ARM: at91/pio: add new PIO3 features

This patch adds the support for new PIO controller found on some
at91sam SOCs.
- more peripheral multiplexing
- more features to configure on a PIO (pull-down, Schmitt trigger, debouncer)
- support for several IRQ triggering features (type and polarity)

Support for those new features are retrieved from the device tree
compatibility string.

Debugfs at91_gpio file is updated to monitor configuration.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

1 files changed, 246 insertions, 16 deletions

diff --git a/arch/arm/mach-at91/gpio.c b/arch/arm/mach-at91/gpio.c
index 567df654a2e1..325837a264c9 100644
--- a/arch/arm/mach-at91/gpio.c
+++ b/arch/arm/mach-at91/gpio.c
@@ -76,6 +76,14 @@ static struct at91_gpio_chip gpio_chip[] = {
 };
 
 static int gpio_banks;
+static unsigned long at91_gpio_caps;
+
+/* All PIO controllers support PIO3 features */
+#define AT91_GPIO_CAP_PIO3      (1 <<  0)
+
+#define has_pio3()      (at91_gpio_caps & AT91_GPIO_CAP_PIO3)
+
+/*--------------------------------------------------------------------------*/
 
 static inline void __iomem *pin_to_controller(unsigned pin)
 {
@@ -92,6 +100,25 @@ static inline unsigned pin_to_mask(unsigned pin)
 }
 
 
+static char peripheral_function(void __iomem *pio, unsigned mask)
+{
+        char    ret = 'X';
+        u8      select;
+
+        if (pio) {
+                if (has_pio3()) {
+                        select = !!(__raw_readl(pio + PIO_ABCDSR1) & mask);
+                        select |= (!!(__raw_readl(pio + PIO_ABCDSR2) & mask) << 1);
+                        ret = 'A' + select;
+                } else {
+                        ret = __raw_readl(pio + PIO_ABSR) & mask ?
+                                                        'B' : 'A';
+                }
+        }
+
+        return ret;
+}
+
 /*--------------------------------------------------------------------------*/
 
 /* Not all hardware capabilities are exposed through these calls; they
@@ -139,7 +166,14 @@ int __init_or_module at91_set_A_periph(unsigned pin, int use_pullup)
 
         __raw_writel(mask, pio + PIO_IDR);
         __raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
-        __raw_writel(mask, pio + PIO_ASR);
+        if (has_pio3()) {
+                __raw_writel(__raw_readl(pio + PIO_ABCDSR1) & ~mask,
+                                                        pio + PIO_ABCDSR1);
+                __raw_writel(__raw_readl(pio + PIO_ABCDSR2) & ~mask,
+                                                        pio + PIO_ABCDSR2);
+        } else {
+                __raw_writel(mask, pio + PIO_ASR);
+        }
         __raw_writel(mask, pio + PIO_PDR);
         return 0;
 }
@@ -159,7 +193,14 @@ int __init_or_module at91_set_B_periph(unsigned pin, int use_pullup)
 
         __raw_writel(mask, pio + PIO_IDR);
         __raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
-        __raw_writel(mask, pio + PIO_BSR);
+        if (has_pio3()) {
+                __raw_writel(__raw_readl(pio + PIO_ABCDSR1) | mask,
+                                                        pio + PIO_ABCDSR1);
+                __raw_writel(__raw_readl(pio + PIO_ABCDSR2) & ~mask,
+                                                        pio + PIO_ABCDSR2);
+        } else {
+                __raw_writel(mask, pio + PIO_BSR);
+        }
         __raw_writel(mask, pio + PIO_PDR);
         return 0;
 }
@@ -167,8 +208,50 @@ EXPORT_SYMBOL(at91_set_B_periph);
 
