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Commit 59ee2361 authored by Thierry Escande's avatar Thierry Escande Committed by Samuel Ortiz
Browse files

NFC Digital: Implement driver commands mechanism 



This implements the mechanism used to send commands to the driver in
initiator mode through in_send_cmd().

Commands are serialized and sent to the driver by using a work item
on the system workqueue. Responses are handled asynchronously by
another work item. Once the digital stack receives the response through
the command_complete callback, the next command is sent to the driver.

This also implements the polling mechanism. It's handled by a work item
cycling on all supported protocols. The start poll command for a given
protocol is sent to the driver using the mechanism described above.
The process continues until a peer is discovered or stop_poll is
called. This patch implements the poll function for NFC-A that sends a
SENS_REQ command and waits for the SENS_RES response.

Signed-off-by: default avatarThierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent 4b10884e

include/net/nfc/digital.h

+25 −0
Original line number Diff line number Diff line
@@ -146,6 +146,15 @@ struct nfc_digital_ops { 
	void (*abort_cmd)(struct nfc_digital_dev *ddev);

};



#define NFC_DIGITAL_POLL_MODE_COUNT_MAX	6 /* 106A, 212F, and 424F in & tg */



typedef int (*digital_poll_t)(struct nfc_digital_dev *ddev, u8 rf_tech);



struct digital_poll_tech {

	u8 rf_tech;

	digital_poll_t poll_func;

};



/**

 * Driver capabilities - bit mask made of the following values

 *
@@ -168,6 +177,22 @@ struct nfc_digital_dev { 


	u32 driver_capabilities;

	void *driver_data;



	struct digital_poll_tech poll_techs[NFC_DIGITAL_POLL_MODE_COUNT_MAX];

	u8 poll_tech_count;

	u8 poll_tech_index;

	struct mutex poll_lock;



	struct work_struct cmd_work;

	struct work_struct cmd_complete_work;

	struct list_head cmd_queue;

	struct mutex cmd_lock;



	struct work_struct poll_work;



	u8 curr_protocol;

	u8 curr_rf_tech;

	u8 curr_nfc_dep_pni;

};



struct nfc_digital_dev *nfc_digital_allocate_device(struct nfc_digital_ops *ops,

net/nfc/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -10,4 +10,4 @@ obj-$(CONFIG_NFC_DIGITAL) += nfc_digital.o 
nfc-objs := core.o netlink.o af_nfc.o rawsock.o llcp_core.o llcp_commands.o \

		llcp_sock.o



nfc_digital-objs := digital_core.o
 
nfc_digital-objs := digital_core.o digital_technology.o

net/nfc/digital.h

+29 −0
Original line number Diff line number Diff line
@@ -24,4 +24,33 @@ 
#define PROTOCOL_ERR(req) pr_err("%s:%d: NFC Digital Protocol error: %s\n", \

				 __func__, __LINE__, req)



#define DIGITAL_CMD_IN_SEND        0

#define DIGITAL_CMD_TG_SEND        1

#define DIGITAL_CMD_TG_LISTEN      2

#define DIGITAL_CMD_TG_LISTEN_MDAA 3



#define DIGITAL_MAX_HEADER_LEN 7

#define DIGITAL_CRC_LEN        2



struct sk_buff *digital_skb_alloc(struct nfc_digital_dev *ddev,

				  unsigned int len);



int digital_send_cmd(struct nfc_digital_dev *ddev, u8 cmd_type,

		     struct sk_buff *skb, u16 timeout,

		     nfc_digital_cmd_complete_t cmd_cb, void *cb_context);



int digital_in_configure_hw(struct nfc_digital_dev *ddev, int type, int param);

static inline int digital_in_send_cmd(struct nfc_digital_dev *ddev,

				      struct sk_buff *skb, u16 timeout,

				      nfc_digital_cmd_complete_t cmd_cb,

				      void *cb_context)

{

	return digital_send_cmd(ddev, DIGITAL_CMD_IN_SEND, skb, timeout, cmd_cb,

				cb_context);

}



void digital_poll_next_tech(struct nfc_digital_dev *ddev);



int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech);



#endif /* __DIGITAL_H */

net/nfc/digital_core.c

+333 −7
Original line number Diff line number Diff line
@@ -17,24 +17,319 @@ 


#include "digital.h"



