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Subject[tip:x86/olpc] x86, olpc-xo1-sci: Add GPE handler and ebook switch functionality
Commit-ID:  7bc74b3df73776fe06f3df9fafd2d2698e6ca28a
Gitweb: http://git.kernel.org/tip/7bc74b3df73776fe06f3df9fafd2d2698e6ca28a
Author: Daniel Drake <dsd@laptop.org>
AuthorDate: Sat, 25 Jun 2011 17:34:14 +0100
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Wed, 6 Jul 2011 14:44:38 -0700

x86, olpc-xo1-sci: Add GPE handler and ebook switch functionality

The EC in the OLPC XO-1 delivers GPE events to provide various
notifications. Add the basic code for GPE/EC event processing and
enable the ebook switch, which can be used as a wakeup source.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Link: http://lkml.kernel.org/r/1309019658-1712-8-git-send-email-dsd@laptop.org
Acked-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/Kconfig | 2 +
arch/x86/include/asm/olpc.h | 5 +-
arch/x86/platform/olpc/olpc-xo1-sci.c | 183 ++++++++++++++++++++++++++++++++-
include/linux/cs5535.h | 22 ++++
4 files changed, 209 insertions(+), 3 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 66b7b9d..8888910 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2087,7 +2087,9 @@ config OLPC_XO1_SCI
select MFD_CORE
---help---
Add support for SCI-based features of the OLPC XO-1 laptop:
+ - EC-driven system wakeups
- Power button
+ - Ebook switch

endif # X86_32

diff --git a/arch/x86/include/asm/olpc.h b/arch/x86/include/asm/olpc.h
index 0e56d01..87bdbca 100644
--- a/arch/x86/include/asm/olpc.h
+++ b/arch/x86/include/asm/olpc.h
@@ -111,6 +111,7 @@ extern int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
#define EC_WRITE_SCI_MASK 0x1b
#define EC_WAKE_UP_WLAN 0x24
#define EC_WLAN_LEAVE_RESET 0x25
+#define EC_READ_EB_MODE 0x2a
#define EC_SET_SCI_INHIBIT 0x32
#define EC_SET_SCI_INHIBIT_RELEASE 0x34
#define EC_WLAN_ENTER_RESET 0x35
@@ -144,7 +145,7 @@ extern int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
#define OLPC_GPIO_SMB_CLK 14
#define OLPC_GPIO_SMB_DATA 15
#define OLPC_GPIO_WORKAUX geode_gpio(24)
-#define OLPC_GPIO_LID geode_gpio(26)
-#define OLPC_GPIO_ECSCI geode_gpio(27)
+#define OLPC_GPIO_LID 26
+#define OLPC_GPIO_ECSCI 27

#endif /* _ASM_X86_OLPC_H */
diff --git a/arch/x86/platform/olpc/olpc-xo1-sci.c b/arch/x86/platform/olpc/olpc-xo1-sci.c
index 8fbf961..63f5050 100644
--- a/arch/x86/platform/olpc/olpc-xo1-sci.c
+++ b/arch/x86/platform/olpc/olpc-xo1-sci.c
@@ -12,12 +12,15 @@
*/

#include <linux/cs5535.h>
+#include <linux/device.h>
+#include <linux/gpio.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 <linux/workqueue.h>

#include <asm/io.h>
#include <asm/msr.h>
@@ -28,8 +31,60 @@

static unsigned long acpi_base;
static struct input_dev *power_button_idev;
+static struct input_dev *ebook_switch_idev;
+
static int sci_irq;

+/* Report current ebook switch state through input layer */
+static void send_ebook_state(void)
+{
+ unsigned char state;
+
+ if (olpc_ec_cmd(EC_READ_EB_MODE, NULL, 0, &state, 1)) {
+ pr_err(PFX "failed to get ebook state\n");
+ return;
+ }
+
+ input_report_switch(ebook_switch_idev, SW_TABLET_MODE, state);
+ input_sync(ebook_switch_idev);
+}
+
+/*
+ * Process all items in the EC's SCI queue.
+ *
+ * This is handled in a workqueue because olpc_ec_cmd can be slow (and
+ * can even timeout).
+ *
+ * If propagate_events is false, the queue is drained without events being
+ * generated for the interrupts.
+ */
+static void process_sci_queue(bool propagate_events)
+{
+ int r;
+ u16 data;
+
+ do {
+ r = olpc_ec_sci_query(&data);
+ if (r || !data)
+ break;
+
+ pr_debug(PFX "SCI 0x%x received\n", data);
+
+ if (data == EC_SCI_SRC_EBOOK && propagate_events)
+ send_ebook_state();
+ } while (data);
+
+ if (r)
+ pr_err(PFX "Failed to clear SCI queue");
+}
+
+static void process_sci_queue_work(struct work_struct *work)
+{
+ process_sci_queue(true);
+}
+
+static DECLARE_WORK(sci_work, process_sci_queue_work);
+
static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
{
struct platform_device *pdev = dev_id;
@@ -51,6 +106,11 @@ static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
input_sync(power_button_idev);
}

