misc: add sl28cpld base driver

Add a multi-function device driver which will probe its children and
provides methods to access the device.

Signed-off-by: Michael Walle <michael@walle.cc>
[Rebased]
Signed-off-by: Priyanka Jain <priyanka.jain@nxp.com>

MAINTAINERS

@@ -1161,6 +1161,11 @@ S:	Maintained
 T:	git https://source.denx.de/u-boot/custodians/u-boot-sh.git
 F:	arch/sh/
 
+SL28CLPD
+M:	Michael Walle <michael@walle.cc>
+S:	Maintained
+F:	drivers/misc/sl28cpld.c
+
 SPI
 M:	Jagan Teki <jagan@amarulasolutions.com>
 S:	Maintained

drivers/misc/Kconfig

@@ -512,4 +512,12 @@ config ESM_PMIC
 config FSL_IFC
 	bool
 
+config SL28CPLD
+	bool "Enable Kontron sl28cpld multi-function driver"
+	depends on DM_I2C
+	help
+	  Support for the Kontron sl28cpld management controller. This is
+	  the base driver which provides common access methods for the
+	  sub-drivers.
+
 endmenu

drivers/misc/Makefile

@@ -82,3 +82,4 @@ obj-$(CONFIG_MICROCHIP_FLEXCOM) += microchip_flexcom.o
 obj-$(CONFIG_K3_AVS0) += k3_avs.o
 obj-$(CONFIG_ESM_K3) += k3_esm.o
 obj-$(CONFIG_ESM_PMIC) += esm_pmic.o
+obj-$(CONFIG_SL28CPLD) += sl28cpld.o

drivers/misc/sl28cpld.c

@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2021 Michael Walle <michael@walle.cc>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <i2c.h>
+
+struct sl28cpld_child_plat {
+	uint offset;
+};
+
+/*
+ * The access methods works either with the first argument being a child
+ * device or with the MFD device itself.
+ */
+static int sl28cpld_read_child(struct udevice *dev, uint offset)
+{
+	struct sl28cpld_child_plat *plat = dev_get_parent_plat(dev);
+	struct udevice *mfd = dev_get_parent(dev);
+
+	return dm_i2c_reg_read(mfd, offset + plat->offset);
+}
+
+int sl28cpld_read(struct udevice *dev, uint offset)
+{
+	if (dev->driver == DM_DRIVER_GET(sl28cpld))
+		return dm_i2c_reg_read(dev, offset);
+	else
+		return sl28cpld_read_child(dev, offset);
+}
+
+static int sl28cpld_write_child(struct udevice *dev, uint offset,
+				uint8_t value)
+{
+	struct sl28cpld_child_plat *plat = dev_get_parent_plat(dev);
+	struct udevice *mfd = dev_get_parent(dev);
+
+	return dm_i2c_reg_write(mfd, offset + plat->offset, value);
+}
+
+int sl28cpld_write(struct udevice *dev, uint offset, uint8_t value)
+{
+	if (dev->driver == DM_DRIVER_GET(sl28cpld))
+		return dm_i2c_reg_write(dev, offset, value);
+	else
+		return sl28cpld_write_child(dev, offset, value);
+}
+
+int sl28cpld_update(struct udevice *dev, uint offset, uint8_t clear,
+		    uint8_t set)
+{
+	int val;
+
+	val = sl28cpld_read(dev, offset);
+	if (val < 0)
+		return val;
+
+	val &= ~clear;
+	val |= set;
+
+	return sl28cpld_write(dev, offset, val);
+}
+
+static int sl28cpld_probe(struct udevice *dev)
+{
+	i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
+			   DM_I2C_CHIP_WR_ADDRESS);
+
+	return 0;
+}
+
+static int sl28cpld_child_post_bind(struct udevice *dev)
+{
+	struct sl28cpld_child_plat *plat = dev_get_parent_plat(dev);
+	int offset;
+
+	if (!dev_has_ofnode(dev))
+		return 0;
+
+	offset = dev_read_u32_default(dev, "reg", -1);
+	if (offset == -1)
+		return -EINVAL;
+
+	plat->offset = offset;
+
+	return 0;
+}
+
+static const struct udevice_id sl28cpld_ids[] = {
+	{ .compatible = "kontron,sl28cpld" },
+	{}
+};
+
+U_BOOT_DRIVER(sl28cpld) = {
+	.name		= "sl28cpld",
+	.id		= UCLASS_NOP,
+	.of_match	= sl28cpld_ids,
+	.probe		= sl28cpld_probe,
+	.bind		= dm_scan_fdt_dev,
+	.flags		= DM_FLAG_PRE_RELOC,
+	.per_child_plat_auto = sizeof(struct sl28cpld_child_plat),
+	.child_post_bind = sl28cpld_child_post_bind,
+};

include/sl28cpld.h

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2021 Michael Walle <michael@walle.cc>
+ */
+
+#ifndef __SL28CPLD_H
+#define __SL28CPLD_H
+
+int sl28cpld_read(struct udevice *dev, uint offset);
+int sl28cpld_write(struct udevice *dev, uint offset, uint8_t value);
+int sl28cpld_update(struct udevice *dev, uint offset, uint8_t clear,
+		    uint8_t set);
+
+#endif