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path: root/drivers/base/regmap/regmap-i2c.c
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Diffstat (limited to 'drivers/base/regmap/regmap-i2c.c')
-rw-r--r--drivers/base/regmap/regmap-i2c.c399
1 files changed, 399 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap-i2c.c b/drivers/base/regmap/regmap-i2c.c
new file mode 100644
index 0000000000..3ec611dc0c
--- /dev/null
+++ b/drivers/base/regmap/regmap-i2c.c
@@ -0,0 +1,399 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Register map access API - I2C support
+//
+// Copyright 2011 Wolfson Microelectronics plc
+//
+// Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+
+#include <linux/regmap.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+
+#include "internal.h"
+
+static int regmap_smbus_byte_reg_read(void *context, unsigned int reg,
+ unsigned int *val)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+ int ret;
+
+ if (reg > 0xff)
+ return -EINVAL;
+
+ ret = i2c_smbus_read_byte_data(i2c, reg);
+ if (ret < 0)
+ return ret;
+
+ *val = ret;
+
+ return 0;
+}
+
+static int regmap_smbus_byte_reg_write(void *context, unsigned int reg,
+ unsigned int val)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+
+ if (val > 0xff || reg > 0xff)
+ return -EINVAL;
+
+ return i2c_smbus_write_byte_data(i2c, reg, val);
+}
+
+static const struct regmap_bus regmap_smbus_byte = {
+ .reg_write = regmap_smbus_byte_reg_write,
+ .reg_read = regmap_smbus_byte_reg_read,
+};
+
+static int regmap_smbus_word_reg_read(void *context, unsigned int reg,
+ unsigned int *val)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+ int ret;
+
+ if (reg > 0xff)
+ return -EINVAL;
+
+ ret = i2c_smbus_read_word_data(i2c, reg);
+ if (ret < 0)
+ return ret;
+
+ *val = ret;
+
+ return 0;
+}
+
+static int regmap_smbus_word_reg_write(void *context, unsigned int reg,
+ unsigned int val)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+
+ if (val > 0xffff || reg > 0xff)
+ return -EINVAL;
+
+ return i2c_smbus_write_word_data(i2c, reg, val);
+}
+
+static const struct regmap_bus regmap_smbus_word = {
+ .reg_write = regmap_smbus_word_reg_write,
+ .reg_read = regmap_smbus_word_reg_read,
+};
+
+static int regmap_smbus_word_read_swapped(void *context, unsigned int reg,
+ unsigned int *val)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+ int ret;
+
+ if (reg > 0xff)
+ return -EINVAL;
+
+ ret = i2c_smbus_read_word_swapped(i2c, reg);
+ if (ret < 0)
+ return ret;
+
+ *val = ret;
+
+ return 0;
+}
+
+static int regmap_smbus_word_write_swapped(void *context, unsigned int reg,
+ unsigned int val)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+
+ if (val > 0xffff || reg > 0xff)
+ return -EINVAL;
+
+ return i2c_smbus_write_word_swapped(i2c, reg, val);
+}
+
+static const struct regmap_bus regmap_smbus_word_swapped = {
+ .reg_write = regmap_smbus_word_write_swapped,
+ .reg_read = regmap_smbus_word_read_swapped,
+};
+
+static int regmap_i2c_write(void *context, const void *data, size_t count)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+ int ret;
+
+ ret = i2c_master_send(i2c, data, count);
+ if (ret == count)
+ return 0;
+ else if (ret < 0)
+ return ret;
+ else
+ return -EIO;
+}
+
+static int regmap_i2c_gather_write(void *context,
+ const void *reg, size_t reg_size,
+ const void *val, size_t val_size)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+ struct i2c_msg xfer[2];
+ int ret;
+
+ /* If the I2C controller can't do a gather tell the core, it
+ * will substitute in a linear write for us.
