This patch adds support for the I2C interface of the Devantech USB-ISS Multifunction adapter. Signed-off-by: Guenter Roeck <guenter.roeck@xxxxxxxxxxxx> --- The driver has one problem: It competes with the cdc_acm driver for device access. Copying the usb mailing list in the hope that someone can tell me if there is a way to prevent this from happening. Documentation/i2c/busses/i2c-devantech-iss | 31 ++ drivers/i2c/busses/Kconfig | 10 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-devantech-iss.c | 495 ++++++++++++++++++++++++++++ 4 files changed, 537 insertions(+), 0 deletions(-) create mode 100644 Documentation/i2c/busses/i2c-devantech-iss create mode 100644 drivers/i2c/busses/i2c-devantech-iss.c diff --git a/Documentation/i2c/busses/i2c-devantech-iss b/Documentation/i2c/busses/i2c-devantech-iss new file mode 100644 index 0000000..f8199fd --- /dev/null +++ b/Documentation/i2c/busses/i2c-devantech-iss @@ -0,0 +1,31 @@ +Kernel driver i2c-devantech-iss + +Supported adapters: + * Devantech USB-ISS Multifunction USB Communications Module + Documentation: + http://www.robot-electronics.co.uk/htm/usb_iss_tech.htm + +Author: Guenter Roeck <guenter.roeck@xxxxxxxxxxxx> + + +Description +----------- + +This is the driver for the Devantech USB-ISS Multifunction USB Communications +Module. + +The USB-ISS Multifunction USB Communications Module provides an interface +to I2C, SPI, Serial port, and general purpose Analogue Input or Digital I/O. +The module is powered from USB. + +The driver only supports the I2C interface of USB-ISS. The driver does not use +interrupts. + +Clock stretching is supported for bus frequencies of 100,000 Hz and above. + + +Module parameters +----------------- + +* frequency: I2C bus frequency in Hz + Supported frequencies are 20,000, 50,000, 100,000, 400,000, and 1,000,000 Hz. diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 230601e..0bffacd 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -676,6 +676,16 @@ config I2C_EG20T comment "External I2C/SMBus adapter drivers" +config I2C_DEVANTECH + tristate "Devantech USB-ISS" + select I2C_SMBUS + help + This supports the I2C interface of the Devantech USB-ISS Multifunction + Communications Module. + + This driver can also be built as a module. If so, the module + will be called i2c-devantech-iss. + config I2C_PARPORT tristate "Parallel port adapter" depends on PARPORT diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 3878c95..5ecec28 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -67,6 +67,7 @@ obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o obj-$(CONFIG_I2C_EG20T) += i2c-eg20t.o # External I2C/SMBus adapter drivers +obj-$(CONFIG_I2C_DEVANTECH) += i2c-devantech-iss.o obj-$(CONFIG_I2C_PARPORT) += i2c-parport.o obj-$(CONFIG_I2C_PARPORT_LIGHT) += i2c-parport-light.o obj-$(CONFIG_I2C_TAOS_EVM) += i2c-taos-evm.o diff --git a/drivers/i2c/busses/i2c-devantech-iss.c b/drivers/i2c/busses/i2c-devantech-iss.c new file mode 100644 index 0000000..b14daa6 --- /dev/null +++ b/drivers/i2c/busses/i2c-devantech-iss.c @@ -0,0 +1,495 @@ +/* + * Driver for the Devantech USB-ISS Multifunction Communications Module + * + * Copyright (c) 2011 Ericsson AB + * + * Derived from: + * i2c-diolan-u2c.c + * Copyright (c) 2010-2011 Ericsson AB + * + * 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/errno.