pci: Add support for p2sb uclass

The Primary-to-Sideband bus (P2SB) is used to access various peripherals
through memory-mapped I/O in a large chunk of PCI space. The space is
segmented into different channels and peripherals are accessed by
device-specific means within those channels. Devices should be added in
the device tree as subnodes of the p2sb.

This adds a uclass and enables it for sandbox.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

1 files changed, 135 insertions, 0 deletions

diff --git a/include/p2sb.h b/include/p2sb.h
new file mode 100644
index 0000000000..60c7f70773
--- /dev/null
+++ b/include/p2sb.h
@@ -0,0 +1,135 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2019 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#ifndef __p2sb_h
+#define __p2sb_h
+
+/* Port Id lives in bits 23:16 and register offset lives in 15:0 of address */
+#define PCR_PORTID_SHIFT	16
+
+/**
+ * struct p2sb_child_platdata - Information about each child of a p2sb device
+ *
+ * @pid: Port ID for this child
+ */
+struct p2sb_child_platdata {
+	uint pid;
+};
+
+/**
+ * struct p2sb_uc_priv - information for the uclass about each device
+ *
+ * This must be set up by the driver when it is probed
+ *
+ * @mmio_base: Base address of P2SB region
+ */
+struct p2sb_uc_priv {
+	uint mmio_base;
+};
+
+/**
+ * struct p2sb_ops - Operations for the P2SB (none at present)
+ */
+struct p2sb_ops {
+};
+
+#define p2sb_get_ops(dev)        ((struct p2sb_ops *)(dev)->driver->ops)
+
+/**
+ * pcr_read32/16/8() - Read from a PCR device
+ *
+ * Reads data from a PCR device within the P2SB
+ *
+ * @dev: Device to read from
+ * @offset: Offset within device to read
+ * @return value read
+ */
+uint pcr_read32(struct udevice *dev, uint offset);
+uint pcr_read16(struct udevice *dev, uint offset);
+uint pcr_read8(struct udevice *dev, uint offset);
+
+/**
+ * pcr_read32/16/8() - Write to a PCR device
+ *
+ * Writes data to a PCR device within the P2SB
+ *
+ * @dev: Device to write to
+ * @offset: Offset within device to write
+ * @data: Data to write
+ */
+void pcr_write32(struct udevice *dev, uint offset, uint data);
+void pcr_write16(struct udevice *dev, uint offset, uint data);
+void pcr_write8(struct udevice *dev, uint offset, uint data);
+
+/**
+ * pcr_clrsetbits32/16/8() - Update a PCR device
+ *
+ * Updates dat in a PCR device within the P2SB
+ *
+ * This reads from the device, clears and set bits, then writes back.
+ *
+ * new_data = (old_data & ~clr) | set
+ *
+ * @dev: Device to update
+ * @offset: Offset within device to update
+ * @clr: Bits to clear after reading
+ * @set: Bits to set before writing
+ */
+void pcr_clrsetbits32(struct udevice *dev, uint offset, uint clr, uint set);
+void pcr_clrsetbits16(struct udevice *dev, uint offset, uint clr, uint set);
+void pcr_clrsetbits8(struct udevice *dev, uint offset, uint clr, uint set);
+
+static inline void pcr_setbits32(struct udevice *dev, uint offset, uint set)
+{
+	return pcr_clrsetbits32(dev, offset, 0, set);
+}
+
+static inline void pcr_setbits16(struct udevice *dev, uint offset, uint set)
+{
+	return pcr_clrsetbits16(dev, offset, 0, set);
+}
+
+static inline void pcr_setbits8(struct udevice *dev, uint offset, uint set)
+{
+	return pcr_clrsetbits8(dev, offset, 0, set);
+}
+
+static inline void pcr_clrbits32(struct udevice *dev, uint offset, uint clr)
+{
+	return pcr_clrsetbits32(dev, offset, clr, 0);
+}
+
+static inline void pcr_clrbits16(struct udevice *dev, uint offset, uint clr)
+{
+	return pcr_clrsetbits16(dev, offset, clr, 0);
+}
+
+static inline void pcr_clrbits8(struct udevice *dev, uint offset, uint clr)
+{
+	return pcr_clrsetbits8(dev, offset, clr, 0);
+}
+
+/**
+ * p2sb_set_port_id() - Set the port ID for a p2sb child device
+ *
+ * This must be called in a device's bind() method when OF_PLATDATA is used
+ * since the uclass cannot access the device's of-platdata.
+ *
+ * @dev: Child device (whose parent is UCLASS_P2SB)
+ * @portid: Port ID of child device
+ * @return 0 if OK, -ENODEV is the p2sb device could not be found
+ */
+int p2sb_set_port_id(struct udevice *dev, int portid);
+
+/**
+ * p2sb_get_port_id() - Get the port ID for a p2sb child device
+ *
+ * @dev: Child device (whose parent is UCLASS_P2SB)
+ * @return Port ID of that child
+ */
+int p2sb_get_port_id(struct udevice *dev);
+
+#endif