i2c: Add bus driver for for OSIF USB i2c device.

OSIF, Open Source InterFace, is a USB based i2c bus master.  The
origional design was based on i2c-tiny-usb, but more modern versions
of the firmware running on the MegaAVR microcontroller use a different
protocol over the USB. This code is based on Barry Carter
<barry.carter@gmail.com> driver.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 98a3f1f..6bcdea5 100644 (file)
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -874,6 +874,16 @@ config I2C_PARPORT_LIGHT
          This support is also available as a module.  If so, the module
          will be called i2c-parport-light.
 
+config I2C_ROBOTFUZZ_OSIF
+       tristate "RobotFuzz Open Source InterFace USB adapter"
+       depends on USB
+       help
+         If you say yes to this option, support will be included for the
+         RobotFuzz Open Source InterFace USB to I2C interface.
+
+         This driver can also be built as a module.  If so, the module
+         will be called i2c-osif.
+
 config I2C_TAOS_EVM
        tristate "TAOS evaluation module"
        depends on TTY

diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index dca041b..a08931f 100644 (file)
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -84,6 +84,7 @@ obj-$(CONFIG_I2C_RCAR)                += i2c-rcar.o
 obj-$(CONFIG_I2C_DIOLAN_U2C)   += i2c-diolan-u2c.o
 obj-$(CONFIG_I2C_PARPORT)      += i2c-parport.o
 obj-$(CONFIG_I2C_PARPORT_LIGHT)        += i2c-parport-light.o
+obj-$(CONFIG_I2C_ROBOTFUZZ_OSIF)       += i2c-robotfuzz-osif.o
 obj-$(CONFIG_I2C_TAOS_EVM)     += i2c-taos-evm.o
 obj-$(CONFIG_I2C_TINY_USB)     += i2c-tiny-usb.o
 obj-$(CONFIG_I2C_VIPERBOARD)   += i2c-viperboard.o

