Signed-off-by: Guenter Roeck <guenter.roeck@xxxxxxxxxxxx>
---
v3:
- Round frequency configuration down (instead of rounding to closest value)
- Simplify diolan_usb_transfer() a bit
- Introduce diolan_write_cmd() to check if a write is needed and execute it if
so.
- diolan_fw_version() and diolan_get_serial() no longer return errors.
- Change "Out of memory" error message to "no memory for device state".
- Display error message if diolan_init() fails.
- Merged patches into a single patch.
v2:
- Moved receive and transmit buffers to allocated driver memory
- diolan_usb_transfer() no longer requires buffer and length arguments
- Pass "struct i2c_diolan_u2c *" instead of "struct i2c_adapter *" to many of
the internal usb access functions.
- Introduced diolan_usb_cmd(), diolan_usb_cmd_data(), and diolan_usb_cmd_data2()
as front-end functions for actual commands.
- Function prefix is now diolan_ for all functions.
- Removed diolan_scan().
- Fixed race conditions in diolan_u2c_probe().
- Use i2c_{set,get}_adapdata instead of misusing adapter.algo_data.
- Driver name is now i2c-diolan-u2c (instead of i2c-u2c-usb).
- Added support for "frequency" module parameter to set i2c clock frequency
- Enabled I2C clock stretching support
- Support sending multiple commands in single usb transfer
- Several other minor changes to address review comments.
MAINTAINERS | 6 +
drivers/i2c/busses/Kconfig | 10 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-diolan-u2c.c | 530 +++++++++++++++++++++++++++++++++++
4 files changed, 547 insertions(+), 0 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-diolan-u2c.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 1af022e..12b0be3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2089,6 +2089,12 @@ F: Documentation/serial/digiepca.txt
F: drivers/char/epca*
F: drivers/char/digi*
+DIOLAN U2C-12 I2C DRIVER
+M: Guenter Roeck <guenter.roeck@xxxxxxxxxxxx>
+L: linux-i2c@xxxxxxxxxxxxxxx
+S: Maintained
+F: drivers/i2c/busses/i2c-diolan-u2c.c
+
DIRECTORY NOTIFICATION (DNOTIFY)
M: Eric Paris <eparis@xxxxxxxxxxxxxx>
S: Maintained
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 113505a..30f8dbd 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -648,6 +648,16 @@ config I2C_EG20T
comment "External I2C/SMBus adapter drivers"
+config I2C_DIOLAN_U2C
+ tristate "Diolan U2C-12 USB adapter"
+ depends on USB
+ help
+ If you say yes to this option, support will be included for Diolan
+ U2C-12, a USB to I2C interface.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-diolan-u2c.
+
config I2C_PARPORT
tristate "Parallel port adapter"
depends on PARPORT
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 9d2d0ec..3c630b7 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -64,6 +64,7 @@ obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
obj-$(CONFIG_I2C_EG20T) += i2c-eg20t.o
# External I2C/SMBus adapter drivers
+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_TAOS_EVM) += i2c-taos-evm.o
diff --git a/drivers/i2c/busses/i2c-diolan-u2c.c b/drivers/i2c/busses/i2c-diolan-u2c.c
new file mode 100644
index 0000000..761ce1d
--- /dev/null
+++ b/drivers/i2c/busses/i2c-diolan-u2c.c
@@ -0,0 +1,530 @@
+/*
+ * Driver for the Diolan u2c-12 USB-I2C adapter
+ *
+ * Copyright (c) 2010-2011 Ericsson AB
+ *
+ * Derived from:
+ * i2c-tiny-usb.c