#define DIGITAL_PROTO_NFCA_RF_TECH \

	(NFC_PROTO_JEWEL_MASK | NFC_PROTO_MIFARE_MASK)



struct digital_cmd {

	struct list_head queue;



	u8 type;

	u8 pending;



	u16 timeout;

	struct sk_buff *req;

	struct sk_buff *resp;



	nfc_digital_cmd_complete_t cmd_cb;

	void *cb_context;

};



struct sk_buff *digital_skb_alloc(struct nfc_digital_dev *ddev,

				  unsigned int len)

{

	struct sk_buff *skb;



	skb = alloc_skb(len + ddev->tx_headroom + ddev->tx_tailroom,

			GFP_KERNEL);

	if (skb)

		skb_reserve(skb, ddev->tx_headroom);



	return skb;

}



static inline void digital_switch_rf(struct nfc_digital_dev *ddev, bool on)

{

	ddev->ops->switch_rf(ddev, on);

}



static inline void digital_abort_cmd(struct nfc_digital_dev *ddev)

{

	ddev->ops->abort_cmd(ddev);

}



static void digital_wq_cmd_complete(struct work_struct *work)

{

	struct digital_cmd *cmd;

	struct nfc_digital_dev *ddev = container_of(work,

						    struct nfc_digital_dev,

						    cmd_complete_work);



	mutex_lock(&ddev->cmd_lock);



	cmd = list_first_entry_or_null(&ddev->cmd_queue, struct digital_cmd,

				       queue);

	if (!cmd) {

		mutex_unlock(&ddev->cmd_lock);

		return;

	}



	list_del(&cmd->queue);



	mutex_unlock(&ddev->cmd_lock);



	if (!IS_ERR(cmd->resp))

		print_hex_dump_debug("DIGITAL RX: ", DUMP_PREFIX_NONE, 16, 1,

				     cmd->resp->data, cmd->resp->len, false);



	cmd->cmd_cb(ddev, cmd->cb_context, cmd->resp);



	kfree(cmd);



	schedule_work(&ddev->cmd_work);

}



static void digital_send_cmd_complete(struct nfc_digital_dev *ddev,

				      void *arg, struct sk_buff *resp)

{

	struct digital_cmd *cmd = arg;



	cmd->resp = resp;



	schedule_work(&ddev->cmd_complete_work);

}



static void digital_wq_cmd(struct work_struct *work)

{

	int rc;

	struct digital_cmd *cmd;

	struct nfc_digital_dev *ddev = container_of(work,

						    struct nfc_digital_dev,

						    cmd_work);



	mutex_lock(&ddev->cmd_lock);



	cmd = list_first_entry_or_null(&ddev->cmd_queue, struct digital_cmd,

				       queue);

	if (!cmd || cmd->pending) {

		mutex_unlock(&ddev->cmd_lock);

		return;

	}



	mutex_unlock(&ddev->cmd_lock);



	if (cmd->req)

		print_hex_dump_debug("DIGITAL TX: ", DUMP_PREFIX_NONE, 16, 1,

				     cmd->req->data, cmd->req->len, false);



	switch (cmd->type) {

	case DIGITAL_CMD_IN_SEND:

		rc = ddev->ops->in_send_cmd(ddev, cmd->req, cmd->timeout,

					    digital_send_cmd_complete, cmd);

		break;

	default:

		PR_ERR("Unknown cmd type %d", cmd->type);

		return;

	}



	if (!rc)

		return;



	PR_ERR("in_send_command returned err %d", rc);



	mutex_lock(&ddev->cmd_lock);

	list_del(&cmd->queue);

	mutex_unlock(&ddev->cmd_lock);



	kfree_skb(cmd->req);

	kfree(cmd);



	schedule_work(&ddev->cmd_work);

}



int digital_send_cmd(struct nfc_digital_dev *ddev, u8 cmd_type,

		     struct sk_buff *skb, u16 timeout,

		     nfc_digital_cmd_complete_t cmd_cb, void *cb_context)

{

	struct digital_cmd *cmd;



	cmd = kzalloc(sizeof(struct digital_cmd), GFP_KERNEL);

	if (!cmd)

		return -ENOMEM;



	cmd->type = cmd_type;

	cmd->timeout = timeout;

	cmd->req = skb;

	cmd->cmd_cb = cmd_cb;

	cmd->cb_context = cb_context;

