mb/dell: Add Latitude E6400

Mainboard name is Compal JBL00. This is based on the GM45/ICH9M chipset
and uses DDR2 RAM. The EC is a SMSC MEC5035 which has internal flash, so
there's no issue about making sure to include the EC firmware in the
BIOS region. This only supports the variant with integrated graphics
only, the version with a discrete Nvidia Quadro NVS 160M is not
supported.
This port was based on the Lenovo T400 port.

Working:
- USB EHCI debug (lower USB port on right side)
- Keyboard
- Touchpad/trackpoint
- VGA
- Displayport
- ExpressCard
- Audio
- Ethernet
- mPCIe WiFi
- mPCIe Bluetooth (uses USB)

Not working:
- Brightness hotkeys
- Physical Wireless switch
- SD card slot: Linux outputs an "irq 18: nobody cared" message when
  inserting a card, after which it disables the IRQ

Unknown/untested:
- Dock
- Smartcard (slot and contactless)
- Firewire
- eSATA
- TPM
- Battery (my battery is at the end of its lifespan)

Signed-off-by: Nicholas Chin <nic.c3.14@gmail.com>
Change-Id: I516ebbf4390a3f6d242050da8d35dc267b8b3a28
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59704
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/src/mainboard/dell/e6400/blc.c b/src/mainboard/dell/e6400/blc.c
new file mode 100644
index 0000000000..b01d552850
--- /dev/null
+++ b/src/mainboard/dell/e6400/blc.c
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <commonlib/helpers.h>
+#include <northbridge/intel/gm45/gm45.h>
+
+/*
+ * This contains a list of panel IDs and a known well working
+ * backlight PWM frequency.
+ */
+static const struct blc_pwm_t blc_entries[] = {
+	/*
+	 * Not sure if that's just a corrupt byte or just something
+	 * weird about the EDID of the panel in my system. Also, the
+	 * vendor firmware sets the pwm frequency to a rather high
+	 * value compared to other GM45 systems in the tree.
+	 */
+	{"G022H\200141WX5", 12315},
+};
+
+int get_blc_values(const struct blc_pwm_t **entries)
+{
+	*entries = blc_entries;
+	return ARRAY_SIZE(blc_entries);
+}