i2c: add support for Diolan DLN-2 USB-I2C adapter (db23e500) · Commits · 戴 / test

drivers/i2c/busses/Kconfig

+10 −0

Original line number	Diff line number	Diff line
		@@ -881,6 +881,16 @@ config I2C_DIOLAN_U2C
		This driver can also be built as a module. If so, the module
		will be called i2c-diolan-u2c.

		config I2C_DLN2
		tristate "Diolan DLN-2 USB I2C adapter"
		depends on MFD_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.

		config I2C_PARPORT
		tristate "Parallel port adapter"
		depends on PARPORT

drivers/i2c/busses/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -87,6 +87,7 @@ obj-$(CONFIG_I2C_RCAR) += i2c-rcar.o

		# External I2C/SMBus adapter drivers
		obj-$(CONFIG_I2C_DIOLAN_U2C) += i2c-diolan-u2c.o
		obj-$(CONFIG_I2C_DLN2) += i2c-dln2.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

drivers/i2c/busses/i2c-dln2.c

0 → 100644

+267 −0

Original line number	Diff line number	Diff line
		/*
		* 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/module.h>
		#include <linux/types.h>
		#include <linux/slab.h>
		#include <linux/i2c.h>
		#include <linux/platform_device.h>
		#include <linux/mfd/dln2.h>

		#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)
		{
		int ret;
		u16 cmd;
		struct {
		u8 port;
		} tx;

		tx.port = dln2->port;

		if (enable)
		cmd = DLN2_I2C_ENABLE;
		else
		cmd = DLN2_I2C_DISABLE;

		ret = dln2_transfer_tx(dln2->pdev, cmd, &tx, sizeof(tx));
		if (ret < 0)
		return ret;

		return 0;
		}

		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 <laurentiu.palcu@intel.com>");
		MODULE_DESCRIPTION("Driver for the Diolan DLN2 I2C master interface");
		MODULE_LICENSE("GPL v2");
		MODULE_ALIAS("platform:dln2-i2c");

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