i2c: Introduce common module to instantiate CCGx UCSI

Introduce a common module to provide an API to instantiate UCSI device
for Cypress CCGx Type-C controller. Individual bus drivers need to select
this one on demand.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/Kconfig

@@ -9,6 +9,13 @@ menu "I2C Hardware Bus support"
 comment "PC SMBus host controller drivers"
 	depends on PCI
 
+config I2C_CCGX_UCSI
+	tristate
+	help
+	  A common module to provide an API to instantiate UCSI device
+	  for Cypress CCGx Type-C controller. Individual bus drivers
+	  need to select this one on demand.
+
 config I2C_ALI1535
 	tristate "ALI 1535"
 	depends on PCI

drivers/i2c/busses/Makefile

@@ -6,6 +6,9 @@
 # ACPI drivers
 obj-$(CONFIG_I2C_SCMI)		+= i2c-scmi.o
 
+# Auxiliary I2C/SMBus modules
+obj-$(CONFIG_I2C_CCGX_UCSI)	+= i2c-ccgx-ucsi.o
+
 # PC SMBus host controller drivers
 obj-$(CONFIG_I2C_ALI1535)	+= i2c-ali1535.o
 obj-$(CONFIG_I2C_ALI1563)	+= i2c-ali1563.o

drivers/i2c/busses/i2c-ccgx-ucsi.c

+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Instantiate UCSI device for Cypress CCGx Type-C controller.
+ * Derived from i2c-designware-pcidrv.c and i2c-nvidia-gpu.c.
+ */
+
+#include <linux/i2c.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/string.h>
+
+#include "i2c-ccgx-ucsi.h"
+
+struct software_node;
+
+struct i2c_client *i2c_new_ccgx_ucsi(struct i2c_adapter *adapter, int irq,
+				     const struct software_node *swnode)
+{
+	struct i2c_board_info info = {};
+
+	strscpy(info.type, "ccgx-ucsi", sizeof(info.type));
+	info.addr = 0x08;
+	info.irq = irq;
+	info.swnode = swnode;
+
+	return i2c_new_client_device(adapter, &info);
+}
+EXPORT_SYMBOL_GPL(i2c_new_ccgx_ucsi);
+
+MODULE_LICENSE("GPL");

drivers/i2c/busses/i2c-ccgx-ucsi.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __I2C_CCGX_UCSI_H_
+#define __I2C_CCGX_UCSI_H_
+
+struct i2c_adapter;
+struct i2c_client;
+struct software_node;
+
+struct i2c_client *i2c_new_ccgx_ucsi(struct i2c_adapter *adapter, int irq,
+				     const struct software_node *swnode);
+#endif /* __I2C_CCGX_UCSI_H_ */