Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6be88670 authored by Clément Perrochaud's avatar Clément Perrochaud Committed by Samuel Ortiz
Browse files

NFC: nxp-nci_i2c: Add I2C support to NXP NCI driver 



Add a module to the NXP-NCI driver to support NFC controllers with an
I2C control interface, such as the NPC100.

Signed-off-by: default avatarClément Perrochaud <clement.perrochaud@effinnov.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent dece4585

Documentation/devicetree/bindings/net/nfc/nxp-nci.txt

0 → 100644
+35 −0
Original line number Diff line number Diff line 
* NXP Semiconductors NXP NCI NFC Controllers



Required properties:

- compatible: Should be "nxp,nxp-nci-i2c".

- clock-frequency: I²C work frequency.

- reg: address on the bus

- interrupt-parent: phandle for the interrupt gpio controller

- interrupts: GPIO interrupt to which the chip is connected

- enable-gpios: Output GPIO pin used for enabling/disabling the chip

- firmware-gpios: Output GPIO pin used to enter firmware download mode



Optional SoC Specific Properties:

- pinctrl-names: Contains only one value - "default".

- pintctrl-0: Specifies the pin control groups used for this controller.



Example (for ARM-based BeagleBone with NPC100 NFC controller on I2C2):



&i2c2 {



	status = "okay";



	npc100: npc100@29 {



		compatible = "nxp,nxp-nci-i2c";



		reg = <0x29>;

		clock-frequency = <100000>;



		interrupt-parent = <&gpio1>;

		interrupts = <29 GPIO_ACTIVE_HIGH>;



		enable-gpios = <&gpio0 30 GPIO_ACTIVE_HIGH>;

		firmware-gpios = <&gpio0 31 GPIO_ACTIVE_HIGH>;

	};

};

drivers/nfc/nxp-nci/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -11,3 +11,15 @@ config NFC_NXP_NCI 
	  To compile this driver as a module, choose m here. The module will

	  be called nxp_nci.

	  Say N if unsure.



config NFC_NXP_NCI_I2C

	tristate "NXP-NCI I2C support"

	depends on NFC_NXP_NCI && I2C

	---help---

	  This module adds support for an I2C interface to the NXP NCI

	  chips.

	  Select this if your platform is using the I2C bus.



	  To compile this driver as a module, choose m here. The module will

	  be called nxp_nci_i2c.

	  Say Y if unsure.

drivers/nfc/nxp-nci/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -3,7 +3,9 @@ 
#



nxp-nci-objs = core.o firmware.o

nxp-nci_i2c-objs = i2c.o



obj-$(CONFIG_NFC_NXP_NCI) += nxp-nci.o

obj-$(CONFIG_NFC_NXP_NCI_I2C) += nxp-nci_i2c.o



ccflags-$(CONFIG_NFC_DEBUG) := -DDEBUG

drivers/nfc/nxp-nci/i2c.c

0 → 100644
+415 −0
Original line number Diff line number Diff line 
/*

 * I2C link layer for the NXP NCI driver

 *

 * Copyright (C) 2014  NXP Semiconductors  All rights reserved.

 *

 * Authors: Clément Perrochaud <clement.perrochaud@nxp.com>

 *

 * Derived from PN544 device driver:

 * Copyright (C) 2012  Intel Corporation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * 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/>.

 */



#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt



#include <linux/delay.h>

#include <linux/i2c.h>

#include <linux/interrupt.h>

#include <linux/miscdevice.h>

#include <linux/module.h>

#include <linux/nfc.h>

#include <linux/of_gpio.h>

#include <linux/of_irq.h>

#include <linux/platform_data/nxp-nci.h>

#include <linux/unaligned/access_ok.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;



	unsigned int gpio_en;

	unsigned int gpio_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;



	gpio_set_value(phy->gpio_fw, (mode == NXP_NCI_MODE_FW) ? 1 : 0);

	gpio_set_value(phy->gpio_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 == -EREMOTEIO) {

