i2c.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for NXP PN533 NFC Chip - I2C transport layer
*
* Copyright (C) 2011 Instituto Nokia de Tecnologia
* Copyright (C) 2012-2013 Tieto Poland
* Copyright (C) 2016 HALE electronic
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/nfc.h>
#include <linux/netdevice.h>
#include <linux/interrupt.h>
#include <net/nfc/nfc.h>
#include "pn533.h"
#define VERSION "0.1"
#define PN533_I2C_DRIVER_NAME "pn533_i2c"
struct pn533_i2c_phy {
struct i2c_client *i2c_dev;
struct pn533 *priv;
bool aborted;
int hard_fault; /*
* < 0 if hardware error occurred (e.g. i2c err)
* and prevents normal operation.
*/
};
static int pn533_i2c_send_ack(struct pn533 *dev, gfp_t flags)
{
struct pn533_i2c_phy *phy = dev->phy;
struct i2c_client *client = phy->i2c_dev;
static const u8 ack[6] = {0x00, 0x00, 0xff, 0x00, 0xff, 0x00};
/* spec 6.2.1.3: Preamble, SoPC (2), ACK Code (2), Postamble */
int rc;
rc = i2c_master_send(client, ack, 6);
return rc;
}
static int pn533_i2c_send_frame(struct pn533 *dev,
struct sk_buff *out)
{
struct pn533_i2c_phy *phy = dev->phy;
struct i2c_client *client = phy->i2c_dev;
int rc;
if (phy->hard_fault != 0)
return phy->hard_fault;
if (phy->priv == NULL)
phy->priv = dev;
phy->aborted = false;
print_hex_dump_debug("PN533_i2c TX: ", DUMP_PREFIX_NONE, 16, 1,
out->data, out->len, false);
rc = i2c_master_send(client, out->data, out->len);
if (rc == -EREMOTEIO) { /* Retry, chip was in power down */
usleep_range(6000, 10000);
rc = i2c_master_send(client, out->data, out->len);
}
if (rc >= 0) {
if (rc != out->len)
rc = -EREMOTEIO;
else
rc = 0;
}
return rc;
}
static void pn533_i2c_abort_cmd(struct pn533 *dev, gfp_t flags)
{
struct pn533_i2c_phy *phy = dev->phy;
phy->aborted = true;
/* An ack will cancel the last issued command */
pn533_i2c_send_ack(dev, flags);
/* schedule cmd_complete_work to finish current command execution */
pn533_recv_frame(phy->priv, NULL, -ENOENT);
}
static int pn533_i2c_read(struct pn533_i2c_phy *phy, struct sk_buff **skb)
{
struct i2c_client *client = phy->i2c_dev;
int len = PN533_EXT_FRAME_HEADER_LEN +
PN533_STD_FRAME_MAX_PAYLOAD_LEN +
PN533_STD_FRAME_TAIL_LEN + 1;
int r;
*skb = alloc_skb(len, GFP_KERNEL);
if (*skb == NULL)
return -ENOMEM;
r = i2c_master_recv(client, skb_put(*skb, len), len);
if (r != len) {
nfc_err(&client->dev, "cannot read. r=%d len=%d\n", r, len);
kfree_skb(*skb);
return -EREMOTEIO;
}
if (!((*skb)->data[0] & 0x01)) {
nfc_err(&client->dev, "READY flag not set");
kfree_skb(*skb);
return -EBUSY;
}
/* remove READY byte */
skb_pull(*skb, 1);
/* trim to frame size */
skb_trim(*skb, phy->priv->ops->rx_frame_size((*skb)->data));
return 0;
}
static irqreturn_t pn533_i2c_irq_thread_fn(int irq, void *data)
{
struct pn533_i2c_phy *phy = data;
struct i2c_client *client;
struct sk_buff *skb = NULL;
int r;
if (!phy || irq != phy->i2c_dev->irq) {
WARN_ON_ONCE(1);
return IRQ_NONE;
}
client = phy->i2c_dev;
dev_dbg(&client->dev, "IRQ\n");
if (phy->hard_fault != 0)
return IRQ_HANDLED;
r = pn533_i2c_read(phy, &skb);
if (r == -EREMOTEIO) {
phy->hard_fault = r;
pn533_recv_frame(phy->priv, NULL, -EREMOTEIO);
return IRQ_HANDLED;
} else if ((r == -ENOMEM) || (r == -EBADMSG) || (r == -EBUSY)) {
return IRQ_HANDLED;
}
if (!phy->aborted)
pn533_recv_frame(phy->priv, skb, 0);
return IRQ_HANDLED;
}
static struct pn533_phy_ops i2c_phy_ops = {
.send_frame = pn533_i2c_send_frame,
.send_ack = pn533_i2c_send_ack,
.abort_cmd = pn533_i2c_abort_cmd,
};
static int pn533_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pn533_i2c_phy *phy;
struct pn533 *priv;
int r = 0;
dev_dbg(&client->dev, "%s\n", __func__);
dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
return -ENODEV;
}
phy = devm_kzalloc(&client->dev, sizeof(struct pn533_i2c_phy),
GFP_KERNEL);
if (!phy)
return -ENOMEM;
phy->i2c_dev = client;
i2c_set_clientdata(client, phy);
priv = pn533_register_device(PN533_DEVICE_PN532,
PN533_NO_TYPE_B_PROTOCOLS,
PN533_PROTO_REQ_ACK_RESP,
phy, &i2c_phy_ops, NULL,
&phy->i2c_dev->dev,
&client->dev);
if (IS_ERR(priv)) {
r = PTR_ERR(priv);
return r;
}
phy->priv = priv;
r = request_threaded_irq(client->irq, NULL, pn533_i2c_irq_thread_fn,
IRQF_TRIGGER_FALLING |
IRQF_SHARED | IRQF_ONESHOT,
PN533_I2C_DRIVER_NAME, phy);
if (r < 0) {
nfc_err(&client->dev, "Unable to register IRQ handler\n");
goto irq_rqst_err;
}
r = pn533_finalize_setup(priv);
if (r)
goto fn_setup_err;
return 0;
fn_setup_err:
free_irq(client->irq, phy);
irq_rqst_err:
pn533_unregister_device(phy->priv);
return r;
}
static int pn533_i2c_remove(struct i2c_client *client)
{
struct pn533_i2c_phy *phy = i2c_get_clientdata(client);
dev_dbg(&client->dev, "%s\n", __func__);
free_irq(client->irq, phy);
pn533_unregister_device(phy->priv);
return 0;
}
static const struct of_device_id of_pn533_i2c_match[] = {
{ .compatible = "nxp,pn533-i2c", },
{ .compatible = "nxp,pn532-i2c", },
{},
};
MODULE_DEVICE_TABLE(of, of_pn533_i2c_match);
static const struct i2c_device_id pn533_i2c_id_table[] = {
{ PN533_I2C_DRIVER_NAME, 0 },
{}
};
MODULE_DEVICE_TABLE(i2c, pn533_i2c_id_table);
static struct i2c_driver pn533_i2c_driver = {
.driver = {
.name = PN533_I2C_DRIVER_NAME,
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(of_pn533_i2c_match),
},
.probe = pn533_i2c_probe,
.id_table = pn533_i2c_id_table,
.remove = pn533_i2c_remove,
};
module_i2c_driver(pn533_i2c_driver);
MODULE_AUTHOR("Michael Thalmeier <michael.thalmeier@hale.at>");
MODULE_DESCRIPTION("PN533 I2C driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");