NFC: st21nfcb: Add driver for STMicroelectronics ST21NFCB NFC chip (35630df6) · Commits · e / devices / android_kernel_teracube_emerald

drivers/nfc/Kconfig

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	@@ -72,5 +72,5 @@ source "drivers/nfc/pn544/Kconfig"
	source "drivers/nfc/microread/Kconfig"		source "drivers/nfc/microread/Kconfig"
	source "drivers/nfc/nfcmrvl/Kconfig"		source "drivers/nfc/nfcmrvl/Kconfig"
	source "drivers/nfc/st21nfca/Kconfig"		source "drivers/nfc/st21nfca/Kconfig"
			source "drivers/nfc/st21nfcb/Kconfig"
	endmenu		endmenu

drivers/nfc/Makefile

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	@@ -12,5 +12,6 @@ obj-$(CONFIG_NFC_PORT100) += port100.o
	obj-$(CONFIG_NFC_MRVL) += nfcmrvl/		obj-$(CONFIG_NFC_MRVL) += nfcmrvl/
	obj-$(CONFIG_NFC_TRF7970A) += trf7970a.o		obj-$(CONFIG_NFC_TRF7970A) += trf7970a.o
	obj-$(CONFIG_NFC_ST21NFCA) += st21nfca/		obj-$(CONFIG_NFC_ST21NFCA) += st21nfca/
			obj-$(CONFIG_NFC_ST21NFCB) += st21nfcb/

	ccflags-$(CONFIG_NFC_DEBUG) := -DDEBUG		ccflags-$(CONFIG_NFC_DEBUG) := -DDEBUG

drivers/nfc/st21nfcb/Kconfig

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			config NFC_ST21NFCB
			tristate "STMicroelectronics ST21NFCB NFC driver"
			depends on NFC_NCI
			default n
			---help---
			STMicroelectronics ST21NFCB core driver. It implements the chipset
			NCI logic and hooks into the NFC kernel APIs. Physical layers will
			register against it.

			To compile this driver as a module, choose m here. The module will
			be called st21nfcb.
			Say N if unsure.

			config NFC_ST21NFCB_I2C
			tristate "NFC ST21NFCB i2c support"
			depends on NFC_ST21NFCB && I2C
			---help---
			This module adds support for the STMicroelectronics st21nfcb i2c interface.
			Select this if your platform is using the i2c bus.

			If you choose to build a module, it'll be called st21nfcb_i2c.
			Say N if unsure.

drivers/nfc/st21nfcb/Makefile

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			#
			# Makefile for ST21NFCB NCI based NFC driver
			#

			st21nfcb_i2c-objs = i2c.o

			obj-$(CONFIG_NFC_ST21NFCB) += st21nfcb.o ndlc.o
			obj-$(CONFIG_NFC_ST21NFCB_I2C) += st21nfcb_i2c.o

drivers/nfc/st21nfcb/i2c.c

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			/*
			* I2C Link Layer for ST21NFCB NCI based Driver
			* Copyright (C) 2014 STMicroelectronics SAS. 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/crc-ccitt.h>
			#include <linux/module.h>
			#include <linux/i2c.h>
			#include <linux/gpio.h>
			#include <linux/of_irq.h>
			#include <linux/of_gpio.h>
			#include <linux/miscdevice.h>
			#include <linux/interrupt.h>
			#include <linux/delay.h>
			#include <linux/nfc.h>
			#include <linux/firmware.h>
			#include <linux/unaligned/access_ok.h>
			#include <linux/platform_data/st21nfcb.h>

			#include <net/nfc/nci.h>
			#include <net/nfc/llc.h>
			#include <net/nfc/nfc.h>

			#include "ndlc.h"

			#define DRIVER_DESC "NCI NFC driver for ST21NFCB"

			/* ndlc header */
			#define ST21NFCB_FRAME_HEADROOM 1
			#define ST21NFCB_FRAME_TAILROOM 0

			#define ST21NFCB_NCI_I2C_MIN_SIZE 4 /* PCB(1) + NCI Packet header(3) */
			#define ST21NFCB_NCI_I2C_MAX_SIZE 250 /* req 4.2.1 */