+ if (gpe & CS5536_GPIOM7_PME_FLAG) { /* EC GPIO */
+ cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
+ schedule_work(&sci_work);
+ }
+
return IRQ_HANDLED;
}

@@ -60,6 +120,19 @@ static int xo1_sci_suspend(struct platform_device *pdev, pm_message_t state)
olpc_xo1_pm_wakeup_set(CS5536_PM_PWRBTN);
else
olpc_xo1_pm_wakeup_clear(CS5536_PM_PWRBTN);
+
+ if (device_may_wakeup(&ebook_switch_idev->dev))
+ olpc_ec_wakeup_set(EC_SCI_SRC_EBOOK);
+ else
+ olpc_ec_wakeup_clear(EC_SCI_SRC_EBOOK);
+
+ return 0;
+}
+
+static int xo1_sci_resume(struct platform_device *pdev)
+{
+ /* Enable all EC events */
+ olpc_ec_mask_write(EC_SCI_SRC_ALL);
return 0;
}

@@ -104,6 +177,50 @@ static int __devinit setup_sci_interrupt(struct platform_device *pdev)
return r;
}

+static int __devinit setup_ec_sci(void)
+{
+ int r;
+
+ r = gpio_request(OLPC_GPIO_ECSCI, "OLPC-ECSCI");
+ if (r)
+ return r;
+
+ gpio_direction_input(OLPC_GPIO_ECSCI);
+
+ /* Clear pending EC SCI events */
+ cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
+ cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_POSITIVE_EDGE_STS);
+
+ /*
+ * Enable EC SCI events, and map them to both a PME and the SCI
+ * interrupt.
+ *
+ * Ordinarily, in addition to functioning as GPIOs, Geode GPIOs can
+ * be mapped to regular interrupts *or* Geode-specific Power
+ * Management Events (PMEs) - events that bring the system out of
+ * suspend. In this case, we want both of those things - the system
+ * wakeup, *and* the ability to get an interrupt when an event occurs.
+ *
+ * To achieve this, we map the GPIO to a PME, and then we use one
+ * of the many generic knobs on the CS5535 PIC to additionally map the
+ * PME to the regular SCI interrupt line.
+ */
+ cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_EVENTS_ENABLE);
+
+ /* Set the SCI to cause a PME event on group 7 */
+ cs5535_gpio_setup_event(OLPC_GPIO_ECSCI, 7, 1);
+
+ /* And have group 7 also fire the SCI interrupt */
+ cs5535_pic_unreqz_select_high(7, sci_irq);
+
+ return 0;
+}
+
+static void free_ec_sci(void)
+{
+ gpio_free(OLPC_GPIO_ECSCI);
+}
+
static int __devinit setup_power_button(struct platform_device *pdev)
{
int r;
@@ -135,6 +252,37 @@ static void free_power_button(void)
input_free_device(power_button_idev);
}

+static int __devinit setup_ebook_switch(struct platform_device *pdev)
+{
+ int r;
+
+ ebook_switch_idev = input_allocate_device();
+ if (!ebook_switch_idev)
+ return -ENOMEM;
+
+ ebook_switch_idev->name = "EBook Switch";
+ ebook_switch_idev->phys = DRV_NAME "/input1";
+ set_bit(EV_SW, ebook_switch_idev->evbit);
+ set_bit(SW_TABLET_MODE, ebook_switch_idev->swbit);
+
+ ebook_switch_idev->dev.parent = &pdev->dev;
+ device_set_wakeup_capable(&ebook_switch_idev->dev, true);
+
+ r = input_register_device(ebook_switch_idev);
+ if (r) {
+ dev_err(&pdev->dev, "failed to register ebook switch: %d\n", r);
+ input_free_device(ebook_switch_idev);
+ }
+
+ return r;
+}
+
+static void free_ebook_switch(void)
+{
+ input_unregister_device(ebook_switch_idev);
+ input_free_device(ebook_switch_idev);
+}
+
static int __devinit xo1_sci_probe(struct platform_device *pdev)
{
struct resource *res;
@@ -159,10 +307,39 @@ static int __devinit xo1_sci_probe(struct platform_device *pdev)
if (r)
return r;

