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Diffstat (limited to 'board/LaCie/common/cpld-gpio-bus.c')
-rw-r--r--board/LaCie/common/cpld-gpio-bus.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/board/LaCie/common/cpld-gpio-bus.c b/board/LaCie/common/cpld-gpio-bus.c
new file mode 100644
index 0000000..fb9bf8d
--- /dev/null
+++ b/board/LaCie/common/cpld-gpio-bus.c
@@ -0,0 +1,50 @@
+/*
+ * cpld-gpio-bus.c: provides support for the CPLD GPIO bus found on some LaCie
+ * boards (as the 2Big/5Big Network v2 and the 2Big NAS). This parallel GPIO
+ * bus exposes two registers (address and data). Each of this register is made
+ * up of several dedicated GPIOs. An extra GPIO is used to notify the CPLD that
+ * the registers have been updated.
+ *
+ * Mostly this bus is used to configure the LEDs on LaCie boards.
+ *
+ * Copyright (C) 2013 Simon Guinot <simon.guinot@sequanux.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#include <asm/arch/gpio.h>
+#include "cpld-gpio-bus.h"
+
+static void cpld_gpio_bus_set_addr(struct cpld_gpio_bus *bus, unsigned addr)
+{
+ int pin;
+
+ for (pin = 0; pin < bus->num_addr; pin++)
+ kw_gpio_set_value(bus->addr[pin], (addr >> pin) & 1);
+}
+
+static void cpld_gpio_bus_set_data(struct cpld_gpio_bus *bus, unsigned data)
+{
+ int pin;
+
+ for (pin = 0; pin < bus->num_data; pin++)
+ kw_gpio_set_value(bus->data[pin], (data >> pin) & 1);
+}
+
+static void cpld_gpio_bus_enable_select(struct cpld_gpio_bus *bus)
+{
+ /* The transfer is enabled on the raising edge. */
+ kw_gpio_set_value(bus->enable, 0);
+ kw_gpio_set_value(bus->enable, 1);
+}
+
+void cpld_gpio_bus_write(struct cpld_gpio_bus *bus,
+ unsigned addr, unsigned value)
+{
+ cpld_gpio_bus_set_addr(bus, addr);
+ cpld_gpio_bus_set_data(bus, value);
+ cpld_gpio_bus_enable_select(bus);
+}