diff options
Diffstat (limited to 'drivers/nfc/pn533/i2c.c')
| -rw-r--r-- | drivers/nfc/pn533/i2c.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/drivers/nfc/pn533/i2c.c b/drivers/nfc/pn533/i2c.c new file mode 100644 index 000000000000..1dc89248e58e --- /dev/null +++ b/drivers/nfc/pn533/i2c.c @@ -0,0 +1,281 @@ +/* + * 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; + + 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; + 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); + + 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, + &client->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); + + free_irq(client->irq, phy); + + 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"); |
