Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Nano River Technologies viperboard i2c master driver
 *
 *  (C) 2012 by Lemonage GmbH
 *  Author: Lars Poeschel <poeschel@lemonage.de>
 *  All rights reserved.
 */
 
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
 
#include <linux/usb.h>
#include <linux/i2c.h>
 
#include <linux/mfd/viperboard.h>
 
struct vprbrd_i2c {
<------>struct i2c_adapter i2c;
<------>u8 bus_freq_param;
};
 
/* i2c bus frequency module parameter */
static u8 i2c_bus_param;
static unsigned int i2c_bus_freq = 100;
module_param(i2c_bus_freq, int, 0);
MODULE_PARM_DESC(i2c_bus_freq,
<------>"i2c bus frequency in khz (default is 100) valid values: 10, 100, 200, 400, 1000, 3000, 6000");
 
static int vprbrd_i2c_status(struct i2c_adapter *i2c,
<------>struct vprbrd_i2c_status *status, bool prev_error)
{
<------>u16 bytes_xfer;
<------>int ret;
<------>struct vprbrd *vb = (struct vprbrd *)i2c->algo_data;
 
<------>/* check for protocol error */
<------>bytes_xfer = sizeof(struct vprbrd_i2c_status);
 
<------>ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
<------><------>VPRBRD_USB_REQUEST_I2C, VPRBRD_USB_TYPE_IN, 0x0000, 0x0000,
<------><------>status, bytes_xfer, VPRBRD_USB_TIMEOUT_MS);
 
<------>if (ret != bytes_xfer)
<------><------>prev_error = true;
 
<------>if (prev_error) {
<------><------>dev_err(&i2c->dev, "failure in usb communication\n");
<------><------>return -EREMOTEIO;
<------>}
 
<------>dev_dbg(&i2c->dev, "  status = %d\n", status->status);
<------>if (status->status != 0x00) {
<------><------>dev_err(&i2c->dev, "failure: i2c protocol error\n");
<------><------>return -EPROTO;
<------>}
<------>return 0;
}
 
static int vprbrd_i2c_receive(struct usb_device *usb_dev,
<------>struct vprbrd_i2c_read_msg *rmsg, int bytes_xfer)
{
<------>int ret, bytes_actual;
<------>int error = 0;
 
<------>/* send the read request */
<------>ret = usb_bulk_msg(usb_dev,
<------><------>usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), rmsg,
<------><------>sizeof(struct vprbrd_i2c_read_hdr), &bytes_actual,
<------><------>VPRBRD_USB_TIMEOUT_MS);
 
<------>if ((ret < 0)
<------><------>|| (bytes_actual != sizeof(struct vprbrd_i2c_read_hdr))) {
<------><------>dev_err(&usb_dev->dev, "failure transmitting usb\n");
<------><------>error = -EREMOTEIO;
<------>}
 
<------>/* read the actual data */
<------>ret = usb_bulk_msg(usb_dev,
<------><------>usb_rcvbulkpipe(usb_dev, VPRBRD_EP_IN), rmsg,
<------><------>bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
 
<------>if ((ret < 0) || (bytes_xfer != bytes_actual)) {
<------><------>dev_err(&usb_dev->dev, "failure receiving usb\n");
<------><------>error = -EREMOTEIO;
<------>}
<------>return error;
}
 
static int vprbrd_i2c_addr(struct usb_device *usb_dev,
<------>struct vprbrd_i2c_addr_msg *amsg)
{
<------>int ret, bytes_actual;
 
<------>ret = usb_bulk_msg(usb_dev,
<------><------>usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), amsg,
<------><------>sizeof(struct vprbrd_i2c_addr_msg), &bytes_actual,
<------><------>VPRBRD_USB_TIMEOUT_MS);
 
