[PATCH v2 3/4] regmap: mmio: Introduce IO accessors that can talk to IO port

From: Andy Shevchenko
Date: Mon Aug 08 2022 - 16:34:30 EST


Some users may use regmap MMIO for IO ports, and this can be done
by assigning ioreadXX()/iowriteXX() and their Big Endian counterparts
to the regmap context.

Add IO port support with a corresponding flag added.

While doing that, make sure that user won't select relaxed MMIO access
along with IO port because the latter have no relaxed variants.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/base/regmap/regmap-mmio.c | 105 +++++++++++++++++++++++++++---
include/linux/regmap.h | 3 +
2 files changed, 99 insertions(+), 9 deletions(-)

diff --git a/drivers/base/regmap/regmap-mmio.c b/drivers/base/regmap/regmap-mmio.c
index b1bd93ea405e..37f79e912d01 100644
--- a/drivers/base/regmap/regmap-mmio.c
+++ b/drivers/base/regmap/regmap-mmio.c
@@ -74,6 +74,12 @@ static void regmap_mmio_write8_relaxed(struct regmap_mmio_context *ctx,
writeb_relaxed(val, ctx->regs + reg);
}

+static void regmap_mmio_iowrite8(struct regmap_mmio_context *ctx,
+ unsigned int reg, unsigned int val)
+{
+ iowrite8(val, ctx->regs + reg);
+}
+
static void regmap_mmio_write16le(struct regmap_mmio_context *ctx,
unsigned int reg,
unsigned int val)
@@ -88,6 +94,12 @@ static void regmap_mmio_write16le_relaxed(struct regmap_mmio_context *ctx,
writew_relaxed(val, ctx->regs + reg);
}

+static void regmap_mmio_iowrite16le(struct regmap_mmio_context *ctx,
+ unsigned int reg, unsigned int val)
+{
+ iowrite16(val, ctx->regs + reg);
+}
+
static void regmap_mmio_write16be(struct regmap_mmio_context *ctx,
unsigned int reg,
unsigned int val)
@@ -95,6 +107,12 @@ static void regmap_mmio_write16be(struct regmap_mmio_context *ctx,
iowrite16be(val, ctx->regs + reg);
}

+static void regmap_mmio_iowrite16be(struct regmap_mmio_context *ctx,
+ unsigned int reg, unsigned int val)
+{
+ iowrite16be(val, ctx->regs + reg);
+}
+
static void regmap_mmio_write32le(struct regmap_mmio_context *ctx,
unsigned int reg,
unsigned int val)
@@ -109,6 +127,12 @@ static void regmap_mmio_write32le_relaxed(struct regmap_mmio_context *ctx,
writel_relaxed(val, ctx->regs + reg);
}

+static void regmap_mmio_iowrite32le(struct regmap_mmio_context *ctx,
+ unsigned int reg, unsigned int val)
+{
+ iowrite32(val, ctx->regs + reg);
+}
+
static void regmap_mmio_write32be(struct regmap_mmio_context *ctx,
unsigned int reg,
unsigned int val)
@@ -116,6 +140,12 @@ static void regmap_mmio_write32be(struct regmap_mmio_context *ctx,
iowrite32be(val, ctx->regs + reg);
}

+static void regmap_mmio_iowrite32be(struct regmap_mmio_context *ctx,
+ unsigned int reg, unsigned int val)
+{
+ iowrite32be(val, ctx->regs + reg);
+}
+
static int regmap_mmio_write(void *context, unsigned int reg, unsigned int val)
{
struct regmap_mmio_context *ctx = context;
@@ -147,6 +177,12 @@ static unsigned int regmap_mmio_read8_relaxed(struct regmap_mmio_context *ctx,
return readb_relaxed(ctx->regs + reg);
}

+static unsigned int regmap_mmio_ioread8(struct regmap_mmio_context *ctx,
+ unsigned int reg)
+{
+ return ioread8(ctx->regs + reg);
+}
+
static unsigned int regmap_mmio_read16le(struct regmap_mmio_context *ctx,
unsigned int reg)
{
@@ -159,12 +195,24 @@ static unsigned int regmap_mmio_read16le_relaxed(struct regmap_mmio_context *ctx
return readw_relaxed(ctx->regs + reg);
}

+static unsigned int regmap_mmio_ioread16le(struct regmap_mmio_context *ctx,
+ unsigned int reg)
+{
+ return ioread16(ctx->regs + reg);
+}
+
static unsigned int regmap_mmio_read16be(struct regmap_mmio_context *ctx,
unsigned int reg)
{
return ioread16be(ctx->regs + reg);
}

+static unsigned int regmap_mmio_ioread16be(struct regmap_mmio_context *ctx,
+ unsigned int reg)
+{
+ return ioread16be(ctx->regs + reg);
+}
+
static unsigned int regmap_mmio_read32le(struct regmap_mmio_context *ctx,
unsigned int reg)
{
@@ -177,12 +225,24 @@ static unsigned int regmap_mmio_read32le_relaxed(struct regmap_mmio_context *ctx
return readl_relaxed(ctx->regs + reg);
}

