[PATCH v2 13/22] thunderbolt: Add ring register accessors to tb_nhi_ops

[Sven Peter]

The ring descriptor and options registers are laid out differently on
the Apple NHI. Add optional tb_nhi_ops hooks for their base addresses
which fall back to the standard USB4 register layout when they are not
set.

Signed-off-by: Sven Peter <sven at kernel.org>
---
 drivers/thunderbolt/nhi.c | 32 ++++++++++++++++++++++++++------
 drivers/thunderbolt/nhi.h |  6 ++++++
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index fc54ff7edfb9..1b1e4a12c744 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -179,19 +179,37 @@ void nhi_disable_interrupts(struct tb_nhi *nhi)
 static void __iomem *ring_desc_base(struct tb_ring *ring)
 {
 	void __iomem *io = ring->nhi->iobase;
+
 	io += ring->is_tx ? REG_TX_RING_BASE : REG_RX_RING_BASE;
 	io += ring->hop * 16;
 	return io;
 }
 
+static void __iomem *nhi_ring_desc_base(struct tb_ring *ring)
+{
+	if (ring->nhi->ops->ring_desc_base)
+		return ring->nhi->ops->ring_desc_base(ring);
+
+	return ring_desc_base(ring);
+}
+
 static void __iomem *ring_options_base(struct tb_ring *ring)
 {
 	void __iomem *io = ring->nhi->iobase;
+
 	io += ring->is_tx ? REG_TX_OPTIONS_BASE : REG_RX_OPTIONS_BASE;
 	io += ring->hop * 32;
 	return io;
 }
 
+static void __iomem *nhi_ring_options_base(struct tb_ring *ring)
+{
+	if (ring->nhi->ops->ring_options_base)
+		return ring->nhi->ops->ring_options_base(ring);
+
+	return ring_options_base(ring);
+}
+
 static void ring_iowrite_cons(struct tb_ring *ring, u16 cons)
 {
 	/*
@@ -199,29 +217,31 @@ static void ring_iowrite_cons(struct tb_ring *ring, u16 cons)
 	 * are ignored by the hardware so we can save one ioread32() by
 	 * filling the read-only bits with zeroes.
 	 */
-	iowrite32(cons, ring_desc_base(ring) + 8);
+	iowrite32(cons, nhi_ring_desc_base(ring) + 8);
 }
 
 static void ring_iowrite_prod(struct tb_ring *ring, u16 prod)
 {
 	/* See ring_iowrite_cons() above for explanation */
-	iowrite32(prod << 16, ring_desc_base(ring) + 8);
+	iowrite32(prod << 16, nhi_ring_desc_base(ring) + 8);
 }
 
 static void ring_iowrite32desc(struct tb_ring *ring, u32 value, u32 offset)
 {
-	iowrite32(value, ring_desc_base(ring) + offset);
+	iowrite32(value, nhi_ring_desc_base(ring) + offset);
 }
 
 static void ring_iowrite64desc(struct tb_ring *ring, u64 value, u32 offset)
 {
-	iowrite32(value, ring_desc_base(ring) + offset);
-	iowrite32(value >> 32, ring_desc_base(ring) + offset + 4);
+	void __iomem *base = nhi_ring_desc_base(ring);
+
+	iowrite32(value, base + offset);
+	iowrite32(value >> 32, base + offset + 4);
 }
 
 static void ring_iowrite32options(struct tb_ring *ring, u32 value, u32 offset)
 {
-	iowrite32(value, ring_options_base(ring) + offset);
+	iowrite32(value, nhi_ring_options_base(ring) + offset);
 }
 
 static bool ring_full(struct tb_ring *ring)
diff --git a/drivers/thunderbolt/nhi.h b/drivers/thunderbolt/nhi.h
index 4884c3f5a2b2..3a963b0b5b46 100644
--- a/drivers/thunderbolt/nhi.h
+++ b/drivers/thunderbolt/nhi.h
@@ -52,6 +52,10 @@ extern const struct dev_pm_ops nhi_pm_ops;
  * @post_nvm_auth: hook to run after Thunderbolt 3 NVM authentication
  * @request_ring_irq: NHI specific interrupt retrieval hook
  * @release_ring_irq: NHI specific interrupt release hook
+ * @ring_desc_base: NHI specific hook returning the ring descriptor registers.
+ *		    If not set the standard USB4 NHI registers are used.
+ * @ring_options_base: NHI specific hook returning the ring option registers.
+ *		       If not set the standard USB4 NHI registers are used.
  * @ring_interrupt_active: NHI specific hook to activate/deactivate the
  *			   interrupt of a single ring. If not set the
  *			   standard USB4 NHI registers are used.
@@ -70,6 +74,8 @@ struct tb_nhi_ops {
 	void (*post_nvm_auth)(struct tb_nhi *nhi);
 	int (*request_ring_irq)(struct tb_ring *ring, bool no_suspend);
 	void (*release_ring_irq)(struct tb_ring *ring);
+	void __iomem *(*ring_desc_base)(struct tb_ring *ring);
+	void __iomem *(*ring_options_base)(struct tb_ring *ring);
 	void (*ring_interrupt_active)(struct tb_ring *ring, bool active);
 	bool (*is_present)(struct tb_nhi *nhi);
 	int (*init_interrupts)(struct tb_nhi *nhi);

-- 
2.55.0