<------>if ((ret < 0) ||
<------><------><------>(sizeof(struct vprbrd_i2c_addr_msg) != bytes_actual)) {
<------><------>dev_err(&usb_dev->dev, "failure transmitting usb\n");
<------><------>return -EREMOTEIO;
<------>}
<------>return 0;
}
 
static int vprbrd_i2c_read(struct vprbrd *vb, struct i2c_msg *msg)
{
<------>int ret;
<------>u16 remain_len, len1, len2, start = 0x0000;
<------>struct vprbrd_i2c_read_msg *rmsg =
<------><------>(struct vprbrd_i2c_read_msg *)vb->buf;
 
<------>remain_len = msg->len;
<------>rmsg->header.cmd = VPRBRD_I2C_CMD_READ;
<------>while (remain_len > 0) {
<------><------>rmsg->header.addr = cpu_to_le16(start + 0x4000);
<------><------>if (remain_len <= 255) {
<------><------><------>len1 = remain_len;
<------><------><------>len2 = 0x00;
<------><------><------>rmsg->header.len0 = remain_len;
<------><------><------>rmsg->header.len1 = 0x00;
<------><------><------>rmsg->header.len2 = 0x00;
<------><------><------>rmsg->header.len3 = 0x00;
<------><------><------>rmsg->header.len4 = 0x00;
<------><------><------>rmsg->header.len5 = 0x00;
<------><------><------>remain_len = 0;
<------><------>} else if (remain_len <= 510) {
<------><------><------>len1 = remain_len;
<------><------><------>len2 = 0x00;
<------><------><------>rmsg->header.len0 = remain_len - 255;
<------><------><------>rmsg->header.len1 = 0xff;
<------><------><------>rmsg->header.len2 = 0x00;
<------><------><------>rmsg->header.len3 = 0x00;
<------><------><------>rmsg->header.len4 = 0x00;
<------><------><------>rmsg->header.len5 = 0x00;
<------><------><------>remain_len = 0;
<------><------>} else if (remain_len <= 512) {
<------><------><------>len1 = remain_len;
<------><------><------>len2 = 0x00;
<------><------><------>rmsg->header.len0 = remain_len - 510;
<------><------><------>rmsg->header.len1 = 0xff;
<------><------><------>rmsg->header.len2 = 0xff;
<------><------><------>rmsg->header.len3 = 0x00;
<------><------><------>rmsg->header.len4 = 0x00;
<------><------><------>rmsg->header.len5 = 0x00;
<------><------><------>remain_len = 0;
<------><------>} else if (remain_len <= 767) {
<------><------><------>len1 = 512;
<------><------><------>len2 = remain_len - 512;
<------><------><------>rmsg->header.len0 = 0x02;
<------><------><------>rmsg->header.len1 = 0xff;
<------><------><------>rmsg->header.len2 = 0xff;
<------><------><------>rmsg->header.len3 = remain_len - 512;
<------><------><------>rmsg->header.len4 = 0x00;
<------><------><------>rmsg->header.len5 = 0x00;
<------><------><------>remain_len = 0;
<------><------>} else if (remain_len <= 1022) {
<------><------><------>len1 = 512;
<------><------><------>len2 = remain_len - 512;
<------><------><------>rmsg->header.len0 = 0x02;
<------><------><------>rmsg->header.len1 = 0xff;
<------><------><------>rmsg->header.len2 = 0xff;
<------><------><------>rmsg->header.len3 = remain_len - 767;
<------><------><------>rmsg->header.len4 = 0xff;
<------><------><------>rmsg->header.len5 = 0x00;
<------><------><------>remain_len = 0;
<------><------>} else if (remain_len <= 1024) {
<------><------><------>len1 = 512;
<------><------><------>len2 = remain_len - 512;
<------><------><------>rmsg->header.len0 = 0x02;
<------><------><------>rmsg->header.len1 = 0xff;
<------><------><------>rmsg->header.len2 = 0xff;
<------><------><------>rmsg->header.len3 = remain_len - 1022;
<------><------><------>rmsg->header.len4 = 0xff;
<------><------><------>rmsg->header.len5 = 0xff;
<------><------><------>remain_len = 0;
<------><------>} else {
<------><------><------>len1 = 512;
<------><------><------>len2 = 512;
<------><------><------>rmsg->header.len0 = 0x02;
<------><------><------>rmsg->header.len1 = 0xff;
<------><------><------>rmsg->header.len2 = 0xff;
<------><------><------>rmsg->header.len3 = 0x02;
<------><------><------>rmsg->header.len4 = 0xff;
<------><------><------>rmsg->header.len5 = 0xff;
<------><------><------>remain_len -= 1024;
<------><------><------>start += 1024;
<------><------>}
<------><------>rmsg->header.tf1 = cpu_to_le16(len1);
<------><------>rmsg->header.tf2 = cpu_to_le16(len2);
 
