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Date: Thu, 25 Aug 2011 17:29:47 -0700
From: riyer@...dia.com
To: dmitry.torokhov@...il.com
Cc: rydberg@...omail.se, axel.lin@...il.com, olof@...om.net,
amartin@...dia.com, linux-kernel@...r.kernel.org,
linux-input@...r.kernel.org, Rakesh Iyer <riyer@...dia.com>
Subject: [PATCH v1] Input: tegra-kbc - fix wakeup from suspend.
From: Rakesh Iyer <riyer@...dia.com>
For wakeup to be reliable, kbc needs to be in interrupt mode before suspend.
Created common routine to control the FIFO interrupt.
Added synchronization to ensure orderly suspend.
Signed-off-by: Rakesh Iyer <riyer@...dia.com>
---
drivers/input/keyboard/tegra-kbc.c | 83 +++++++++++++++++++++++++++++-------
1 files changed, 67 insertions(+), 16 deletions(-)
diff --git a/drivers/input/keyboard/tegra-kbc.c b/drivers/input/keyboard/tegra-kbc.c
index a5a7791..41de11f 100644
--- a/drivers/input/keyboard/tegra-kbc.c
+++ b/drivers/input/keyboard/tegra-kbc.c
@@ -38,7 +38,7 @@
#define KBC_ROW_SCAN_DLY 5
/* KBC uses a 32KHz clock so a cycle = 1/32Khz */
-#define KBC_CYCLE_MS 32
+#define KBC_CYCLES_PER_MS 32
/* KBC Registers */
@@ -55,6 +55,7 @@
#define KBC_ROW_CFG0_0 0x8
#define KBC_COL_CFG0_0 0x18
+#define KBC_TO_CNT_0 0x24
#define KBC_INIT_DLY_0 0x28
#define KBC_RPT_DLY_0 0x2c
#define KBC_KP_ENT0_0 0x30
@@ -70,8 +71,10 @@ struct tegra_kbc {
spinlock_t lock;
unsigned int repoll_dly;
unsigned long cp_dly_jiffies;
+ unsigned int cp_to_wkup_dly;
bool use_fn_map;
bool use_ghost_filter;
+ bool in_suspend;
const struct tegra_kbc_platform_data *pdata;
unsigned short keycode[KBC_MAX_KEY * 2];
unsigned short current_keys[KBC_MAX_KPENT];
@@ -341,6 +344,18 @@ static void tegra_kbc_report_keys(struct tegra_kbc *kbc)
kbc->num_pressed_keys = num_down;
}
+static void tegra_kbc_set_fifo_interrupt(struct tegra_kbc *kbc, bool enable)
+{
+ u32 val;
+
+ val = readl(kbc->mmio + KBC_CONTROL_0);
+ if (enable)
+ val |= KBC_CONTROL_FIFO_CNT_INT_EN;
+ else
+ val &= ~KBC_CONTROL_FIFO_CNT_INT_EN;
+ writel(val, kbc->mmio + KBC_CONTROL_0);
+}
+
static void tegra_kbc_keypress_timer(unsigned long data)
{
struct tegra_kbc *kbc = (struct tegra_kbc *)data;
@@ -348,6 +363,14 @@ static void tegra_kbc_keypress_timer(unsigned long data)
u32 val;
unsigned int i;
+ /* Exit immediately if driver is trying to enter suspend. */
+ spin_lock_irqsave(&kbc->lock, flags);
+ if (kbc->in_suspend) {
+ tegra_kbc_set_fifo_interrupt(kbc, true);
+ spin_unlock_irqrestore(&kbc->lock, flags);
+ return;
+ }
+ spin_unlock_irqrestore(&kbc->lock, flags);
val = (readl(kbc->mmio + KBC_INT_0) >> 4) & 0xf;
if (val) {
unsigned long dly;
@@ -370,9 +393,7 @@ static void tegra_kbc_keypress_timer(unsigned long data)
/* All keys are released so enable the keypress interrupt */
spin_lock_irqsave(&kbc->lock, flags);
- val = readl(kbc->mmio + KBC_CONTROL_0);
- val |= KBC_CONTROL_FIFO_CNT_INT_EN;
- writel(val, kbc->mmio + KBC_CONTROL_0);
+ tegra_kbc_set_fifo_interrupt(kbc, true);
spin_unlock_irqrestore(&kbc->lock, flags);
}
}
@@ -380,15 +401,14 @@ static void tegra_kbc_keypress_timer(unsigned long data)
static irqreturn_t tegra_kbc_isr(int irq, void *args)
{
struct tegra_kbc *kbc = args;
- u32 val, ctl;
+ unsigned long flags;
+ u32 val;
/*
* Until all keys are released, defer further processing to
* the polling loop in tegra_kbc_keypress_timer
*/
- ctl = readl(kbc->mmio + KBC_CONTROL_0);
- ctl &= ~KBC_CONTROL_FIFO_CNT_INT_EN;
- writel(ctl, kbc->mmio + KBC_CONTROL_0);
+ tegra_kbc_set_fifo_interrupt(kbc, false);
/*
* Quickly bail out & reenable interrupts if the fifo threshold
@@ -397,16 +417,18 @@ static irqreturn_t tegra_kbc_isr(int irq, void *args)
val = readl(kbc->mmio + KBC_INT_0);
writel(val, kbc->mmio + KBC_INT_0);
- if (val & KBC_INT_FIFO_CNT_INT_STATUS) {
+ /* Exit immediately if driver is trying to enter suspend. */
+ spin_lock_irqsave(&kbc->lock, flags);
+ if (!kbc->in_suspend && (val & KBC_INT_FIFO_CNT_INT_STATUS))
/*
* Schedule timer to run when hardware is in continuous
* polling mode.
