mfd: cs42l43: Add support for cs42l43 core driver

The CS42L43 is an audio CODEC with integrated MIPI SoundWire interface
(Version 1.2.1 compliant), I2C, SPI, and I2S/TDM interfaces designed
for portable applications. It provides a high dynamic range, stereo
DAC for headphone output, two integrated Class D amplifiers for
loudspeakers, and two ADCs for wired headset microphone input or
stereo line input. PDM inputs are provided for digital microphones.

The MFD component registers and initialises the device and provides
PM/system power management.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230804104602.395892-4-ckeepax@opensource.cirrus.com
Signed-off-by: Lee Jones <lee@kernel.org>

1 files changed, 98 insertions, 0 deletions

diff --git a/drivers/mfd/cs42l43-i2c.c b/drivers/mfd/cs42l43-i2c.c
new file mode 100644
index 000000000000..4922211680c9
--- /dev/null
+++ b/drivers/mfd/cs42l43-i2c.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CS42L43 I2C driver
+ *
+ * Copyright (C) 2022-2023 Cirrus Logic, Inc. and
+ *                         Cirrus Logic International Semiconductor Ltd.
+ */
+
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/mfd/cs42l43-regs.h>
+#include <linux/module.h>
+
+#include "cs42l43.h"
+
+static const struct regmap_config cs42l43_i2c_regmap = {
+	.reg_bits		= 32,
+	.reg_stride		= 4,
+	.val_bits		= 32,
+	.reg_format_endian	= REGMAP_ENDIAN_BIG,
+	.val_format_endian	= REGMAP_ENDIAN_BIG,
+
+	.max_register		= CS42L43_MCU_RAM_MAX,
+	.readable_reg		= cs42l43_readable_register,
+	.volatile_reg		= cs42l43_volatile_register,
+	.precious_reg		= cs42l43_precious_register,
+
+	.cache_type		= REGCACHE_MAPLE,
+	.reg_defaults		= cs42l43_reg_default,
+	.num_reg_defaults	= ARRAY_SIZE(cs42l43_reg_default),
+};
+
+static int cs42l43_i2c_probe(struct i2c_client *i2c)
+{
+	struct cs42l43 *cs42l43;
+	int ret;
+
+	cs42l43 = devm_kzalloc(&i2c->dev, sizeof(*cs42l43), GFP_KERNEL);
+	if (!cs42l43)
+		return -ENOMEM;
+
+	cs42l43->dev = &i2c->dev;
+	cs42l43->irq = i2c->irq;
+	/* A device on an I2C is always attached by definition. */
+	cs42l43->attached = true;
+
+	cs42l43->regmap = devm_regmap_init_i2c(i2c, &cs42l43_i2c_regmap);
+	if (IS_ERR(cs42l43->regmap)) {
+		ret = PTR_ERR(cs42l43->regmap);
+		dev_err(cs42l43->dev, "Failed to allocate regmap: %d\n", ret);
+		return ret;
+	}
+
+	return cs42l43_dev_probe(cs42l43);
+}
+
+static void cs42l43_i2c_remove(struct i2c_client *i2c)
+{
+	struct cs42l43 *cs42l43 = dev_get_drvdata(&i2c->dev);
+
+	cs42l43_dev_remove(cs42l43);
+}
+
+#if IS_ENABLED(CONFIG_OF)
+static const struct of_device_id cs42l43_of_match[] = {
+	{ .compatible = "cirrus,cs42l43", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, cs42l43_of_match);
+#endif
+
+#if IS_ENABLED(CONFIG_ACPI)
+static const struct acpi_device_id cs42l43_acpi_match[] = {
+	{ "CSC4243", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, cs42l43_acpi_match);
+#endif
+
+static struct i2c_driver cs42l43_i2c_driver = {
+	.driver = {
+		.name			= "cs42l43",
+		.pm			= pm_ptr(&cs42l43_pm_ops),
+		.of_match_table		= of_match_ptr(cs42l43_of_match),
+		.acpi_match_table	= ACPI_PTR(cs42l43_acpi_match),
+	},
+
+	.probe		= cs42l43_i2c_probe,
+	.remove		= cs42l43_i2c_remove,
+};
+module_i2c_driver(cs42l43_i2c_driver);
+
+MODULE_IMPORT_NS(MFD_CS42L43);
+
+MODULE_DESCRIPTION("CS42L43 I2C Driver");
+MODULE_AUTHOR("Charles Keepax <ckeepax@opensource.cirrus.com>");
+MODULE_LICENSE("GPL");