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-rw-r--r--drivers/mfd/simple-mfd-i2c.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c
new file mode 100644
index 000000000..87f684cff
--- /dev/null
+++ b/drivers/mfd/simple-mfd-i2c.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Simple MFD - I2C
+ *
+ * This driver creates a single register map with the intention for it to be
+ * shared by all sub-devices. Children can use their parent's device structure
+ * (dev.parent) in order to reference it.
+ *
+ * Once the register map has been successfully initialised, any sub-devices
+ * represented by child nodes in Device Tree will be subsequently registered.
+ */
+
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+
+static const struct regmap_config simple_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static int simple_mfd_i2c_probe(struct i2c_client *i2c)
+{
+ const struct regmap_config *config;
+ struct regmap *regmap;
+
+ config = device_get_match_data(&i2c->dev);
+ if (!config)
+ config = &simple_regmap_config;
+
+ regmap = devm_regmap_init_i2c(i2c, config);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ return devm_of_platform_populate(&i2c->dev);
+}
+
+static const struct of_device_id simple_mfd_i2c_of_match[] = {
+ { .compatible = "kontron,sl28cpld" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match);
+
+static struct i2c_driver simple_mfd_i2c_driver = {
+ .probe_new = simple_mfd_i2c_probe,
+ .driver = {
+ .name = "simple-mfd-i2c",
+ .of_match_table = simple_mfd_i2c_of_match,
+ },
+};
+module_i2c_driver(simple_mfd_i2c_driver);
+
+MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
+MODULE_DESCRIPTION("Simple MFD - I2C driver");
+MODULE_LICENSE("GPL v2");