[PATCH 2/2] regmap: sdw: Remove 8-bit value size restriction

From: Charles Keepax
Date: Thu Jan 12 2023 - 13:00:12 EST


From: Lucas Tanure <tanureal@xxxxxxxxxxxxxxxxxxxxx>

Some SoundWire devices have larger width device specific register
maps, in addition to the standard SoundWire 8-bit map. Update the
helpers to allow accessing arbitrarily sized register values and remove
the explicit 8-bit restriction from regmap_sdw_config_check.

Signed-off-by: Lucas Tanure <tanureal@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
---

This patch requires the patch commit 62dc9f3f2fd0 ("soundwire: bus:
export sdw_nwrite_no_pm and sdw_nread_no_pm functions") from Vinod's
SoundWire tree to build, so not sure if we want to push these patches
through his tree or merge his tree across.

drivers/base/regmap/regmap-sdw.c | 39 ++++++++++++++++++++------------
1 file changed, 24 insertions(+), 15 deletions(-)

diff --git a/drivers/base/regmap/regmap-sdw.c b/drivers/base/regmap/regmap-sdw.c
index 95801fd411b26..09899ae99fc19 100644
--- a/drivers/base/regmap/regmap-sdw.c
+++ b/drivers/base/regmap/regmap-sdw.c
@@ -6,43 +6,52 @@
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/soundwire/sdw.h>
+#include <linux/types.h>
#include "internal.h"

-static int regmap_sdw_write(void *context, unsigned int reg, unsigned int val)
+static int regmap_sdw_write(void *context, const void *val_buf, size_t val_size)
{
struct device *dev = context;
struct sdw_slave *slave = dev_to_sdw_dev(dev);
+ /* First word of buffer contains the destination address */
+ u32 addr = le32_to_cpu(*(const __le32 *)val_buf);
+ const u8 *val = val_buf;

- return sdw_write_no_pm(slave, reg, val);
+ return sdw_nwrite_no_pm(slave, addr, val_size - sizeof(addr), val + sizeof(addr));
}

-static int regmap_sdw_read(void *context, unsigned int reg, unsigned int *val)
+static int regmap_sdw_gather_write(void *context,
+ const void *reg_buf, size_t reg_size,
+ const void *val_buf, size_t val_size)
{
struct device *dev = context;
struct sdw_slave *slave = dev_to_sdw_dev(dev);
- int read;
+ u32 addr = le32_to_cpu(*(const __le32 *)reg_buf);

- read = sdw_read_no_pm(slave, reg);
- if (read < 0)
- return read;
+ return sdw_nwrite_no_pm(slave, addr, val_size, val_buf);
+}

- *val = read;
- return 0;
+static int regmap_sdw_read(void *context,
+ const void *reg_buf, size_t reg_size,
+ void *val_buf, size_t val_size)
+{
+ struct device *dev = context;
+ struct sdw_slave *slave = dev_to_sdw_dev(dev);
+ u32 addr = le32_to_cpu(*(const __le32 *)reg_buf);
+
+ return sdw_nread_no_pm(slave, addr, val_size, val_buf);
}

static const struct regmap_bus regmap_sdw = {
- .reg_read = regmap_sdw_read,
- .reg_write = regmap_sdw_write,
+ .write = regmap_sdw_write,
+ .gather_write = regmap_sdw_gather_write,
+ .read = regmap_sdw_read,
.reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
.val_format_endian_default = REGMAP_ENDIAN_LITTLE,
};

static int regmap_sdw_config_check(const struct regmap_config *config)
{
- /* All register are 8-bits wide as per MIPI Soundwire 1.0 Spec */
- if (config->val_bits != 8)
- return -ENOTSUPP;
-
/* Register addresses are 32 bits wide */
if (config->reg_bits != 32)
return -ENOTSUPP;
--
2.30.2