<------><------>/* first read transfer */
<------><------>ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len1);
<------><------>if (ret < 0)
<------><------><------>return ret;
<------><------>/* copy the received data */
<------><------>memcpy(msg->buf + start, rmsg, len1);
 
<------><------>/* second read transfer if neccessary */
<------><------>if (len2 > 0) {
<------><------><------>ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len2);
<------><------><------>if (ret < 0)
<------><------><------><------>return ret;
<------><------><------>/* copy the received data */
<------><------><------>memcpy(msg->buf + start + 512, rmsg, len2);
<------><------>}
<------>}
<------>return 0;
}
 
static int vprbrd_i2c_write(struct vprbrd *vb, struct i2c_msg *msg)
{
<------>int ret, bytes_actual;
<------>u16 remain_len, bytes_xfer,
<------><------>start = 0x0000;
<------>struct vprbrd_i2c_write_msg *wmsg =
<------><------>(struct vprbrd_i2c_write_msg *)vb->buf;
 
<------>remain_len = msg->len;
<------>wmsg->header.cmd = VPRBRD_I2C_CMD_WRITE;
<------>wmsg->header.last = 0x00;
<------>wmsg->header.chan = 0x00;
<------>wmsg->header.spi = 0x0000;
<------>while (remain_len > 0) {
<------><------>wmsg->header.addr = cpu_to_le16(start + 0x4000);
<------><------>if (remain_len > 503) {
<------><------><------>wmsg->header.len1 = 0xff;
<------><------><------>wmsg->header.len2 = 0xf8;
<------><------><------>remain_len -= 503;
<------><------><------>bytes_xfer = 503 + sizeof(struct vprbrd_i2c_write_hdr);
<------><------><------>start += 503;
<------><------>} else if (remain_len > 255) {
<------><------><------>wmsg->header.len1 = 0xff;
<------><------><------>wmsg->header.len2 = (remain_len - 255);
<------><------><------>bytes_xfer = remain_len +
<------><------><------><------>sizeof(struct vprbrd_i2c_write_hdr);
<------><------><------>remain_len = 0;
<------><------>} else {
<------><------><------>wmsg->header.len1 = remain_len;
<------><------><------>wmsg->header.len2 = 0x00;
<------><------><------>bytes_xfer = remain_len +
<------><------><------><------>sizeof(struct vprbrd_i2c_write_hdr);
<------><------><------>remain_len = 0;
<------><------>}
<------><------>memcpy(wmsg->data, msg->buf + start,
<------><------><------>bytes_xfer - sizeof(struct vprbrd_i2c_write_hdr));
 
<------><------>ret = usb_bulk_msg(vb->usb_dev,
<------><------><------>usb_sndbulkpipe(vb->usb_dev,
<------><------><------>VPRBRD_EP_OUT), wmsg,
<------><------><------>bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
<------><------>if ((ret < 0) || (bytes_xfer != bytes_actual))
<------><------><------>return -EREMOTEIO;
<------>}
<------>return 0;
}
 
static int vprbrd_i2c_xfer(struct i2c_adapter *i2c, struct i2c_msg *msgs,
<------><------>int num)
{
<------>struct i2c_msg *pmsg;
<------>int i, ret,
<------><------>error = 0;
<------>struct vprbrd *vb = (struct vprbrd *)i2c->algo_data;
<------>struct vprbrd_i2c_addr_msg *amsg =
<------><------>(struct vprbrd_i2c_addr_msg *)vb->buf;
<------>struct vprbrd_i2c_status *smsg = (struct vprbrd_i2c_status *)vb->buf;
 