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/usb.h> +#include <linux/i2c.h> + +#define DRIVER_NAME "i2c-devantech-iss" + +#define USB_VENDOR_ID_DEVANTECH 0x04d8 +#define USB_DEVICE_ID_ISS 0xffee + +/* commands */ +#define ISS_CMD_I2C_DIRECT 0x57 /* Custom I2C sequence */ +#define ISS_CMD_I2C_INTERNAL 0x5a /* internal commands */ + +/* direct commands */ +#define ISS_I2C_START 0x01 +#define ISS_I2C_RESTART 0x02 +#define ISS_I2C_STOP 0x03 +#define ISS_I2C_NACK 0x04 +#define ISS_I2C_READ(n) (0x20 + (n) - 1) +#define ISS_I2C_WRITE(n) (0x30 + (n) - 1) + +/* internal commands */ +#define ISS_GET_VERSION 0x01 +#define ISS_MODE 0x02 +#define ISS_GET_SERIAL 0x03 + +/* modes */ +#define ISS_MODE_I2C_S_20KHZ 0x20 /* I2C, SW (bitbang), 20 kHz clock */ +#define ISS_MODE_I2C_S_50KHZ 0x30 /* I2C, SW (bitbang), 50 kHz clock */ +#define ISS_MODE_I2C_S_100KHZ 0x40 /* I2C, SW (bitbang), 100 kHz clock */ +#define ISS_MODE_I2C_S_400KHZ 0x50 /* I2C, SW (bitbang), 400 kHz clock */ +#define ISS_MODE_I2C_H_100KHZ 0x60 /* I2C, HW (PIC), 100 kHz clock */ +#define ISS_MODE_I2C_H_400KHZ 0x70 /* I2C, HW (PIC), 400 kHz clock */ +#define ISS_MODE_I2C_H_1000KHZ 0x80 /* I2C, HW (PIC), 1000 kHz clock */ + +/* response codes */ + +#define ISS_RESP_ACK 0xff +#define ISS_RESP_NACK 0x00 + +#define ISS_RESP_OK 0x00 +#define ISS_RESP_DEV_ERROR 0x01 +#define ISS_RESP_OVERFLOW 0x02 +#define ISS_RESP_UNDERFLOW 0x03 +#define ISS_RESP_UNKNOWN_CMD 0x04 + +#define ISS_USB_TIMEOUT 100 /* in ms */ + +#define ISS_MAX_TRANSFER_LEN 60 + +/* Structure to hold all of our device specific stuff */ +struct i2c_devantech_iss { + u8 buffer[ISS_MAX_TRANSFER_LEN];/* rx and tx buffer */ + struct usb_interface *usb_if; /* device data interface */ + struct usb_interface *interface;/* device control interface */ + struct usb_device *usb_dev; /* the usb device for this interface */ + struct i2c_adapter adapter; /* i2c related things */ + int ep_out, ep_in; +}; + +static uint frequency = 100000; /* I2C clock frequency in Hz */ +module_param(frequency, uint, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(frequency, "I2C clock frequency in hertz"); + +static struct usb_driver devantech_iss_driver; + +/* usb layer */ + +/* Send command to device, and get response. */ +static int devantech_usb_transfer(struct i2c_devantech_iss *dev, int len) +{ + int ret, actual; + + if (len <= 0 || len > ISS_MAX_TRANSFER_LEN) + return -EINVAL; + + ret = usb_bulk_msg(dev->usb_dev, + usb_sndbulkpipe(dev->usb_dev, dev->ep_out), + dev->buffer, len, &actual, + ISS_USB_TIMEOUT); + + if (!ret) { + ret = usb_bulk_msg(dev->usb_dev, + usb_rcvbulkpipe(dev->usb_dev, dev->ep_in), + dev->buffer, sizeof(dev->buffer), + &actual, ISS_USB_TIMEOUT); + if (!ret && actual > 0) + ret = actual; + } + return ret; +} + +static int devantech_set_speed(struct i2c_devantech_iss *dev, int speed) +{ + int ret; + + dev->buffer[0] = ISS_CMD_I2C_INTERNAL; + dev->buffer[1] = ISS_MODE; + dev->buffer[2] = speed; + dev->buffer[3] = 0x04; + + ret = devantech_usb_transfer(dev, 4); + if (ret < 0) + return ret; + if (!dev->buffer[0]) + return -EINVAL; + return 0; +} + +static void devantech_fw_version(struct i2c_devantech_iss *dev) +{ + int ret; + + dev->buffer[0] = ISS_CMD_I2C_INTERNAL; + dev->buffer[1] = ISS_GET_VERSION; + + ret = devantech_usb_transfer(dev, 2); + if (ret >= 3) + dev_info(&dev->interface->dev, + "Devantech USB-ISS firmware version %u.