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generic: backport regmap reg_base and downshift features
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coolsnowwolf committed Mar 13, 2023
1 parent 1a232d6 commit c9360b1
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Showing 4 changed files with 243 additions and 1 deletion.
Original file line number Diff line number Diff line change
@@ -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;

Original file line number Diff line number Diff line change
@@ -0,0 +1,95 @@
From 0074f3f2b1e43d3cedd97e47fb6980db6d2ba79e Mon Sep 17 00:00:00 2001
From: Colin Foster <colin.foster@in-advantage.com>
Date: Sun, 13 Mar 2022 15:45:24 -0700
Subject: [PATCH 2/2] regmap: allow a defined reg_base to be added to every
address

There's an inconsistency that arises when a register set can be accessed
internally via MMIO, or externally via SPI. The VSC7514 chip allows both
modes of operation. When internally accessed, the system utilizes __iomem,
devm_ioremap_resource, and devm_regmap_init_mmio.

For SPI it isn't possible to utilize memory-mapped IO. To properly operate,
the resource base must be added to the register before every operation.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/20220313224524.399947-3-colin.foster@in-advantage.com
Signed-off-by: Mark Brown <broonie@kernel.org>
---
drivers/base/regmap/internal.h | 1 +
drivers/base/regmap/regmap.c | 6 ++++++
include/linux/regmap.h | 3 +++
3 files changed, 10 insertions(+)

--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -63,6 +63,7 @@ struct regmap {
regmap_unlock unlock;
void *lock_arg; /* This is passed to lock/unlock functions */
gfp_t alloc_flags;
+ unsigned int reg_base;

struct device *dev; /* Device we do I/O on */
void *work_buf; /* Scratch buffer used to format I/O */
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -821,6 +821,8 @@ struct regmap *__regmap_init(struct devi
else
map->alloc_flags = GFP_KERNEL;

+ map->reg_base = config->reg_base;
+
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;
@@ -1736,6 +1738,7 @@ static int _regmap_raw_write_impl(struct
return ret;
}

+ reg += map->reg_base;
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,
@@ -1907,6 +1910,7 @@ static int _regmap_bus_formatted_write(v
return ret;
}

+ reg += map->reg_base;
reg >>= map->format.reg_downshift;
map->format.format_write(map, reg, val);

@@ -2349,6 +2353,7 @@ 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->reg_base;
reg >>= map->format.reg_downshift;
map->format.format_reg(u8, reg, map->reg_shift);
u8 += reg_bytes + pad_bytes;
@@ -2677,6 +2682,7 @@ static int _regmap_raw_read(struct regma
return ret;
}

+ reg += map->reg_base;
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,
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -239,6 +239,8 @@ typedef void (*regmap_unlock)(void *);
* used.
* @reg_downshift: The number of bits to downshift the register before
* performing any operations.
+ * @reg_base: Value to be added to every register address before performing any
+ * operation.
* @pad_bits: Number of bits of padding between register and value.
* @val_bits: Number of bits in a register value, mandatory.
*
@@ -363,6 +365,7 @@ struct regmap_config {
int reg_bits;
int reg_stride;
int reg_downshift;
+ unsigned int reg_base;
int pad_bits;
int val_bits;

Original file line number Diff line number Diff line change
@@ -0,0 +1,57 @@
From 697c3892d825fb78f42ec8e53bed065dd728db3e Mon Sep 17 00:00:00 2001
From: Daniel Golle <daniel@makrotopia.org>
Date: Mon, 30 Jan 2023 02:04:57 +0000
Subject: [PATCH] regmap: apply reg_base and reg_downshift for single register
ops

reg_base and reg_downshift currently don't have any effect if used with
a regmap_bus or regmap_config which only offers single register
operations (ie. reg_read, reg_write and optionally reg_update_bits).

Fix that and take them into account also for regmap_bus with only
reg_read and read_write operations by applying reg_base and
reg_downshift in _regmap_bus_reg_write, _regmap_bus_reg_read.

Also apply reg_base and reg_downshift in _regmap_update_bits, but only
in case the operation is carried out with a reg_update_bits call
defined in either regmap_bus or regmap_config.

Fixes: 0074f3f2b1e43d ("regmap: allow a defined reg_base to be added to every address")
Fixes: 86fc59ef818beb ("regmap: add configurable downshift for addresses")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Tested-by: Colin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/Y9clyVS3tQEHlUhA@makrotopia.org
Signed-off-by: Mark Brown <broonie@kernel.org>
---
drivers/base/regmap/regmap.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1929,6 +1929,8 @@ static int _regmap_bus_reg_write(void *c
{
struct regmap *map = context;

+ reg += map->reg_base;
+ reg >>= map->format.reg_downshift;
return map->bus->reg_write(map->bus_context, reg, val);
}

@@ -2703,6 +2705,8 @@ static int _regmap_bus_reg_read(void *co
{
struct regmap *map = context;

+ reg += map->reg_base;
+ reg >>= map->format.reg_downshift;
return map->bus->reg_read(map->bus_context, reg, val);
}

@@ -3078,6 +3082,8 @@ static int _regmap_update_bits(struct re
*change = false;

if (regmap_volatile(map, reg) && map->reg_update_bits) {
+ reg += map->reg_base;
+ reg >>= map->format.reg_downshift;
ret = map->reg_update_bits(map->bus_context, reg, mask, val);
if (ret == 0 && change)
*change = true;
2 changes: 1 addition & 1 deletion target/linux/generic/hack-5.15/259-regmap_dynamic.patch
Original file line number Diff line number Diff line change
Expand Up @@ -125,7 +125,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/property.h>
@@ -3341,3 +3342,5 @@ static int __init regmap_initcall(void)
@@ -3358,3 +3359,5 @@ static int __init regmap_initcall(void)
return 0;
}
postcore_initcall(regmap_initcall);
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