[PATCH v2 1/3] mfd: add support for Cypress CYUSBS234 USB Serial Bridge controller

[Muthu Mani <muth@xxxxxxxxxxx>]

Adds support for USB-I2C/GPIO interfaces of Cypress Semiconductor
CYUSBS234 USB-Serial Bridge controller.

Details about the device can be found at:
http://www.cypress.com/?rID=84126

Signed-off-by: Muthu Mani <muth@xxxxxxxxxxx>
Signed-off-by: Rajaram Regupathy <rera@xxxxxxxxxxx>
---
 drivers/mfd/Kconfig           |  12 +++
 drivers/mfd/Makefile          |   1 +
 drivers/mfd/cyusbs23x.c       | 190 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/cyusbs23x.h |  57 +++++++++++++
 4 files changed, 260 insertions(+)
 create mode 100644 drivers/mfd/cyusbs23x.c
 create mode 100644 include/linux/mfd/cyusbs23x.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index de5abf2..a31e9e3 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -116,6 +116,18 @@ config MFD_ASIC3
 	  This driver supports the ASIC3 multifunction chip found on many
 	  PDAs (mainly iPAQ and HTC based ones)
 
+config MFD_CYUSBS23X
+        tristate "Cypress CYUSBS23x USB Serial Bridge controller"
+	select MFD_CORE
+	depends on USB
+	default n
+	help
+	  Say yes here if you want support for Cypress Semiconductor
+	  CYUSBS23x USB-Serial Bridge controller.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called cyusbs23x.
+
 config PMIC_DA903X
 	bool "Dialog Semiconductor DA9030/DA9034 PMIC Support"
 	depends on I2C=y
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index f001487..fc5bcd1 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -151,6 +151,7 @@ si476x-core-y := si476x-cmd.o si476x-prop.o si476x-i2c.o
 obj-$(CONFIG_MFD_SI476X_CORE)	+= si476x-core.o
 
