[PATCH 10/90] ARM: OMAP: Implement workaround for GPIO wakeup bug in OMAP2420 silicon

Tony Lindgren
2007-04-04T18:06:48Z

From: Juha Yrjola <juha.yrjola@solidboot.com>

Some GPIOs on OMAP2420 do not have wakeup capabilities. If these GPIOs
are configured as IRQ sources, spurious interrupts will be generated
each time the core domain enters retention.

Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
arch/arm/plat-omap/gpio.c | 154 +++++++++++++++++++++++++++++++++++++++-----
1 files changed, 136 insertions(+), 18 deletions(-)

diff --git a/arch/arm/plat-omap/gpio.c b/arch/arm/plat-omap/gpio.c
index e2547a7..c6cded5 100644
--- a/arch/arm/plat-omap/gpio.c
+++ b/arch/arm/plat-omap/gpio.c
@@ -118,8 +118,18 @@ struct gpio_bank {
u16 virtual_irq_start;
int method;
u32 reserved_map;
+#if defined (CONFIG_ARCH_OMAP16XX) || defined (CONFIG_ARCH_OMAP24XX)
u32 suspend_wakeup;
u32 saved_wakeup;
+#endif
+#ifdef CONFIG_ARCH_OMAP24XX
+ u32 non_wakeup_gpios;
+ u32 enabled_non_wakeup_gpios;
+
+ u32 saved_datain;
+ u32 saved_fallingdetect;
+ u32 saved_risingdetect;
+#endif
spinlock_t lock;
};

@@ -398,8 +408,10 @@ do { \
__raw_writel(l, base + reg); \
} while(0)

-static inline void set_24xx_gpio_triggering(void __iomem *base, int gpio, int trigger)
+#ifdef CONFIG_ARCH_OMAP24XX
+static inline void set_24xx_gpio_triggering(struct gpio_bank *bank, int gpio, int trigger)
{
+ void __iomem *base = bank->base;
u32 gpio_bit = 1 << gpio;

MOD_REG_BIT(OMAP24XX_GPIO_LEVELDETECT0, gpio_bit,
@@ -410,9 +422,21 @@ static inline void set_24xx_gpio_triggering(void __iomem *base, int gpio, int tr
trigger & __IRQT_RISEDGE);
MOD_REG_BIT(OMAP24XX_GPIO_FALLINGDETECT, gpio_bit,
trigger & __IRQT_FALEDGE);
+ if (likely(!(bank->non_wakeup_gpios & gpio_bit))) {
+ if (trigger != 0)
+ __raw_writel(1 << gpio, bank->base + OMAP24XX_GPIO_SETWKUENA);
+ else
+ __raw_writel(1 << gpio, bank->base + OMAP24XX_GPIO_CLEARWKUENA);
+ } else {
+ if (trigger != 0)
+ bank->enabled_non_wakeup_gpios |= gpio_bit;
+ else
+ bank->enabled_non_wakeup_gpios &= ~gpio_bit;
+ }
/* FIXME: Possibly do 'set_irq_handler(j, handle_level_irq)' if only level
* triggering requested. */
}
+#endif