		/* Retry, chip was in standby */

		usleep_range(110000, 120000);

		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 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 = (get_unaligned_be16(&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;

	}



	memcpy(skb_put(*skb, NXP_NCI_FW_HDR_LEN), &header, NXP_NCI_FW_HDR_LEN);



	r = i2c_master_recv(client, skb_put(*skb, frame_len), frame_len);

	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;

	}



	memcpy(skb_put(*skb, NCI_CTRL_HDR_SIZE), (void *) &header,

	       NCI_CTRL_HDR_SIZE);



	r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen);

	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;

		skb = NULL;

	} else 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;

}



#ifdef CONFIG_OF



static int nxp_nci_i2c_parse_devtree(struct i2c_client *client)

{

	struct nxp_nci_i2c_phy *phy = i2c_get_clientdata(client);

	struct device_node *pp;

	int r;



	pp = client->dev.of_node;

	if (!pp)

		return -ENODEV;



	r = of_get_named_gpio(pp, "enable-gpios", 0);

	if (r == -EPROBE_DEFER)

		r = of_get_named_gpio(pp, "enable-gpios", 0);

	if (r < 0) {

		nfc_err(&client->dev, "Failed to get EN gpio, error: %d\n", r);

		return r;

	}

	phy->gpio_en = r;



	r = of_get_named_gpio(pp, "firmware-gpios", 0);

	if (r == -EPROBE_DEFER)

		r = of_get_named_gpio(pp, "firmware-gpios", 0);

	if (r < 0) {

		nfc_err(&client->dev, "Failed to get FW gpio, error: %d\n", r);

		return r;

	}

	phy->gpio_fw = r;



	r = irq_of_parse_and_map(pp, 0);

	if (r < 0) {

		nfc_err(&client->dev, "Unable to get irq, error: %d\n", r);

		return r;

	}

	client->irq = r;



	return 0;

}



#else



static int nxp_nci_i2c_parse_devtree(struct i2c_client *client)

{

	return -ENODEV;

}



#endif



static int nxp_nci_i2c_probe(struct i2c_client *client,

			    const struct i2c_device_id *id)

{

	struct nxp_nci_i2c_phy *phy;

	struct nxp_nci_nfc_platform_data *pdata;

	int r;



	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {

		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");

		r = -ENODEV;

		goto probe_exit;

	}



	phy = devm_kzalloc(&client->dev, sizeof(struct nxp_nci_i2c_phy),

			   GFP_KERNEL);

	if (!phy) {

		r = -ENOMEM;

		goto probe_exit;

	}



	phy->i2c_dev = client;

	i2c_set_clientdata(client, phy);



	pdata = client->dev.platform_data;



	if (!pdata && client->dev.of_node) {

		r = nxp_nci_i2c_parse_devtree(client);

		if (r < 0) {

			nfc_err(&client->dev, "Failed to get DT data\n");

			goto probe_exit;

		}

	} else if (pdata) {

		phy->gpio_en = pdata->gpio_en;

		phy->gpio_fw = pdata->gpio_fw;

		client->irq = pdata->irq;

	} else {

		nfc_err(&client->dev, "No platform data\n");

		r = -EINVAL;

		goto probe_exit;

	}



	r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,

				  GPIOF_OUT_INIT_LOW, "nxp_nci_en");

	if (r < 0)

		goto probe_exit;



	r = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw,

				  GPIOF_OUT_INIT_LOW, "nxp_nci_fw");

	if (r < 0)

		goto probe_exit;



	r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,

			  NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);

	if (r < 0)

		goto probe_exit;



	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");



probe_exit:

	return r;

}



static int 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);



	return 0;

}



static 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);



static struct i2c_driver nxp_nci_i2c_driver = {

	.driver = {

		   .name = NXP_NCI_I2C_DRIVER_NAME,

		   .owner  = THIS_MODULE,

		   .of_match_table = of_match_ptr(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>");