 obj-$(CONFIG_MFD_CS5535)	+= cs5535-mfd.o
+obj-$(CONFIG_MFD_CYUSBS23X)     += cyusbs23x.o
 obj-$(CONFIG_MFD_OMAP_USB_HOST)	+= omap-usb-host.o omap-usb-tll.o
 obj-$(CONFIG_MFD_PM8921_CORE) 	+= pm8921-core.o ssbi.o
 obj-$(CONFIG_TPS65911_COMPARATOR)	+= tps65911-comparator.o
diff --git a/drivers/mfd/cyusbs23x.c b/drivers/mfd/cyusbs23x.c
new file mode 100644
index 0000000..cf2d53b
--- /dev/null
+++ b/drivers/mfd/cyusbs23x.c
@@ -0,0 +1,190 @@
+/*
+ * Cypress USB-Serial Bridge Controller USB adapter driver
+ *
+ * Copyright (c) 2014 Cypress Semiconductor Corporation.
+ *
+ * Author:
+ *   Muthu Mani <muth@xxxxxxxxxxx>
+ *
+ * Additional contributors include:
+ *   Rajaram Regupathy <rera@xxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+/*
+ * This is core MFD driver for Cypress Semiconductor CYUSBS234 USB-Serial
+ * Bridge controller. CYUSBS234 offers a single channel serial interface
+ * (I2C/SPI/UART). It can be configured to enable either of I2C, SPI, UART
+ * interfaces. The GPIOs are also available to access.
+ * Details about the device can be found at:
+ *    http://www.cypress.com/?rID=84126
+ *
+ * Separate cell drivers are available for I2C and GPIO. SPI and UART are not
+ * supported yet. All GPIOs are exposed for get operation. However, only
+ * unused GPIOs can be set.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+
+#include <linux/mfd/core.h>
+#include <linux/mfd/cyusbs23x.h>
+
+#include <linux/usb.h>
+
+static const struct usb_device_id cyusbs23x_usb_table[] = {
+	{ USB_DEVICE(0x04b4, 0x0004) },   /* Cypress Semiconductor */
+	{ }                               /* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, cyusbs23x_usb_table);
+
+static const struct mfd_cell cyusbs23x_i2c_devs[] = {
+	{
+		.name = "cyusbs23x-i2c",
+	},
+	{
+		.name = "cyusbs23x-gpio",
+	},
+};
+
+static int update_ep_details(struct usb_interface *interface,
+				struct cyusbs23x *cyusbs)
+{
+	struct usb_host_interface *iface_desc;
+	struct usb_endpoint_descriptor *ep;
+	int i;
+
+	dev_dbg(&interface->dev, "%s\n", __func__);
+
+	iface_desc = interface->cur_altsetting;
+
+	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+
+		dev_dbg(&interface->dev, "%s %d/%d\n",
+			__func__, i, iface_desc->desc.bNumEndpoints);
+
+		ep = &iface_desc->endpoint[i].desc;
+
+		if (!cyusbs->bulk_in_ep_num &&
+			usb_endpoint_is_bulk_in(ep)) {
+			cyusbs->bulk_in_ep_num = ep->bEndpointAddress;
+		}
+		if (!cyusbs->bulk_out_ep_num &&
+			usb_endpoint_is_bulk_out(ep)) {
+			cyusbs->bulk_out_ep_num = ep->bEndpointAddress;
+		}
+		if (!cyusbs->intr_in_ep_num &&
+			usb_endpoint_is_int_in(ep)) {
+			cyusbs->intr_in_ep_num = ep->bEndpointAddress;
+		}
+	}
+
+	dev_dbg(&interface->dev, "%s %d, %d, %d\n",
+		__func__, cyusbs->intr_in_ep_num ,
+		cyusbs->bulk_in_ep_num, cyusbs->bulk_out_ep_num);
+
+	if (!cyusbs->bulk_in_ep_num || !cyusbs->bulk_out_ep_num ||
+		!cyusbs->intr_in_ep_num)
+		return -ENODEV;
+
+	return 0;
+}
+
+static int cyusbs23x_probe(struct usb_interface *interface,
+			   const struct usb_device_id *id)
+{
+	struct cyusbs23x *cyusbs;
+	const struct mfd_cell *cyusbs23x_devs;
+	int ret, mfd_id, ndevs = 0;
+	u8 sub_class;
+
+	cyusbs = kzalloc(sizeof(*cyusbs), GFP_KERNEL);
+	if (cyusbs == NULL)
+		return -ENOMEM;
+
+	mutex_init(&cyusbs->lock);
+
+	cyusbs->usb_dev = usb_get_dev(interface_to_usbdev(interface));
+	cyusbs->usb_intf = interface;
+	cyusbs->intf_num = interface->cur_altsetting->desc.bInterfaceNumber;