*/
mod_timer(&kbc->timer, jiffies + kbc->cp_dly_jiffies);
- } else {
- ctl |= KBC_CONTROL_FIFO_CNT_INT_EN;
- writel(ctl, kbc->mmio + KBC_CONTROL_0);
- }
+ else
+ tegra_kbc_set_fifo_interrupt(kbc, true);
+
+ spin_unlock_irqrestore(&kbc->lock, flags);
return IRQ_HANDLED;
}
@@ -648,7 +670,7 @@ static int __devinit tegra_kbc_probe(struct platform_device *pdev)
debounce_cnt = min(pdata->debounce_cnt, KBC_MAX_DEBOUNCE_CNT);
scan_time_rows = (KBC_ROW_SCAN_TIME + debounce_cnt) * num_rows;
kbc->repoll_dly = KBC_ROW_SCAN_DLY + scan_time_rows + pdata->repeat_cnt;
- kbc->repoll_dly = DIV_ROUND_UP(kbc->repoll_dly, KBC_CYCLE_MS);
+ kbc->repoll_dly = DIV_ROUND_UP(kbc->repoll_dly, KBC_CYCLES_PER_MS);
input_dev->name = pdev->name;
input_dev->id.bustype = BUS_HOST;
@@ -735,10 +757,29 @@ static int tegra_kbc_suspend(struct device *dev)
struct tegra_kbc *kbc = platform_get_drvdata(pdev);
if (device_may_wakeup(&pdev->dev)) {
- tegra_kbc_setup_wakekeys(kbc, true);
- enable_irq_wake(kbc->irq);
+ unsigned long flags;
+
+ spin_lock_irqsave(&kbc->lock, flags);
+ kbc->in_suspend = 1;
+ spin_unlock_irqrestore(&kbc->lock, flags);
+
+ del_timer(&kbc->timer);
+
+ spin_lock_irqsave(&kbc->lock, flags);
+ tegra_kbc_set_fifo_interrupt(kbc, false);
+ spin_unlock_irqrestore(&kbc->lock, flags);
+
/* Forcefully clear the interrupt status */
writel(0x7, kbc->mmio + KBC_INT_0);
+ /*
+ * Store the previous resident time of continuous polling mode.
+ * Force the keyboard into interrupt mode.
+ */
+ kbc->cp_to_wkup_dly = readl(kbc->mmio + KBC_TO_CNT_0);
+ writel(0, kbc->mmio + KBC_TO_CNT_0);
+
+ tegra_kbc_setup_wakekeys(kbc, true);
+ enable_irq_wake(kbc->irq);
msleep(30);
} else {
mutex_lock(&kbc->idev->mutex);
@@ -757,8 +798,18 @@ static int tegra_kbc_resume(struct device *dev)
int err = 0;
if (device_may_wakeup(&pdev->dev)) {
+ unsigned long flags;
+
disable_irq_wake(kbc->irq);
tegra_kbc_setup_wakekeys(kbc, false);
+
+ /* Restore the resident time of continuous polling mode. */
+ writel(kbc->cp_to_wkup_dly, kbc->mmio + KBC_TO_CNT_0);
+ kbc->in_suspend = 0;
+
+ spin_lock_irqsave(&kbc->lock, flags);
+ tegra_kbc_set_fifo_interrupt(kbc, true);
+ spin_unlock_irqrestore(&kbc->lock, flags);
} else {
mutex_lock(&kbc->idev->mutex);
if (kbc->idev->users)
--
1.7.1
--
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