--- /dev/null
+/*
+ * Register map access API - I2C support
+ *
+ * Copyright 2011 Wolfson Microelectronics plc
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#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 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 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 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 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 const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c,
+ const struct regmap_config *config)
+{
+ if (i2c_check_functionality(i2c->adapter, I2C_FUNC_I2C))
+ return ®map_i2c;
+ 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:
+ return ®map_smbus_word;
+ case REGMAP_ENDIAN_BIG:
+ return ®map_smbus_word_swapped;
+ 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))
+ return ®map_smbus_byte;
+
+ return ERR_PTR(-ENOTSUPP);
+}
+
+/**
+ * regmap_init_i2c(): Initialise register map
+ *
+ * @i2c: 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.
+ */
+struct regmap *regmap_init_i2c(struct i2c_client *i2c,
+ const struct regmap_config *config)
+{
+ 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);
+}
+EXPORT_SYMBOL_GPL(regmap_init_i2c);
+
+/**
+ * devm_regmap_init_i2c(): Initialise managed register map
+ *
+ * @i2c: 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.
+ */
+struct regmap *devm_regmap_init_i2c(struct i2c_client *i2c,
+ const struct regmap_config *config)
+{
+ 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);
+}
+EXPORT_SYMBOL_GPL(devm_regmap_init_i2c);
+
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff