[PATCH v6 07/14] regmap: Add SoundWire bus support

From: Vinod Koul
Date: Thu Dec 14 2017 - 00:48:12 EST

SoundWire bus provides sdw_read() and sdw_write() APIs for Slave
devices to program the registers. Provide support in regmap for
SoundWire bus.

Signed-off-by: Hardik T Shah <hardik.t.shah@xxxxxxxxx>
Signed-off-by: Sanyog Kale <sanyog.r.kale@xxxxxxxxx>
Reviewed-by: Philippe Ombredanne <pombredanne@xxxxxxxx>
Acked-By: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Reviewed-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
---
drivers/base/regmap/Kconfig | 4 ++
drivers/base/regmap/Makefile | 1 +
drivers/base/regmap/regmap-sdw.c | 92 ++++++++++++++++++++++++++++++++++++++++
drivers/soundwire/Kconfig | 1 +
include/linux/regmap.h | 37 ++++++++++++++++
5 files changed, 135 insertions(+)
create mode 100644 drivers/base/regmap/regmap-sdw.c

diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
index 3a1535d812d8..71dc88a48cfa 100644
--- a/drivers/base/regmap/Kconfig
+++ b/drivers/base/regmap/Kconfig
@@ -41,3 +41,7 @@ config REGMAP_IRQ

config REGMAP_HWSPINLOCK
bool
+
+config REGMAP_SOUNDWIRE
+ tristate
+ depends on SOUNDWIRE_BUS
diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile
index 0d298c446108..22d263cca395 100644
--- a/drivers/base/regmap/Makefile
+++ b/drivers/base/regmap/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_REGMAP_SPMI) += regmap-spmi.o
obj-$(CONFIG_REGMAP_MMIO) += regmap-mmio.o
obj-$(CONFIG_REGMAP_IRQ) += regmap-irq.o
obj-$(CONFIG_REGMAP_W1) += regmap-w1.o
+obj-$(CONFIG_REGMAP_SOUNDWIRE) += regmap-sdw.o
diff --git a/drivers/base/regmap/regmap-sdw.c b/drivers/base/regmap/regmap-sdw.c
new file mode 100644
index 000000000000..3a72039e94ea
--- /dev/null
+++ b/drivers/base/regmap/regmap-sdw.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright(c) 2015-17 Intel Corporation.
+
+#include <linux/device.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/soundwire/sdw.h>
+#include "internal.h"
+
+static int regmap_sdw_write(void *context, unsigned int reg, unsigned int val)
+{
+ struct device *dev = context;
+ struct sdw_slave *slave = dev_to_sdw_dev(dev);
+
+ return sdw_write(slave, reg, val);
+}
+
+static int regmap_sdw_read(void *context, unsigned int reg, unsigned int *val)
+{
+ struct device *dev = context;
+ struct sdw_slave *slave = dev_to_sdw_dev(dev);
+ int read;
+
+ read = sdw_read(slave, reg);
+ if (read < 0)
+ return read;
+
+ *val = read;
+ return 0;
+}
+
+static struct regmap_bus regmap_sdw = {
+ .reg_read = regmap_sdw_read,
+ .reg_write = regmap_sdw_write,
+ .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;
+
+ /* Registers are 32 bits wide */
+ if (config->reg_bits != 32)
+ return -ENOTSUPP;
+
+ /* SoundWire register address are contiguous */
+ if (config->reg_stride != 0)
+ return -ENOTSUPP;
+
+ if (config->pad_bits != 0)
+ return -ENOTSUPP;
+
+ return 0;
+}
+
+struct regmap *__regmap_init_sdw(struct sdw_slave *sdw,
+ const struct regmap_config *config,
+ struct lock_class_key *lock_key,
+ const char *lock_name)
+{
+ int ret;
+
+ ret = regmap_sdw_config_check(config);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return __regmap_init(&sdw->dev, &regmap_sdw,
+ &sdw->dev, config, lock_key, lock_name);
+}
+EXPORT_SYMBOL_GPL(__regmap_init_sdw);
+
+struct regmap *__devm_regmap_init_sdw(struct sdw_slave *sdw,
+ const struct regmap_config *config,
+ struct lock_class_key *lock_key,
+ const char *lock_name)
+{
+ int ret;
+
+ ret = regmap_sdw_config_check(config);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return __devm_regmap_init(&sdw->dev, &regmap_sdw,
+ &sdw->dev, config, lock_key, lock_name);
+}
+EXPORT_SYMBOL_GPL(__devm_regmap_init_sdw);
+
+MODULE_DESCRIPTION("Regmap SoundWire Module");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/soundwire/Kconfig b/drivers/soundwire/Kconfig
index d7d3908f4913..92a2c3bad87f 100644
--- a/drivers/soundwire/Kconfig
+++ b/drivers/soundwire/Kconfig
@@ -18,5 +18,6 @@ comment "SoundWire Devices"

config SOUNDWIRE_BUS
tristate
+ select REGMAP_SOUNDWIRE

endif
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 15eddc1353ba..97a9c6563bb1 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -30,6 +30,7 @@ struct regmap;
struct regmap_range_cfg;
struct regmap_field;
struct snd_ac97;
+struct sdw_slave;

/* An enum of all the supported cache types */
enum regcache_type {
@@ -524,6 +525,10 @@ struct regmap *__regmap_init_ac97(struct snd_ac97 *ac97,
const struct regmap_config *config,
struct lock_class_key *lock_key,
const char *lock_name);
+struct regmap *__regmap_init_sdw(struct sdw_slave *sdw,
+ const struct regmap_config *config,
+ struct lock_class_key *lock_key,
+ const char *lock_name);

struct regmap *__devm_regmap_init(struct device *dev,
const struct regmap_bus *bus,
@@ -561,6 +566,10 @@ struct regmap *__devm_regmap_init_ac97(struct snd_ac97 *ac97,
const struct regmap_config *config,
struct lock_class_key *lock_key,
const char *lock_name);
+struct regmap *__devm_regmap_init_sdw(struct sdw_slave *sdw,
+ const struct regmap_config *config,
+ struct lock_class_key *lock_key,
+ const char *lock_name);

/*
* Wrapper for regmap_init macros to include a unique lockdep key and name
@@ -710,6 +719,20 @@ int regmap_attach_dev(struct device *dev, struct regmap *map,
bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg);

/**
+ * regmap_init_sdw() - Initialise register map
+ *
+ * @sdw: Device that will be interacted with
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer to
+ * a struct regmap.
+ */
+#define regmap_init_sdw(sdw, config) \
+ __regmap_lockdep_wrapper(__regmap_init_sdw, #config, \
+ sdw, config)
+
+
+/**
* devm_regmap_init() - Initialise managed register map
*
* @dev: Device that will be interacted with
@@ -839,6 +862,20 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg);
__regmap_lockdep_wrapper(__devm_regmap_init_ac97, #config, \
ac97, config)

+/**
+ * devm_regmap_init_sdw() - Initialise managed register map
+ *
+ * @sdw: Device that will be interacted with
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer
+ * to a struct regmap. The regmap will be automatically freed by the
+ * device management code.
+ */
+#define devm_regmap_init_sdw(sdw, config) \
+ __regmap_lockdep_wrapper(__devm_regmap_init_sdw, #config, \
+ sdw, config)
+
void regmap_exit(struct regmap *map);
int regmap_reinit_cache(struct regmap *map,
const struct regmap_config *config);
--
2.7.4