[PATCH 2/4] regmap: Add I2C bus support

Mark Brown
2011-07-18T10:07:53Z

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
---
drivers/base/regmap/Kconfig | 4 +
drivers/base/regmap/Makefile | 1 +
drivers/base/regmap/regmap-i2c.c | 115 ++++++++++++++++++++++++++++++++++++++
include/linux/regmap.h | 2 +
5 files changed, 123 insertions(+), 0 deletions(-)
create mode 100644 drivers/base/regmap/regmap-i2c.c

diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
index fc0eb1d..c374375 100644
--- a/drivers/base/regmap/Kconfig
+++ b/drivers/base/regmap/Kconfig
@@ -4,3 +4,7 @@

config REGMAP
bool
+
+config REGMAP_I2C
+ tristate
+ default I2C
diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile
index 7532e13..ee5109d 100644
--- a/drivers/base/regmap/Makefile
+++ b/drivers/base/regmap/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_REGMAP) += regmap.o
+obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o
diff --git a/drivers/base/regmap/regmap-i2c.c b/drivers/base/regmap/regmap-i2c.c
new file mode 100644
index 0000000..6237003
--- /dev/null
+++ b/drivers/base/regmap/regmap-i2c.c
@@ -0,0 +1,115 @@
+/*
+ * 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 <linux/init.h>
+
+static int regmap_i2c_write(struct device *dev, const void *data, size_t count)
+{
+ 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(struct device *dev,
+ const void *reg, size_t reg_size,
+ const void *val, size_t val_size)
+{
+ 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_PROTOCOL_MANGLING))
+ 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(struct device *dev,
+ const void *reg, size_t reg_size,
+ void *val, size_t val_size)
+{
+ 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 = {
+ .type = &i2c_bus_type,
+ .write = regmap_i2c_write,
+ .gather_write = regmap_i2c_gather_write,
+ .read = regmap_i2c_read,
+ .owner = THIS_MODULE,
+};
+
+/**
+ * regmap_init_i2c(): Initialise register map
+ *
+ * @dev: 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 device *dev,
+ const struct regmap_config *config)
+{
+ return regmap_init(dev, &regmap_i2c, config);
+}
+EXPORT_SYMBOL_GPL(regmap_init_i2c);
+
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index a26c1d0..e509bac 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -59,6 +59,8 @@ struct regmap_bus {
struct regmap *regmap_init(struct device *dev,
const struct regmap_bus *bus,
const struct regmap_config *config);
+struct regmap *regmap_init_i2c(struct device *dev,
+ const struct regmap_config *config);
void regmap_exit(struct regmap *map);
int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
int regmap_raw_write(struct regmap *map, unsigned int reg,
--
1.7.5.4