1 files changed, 362 insertions, 0 deletions
diff --git a/drivers/nfc/nxp-nci/i2c.c b/drivers/nfc/nxp-nci/i2c.c
new file mode 100644
index 000000000..ec6446511
--- /dev/null
+++ b/drivers/nfc/nxp-nci/i2c.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * I2C link layer for the NXP NCI driver
+ *
+ * Copyright (C) 2014  NXP Semiconductors  All rights reserved.
+ * Copyright (C) 2012-2015  Intel Corporation. All rights reserved.
+ *
+ * Authors: Clément Perrochaud <clement.perrochaud@nxp.com>
+ * Authors: Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>
+ *
+ * Derived from PN544 device driver:
+ * Copyright (C) 2012  Intel Corporation. All rights reserved.
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/nfc.h>
+#include <linux/gpio/consumer.h>
+#include <asm/unaligned.h>
+
+#include <net/nfc/nfc.h>
+
+#include "nxp-nci.h"
+
+#define NXP_NCI_I2C_DRIVER_NAME	"nxp-nci_i2c"
+
+#define NXP_NCI_I2C_MAX_PAYLOAD	32
+
+struct nxp_nci_i2c_phy {
+	struct i2c_client *i2c_dev;
+	struct nci_dev *ndev;
+
+	struct gpio_desc *gpiod_en;
+	struct gpio_desc *gpiod_fw;
+
+	int hard_fault; /*
+			 * < 0 if hardware error occurred (e.g. i2c err)
+			 * and prevents normal operation.
+			 */
+};
+
+static int nxp_nci_i2c_set_mode(void *phy_id,
+				    enum nxp_nci_mode mode)
+{
+	struct nxp_nci_i2c_phy *phy = (struct nxp_nci_i2c_phy *) phy_id;
+
+	gpiod_set_value(phy->gpiod_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0);
+	gpiod_set_value(phy->gpiod_en, (mode != NXP_NCI_MODE_COLD) ? 1 : 0);
+	usleep_range(10000, 15000);
+
+	if (mode == NXP_NCI_MODE_COLD)
+		phy->hard_fault = 0;
+
+	return 0;
+}
+
+static int nxp_nci_i2c_write(void *phy_id, struct sk_buff *skb)
+{
+	int r;
+	struct nxp_nci_i2c_phy *phy = phy_id;
+	struct i2c_client *client = phy->i2c_dev;
+
+	if (phy->hard_fault != 0)
+		return phy->hard_fault;
+
+	r = i2c_master_send(client, skb->data, skb->len);
+	if (r < 0) {
+		/* Retry, chip was in standby */
+		msleep(110);
+		r = i2c_master_send(client, skb->data, skb->len);
+	}
+
+	if (r < 0) {
+		nfc_err(&client->dev, "Error %d on I2C send\n", r);
+	} else if (r != skb->len) {
+		nfc_err(&client->dev,
+			"Invalid length sent: %u (expected %u)\n",
+			r, skb->len);
+		r = -EREMOTEIO;
+	} else {
+		/* Success but return 0 and not number of bytes */
+		r = 0;
+	}
+
+	return r;
+}
+
+static const struct nxp_nci_phy_ops i2c_phy_ops = {
+	.set_mode = nxp_nci_i2c_set_mode,
+	.write = nxp_nci_i2c_write,
+};
+
+static int nxp_nci_i2c_fw_read(struct nxp_nci_i2c_phy *phy,
+			       struct sk_buff **skb)
+{
+	struct i2c_client *client = phy->i2c_dev;
+	u16 header;
+	size_t frame_len;
+	int r;
+
+	r = i2c_master_recv(client, (u8 *) &header, NXP_NCI_FW_HDR_LEN);
+	if (r < 0) {
+		goto fw_read_exit;
+	} else if (r != NXP_NCI_FW_HDR_LEN) {
+		nfc_err(&client->dev, "Incorrect header length: %u\n", r);
+		r = -EBADMSG;
+		goto fw_read_exit;
+	}
+
+	frame_len = (be16_to_cpu(header) & NXP_NCI_FW_FRAME_LEN_MASK) +
