[PATCH v4 1/3] mfd: add support for Cypress CYUSBS234 USB Serial Bridge controller

From: Muthu Mani
Date: Fri Nov 28 2014 - 11:54:54 EST

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>
---
Changes since v3:
* Added devm_* allocation function
* Added vendor commands to read configuration info

Changes since v2:
* Used auto mfd id to support multiple devices
* Cleaned up the code

Changes since v1:
* Identified different serial interface and loaded correct cell driver
* Formed a mfd id to support multiple devices
* Removed unused platform device

drivers/mfd/Kconfig | 12 +++
drivers/mfd/Makefile | 1 +
drivers/mfd/cyusbs23x.c | 167 ++++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/cyusbs23x.h | 56 ++++++++++++++
4 files changed, 236 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 1456ea7..504d125 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 8bd54b1..81c0f87 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_MFD_SPMI_PMIC) += qcom-spmi-pmic.o
diff --git a/drivers/mfd/cyusbs23x.c b/drivers/mfd/cyusbs23x.c
new file mode 100644
index 0000000..bdde42f
--- /dev/null
+++ b/drivers/mfd/cyusbs23x.c
@@ -0,0 +1,167 @@
+/*
+ * 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>
+
+/* Serial interfaces (I2C, SPI, UART) differ in interface subclass */
+enum cy_scb_modes {
+ CY_USBS_SCB_DISABLED = 0,
+ CY_USBS_SCB_UART = 1,
+ CY_USBS_SCB_SPI = 2,
+ CY_USBS_SCB_I2C = 3
+};
+
+static const struct usb_device_id cyusbs23x_usb_table[] = {
+ { USB_DEVICE(0x04b4, 0x0004) }, /* Cypress Semiconductor CYUSBS234 */
+ { }
+};
+
+MODULE_DEVICE_TABLE(usb, cyusbs23x_usb_table);
+
+static const struct mfd_cell cyusbs23x_i2c_gpio_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;
+
+ iface_desc = interface->cur_altsetting;
+
+ for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+
+ 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 intr_in=%d, bulk_in=%d, bulk_out=%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) {
+ dev_err(&interface->dev, "%s invalid endpoints\n", __func__);
+ 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, ndevs = 0;
+
+ cyusbs = devm_kzalloc(&interface->dev, sizeof(*cyusbs), GFP_KERNEL);
+ if (!cyusbs)
+ return -ENOMEM;
+
+ ret = update_ep_details(interface, cyusbs);
+ if (ret)
+ return -ENODEV;
+
+ /* Serial interfaces (I2C, SPI, UART) differ in interface subclass */
+ switch (interface->cur_altsetting->desc.bInterfaceSubClass) {
+ case CY_USBS_SCB_I2C:
+ dev_info(&interface->dev, "using I2C interface\n");
+ cyusbs23x_devs = cyusbs23x_i2c_gpio_devs;
+ ndevs = ARRAY_SIZE(cyusbs23x_i2c_gpio_devs);
+ break;
+ default:
+ dev_err(&interface->dev, "unsupported subclass\n");
+ return -ENODEV;
+ }
+
+ cyusbs->usb_dev = usb_get_dev(interface_to_usbdev(interface));
+ cyusbs->usb_intf = interface;
+ cyusbs->intf_num = interface->cur_altsetting->desc.bInterfaceNumber;
+ usb_set_intfdata(interface, cyusbs);
+
+ ret = mfd_add_devices(&interface->dev, PLATFORM_DEVID_AUTO,
+ cyusbs23x_devs, ndevs, NULL, 0, NULL);
+ if (ret) {
+ dev_err(&interface->dev, "Failed to register devices\n");
+ goto error;
+ }
+
+ dev_info(&interface->dev, "registered MFD device\n");
+ return 0;
+
+error:
+ usb_put_dev(cyusbs->usb_dev);
+
+ return ret;
+}
+
+static void cyusbs23x_disconnect(struct usb_interface *interface)
+{
+ struct cyusbs23x *cyusbs = usb_get_intfdata(interface);
+
+ mfd_remove_devices(&interface->dev);
+ usb_put_dev(cyusbs->usb_dev);
+}
+
+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("Cypress CYUSBS23x MFD core driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/cyusbs23x.h b/include/linux/mfd/cyusbs23x.h
new file mode 100644
index 0000000..534fcf7
--- /dev/null
+++ b/include/linux/mfd/cyusbs23x.h
@@ -0,0 +1,56 @@
+/*
+ * 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;
+
+ u8 intf_num;
+ u8 bulk_in_ep_num;
+ u8 bulk_out_ep_num;
+ u8 intr_in_ep_num;
+};
+
+enum cy_usbs_vendor_cmds {
+ CY_DEV_CMD_READ_CONFIG = 0xB5,
+ 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,
+ CY_DEV_ENABLE_CONFIG_READ_CMD = 0xE2
+};
+
+/* SCB index shift */
+#define CY_SCB_INDEX_SHIFT 15
+
+#define CY_USBS_CTRL_XFER_TIMEOUT 2000
+#define CY_USBS_BULK_XFER_TIMEOUT 5000
+#define CY_USBS_INTR_XFER_TIMEOUT 5000
+
+#endif /* __MFD_CYUSBS23X_H__ */
--
1.8.3.2


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