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Subject[PATCH v2 08/11] x86, olpc-xo1-sci: Add lid switch functionality
Date
Configure the XO-1's lid switch GPIO to trigger an SCI interrupt,
and correctly expose this input device which can be used as a wakeup
source.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Acked-by: Andres Salomon <dilinger@queued.net>
---
arch/x86/Kconfig | 1 +
arch/x86/platform/olpc/olpc-xo1-sci.c | 207 ++++++++++++++++++++++++++++++++-
include/linux/cs5535.h | 1 +
3 files changed, 208 insertions(+), 1 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index e2405a4..3494348 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2087,6 +2087,7 @@ config OLPC_XO1_SCI
- EC-driven system wakeups
- Power button
- Ebook switch
+ - Lid switch

endif # X86_32

diff --git a/arch/x86/platform/olpc/olpc-xo1-sci.c b/arch/x86/platform/olpc/olpc-xo1-sci.c
index 63f5050..ad0670b 100644
--- a/arch/x86/platform/olpc/olpc-xo1-sci.c
+++ b/arch/x86/platform/olpc/olpc-xo1-sci.c
@@ -32,9 +32,26 @@
static unsigned long acpi_base;
static struct input_dev *power_button_idev;
static struct input_dev *ebook_switch_idev;
+static struct input_dev *lid_switch_idev;

static int sci_irq;

+static bool lid_open;
+static bool lid_inverted;
+static int lid_wake_mode;
+
+enum lid_wake_modes {
+ LID_WAKE_ALWAYS,
+ LID_WAKE_OPEN,
+ LID_WAKE_CLOSE,
+};
+
+static const char * const lid_wake_mode_names[] = {
+ [LID_WAKE_ALWAYS] = "always",
+ [LID_WAKE_OPEN] = "open",
+ [LID_WAKE_CLOSE] = "close",
+};
+
/* Report current ebook switch state through input layer */
static void send_ebook_state(void)
{
@@ -49,6 +66,70 @@ static void send_ebook_state(void)
input_sync(ebook_switch_idev);
}

+static void flip_lid_inverter(void)
+{
+ /* gpio is high; invert so we'll get l->h event interrupt */
+ if (lid_inverted)
+ cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
+ else
+ cs5535_gpio_set(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
+ lid_inverted = !lid_inverted;
+}
+
+static void detect_lid_state(void)
+{
+ /*
+ * the edge detector hookup on the gpio inputs on the geode is
+ * odd, to say the least. See http://dev.laptop.org/ticket/5703
+ * for details, but in a nutshell: we don't use the edge
+ * detectors. instead, we make use of an anomoly: with the both
+ * edge detectors turned off, we still get an edge event on a
+ * positive edge transition. to take advantage of this, we use the
+ * front-end inverter to ensure that that's the edge we're always
+ * going to see next.
+ */
+
+ int state;
+
+ state = cs5535_gpio_isset(OLPC_GPIO_LID, GPIO_READ_BACK);
+ lid_open = !state ^ !lid_inverted; /* x ^^ y */
+ if (!state)
+ return;
+
+ flip_lid_inverter();
+}
+
+/* Report current lid switch state through input layer */
+static void send_lid_state(void)
+{
+ input_report_switch(lid_switch_idev, SW_LID, !lid_open);
+ input_sync(lid_switch_idev);
+}
+
+static ssize_t lid_wake_mode_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ const char *mode = lid_wake_mode_names[lid_wake_mode];
+ return sprintf(buf, "%s\n", mode);
+}
+static ssize_t lid_wake_mode_set(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int i;
+ for (i = 0; i < ARRAY_SIZE(lid_wake_mode_names); i++) {
+ const char *mode = lid_wake_mode_names[i];
+ if (strlen(mode) != count || strncasecmp(mode, buf, count))
+ continue;
+
+ lid_wake_mode = i;
+ return count;
+ }
+ return -EINVAL;
+}
+static DEVICE_ATTR(lid_wake_mode, S_IWUSR | S_IRUGO, lid_wake_mode_show,
+ lid_wake_mode_set);
+
/*
* Process all items in the EC's SCI queue.
*
@@ -111,6 +192,11 @@ static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
schedule_work(&sci_work);
}

+ cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
+ cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
+ detect_lid_state();
+ send_lid_state();
+
return IRQ_HANDLED;
}

@@ -126,11 +212,32 @@ static int xo1_sci_suspend(struct platform_device *pdev, pm_message_t state)
else
olpc_ec_wakeup_clear(EC_SCI_SRC_EBOOK);

+ if (!device_may_wakeup(&lid_switch_idev->dev)) {
+ cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
+ } else if ((lid_open && lid_wake_mode == LID_WAKE_OPEN) ||
+ (!lid_open && lid_wake_mode == LID_WAKE_CLOSE)) {
+ flip_lid_inverter();
+
+ /* we may have just caused an event */
+ cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
+ cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
+
+ cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
+ }
+
return 0;
}

static int xo1_sci_resume(struct platform_device *pdev)
{
+ /*
+ * We don't know what may have happened while we were asleep.
+ * Reestablish our lid setup so we're sure to catch all transitions.
+ */
+ detect_lid_state();
+ send_lid_state();
+ cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
+
/* Enable all EC events */
olpc_ec_mask_write(EC_SCI_SRC_ALL);
return 0;
@@ -221,6 +328,43 @@ static void free_ec_sci(void)
gpio_free(OLPC_GPIO_ECSCI);
}