+
+	ret = update_ep_details(interface, cyusbs);
+	if (ret < 0) {
+		dev_err(&interface->dev, "invalid interface\n");
+		goto error;
+	}
+
+	usb_set_intfdata(interface, cyusbs);
+
+	dev_dbg(&interface->dev,
+		"binding to %02x:%02x, in bus %03d address %03d\n",
+		le16_to_cpu(cyusbs->usb_dev->descriptor.idVendor),
+		le16_to_cpu(cyusbs->usb_dev->descriptor.idProduct),
+		cyusbs->usb_dev->bus->busnum,
+		cyusbs->usb_dev->devnum);
+
+	sub_class = interface->cur_altsetting->desc.bInterfaceSubClass;
+	switch (sub_class) {
+	case CY_USBS_SCB_I2C:
+		dev_dbg(&interface->dev, "I2C interface found\n");
+		cyusbs23x_devs = cyusbs23x_i2c_devs;
+		ndevs = ARRAY_SIZE(cyusbs23x_i2c_devs);
+		break;
+	default:
+		dev_err(&interface->dev, "unsupported subclass\n");
+		ret = -ENODEV;
+		goto error;
+	}
+
+	mfd_id = cyusbs->usb_dev->bus->busnum << 16 |
+			cyusbs->usb_dev->devnum << 8 | cyusbs->intf_num;
+	ret = mfd_add_devices(&interface->dev, mfd_id, cyusbs23x_devs,
+				ndevs, NULL, 0, NULL);
+	if (ret != 0) {
+		dev_err(&interface->dev, "Failed to add mfd devices to core\n");
+		goto error;
+	}
+
+	return 0;
+
+error:
+	usb_set_intfdata(interface, NULL);
+	usb_put_dev(cyusbs->usb_dev);
+	kfree(cyusbs);
+
+	return ret;
+}
+
+static void cyusbs23x_disconnect(struct usb_interface *interface)
+{
+	struct cyusbs23x *cyusbs = usb_get_intfdata(interface);
+
+	mfd_remove_devices(&interface->dev);
+	usb_set_intfdata(interface, NULL);
+	usb_put_dev(cyusbs->usb_dev);
+	kfree(cyusbs);
+
+	dev_dbg(&interface->dev, "disconnected\n");
+}
+
+static struct usb_driver cyusbs23x_usb_driver = {
+	.name           = "cyusbs23x",
+	.probe          = cyusbs23x_probe,
+	.disconnect     = cyusbs23x_disconnect,
+	.id_table       = cyusbs23x_usb_table,
+};
+
+module_usb_driver(cyusbs23x_usb_driver);
+
+MODULE_AUTHOR("Rajaram Regupathy <rera@xxxxxxxxxxx>");
+MODULE_AUTHOR("Muthu Mani <muth@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("CYUSBS23x driver v0.1");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/cyusbs23x.h b/include/linux/mfd/cyusbs23x.h
new file mode 100644
index 0000000..0b71825
--- /dev/null
+++ b/include/linux/mfd/cyusbs23x.h
@@ -0,0 +1,57 @@
+/*
+ * Cypress USB-Serial Bridge Controller definitions
+ *
+ * Copyright (c) 2014 Cypress Semiconductor Corporation.
+ *
+ * Author:
+ *   Muthu Mani <muth@xxxxxxxxxxx>
+ *
+ * Additional contributors include:
+ *   Rajaram Regupathy <rera@xxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#ifndef __MFD_CYUSBS23X_H__
+#define __MFD_CYUSBS23X_H__
+
+#include <linux/types.h>
+#include <linux/usb.h>
+
+/* Structure to hold all device specific stuff */
+struct cyusbs23x {
+	struct usb_device *usb_dev;
+	struct usb_interface *usb_intf;
+	struct mutex lock;
+
+	u8 intf_num;
+	u8 bulk_in_ep_num;
+	u8 bulk_out_ep_num;
+	u8 intr_in_ep_num;
+};
+
+enum cy_vendor_cmds {
+	CY_I2C_GET_CONFIG_CMD  = 0xC4,
+	CY_I2C_SET_CONFIG_CMD  = 0xC5,
+	CY_I2C_WRITE_CMD       = 0xC6,
+	CY_I2C_READ_CMD        = 0xC7,
+	CY_I2C_GET_STATUS_CMD  = 0xC8,
+	CY_I2C_RESET_CMD       = 0xC9,
+	CY_GPIO_GET_CONFIG_CMD = 0xD8,
+	CY_GPIO_SET_CONFIG_CMD = 0xD9,
+	CY_GPIO_GET_VALUE_CMD  = 0xDA,
+	CY_GPIO_SET_VALUE_CMD  = 0xDB,
+};
+
+enum cy_scb_modes {
+	CY_USBS_SCB_DISABLED = 0,
+	CY_USBS_SCB_UART = 1,
+	CY_USBS_SCB_SPI = 2,
+	CY_USBS_SCB_I2C = 3
+};
+
+#define CY_SCB_INDEX_POS      15
+
+#endif /* __MFD_CYUSBS23X_H__ */
-- 
1.8.3.2

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