x86, olpc: Add XO-1 SCI driver and power button control

The System Control Interrupt is used in the OLPC XO-1 to control various
features of the laptop. Add the driver base and the power button
functionality.

This driver can't be built as a module, because functionality added in
future patches means that some drivers need to know at boot-time whether
SCI-based functionality is available.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Link: http://lkml.kernel.org/r/1309019658-1712-6-git-send-email-dsd@laptop.org
Acked-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

3 files changed, 201 insertions, 0 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f473151ac991..66b7b9d519d5 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2080,6 +2080,15 @@ config OLPC_XO1_PM
         ---help---
           Add support for poweroff and suspend of the OLPC XO-1 laptop.
 
+config OLPC_XO1_SCI
+        bool "OLPC XO-1 SCI extras"
+        depends on OLPC && OLPC_XO1_PM
+        select GPIO_CS5535
+        select MFD_CORE
+        ---help---
+          Add support for SCI-based features of the OLPC XO-1 laptop:
+           - Power button
+
 endif # X86_32
 
 config AMD_NB
diff --git a/arch/x86/platform/olpc/Makefile b/arch/x86/platform/olpc/Makefile
index 1ae7bed89821..1ec5ade97f44 100644
--- a/arch/x86/platform/olpc/Makefile
+++ b/arch/x86/platform/olpc/Makefile
@@ -1,2 +1,3 @@
 obj-$(CONFIG_OLPC)              += olpc.o olpc_ofw.o olpc_dt.o
 obj-$(CONFIG_OLPC_XO1_PM)               += olpc-xo1-pm.o xo1-wakeup.o
+obj-$(CONFIG_OLPC_XO1_SCI)      += olpc-xo1-sci.o
diff --git a/arch/x86/platform/olpc/olpc-xo1-sci.c b/arch/x86/platform/olpc/olpc-xo1-sci.c
new file mode 100644
index 000000000000..8fbf961dae89
--- /dev/null
+++ b/arch/x86/platform/olpc/olpc-xo1-sci.c
@@ -0,0 +1,191 @@
+/*
+ * Support for OLPC XO-1 System Control Interrupts (SCI)
+ *
+ * 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/cs5535.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/mfd/core.h>
+#include <linux/suspend.h>
+
+#include <asm/io.h>
+#include <asm/msr.h>
+#include <asm/olpc.h>
+
+#define DRV_NAME        "olpc-xo1-sci"
+#define PFX             DRV_NAME ": "
+
+static unsigned long acpi_base;
+static struct input_dev *power_button_idev;
+static int sci_irq;
+
+static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
+{
+        struct platform_device *pdev = dev_id;
+        u32 sts;
+        u32 gpe;
+
+        sts = inl(acpi_base + CS5536_PM1_STS);
+        outl(sts | 0xffff, acpi_base + CS5536_PM1_STS);
+
+        gpe = inl(acpi_base + CS5536_PM_GPE0_STS);
+        outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
+
+        dev_dbg(&pdev->dev, "sts %x gpe %x\n", sts, gpe);
+
+        if (sts & CS5536_PWRBTN_FLAG && !(sts & CS5536_WAK_FLAG)) {
+                input_report_key(power_button_idev, KEY_POWER, 1);
+                input_sync(power_button_idev);
+                input_report_key(power_button_idev, KEY_POWER, 0);
+                input_sync(power_button_idev);
+        }
+
+        return IRQ_HANDLED;
+}
+
+static int xo1_sci_suspend(struct platform_device *pdev, pm_message_t state)
+{
+        if (device_may_wakeup(&power_button_idev->dev))
+                olpc_xo1_pm_wakeup_set(CS5536_PM_PWRBTN);
+        else
+                olpc_xo1_pm_wakeup_clear(CS5536_PM_PWRBTN);
+        return 0;
+}
+
+static int __devinit setup_sci_interrupt(struct platform_device *pdev)
+{
+        u32 lo, hi;
+        u32 sts;