			#define ST21NFCB_NCI_I2C_DRIVER_NAME "st21nfcb_nci_i2c"

			static struct i2c_device_id st21nfcb_nci_i2c_id_table[] = {
			{ST21NFCB_NCI_DRIVER_NAME, 0},
			{}
			};
			MODULE_DEVICE_TABLE(i2c, st21nfcb_nci_i2c_id_table);

			struct st21nfcb_i2c_phy {
			struct i2c_client *i2c_dev;
			struct llt_ndlc *ndlc;

			unsigned int gpio_irq;
			unsigned int gpio_reset;
			unsigned int irq_polarity;

			int powered;

			/*
			* < 0 if hardware error occured (e.g. i2c err)
			* and prevents normal operation.
			*/
			int hard_fault;
			};

			#define I2C_DUMP_SKB(info, skb) \
			do { \
			pr_debug("%s:\n", info); \
			print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET, \
			16, 1, (skb)->data, (skb)->len, 0); \
			} while (0)

			static int st21nfcb_nci_i2c_enable(void *phy_id)
			{
			struct st21nfcb_i2c_phy *phy = phy_id;

			gpio_set_value(phy->gpio_reset, 0);
			usleep_range(10000, 15000);
			gpio_set_value(phy->gpio_reset, 1);
			phy->powered = 1;
			usleep_range(80000, 85000);

			return 0;
			}

			static void st21nfcb_nci_i2c_disable(void *phy_id)
			{
			struct st21nfcb_i2c_phy *phy = phy_id;

			pr_info("\n");

			phy->powered = 0;
			/* reset chip in order to flush clf */
			gpio_set_value(phy->gpio_reset, 0);
			usleep_range(10000, 15000);
			gpio_set_value(phy->gpio_reset, 1);
			}

			static void st21nfcb_nci_remove_header(struct sk_buff *skb)
			{
			skb_pull(skb, ST21NFCB_FRAME_HEADROOM);
			}

			/*
			* Writing a frame must not return the number of written bytes.
			* It must return either zero for success, or <0 for error.
			* In addition, it must not alter the skb
			*/
			static int st21nfcb_nci_i2c_write(void phy_id, struct sk_buff skb)
			{
			int r = -1;
			struct st21nfcb_i2c_phy *phy = phy_id;
			struct i2c_client *client = phy->i2c_dev;

			I2C_DUMP_SKB("st21nfcb_nci_i2c_write", skb);

			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(1000, 4000);
			r = i2c_master_send(client, skb->data, skb->len);
			}

			if (r >= 0) {
			if (r != skb->len)
			r = -EREMOTEIO;
			else
			r = 0;
			}

			st21nfcb_nci_remove_header(skb);

			return r;
			}

			/*
			* Reads an ndlc frame and returns it in a newly allocated sk_buff.
			* returns:
			* frame size : if received frame is complete (find ST21NFCB_SOF_EOF at
			* end of read)
			* -EAGAIN : if received frame is incomplete (not find ST21NFCB_SOF_EOF
			* at end of read)
			* -EREMOTEIO : i2c read error (fatal)
			* -EBADMSG : frame was incorrect and discarded
			* (value returned from st21nfcb_nci_i2c_repack)
			* -EIO : if no ST21NFCB_SOF_EOF is found after reaching
			* the read length end sequence
			*/
			static int st21nfcb_nci_i2c_read(struct st21nfcb_i2c_phy *phy,
			struct sk_buff **skb)
			{
			int r;
			u8 len;
			u8 buf[ST21NFCB_NCI_I2C_MAX_SIZE];
			struct i2c_client *client = phy->i2c_dev;

			r = i2c_master_recv(client, buf, 4);
			if (r == -EREMOTEIO) { /* Retry, chip was in standby */
			usleep_range(1000, 4000);
			r = i2c_master_recv(client, buf, 4);
			} else if (r != 4) {
			nfc_err(&client->dev, "cannot read ndlc & nci header\n");
			return -EREMOTEIO;
			}

			len = be16_to_cpu((__be16 ) (buf + 2));
			if (len > ST21NFCB_NCI_I2C_MAX_SIZE) {
			nfc_err(&client->dev, "invalid frame len\n");
			return -EBADMSG;
			}