+		    NXP_NCI_FW_CRC_LEN;
+
+	*skb = alloc_skb(NXP_NCI_FW_HDR_LEN + frame_len, GFP_KERNEL);
+	if (*skb == NULL) {
+		r = -ENOMEM;
+		goto fw_read_exit;
+	}
+
+	skb_put_data(*skb, &header, NXP_NCI_FW_HDR_LEN);
+
+	r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len);
+	if (r < 0) {
+		goto fw_read_exit_free_skb;
+	} else if (r != frame_len) {
+		nfc_err(&client->dev,
+			"Invalid frame length: %u (expected %zu)\n",
+			r, frame_len);
+		r = -EBADMSG;
+		goto fw_read_exit_free_skb;
+	}
+
+	return 0;
+
+fw_read_exit_free_skb:
+	kfree_skb(*skb);
+fw_read_exit:
+	return r;
+}
+
+static int nxp_nci_i2c_nci_read(struct nxp_nci_i2c_phy *phy,
+				struct sk_buff **skb)
+{
+	struct nci_ctrl_hdr header; /* May actually be a data header */
+	struct i2c_client *client = phy->i2c_dev;
+	int r;
+
+	r = i2c_master_recv(client, (u8 *) &header, NCI_CTRL_HDR_SIZE);
+	if (r < 0) {
+		goto nci_read_exit;
+	} else if (r != NCI_CTRL_HDR_SIZE) {
+		nfc_err(&client->dev, "Incorrect header length: %u\n", r);
+		r = -EBADMSG;
+		goto nci_read_exit;
+	}
+
+	*skb = alloc_skb(NCI_CTRL_HDR_SIZE + header.plen, GFP_KERNEL);
+	if (*skb == NULL) {
+		r = -ENOMEM;
+		goto nci_read_exit;
+	}
+
+	skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE);
+
+	if (!header.plen)
+		return 0;
+
+	r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);
+	if (r < 0) {
+		goto nci_read_exit_free_skb;
+	} else if (r != header.plen) {
+		nfc_err(&client->dev,
+			"Invalid frame payload length: %u (expected %u)\n",
+			r, header.plen);
+		r = -EBADMSG;
+		goto nci_read_exit_free_skb;
+	}
+
+	return 0;
+
+nci_read_exit_free_skb:
+	kfree_skb(*skb);
+nci_read_exit:
+	return r;
+}
+
+static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
+{
+	struct nxp_nci_i2c_phy *phy = phy_id;
+	struct i2c_client *client;
+	struct nxp_nci_info *info;
+
+	struct sk_buff *skb = NULL;
+	int r = 0;
+
+	if (!phy || !phy->ndev)
+		goto exit_irq_none;
+
+	client = phy->i2c_dev;
+
+	if (!client || irq != client->irq)
+		goto exit_irq_none;
+
+	info = nci_get_drvdata(phy->ndev);
+
+	if (!info)
+		goto exit_irq_none;
+
+	mutex_lock(&info->info_lock);
+
+	if (phy->hard_fault != 0)
+		goto exit_irq_handled;
+
+	switch (info->mode) {
+	case NXP_NCI_MODE_NCI:
+		r = nxp_nci_i2c_nci_read(phy, &skb);
+		break;
+	case NXP_NCI_MODE_FW:
+		r = nxp_nci_i2c_fw_read(phy, &skb);
+		break;
+	case NXP_NCI_MODE_COLD:
+		r = -EREMOTEIO;
+		break;
+	}
+
+	if (r == -EREMOTEIO) {
+		phy->hard_fault = r;
+		if (info->mode == NXP_NCI_MODE_FW)
+			nxp_nci_fw_recv_frame(phy->ndev, NULL);
+	}
+	if (r < 0) {
+		nfc_err(&client->dev, "Read failed with error %d\n", r);
+		goto exit_irq_handled;
+	}
+
+	switch (info->mode) {
+	case NXP_NCI_MODE_NCI:
+		nci_recv_frame(phy->ndev, skb);
+		break;
+	case NXP_NCI_MODE_FW:
+		nxp_nci_fw_recv_frame(phy->ndev, skb);
+		break;
+	case NXP_NCI_MODE_COLD:
+		break;
+	}
+
+exit_irq_handled:
+	mutex_unlock(&info->info_lock);
+	return IRQ_HANDLED;
+exit_irq_none:
+	WARN_ON_ONCE(1);
+	return IRQ_NONE;
+}
+
+static const struct acpi_gpio_params firmware_gpios = { 1, 0, false };
+static const struct acpi_gpio_params enable_gpios = { 2, 0, false };
+
+static const struct acpi_gpio_mapping acpi_nxp_nci_gpios[] = {
+	{ "enable-gpios", &enable_gpios, 1 },
+	{ "firmware-gpios", &firmware_gpios, 1 },
+	{ }
+};
+
+static int nxp_nci_i2c_probe(struct i2c_client *client,
+			    const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct nxp_nci_i2c_phy *phy;
+	int r;
+
+	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 nxp_nci_i2c_phy),
+			   GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	phy->i2c_dev = client;
+	i2c_set_clientdata(client, phy);
+
+	r = devm_acpi_dev_add_driver_gpios(dev, acpi_nxp_nci_gpios);
+	if (r)
+		dev_dbg(dev, "Unable to add GPIO mapping table\n");
+
+	phy->gpiod_en = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(phy->gpiod_en)) {
+		nfc_err(dev, "Failed to get EN gpio\n");
+		return PTR_ERR(phy->gpiod_en);
+	}
+
+	phy->gpiod_fw = devm_gpiod_get_optional(dev, "firmware", GPIOD_OUT_LOW);
+	if (IS_ERR(phy->gpiod_fw)) {
+		nfc_err(dev, "Failed to get FW gpio\n");
+		return PTR_ERR(phy->gpiod_fw);
+	}
+
+	r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
+			  NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
+	if (r < 0)
+		return r;
+
+	r = request_threaded_irq(client->irq, NULL,
+				 nxp_nci_i2c_irq_thread_fn,
+				 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+				 NXP_NCI_I2C_DRIVER_NAME, phy);
+	if (r < 0)
+		nfc_err(&client->dev, "Unable to register IRQ handler\n");
+
+	return r;
+}
+
+static void nxp_nci_i2c_remove(struct i2c_client *client)
+{
+	struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);
+
+	nxp_nci_remove(phy->ndev);
+	free_irq(client->irq, phy);
+}
+
+static const struct i2c_device_id nxp_nci_i2c_id_table[] = {
+	{"nxp-nci_i2c", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, nxp_nci_i2c_id_table);
+
+static const struct of_device_id of_nxp_nci_i2c_match[] = {
+	{ .compatible = "nxp,nxp-nci-i2c", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_nxp_nci_i2c_match);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id acpi_id[] = {
+	{ "NXP1001" },
+	{ "NXP7471" },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, acpi_id);
+#endif
+
+static struct i2c_driver nxp_nci_i2c_driver = {
+	.driver = {
+		   .name = NXP_NCI_I2C_DRIVER_NAME,
+		   .acpi_match_table = ACPI_PTR(acpi_id),
+		   .of_match_table = of_nxp_nci_i2c_match,
+		  },
+	.probe = nxp_nci_i2c_probe,
+	.id_table = nxp_nci_i2c_id_table,
+	.remove = nxp_nci_i2c_remove,
+};
+
+module_i2c_driver(nxp_nci_i2c_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("I2C driver for NXP NCI NFC controllers");
+MODULE_AUTHOR("Clément Perrochaud <clement.perrochaud@nxp.com>");
+MODULE_AUTHOR("Oleg Zhurakivskyy <oleg.zhurakivskyy@intel.com>");