static int _set_gpio_triggering(struct gpio_bank *bank, int gpio, int trigger)
{
@@ -440,6 +464,7 @@ static int _set_gpio_triggering(struct gpio_bank *bank, int gpio, int trigger)
else
goto bad;
break;
+#ifdef CONFIG_ARCH_OMAP16XX
case METHOD_GPIO_1610:
if (gpio & 0x08)
reg += OMAP1610_GPIO_EDGE_CTRL2;
@@ -455,7 +480,14 @@ static int _set_gpio_triggering(struct gpio_bank *bank, int gpio, int trigger)
l |= 2 << (gpio << 1);
if (trigger & __IRQT_FALEDGE)
l |= 1 << (gpio << 1);
+ if (trigger)
+ /* Enable wake-up during idle for dynamic tick */
+ __raw_writel(1 << gpio, bank->base + OMAP1610_GPIO_SET_WAKEUPENA);
+ else
+ __raw_writel(1 << gpio, bank->base + OMAP1610_GPIO_CLEAR_WAKEUPENA);
break;
+#endif
+#ifdef CONFIG_ARCH_OMAP730
case METHOD_GPIO_730:
reg += OMAP730_GPIO_INT_CONTROL;
l = __raw_readl(reg);
@@ -466,9 +498,12 @@ static int _set_gpio_triggering(struct gpio_bank *bank, int gpio, int trigger)
else
goto bad;
break;
+#endif
+#ifdef CONFIG_ARCH_OMAP24XX
case METHOD_GPIO_24XX:
- set_24xx_gpio_triggering(reg, gpio, trigger);
+ set_24xx_gpio_triggering(bank, gpio, trigger);
break;
+#endif
default:
BUG();
goto bad;
@@ -652,8 +687,8 @@ static inline void _set_gpio_irqenable(struct gpio_bank *bank, int gpio, int ena
static int _set_gpio_wakeup(struct gpio_bank *bank, int gpio, int enable)
{
switch (bank->method) {
+#ifdef CONFIG_ARCH_OMAP16XX
case METHOD_GPIO_1610:
- case METHOD_GPIO_24XX:
spin_lock(&bank->lock);
if (enable)
bank->suspend_wakeup |= (1 << gpio);
@@ -661,6 +696,24 @@ static int _set_gpio_wakeup(struct gpio_bank *bank, int gpio, int enable)
bank->suspend_wakeup &= ~(1 << gpio);
spin_unlock(&bank->lock);
return 0;
+#endif
+#ifdef CONFIG_ARCH_OMAP24XX
+ case METHOD_GPIO_24XX:
+ spin_lock(&bank->lock);
+ if (enable) {
+ if (bank->non_wakeup_gpios & (1 << gpio)) {
+ printk(KERN_ERR "Unable to enable wakeup on"
+ "non-wakeup GPIO%d\n",
+ (bank - gpio_bank) * 32 + gpio);
+ spin_unlock(&bank->lock);
+ return -EINVAL;
+ }
+ bank->suspend_wakeup |= (1 << gpio);
+ } else
+ bank->suspend_wakeup &= ~(1 << gpio);
+ spin_unlock(&bank->lock);
+ return 0;
+#endif
default:
printk(KERN_ERR "Can't enable GPIO wakeup for method %i\n",
bank->method);
@@ -722,20 +775,6 @@ int omap_request_gpio(int gpio)
__raw_writel(__raw_readl(reg) | (1 << get_gpio_index(gpio)), reg);
}
#endif
-#ifdef CONFIG_ARCH_OMAP16XX
- if (bank->method == METHOD_GPIO_1610) {
- /* Enable wake-up during idle for dynamic tick */
- void __iomem *reg = bank->base + OMAP1610_GPIO_SET_WAKEUPENA;
- __raw_writel(1 << get_gpio_index(gpio), reg);
- }
-#endif
-#ifdef CONFIG_ARCH_OMAP24XX
- if (bank->method == METHOD_GPIO_24XX) {
- /* Enable wake-up during idle for dynamic tick */
- void __iomem *reg = bank->base + OMAP24XX_GPIO_SETWKUENA;
- __raw_writel(1 << get_gpio_index(gpio), reg);
- }
-#endif
spin_unlock(&bank->lock);

return 0;
@@ -1081,13 +1120,18 @@ static int __init _omap_gpio_init(void)
#endif
#ifdef CONFIG_ARCH_OMAP24XX
if (bank->method == METHOD_GPIO_24XX) {
+ static const u32 non_wakeup_gpios[] = {
+ 0xe203ffc0, 0x08700040
+ };
+
__raw_writel(0x00000000, bank->base + OMAP24XX_GPIO_IRQENABLE1);
__raw_writel(0xffffffff, bank->base + OMAP24XX_GPIO_IRQSTATUS1);
__raw_writew(0x0015, bank->base + OMAP24XX_GPIO_SYSCONFIG);

