net: ipa: introduce ipa_reg()

Create a new function that returns a register descriptor given its
ID.  Change ipa_reg_offset() and ipa_reg_n_offset() so they take a
register descriptor argument rather than an IPA pointer and register
ID.  Have them accept null pointers (and return an invalid 0 offset),
to avoid the need for excessive error checking.  (A warning is issued
whenever ipa_reg() returns 0).

Call ipa_reg() or ipa_reg_n() to look up information about the
register before calls to ipa_reg_offset() and ipa_reg_n_offset().
Delay looking up offsets until they're needed to read or write
registers.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 3 insertions, 8 deletions

diff --git a/drivers/net/ipa/ipa_reg.c b/drivers/net/ipa/ipa_reg.c
index 67c01c6973ff..fb4663bcf14b 100644
--- a/drivers/net/ipa/ipa_reg.c
+++ b/drivers/net/ipa/ipa_reg.c
@@ -67,17 +67,12 @@ static bool ipa_reg_valid(struct ipa *ipa, enum ipa_reg_id reg_id)
 	return valid && ipa->regs->reg[reg_id];
 }
 
-/* Assumes the endpoint transfer direction is valid; 0 is a bad offset */
-u32 __ipa_reg_offset(struct ipa *ipa, enum ipa_reg_id reg_id, u32 n)
+const struct ipa_reg *ipa_reg(struct ipa *ipa, enum ipa_reg_id reg_id)
 {
-	const struct ipa_reg *reg;
-
 	if (WARN_ON(!ipa_reg_valid(ipa, reg_id)))
-		return 0;
-
-	reg = ipa->regs->reg[reg_id];
+		return NULL;
 
-	return reg->offset + n * reg->stride;
+	return ipa->regs->reg[reg_id];
 }
 
 static const struct ipa_regs *ipa_regs(enum ipa_version version)