generic: backport regmap reg_base and downshift features

Backport new regmap features from Linux 5.18 which are needed to let
mt7530 use pcs-mtk-lynxi.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

1 files changed, 90 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.15/350-v5.18-regmap-add-configurable-downshift-for-addresses.patch b/target/linux/generic/backport-5.15/350-v5.18-regmap-add-configurable-downshift-for-addresses.patch
new file mode 100644
index 0000000000..99cd89ea00
--- /dev/null
+++ b/target/linux/generic/backport-5.15/350-v5.18-regmap-add-configurable-downshift-for-addresses.patch
@@ -0,0 +1,90 @@
+From 86fc59ef818beb0e1945d17f8e734898baba7e4e Mon Sep 17 00:00:00 2001
+From: Colin Foster <colin.foster@in-advantage.com>
+Date: Sun, 13 Mar 2022 15:45:23 -0700
+Subject: [PATCH 1/2] regmap: add configurable downshift for addresses
+
+Add an additional reg_downshift to be applied to register addresses before
+any register accesses. An example of a device that uses this is a VSC7514
+chip, which require each register address to be downshifted by two if the
+access is performed over a SPI bus.
+
+Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
+Link: https://lore.kernel.org/r/20220313224524.399947-2-colin.foster@in-advantage.com
+Signed-off-by: Mark Brown <broonie@kernel.org>
+---
+ drivers/base/regmap/internal.h | 1 +
+ drivers/base/regmap/regmap.c   | 5 +++++
+ include/linux/regmap.h         | 3 +++
+ 3 files changed, 9 insertions(+)
+
+--- a/drivers/base/regmap/internal.h
++++ b/drivers/base/regmap/internal.h
+@@ -31,6 +31,7 @@ struct regmap_format {
+ 	size_t buf_size;
+ 	size_t reg_bytes;
+ 	size_t pad_bytes;
++	size_t reg_downshift;
+ 	size_t val_bytes;
+ 	void (*format_write)(struct regmap *map,
+ 			     unsigned int reg, unsigned int val);
+--- a/drivers/base/regmap/regmap.c
++++ b/drivers/base/regmap/regmap.c
+@@ -823,6 +823,7 @@ struct regmap *__regmap_init(struct devi
+ 
+ 	map->format.reg_bytes = DIV_ROUND_UP(config->reg_bits, 8);
+ 	map->format.pad_bytes = config->pad_bits / 8;
++	map->format.reg_downshift = config->reg_downshift;
+ 	map->format.val_bytes = DIV_ROUND_UP(config->val_bits, 8);
+ 	map->format.buf_size = DIV_ROUND_UP(config->reg_bits +
+ 			config->val_bits + config->pad_bits, 8);
+@@ -1735,6 +1736,7 @@ static int _regmap_raw_write_impl(struct
+ 			return ret;
+ 	}
+ 
++	reg >>= map->format.reg_downshift;
+ 	map->format.format_reg(map->work_buf, reg, map->reg_shift);
+ 	regmap_set_work_buf_flag_mask(map, map->format.reg_bytes,
+ 				      map->write_flag_mask);
+@@ -1905,6 +1907,7 @@ static int _regmap_bus_formatted_write(v
+ 			return ret;
+ 	}
+ 
++	reg >>= map->format.reg_downshift;
+ 	map->format.format_write(map, reg, val);
+ 
+ 	trace_regmap_hw_write_start(map, reg, 1);
+@@ -2346,6 +2349,7 @@ static int _regmap_raw_multi_reg_write(s
+ 		unsigned int reg = regs[i].reg;
+ 		unsigned int val = regs[i].def;
+ 		trace_regmap_hw_write_start(map, reg, 1);
++		reg >>= map->format.reg_downshift;
+ 		map->format.format_reg(u8, reg, map->reg_shift);
+ 		u8 += reg_bytes + pad_bytes;
+ 		map->format.format_val(u8, val, 0);
+@@ -2673,6 +2677,7 @@ static int _regmap_raw_read(struct regma
+ 			return ret;
+ 	}
+ 
++	reg >>= map->format.reg_downshift;
+ 	map->format.format_reg(map->work_buf, reg, map->reg_shift);
+ 	regmap_set_work_buf_flag_mask(map, map->format.reg_bytes,
+ 				      map->read_flag_mask);
+--- a/include/linux/regmap.h
++++ b/include/linux/regmap.h
+@@ -237,6 +237,8 @@ typedef void (*regmap_unlock)(void *);
+  * @reg_stride: The register address stride. Valid register addresses are a
+  *              multiple of this value. If set to 0, a value of 1 will be
+  *              used.
++ * @reg_downshift: The number of bits to downshift the register before
++ *		   performing any operations.
+  * @pad_bits: Number of bits of padding between register and value.
+  * @val_bits: Number of bits in a register value, mandatory.
+  *
+@@ -360,6 +362,7 @@ struct regmap_config {
+ 
+ 	int reg_bits;
+ 	int reg_stride;
++	int reg_downshift;
+ 	int pad_bits;
+ 	int val_bits;
+