%u\n", + dev->buffer[0], dev->buffer[1]); + else + dev_err(&dev->interface->dev, + "Failed to get firmware version, error %d\n", ret); +} + +static void devantech_get_serial(struct i2c_devantech_iss *dev) +{ + int ret; + + dev->buffer[0] = ISS_CMD_I2C_INTERNAL; + dev->buffer[1] = ISS_GET_SERIAL; + + ret = devantech_usb_transfer(dev, 2); + if (ret >= 8) { + dev->buffer[ret] = '\0'; + dev_info(&dev->interface->dev, + "Devantech USS-ISS serial number %s\n", dev->buffer); + } else { + dev_err(&dev->interface->dev, + "Failed to get serial number, error %d\n", ret); + } +} + +static int devantech_init(struct i2c_devantech_iss *dev) +{ + int speed; + + /* + * Software (bit-bang) I2C implementation does not support I2C clock + * stretching, at least not with firmware version 7.2. The PIC hardware + * implementation supports it, so select the hardware protocol if + * available for a given bus speed. + * If the bus speed is not configured or set to 0, select 100kHz. + */ + if (frequency >= 1000000) { + speed = ISS_MODE_I2C_H_1000KHZ; + frequency = 1000000; + } else if (frequency >= 400000) { + speed = ISS_MODE_I2C_H_400KHZ; + frequency = 400000; + } else if (frequency >= 100000 || frequency == 0) { + speed = ISS_MODE_I2C_H_100KHZ; + frequency = 100000; + } else if (frequency >= 50000) { + speed = ISS_MODE_I2C_S_50KHZ; + frequency = 50000; + } else { + speed = ISS_MODE_I2C_S_20KHZ; + frequency = 20000; + } + + dev_info(&dev->interface->dev, + "Devantech USB-ISS at USB bus %03d address %03d speed %d Hz\n", + dev->usb_dev->bus->busnum, dev->usb_dev->devnum, frequency); + + devantech_fw_version(dev); + devantech_get_serial(dev); + + return devantech_set_speed(dev, speed); +} + +/* i2c layer */ + +static int devantech_usb_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, + int num) +{ + struct i2c_devantech_iss *dev = i2c_get_adapdata(adapter); + struct i2c_msg *pmsg = NULL; + int i, j, len, rlen; + int ret; + + len = 0; + dev->buffer[len++] = ISS_CMD_I2C_DIRECT; + dev->buffer[len++] = ISS_I2C_START; + + for (i = 0; i < num; i++) { + pmsg = &msgs[i]; + if (i) + dev->buffer[len++] = ISS_I2C_RESTART; + + if (pmsg->flags & I2C_M_RD) { + dev->buffer[len++] = ISS_I2C_WRITE(1); + dev->buffer[len++] = (pmsg->addr << 1) | 1; + if (pmsg->flags & I2C_M_RECV_LEN) { + /* + * Block read returns receive length in 1st + * byte. We must read up to 33 bytes of data + * (len + 32) to avoid adapter hangup. + */ + dev->buffer[len++] = ISS_I2C_READ(16); + dev->buffer[len++] = ISS_I2C_READ(16); + dev->buffer[len++] = ISS_I2C_NACK; + dev->buffer[len++] = ISS_I2C_READ(1); + } else { + rlen = pmsg->len; + /* + * repeat read sequence until done or out of + * buffer + */ + if (rlen > ISS_MAX_TRANSFER_LEN - 8) + rlen = ISS_MAX_TRANSFER_LEN - 8; + while (rlen > 16) { + dev->buffer[len++] = ISS_I2C_READ(16); + rlen -= 16; + } + if (rlen > 1) + dev->buffer[len++] + = ISS_I2C_READ(rlen - 