+ */
+ if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_NOSTART))
+ return -ENOTSUPP;
+
+ xfer[0].addr = i2c->addr;
+ xfer[0].flags = 0;
+ xfer[0].len = reg_size;
+ xfer[0].buf = (void *)reg;
+
+ xfer[1].addr = i2c->addr;
+ xfer[1].flags = I2C_M_NOSTART;
+ xfer[1].len = val_size;
+ xfer[1].buf = (void *)val;
+
+ ret = i2c_transfer(i2c->adapter, xfer, 2);
+ if (ret == 2)
+ return 0;
+ if (ret < 0)
+ return ret;
+ else
+ return -EIO;
+}
+
+static int regmap_i2c_read(void *context,
+ const void *reg, size_t reg_size,
+ void *val, size_t val_size)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+ struct i2c_msg xfer[2];
+ int ret;
+
+ xfer[0].addr = i2c->addr;
+ xfer[0].flags = 0;
+ xfer[0].len = reg_size;
+ xfer[0].buf = (void *)reg;
+
+ xfer[1].addr = i2c->addr;
+ xfer[1].flags = I2C_M_RD;
+ xfer[1].len = val_size;
+ xfer[1].buf = val;
+
+ ret = i2c_transfer(i2c->adapter, xfer, 2);
+ if (ret == 2)
+ return 0;
+ else if (ret < 0)
+ return ret;
+ else
+ return -EIO;
+}
+
+static const struct regmap_bus regmap_i2c = {
+ .write = regmap_i2c_write,
+ .gather_write = regmap_i2c_gather_write,
+ .read = regmap_i2c_read,
+ .reg_format_endian_default = REGMAP_ENDIAN_BIG,
+ .val_format_endian_default = REGMAP_ENDIAN_BIG,
+};
+
+static int regmap_i2c_smbus_i2c_write(void *context, const void *data,
+ size_t count)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+
+ if (count < 1)
+ return -EINVAL;
+
+ --count;
+ return i2c_smbus_write_i2c_block_data(i2c, ((u8 *)data)[0], count,
+ ((u8 *)data + 1));
+}
+
+static int regmap_i2c_smbus_i2c_read(void *context, const void *reg,
+ size_t reg_size, void *val,
+ size_t val_size)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+ int ret;
+
+ if (reg_size != 1 || val_size < 1)
+ return -EINVAL;
+
+ ret = i2c_smbus_read_i2c_block_data(i2c, ((u8 *)reg)[0], val_size, val);
+ if (ret == val_size)
+ return 0;
+ else if (ret < 0)
+ return ret;
+ else
+ return -EIO;
+}
+
+static const struct regmap_bus regmap_i2c_smbus_i2c_block = {
+ .write = regmap_i2c_smbus_i2c_write,
+ .read = regmap_i2c_smbus_i2c_read,
+ .max_raw_read = I2C_SMBUS_BLOCK_MAX - 1,
+ .max_raw_write = I2C_SMBUS_BLOCK_MAX - 1,
+};
+
+static int regmap_i2c_smbus_i2c_write_reg16(void *context, const void *data,
+ size_t count)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+
+ if (count < 2)
+ return -EINVAL;
+
+ count--;
+ return i2c_smbus_write_i2c_block_data(i2c, ((u8 *)data)[0], count,
+ (u8 *)data + 1);
+}
+
+static int regmap_i2c_smbus_i2c_read_reg16(void *context, const void *reg,
+ size_t reg_size, void *val,
+ size_t val_size)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+ int ret, count, len = val_size;
+
+ if (reg_size != 2)
+ return -EINVAL;
+
+ ret = i2c_smbus_write_byte_data(i2c, ((u16 *)reg)[0] & 0xff,
+ ((u16 *)reg)[0] >> 8);
+ if (ret < 0)
+ return ret;
+
+ count = 0;
+ do {
+ /* Current Address Read */
+ ret = i2c_smbus_read_byte(i2c);
+ if (ret < 0)
+ break;
+
+ *((u8 *)val++) = ret;
+ count++;
+ len--;
+ } while (len > 0);
+
+ if (count == val_size)
+ return 0;
