Add support for S7 Elephant (#4511)

* Add support for S7 Elephant

A high-end 70% custom keyboard designed and produced by jacky from Geekhack.

* Polish S7 Elephant code

Implement drashna's suggestions:

- specify bootloader
- remove unnecessary defines
- use led_set_user() for LED logic

* Correct info.json and s7_elephant.h

Correct info.json and s7_elepant.h to follow QMK convention and fix a
missing curly bracket.

1 files changed, 52 insertions, 0 deletions

diff --git a/keyboards/s7_elephant/rules.mk b/keyboards/s7_elephant/rules.mk
new file mode 100644
index 000000000..7f0ad6d3c
--- /dev/null
+++ b/keyboards/s7_elephant/rules.mk
@@ -0,0 +1,52 @@
+# MCU name
+MCU = atmega32u4
+
+# Processor frequency.
+#     This will define a symbol, F_CPU, in all source code files equal to the
+#     processor frequency in Hz. You can then use this symbol in your source code to
+#     calculate timings. Do NOT tack on a 'UL' at the end, this will be done
+#     automatically to create a 32-bit value in your source code.
+#
+#     This will be an integer division of F_USB below, as it is sourced by
+#     F_USB after it has run through any CPU prescalers. Note that this value
+#     does not *change* the processor frequency - it should merely be updated to
+#     reflect the processor speed set externally so that the code can use accurate
+#     software delays.
+F_CPU = 16000000
+
+#
+# LUFA specific
+#
+# Target architecture (see library "Board Types" documentation).
+ARCH = AVR8
+
+# Input clock frequency.
+#     This will define a symbol, F_USB, in all source code files equal to the
+#     input clock frequency (before any prescaling is performed) in Hz. This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_USB = $(F_CPU)
+
+# Interrupt driven control endpoint task(+60)
+OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
+
+BOOTLOADER = atmel-dfu
+
+# Build Options
+#   comment out to disable the options.
+#
+BOOTMAGIC_ENABLE = no    # Virtual DIP switch configuration(+1000)
+MOUSEKEY_ENABLE = yes    # Mouse keys(+4700)
+EXTRAKEY_ENABLE = yes    # Audio control and System control(+450)
+CONSOLE_ENABLE = no      # Console for debug(+400)
+COMMAND_ENABLE = no      # Commands for debug and configuration
+SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
+NKRO_ENABLE = yes        # USB Nkey Rollover - if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
+BACKLIGHT_ENABLE = no    # Enable keyboard backlight functionality
+RGBLIGHT_ENABLE = yes    # Enable keyboard underlight functionality