1); + dev->buffer[len++] = ISS_I2C_NACK; + dev->buffer[len++] = ISS_I2C_READ(1); + } + } else { + dev->buffer[len++] = ISS_I2C_WRITE(1); + dev->buffer[len++] = pmsg->addr << 1; + /* Repeat write sequence until done */ + for (rlen = 0; rlen < pmsg->len; rlen += 16) { + int clen = min(pmsg->len - rlen, 16); + /* + * Make sure we have enough buffer space. We + * need two additional bytes, one for the write + * command itself and one for the STOP command. + */ + if (len + clen > ISS_MAX_TRANSFER_LEN - 2) { + ret = -EINVAL; + goto error; + } + dev->buffer[len++] = ISS_I2C_WRITE(clen); + for (j = 0; j < clen; j++) + dev->buffer[len++] + = pmsg->buf[rlen + j]; + } + } + } + dev->buffer[len++] = ISS_I2C_STOP; + + ret = devantech_usb_transfer(dev, len); + if (ret < 0) + goto error; + + if (ret < 2) { + ret = -EIO; + goto error; + } + + if (dev->buffer[0] == ISS_RESP_NACK) { + ret = dev->buffer[1] == ISS_RESP_DEV_ERROR ? -ENXIO : -EIO; + goto error; + } + + /* + * Copy received data back into receive buffer. pmsg points to it. + */ + if (pmsg->flags & I2C_M_RD) { + if (pmsg->flags & I2C_M_RECV_LEN) { + rlen = dev->buffer[2]; + if (rlen == 0 || rlen > I2C_SMBUS_BLOCK_MAX || + rlen > ret - 2) { + ret = -EPROTO; + goto error; + } + pmsg->len += rlen; + len = pmsg->len; + } else { + len = ret - 2; + } + for (i = 0; i < len; i++) + pmsg->buf[i] = dev->buffer[i + 2]; + } + ret = 0; +error: + return ret; +} + +/* + * Return list of supported functionality. + */ +static u32 devantech_usb_func(struct i2c_adapter *a) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | + I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL; +} + +static const struct i2c_algorithm devantech_usb_algorithm = { + .master_xfer = devantech_usb_xfer, + .functionality = devantech_usb_func, +}; + +/* device layer */ + +static const struct usb_device_id devantech_iss_table[] = { + { USB_DEVICE(USB_VENDOR_ID_DEVANTECH, USB_DEVICE_ID_ISS) }, + { } +}; + +MODULE_DEVICE_TABLE(usb, devantech_iss_table); + +static void devantech_iss_free(struct i2c_devantech_iss *dev) +{ + usb_put_dev(dev->usb_dev); + kfree(dev); +} + +static int devantech_iss_probe(struct usb_interface *interface, + const struct usb_device_id *id) +{ + struct i2c_devantech_iss *dev; + int ret; + struct usb_interface *usb_if; + struct usb_host_endpoint *ep_out, *ep_in; + + /* allocate memory for our device state and initialize it */ + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (dev == NULL) { + dev_err(&interface->dev, "no memory for device state\n"); + ret = -ENOMEM; + goto error; + } + + dev->usb_dev = usb_get_dev(interface_to_usbdev(interface)); + dev->interface = interface; + + /* setup i2c adapter description */ + dev->adapter.owner = THIS_MODULE; + dev->adapter.class = I2C_CLASS_HWMON; + dev->adapter.algo = &devantech_usb_algorithm; + i2c_set_adapdata(&dev->adapter, dev); + + snprintf(dev->adapter.name, sizeof(dev->adapter.name), + DRIVER_NAME " at bus %03d device %03d", + dev->usb_dev->bus->busnum, dev->usb_dev->devnum); + + dev->adapter.dev.parent = &dev->interface->dev; + + /* Only accept probe on control interface */ + usb_if = usb_ifnum_to_if(dev->usb_dev, 0); + if (usb_if != interface) { + dev_err(&interface->dev, "not on control