+ else if (ret < 0)
+ return ret;
+ else
+ return -EIO;
+}
+
+static const struct regmap_bus regmap_i2c_smbus_i2c_block_reg16 = {
+ .write = regmap_i2c_smbus_i2c_write_reg16,
+ .read = regmap_i2c_smbus_i2c_read_reg16,
+ .max_raw_read = I2C_SMBUS_BLOCK_MAX - 2,
+ .max_raw_write = I2C_SMBUS_BLOCK_MAX - 2,
+};
+
+static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c,
+ const struct regmap_config *config)
+{
+ const struct i2c_adapter_quirks *quirks;
+ const struct regmap_bus *bus = NULL;
+ struct regmap_bus *ret_bus;
+ u16 max_read = 0, max_write = 0;
+
+ if (i2c_check_functionality(i2c->adapter, I2C_FUNC_I2C))
+ bus = &regmap_i2c;
+ else if (config->val_bits == 8 && config->reg_bits == 8 &&
+ i2c_check_functionality(i2c->adapter,
+ I2C_FUNC_SMBUS_I2C_BLOCK))
+ bus = &regmap_i2c_smbus_i2c_block;
+ else if (config->val_bits == 8 && config->reg_bits == 16 &&
+ i2c_check_functionality(i2c->adapter,
+ I2C_FUNC_SMBUS_I2C_BLOCK))
+ bus = &regmap_i2c_smbus_i2c_block_reg16;
+ else if (config->val_bits == 16 && config->reg_bits == 8 &&
+ i2c_check_functionality(i2c->adapter,
+ I2C_FUNC_SMBUS_WORD_DATA))
+ switch (regmap_get_val_endian(&i2c->dev, NULL, config)) {
+ case REGMAP_ENDIAN_LITTLE:
+ bus = &regmap_smbus_word;
+ break;
+ case REGMAP_ENDIAN_BIG:
+ bus = &regmap_smbus_word_swapped;
+ break;
+ default: /* everything else is not supported */
+ break;
+ }
+ else if (config->val_bits == 8 && config->reg_bits == 8 &&
+ i2c_check_functionality(i2c->adapter,
+ I2C_FUNC_SMBUS_BYTE_DATA))
+ bus = &regmap_smbus_byte;
+
+ if (!bus)
+ return ERR_PTR(-ENOTSUPP);
+
+ quirks = i2c->adapter->quirks;
+ if (quirks) {
+ if (quirks->max_read_len &&
+ (bus->max_raw_read == 0 || bus->max_raw_read > quirks->max_read_len))
+ max_read = quirks->max_read_len;
+
+ if (quirks->max_write_len &&
+ (bus->max_raw_write == 0 || bus->max_raw_write > quirks->max_write_len))
+ max_write = quirks->max_write_len;
+
+ if (max_read || max_write) {
+ ret_bus = kmemdup(bus, sizeof(*bus), GFP_KERNEL);
+ if (!ret_bus)
+ return ERR_PTR(-ENOMEM);
+ ret_bus->free_on_exit = true;
+ ret_bus->max_raw_read = max_read;
+ ret_bus->max_raw_write = max_write;
+ bus = ret_bus;
+ }
+ }
+
+ return bus;
+}
+
+struct regmap *__regmap_init_i2c(struct i2c_client *i2c,
+ const struct regmap_config *config,
+ struct lock_class_key *lock_key,
+ const char *lock_name)
+{
+ const struct regmap_bus *bus = regmap_get_i2c_bus(i2c, config);
+
+ if (IS_ERR(bus))
+ return ERR_CAST(bus);
+
+ return __regmap_init(&i2c->dev, bus, &i2c->dev, config,
+ lock_key, lock_name);
+}
+EXPORT_SYMBOL_GPL(__regmap_init_i2c);
+
+struct regmap *__devm_regmap_init_i2c(struct i2c_client *i2c,
+ const struct regmap_config *config,
+ struct lock_class_key *lock_key,
+ const char *lock_name)
+{
+ const struct regmap_bus *bus = regmap_get_i2c_bus(i2c, config);
+
+ if (IS_ERR(bus))
+ return ERR_CAST(bus);
+
+ return __devm_regmap_init(&i2c->dev, bus, &i2c->dev, config,
+ lock_key, lock_name);
+}
+EXPORT_SYMBOL_GPL(__devm_regmap_init_i2c);
+
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 18:32:03 +0000