+ * Copyright (C) 2006-2007 Till Harbaum (Till@xxxxxxxxxxx)
+ *
+ * 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-diolan-u2c"
+
+#define USB_VENDOR_ID_DIOLAN 0x0abf
+#define USB_DEVICE_ID_DIOLAN_U2C 0x3370
+
+#define DIOLAN_OUT_EP 0x02
+#define DIOLAN_IN_EP 0x84
+
+/* commands via USB, must match command ids in the firmware */
+#define CMD_I2C_READ 0x01
+#define CMD_I2C_WRITE 0x02
+#define CMD_I2C_SCAN 0x03 /* Returns list of detected devices */
+#define CMD_I2C_RELEASE_SDA 0x04
+#define CMD_I2C_RELEASE_SCL 0x05
+#define CMD_I2C_DROP_SDA 0x06
+#define CMD_I2C_DROP_SCL 0x07
+#define CMD_I2C_READ_SDA 0x08
+#define CMD_I2C_READ_SCL 0x09
+#define CMD_GET_FW_VERSION 0x0a
+#define CMD_GET_SERIAL 0x0b
+#define CMD_I2C_START 0x0c
+#define CMD_I2C_STOP 0x0d
+#define CMD_I2C_REPEATED_START 0x0e
+#define CMD_I2C_PUT_BYTE 0x0f
+#define CMD_I2C_GET_BYTE 0x10
+#define CMD_I2C_PUT_ACK 0x11
+#define CMD_I2C_GET_ACK 0x12
+#define CMD_I2C_PUT_BYTE_ACK 0x13
+#define CMD_I2C_GET_BYTE_ACK 0x14
+#define CMD_I2C_SET_SPEED 0x1b
+#define CMD_I2C_GET_SPEED 0x1c
+#define CMD_I2C_SET_CLK_SYNC 0x24
+#define CMD_I2C_GET_CLK_SYNC 0x25
+#define CMD_I2C_SET_CLK_SYNC_TO 0x26
+#define CMD_I2C_GET_CLK_SYNC_TO 0x27
+
+#define RESP_OK 0x00
+#define RESP_FAILED 0x01
+#define RESP_BAD_MEMADDR 0x04
+#define RESP_DATA_ERR 0x05
+#define RESP_NOT_IMPLEMENTED 0x06
+#define RESP_NACK 0x07
+#define RESP_TIMEOUT 0x09
+
+#define U2C_I2C_SPEED_FAST 0 /* 400 kHz */
+#define U2C_I2C_SPEED_STD 1 /* 100 kHz */
+#define U2C_I2C_SPEED_2KHZ 242 /* 2 kHz, minimum speed */
+#define U2C_I2C_SPEED(f) ((DIV_ROUND_UP(1000000, (f)) - 10) / 2 + 1)
+
+#define U2C_I2C_FREQ_FAST 400000
+#define U2C_I2C_FREQ_STD 100000
+#define U2C_I2C_FREQ(s) (1000000 / (2 * (s - 1) + 10))
+
+#define DIOLAN_USB_TIMEOUT 100 /* in ms */
+#define DIOLAN_SYNC_TIMEOUT 10 /* in ms */
+
+#define DIOLAN_OUTBUF_LEN 128
+#define DIOLAN_FLUSH_LEN (DIOLAN_OUTBUF_LEN - 4)
+#define DIOLAN_INBUF_LEN 257 /* Maximum supported receive length */
+
+/* Structure to hold all of our device specific stuff */
+struct i2c_diolan_u2c {
+ struct usb_device *usb_dev; /* the usb device for this device */
+ struct usb_interface *interface;/* the interface for this device */
+ struct i2c_adapter adapter; /* i2c related things */
+ int olen; /* Output buffer length */
+ int ocount; /* Number of enqueued messages */
+ u8 obuffer[DIOLAN_OUTBUF_LEN]; /* output buffer */
+ u8 ibuffer[DIOLAN_INBUF_LEN]; /* input buffer */
+};
+
+static uint frequency = U2C_I2C_FREQ_STD; /* I2C clock frequency in Hz */
+
+module_param(frequency, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(frequency, "I2C clock frequency in hertz");
+
+/* usb layer */
+
+/* Send command to device, and get response. */
+static int diolan_usb_transfer(struct i2c_diolan_u2c *dev)
+{
+ int ret = 0;
+ int actual;
+ int i;
+
+ if (!dev->olen || !dev->ocount)
+ return -EINVAL;
+
+ ret = usb_bulk_msg(dev->usb_dev,
+ usb_sndbulkpipe(dev->usb_dev, DIOLAN_OUT_EP),
+ dev->obuffer, dev->olen, &actual,
+ DIOLAN_USB_TIMEOUT);
+ if (!ret) {
+ for (i = 0; i < dev->ocount; i++) {
+ int tmpret;
+
+ tmpret = usb_bulk_msg(dev->usb_dev,
+ usb_rcvbulkpipe(dev->usb_dev,
+ DIOLAN_IN_EP),
+ dev->ibuffer,
+ sizeof(dev->ibuffer), &actual,
+ DIOLAN_USB_TIMEOUT);
+ /*
+ * Stop command processing if a previous command
+ * returned an error.
