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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;
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