 
 /*
- * mux the pin to the gpio controller (instead of "A" or "B" peripheral), and
- * configure it for an input.
+ * mux the pin to the "C" internal peripheral role.
+ */
+int __init_or_module at91_set_C_periph(unsigned pin, int use_pullup)
+{
+        void __iomem    *pio = pin_to_controller(pin);
+        unsigned        mask = pin_to_mask(pin);
+
+        if (!pio || !has_pio3())
+                return -EINVAL;
+
+        __raw_writel(mask, pio + PIO_IDR);
+        __raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
+        __raw_writel(__raw_readl(pio + PIO_ABCDSR1) & ~mask, pio + PIO_ABCDSR1);
+        __raw_writel(__raw_readl(pio + PIO_ABCDSR2) | mask, pio + PIO_ABCDSR2);
+        __raw_writel(mask, pio + PIO_PDR);
+        return 0;
+}
+EXPORT_SYMBOL(at91_set_C_periph);
+
+
+/*
+ * mux the pin to the "D" internal peripheral role.
+ */
+int __init_or_module at91_set_D_periph(unsigned pin, int use_pullup)
+{
+        void __iomem    *pio = pin_to_controller(pin);
+        unsigned        mask = pin_to_mask(pin);
+
+        if (!pio || !has_pio3())
+                return -EINVAL;
+
+        __raw_writel(mask, pio + PIO_IDR);
+        __raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
+        __raw_writel(__raw_readl(pio + PIO_ABCDSR1) | mask, pio + PIO_ABCDSR1);
+        __raw_writel(__raw_readl(pio + PIO_ABCDSR2) | mask, pio + PIO_ABCDSR2);
+        __raw_writel(mask, pio + PIO_PDR);
+        return 0;
+}
+EXPORT_SYMBOL(at91_set_D_periph);
+
+
+/*
+ * mux the pin to the gpio controller (instead of "A", "B", "C"
+ * or "D" peripheral), and configure it for an input.
  */
 int __init_or_module at91_set_gpio_input(unsigned pin, int use_pullup)
 {
@@ -188,8 +271,8 @@ EXPORT_SYMBOL(at91_set_gpio_input);
 
 
 /*
- * mux the pin to the gpio controller (instead of "A" or "B" peripheral),
- * and configure it for an output.
+ * mux the pin to the gpio controller (instead of "A", "B", "C"
+ * or "D" peripheral), and configure it for an output.
  */
 int __init_or_module at91_set_gpio_output(unsigned pin, int value)
 {
@@ -219,12 +302,37 @@ int __init_or_module at91_set_deglitch(unsigned pin, int is_on)
 
         if (!pio)
                 return -EINVAL;
+
+        if (has_pio3() && is_on)
+                __raw_writel(mask, pio + PIO_IFSCDR);
         __raw_writel(mask, pio + (is_on ? PIO_IFER : PIO_IFDR));
         return 0;
 }
 EXPORT_SYMBOL(at91_set_deglitch);
 
 /*
+ * enable/disable the debounce filter;
+ */
+int __init_or_module at91_set_debounce(unsigned pin, int is_on, int div)
+{
+        void __iomem    *pio = pin_to_controller(pin);
+        unsigned        mask = pin_to_mask(pin);
+
+        if (!pio || !has_pio3())
+                return -EINVAL;
+
+        if (is_on) {
+                __raw_writel(mask, pio + PIO_IFSCER);
+                __raw_writel(div & PIO_SCDR_DIV, pio + PIO_SCDR);
+                __raw_writel(mask, pio + PIO_IFER);
+        } else {
+                __raw_writel(mask, pio + PIO_IFDR);
+        }
+        return 0;
+}
+EXPORT_SYMBOL(at91_set_debounce);
+
+/*
  * enable/disable the multi-driver; This is only valid for output and
  * allows the output pin to run as an open collector output.
  */
@@ -242,6 +350,41 @@ int __init_or_module at91_set_multi_drive(unsigned pin, int is_on)
 EXPORT_SYMBOL(at91_set_multi_drive);
 
