1 files changed, 369 insertions, 0 deletions
diff --git a/drivers/nfc/fdp/i2c.c b/drivers/nfc/fdp/i2c.c
new file mode 100644
index 000000000..1e0f2297f
--- /dev/null
+++ b/drivers/nfc/fdp/i2c.c
@@ -0,0 +1,369 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* -------------------------------------------------------------------------
+ * Copyright (C) 2014-2016, Intel Corporation
+ *
+ * -------------------------------------------------------------------------
+ */
+
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/nfc.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <net/nfc/nfc.h>
+#include <net/nfc/nci_core.h>
+
+#include "fdp.h"
+
+#define FDP_I2C_DRIVER_NAME	"fdp_nci_i2c"
+
+#define FDP_DP_CLOCK_TYPE_NAME	"clock-type"
+#define FDP_DP_CLOCK_FREQ_NAME	"clock-freq"
+#define FDP_DP_FW_VSC_CFG_NAME	"fw-vsc-cfg"
+
+#define FDP_FRAME_HEADROOM	2
+#define FDP_FRAME_TAILROOM	1
+
+#define FDP_NCI_I2C_MIN_PAYLOAD	5
+#define FDP_NCI_I2C_MAX_PAYLOAD	261
+
+#define FDP_POWER_OFF		0
+#define FDP_POWER_ON		1
+
+#define fdp_nci_i2c_dump_skb(dev, prefix, skb)				\
+	print_hex_dump(KERN_DEBUG, prefix": ", DUMP_PREFIX_OFFSET,	\
+		       16, 1, (skb)->data, (skb)->len, 0)
+
+static void fdp_nci_i2c_reset(const struct fdp_i2c_phy *phy)
+{
+	/* Reset RST/WakeUP for at least 100 micro-second */
+	gpiod_set_value_cansleep(phy->power_gpio, FDP_POWER_OFF);
+	usleep_range(1000, 4000);
+	gpiod_set_value_cansleep(phy->power_gpio, FDP_POWER_ON);
+	usleep_range(10000, 14000);
+}
+
+static int fdp_nci_i2c_enable(void *phy_id)
+{
+	const struct fdp_i2c_phy *phy = phy_id;
+
+	fdp_nci_i2c_reset(phy);
+
+	return 0;
+}
+
+static void fdp_nci_i2c_disable(void *phy_id)
+{
+	const struct fdp_i2c_phy *phy = phy_id;
+
+	fdp_nci_i2c_reset(phy);
+}
+
+static void fdp_nci_i2c_add_len_lrc(struct sk_buff *skb)
+{
+	u8 lrc = 0;
+	u16 len, i;
+
+	/* Add length header */
+	len = skb->len;
+	*(u8 *)skb_push(skb, 1) = len & 0xff;
+	*(u8 *)skb_push(skb, 1) = len >> 8;
+
+	/* Compute and add lrc */
+	for (i = 0; i < len + 2; i++)
+		lrc ^= skb->data[i];
+
+	skb_put_u8(skb, lrc);
+}
+
+static void fdp_nci_i2c_remove_len_lrc(struct sk_buff *skb)
+{
+	skb_pull(skb, FDP_FRAME_HEADROOM);
+	skb_trim(skb, skb->len - FDP_FRAME_TAILROOM);
+}
+
+static int fdp_nci_i2c_write(void *phy_id, struct sk_buff *skb)
+{
+	struct fdp_i2c_phy *phy = phy_id;
+	struct i2c_client *client = phy->i2c_dev;
+	int r;
+
+	if (phy->hard_fault != 0)
+		return phy->hard_fault;
+
+	fdp_nci_i2c_add_len_lrc(skb);
+	fdp_nci_i2c_dump_skb(&client->dev, "fdp_wr", skb);
+
+	r = i2c_master_send(client, skb->data, skb->len);
+	if (r == -EREMOTEIO) {  /* Retry, chip was in standby */
+		usleep_range(1000, 4000);
+		r = i2c_master_send(client, skb->data, skb->len);
+	}
+
+	if (r < 0 || r != skb->len)
+		dev_dbg(&client->dev, "%s: error err=%d len=%d\n",
+			__func__, r, skb->len);
+
+	if (r >= 0) {
+		if (r != skb->len) {
+			phy->hard_fault = r;
+			r = -EREMOTEIO;
+		} else {
+			r = 0;
+		}
+	}
+
+	fdp_nci_i2c_remove_len_lrc(skb);
+
+	return r;
+}
+
