+        tristate "OLPC XO-1 support"
+        depends on OLPC
+        ---help---
+          Add support for non-essential features of the OLPC XO-1 laptop.
+
 config OLPC_OPENFIRMWARE
         bool "Support for OLPC's Open Firmware"
         depends on !X86_64 && !X86_PAE
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 0925676266bd..e9777791e39c 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -104,6 +104,7 @@ obj-$(CONFIG_SCx200)		+= scx200.o
 scx200-y                        += scx200_32.o
 
 obj-$(CONFIG_OLPC)              += olpc.o
+obj-$(CONFIG_OLPC_XO1)          += olpc-xo1.o
 obj-$(CONFIG_OLPC_OPENFIRMWARE) += olpc_ofw.o
 obj-$(CONFIG_X86_MRST)          += mrst.o
 
diff --git a/arch/x86/kernel/olpc-xo1.c b/arch/x86/kernel/olpc-xo1.c
new file mode 100644
index 000000000000..f5442c03abc3
--- /dev/null
+++ b/arch/x86/kernel/olpc-xo1.c
@@ -0,0 +1,140 @@
+/*
+ * Support for features of the OLPC XO-1 laptop
+ *
+ * Copyright (C) 2010 One Laptop per Child
+ * Copyright (C) 2006 Red Hat, Inc.
+ * Copyright (C) 2006 Advanced Micro Devices, Inc.
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+
+#include <asm/io.h>
+#include <asm/olpc.h>
+
+#define DRV_NAME "olpc-xo1"
+
+#define PMS_BAR         4
+#define ACPI_BAR        5
+
+/* PMC registers (PMS block) */
+#define PM_SCLK         0x10
+#define PM_IN_SLPCTL    0x20
+#define PM_WKXD         0x34
+#define PM_WKD          0x30
+#define PM_SSC          0x54
+
+/* PM registers (ACPI block) */
+#define PM1_CNT         0x08
+#define PM_GPE0_STS     0x18
+
+static unsigned long acpi_base;
+static unsigned long pms_base;
+
+static void xo1_power_off(void)
+{
+        printk(KERN_INFO "OLPC XO-1 power off sequence...\n");
+
+        /* Enable all of these controls with 0 delay */
+        outl(0x40000000, pms_base + PM_SCLK);
+        outl(0x40000000, pms_base + PM_IN_SLPCTL);
+        outl(0x40000000, pms_base + PM_WKXD);
+        outl(0x40000000, pms_base + PM_WKD);
+
+        /* Clear status bits (possibly unnecessary) */
+        outl(0x0002ffff, pms_base  + PM_SSC);
+        outl(0xffffffff, acpi_base + PM_GPE0_STS);
+
+        /* Write SLP_EN bit to start the machinery */
+        outl(0x00002000, acpi_base + PM1_CNT);
+}
+
+/* Read the base addresses from the PCI BAR info */
+static int __devinit setup_bases(struct pci_dev *pdev)
+{
+        int r;
+
+        r = pci_enable_device_io(pdev);
+        if (r) {
+                dev_err(&pdev->dev, "can't enable device IO\n");
+                return r;
+        }
+
+        r = pci_request_region(pdev, ACPI_BAR, DRV_NAME);
+        if (r) {
+                dev_err(&pdev->dev, "can't alloc PCI BAR #%d\n", ACPI_BAR);
+                return r;
+        }
+
+        r = pci_request_region(pdev, PMS_BAR, DRV_NAME);
+        if (r) {
+                dev_err(&pdev->dev, "can't alloc PCI BAR #%d\n", PMS_BAR);
+                pci_release_region(pdev, ACPI_BAR);
+                return r;
+        }
+
+        acpi_base = pci_resource_start(pdev, ACPI_BAR);
+        pms_base = pci_resource_start(pdev, PMS_BAR);
+
+        return 0;
+}
+
+static int __devinit olpc_xo1_probe(struct platform_device *pdev)
+{
+        struct pci_dev *pcidev;
+        int r;
+
+        pcidev = pci_get_device(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA,
+                                NULL);
+        if (!pdev)
+                return -ENODEV;
+
+        r = setup_bases(pcidev);
+        if (r)
+                return r;
+
+        pm_power_off = xo1_power_off;
+
+        printk(KERN_INFO "OLPC XO-1 support registered\n");
+        return 0;
+}
+
+static int __devexit olpc_xo1_remove(struct platform_device *pdev)
+{
+        pm_power_off = NULL;
+        return 0;
+}
+
+static struct platform_driver olpc_xo1_driver = {
+        .driver = {
+                .name = DRV_NAME,
+                .owner = THIS_MODULE,
+        },
+        .probe = olpc_xo1_probe,
+        .remove = __devexit_p(olpc_xo1_remove),
+};
+
+static int __init olpc_xo1_init(void)
+{
+        return platform_driver_register(&olpc_xo1_driver);
+}
+
+static void __exit olpc_xo1_exit(void)
+{
+        platform_driver_unregister(&olpc_xo1_driver);
+}
+
+MODULE_AUTHOR("Daniel Drake <dsd@laptop.org>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:olpc-xo1");
+
+module_init(olpc_xo1_init);
+module_exit(olpc_xo1_exit);