Blackfin: bf538: add support for extended GPIO banks

The GPIOs on ports C/D/E on the BF538/BF539 do not behave the same way as
the other ports on the part and the same way as all other Blackfin parts.
The MMRs are programmed slightly different and they cannot be used to
generate interrupts or wakeup a sleeping system.  Since these guys don't
fit into the existing code, create a simple gpiolib driver for them.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 97 insertions, 0 deletions

diff --git a/arch/blackfin/kernel/bfin_gpio.c b/arch/blackfin/kernel/bfin_gpio.c
index c4161e03df78..a174596cc009 100644
--- a/arch/blackfin/kernel/bfin_gpio.c
+++ b/arch/blackfin/kernel/bfin_gpio.c
@@ -100,6 +100,12 @@ u8 pmux_offset[][16] = {
 };
 # endif
 
+#elif defined(BF538_FAMILY)
+static unsigned short * const port_fer[] = {
+        (unsigned short *) PORTCIO_FER,
+        (unsigned short *) PORTDIO_FER,
+        (unsigned short *) PORTEIO_FER,
+};
 #endif
 
 static unsigned short reserved_gpio_map[GPIO_BANK_NUM];
@@ -163,6 +169,27 @@ static int cmp_label(unsigned short ident, const char *label)
 
 static void port_setup(unsigned gpio, unsigned short usage)
 {
+#if defined(BF538_FAMILY)
+        /*
+         * BF538/9 Port C,D and E are special.
+         * Inverted PORT_FER polarity on CDE and no PORF_FER on F
+         * Regular PORT F GPIOs are handled here, CDE are exclusively
+         * managed by GPIOLIB
+         */
+
+        if (gpio < MAX_BLACKFIN_GPIOS || gpio >= MAX_RESOURCES)
+                return;
+
+        gpio -= MAX_BLACKFIN_GPIOS;
+
+        if (usage == GPIO_USAGE)
+                *port_fer[gpio_bank(gpio)] |= gpio_bit(gpio);
+        else
+                *port_fer[gpio_bank(gpio)] &= ~gpio_bit(gpio);
+        SSYNC();
+        return;
+#endif
+
         if (check_gpio(gpio))
                 return;
 
@@ -981,6 +1008,76 @@ void bfin_gpio_free(unsigned gpio)
 }
 EXPORT_SYMBOL(bfin_gpio_free);
 
+#ifdef BFIN_SPECIAL_GPIO_BANKS
+static unsigned short reserved_special_gpio_map[gpio_bank(MAX_RESOURCES)];
+
+int bfin_special_gpio_request(unsigned gpio, const char *label)
+{
+        unsigned long flags;
+
+        local_irq_save_hw(flags);
+
+        /*
+         * Allow that the identical GPIO can
+         * be requested from the same driver twice
+         * Do nothing and return -
+         */
+
+        if (cmp_label(gpio, label) == 0) {
+                local_irq_restore_hw(flags);
+                return 0;
+        }
+
+        if (unlikely(reserved_special_gpio_map[gpio_bank(gpio)] & gpio_bit(gpio))) {
+                local_irq_restore_hw(flags);
+                printk(KERN_ERR "bfin-gpio: GPIO %d is already reserved by %s !\n",
+                       gpio, get_label(gpio));
+
+                return -EBUSY;
+        }
+        if (unlikely(reserved_peri_map[gpio_bank(gpio)] & gpio_bit(gpio))) {
+                local_irq_restore_hw(flags);
+                printk(KERN_ERR
+                       "bfin-gpio: GPIO %d is already reserved as Peripheral by %s !\n",
+                       gpio, get_label(gpio));
+
+                return -EBUSY;
+        }
+
+        reserved_special_gpio_map[gpio_bank(gpio)] |= gpio_bit(gpio);
+        reserved_peri_map[gpio_bank(gpio)] |= gpio_bit(gpio);
+
+        set_label(gpio, label);
+        local_irq_restore_hw(flags);
+        port_setup(gpio, GPIO_USAGE);
+
+        return 0;
+}
+EXPORT_SYMBOL(bfin_special_gpio_request);
+
+void bfin_special_gpio_free(unsigned gpio)
+{
+        unsigned long flags;
+
+        might_sleep();
+
+        local_irq_save_hw(flags);
+
+        if (unlikely(!(reserved_special_gpio_map[gpio_bank(gpio)] & gpio_bit(gpio)))) {
+                gpio_error(gpio);
+                local_irq_restore_hw(flags);
+                return;
+        }
+
+        reserved_special_gpio_map[gpio_bank(gpio)] &= ~gpio_bit(gpio);
+        reserved_peri_map[gpio_bank(gpio)] &= ~gpio_bit(gpio);
+        set_label(gpio, "free");
+        local_irq_restore_hw(flags);
+}
+EXPORT_SYMBOL(bfin_special_gpio_free);
+#endif
+
+
 int bfin_gpio_irq_request(unsigned gpio, const char *label)
 {
         unsigned long flags;