diff --git a/drivers/i2c/busses/i2c-robotfuzz-osif.c b/drivers/i2c/busses/i2c-robotfuzz-osif.c
new file mode 100644 (file)
index 0000000..ced9c6a
--- /dev/null
+++ b/drivers/i2c/busses/i2c-robotfuzz-osif.c
@@ -0,0 +1,202 @@
+/*
+ * Driver for RobotFuzz OSIF
+ *
+ * Copyright (c) 2013 Andrew Lunn <andrew@lunn.ch>
+ * Copyright (c) 2007 Barry Carter <Barry.Carter@robotfuzz.com>
+ *
+ * Based on the i2c-tiny-usb by
+ *
+ * Copyright (C) 2006 Til Harbaum (Till@Harbaum.org)
+ *
+ *     This program is free software; you can redistribute it and/or
+ *     modify it under the terms of the GNU General Public License as
+ *     published by the Free Software Foundation, version 2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+
+#define OSIFI2C_READ           20
+#define OSIFI2C_WRITE          21
+#define OSIFI2C_STOP           22
+#define OSIFI2C_STATUS         23
+#define OSIFI2C_SET_BIT_RATE   24
+
+#define STATUS_ADDRESS_ACK     0
+#define STATUS_ADDRESS_NAK     2
+
+struct osif_priv {
+       struct usb_device *usb_dev;
+       struct usb_interface *interface;
+       struct i2c_adapter adapter;
+       unsigned char status;
+};
+
+static int osif_usb_read(struct i2c_adapter *adapter, int cmd,
+                        int value, int index, void *data, int len)
+{
+       struct osif_priv *priv = adapter->algo_data;
+
+       return usb_control_msg(priv->usb_dev, usb_rcvctrlpipe(priv->usb_dev, 0),
+                              cmd, USB_TYPE_VENDOR | USB_RECIP_INTERFACE |
+                              USB_DIR_IN, value, index, data, len, 2000);
+}
+
+static int osif_usb_write(struct i2c_adapter *adapter, int cmd,
+                         int value, int index, void *data, int len)
+{
+
+       struct osif_priv *priv = adapter->algo_data;
+
+       return usb_control_msg(priv->usb_dev, usb_sndctrlpipe(priv->usb_dev, 0),
+                              cmd, USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+                              value, index, data, len, 2000);
+}
+
+static int osif_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
+                        int num)
+{
+       struct osif_priv *priv = adapter->algo_data;
+       struct i2c_msg *pmsg;
+       int ret = 0;
+       int i, cmd;
+
+       for (i = 0; ret >= 0 && i < num; i++) {
+               pmsg = &msgs[i];
+
+               if (pmsg->flags & I2C_M_RD) {
+                       cmd = OSIFI2C_READ;
+
+                       ret = osif_usb_read(adapter, cmd, pmsg->flags,
+                                           pmsg->addr, pmsg->buf,
+                                           pmsg->len);
+                       if (ret != pmsg->len) {
+                               dev_err(&adapter->dev, "failure reading data\n");
+                               return -EREMOTEIO;
+                       }
+               } else {
+                       cmd = OSIFI2C_WRITE;
+
+                       ret = osif_usb_write(adapter, cmd, pmsg->flags,
+                                            pmsg->addr, pmsg->buf, pmsg->len);
+                       if (ret != pmsg->len) {
+                               dev_err(&adapter->dev, "failure writing data\n");
+                               return -EREMOTEIO;
+                       }
+               }
+
+               ret = osif_usb_read(adapter, OSIFI2C_STOP, 0, 0, NULL, 0);
+               if (ret) {
+                       dev_err(&adapter->dev, "failure sending STOP\n");
+                       return -EREMOTEIO;
+               }
+
+               /* read status */
+               ret = osif_usb_read(adapter, OSIFI2C_STATUS, 0, 0,
+                                   &priv->status, 1);
+               if (ret != 1) {
+                       dev_err(&adapter->dev, "failure reading status\n");
+                       return -EREMOTEIO;
+               }
+
+               if (priv->status != STATUS_ADDRESS_ACK) {
+                       dev_dbg(&adapter->dev, "status = %d\n", priv->status);
+                       return -EREMOTEIO;
+               }
+       }
+
+       return i;
+}
+
+static u32 osif_func(struct i2c_adapter *adapter)
+{
+       return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm osif_algorithm = {
+       .master_xfer    = osif_xfer,
+       .functionality  = osif_func,
+};
+
+#define USB_OSIF_VENDOR_ID     0x1964
+#define USB_OSIF_PRODUCT_ID    0x0001
+
+static struct usb_device_id osif_table[] = {
+       { USB_DEVICE(USB_OSIF_VENDOR_ID, USB_OSIF_PRODUCT_ID) },
+       { }
+};
+MODULE_DEVICE_TABLE(usb, osif_table);
+
+static int osif_probe(struct usb_interface *interface,
+                            const struct usb_device_id *id)
+{
+       int ret;
+       struct osif_priv *priv;
+       u16 version;
+
+       priv = devm_kzalloc(&interface->dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       priv->usb_dev = usb_get_dev(interface_to_usbdev(interface));
+       priv->interface = interface;
+
+       usb_set_intfdata(interface, priv);
+
+       priv->adapter.owner = THIS_MODULE;
+       priv->adapter.class = I2C_CLASS_HWMON;
+       priv->adapter.algo = &osif_algorithm;
+       priv->adapter.algo_data = priv;
+       snprintf(priv->adapter.name, sizeof(priv->adapter.name),
+                "OSIF at bus %03d device %03d",
+                priv->usb_dev->bus->busnum, priv->usb_dev->devnum);
+
+       /*
+        * Set bus frequency. The frequency is:
+        * 120,000,000 / ( 16 + 2 * div * 4^prescale).
+        * Using dev = 52, prescale = 0 give 100KHz */
+       ret = osif_usb_read(&priv->adapter, OSIFI2C_SET_BIT_RATE, 52, 0,
+                           NULL, 0);
+       if (ret) {
+               dev_err(&interface->dev, "failure sending bit rate");
+               usb_put_dev(priv->usb_dev);
+               return ret;
+       }
+
+       i2c_add_adapter(&(priv->adapter));
+
+       version = le16_to_cpu(priv->usb_dev->descriptor.bcdDevice);
+       dev_info(&interface->dev,
+                "version %x.%02x found at bus %03d address %03d",
+                version >> 8, version & 0xff,
+                priv->usb_dev->bus->busnum, priv->usb_dev->devnum);
+
+       return 0;
+}
+
+static void osif_disconnect(struct usb_interface *interface)
+{
+       struct osif_priv *priv = usb_get_intfdata(interface);
+
+       i2c_del_adapter(&(priv->adapter));
+       usb_set_intfdata(interface, NULL);
+       usb_put_dev(priv->usb_dev);
+}
+
+static struct usb_driver osif_driver = {
+       .name           = "RobotFuzz Open Source InterFace, OSIF",
+       .probe          = osif_probe,
+       .disconnect     = osif_disconnect,
+       .id_table       = osif_table,
+};
+
+module_usb_driver(osif_driver);
+
+MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
+MODULE_AUTHOR("Barry Carter <barry.carter@robotfuzz.com>");
+MODULE_DESCRIPTION("RobotFuzz OSIF driver");
+MODULE_LICENSE("GPL v2");