+ * Note that we still need to retrieve all messages.
+ */
+ if (ret < 0)
+ continue;
+ ret = tmpret;
+ if (ret == 0 && actual > 0) {
+ switch (dev->ibuffer[actual - 1]) {
+ case RESP_NACK:
+ ret = -ENXIO;
+ break;
+ case RESP_TIMEOUT:
+ ret = -ETIMEDOUT;
+ break;
+ case RESP_OK:
+ /* strip off return code */
+ ret = actual - 1;
+ break;
+ default:
+ ret = -EIO;
+ break;
+ }
+ }
+ }
+ }
+ dev->olen = 0;
+ dev->ocount = 0;
+ return ret;
+}
+
+static int diolan_write_cmd(struct i2c_diolan_u2c *dev, bool flush)
+{
+ if (flush || dev->olen >= DIOLAN_FLUSH_LEN)
+ return diolan_usb_transfer(dev);
+ return 0;
+}
+
+/* Send command (no data) */
+static int diolan_usb_cmd(struct i2c_diolan_u2c *dev, u8 command, bool flush)
+{
+ dev->obuffer[dev->olen++] = command;
+ dev->ocount++;
+ return diolan_write_cmd(dev, flush);
+}
+
+/* Send command with one byte of data */
+static int diolan_usb_cmd_data(struct i2c_diolan_u2c *dev, u8 command, u8 data,
+ bool flush)
+{
+ dev->obuffer[dev->olen++] = command;
+ dev->obuffer[dev->olen++] = data;
+ dev->ocount++;
+ return diolan_write_cmd(dev, flush);
+}
+
+/* Send command with two bytes of data */
+static int diolan_usb_cmd_data2(struct i2c_diolan_u2c *dev, u8 command, u8 d1,
+ u8 d2, bool flush)
+{
+ dev->obuffer[dev->olen++] = command;
+ dev->obuffer[dev->olen++] = d1;
+ dev->obuffer[dev->olen++] = d2;
+ dev->ocount++;
+ return diolan_write_cmd(dev, flush);
+}
+
+/*
+ * Flush input queue.
+ * If we don't do this at startup and the controller has queued up
+ * messages which were not retrieved, it will stop responding
+ * at some point.
+ */
+static void diolan_flush_input(struct i2c_diolan_u2c *dev)
+{
+ int i;
+
+ for (i = 0; i < 10; i++) {
+ int actual = 0;
+ int ret;
+
+ ret = usb_bulk_msg(dev->usb_dev,
+ usb_rcvbulkpipe(dev->usb_dev, DIOLAN_IN_EP),
+ dev->ibuffer, sizeof(dev->ibuffer), &actual,
+ DIOLAN_USB_TIMEOUT);
+ if (ret < 0 || actual == 0)
+ break;
+ }
+ if (i == 10)
+ dev_err(&dev->interface->dev, "Failed to flush input buffer\n");
+}
+
+static int diolan_i2c_start(struct i2c_diolan_u2c *dev)
+{
+ return diolan_usb_cmd(dev, CMD_I2C_START, false);
+}
+
+static int diolan_i2c_repeated_start(struct i2c_diolan_u2c *dev)
+{
+ return diolan_usb_cmd(dev, CMD_I2C_REPEATED_START, false);
+}
+
+static int diolan_i2c_stop(struct i2c_diolan_u2c *dev)
+{
+ return diolan_usb_cmd(dev, CMD_I2C_STOP, true);
+}
+
+static int diolan_i2c_get_byte_ack(struct i2c_diolan_u2c *dev, bool ack,
+ u8 *byte)
+{
+ int ret;
+
+ ret = diolan_usb_cmd_data(dev, CMD_I2C_GET_BYTE_ACK, ack, true);
+ if (ret > 0)
+ *byte = dev->ibuffer[0];
+ else if (ret == 0)
+ ret = -EIO;
+
+ return ret;
+}
+
+static int diolan_i2c_put_byte_ack(struct i2c_diolan_u2c *dev, u8 byte)
+{
+ return diolan_usb_cmd_data(dev, CMD_I2C_PUT_BYTE_ACK, byte, false);
+}
+
+static int diolan_set_speed(struct i2c_diolan_u2c *dev, u8 speed)
