drivers/nfc/fdp/i2c.c - linux - Git at Google

 // 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);

 		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;
 	}

 	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>");
	// 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);

	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;
	}

	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>");