/* * 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 #include #include #include #include #include #include #define DLN2_I2C_MODULE_ID 0x03 #define DLN2_I2C_CMD(cmd) DLN2_CMD(cmd, DLN2_I2C_MODULE_ID) /* I2C commands */ #define DLN2_I2C_GET_PORT_COUNT DLN2_I2C_CMD(0x00) #define DLN2_I2C_ENABLE DLN2_I2C_CMD(0x01) #define DLN2_I2C_DISABLE DLN2_I2C_CMD(0x02) #define DLN2_I2C_IS_ENABLED DLN2_I2C_CMD(0x03) #define DLN2_I2C_WRITE DLN2_I2C_CMD(0x06) #define DLN2_I2C_READ DLN2_I2C_CMD(0x07) #define DLN2_I2C_SCAN_DEVICES DLN2_I2C_CMD(0x08) #define DLN2_I2C_PULLUP_ENABLE DLN2_I2C_CMD(0x09) #define DLN2_I2C_PULLUP_DISABLE DLN2_I2C_CMD(0x0A) #define DLN2_I2C_PULLUP_IS_ENABLED DLN2_I2C_CMD(0x0B) #define DLN2_I2C_TRANSFER DLN2_I2C_CMD(0x0C) #define DLN2_I2C_SET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0D) #define DLN2_I2C_GET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0E) #define DLN2_I2C_MAX_XFER_SIZE 256 #define DLN2_I2C_BUF_SIZE (DLN2_I2C_MAX_XFER_SIZE + 16) struct dln2_i2c { struct platform_device *pdev; struct i2c_adapter adapter; u8 port; /* * Buffer to hold the packet for read or write transfers. One is enough * since we can't have multiple transfers in parallel on the i2c bus. */ void *buf; }; static int dln2_i2c_enable(struct dln2_i2c *dln2, bool enable) { u16 cmd; struct { u8 port; } tx; tx.port = dln2->port; if (enable) cmd = DLN2_I2C_ENABLE; else cmd = DLN2_I2C_DISABLE; return dln2_transfer_tx(dln2->pdev, cmd, &tx, sizeof(tx)); } static int dln2_i2c_write(struct dln2_i2c *dln2, u8 addr, u8 *data, u16 data_len) { int ret; struct { u8 port; u8 addr; u8 mem_addr_len; __le32 mem_addr; __le16 buf_len; u8 buf[DLN2_I2C_MAX_XFER_SIZE]; } __packed *tx = dln2->buf; unsigned len; BUILD_BUG_ON(sizeof(*tx) > DLN2_I2C_BUF_SIZE); tx->port = dln2->port; 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_tx(dln2->pdev, DLN2_I2C_WRITE, tx, len); if (ret < 0) return ret; return data_len; } static int dln2_i2c_read(struct dln2_i2c *dln2, u16 addr, u8 *data, u16 data_len) { int ret; struct { u8 port; u8 addr; u8 mem_addr_len; __le32 mem_addr; __le16 buf_len; } __packed tx; struct { __le16 buf_len; u8 buf[DLN2_I2C_MAX_XFER_SIZE]; } __packed *rx = dln2->buf; unsigned rx_len = sizeof(*rx); BUILD_BUG_ON(sizeof(*rx) > DLN2_I2C_BUF_SIZE); tx.port = dln2->port; tx.addr = addr; tx.mem_addr_len = 0; tx.mem_addr = 0; tx.buf_len = cpu_to_le16(data_len); ret = dln2_transfer(dln2->pdev, DLN2_I2C_READ, &tx, sizeof(tx), rx, &rx_len); if (ret < 0) return ret; if (rx_len < sizeof(rx->buf_len) + data_len) return -EPROTO; if (le16_to_cpu(rx->buf_len) != data_len) return -EPROTO; memcpy(data, rx->buf, data_len); return data_len; } static int dln2_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) { struct dln2_i2c *dln2 = i2c_get_adapdata(adapter); struct i2c_msg *pmsg; struct device *dev = &dln2->adapter.dev; int i; for (i = 0; i < num; i++) { int ret; pmsg = &msgs[i]; if (pmsg->len > DLN2_I2C_MAX_XFER_SIZE) { dev_warn(dev, "maximum transfer size exceeded\n"); return -EOPNOTSUPP; } if (pmsg->flags & I2C_M_RD) { ret = dln2_i2c_read(dln2, pmsg->addr, pmsg->buf, pmsg->len); if (ret < 0) return ret; pmsg->len = ret; } else { ret = dln2_i2c_write(dln2, pmsg->addr, pmsg->buf, pmsg->len); if (ret != pmsg->len) return -EPROTO; } } return num; } 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 | I2C_FUNC_SMBUS_I2C_BLOCK; } static const struct i2c_algorithm dln2_i2c_usb_algorithm = { .master_xfer = dln2_i2c_xfer, .functionality = dln2_i2c_func, }; static int dln2_i2c_probe(struct platform_device *pdev) { int ret; struct dln2_i2c *dln2; struct device *dev = &pdev->dev; struct dln2_platform_data *pdata = dev_get_platdata(&pdev->dev); dln2 = devm_kzalloc(dev, sizeof(*dln2), GFP_KERNEL); if (!dln2) return -ENOMEM; dln2->buf = devm_kmalloc(dev, DLN2_I2C_BUF_SIZE, GFP_KERNEL); if (!dln2->buf) return -ENOMEM; dln2->pdev = pdev; dln2->port = pdata->port; /* setup i2c adapter description */ dln2->adapter.owner = THIS_MODULE; dln2->adapter.class = I2C_CLASS_HWMON; dln2->adapter.algo = &dln2_i2c_usb_algorithm; dln2->adapter.dev.parent = dev; i2c_set_adapdata(&dln2->adapter, dln2); snprintf(dln2->adapter.name, sizeof(dln2->adapter.name), "%s-%s-%d", "dln2-i2c", dev_name(pdev->dev.parent), dln2->port); platform_set_drvdata(pdev, dln2); /* initialize the i2c interface */ ret = dln2_i2c_enable(dln2, true); if (ret < 0) { dev_err(dev, "failed to initialize adapter: %d\n", ret); return ret; } /* and finally attach to i2c layer */ ret = i2c_add_adapter(&dln2->adapter); if (ret < 0) { dev_err(dev, "failed to add I2C adapter: %d\n", ret); goto out_disable; } return 0; out_disable: dln2_i2c_enable(dln2, false); return ret; } static int dln2_i2c_remove(struct platform_device *pdev) { struct dln2_i2c *dln2 = platform_get_drvdata(pdev); i2c_del_adapter(&dln2->adapter); dln2_i2c_enable(dln2, false); return 0; } static struct platform_driver dln2_i2c_driver = { .driver.name = "dln2-i2c", .probe = dln2_i2c_probe, .remove = dln2_i2c_remove, }; module_platform_driver(dln2_i2c_driver); MODULE_AUTHOR("Laurentiu Palcu "); MODULE_DESCRIPTION("Driver for the Diolan DLN2 I2C master interface"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:dln2-i2c");