+static unsigned int regmap_mmio_ioread32le(struct regmap_mmio_context *ctx,
+ unsigned int reg)
+{
+ return ioread32(ctx->regs + reg);
+}
+
static unsigned int regmap_mmio_read32be(struct regmap_mmio_context *ctx,
unsigned int reg)
{
return ioread32be(ctx->regs + reg);
}

+static unsigned int regmap_mmio_ioread32be(struct regmap_mmio_context *ctx,
+ unsigned int reg)
+{
+ return ioread32be(ctx->regs + reg);
+}
+
static int regmap_mmio_read(void *context, unsigned int reg, unsigned int *val)
{
struct regmap_mmio_context *ctx = context;
@@ -245,6 +305,9 @@ static struct regmap_mmio_context *regmap_mmio_gen_context(struct device *dev,
if (config->reg_stride < min_stride)
return ERR_PTR(-EINVAL);

+ if (config->use_relaxed_mmio && config->io_port)
+ return ERR_PTR(-EINVAL);
+
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return ERR_PTR(-ENOMEM);
@@ -261,7 +324,10 @@ static struct regmap_mmio_context *regmap_mmio_gen_context(struct device *dev,
#endif
switch (config->val_bits) {
case 8:
- if (config->use_relaxed_mmio) {
+ if (config->io_port) {
+ ctx->reg_read = regmap_mmio_ioread8;
+ ctx->reg_write = regmap_mmio_iowrite8;
+ } else if (config->use_relaxed_mmio) {
ctx->reg_read = regmap_mmio_read8_relaxed;
ctx->reg_write = regmap_mmio_write8_relaxed;
} else {
@@ -270,7 +336,10 @@ static struct regmap_mmio_context *regmap_mmio_gen_context(struct device *dev,
}
break;
case 16:
- if (config->use_relaxed_mmio) {
+ if (config->io_port) {
+ ctx->reg_read = regmap_mmio_ioread16le;
+ ctx->reg_write = regmap_mmio_iowrite16le;
+ } else if (config->use_relaxed_mmio) {
ctx->reg_read = regmap_mmio_read16le_relaxed;
ctx->reg_write = regmap_mmio_write16le_relaxed;
} else {
@@ -279,7 +348,10 @@ static struct regmap_mmio_context *regmap_mmio_gen_context(struct device *dev,
}
break;
case 32:
- if (config->use_relaxed_mmio) {
+ if (config->io_port) {
+ ctx->reg_read = regmap_mmio_ioread32le;
+ ctx->reg_write = regmap_mmio_iowrite32le;
+ } else if (config->use_relaxed_mmio) {
ctx->reg_read = regmap_mmio_read32le_relaxed;
ctx->reg_write = regmap_mmio_write32le_relaxed;
} else {
@@ -298,16 +370,31 @@ static struct regmap_mmio_context *regmap_mmio_gen_context(struct device *dev,
#endif
switch (config->val_bits) {
case 8:
- ctx->reg_read = regmap_mmio_read8;
- ctx->reg_write = regmap_mmio_write8;
+ if (config->io_port) {
+ ctx->reg_read = regmap_mmio_ioread8;
+ ctx->reg_write = regmap_mmio_iowrite8;
+ } else {
+ ctx->reg_read = regmap_mmio_read8;
+ ctx->reg_write = regmap_mmio_write8;
+ }
break;
case 16:
- ctx->reg_read = regmap_mmio_read16be;
- ctx->reg_write = regmap_mmio_write16be;
+ if (config->io_port) {
+ ctx->reg_read = regmap_mmio_ioread16be;
+ ctx->reg_write = regmap_mmio_iowrite16be;
+ } else {
+ ctx->reg_read = regmap_mmio_read16be;
+ ctx->reg_write = regmap_mmio_write16be;
+ }
break;
case 32:
- ctx->reg_read = regmap_mmio_read32be;
- ctx->reg_write = regmap_mmio_write32be;
+ if (config->io_port) {
+ ctx->reg_read = regmap_mmio_ioread32be;
+ ctx->reg_write = regmap_mmio_iowrite32be;
+ } else {
+ ctx->reg_read = regmap_mmio_read32be;
+ ctx->reg_write = regmap_mmio_write32be;
+ }
break;
default:
ret = -EINVAL;
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 7cf2157134ac..8cccc247cd37 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -311,6 +311,8 @@ typedef void (*regmap_unlock)(void *);
* This field is a duplicate of a similar file in
* 'struct regmap_bus' and serves exact same purpose.
* Use it only for "no-bus" cases.
+ * @io_port: Support IO port accessors. Makes sense only when MMIO vs. IO port
+ * access can be distinguished.
* @max_register: Optional, specifies the maximum valid register address.
* @wr_table: Optional, points to a struct regmap_access_table specifying
* valid ranges for write access.
@@ -399,6 +401,7 @@ struct regmap_config {
size_t max_raw_write;

bool fast_io;
+ bool io_port;

unsigned int max_register;
const struct regmap_access_table *wr_table;
--
2.35.1