+static const struct nfc_phy_ops i2c_phy_ops = {
+	.write = fdp_nci_i2c_write,
+	.enable = fdp_nci_i2c_enable,
+	.disable = fdp_nci_i2c_disable,
+};
+
+static int fdp_nci_i2c_read(struct fdp_i2c_phy *phy, struct sk_buff **skb)
+{
+	int r, len;
+	u8 tmp[FDP_NCI_I2C_MAX_PAYLOAD], lrc, k;
+	u16 i;
+	struct i2c_client *client = phy->i2c_dev;
+
+	*skb = NULL;
+
+	/* Read the length packet and the data packet */
+	for (k = 0; k < 2; k++) {
+
+		len = phy->next_read_size;
+
+		r = i2c_master_recv(client, tmp, len);
+		if (r != len) {
+			dev_dbg(&client->dev, "%s: i2c recv err: %d\n",
+				__func__, r);
+			goto flush;
+		}
+
+		/* Check packet integruty */
+		for (lrc = i = 0; i < r; i++)
+			lrc ^= tmp[i];
+
+		/*
+		 * LRC check failed. This may due to transmission error or
+		 * desynchronization between driver and FDP. Drop the packet
+		 * and force resynchronization
+		 */
+		if (lrc) {
+			dev_dbg(&client->dev, "%s: corrupted packet\n",
+				__func__);
+			phy->next_read_size = 5;
+			goto flush;
+		}
+
+		/* Packet that contains a length */
+		if (tmp[0] == 0 && tmp[1] == 0) {
+			phy->next_read_size = (tmp[2] << 8) + tmp[3] + 3;
+		} else {
+			phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD;
+
+			*skb = alloc_skb(len, GFP_KERNEL);
+			if (*skb == NULL) {
+				r = -ENOMEM;
+				goto flush;
+			}
+
+			skb_put_data(*skb, tmp, len);
+			fdp_nci_i2c_dump_skb(&client->dev, "fdp_rd", *skb);
+
+			fdp_nci_i2c_remove_len_lrc(*skb);
+		}
+	}
+
+	return 0;
+
+flush:
+	/* Flush the remaining data */
+	if (i2c_master_recv(client, tmp, sizeof(tmp)) < 0)
+		r = -EREMOTEIO;
+
+	return r;
+}
+
+static irqreturn_t fdp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
+{
+	struct fdp_i2c_phy *phy = phy_id;
+	struct sk_buff *skb;
+	int r;
+
+	if (!phy || irq != phy->i2c_dev->irq) {
+		WARN_ON_ONCE(1);
+		return IRQ_NONE;
+	}
+
+	r = fdp_nci_i2c_read(phy, &skb);
+
+	if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
+		return IRQ_HANDLED;
+
+	if (skb != NULL)
+		nci_recv_frame(phy->ndev, skb);
+
+	return IRQ_HANDLED;
+}
+
+static void fdp_nci_i2c_read_device_properties(struct device *dev,
+					       u8 *clock_type, u32 *clock_freq,
+					       u8 **fw_vsc_cfg)
+{
+	int r;
+	u8 len;
+
+	r = device_property_read_u8(dev, FDP_DP_CLOCK_TYPE_NAME, clock_type);
+	if (r) {
+		dev_dbg(dev, "Using default clock type");
+		*clock_type = 0;
+	}
+
+	r = device_property_read_u32(dev, FDP_DP_CLOCK_FREQ_NAME, clock_freq);
+	if (r) {
+		dev_dbg(dev, "Using default clock frequency\n");
+		*clock_freq = 26000;
+	}
+
+	if (device_property_present(dev, FDP_DP_FW_VSC_CFG_NAME)) {
+		r = device_property_read_u8(dev, FDP_DP_FW_VSC_CFG_NAME,
+					    &len);
+
+		if (r || len <= 0)
+			goto vsc_read_err;
+
+		/* Add 1 to the length to inclue the length byte itself */
+		len++;
+
+		*fw_vsc_cfg = devm_kmalloc_array(dev,
+					   len, sizeof(**fw_vsc_cfg),
+					   GFP_KERNEL);
+
+		if (!*fw_vsc_cfg)
+			goto alloc_err;
+
+		r = device_property_read_u8_array(dev, FDP_DP_FW_VSC_CFG_NAME,
+						  *fw_vsc_cfg, len);