+{
+ return diolan_usb_cmd_data(dev, CMD_I2C_SET_SPEED, speed, true);
+}
+
+/* Enable or disable clock synchronization (stretching) */
+static int diolan_set_clock_synch(struct i2c_diolan_u2c *dev, bool enable)
+{
+ return diolan_usb_cmd_data(dev, CMD_I2C_SET_CLK_SYNC, enable, true);
+}
+
+/* Set clock synchronization timeout in ms */
+static int diolan_set_clock_synch_timeout(struct i2c_diolan_u2c *dev, int ms)
+{
+ int to_val = ms * 10;
+
+ return diolan_usb_cmd_data2(dev, CMD_I2C_SET_CLK_SYNC_TO,
+ to_val & 0xff, (to_val >> 8) & 0xff, true);
+}
+
+static void diolan_fw_version(struct i2c_diolan_u2c *dev)
+{
+ int ret;
+
+ ret = diolan_usb_cmd(dev, CMD_GET_FW_VERSION, true);
+ if (ret >= 2)
+ dev_info(&dev->interface->dev,
+ "Diolan U2C firmware version %u.%u\n",
+ (unsigned int)dev->ibuffer[0],
+ (unsigned int)dev->ibuffer[1]);
+}
+
+static void diolan_get_serial(struct i2c_diolan_u2c *dev)
+{
+ int ret;
+ u32 serial;
+
+ ret = diolan_usb_cmd(dev, CMD_GET_SERIAL, true);
+ if (ret >= 4) {
+ serial = le32_to_cpu(*(u32 *)dev->ibuffer);
+ dev_info(&dev->interface->dev,
+ "Diolan U2C serial number %u\n", serial);
+ }
+}
+
+static int diolan_init(struct i2c_diolan_u2c *dev)
+{
+ int speed, ret;
+
+ if (frequency >= 200000) {
+ speed = U2C_I2C_SPEED_FAST;
+ frequency = U2C_I2C_FREQ_FAST;
+ } else if (frequency >= 100000 || frequency == 0) {
+ speed = U2C_I2C_SPEED_STD;
+ frequency = U2C_I2C_FREQ_STD;
+ } else {
+ speed = U2C_I2C_SPEED(frequency);
+ if (speed > U2C_I2C_SPEED_2KHZ)
+ speed = U2C_I2C_SPEED_2KHZ;
+ frequency = U2C_I2C_FREQ(speed);
+ }
+
+ dev_info(&dev->interface->dev,
+ "Diolan U2C at USB bus %03d address %03d speed %d Hz\n",
+ dev->usb_dev->bus->busnum, dev->usb_dev->devnum, frequency);
+
+ diolan_flush_input(dev);
+ diolan_fw_version(dev);
+ diolan_get_serial(dev);
+
+ /* Set I2C speed */
+ ret = diolan_set_speed(dev, speed);
+ if (ret < 0)
+ return ret;
+
+ /* Configure I2C clock synchronization */
+ ret = diolan_set_clock_synch(dev, speed != U2C_I2C_SPEED_FAST);
+ if (ret < 0)
+ return ret;
+
+ if (speed != U2C_I2C_SPEED_FAST)
+ ret = diolan_set_clock_synch_timeout(dev, DIOLAN_SYNC_TIMEOUT);
+
+ return ret;
+}
+
+/* i2c layer */
+
+static int diolan_usb_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
+ int num)
+{
+ struct i2c_diolan_u2c *dev = i2c_get_adapdata(adapter);
+ struct i2c_msg *pmsg;
+ int i, j;
+ int ret, sret;
+
+ ret = diolan_i2c_start(dev);
+ if (ret < 0)
+ return ret;
+
+ for (i = 0; i < num; i++) {
+ pmsg = &msgs[i];
+ if (i) {
+ ret = diolan_i2c_repeated_start(dev);
+ if (ret < 0)
+ goto abort;
+ }
+ if (pmsg->flags & I2C_M_RD) {
+ ret =
+ diolan_i2c_put_byte_ack(dev, (pmsg->addr << 1) | 1);
+ if (ret < 0)
+ goto abort;
+ for (j = 0; j < pmsg->len; j++) {
+ u8 byte;
+ bool ack = j < pmsg->len - 1;
+
+ /*
+ * Don't send NACK if this is the first byte
+ * of a SMBUS_BLOCK message.
