mfd: adp5585: Add Analog Devices ADP5585 core support

The ADP5585 is a 10/11 input/output port expander with a built in keypad
matrix decoder, programmable logic, reset generator, and PWM generator.
This driver supports the chip by modelling it as an MFD device, with two
child devices for the GPIO and PWM functions.

The driver is derived from an initial implementation from NXP, available
in commit 8059835bee19 ("MLK-25917-1 mfd: adp5585: add ADI adp5585 core
support") in their BSP kernel tree. It has been extensively rewritten.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20240722121100.2855-3-laurent.pinchart@ideasonboard.com
Signed-off-by: Lee Jones <lee@kernel.org>

3 files changed, 218 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index bc8be2e593b6..f9325bcce1b9 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -20,6 +20,18 @@ config MFD_CS5535
 	  This is the core driver for CS5535/CS5536 MFD functions.  This is
 	  necessary for using the board's GPIO and MFGPT functionality.
 
+config MFD_ADP5585
+	tristate "Analog Devices ADP5585 keypad decoder and I/O expander driver"
+	select MFD_CORE
+	select REGMAP_I2C
+	depends on I2C
+	depends on OF || COMPILE_TEST
+	help
+	  Say yes here to add support for the Analog Devices ADP5585 GPIO
+	  expander, PWM and keypad controller. This includes the I2C driver and
+	  the core APIs _only_, you have to select individual components like
+	  the GPIO and PWM functions under the corresponding menus.
+
 config MFD_ALTERA_A10SR
 	bool "Altera Arria10 DevKit System Resource chip"
 	depends on ARCH_INTEL_SOCFPGA && SPI_MASTER=y && OF
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 02b651cd7535..2a9f91e81af8 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -193,6 +193,7 @@ obj-$(CONFIG_MFD_DB8500_PRCMU)	+= db8500-prcmu.o
 obj-$(CONFIG_AB8500_CORE)	+= ab8500-core.o ab8500-sysctrl.o
 obj-$(CONFIG_MFD_TIMBERDALE)    += timberdale.o
 obj-$(CONFIG_PMIC_ADP5520)	+= adp5520.o
+obj-$(CONFIG_MFD_ADP5585)	+= adp5585.o
 obj-$(CONFIG_MFD_KEMPLD)	+= kempld-core.o
 obj-$(CONFIG_MFD_INTEL_QUARK_I2C_GPIO)	+= intel_quark_i2c_gpio.o
 obj-$(CONFIG_LPC_SCH)		+= lpc_sch.o
diff --git a/drivers/mfd/adp5585.c b/drivers/mfd/adp5585.c
new file mode 100644
index 000000000000..160e0b38106a
--- /dev/null
+++ b/drivers/mfd/adp5585.c
@@ -0,0 +1,205 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Analog Devices ADP5585 I/O expander, PWM controller and keypad controller
+ *
+ * Copyright 2022 NXP
+ * Copyright 2024 Ideas on Board Oy
+ */
+
+#include <linux/array_size.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/mfd/adp5585.h>
+#include <linux/mfd/core.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+static const struct mfd_cell adp5585_devs[] = {
+	{ .name = "adp5585-gpio", },
+	{ .name = "adp5585-pwm", },
+};
+
+static const struct regmap_range adp5585_volatile_ranges[] = {
+	regmap_reg_range(ADP5585_ID, ADP5585_GPI_STATUS_B),
+};
+
+static const struct regmap_access_table adp5585_volatile_regs = {
+	.yes_ranges = adp5585_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(adp5585_volatile_ranges),
+};
+
+/*
+ * Chip variants differ in the default configuration of pull-up and pull-down
+ * resistors, and therefore have different default register values:
+ *
+ * - The -00, -01 and -03 variants (collectively referred to as
+ *   ADP5585_REGMAP_00) have pull-up on all GPIO pins by default.
+ * - The -02 variant has no default pull-up or pull-down resistors.
+ * - The -04 variant has default pull-down resistors on all GPIO pins.
+ */
+
+static const u8 adp5585_regmap_defaults_00[ADP5585_MAX_REG + 1] = {
+	/* 0x00 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x08 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x10 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x18 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x20 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x28 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x30 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x38 */ 0x00, 0x00, 0x00, 0x00, 0x00,
+};
+
+static const u8 adp5585_regmap_defaults_02[ADP5585_MAX_REG + 1] = {
+	/* 0x00 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x08 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x10 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xc3,