 /*
+ * enable/disable the pull-down.
+ * If pull-up already enabled while calling the function, we disable it.
+ */
+int __init_or_module at91_set_pulldown(unsigned pin, int is_on)
+{
+        void __iomem    *pio = pin_to_controller(pin);
+        unsigned        mask = pin_to_mask(pin);
+
+        if (!pio || !has_pio3())
+                return -EINVAL;
+
+        /* Disable pull-up anyway */
+        __raw_writel(mask, pio + PIO_PUDR);
+        __raw_writel(mask, pio + (is_on ? PIO_PPDER : PIO_PPDDR));
+        return 0;
+}
+EXPORT_SYMBOL(at91_set_pulldown);
+
+/*
+ * disable Schmitt trigger
+ */
+int __init_or_module at91_disable_schmitt_trig(unsigned pin)
+{
+        void __iomem    *pio = pin_to_controller(pin);
+        unsigned        mask = pin_to_mask(pin);
+
+        if (!pio || !has_pio3())
+                return -EINVAL;
+
+        __raw_writel(__raw_readl(pio + PIO_SCHMITT) | mask, pio + PIO_SCHMITT);
+        return 0;
+}
+EXPORT_SYMBOL(at91_disable_schmitt_trig);
+
+/*
  * assuming the pin is muxed as a gpio output, set its value.
  */
 int at91_set_gpio_value(unsigned pin, int value)
@@ -347,7 +490,10 @@ void at91_gpio_resume(void)
  * To use any AT91_PIN_* as an externally triggered IRQ, first call
  * at91_set_gpio_input() then maybe enable its glitch filter.
  * Then just request_irq() with the pin ID; it works like any ARM IRQ
- * handler, though it always triggers on rising and falling edges.
+ * handler.
+ * First implementation always triggers on rising and falling edges
+ * whereas the newer PIO3 can be additionally configured to trigger on
+ * level, edge with any polarity.
  *
  * Alternatively, certain pins may be used directly as IRQ0..IRQ6 after
  * configuring them with at91_set_a_periph() or at91_set_b_periph().
@@ -385,12 +531,55 @@ static int gpio_irq_type(struct irq_data *d, unsigned type)
         }
 }
 
+/* Alternate irq type for PIO3 support */
+static int alt_gpio_irq_type(struct irq_data *d, unsigned type)
+{
+        struct at91_gpio_chip *at91_gpio = irq_data_get_irq_chip_data(d);
+        void __iomem    *pio = at91_gpio->regbase;
+        unsigned        mask = 1 << d->hwirq;
+
+        switch (type) {
+        case IRQ_TYPE_EDGE_RISING:
+                __raw_writel(mask, pio + PIO_ESR);
+                __raw_writel(mask, pio + PIO_REHLSR);
+                break;
+        case IRQ_TYPE_EDGE_FALLING:
+                __raw_writel(mask, pio + PIO_ESR);
+                __raw_writel(mask, pio + PIO_FELLSR);
+                break;
+        case IRQ_TYPE_LEVEL_LOW:
+                __raw_writel(mask, pio + PIO_LSR);
+                __raw_writel(mask, pio + PIO_FELLSR);
+                break;
+        case IRQ_TYPE_LEVEL_HIGH:
+                __raw_writel(mask, pio + PIO_LSR);
+                __raw_writel(mask, pio + PIO_REHLSR);
+                break;
+        case IRQ_TYPE_EDGE_BOTH:
+                /*
+                 * disable additional interrupt modes:
+                 * fall back to default behavior
+                 */
+                __raw_writel(mask, pio + PIO_AIMDR);
+                return 0;
+        case IRQ_TYPE_NONE:
+        default:
+                pr_warn("AT91: No type for irq %d\n", gpio_to_irq(d->irq));
+                return -EINVAL;
+        }
+
+        /* enable additional interrupt modes */
+        __raw_writel(mask, pio + PIO_AIMER);
+
+        return 0;
+}
+
 static struct irq_chip gpio_irqchip = {
         .name           = "GPIO",
         .irq_disable    = gpio_irq_mask,
         .irq_mask       = gpio_irq_mask,
         .irq_unmask     = gpio_irq_unmask,
-        .irq_set_type   = gpio_irq_type,
+        /* .irq_set_type is set dynamically */
         .irq_set_wake   = gpio_irq_set_wake,
 };
 
@@ -433,6 +622,33 @@ static void gpio_irq_handler(unsigned irq, struct irq_desc *desc)
 
