[PATCH 05/11] x86, olpc: Add XO-1 SCI driver and power button control

From: Daniel Drake
Date: Sat Apr 30 2011 - 08:54:20 EST


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@xxxxxxxxxx>
---
arch/x86/Kconfig | 7 ++
arch/x86/platform/olpc/Makefile | 1 +
arch/x86/platform/olpc/olpc-xo1-sci.c | 191 +++++++++++++++++++++++++++++++++
include/linux/cs5535.h | 8 ++
4 files changed, 207 insertions(+), 0 deletions(-)
create mode 100644 arch/x86/platform/olpc/olpc-xo1-sci.c

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ec9cf25..c273c62 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2072,6 +2072,13 @@ 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
+ ---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 1ae7bed..1ec5ade 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 0000000..8fbf961
--- /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);
diff --git a/include/linux/cs5535.h b/include/linux/cs5535.h
index 2facf16..6f78235 100644
--- a/include/linux/cs5535.h
+++ b/include/linux/cs5535.h
@@ -43,6 +43,10 @@
#define MSR_GX_GLD_MSR_CONFIG 0xC0002001
#define MSR_GX_MSR_PADSEL 0xC0002011

+/* PIC registers */
+#define CS5536_PIC_INT_SEL1 0x4d0
+#define CS5536_PIC_INT_SEL2 0x4d1
+
/* resource sizes */
#define LBAR_GPIO_SIZE 0xFF
#define LBAR_MFGPT_SIZE 0x40
@@ -70,6 +74,10 @@
#define CS5536_PM1_CNT 0x08
#define CS5536_PM_GPE0_STS 0x18

+/* CS5536_PM1_STS bits */
+#define CS5536_WAK_FLAG (1 << 15)
+#define CS5536_PWRBTN_FLAG (1 << 8)
+
/* CS5536_PM1_EN bits */
#define CS5536_PM_PWRBTN (1 << 8)

--
1.7.4.4

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