<------>dev_dbg(&i2c->dev, "master xfer %d messages:\n", num);
 
<------>for (i = 0 ; i < num ; i++) {
<------><------>pmsg = &msgs[i];
 
<------><------>dev_dbg(&i2c->dev,
<------><------><------>"  %d: %s (flags %d) %d bytes to 0x%02x\n",
<------><------><------>i, pmsg->flags & I2C_M_RD ? "read" : "write",
<------><------><------>pmsg->flags, pmsg->len, pmsg->addr);
 
<------><------>mutex_lock(&vb->lock);
<------><------>/* directly send the message */
<------><------>if (pmsg->flags & I2C_M_RD) {
<------><------><------>/* read data */
<------><------><------>amsg->cmd = VPRBRD_I2C_CMD_ADDR;
<------><------><------>amsg->unknown2 = 0x00;
<------><------><------>amsg->unknown3 = 0x00;
<------><------><------>amsg->addr = pmsg->addr;
<------><------><------>amsg->unknown1 = 0x01;
<------><------><------>amsg->len = cpu_to_le16(pmsg->len);
<------><------><------>/* send the addr and len, we're interested to board */
<------><------><------>ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
<------><------><------>if (ret < 0)
<------><------><------><------>error = ret;
 
<------><------><------>ret = vprbrd_i2c_read(vb, pmsg);
<------><------><------>if (ret < 0)
<------><------><------><------>error = ret;
 
<------><------><------>ret = vprbrd_i2c_status(i2c, smsg, error);
<------><------><------>if (ret < 0)
<------><------><------><------>error = ret;
<------><------><------>/* in case of protocol error, return the error */
<------><------><------>if (error < 0)
<------><------><------><------>goto error;
<------><------>} else {
<------><------><------>/* write data */
<------><------><------>ret = vprbrd_i2c_write(vb, pmsg);
 
<------><------><------>amsg->cmd = VPRBRD_I2C_CMD_ADDR;
<------><------><------>amsg->unknown2 = 0x00;
<------><------><------>amsg->unknown3 = 0x00;
<------><------><------>amsg->addr = pmsg->addr;
<------><------><------>amsg->unknown1 = 0x00;
<------><------><------>amsg->len = cpu_to_le16(pmsg->len);
<------><------><------>/* send the addr, the data goes to to board */
<------><------><------>ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
<------><------><------>if (ret < 0)
<------><------><------><------>error = ret;
 
<------><------><------>ret = vprbrd_i2c_status(i2c, smsg, error);
<------><------><------>if (ret < 0)
<------><------><------><------>error = ret;
 
<------><------><------>if (error < 0)
<------><------><------><------>goto error;
<------><------>}
<------><------>mutex_unlock(&vb->lock);
<------>}
<------>return num;
error:
<------>mutex_unlock(&vb->lock);
<------>return error;
}
 
static u32 vprbrd_i2c_func(struct i2c_adapter *i2c)
{
<------>return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
 
/* This is the actual algorithm we define */
static const struct i2c_algorithm vprbrd_algorithm = {
<------>.master_xfer	= vprbrd_i2c_xfer,
<------>.functionality	= vprbrd_i2c_func,
};
 
static const struct i2c_adapter_quirks vprbrd_quirks = {
<------>.max_read_len = 2048,
<------>.max_write_len = 2048,
};
 
static int vprbrd_i2c_probe(struct platform_device *pdev)
{
<------>struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
<------>struct vprbrd_i2c *vb_i2c;
<------>int ret;
<------>int pipe;
 
<------>vb_i2c = devm_kzalloc(&pdev->dev, sizeof(*vb_i2c), GFP_KERNEL);
<------>if (vb_i2c == NULL)
<------><------>return -ENOMEM;
 
<------>/* setup i2c adapter description */
<------>vb_i2c->i2c.owner = THIS_MODULE;
<------>vb_i2c->i2c.class = I2C_CLASS_HWMON;
<------>vb_i2c->i2c.algo = &vprbrd_algorithm;
<------>vb_i2c->i2c.quirks = &vprbrd_quirks;
<------>vb_i2c->i2c.algo_data = vb;
<------>/* save the param in usb capabable memory */
<------>vb_i2c->bus_freq_param = i2c_bus_param;
 
