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-rw-r--r--arch/arm/plat-nomadik/gpio.c211
-rw-r--r--arch/arm/plat-nomadik/include/plat/gpio.h1
2 files changed, 172 insertions, 40 deletions
diff --git a/arch/arm/plat-nomadik/gpio.c b/arch/arm/plat-nomadik/gpio.c
index bf299cf3459..9f1b7205627 100644
--- a/arch/arm/plat-nomadik/gpio.c
+++ b/arch/arm/plat-nomadik/gpio.c
@@ -47,6 +47,8 @@ static const u32 backup_regs[] = {
NMK_GPIO_FWIMSC,
};
+#define NMK_GPIO_PER_CHIP 32
+
struct nmk_gpio_chip {
struct gpio_chip chip;
void __iomem *addr;
@@ -55,6 +57,7 @@ struct nmk_gpio_chip {
unsigned int parent_irq;
int secondary_parent_irq;
u32 (*get_secondary_status)(unsigned int bank);
+ void (*set_ioforce)(bool enable);
spinlock_t lock;
/* Keep track of configured edges */
u32 edge_rising;
@@ -64,6 +67,13 @@ struct nmk_gpio_chip {
u32 pull;
};
+static struct nmk_gpio_chip *
+nmk_gpio_chips[DIV_ROUND_UP(ARCH_NR_GPIOS, NMK_GPIO_PER_CHIP)];
+
+static DEFINE_SPINLOCK(nmk_gpio_slpm_lock);
+
+#define NUM_BANKS ARRAY_SIZE(nmk_gpio_chips)
+
static void __nmk_gpio_set_mode(struct nmk_gpio_chip *nmk_chip,
unsigned offset, int gpio_mode)
{
@@ -138,8 +148,38 @@ static void __nmk_gpio_make_output(struct nmk_gpio_chip *nmk_chip,
__nmk_gpio_set_output(nmk_chip, offset, val);
}
+static void __nmk_gpio_set_mode_safe(struct nmk_gpio_chip *nmk_chip,
+ unsigned offset, int gpio_mode,
+ bool glitch)
+{
+ u32 rwimsc;
+ u32 fwimsc;
+
+ if (glitch && nmk_chip->set_ioforce) {
+ u32 bit = BIT(offset);
+
+ rwimsc = readl(nmk_chip->addr + NMK_GPIO_RWIMSC);
+ fwimsc = readl(nmk_chip->addr + NMK_GPIO_FWIMSC);
+
+ /* Prevent spurious wakeups */
+ writel(rwimsc & ~bit, nmk_chip->addr + NMK_GPIO_RWIMSC);
+ writel(fwimsc & ~bit, nmk_chip->addr + NMK_GPIO_FWIMSC);
+
+ nmk_chip->set_ioforce(true);
+ }
+
+ __nmk_gpio_set_mode(nmk_chip, offset, gpio_mode);
+
+ if (glitch && nmk_chip->set_ioforce) {
+ nmk_chip->set_ioforce(false);
+
+ writel(rwimsc, nmk_chip->addr + NMK_GPIO_RWIMSC);
+ writel(fwimsc, nmk_chip->addr + NMK_GPIO_FWIMSC);
+ }
+}
+
static void __nmk_config_pin(struct nmk_gpio_chip *nmk_chip, unsigned offset,
- pin_cfg_t cfg, bool sleep)
+ pin_cfg_t cfg, bool sleep, unsigned int *slpmregs)
{
static const char *afnames[] = {
[NMK_GPIO_ALT_GPIO] = "GPIO",
@@ -164,6 +204,7 @@ static void __nmk_config_pin(struct nmk_gpio_chip *nmk_chip, unsigned offset,
int slpm = PIN_SLPM(cfg);
int output = PIN_DIR(cfg);
int val = PIN_VAL(cfg);
+ bool glitch = af == NMK_GPIO_ALT_C;
dev_dbg(nmk_chip->chip.dev, "pin %d [%#lx]: af %s, pull %s, slpm %s (%s%s)\n",
pin, cfg, afnames[af], pullnames[pull], slpmnames[slpm],
@@ -202,8 +243,116 @@ static void __nmk_config_pin(struct nmk_gpio_chip *nmk_chip, unsigned offset,
__nmk_gpio_set_pull(nmk_chip, offset, pull);
}
- __nmk_gpio_set_slpm(nmk_chip, offset, slpm);
- __nmk_gpio_set_mode(nmk_chip, offset, af);
+ /*
+ * If we've backed up the SLPM registers (glitch workaround), modify
+ * the backups since they will be restored.
