From mboxrd@z Thu Jan 1 00:00:00 1970 From: riyer@nvidia.com Subject: [PATCH v1] Input: tegra-kbc - fix wakeup from suspend. Date: Thu, 25 Aug 2011 17:29:47 -0700 Message-ID: <1314318587-31348-1-git-send-email-riyer@nvidia.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: dmitry.torokhov@gmail.com Cc: rydberg@euromail.se, axel.lin@gmail.com, olof@lixom.net, amartin@nvidia.com, linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, Rakesh Iyer List-Id: linux-input@vger.kernel.org From: Rakesh Iyer 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 --- 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