+ r = setup_ebook_switch(pdev);
+ if (r)
+ goto err_ebook;
+
+ r = setup_ec_sci();
+ if (r)
+ goto err_ecsci;
+
+ /* Enable PME generation for EC-generated events */
+ outl(CS5536_GPIOM7_PME_EN, acpi_base + CS5536_PM_GPE0_EN);
+
+ /* Clear pending events */
+ outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
+ process_sci_queue(false);
+
+ /* Initial sync */
+ send_ebook_state();
+
r = setup_sci_interrupt(pdev);
if (r)
- free_power_button();
+ goto err_sci;

+ /* Enable all EC events */
+ olpc_ec_mask_write(EC_SCI_SRC_ALL);
+
+ return r;
+
+err_sci:
+ free_ec_sci();
+err_ecsci:
+ free_ebook_switch();
+err_ebook:
+ free_power_button();
return r;
}

@@ -170,6 +347,9 @@ static int __devexit xo1_sci_remove(struct platform_device *pdev)
{
mfd_cell_disable(pdev);
free_irq(sci_irq, pdev);
+ cancel_work_sync(&sci_work);
+ free_ec_sci();
+ free_ebook_switch();
free_power_button();
acpi_base = 0;
return 0;
@@ -182,6 +362,7 @@ static struct platform_driver xo1_sci_driver = {
.probe = xo1_sci_probe,
.remove = __devexit_p(xo1_sci_remove),
.suspend = xo1_sci_suspend,
+ .resume = xo1_sci_resume,
};

static int __init xo1_sci_init(void)
diff --git a/include/linux/cs5535.h b/include/linux/cs5535.h
index 6f78235..d7e9a7f 100644
--- a/include/linux/cs5535.h
+++ b/include/linux/cs5535.h
@@ -11,6 +11,8 @@
#ifndef _CS5535_H
#define _CS5535_H

+#include <asm/msr.h>
+
/* MSRs */
#define MSR_GLIU_P2D_RO0 0x10000029

@@ -43,6 +45,18 @@
#define MSR_GX_GLD_MSR_CONFIG 0xC0002001
#define MSR_GX_MSR_PADSEL 0xC0002011

+static inline int cs5535_pic_unreqz_select_high(unsigned int group,
+ unsigned int irq)
+{
+ uint32_t lo, hi;
+
+ rdmsr(MSR_PIC_ZSEL_HIGH, lo, hi);
+ lo &= ~(0xF << (group * 4));
+ lo |= (irq & 0xF) << (group * 4);
+ wrmsr(MSR_PIC_ZSEL_HIGH, lo, hi);
+ return 0;
+}
+
/* PIC registers */
#define CS5536_PIC_INT_SEL1 0x4d0
#define CS5536_PIC_INT_SEL2 0x4d1
@@ -73,6 +87,7 @@
#define CS5536_PM1_EN 0x02
#define CS5536_PM1_CNT 0x08
#define CS5536_PM_GPE0_STS 0x18
+#define CS5536_PM_GPE0_EN 0x1c

/* CS5536_PM1_STS bits */
#define CS5536_WAK_FLAG (1 << 15)
@@ -81,6 +96,13 @@
/* CS5536_PM1_EN bits */
#define CS5536_PM_PWRBTN (1 << 8)

+/* CS5536_PM_GPE0_STS bits */
+#define CS5536_GPIOM7_PME_FLAG (1 << 31)
+#define CS5536_GPIOM6_PME_FLAG (1 << 30)
+
+/* CS5536_PM_GPE0_EN bits */
+#define CS5536_GPIOM7_PME_EN (1 << 31)
+
/* VSA2 magic values */
#define VSA_VRC_INDEX 0xAC1C
#define VSA_VRC_DATA 0xAC1E

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