+ */
+ if (slpmregs) {
+ if (slpm == NMK_GPIO_SLPM_NOCHANGE)
+ slpmregs[nmk_chip->bank] |= BIT(offset);
+ else
+ slpmregs[nmk_chip->bank] &= ~BIT(offset);
+ } else
+ __nmk_gpio_set_slpm(nmk_chip, offset, slpm);
+
+ __nmk_gpio_set_mode_safe(nmk_chip, offset, af, glitch);
+}
+
+/*
+ * Safe sequence used to switch IOs between GPIO and Alternate-C mode:
+ * - Save SLPM registers
+ * - Set SLPM=0 for the IOs you want to switch and others to 1
+ * - Configure the GPIO registers for the IOs that are being switched
+ * - Set IOFORCE=1
+ * - Modify the AFLSA/B registers for the IOs that are being switched
+ * - Set IOFORCE=0
+ * - Restore SLPM registers
+ * - Any spurious wake up event during switch sequence to be ignored and
+ * cleared
+ */
+static void nmk_gpio_glitch_slpm_init(unsigned int *slpm)
+{
+ int i;
+
+ for (i = 0; i < NUM_BANKS; i++) {
+ struct nmk_gpio_chip *chip = nmk_gpio_chips[i];
+ unsigned int temp = slpm[i];
+
+ if (!chip)
+ break;
+
+ slpm[i] = readl(chip->addr + NMK_GPIO_SLPC);
+ writel(temp, chip->addr + NMK_GPIO_SLPC);
+ }
+}
+
+static void nmk_gpio_glitch_slpm_restore(unsigned int *slpm)
+{
+ int i;
+
+ for (i = 0; i < NUM_BANKS; i++) {
+ struct nmk_gpio_chip *chip = nmk_gpio_chips[i];
+
+ if (!chip)
+ break;
+
+ writel(slpm[i], chip->addr + NMK_GPIO_SLPC);
+ }
+}
+
+static int __nmk_config_pins(pin_cfg_t *cfgs, int num, bool sleep)
+{
+ static unsigned int slpm[NUM_BANKS];
+ unsigned long flags;
+ bool glitch = false;
+ int ret = 0;
+ int i;
+
+ for (i = 0; i < num; i++) {
+ if (PIN_ALT(cfgs[i]) == NMK_GPIO_ALT_C) {
+ glitch = true;
+ break;
+ }
+ }
+
+ spin_lock_irqsave(&nmk_gpio_slpm_lock, flags);
+
+ if (glitch) {
+ memset(slpm, 0xff, sizeof(slpm));
+
+ for (i = 0; i < num; i++) {
+ int pin = PIN_NUM(cfgs[i]);
+ int offset = pin % NMK_GPIO_PER_CHIP;
+
+ if (PIN_ALT(cfgs[i]) == NMK_GPIO_ALT_C)
+ slpm[pin / NMK_GPIO_PER_CHIP] &= ~BIT(offset);
+ }
+
+ nmk_gpio_glitch_slpm_init(slpm);
+ }
+
+ for (i = 0; i < num; i++) {
+ struct nmk_gpio_chip *nmk_chip;
+ int pin = PIN_NUM(cfgs[i]);
+
+ nmk_chip = get_irq_chip_data(NOMADIK_GPIO_TO_IRQ(pin));
+ if (!nmk_chip) {
+ ret = -EINVAL;
+ break;
+ }
+
+ spin_lock(&nmk_chip->lock);
+ __nmk_config_pin(nmk_chip, pin - nmk_chip->chip.base,
+ cfgs[i], sleep, glitch ? slpm : NULL);
+ spin_unlock(&nmk_chip->lock);
+ }
+
+ if (glitch)
+ nmk_gpio_glitch_slpm_restore(slpm);
+
+ spin_unlock_irqrestore(&nmk_gpio_slpm_lock, flags);
+
+ return ret;
}
/**
@@ -222,19 +371,7 @@ static void __nmk_config_pin(struct nmk_gpio_chip *nmk_chip, unsigned offset,
*/
int nmk_config_pin(pin_cfg_t cfg, bool sleep)
{
- struct nmk_gpio_chip *nmk_chip;
- int gpio = PIN_NUM(cfg);
- unsigned long flags;
-
- nmk_chip = get_irq_chip_data(NOMADIK_GPIO_TO_IRQ(gpio));
- if (!nmk_chip)
- return -EINVAL;
-
- spin_lock_irqsave(&nmk_chip->lock, flags);
- __nmk_config_pin(nmk_chip, gpio - nmk_chip->chip.base, cfg, sleep);