interface\n"); + ret = -ENODEV; + goto error_free; + } + + usb_if = usb_ifnum_to_if(dev->usb_dev, 1); + if (!usb_if) { + dev_err(&interface->dev, "no USB interface\n"); + ret = -ENODEV; + goto error_free; + } + if (usb_interface_claimed(usb_if)) { + dev_err(&interface->dev, "USB interface busy\n"); + ret = -EBUSY; + goto error_free; + } + if (usb_if->cur_altsetting->desc.bNumEndpoints < 2) { + dev_err(&interface->dev, + "insufficient number of USB endpoints\n"); + ret = -EINVAL; + goto error_free; + } + + ep_out = &usb_if->cur_altsetting->endpoint[0]; + ep_in = &usb_if->cur_altsetting->endpoint[1]; + if (!ep_out || !ep_in) { + dev_err(&interface->dev, "missing USB endpoints\n"); + ret = -EINVAL; + goto error_free; + } + dev->ep_out = ep_out->desc.bEndpointAddress; + dev->ep_in = ep_in->desc.bEndpointAddress; + dev->usb_if = usb_get_intf(usb_if); + + /* + * We need to claim the data interface to prevent other drivers + * from accessing and registering it. + */ + ret = usb_driver_claim_interface(&devantech_iss_driver, + dev->usb_if, dev); + if (ret < 0) { + dev_err(&usb_if->dev, "failed to claim interface\n"); + goto error_put; + } + + /* save our data pointer in this interface device */ + usb_set_intfdata(interface, dev); + + /* initialize devantech i2c interface */ + ret = devantech_init(dev); + if (ret < 0) { + dev_err(&interface->dev, "failed to initialize adapter\n"); + goto error_release; + } + + /* and finally attach to i2c layer */ + ret = i2c_add_adapter(&dev->adapter); + if (ret < 0) { + dev_err(&interface->dev, "failed to add I2C adapter\n"); + goto error_release; + } + + dev_info(&interface->dev, "connected\n"); + return 0; + +error_release: + usb_set_intfdata(interface, NULL); + usb_set_intfdata(dev->usb_if, NULL); + usb_driver_release_interface(&devantech_iss_driver, dev->usb_if); +error_put: + usb_put_intf(dev->usb_if); +error_free: + devantech_iss_free(dev); +error: + return ret; +} + +static void devantech_iss_disconnect(struct usb_interface *interface) +{ + struct i2c_devantech_iss *dev = usb_get_intfdata(interface); + struct usb_host_interface *alt = interface->cur_altsetting; + + if (alt->desc.bInterfaceNumber) + return; + + i2c_del_adapter(&dev->adapter); + usb_set_intfdata(interface, NULL); + usb_set_intfdata(dev->usb_if, NULL); + usb_driver_release_interface(&devantech_iss_driver, dev->usb_if); + usb_put_intf(dev->usb_if); + devantech_iss_free(dev); + + dev_info(&interface->dev, "disconnected\n"); +} + +static struct usb_driver devantech_iss_driver = { + .name = DRIVER_NAME, + .probe = devantech_iss_probe, + .disconnect = devantech_iss_disconnect, + .id_table = devantech_iss_table, +}; + +static int __init devantech_iss_init(void) +{ + /* register this driver with the USB subsystem */ + return usb_register(&devantech_iss_driver); +} + +static void __exit devantech_iss_exit(void) +{ + /* deregister this driver with the USB subsystem */ + usb_deregister(&devantech_iss_driver); +} + +module_init(devantech_iss_init); +module_exit(devantech_iss_exit); + +MODULE_AUTHOR("Guenter Roeck <guenter.roeck@xxxxxxxxxxxx>"); +MODULE_DESCRIPTION(DRIVER_NAME " driver"); +MODULE_LICENSE("GPL"); -- 1.7.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