+	/* 0x18 */ 0x03, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x20 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x28 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x30 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x38 */ 0x00, 0x00, 0x00, 0x00, 0x00,
+};
+
+static const u8 adp5585_regmap_defaults_04[ADP5585_MAX_REG + 1] = {
+	/* 0x00 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x08 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x10 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x55,
+	/* 0x18 */ 0x05, 0x55, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x20 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x28 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x30 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	/* 0x38 */ 0x00, 0x00, 0x00, 0x00, 0x00,
+};
+
+enum adp5585_regmap_type {
+	ADP5585_REGMAP_00,
+	ADP5585_REGMAP_02,
+	ADP5585_REGMAP_04,
+};
+
+static const struct regmap_config adp5585_regmap_configs[] = {
+	[ADP5585_REGMAP_00] = {
+		.reg_bits = 8,
+		.val_bits = 8,
+		.max_register = ADP5585_MAX_REG,
+		.volatile_table = &adp5585_volatile_regs,
+		.cache_type = REGCACHE_MAPLE,
+		.reg_defaults_raw = adp5585_regmap_defaults_00,
+		.num_reg_defaults_raw = sizeof(adp5585_regmap_defaults_00),
+	},
+	[ADP5585_REGMAP_02] = {
+		.reg_bits = 8,
+		.val_bits = 8,
+		.max_register = ADP5585_MAX_REG,
+		.volatile_table = &adp5585_volatile_regs,
+		.cache_type = REGCACHE_MAPLE,
+		.reg_defaults_raw = adp5585_regmap_defaults_02,
+		.num_reg_defaults_raw = sizeof(adp5585_regmap_defaults_02),
+	},
+	[ADP5585_REGMAP_04] = {
+		.reg_bits = 8,
+		.val_bits = 8,
+		.max_register = ADP5585_MAX_REG,
+		.volatile_table = &adp5585_volatile_regs,
+		.cache_type = REGCACHE_MAPLE,
+		.reg_defaults_raw = adp5585_regmap_defaults_04,
+		.num_reg_defaults_raw = sizeof(adp5585_regmap_defaults_04),
+	},
+};
+
+static int adp5585_i2c_probe(struct i2c_client *i2c)
+{
+	const struct regmap_config *regmap_config;
+	struct adp5585_dev *adp5585;
+	unsigned int id;
+	int ret;
+
+	adp5585 = devm_kzalloc(&i2c->dev, sizeof(*adp5585), GFP_KERNEL);
+	if (!adp5585)
+		return -ENOMEM;
+
+	i2c_set_clientdata(i2c, adp5585);
+
+	regmap_config = i2c_get_match_data(i2c);
+	adp5585->regmap = devm_regmap_init_i2c(i2c, regmap_config);
+	if (IS_ERR(adp5585->regmap))
+		return dev_err_probe(&i2c->dev, PTR_ERR(adp5585->regmap),
+				     "Failed to initialize register map\n");
+
+	ret = regmap_read(adp5585->regmap, ADP5585_ID, &id);
+	if (ret)
+		return dev_err_probe(&i2c->dev, ret,
+				     "Failed to read device ID\n");
+
+	if ((id & ADP5585_MAN_ID_MASK) != ADP5585_MAN_ID_VALUE)
+		return dev_err_probe(&i2c->dev, -ENODEV,
+				     "Invalid device ID 0x%02x\n", id);
+
+	ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_AUTO,
+				   adp5585_devs, ARRAY_SIZE(adp5585_devs),
+				   NULL, 0, NULL);
+	if (ret)
+		return dev_err_probe(&i2c->dev, ret,
+				     "Failed to add child devices\n");
+
+	return 0;
+}
+
+static int adp5585_suspend(struct device *dev)
+{
+	struct adp5585_dev *adp5585 = dev_get_drvdata(dev);
+
+	regcache_cache_only(adp5585->regmap, true);
+
+	return 0;
+}
+
+static int adp5585_resume(struct device *dev)
+{
+	struct adp5585_dev *adp5585 = dev_get_drvdata(dev);
+
+	regcache_cache_only(adp5585->regmap, false);
+	regcache_mark_dirty(adp5585->regmap);
+
+	return regcache_sync(adp5585->regmap);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(adp5585_pm, adp5585_suspend, adp5585_resume);
+
+static const struct of_device_id adp5585_of_match[] = {
+	{
+		.compatible = "adi,adp5585-00",
+		.data = &adp5585_regmap_configs[ADP5585_REGMAP_00],
+	}, {
+		.compatible = "adi,adp5585-01",
+		.data = &adp5585_regmap_configs[ADP5585_REGMAP_00],
+	}, {
+		.compatible = "adi,adp5585-02",
+		.data = &adp5585_regmap_configs[ADP5585_REGMAP_02],
+	}, {
+		.compatible = "adi,adp5585-03",
+		.data = &adp5585_regmap_configs[ADP5585_REGMAP_00],
+	}, {
+		.compatible = "adi,adp5585-04",
+		.data = &adp5585_regmap_configs[ADP5585_REGMAP_04],
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, adp5585_of_match);
+
+static struct i2c_driver adp5585_i2c_driver = {
+	.driver = {
+		.name = "adp5585",
+		.of_match_table = adp5585_of_match,
+		.pm = pm_sleep_ptr(&adp5585_pm),
+	},
+	.probe = adp5585_i2c_probe,
+};
+module_i2c_driver(adp5585_i2c_driver);
+
+MODULE_DESCRIPTION("ADP5585 core driver");
+MODULE_AUTHOR("Haibo Chen <haibo.chen@nxp.com>");
+MODULE_LICENSE("GPL");