- spin_unlock_irqrestore(&nmk_chip->lock, flags);
-
- return 0;
+ return __nmk_config_pins(&cfg, 1, sleep);
}
EXPORT_SYMBOL(nmk_config_pin);
@@ -248,31 +385,13 @@ EXPORT_SYMBOL(nmk_config_pin);
*/
int nmk_config_pins(pin_cfg_t *cfgs, int num)
{
- int ret = 0;
- int i;
-
- for (i = 0; i < num; i++) {
- ret = nmk_config_pin(cfgs[i], false);
- if (ret)
- break;
- }
-
- return ret;
+ return __nmk_config_pins(cfgs, num, false);
}
EXPORT_SYMBOL(nmk_config_pins);
int nmk_config_pins_sleep(pin_cfg_t *cfgs, int num)
{
- int ret = 0;
- int i;
-
- for (i = 0; i < num; i++) {
- ret = nmk_config_pin(cfgs[i], true);
- if (ret)
- break;
- }
-
- return ret;
+ return __nmk_config_pins(cfgs, num, true);
}
EXPORT_SYMBOL(nmk_config_pins_sleep);
@@ -299,9 +418,13 @@ int nmk_gpio_set_slpm(int gpio, enum nmk_gpio_slpm mode)
if (!nmk_chip)
return -EINVAL;
- spin_lock_irqsave(&nmk_chip->lock, flags);
+ spin_lock_irqsave(&nmk_gpio_slpm_lock, flags);
+ spin_lock(&nmk_chip->lock);
+
__nmk_gpio_set_slpm(nmk_chip, gpio - nmk_chip->chip.base, mode);
- spin_unlock_irqrestore(&nmk_chip->lock, flags);
+
+ spin_unlock(&nmk_chip->lock);
+ spin_unlock_irqrestore(&nmk_gpio_slpm_lock, flags);
return 0;
}
@@ -474,7 +597,9 @@ static int nmk_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
if (!nmk_chip)
return -EINVAL;
- spin_lock_irqsave(&nmk_chip->lock, flags);
+ spin_lock_irqsave(&nmk_gpio_slpm_lock, flags);
+ spin_lock(&nmk_chip->lock);
+
#ifdef CONFIG_ARCH_U8500
if (cpu_is_u8500v2()) {
__nmk_gpio_set_slpm(nmk_chip, gpio,
@@ -483,7 +608,9 @@ static int nmk_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
}
#endif
__nmk_gpio_irq_modify(nmk_chip, gpio, WAKE, on);
- spin_unlock_irqrestore(&nmk_chip->lock, flags);
+
+ spin_unlock(&nmk_chip->lock);
+ spin_unlock_irqrestore(&nmk_gpio_slpm_lock, flags);
return 0;
}
@@ -826,6 +953,7 @@ static int __devinit nmk_gpio_probe(struct platform_device *dev)
nmk_chip->parent_irq = irq;
nmk_chip->secondary_parent_irq = secondary_irq;
nmk_chip->get_secondary_status = pdata->get_secondary_status;
+ nmk_chip->set_ioforce = pdata->set_ioforce;
spin_lock_init(&nmk_chip->lock);
chip = &nmk_chip->chip;
@@ -839,6 +967,9 @@ static int __devinit nmk_gpio_probe(struct platform_device *dev)
if (ret)
goto out_free;
+ BUG_ON(nmk_chip->bank >= ARRAY_SIZE(nmk_gpio_chips));
+
+ nmk_gpio_chips[nmk_chip->bank] = nmk_chip;
platform_set_drvdata(dev, nmk_chip);
nmk_gpio_init_irq(nmk_chip);
diff --git a/arch/arm/plat-nomadik/include/plat/gpio.h b/arch/arm/plat-nomadik/include/plat/gpio.h
index d108a326a0a..e3a4837e86f 100644
--- a/arch/arm/plat-nomadik/include/plat/gpio.h
+++ b/arch/arm/plat-nomadik/include/plat/gpio.h
@@ -84,6 +84,7 @@ struct nmk_gpio_platform_data {
int first_irq;
int num_gpio;
u32 (*get_secondary_status)(unsigned int bank);
+ void (*set_ioforce)(bool enable);
};
#endif /* __ASM_PLAT_GPIO_H */
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-14 20:07:42 +0000