From: Laurentiu Palcu <laurentiu.palcu@xxxxxxxxx> This patch adds support for the Diolan DLN-2 I2C master module. Due to hardware limitations it does not support SMBUS quick commands. Information about the USB protocol interface can be found in the Programmer's Reference Manual [1], see section 6.2.2 for the I2C master module commands and responses. [1] https://www.diolan.com/downloads/dln-api-manual.pdf Signed-off-by: Laurentiu Palcu <laurentiu.palcu@xxxxxxxxx> --- drivers/i2c/busses/Kconfig | 11 ++ drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-dln2.c | 328 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 340 insertions(+) create mode 100644 drivers/i2c/busses/i2c-dln2.c diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 2ac87fa..06b1e89 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -1021,4 +1021,15 @@ config SCx200_ACB This support is also available as a module. If so, the module will be called scx200_acb. +config I2C_DLN2 + tristate "Diolan DLN-2 USB I2C adapter" + depends on USB + select USB_DLN2 + help + If you say yes to this option, support will be included for Diolan + DLN2, a USB to I2C interface. + + This driver can also be built as a module. If so, the module + will be called i2c-dln2. + endmenu diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 49bf07e..3118fea 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -100,5 +100,6 @@ obj-$(CONFIG_I2C_ELEKTOR) += i2c-elektor.o obj-$(CONFIG_I2C_PCA_ISA) += i2c-pca-isa.o obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o obj-$(CONFIG_SCx200_ACB) += scx200_acb.o +obj-$(CONFIG_I2C_DLN2) += i2c-dln2.o ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG diff --git a/drivers/i2c/busses/i2c-dln2.c b/drivers/i2c/busses/i2c-dln2.c new file mode 100644 index 0000000..7befbb0 --- /dev/null +++ b/drivers/i2c/busses/i2c-dln2.c @@ -0,0 +1,328 @@ +/* + * Driver for the Diolan DLN-2 USB-I2C adapter + * + * Copyright (c) 2014 Intel Corporation + * + * 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/dln2.h> +#include <linux/i2c.h> + +#define DRIVER_NAME "i2c-dln2" + +#define DLN2_I2C_MODULE_ID 0x03 +#define DLN2_I2C_CMD(cmd) DLN2_CMD(cmd, DLN2_I2C_MODULE_ID) + +/* I2C commands */ +#define CMD_I2C_GET_PORT_COUNT DLN2_I2C_CMD(0x00) +#define CMD_I2C_ENABLE DLN2_I2C_CMD(0x01) +#define CMD_I2C_DISABLE DLN2_I2C_CMD(0x02) +#define CMD_I2C_IS_ENABLED DLN2_I2C_CMD(0x03) +#define CMD_I2C_SET_FREQUENCY DLN2_I2C_CMD(0x04) +#define CMD_I2C_GET_FREQUENCY DLN2_I2C_CMD(0x05) +#define CMD_I2C_WRITE DLN2_I2C_CMD(0x06) +#define CMD_I2C_READ DLN2_I2C_CMD(0x07) +#define CMD_I2C_SCAN_DEVICES DLN2_I2C_CMD(0x08) +#define CMD_I2C_PULLUP_ENABLE DLN2_I2C_CMD(0x09) +#define CMD_I2C_PULLUP_DISABLE DLN2_I2C_CMD(0x0A) +#define CMD_I2C_PULLUP_IS_ENABLED DLN2_I2C_CMD(0x0B) +#define CMD_I2C_TRANSFER DLN2_I2C_CMD(0x0C) +#define CMD_I2C_SET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0D) +#define CMD_I2C_GET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0E) +#define