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-rw-r--r--drivers/base/regmap/regmap-spi.c168
1 files changed, 168 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap-spi.c b/drivers/base/regmap/regmap-spi.c
new file mode 100644
index 0000000000..37ab23a9d0
--- /dev/null
+++ b/drivers/base/regmap/regmap-spi.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Register map access API - SPI support
+//
+// Copyright 2011 Wolfson Microelectronics plc
+//
+// Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/module.h>
+
+#include "internal.h"
+
+struct regmap_async_spi {
+ struct regmap_async core;
+ struct spi_message m;
+ struct spi_transfer t[2];
+};
+
+static void regmap_spi_complete(void *data)
+{
+ struct regmap_async_spi *async = data;
+
+ regmap_async_complete_cb(&async->core, async->m.status);
+}
+
+static int regmap_spi_write(void *context, const void *data, size_t count)
+{
+ struct device *dev = context;
+ struct spi_device *spi = to_spi_device(dev);
+
+ return spi_write(spi, data, count);
+}
+
+static int regmap_spi_gather_write(void *context,
+ const void *reg, size_t reg_len,
+ const void *val, size_t val_len)
+{
+ struct device *dev = context;
+ struct spi_device *spi = to_spi_device(dev);
+ struct spi_message m;
+ struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, },
+ { .tx_buf = val, .len = val_len, }, };
+
+ spi_message_init(&m);
+ spi_message_add_tail(&t[0], &m);
+ spi_message_add_tail(&t[1], &m);
+
+ return spi_sync(spi, &m);
+}
+
+static int regmap_spi_async_write(void *context,
+ const void *reg, size_t reg_len,
+ const void *val, size_t val_len,
+ struct regmap_async *a)
+{
+ struct regmap_async_spi *async = container_of(a,
+ struct regmap_async_spi,
+ core);
+ struct device *dev = context;
+ struct spi_device *spi = to_spi_device(dev);
+
+ async->t[0].tx_buf = reg;
+ async->t[0].len = reg_len;
+ async->t[1].tx_buf = val;
+ async->t[1].len = val_len;
+
+ spi_message_init(&async->m);
+ spi_message_add_tail(&async->t[0], &async->m);
+ if (val)
+ spi_message_add_tail(&async->t[1], &async->m);
+
+ async->m.complete = regmap_spi_complete;
+ async->m.context = async;
+
+ return spi_async(spi, &async->m);
+}
+
+static struct regmap_async *regmap_spi_async_alloc(void)
+{
+ struct regmap_async_spi *async_spi;
+
+ async_spi = kzalloc(sizeof(*async_spi), GFP_KERNEL);
+ if (!async_spi)
+ return NULL;
+
+ return &async_spi->core;
+}
+
+static int regmap_spi_read(void *context,
+ const void *reg, size_t reg_size,
+ void *val, size_t val_size)
+{
+ struct device *dev = context;
+ struct spi_device *spi = to_spi_device(dev);
+
+ return spi_write_then_read(spi, reg, reg_size, val, val_size);
+}
+
+static const struct regmap_bus regmap_spi = {
+ .write = regmap_spi_write,
+ .gather_write = regmap_spi_gather_write,
+ .async_write = regmap_spi_async_write,
+ .async_alloc = regmap_spi_async_alloc,
+ .read = regmap_spi_read,
+ .read_flag_mask = 0x80,
+ .reg_format_endian_default = REGMAP_ENDIAN_BIG,
+ .val_format_endian_default = REGMAP_ENDIAN_BIG,
+};
+
+static const struct regmap_bus *regmap_get_spi_bus(struct spi_device *spi,
+ const struct regmap_config *config)
+{
+ size_t max_size = spi_max_transfer_size(spi);
+ size_t max_msg_size, reg_reserve_size;
+ struct regmap_bus *bus;
+
+ if (max_size != SIZE_MAX) {
+ bus = kmemdup(&regmap_spi, sizeof(*bus), GFP_KERNEL);
+ if (!bus)
+ return ERR_PTR(-ENOMEM);
+
+ max_msg_size = spi_max_message_size(spi);
+ reg_reserve_size = config->reg_bits / BITS_PER_BYTE
+ + config->pad_bits / BITS_PER_BYTE;
+ if (max_size + reg_reserve_size > max_msg_size)
+ max_size -= reg_reserve_size;
+
+ bus->free_on_exit = true;
+ bus->max_raw_read = max_size;
+ bus->max_raw_write = max_size;
+
+ return bus;
+ }
+
+ return &regmap_spi;
+}
+
+struct regmap *__regmap_init_spi(struct spi_device *spi,
+ const struct regmap_config *config,
+ struct lock_class_key *lock_key,
+ const char *lock_name)
+{
+ const struct regmap_bus *bus = regmap_get_spi_bus(spi, config);
+
+ if (IS_ERR(bus))
+ return ERR_CAST(bus);
+
+ return __regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name);
+}
+EXPORT_SYMBOL_GPL(__regmap_init_spi);
+
+struct regmap *__devm_regmap_init_spi(struct spi_device *spi,
+ const struct regmap_config *config,
+ struct lock_class_key *lock_key,
+ const char *lock_name)
+{
+ const struct regmap_bus *bus = regmap_get_spi_bus(spi, config);
+
+ if (IS_ERR(bus))
+ return ERR_CAST(bus);
+
+ return __devm_regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name);
+}
+EXPORT_SYMBOL_GPL(__devm_regmap_init_spi);
+
+MODULE_LICENSE("GPL");