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Subject[RFC 4/4] NFC: pn533: add I2C phy driver
Date
This adds the I2C phy interface for the pn533 driver. This way the driver can
be used to interact with I2C connected pn532.

Signed-off-by: Michael Thalmeier <michael.thalmeier@hale.at>
---
drivers/nfc/pn533/Kconfig | 11 ++
drivers/nfc/pn533/Makefile | 2 +
drivers/nfc/pn533/i2c.c | 277 +++++++++++++++++++++++++++++++++++++++++++++
drivers/nfc/pn533/pn533.c | 29 +++++
drivers/nfc/pn533/pn533.h | 2 +
5 files changed, 321 insertions(+)
create mode 100644 drivers/nfc/pn533/i2c.c

diff --git a/drivers/nfc/pn533/Kconfig b/drivers/nfc/pn533/Kconfig
index b5a926e..d94122d 100644
--- a/drivers/nfc/pn533/Kconfig
+++ b/drivers/nfc/pn533/Kconfig
@@ -14,3 +14,14 @@ config NFC_PN533_USB

If you choose to build a module, it'll be called pn533_usb.
Say N if unsure.
+
+config NFC_PN533_I2C
+ tristate "NFC PN533 device support (I2C)"
+ depends on I2C
+ select NFC_PN533
+ ---help---
+ This module adds support for the NXP pn533 I2C interface.
+ Select this if your platform is using the I2C bus.
+
+ If you choose to build a module, it'll be called pn533_i2c.
+ Say N if unsure.
diff --git a/drivers/nfc/pn533/Makefile b/drivers/nfc/pn533/Makefile
index 12c6be4..51d24c6 100644
--- a/drivers/nfc/pn533/Makefile
+++ b/drivers/nfc/pn533/Makefile
@@ -2,6 +2,8 @@
# Makefile for PN533 NFC driver
#
pn533_usb-objs = usb.o
+pn533_i2c-objs = i2c.o

obj-$(CONFIG_NFC_PN533) += pn533.o
obj-$(CONFIG_NFC_PN533_USB) += pn533_usb.o
+obj-$(CONFIG_NFC_PN533_I2C) += pn533_i2c.o
diff --git a/drivers/nfc/pn533/i2c.c b/drivers/nfc/pn533/i2c.c
new file mode 100644
index 0000000..35066b30
--- /dev/null
+++ b/drivers/nfc/pn533/i2c.c
@@ -0,0 +1,277 @@
+/*
+ * 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
+ *
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#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;
+
+ int hard_fault; /*
+ * < 0 if hardware error occured (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;
+ 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;
+
+ 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)
+{
+ /* An ack will cancel the last issued command */
+ pn533_i2c_send_ack(dev, flags);
+
+ /* schedule cmd_complete_work to finish current command execution */
+ if (dev->cmd != NULL)
+ dev->cmd->status = -ENOENT;
+ queue_work(dev->wq, &dev->cmd_complete_work);
+}
+
+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;
+ }
+
+ pn533_recv_frame(phy->priv, skb, 0);
+
+ return IRQ_HANDLED;
+
+#if 0
+#endif
+}
+
+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) {
+ nfc_err(&client->dev,
+ "Cannot allocate memory for pn533 i2c phy.\n");
+ return -ENOMEM;
+ }
+
+ phy->i2c_dev = client;
+ i2c_set_clientdata(client, phy);
+
+ 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");
+ }
+
+ 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);
+
+ if (IS_ERR(priv)) {
+ r = PTR_ERR(priv);
+ goto err_register;
+ }
+
+ phy->priv = priv;
+
+ return 0;
+
+err_register:
+ free_irq(client->irq, phy);
+
+ 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__);
+
+ 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 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");
diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
index 4468284..3d286a7 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -2435,8 +2435,35 @@ static int pn533_rf_field(struct nfc_dev *nfc_dev, u8 rf)
return rc;
}

+static int pn532_sam_configuration(struct nfc_dev *nfc_dev)
+{
+ struct pn533 *dev = nfc_get_drvdata(nfc_dev);
+ struct sk_buff *skb;
+ struct sk_buff *resp;
+
+ skb = pn533_alloc_skb(dev, 1);
+ if (!skb)
+ return -ENOMEM;
+
+ *skb_put(skb, 1) = 0x01;
+
+ resp = pn533_send_cmd_sync(dev, PN533_CMD_SAM_CONFIGURATION, skb);
+ if (IS_ERR(resp))
+ return PTR_ERR(resp);
+
+ dev_kfree_skb(resp);
+ return 0;
+}
+
static int pn533_dev_up(struct nfc_dev *nfc_dev)
{
+ struct pn533 *dev = nfc_get_drvdata(nfc_dev);
+ if (dev->device_type == PN533_DEVICE_PN532) {
+ int rc = pn532_sam_configuration(nfc_dev);
+ if (rc)
+ return rc;
+ }
+
return pn533_rf_field(nfc_dev, 1);
}

@@ -2469,6 +2496,7 @@ static int pn533_setup(struct pn533 *dev)
case PN533_DEVICE_STD:
case PN533_DEVICE_PASORI:
case PN533_DEVICE_ACR122U:
+ case PN533_DEVICE_PN532:
max_retries.mx_rty_atr = 0x2;
max_retries.mx_rty_psl = 0x1;
max_retries.mx_rty_passive_act =
@@ -2504,6 +2532,7 @@ static int pn533_setup(struct pn533 *dev)

switch (dev->device_type) {
case PN533_DEVICE_STD:
+ case PN533_DEVICE_PN532:
break;

case PN533_DEVICE_PASORI:
diff --git a/drivers/nfc/pn533/pn533.h b/drivers/nfc/pn533/pn533.h
index 0958c653..61c5d6a 100644
--- a/drivers/nfc/pn533/pn533.h
+++ b/drivers/nfc/pn533/pn533.h
@@ -21,6 +21,7 @@
#define PN533_DEVICE_STD 0x1
#define PN533_DEVICE_PASORI 0x2
#define PN533_DEVICE_ACR122U 0x3
+#define PN533_DEVICE_PN532 0x4

#define PN533_ALL_PROTOCOLS (NFC_PROTO_JEWEL_MASK | NFC_PROTO_MIFARE_MASK |\
NFC_PROTO_FELICA_MASK | NFC_PROTO_ISO14443_MASK |\
@@ -72,6 +73,7 @@
#define PN533_FRAME_CMD(f) (f->data[1])

#define PN533_CMD_GET_FIRMWARE_VERSION 0x02
+#define PN533_CMD_SAM_CONFIGURATION 0x14
#define PN533_CMD_RF_CONFIGURATION 0x32
#define PN533_CMD_IN_DATA_EXCHANGE 0x40
#define PN533_CMD_IN_COMM_THRU 0x42
--
2.5.5
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