CMD_I2C_GET_MIN_FREQUENCY DLN2_I2C_CMD(0x40) +#define CMD_I2C_GET_MAX_FREQUENCY DLN2_I2C_CMD(0x41) + +#define DLN2_I2C_FREQ_FAST 400000 +#define DLN2_I2C_FREQ_STD 100000 + +#define DLN2_I2C_MAX_XFER_SIZE 256 + +static struct dln2_mod *dln2_i2c_mod; + +/* Structure to hold all of our device specific stuff */ +struct dln2_i2c { + struct i2c_adapter adapter; /* i2c related things */ + struct dln2_dev *dln2; +}; + +static uint frequency = DLN2_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"); + +static int dln2_i2c_set_state(struct dln2_i2c *dev, u8 state) +{ + int ret; + u8 port = 0; + + ret = dln2_transfer(dev->dln2, dln2_i2c_mod, + state ? CMD_I2C_ENABLE : CMD_I2C_DISABLE, + &port, sizeof(port), NULL, NULL); + + if (ret < 0) + return ret; + + return 0; +} + +#define dln2_i2c_enable(dev) dln2_i2c_set_state(dev, 1) +#define dln2_i2c_disable(dev) dln2_i2c_set_state(dev, 0) + +static int dln2_i2c_set_frequency(struct dln2_i2c *dev, u32 freq) +{ + int ret; + struct tx_data { + u8 port; + __le32 freq; + } __packed tx; + + tx.port = 0; + tx.freq = cpu_to_le32(freq); + + ret = dln2_transfer(dev->dln2, dln2_i2c_mod, CMD_I2C_SET_FREQUENCY, + &tx, sizeof(tx), NULL, NULL); + if (ret < 0) + return ret; + + return 0; +} + +static int dln2_i2c_write(struct dln2_i2c *dev, u8 addr, + u8 *data, u16 data_len) +{ + int ret, len; + struct tx_data { + u8 port; + u8 addr; + u8 mem_addr_len; + __le32 mem_addr; + __le16 buf_len; + u8 buf[DLN2_I2C_MAX_XFER_SIZE]; + } __packed tx; + + if (data_len > DLN2_I2C_MAX_XFER_SIZE) + return -ENOSPC; + + tx.port = 0; + tx.addr = addr; + tx.mem_addr_len = 0; + tx.mem_addr = 0; + tx.buf_len = cpu_to_le16(data_len); + memcpy(tx.buf, data, data_len); + + len = sizeof(tx) + data_len - DLN2_I2C_MAX_XFER_SIZE; + ret = dln2_transfer(dev->dln2, dln2_i2c_mod, CMD_I2C_WRITE, + &tx, len, NULL, NULL); + if (ret < 0) + return ret; + + return data_len; +} + +static int dln2_i2c_read(struct dln2_i2c *dev, u16 addr, u8 *data, + u16 data_len) +{ + struct tx_data { + u8 port; + u8 addr; + u8 mem_addr_len; + __le32 mem_addr; + __le16 buf_len; + } __packed tx; + struct rx_data { + __le16 buf_len; + u8 buf[DLN2_I2C_MAX_XFER_SIZE]; + } __packed rx; + int ret, rx_len = sizeof(rx), buf_len; + + + tx.port = 0; + tx.addr = addr; + tx.mem_addr_len = 0; + tx.mem_addr = 0; + tx.buf_len = cpu_to_le16(data_len); + + ret = dln2_transfer(dev->dln2, dln2_i2c_mod, CMD_I2C_READ, &tx, + sizeof(tx), &rx, &rx_len); + if (ret < 0) + return ret; + + buf_len = le16_to_cpu(rx.buf_len); + + if (rx_len < buf_len) { + dev_warn(&dev->adapter.dev, "RX len mismatch: %d %d\n", + rx_len, buf_len); + buf_len = rx_len; + } + + dev_dbg(&dev->adapter.dev, "Rcvd: %d bytes", buf_len); + + memcpy(data, rx.buf, min(rx_len, buf_len)); + + return rx_len; +} + +static int dln2_i2c_setup(struct dln2_i2c *dev) +{ + int ret; + + ret = dln2_i2c_disable(dev); + if (ret < 0) + return ret; + + /* Set I2C frequency */ + ret = dln2_i2c_set_frequency(dev, frequency); + if (ret < 0) + return ret; + + ret = dln2_i2c_enable(dev); + + return ret; +} + +static int dln2_i2c_xfer(struct i2c_adapter *adapter, + struct i2c_msg *msgs, int num) +{ + struct dln2_i2c *dev = i2c_get_adapdata(adapter); + struct i2c_msg *pmsg; + int i; + int ret = 0; + + for (i = 0; i < num; i++) { + pmsg = &msgs[i]; + + if (pmsg->len > DLN2_I2C_MAX_XFER_SIZE) + return -EINVAL; + + if (pmsg->flags & I2C_M_RD) { + ret = dln2_i2c_read(dev, pmsg->addr, pmsg->buf, + pmsg->len); + if (ret < 0) + return ret; + + pmsg->len = ret; + } else { + ret = dln2_i2c_write(dev, pmsg->addr, pmsg->buf, + pmsg->len); + if (ret != pmsg->len) + return -EPROTO; + } + } + + return num; +} + +/* + * Return list of supported functionality. + */ +static u32 dln2_i2c_func(struct i2c_adapter *a) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL; +} + +static const struct i2c_algorithm dln2_i2c_usb_algorithm = { + .master_xfer = dln2_i2c_xfer, + .functionality = dln2_i2c_func, +}; + +/* device layer */ + +static int dln2_i2c_connect(struct dln2_dev *dln2) +{ + int ret; + struct dln2_i2c *dev = kzalloc(sizeof(*dev), GFP_KERNEL); + + if (!dev) + return -ENOMEM; + + /* setup i2c adapter description */ + dev->adapter.owner = THIS_MODULE; + dev->adapter.class = I2C_CLASS_HWMON; + dev->adapter.algo = &dln2_i2c_usb_algorithm; + i2c_set_adapdata(&dev->adapter, dev); + snprintf(dev->adapter.name, sizeof(dev->adapter.name), DRIVER_NAME); + + dev->adapter.dev.parent = dln2_get_device(dln2); + + dev->dln2 = dln2; + dln2_set_dev_context(dln2, dln2_i2c_mod, dev); + + /* initialize the i2c interface */ + ret = dln2_i2c_setup(dev); + if (ret < 0) { + dev_err(&dev->adapter.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(&dev->adapter.dev, "failed to add I2C adapter\n"); + goto error_free; + } + + dev_dbg(&dev->adapter.dev, "connected " DRIVER_NAME "\n"); + + return 0; + +error_free: + kfree(dev); + + return ret; +} + +static void dln2_i2c_disconnect(struct dln2_dev *dln2) +{ + struct dln2_i2c *dev = dln2_get_dev_context(dln2, dln2_i2c_mod); + + i2c_del_adapter(&dev->adapter); + + dev_dbg(&dev->adapter.dev, "disconnected" DRIVER_NAME "\n"); +} + +static struct dln2_mod_ops dln2_i2c_ops = { + .name = DRIVER_NAME, + .connect = dln2_i2c_connect, + .disconnect = dln2_i2c_disconnect, +}; + +static int __init dln2_i2c_init(void) +{ + int err; + + dln2_i2c_mod = dln2_register_module(-1, &dln2_i2c_ops); + + if (IS_ERR(dln2_i2c_mod)) { + err = PTR_ERR(dln2_i2c_mod); + dln2_i2c_mod = NULL; + pr_err(DRIVER_NAME "dln2_register_module failed: %d\n", err); + return err; + } + + return 0; +} +module_init(dln2_i2c_init); + +static void __exit dln2_i2c_exit(void) +{ + if (dln2_i2c_mod) + dln2_unregister_module(dln2_i2c_mod); +} +module_exit(dln2_i2c_exit); + +MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@xxxxxxxxx>"); +MODULE_DESCRIPTION(DRIVER_NAME " driver"); +MODULE_LICENSE("GPL"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