+        int r;
+
+        rdmsr(0x51400020, lo, hi);
+        sci_irq = (lo >> 20) & 15;
+
+        if (sci_irq) {
+                dev_info(&pdev->dev, "SCI is mapped to IRQ %d\n", sci_irq);
+        } else {
+                /* Zero means masked */
+                dev_info(&pdev->dev, "SCI unmapped. Mapping to IRQ 3\n");
+                sci_irq = 3;
+                lo |= 0x00300000;
+                wrmsrl(0x51400020, lo);
+        }
+
+        /* Select level triggered in PIC */
+        if (sci_irq < 8) {
+                lo = inb(CS5536_PIC_INT_SEL1);
+                lo |= 1 << sci_irq;
+                outb(lo, CS5536_PIC_INT_SEL1);
+        } else {
+                lo = inb(CS5536_PIC_INT_SEL2);
+                lo |= 1 << (sci_irq - 8);
+                outb(lo, CS5536_PIC_INT_SEL2);
+        }
+
+        /* Enable SCI from power button, and clear pending interrupts */
+        sts = inl(acpi_base + CS5536_PM1_STS);
+        outl((CS5536_PM_PWRBTN << 16) | 0xffff, acpi_base + CS5536_PM1_STS);
+
+        r = request_irq(sci_irq, xo1_sci_intr, 0, DRV_NAME, pdev);
+        if (r)
+                dev_err(&pdev->dev, "can't request interrupt\n");
+
+        return r;
+}
+
+static int __devinit setup_power_button(struct platform_device *pdev)
+{
+        int r;
+
+        power_button_idev = input_allocate_device();
+        if (!power_button_idev)
+                return -ENOMEM;
+
+        power_button_idev->name = "Power Button";
+        power_button_idev->phys = DRV_NAME "/input0";
+        set_bit(EV_KEY, power_button_idev->evbit);
+        set_bit(KEY_POWER, power_button_idev->keybit);
+
+        power_button_idev->dev.parent = &pdev->dev;
+        device_init_wakeup(&power_button_idev->dev, 1);
+
+        r = input_register_device(power_button_idev);
+        if (r) {
+                dev_err(&pdev->dev, "failed to register power button: %d\n", r);
+                input_free_device(power_button_idev);
+        }
+
+        return r;
+}
+
+static void free_power_button(void)
+{
+        input_unregister_device(power_button_idev);
+        input_free_device(power_button_idev);
+}
+
+static int __devinit xo1_sci_probe(struct platform_device *pdev)
+{
+        struct resource *res;
+        int r;
+
+        /* don't run on non-XOs */
+        if (!machine_is_olpc())
+                return -ENODEV;
+
+        r = mfd_cell_enable(pdev);
+        if (r)
+                return r;
+
+        res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+        if (!res) {
+                dev_err(&pdev->dev, "can't fetch device resource info\n");
+                return -EIO;
+        }
+        acpi_base = res->start;
+
+        r = setup_power_button(pdev);
+        if (r)
+                return r;
+
+        r = setup_sci_interrupt(pdev);
+        if (r)
+                free_power_button();
+
+        return r;
+}
+
+static int __devexit xo1_sci_remove(struct platform_device *pdev)
+{
+        mfd_cell_disable(pdev);
+        free_irq(sci_irq, pdev);
+        free_power_button();
+        acpi_base = 0;
+        return 0;
+}
+
+static struct platform_driver xo1_sci_driver = {
+        .driver = {
+                .name = "olpc-xo1-sci-acpi",
+        },
+        .probe = xo1_sci_probe,
+        .remove = __devexit_p(xo1_sci_remove),
+        .suspend = xo1_sci_suspend,
+};
+
+static int __init xo1_sci_init(void)
+{
+        return platform_driver_register(&xo1_sci_driver);
+}
+arch_initcall(xo1_sci_init);