From: Ben Wolsieffer <ben.wolsieffer@hefring.com>
Date: Thu, 2 Nov 2023 20:30:38 +0000 (-0400)
Subject: regmap: ram: support noinc semantics
X-Git-Tag: v6.8-rc1~173^2~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=02e3564a344064aca49f147e8a4eecbe5d3459fc;p=thirdparty%2Flinux.git

regmap: ram: support noinc semantics

Support noinc semantics in RAM backed regmaps, for testing purposes. Add
a new callback that selects registers which should have noinc behavior.
Bulk writes to a noinc register will cause the last value in the buffer
to be assigned to the register, while bulk reads will copy the same
value repeatedly into the buffer.

This patch only adds support to regmap-raw-ram, since regmap-ram does
not support bulk operations.

Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com>
Link: https://lore.kernel.org/r/20231102203039.3069305-1-ben.wolsieffer@hefring.com
Signed-off-by: Mark Brown <broonie@kernel.org>
---

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 9a9ea514c2d81..583dd5d7d46bf 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -318,6 +318,7 @@ struct regmap_ram_data {
 	bool *read;
 	bool *written;
 	enum regmap_endian reg_endian;
+	bool (*noinc_reg)(struct regmap_ram_data *data, unsigned int reg);
 };
 
 /*
diff --git a/drivers/base/regmap/regmap-raw-ram.c b/drivers/base/regmap/regmap-raw-ram.c
index c9b800885f3ba..463adafa9532c 100644
--- a/drivers/base/regmap/regmap-raw-ram.c
+++ b/drivers/base/regmap/regmap-raw-ram.c
@@ -41,10 +41,15 @@ static int regmap_raw_ram_gather_write(void *context,
 		return -EINVAL;
 
 	r = decode_reg(data->reg_endian, reg);
-	memcpy(&our_buf[r], val, val_len);
-
-	for (i = 0; i < val_len / 2; i++)
-		data->written[r + i] = true;
+	if (data->noinc_reg && data->noinc_reg(data, r)) {
+		memcpy(&our_buf[r], val + val_len - 2, 2);
+		data->written[r] = true;
+	} else {
+		memcpy(&our_buf[r], val, val_len);
+
+		for (i = 0; i < val_len / 2; i++)
+			data->written[r + i] = true;
+	}
 	
 	return 0;
 }
@@ -70,10 +75,16 @@ static int regmap_raw_ram_read(void *context,
 		return -EINVAL;
 
 	r = decode_reg(data->reg_endian, reg);
-	memcpy(val, &our_buf[r], val_len);
-
-	for (i = 0; i < val_len / 2; i++)
-		data->read[r + i] = true;
+	if (data->noinc_reg && data->noinc_reg(data, r)) {
+		for (i = 0; i < val_len; i += 2)
+			memcpy(val + i, &our_buf[r], 2);
+		data->read[r] = true;
+	} else {
+		memcpy(val, &our_buf[r], val_len);
+
+		for (i = 0; i < val_len / 2; i++)
+			data->read[r + i] = true;
+	}
 
 	return 0;
 }