+
+		if (r) {
+			devm_kfree(dev, *fw_vsc_cfg);
+			goto vsc_read_err;
+		}
+	} else {
+vsc_read_err:
+		dev_dbg(dev, "FW vendor specific commands not present\n");
+		*fw_vsc_cfg = NULL;
+	}
+
+alloc_err:
+	dev_dbg(dev, "Clock type: %d, clock frequency: %d, VSC: %s",
+		*clock_type, *clock_freq, *fw_vsc_cfg != NULL ? "yes" : "no");
+}
+
+static const struct acpi_gpio_params power_gpios = { 0, 0, false };
+
+static const struct acpi_gpio_mapping acpi_fdp_gpios[] = {
+	{ "power-gpios", &power_gpios, 1 },
+	{},
+};
+
+static int fdp_nci_i2c_probe(struct i2c_client *client)
+{
+	struct fdp_i2c_phy *phy;
+	struct device *dev = &client->dev;
+	u8 *fw_vsc_cfg;
+	u8 clock_type;
+	u32 clock_freq;
+	int r = 0;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		nfc_err(dev, "No I2C_FUNC_I2C support\n");
+		return -ENODEV;
+	}
+
+	/* Checking if we have an irq */
+	if (client->irq <= 0) {
+		nfc_err(dev, "IRQ not present\n");
+		return -ENODEV;
+	}
+
+	phy = devm_kzalloc(dev, sizeof(struct fdp_i2c_phy), GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	phy->i2c_dev = client;
+	phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD;
+	i2c_set_clientdata(client, phy);
+
+	r = devm_request_threaded_irq(dev, client->irq,
+				      NULL, fdp_nci_i2c_irq_thread_fn,
+				      IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+				      FDP_I2C_DRIVER_NAME, phy);
+
+	if (r < 0) {
+		nfc_err(&client->dev, "Unable to register IRQ handler\n");
+		return r;
+	}
+
+	r = devm_acpi_dev_add_driver_gpios(dev, acpi_fdp_gpios);
+	if (r)
+		dev_dbg(dev, "Unable to add GPIO mapping table\n");
+
+	/* Requesting the power gpio */
+	phy->power_gpio = devm_gpiod_get(dev, "power", GPIOD_OUT_LOW);
+	if (IS_ERR(phy->power_gpio)) {
+		nfc_err(dev, "Power GPIO request failed\n");
+		return PTR_ERR(phy->power_gpio);
+	}
+
+	/* read device properties to get the clock and production settings */
+	fdp_nci_i2c_read_device_properties(dev, &clock_type, &clock_freq,
+					   &fw_vsc_cfg);
+
+	/* Call the NFC specific probe function */
+	r = fdp_nci_probe(phy, &i2c_phy_ops, &phy->ndev,
+			  FDP_FRAME_HEADROOM, FDP_FRAME_TAILROOM,
+			  clock_type, clock_freq, fw_vsc_cfg);
+	if (r < 0) {
+		nfc_err(dev, "NCI probing error\n");
+		return r;
+	}
+
+	return 0;
+}
+
+static void fdp_nci_i2c_remove(struct i2c_client *client)
+{
+	struct fdp_i2c_phy *phy = i2c_get_clientdata(client);
+
+	fdp_nci_remove(phy->ndev);
+	fdp_nci_i2c_disable(phy);
+}
+
+static const struct acpi_device_id fdp_nci_i2c_acpi_match[] = {
+	{"INT339A", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, fdp_nci_i2c_acpi_match);
+
+static struct i2c_driver fdp_nci_i2c_driver = {
+	.driver = {
+		   .name = FDP_I2C_DRIVER_NAME,
+		   .acpi_match_table = fdp_nci_i2c_acpi_match,
+		  },
+	.probe_new = fdp_nci_i2c_probe,
+	.remove = fdp_nci_i2c_remove,
+};
+module_i2c_driver(fdp_nci_i2c_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("I2C driver for Intel Fields Peak NFC controller");
+MODULE_AUTHOR("Robert Dolca <robert.dolca@intel.com>");