			*skb = alloc_skb(4 + len, GFP_KERNEL);
			if (*skb == NULL)
			return -ENOMEM;

			skb_reserve(*skb, 4);
			skb_put(*skb, 4);
			memcpy((*skb)->data, buf, 4);

			if (!len)
			return 0;

			r = i2c_master_recv(client, buf, len);
			if (r != len) {
			kfree_skb(*skb);
			return -EREMOTEIO;
			}

			skb_put(*skb, len);
			memcpy((*skb)->data + 4, buf, len);

			I2C_DUMP_SKB("i2c frame read", *skb);

			return 0;
			}

			/*
			* Reads an ndlc frame from the chip.
			*
			* On ST21NFCB, IRQ goes in idle state when read starts.
			*/
			static irqreturn_t st21nfcb_nci_irq_thread_fn(int irq, void *phy_id)
			{
			struct st21nfcb_i2c_phy *phy = phy_id;
			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)
			return IRQ_HANDLED;

			if (!phy->powered) {
			st21nfcb_nci_i2c_disable(phy);
			return IRQ_HANDLED;
			}

			r = st21nfcb_nci_i2c_read(phy, &skb);
			if (r == -EREMOTEIO) {
			phy->hard_fault = r;
			ndlc_recv(phy->ndlc, NULL);
			return IRQ_HANDLED;
			} else if (r == -ENOMEM \|\| r == -EBADMSG) {
			return IRQ_HANDLED;
			}

			ndlc_recv(phy->ndlc, skb);

			return IRQ_HANDLED;
			}

			static struct nfc_phy_ops i2c_phy_ops = {
			.write = st21nfcb_nci_i2c_write,
			.enable = st21nfcb_nci_i2c_enable,
			.disable = st21nfcb_nci_i2c_disable,
			};

			#ifdef CONFIG_OF
			static int st21nfcb_nci_i2c_of_request_resources(struct i2c_client *client)
			{
			struct st21nfcb_i2c_phy *phy = i2c_get_clientdata(client);
			struct device_node *pp;
			int gpio;
			int r;

			pp = client->dev.of_node;
			if (!pp)
			return -ENODEV;

			/* Get GPIO from device tree */
			gpio = of_get_named_gpio(pp, "reset-gpios", 0);
			if (gpio < 0) {
			nfc_err(&client->dev,
			"Failed to retrieve reset-gpios from device tree\n");
			return gpio;
			}

			/* GPIO request and configuration */
			r = devm_gpio_request(&client->dev, gpio, "clf_reset");
			if (r) {
			nfc_err(&client->dev, "Failed to request reset pin\n");
			return -ENODEV;
			}

			r = gpio_direction_output(gpio, 1);
			if (r) {
			nfc_err(&client->dev,
			"Failed to set reset pin direction as output\n");
			return -ENODEV;
			}
			phy->gpio_reset = gpio;

			/* IRQ */
			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;
			}

			phy->irq_polarity = irq_get_trigger_type(r);
			client->irq = r;

			return 0;
			}
			#else
			static int st21nfcb_nci_i2c_of_request_resources(struct i2c_client *client)
			{
			return -ENODEV;
			}
			#endif

			static int st21nfcb_nci_i2c_request_resources(struct i2c_client *client)
			{
			struct st21nfcb_nfc_platform_data *pdata;
			struct st21nfcb_i2c_phy *phy = i2c_get_clientdata(client);
			int r;
			int irq;

			pdata = client->dev.platform_data;
			if (pdata == NULL) {
			nfc_err(&client->dev, "No platform data\n");
			return -EINVAL;
			}