<------>snprintf(vb_i2c->i2c.name, sizeof(vb_i2c->i2c.name),
<------><------> "viperboard at bus %03d device %03d",
<------><------> vb->usb_dev->bus->busnum, vb->usb_dev->devnum);
 
<------>/* setting the bus frequency */
<------>if ((i2c_bus_param <= VPRBRD_I2C_FREQ_10KHZ)
<------><------>&& (i2c_bus_param >= VPRBRD_I2C_FREQ_6MHZ)) {
<------><------>pipe = usb_sndctrlpipe(vb->usb_dev, 0);
<------><------>ret = usb_control_msg(vb->usb_dev, pipe,
<------><------><------>VPRBRD_USB_REQUEST_I2C_FREQ, VPRBRD_USB_TYPE_OUT,
<------><------><------>0x0000, 0x0000, &vb_i2c->bus_freq_param, 1,
<------><------><------>VPRBRD_USB_TIMEOUT_MS);
<------><------>if (ret != 1) {
<------><------><------>dev_err(&pdev->dev, "failure setting i2c_bus_freq to %d\n",
<------><------><------><------>i2c_bus_freq);
<------><------><------>return -EIO;
<------><------>}
<------>} else {
<------><------>dev_err(&pdev->dev,
<------><------><------>"invalid i2c_bus_freq setting:%d\n", i2c_bus_freq);
<------><------>return -EIO;
<------>}
 
<------>vb_i2c->i2c.dev.parent = &pdev->dev;
 
<------>/* attach to i2c layer */
<------>i2c_add_adapter(&vb_i2c->i2c);
 
<------>platform_set_drvdata(pdev, vb_i2c);
 
<------>return 0;
}
 
static int vprbrd_i2c_remove(struct platform_device *pdev)
{
<------>struct vprbrd_i2c *vb_i2c = platform_get_drvdata(pdev);
 
<------>i2c_del_adapter(&vb_i2c->i2c);
 
<------>return 0;
}
 
static struct platform_driver vprbrd_i2c_driver = {
<------>.driver.name	= "viperboard-i2c",
<------>.driver.owner	= THIS_MODULE,
<------>.probe		= vprbrd_i2c_probe,
<------>.remove		= vprbrd_i2c_remove,
};
 
static int __init vprbrd_i2c_init(void)
{
<------>switch (i2c_bus_freq) {
<------>case 6000:
<------><------>i2c_bus_param = VPRBRD_I2C_FREQ_6MHZ;
<------><------>break;
<------>case 3000:
<------><------>i2c_bus_param = VPRBRD_I2C_FREQ_3MHZ;
<------><------>break;
<------>case 1000:
<------><------>i2c_bus_param = VPRBRD_I2C_FREQ_1MHZ;
<------><------>break;
<------>case 400:
<------><------>i2c_bus_param = VPRBRD_I2C_FREQ_400KHZ;
<------><------>break;
<------>case 200:
<------><------>i2c_bus_param = VPRBRD_I2C_FREQ_200KHZ;
<------><------>break;
<------>case 100:
<------><------>i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
<------><------>break;
<------>case 10:
<------><------>i2c_bus_param = VPRBRD_I2C_FREQ_10KHZ;
<------><------>break;
<------>default:
<------><------>pr_warn("invalid i2c_bus_freq (%d)\n", i2c_bus_freq);
<------><------>i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
<------>}
 
<------>return platform_driver_register(&vprbrd_i2c_driver);
}
subsys_initcall(vprbrd_i2c_init);
 
static void __exit vprbrd_i2c_exit(void)
{
<------>platform_driver_unregister(&vprbrd_i2c_driver);
}
module_exit(vprbrd_i2c_exit);
 
MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
MODULE_DESCRIPTION("I2C master driver for Nano River Techs Viperboard");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:viperboard-i2c");