mfd: Add MFD driver for ATC260x PMICs

Add initial support for the Actions Semi ATC260x PMICs which integrates
Audio Codec, Power management, Clock generation and GPIO controller
blocks.

For the moment this driver only supports Regulator, Poweroff and Onkey
functionalities for the ATC2603C and ATC2609A chip variants.

Since the PMICs can be accessed using both I2C and SPI buses, the
following driver structure has been adopted:

           -----> atc260x-core.c (Implements core functionalities)
          /
ATC260x --------> atc260x-i2c.c (Implements I2C interface)
          \
           -----> atc260x-spi.c (Implements SPI interface - TODO)

Co-developed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 64 insertions, 0 deletions

diff --git a/drivers/mfd/atc260x-i2c.c b/drivers/mfd/atc260x-i2c.c
new file mode 100644
index 000000000000..362005703367
--- /dev/null
+++ b/drivers/mfd/atc260x-i2c.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * I2C bus interface for ATC260x PMICs
+ *
+ * Copyright (C) 2019 Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+ * Copyright (C) 2020 Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
+ */
+
+#include <linux/i2c.h>
+#include <linux/mfd/atc260x/core.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+static int atc260x_i2c_probe(struct i2c_client *client,
+			     const struct i2c_device_id *id)
+{
+	struct atc260x *atc260x;
+	struct regmap_config regmap_cfg;
+	int ret;
+
+	atc260x = devm_kzalloc(&client->dev, sizeof(*atc260x), GFP_KERNEL);
+	if (!atc260x)
+		return -ENOMEM;
+
+	atc260x->dev = &client->dev;
+	atc260x->irq = client->irq;
+
+	ret = atc260x_match_device(atc260x, &regmap_cfg);
+	if (ret)
+		return ret;
+
+	i2c_set_clientdata(client, atc260x);
+
+	atc260x->regmap = devm_regmap_init_i2c(client, &regmap_cfg);
+	if (IS_ERR(atc260x->regmap)) {
+		ret = PTR_ERR(atc260x->regmap);
+		dev_err(&client->dev, "failed to init regmap: %d\n", ret);
+		return ret;
+	}
+
+	return atc260x_device_probe(atc260x);
+}
+
+const struct of_device_id atc260x_i2c_of_match[] = {
+	{ .compatible = "actions,atc2603c", .data = (void *)ATC2603C },
+	{ .compatible = "actions,atc2609a", .data = (void *)ATC2609A },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, atc260x_i2c_of_match);
+
+static struct i2c_driver atc260x_i2c_driver = {
+	.driver = {
+		.name = "atc260x",
+		.of_match_table	= of_match_ptr(atc260x_i2c_of_match),
+	},
+	.probe = atc260x_i2c_probe,
+};
+module_i2c_driver(atc260x_i2c_driver);
+
+MODULE_DESCRIPTION("ATC260x PMICs I2C bus interface");
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_AUTHOR("Cristian Ciocaltea <cristian.ciocaltea@gmail.com>");
+MODULE_LICENSE("GPL");