			/* store for later use */
			phy->gpio_irq = pdata->gpio_irq;
			phy->gpio_reset = pdata->gpio_reset;
			phy->irq_polarity = pdata->irq_polarity;

			r = devm_gpio_request(&client->dev, phy->gpio_irq, "wake_up");
			if (r) {
			pr_err("%s : gpio_request failed\n", __FILE__);
			return -ENODEV;
			}

			r = gpio_direction_input(phy->gpio_irq);
			if (r) {
			pr_err("%s : gpio_direction_input failed\n", __FILE__);
			return -ENODEV;
			}

			r = devm_gpio_request(&client->dev,
			phy->gpio_reset, "clf_reset");
			if (r) {
			pr_err("%s : reset gpio_request failed\n", __FILE__);
			return -ENODEV;
			}

			r = gpio_direction_output(phy->gpio_reset, 1);
			if (r) {
			pr_err("%s : reset gpio_direction_output failed\n",
			__FILE__);
			return -ENODEV;
			}

			/* IRQ */
			irq = gpio_to_irq(phy->gpio_irq);
			if (irq < 0) {
			nfc_err(&client->dev,
			"Unable to get irq number for GPIO %d error %d\n",
			phy->gpio_irq, r);
			return -ENODEV;
			}
			client->irq = irq;

			return 0;
			}

			static int st21nfcb_nci_i2c_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
			{
			struct st21nfcb_i2c_phy *phy;
			struct st21nfcb_nfc_platform_data *pdata;
			int r;

			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 st21nfcb_i2c_phy),
			GFP_KERNEL);
			if (!phy) {
			nfc_err(&client->dev,
			"Cannot allocate memory for st21nfcb i2c phy.\n");
			return -ENOMEM;
			}

			phy->i2c_dev = client;

			i2c_set_clientdata(client, phy);

			pdata = client->dev.platform_data;
			if (!pdata && client->dev.of_node) {
			r = st21nfcb_nci_i2c_of_request_resources(client);
			if (r) {
			nfc_err(&client->dev, "No platform data\n");
			return r;
			}
			} else if (pdata) {
			r = st21nfcb_nci_i2c_request_resources(client);
			if (r) {
			nfc_err(&client->dev,
			"Cannot get platform resources\n");
			return r;
			}
			} else {
			nfc_err(&client->dev,
			"st21nfcb platform resources not available\n");
			return -ENODEV;
			}

			r = devm_request_threaded_irq(&client->dev, client->irq, NULL,
			st21nfcb_nci_irq_thread_fn,
			phy->irq_polarity \| IRQF_ONESHOT,
			ST21NFCB_NCI_DRIVER_NAME, phy);
			if (r < 0) {
			nfc_err(&client->dev, "Unable to register IRQ handler\n");
			return r;
			}

			return ndlc_probe(phy, &i2c_phy_ops, &client->dev,
			ST21NFCB_FRAME_HEADROOM, ST21NFCB_FRAME_TAILROOM,
			&phy->ndlc);
			}

			static int st21nfcb_nci_i2c_remove(struct i2c_client *client)
			{
			struct st21nfcb_i2c_phy *phy = i2c_get_clientdata(client);

			dev_dbg(&client->dev, "%s\n", __func__);

			ndlc_remove(phy->ndlc);

			if (phy->powered)
			st21nfcb_nci_i2c_disable(phy);

			return 0;
			}

			static const struct of_device_id of_st21nfcb_i2c_match[] = {
			{ .compatible = "st,st21nfcb_i2c", },
			{}
			};

			static struct i2c_driver st21nfcb_nci_i2c_driver = {
			.driver = {
			.owner = THIS_MODULE,
			.name = ST21NFCB_NCI_I2C_DRIVER_NAME,
			.owner = THIS_MODULE,
			.of_match_table = of_match_ptr(of_st21nfcb_i2c_match),
			},
			.probe = st21nfcb_nci_i2c_probe,
			.id_table = st21nfcb_nci_i2c_id_table,
			.remove = st21nfcb_nci_i2c_remove,
			};

			module_i2c_driver(st21nfcb_nci_i2c_driver);

			MODULE_LICENSE("GPL");
			MODULE_DESCRIPTION(DRIVER_DESC);