+static int __devinit setup_lid_events(void)
+{
+ int r;
+
+ r = gpio_request(OLPC_GPIO_LID, "OLPC-LID");
+ if (r)
+ return r;
+
+ gpio_direction_input(OLPC_GPIO_LID);
+
+ cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
+ lid_inverted = 0;
+
+ /* Clear edge detection and event enable for now */
+ cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
+ cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_EN);
+ cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_EN);
+ cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
+ cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
+
+ /* Set the LID to cause an PME event on group 6 */
+ cs5535_gpio_setup_event(OLPC_GPIO_LID, 6, 1);
+
+ /* Set PME group 6 to fire the SCI interrupt */
+ cs5535_gpio_set_irq(6, sci_irq);
+
+ /* Enable the event */
+ cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
+
+ return 0;
+}
+
+static void free_lid_events(void)
+{
+ gpio_free(OLPC_GPIO_LID);
+}
+
static int __devinit setup_power_button(struct platform_device *pdev)
{
int r;
@@ -283,6 +427,50 @@ static void free_ebook_switch(void)
input_free_device(ebook_switch_idev);
}

+static int __devinit setup_lid_switch(struct platform_device *pdev)
+{
+ int r;
+
+ lid_switch_idev = input_allocate_device();
+ if (!lid_switch_idev)
+ return -ENOMEM;
+
+ lid_switch_idev->name = "Lid Switch";
+ lid_switch_idev->phys = DRV_NAME "/input2";
+ set_bit(EV_SW, lid_switch_idev->evbit);
+ set_bit(SW_LID, lid_switch_idev->swbit);
+
+ lid_switch_idev->dev.parent = &pdev->dev;
+ device_set_wakeup_capable(&lid_switch_idev->dev, true);
+
+ r = input_register_device(lid_switch_idev);
+ if (r) {
+ dev_err(&pdev->dev, "failed to register lid switch: %d\n", r);
+ goto err_register;
+ }
+
+ r = device_create_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
+ if (r) {
+ dev_err(&pdev->dev, "failed to create wake mode attr: %d\n", r);
+ goto err_create_attr;
+ }
+
+ return 0;
+
+err_create_attr:
+ input_unregister_device(lid_switch_idev);
+err_register:
+ input_free_device(lid_switch_idev);
+ return r;
+}
+
+static void free_lid_switch(void)
+{
+ device_remove_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
+ input_unregister_device(lid_switch_idev);
+ input_free_device(lid_switch_idev);
+}
+
static int __devinit xo1_sci_probe(struct platform_device *pdev)
{
struct resource *res;
@@ -311,12 +499,21 @@ static int __devinit xo1_sci_probe(struct platform_device *pdev)
if (r)
goto err_ebook;

+ r = setup_lid_switch(pdev);
+ if (r)
+ goto err_lid;
+
+ r = setup_lid_events();
+ if (r)
+ goto err_lidevt;
+
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);
+ outl(CS5536_GPIOM6_PME_EN | CS5536_GPIOM7_PME_EN,
+ acpi_base + CS5536_PM_GPE0_EN);

/* Clear pending events */
outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
@@ -324,6 +521,8 @@ static int __devinit xo1_sci_probe(struct platform_device *pdev)

/* Initial sync */
send_ebook_state();
+ detect_lid_state();
+ send_lid_state();

r = setup_sci_interrupt(pdev);
if (r)
@@ -337,6 +536,10 @@ static int __devinit xo1_sci_probe(struct platform_device *pdev)
err_sci:
free_ec_sci();
err_ecsci:
+ free_lid_events();
+err_lidevt:
+ free_lid_switch();
+err_lid:
free_ebook_switch();
err_ebook:
free_power_button();
@@ -349,6 +552,8 @@ static int __devexit xo1_sci_remove(struct platform_device *pdev)
free_irq(sci_irq, pdev);
cancel_work_sync(&sci_work);
free_ec_sci();
+ free_lid_events();
+ free_lid_switch();
free_ebook_switch();
free_power_button();
acpi_base = 0;
diff --git a/include/linux/cs5535.h b/include/linux/cs5535.h
index d7e9a7f..72954c6 100644
--- a/include/linux/cs5535.h
+++ b/include/linux/cs5535.h
@@ -102,6 +102,7 @@ static inline int cs5535_pic_unreqz_select_high(unsigned int group,

/* CS5536_PM_GPE0_EN bits */
#define CS5536_GPIOM7_PME_EN (1 << 31)
+#define CS5536_GPIOM6_PME_EN (1 << 30)

/* VSA2 magic values */
#define VSA_VRC_INDEX 0xAC1C
--
1.7.5.2


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