+ */
+ if (j == 0 && (pmsg->flags & I2C_M_RECV_LEN))
+ ack = true;
+
+ ret = diolan_i2c_get_byte_ack(dev, ack, &byte);
+ if (ret < 0)
+ goto abort;
+ /*
+ * Adjust count if first received byte is length
+ */
+ if (j == 0 && (pmsg->flags & I2C_M_RECV_LEN)) {
+ if (byte == 0
+ || byte > I2C_SMBUS_BLOCK_MAX) {
+ ret = -EPROTO;
+ goto abort;
+ }
+ pmsg->len += byte;
+ }
+ pmsg->buf[j] = byte;
+ }
+ } else {
+ ret = diolan_i2c_put_byte_ack(dev, pmsg->addr << 1);
+ if (ret < 0)
+ goto abort;
+ for (j = 0; j < pmsg->len; j++) {
+ ret = diolan_i2c_put_byte_ack(dev,
+ pmsg->buf[j]);
+ if (ret < 0)
+ goto abort;
+ }
+ }
+ }
+abort:
+ sret = diolan_i2c_stop(dev);
+ if (sret < 0 && ret >= 0)
+ ret = sret;
+ return ret;
+}
+
+/*
+ * Return list of supported functionality.
+ */
+static u32 diolan_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 diolan_usb_algorithm = {
+ .master_xfer = diolan_usb_xfer,
+ .functionality = diolan_usb_func,
+};
+
+/* device layer */
+
+static const struct usb_device_id diolan_u2c_table[] = {
+ { USB_DEVICE(USB_VENDOR_ID_DIOLAN, USB_DEVICE_ID_DIOLAN_U2C) },
+ { }
+};
+
+MODULE_DEVICE_TABLE(usb, diolan_u2c_table);
+
+static void diolan_u2c_free(struct i2c_diolan_u2c *dev)
+{
+ usb_put_dev(dev->usb_dev);
+ kfree(dev);
+}
+
+static int diolan_u2c_probe(struct usb_interface *interface,
+ const struct usb_device_id *id)
+{
+ struct i2c_diolan_u2c *dev;
+ int ret;
+
+ /* 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;
+
+ /* save our data pointer in this interface device */
+ usb_set_intfdata(interface, dev);
+
+ /* setup i2c adapter description */
+ dev->adapter.owner = THIS_MODULE;
+ dev->adapter.class = I2C_CLASS_HWMON;
+ dev->adapter.algo = &diolan_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;
+
+ /* initialize diolan i2c interface */
+ ret = diolan_init(dev);
+ if (ret < 0) {
+ dev_err(&interface->dev, "failed to initialize adapter\n");
+ goto error_free;
+ }
+
+ /* 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_free;
+ }
+
+ dev_dbg(&interface->dev, "connected " DRIVER_NAME "\n");
+
+ return 0;
+
+error_free:
+ usb_set_intfdata(interface, NULL);
+ diolan_u2c_free(dev);
+error:
+ return ret;
+}
+
+static void diolan_u2c_disconnect(struct usb_interface *interface)
+{
+ struct i2c_diolan_u2c *dev = usb_get_intfdata(interface);
+
+ i2c_del_adapter(&dev->adapter);
+ usb_set_intfdata(interface, NULL);
+ diolan_u2c_free(dev);
+
+ dev_dbg(&interface->dev, "disconnected\n");
+}
+
+static struct usb_driver diolan_u2c_driver = {
+ .name = DRIVER_NAME,
+ .probe = diolan_u2c_probe,
+ .disconnect = diolan_u2c_disconnect,
+ .id_table = diolan_u2c_table,
+};
+
+static int __init diolan_u2c_init(void)
+{
+ /* register this driver with the USB subsystem */
+ return usb_register(&diolan_u2c_driver);
+}
+
+static void __exit diolan_u2c_exit(void)
+{
+ /* deregister this driver with the USB subsystem */
+ usb_deregister(&diolan_u2c_driver);
+}
+
+module_init(diolan_u2c_init);
+module_exit(diolan_u2c_exit);
+
+MODULE_AUTHOR("Guenter Roeck <guenter.roeck@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION(DRIVER_NAME " driver");
+MODULE_LICENSE("GPL");
--
1.7.3.1
--
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