acpi_pld: Make it easier to define the ACPI USB device groups

The Linux kernel can use the ACPI _PLD group information to
determine peer ports.  Currently to define the group information
the devicetree must provide a complete _PLD structure.  This
change pulls the group information into a separate structure that
can be defined in devicetree.  This makes it easier to set for
USB devices in devicetree that do not need a full custom PLD.

This was tested on a sarien board with the USB devices defined
by verifying that the USB 2/3 ports are correctly identified
with their peer in sysfs.

Change-Id: Ifd4cadf0f6c901eb3832ad4e1395904f99c2f5a0
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/c/29998
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/arch/x86/acpi_pld.c

@@ -18,7 +18,8 @@
 #include <arch/acpi.h>
 #include <arch/acpi_pld.h>
 
-int acpi_pld_fill_usb(struct acpi_pld *pld, enum acpi_upc_type type)
+int acpi_pld_fill_usb(struct acpi_pld *pld, enum acpi_upc_type type,
+		      struct acpi_pld_group *group)
 {
 	if (!pld)
 		return -1;
@@ -32,6 +33,8 @@ int acpi_pld_fill_usb(struct acpi_pld *pld, enum acpi_upc_type type)
 	pld->horizontal_position = PLD_HORIZONTAL_POSITION_CENTER;
 	pld->rotation = PLD_ROTATE_0;
 	pld->visible = 1;
+	pld->group.token = group->token;
+	pld->group.position = group->position;
 
 	/* Set the shape based on port type */
 	switch (type) {
@@ -114,16 +117,16 @@ int acpi_pld_to_buffer(const struct acpi_pld *pld, uint8_t *buf, int buf_len)
 	/* [77:74] Shape */
 	buf[9] |= (pld->shape & 0xf) << 2;
 
-	/* [78] Group Orientation */
+	/* [78] Orientation */
-	buf[9] |= (pld->group_orientation & 0x1) << 6;
+	buf[9] |= (pld->orientation & 0x1) << 6;
 
 	/* [86:79] Group Token (incorrectly defined as 1 bit in ACPI 6.2A) */
-	buf[9] |= (pld->group_token & 0x1) << 7;
+	buf[9] |= (pld->group.token & 0x1) << 7;
-	buf[10] |= (pld->group_token >> 0x1) & 0x7f;
+	buf[10] |= (pld->group.token >> 0x1) & 0x7f;
 
 	/* [94:87] Group Position */
-	buf[10] |= (pld->group_position & 0x1) << 7;
+	buf[10] |= (pld->group.position & 0x1) << 7;
-	buf[11] |= (pld->group_position >> 0x1) & 0x7f;
+	buf[11] |= (pld->group.position >> 0x1) & 0x7f;
 
 	/* [95] Bay */
 	buf[11] |= (pld->bay & 0x1) << 7;

src/arch/x86/include/arch/acpi_pld.h

@@ -75,6 +75,17 @@ enum acpi_pld_rotate {
 	PLD_ROTATE_315
 };
 
+#define ACPI_PLD_GROUP(__token, __position)	\
+	{					\
+		.token = __token,		\
+		.position = __position,		\
+	}
+
+struct acpi_pld_group {
+	uint8_t token;
+	uint8_t position;
+};
+
 struct acpi_pld {
 	/* Color field can be explicitly ignored */
 	bool ignore_color;
@@ -100,9 +111,8 @@ struct acpi_pld {
 	enum acpi_pld_rotate rotation;
 
 	/* Port grouping */
-	enum acpi_pld_orientation group_orientation;
+	enum acpi_pld_orientation orientation;
-	uint8_t group_token;
+	struct acpi_pld_group group;
-	uint8_t group_position;
 	uint8_t draw_order;
 	uint8_t cabinet_number;
 	uint8_t card_cage_number;
@@ -112,7 +122,8 @@ struct acpi_pld {
 };
 
 /* Fill out PLD structure with defaults based on USB port type */
-int acpi_pld_fill_usb(struct acpi_pld *pld, enum acpi_upc_type type);
+int acpi_pld_fill_usb(struct acpi_pld *pld, enum acpi_upc_type type,
+		      struct acpi_pld_group *group);
 
 /* Turn PLD structure into a 20 byte ACPI buffer */
 int acpi_pld_to_buffer(const struct acpi_pld *pld, uint8_t *buf, int buf_len);

src/drivers/usb/acpi/chip.h

@@ -46,7 +46,13 @@ struct drivers_usb_acpi_config {
 	 */
 	enum acpi_upc_type type;
 
-	/* Define a custom physical location for the port */
+	/* Group peer ports */
+	struct acpi_pld_group group;
+
+	/*
+	 * Define a custom physical location for the port.
+	 * If enabled, this takes precedence over the 'group' field.
+	 */
 	bool use_custom_pld;
 	struct acpi_pld custom_pld;
 

src/drivers/usb/acpi/usb_acpi.c

@@ -57,7 +57,7 @@ static void usb_acpi_fill_ssdt_generator(struct device *dev)
 	} else {
 		/* Fill PLD strucutre based on port type */
 		struct acpi_pld pld;
-		acpi_pld_fill_usb(&pld, config->type);
+		acpi_pld_fill_usb(&pld, config->type, &config->group);
 		acpigen_write_pld(&pld);
 	}