/* Initialize interface clock ungated, module enabled */
__raw_writel(0, bank->base + OMAP24XX_GPIO_CTRL);
-
+ if (i < ARRAY_SIZE(non_wakeup_gpios))
+ bank->non_wakeup_gpios = non_wakeup_gpios[i];
gpio_count = 32;
}
#endif
@@ -1201,6 +1245,80 @@ static struct sys_device omap_gpio_device = {
.id = 0,
.cls = &omap_gpio_sysclass,
};
+
+#endif
+
+#ifdef CONFIG_ARCH_OMAP24XX
+
+static int workaround_enabled;
+
+void omap2_gpio_prepare_for_retention(void)
+{
+ int i, c = 0;
+
+ /* Remove triggering for all non-wakeup GPIOs. Otherwise spurious
+ * IRQs will be generated. See OMAP2420 Errata item 1.101. */
+ for (i = 0; i < gpio_bank_count; i++) {
+ struct gpio_bank *bank = &gpio_bank[i];
+ u32 l1, l2;
+
+ if (!(bank->enabled_non_wakeup_gpios))
+ continue;
+ bank->saved_datain = __raw_readl(bank->base + OMAP24XX_GPIO_DATAIN);
+ l1 = __raw_readl(bank->base + OMAP24XX_GPIO_FALLINGDETECT);
+ l2 = __raw_readl(bank->base + OMAP24XX_GPIO_RISINGDETECT);
+ bank->saved_fallingdetect = l1;
+ bank->saved_risingdetect = l2;
+ l1 &= ~bank->enabled_non_wakeup_gpios;
+ l2 &= ~bank->enabled_non_wakeup_gpios;
+ __raw_writel(l1, bank->base + OMAP24XX_GPIO_FALLINGDETECT);
+ __raw_writel(l2, bank->base + OMAP24XX_GPIO_RISINGDETECT);
+ c++;
+ }
+ if (!c) {
+ workaround_enabled = 0;
+ return;
+ }
+ workaround_enabled = 1;
+}
+
+void omap2_gpio_resume_after_retention(void)
+{
+ int i;
+
+ if (!workaround_enabled)
+ return;
+ for (i = 0; i < gpio_bank_count; i++) {
+ struct gpio_bank *bank = &gpio_bank[i];
+ u32 l;
+
+ if (!(bank->enabled_non_wakeup_gpios))
+ continue;
+ __raw_writel(bank->saved_fallingdetect,
+ bank->base + OMAP24XX_GPIO_FALLINGDETECT);
+ __raw_writel(bank->saved_risingdetect,
+ bank->base + OMAP24XX_GPIO_RISINGDETECT);
+ /* Check if any of the non-wakeup interrupt GPIOs have changed
+ * state. If so, generate an IRQ by software. This is
+ * horribly racy, but it's the best we can do to work around
+ * this silicon bug. */
+ l = __raw_readl(bank->base + OMAP24XX_GPIO_DATAIN);
+ l ^= bank->saved_datain;
+ l &= bank->non_wakeup_gpios;
+ if (l) {
+ u32 old0, old1;
+
+ old0 = __raw_readl(bank->base + OMAP24XX_GPIO_LEVELDETECT0);
+ old1 = __raw_readl(bank->base + OMAP24XX_GPIO_LEVELDETECT1);
+ __raw_writel(old0 | l, bank->base + OMAP24XX_GPIO_LEVELDETECT0);
+ __raw_writel(old1 | l, bank->base + OMAP24XX_GPIO_LEVELDETECT1);
+ __raw_writel(old0, bank->base + OMAP24XX_GPIO_LEVELDETECT0);
+ __raw_writel(old1, bank->base + OMAP24XX_GPIO_LEVELDETECT1);
+ }
+ }
+
+}
+
#endif

/*
--
1.4.4.2