mfd: sy7636a: Initial commit

Initial support for the Silergy SY7636A Power Management chip.

Signed-off-by: Alistair Francis <alistair@alistair23.me>

drivers/mfd/Kconfig

@@ -1351,6 +1351,15 @@ config MFD_SYSCON
 	  Select this option to enable accessing system control registers
 	  via regmap.
 
+config MFD_SY7636A
+	tristate "Silergy SY7636A Power Management chip"
+	select MFD_CORE
+	select REGMAP_I2C
+	depends on I2C
+	help
+	  Select this option to enable support for the Silergy SY7636A
+	  Power Management chip.
+
 config MFD_DAVINCI_VOICECODEC
 	tristate
 	select MFD_CORE

drivers/mfd/Makefile

@@ -265,6 +265,7 @@ obj-$(CONFIG_MFD_STMFX) 	+= stmfx.o
 obj-$(CONFIG_MFD_KHADAS_MCU) 	+= khadas-mcu.o
 obj-$(CONFIG_MFD_ACER_A500_EC)	+= acer-ec-a500.o
 
+obj-$(CONFIG_MFD_SY7636A)	+= sy7636a.o
 obj-$(CONFIG_SGI_MFD_IOC3)	+= ioc3.o
 obj-$(CONFIG_MFD_SIMPLE_MFD_I2C)	+= simple-mfd-i2c.o
 obj-$(CONFIG_MFD_INTEL_M10_BMC)   += intel-m10-bmc.o

drivers/mfd/sy7636a.c

@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// MFD parent driver for SY7636A chip
+//
+// Copyright (C) 2021 reMarkable AS - http://www.remarkable.com/
+//
+// Authors: Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>
+//          Alistair Francis <alistair@alistair23.me>
+//
+// Based on the lp87565 driver by Keerthy <j-keerthy@ti.com>
+
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+#include <linux/mfd/sy7636a.h>
+
+static const struct regmap_config sy7636a_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static const struct mfd_cell sy7636a_cells[] = {
+	{ .name = "sy7636a-regulator", },
+	{ .name = "sy7636a-temperature", },
+	{ .name = "sy7636a-thermal", },
+};
+
+static const struct of_device_id of_sy7636a_match_table[] = {
+	{ .compatible = "silergy,sy7636a", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_sy7636a_match_table);
+
+static int sy7636a_probe(struct i2c_client *client,
+			 const struct i2c_device_id *ids)
+{
+	struct sy7636a *sy7636a;
+	int ret;
+
+	sy7636a = devm_kzalloc(&client->dev, sizeof(*sy7636a), GFP_KERNEL);
+	if (!sy7636a)
+		return -ENOMEM;
+
+	sy7636a->dev = &client->dev;
+
+	sy7636a->regmap = devm_regmap_init_i2c(client, &sy7636a_regmap_config);
+	if (IS_ERR(sy7636a->regmap)) {
+		ret = PTR_ERR(sy7636a->regmap);
+		dev_err(sy7636a->dev,
+			"Failed to initialize register map: %d\n", ret);
+		return ret;
+	}
+
+	i2c_set_clientdata(client, sy7636a);
+
+	ret = devm_mfd_add_devices(sy7636a->dev, PLATFORM_DEVID_AUTO,
+					sy7636a_cells, ARRAY_SIZE(sy7636a_cells),
+					NULL, 0, NULL);
+	return 0;
+}
+
+static const struct i2c_device_id sy7636a_id_table[] = {
+	{ "sy7636a", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, sy7636a_id_table);
+
+static struct i2c_driver sy7636a_driver = {
+	.driver	= {
+		.name	= "sy7636a",
+		.of_match_table = of_sy7636a_match_table,
+	},
+	.probe = sy7636a_probe,
+	.id_table = sy7636a_id_table,
+};
+module_i2c_driver(sy7636a_driver);
+
+MODULE_AUTHOR("Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>");
+MODULE_DESCRIPTION("Silergy SY7636A Multi-Function Device Driver");
+MODULE_LICENSE("GPL v2");

include/linux/mfd/sy7636a.h

@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Functions to access SY3686A power management chip.
+ *
+ * Copyright (C) 2021 reMarkable AS - http://www.remarkable.com/
+ */
+
+#ifndef __MFD_SY7636A_H
+#define __MFD_SY7636A_H
+
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+
+#define SY7636A_REG_OPERATION_MODE_CRL		0x00
+#define SY7636A_OPERATION_MODE_CRL_VCOMCTL	BIT(6)
+#define SY7636A_OPERATION_MODE_CRL_ONOFF	BIT(7)
+#define SY7636A_REG_VCOM_ADJUST_CTRL_L		0x01
+#define SY7636A_REG_VCOM_ADJUST_CTRL_H		0x02
+#define SY7636A_REG_VCOM_ADJUST_CTRL_MASK	0x01ff
+#define SY7636A_REG_VLDO_VOLTAGE_ADJULST_CTRL	0x03
+#define SY7636A_REG_POWER_ON_DELAY_TIME		0x06
+#define SY7636A_REG_FAULT_FLAG			0x07
+#define SY7636A_FAULT_FLAG_PG			BIT(0)
+#define SY7636A_REG_TERMISTOR_READOUT		0x08
+
+#define SY7636A_REG_MAX				0x08
+
+#define VCOM_MIN		0
+#define VCOM_MAX		5000
+
+#define VCOM_ADJUST_CTRL_MASK	0x1ff
+// Used to shift the high byte
+#define VCOM_ADJUST_CTRL_SHIFT	8
+// Used to scale from VCOM_ADJUST_CTRL to mv
+#define VCOM_ADJUST_CTRL_SCAL	10
+
+#define FAULT_FLAG_SHIFT	1
+
+struct sy7636a {
+	struct device *dev;
+	struct regmap *regmap;
+};
+
+#endif /* __LINUX_MFD_SY7636A_H */