mb/up/squared: Make mini PCIe port mode configurable

Add config choice menu and pad configuration to put Mini PCIe port into
mSATA mode.

The vendor firmware's "Chipset->Mini PCIe / mSATA Switch" option has
been used together with the output of inteltool and intel2pm to deduce
the exact pad configuration.

Note: the vendor firmware does not autodetect the mode, and the default
setting for the port is "Mini PCIe".

Tested with Kingston SUV500MS120G mSATA SSD.

Change-Id: Ic2da1dd4252ebb5e373bc65418e321f566d4c10f
Signed-off-by: Reto Buerki <reet@codelabs.ch>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80261
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/mainboard/up/squared/Kconfig

@@ -76,4 +76,22 @@ config CONSOLE_POST
 	bool
 	default y
 
+choice
+	prompt "Mini PCIe port mode"
+	default MINI_PCIE_MODE_PCIE
+	help
+	  Choose the operating mode of the mini PCIe port.
+
+config MINI_PCIE_MODE_PCIE
+	bool "PCIe"
+	help
+	  Select this option to leave the mini PCIe port in PCIe mode. This is
+	  also the default mode of the vendor firmware.
+
+config MINI_PCIE_MODE_MSATA
+	bool "mSATA"
+	help
+	  Select this option to put the mini PCIe port into mSATA mode.
+endchoice
+
 endif

src/mainboard/up/squared/gpio.h

@@ -777,4 +777,14 @@ static const struct pad_config gpio_table[] = {
 	PAD_CFG_NF_IOSSTATE_IOSTERM(GPIO_43, UP_20K, DEEP, NF1, HIZCRx0, DISPUPD),
 };
 
+/*
+ * Pad configuration to put MiniPCIe port into mSATA mode.
+ */
+static const struct pad_config msata_mode_gpio_table[] = {
+	/*  ------- GPIO Group North-West ------- */
+
+	/* GPIO_213 - GPIO */
+	PAD_CFG_TERM_GPO(GPIO_213, 0, UP_20K, DEEP),
+};
+
 #endif /* CFG_GPIO_H */

src/mainboard/up/squared/romstage.c

@@ -103,6 +103,8 @@ void mainboard_memory_init_params(FSPM_UPD *memupd)
 	FSP_M_CONFIG *config = &memupd->FspmConfig;
 
 	gpio_configure_pads(gpio_table, ARRAY_SIZE(gpio_table));
+	if (CONFIG(MINI_PCIE_MODE_MSATA))
+		gpio_configure_pads(msata_mode_gpio_table, ARRAY_SIZE(msata_mode_gpio_table));
 
 	uint8_t memory_skuid = get_memory_skuid();
 	printk(BIOS_DEBUG, "MAINBOARD: Found memory SKU ID: 0x%02x\n", memory_skuid);