linux/drivers/i2c/busses/i2c-dln2.c
Octavian Purdila 3b10db23c0 i2c: dln2: set the device tree node of the adapter
This patch makes sure the platform device tree node is inherited by
the adapter device. This allows the DLN2 bus to work with i2c devices
defined in the device tree.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-27 16:56:21 +01:00

264 lines
6.1 KiB
C

/*
* 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)
{
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;
int i;
for (i = 0; i < num; i++) {
int ret;
pmsg = &msgs[i];
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 struct i2c_adapter_quirks dln2_i2c_quirks = {
.max_read_len = DLN2_I2C_MAX_XFER_SIZE,
.max_write_len = DLN2_I2C_MAX_XFER_SIZE,
};
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.quirks = &dln2_i2c_quirks;
dln2->adapter.dev.parent = dev;
dln2->adapter.dev.of_node = dev->of_node;
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");