thunderbolt: Add initial cactus ridge NHI support

Thunderbolt hotplug is supposed to be handled by the firmware. But Apple
decided to implement thunderbolt at the operating system level. The
firmare only initializes thunderbolt devices that are present at boot
time. This driver enables hotplug of thunderbolt of non-chained
thunderbolt devices on Apple systems with a cactus ridge controller.

This first patch adds the Kconfig file as well the parts of the driver
which talk directly to the hardware (that is pci device setup, interrupt
handling and RX/TX ring management).

Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 101 insertions, 0 deletions

diff --git a/drivers/thunderbolt/nhi_regs.h b/drivers/thunderbolt/nhi_regs.h
new file mode 100644
index 000000000000..86b996c702a0
--- /dev/null
+++ b/drivers/thunderbolt/nhi_regs.h
@@ -0,0 +1,101 @@
+/*
+ * Thunderbolt Cactus Ridge driver - NHI registers
+ *
+ * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
+ */
+
+#ifndef DSL3510_REGS_H_
+#define DSL3510_REGS_H_
+
+#include <linux/types.h>
+
+enum ring_flags {
+	RING_FLAG_ISOCH_ENABLE = 1 << 27, /* TX only? */
+	RING_FLAG_E2E_FLOW_CONTROL = 1 << 28,
+	RING_FLAG_PCI_NO_SNOOP = 1 << 29,
+	RING_FLAG_RAW = 1 << 30, /* ignore EOF/SOF mask, include checksum */
+	RING_FLAG_ENABLE = 1 << 31,
+};
+
+enum ring_desc_flags {
+	RING_DESC_ISOCH = 0x1, /* TX only? */
+	RING_DESC_COMPLETED = 0x2, /* set by NHI */
+	RING_DESC_POSTED = 0x4, /* always set this */
+	RING_DESC_INTERRUPT = 0x8, /* request an interrupt on completion */
+};
+
+/**
+ * struct ring_desc - TX/RX ring entry
+ *
+ * For TX set length/eof/sof.
+ * For RX length/eof/sof are set by the NHI.
+ */
+struct ring_desc {
+	u64 phys;
+	u32 length:12;
+	u32 eof:4;
+	u32 sof:4;
+	enum ring_desc_flags flags:12;
+	u32 time; /* write zero */
+} __packed;
+
+/* NHI registers in bar 0 */
+
+/*
+ * 16 bytes per entry, one entry for every hop (REG_HOP_COUNT)
+ * 00: physical pointer to an array of struct ring_desc
+ * 08: ring tail (set by NHI)
+ * 10: ring head (index of first non posted descriptor)
+ * 12: descriptor count
+ */
+#define REG_TX_RING_BASE	0x00000
+
+/*
+ * 16 bytes per entry, one entry for every hop (REG_HOP_COUNT)
+ * 00: physical pointer to an array of struct ring_desc
+ * 08: ring head (index of first not posted descriptor)
+ * 10: ring tail (set by NHI)
+ * 12: descriptor count
+ * 14: max frame sizes (anything larger than 0x100 has no effect)
+ */
+#define REG_RX_RING_BASE	0x08000
+
+/*
+ * 32 bytes per entry, one entry for every hop (REG_HOP_COUNT)
+ * 00: enum_ring_flags
+ * 04: isoch time stamp ?? (write 0)
+ * ..: unknown
+ */
+#define REG_TX_OPTIONS_BASE	0x19800
+
+/*
+ * 32 bytes per entry, one entry for every hop (REG_HOP_COUNT)
+ * 00: enum ring_flags
+ *     If RING_FLAG_E2E_FLOW_CONTROL is set then bits 13-23 must be set to
+ *     the corresponding TX hop id.
+ * 04: EOF/SOF mask (ignored for RING_FLAG_RAW rings)
+ * ..: unknown
+ */
+#define REG_RX_OPTIONS_BASE	0x29800
+
+/*
+ * three bitfields: tx, rx, rx overflow
+ * Every bitfield contains one bit for every hop (REG_HOP_COUNT). Registers are
+ * cleared on read. New interrupts are fired only after ALL registers have been
+ * read (even those containing only disabled rings).
+ */
+#define REG_RING_NOTIFY_BASE	0x37800
+#define RING_NOTIFY_REG_COUNT(nhi) ((31 + 3 * nhi->hop_count) / 32)
+
+/*
+ * two bitfields: rx, tx
+ * Both bitfields contains one bit for every hop (REG_HOP_COUNT). To
+ * enable/disable interrupts set/clear the corresponding bits.
+ */
+#define REG_RING_INTERRUPT_BASE	0x38200
+#define RING_INTERRUPT_REG_COUNT(nhi) ((31 + 2 * nhi->hop_count) / 32)
+
+/* The last 11 bits contain the number of hops supported by the NHI port. */
+#define REG_HOP_COUNT		0x39640
+
+#endif