 #ifdef CONFIG_DEBUG_FS
 
+static void gpio_printf(struct seq_file *s, void __iomem *pio, unsigned mask)
+{
+        char    *trigger = NULL;
+        char    *polarity = NULL;
+
+        if (__raw_readl(pio + PIO_IMR) & mask) {
+                if (!has_pio3() || !(__raw_readl(pio + PIO_AIMMR) & mask )) {
+                        trigger = "edge";
+                        polarity = "both";
+                } else {
+                        if (__raw_readl(pio + PIO_ELSR) & mask) {
+                                trigger = "level";
+                                polarity = __raw_readl(pio + PIO_FRLHSR) & mask ?
+                                        "high" : "low";
+                        } else {
+                                trigger = "edge";
+                                polarity = __raw_readl(pio + PIO_FRLHSR) & mask ?
+                                                "rising" : "falling";
+                        }
+                }
+                seq_printf(s, "IRQ:%s-%s\t", trigger, polarity);
+        } else {
+                seq_printf(s, "GPIO:%s\t\t",
+                                __raw_readl(pio + PIO_PDSR) & mask ? "1" : "0");
+        }
+}
+
 static int at91_gpio_show(struct seq_file *s, void *unused)
 {
         int bank, j;
@@ -440,7 +656,7 @@ static int at91_gpio_show(struct seq_file *s, void *unused)
         /* print heading */
         seq_printf(s, "Pin\t");
         for (bank = 0; bank < gpio_banks; bank++) {
-                seq_printf(s, "PIO%c\t", 'A' + bank);
+                seq_printf(s, "PIO%c\t\t", 'A' + bank);
         };
         seq_printf(s, "\n\n");
 
@@ -454,11 +670,10 @@ static int at91_gpio_show(struct seq_file *s, void *unused)
                         unsigned        mask = pin_to_mask(pin);
 
                         if (__raw_readl(pio + PIO_PSR) & mask)
-                                seq_printf(s, "GPIO:%s", __raw_readl(pio + PIO_PDSR) & mask ? "1" : "0");
+                                gpio_printf(s, pio, mask);
                         else
-                                seq_printf(s, "%s", __raw_readl(pio + PIO_ABSR) & mask ? "B" : "A");
-
-                        seq_printf(s, "\t");
+                                seq_printf(s, "%c\t\t",
+                                                peripheral_function(pio, mask));
                 }
 
                 seq_printf(s, "\n");
@@ -529,6 +744,12 @@ int __init at91_gpio_of_irq_setup(struct device_node *node,
         int                     alias_idx = of_alias_get_id(node, "gpio");
         struct at91_gpio_chip   *at91_gpio = &gpio_chip[alias_idx];
 
+        /* Setup proper .irq_set_type function */
+        if (has_pio3())
+                gpio_irqchip.irq_set_type = alt_gpio_irq_type;
+        else
+                gpio_irqchip.irq_set_type = gpio_irq_type;
+
         /* Disable irqs of this PIO controller */
         __raw_writel(~0, at91_gpio->regbase + PIO_IDR);
 
@@ -593,6 +814,12 @@ void __init at91_gpio_irq_setup(void)
         int                     gpio_irqnbr = 0;
         struct at91_gpio_chip   *this, *prev;
 
+        /* Setup proper .irq_set_type function */
+        if (has_pio3())
+                gpio_irqchip.irq_set_type = alt_gpio_irq_type;
+        else
+                gpio_irqchip.irq_set_type = gpio_irq_type;
+
         for (pioc = 0, this = gpio_chip, prev = NULL;
                         pioc++ < gpio_banks;
                         prev = this, this++) {
@@ -696,9 +923,8 @@ static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
                                            at91_get_gpio_value(pin) ?
                                            "set" : "clear");
                         else
-                                seq_printf(s, "[periph %s]\n",
-                                           __raw_readl(pio + PIO_ABSR) &
-                                           mask ? "B" : "A");
+                                seq_printf(s, "[periph %c]\n",
+                                           peripheral_function(pio, mask));
                 }
         }
 }
@@ -781,6 +1007,10 @@ static void __init of_at91_gpio_init_one(struct device_node *np)
                 goto ioremap_err;
         }
 
+        /* Get capabilities from compatibility property */
+        if (of_device_is_compatible(np, "atmel,at91sam9x5-gpio"))
+                at91_gpio_caps |= AT91_GPIO_CAP_PIO3;
+
         /* Setup clock */
         if (at91_gpio_setup_clk(alias_idx))
                 goto ioremap_err;