	INIT_LIST_HEAD(&cmd->queue);



	mutex_lock(&ddev->cmd_lock);

	list_add_tail(&cmd->queue, &ddev->cmd_queue);

	mutex_unlock(&ddev->cmd_lock);



	schedule_work(&ddev->cmd_work);



	return 0;

}



int digital_in_configure_hw(struct nfc_digital_dev *ddev, int type, int param)

{

	int rc;



	rc = ddev->ops->in_configure_hw(ddev, type, param);

	if (rc)

		PR_ERR("in_configure_hw failed: %d", rc);



	return rc;

}



void digital_poll_next_tech(struct nfc_digital_dev *ddev)

{

	digital_switch_rf(ddev, 0);



	mutex_lock(&ddev->poll_lock);



	if (!ddev->poll_tech_count) {

		mutex_unlock(&ddev->poll_lock);

		return;

	}



	ddev->poll_tech_index = (ddev->poll_tech_index + 1) %

				ddev->poll_tech_count;



	mutex_unlock(&ddev->poll_lock);



	schedule_work(&ddev->poll_work);

}



static void digital_wq_poll(struct work_struct *work)

{

	int rc;

	struct digital_poll_tech *poll_tech;

	struct nfc_digital_dev *ddev = container_of(work,

						    struct nfc_digital_dev,

						    poll_work);

	mutex_lock(&ddev->poll_lock);



	if (!ddev->poll_tech_count) {

		mutex_unlock(&ddev->poll_lock);

		return;

	}



	poll_tech = &ddev->poll_techs[ddev->poll_tech_index];



	mutex_unlock(&ddev->poll_lock);



	rc = poll_tech->poll_func(ddev, poll_tech->rf_tech);

	if (rc)

		digital_poll_next_tech(ddev);

}



static void digital_add_poll_tech(struct nfc_digital_dev *ddev, u8 rf_tech,

				  digital_poll_t poll_func)

{

	struct digital_poll_tech *poll_tech;



	if (ddev->poll_tech_count >= NFC_DIGITAL_POLL_MODE_COUNT_MAX)

		return;



	poll_tech = &ddev->poll_techs[ddev->poll_tech_count++];



	poll_tech->rf_tech = rf_tech;

	poll_tech->poll_func = poll_func;

}



/**

 * start_poll operation

 *

 * For every supported protocol, the corresponding polling function is added

 * to the table of polling technologies (ddev->poll_techs[]) using

 * digital_add_poll_tech().

 * When a polling function fails (by timeout or protocol error) the next one is

 * schedule by digital_poll_next_tech() on the poll workqueue (ddev->poll_work).

 */

static int digital_start_poll(struct nfc_dev *nfc_dev, __u32 im_protocols,

			      __u32 tm_protocols)

{

	return -EOPNOTSUPP;

	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);

	u32 matching_im_protocols, matching_tm_protocols;



	PR_DBG("protocols: im 0x%x, tm 0x%x, supported 0x%x", im_protocols,

	       tm_protocols, ddev->protocols);



	matching_im_protocols = ddev->protocols & im_protocols;

	matching_tm_protocols = ddev->protocols & tm_protocols;



	if (!matching_im_protocols && !matching_tm_protocols) {

		PR_ERR("No known protocol");

		return -EINVAL;

	}



	if (ddev->poll_tech_count) {

		PR_ERR("Already polling");

		return -EBUSY;

	}



	if (ddev->curr_protocol) {

		PR_ERR("A target is already active");

		return -EBUSY;

	}



	ddev->poll_tech_count = 0;

	ddev->poll_tech_index = 0;



	if (matching_im_protocols & DIGITAL_PROTO_NFCA_RF_TECH)

		digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_106A,

				      digital_in_send_sens_req);



	if (!ddev->poll_tech_count) {

		PR_ERR("Unsupported protocols: im=0x%x, tm=0x%x",

		       matching_im_protocols, matching_tm_protocols);

		return -EINVAL;

	}



	schedule_work(&ddev->poll_work);



	return 0;

}



static void digital_stop_poll(struct nfc_dev *nfc_dev)

{

	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);



	mutex_lock(&ddev->poll_lock);



	if (!ddev->poll_tech_count) {

		PR_ERR("Polling operation was not running");

		mutex_unlock(&ddev->poll_lock);

		return;

	}



	ddev->poll_tech_count = 0;



	mutex_unlock(&ddev->poll_lock);



	cancel_work_sync(&ddev->poll_work);



	digital_abort_cmd(ddev);

}



static int digital_dev_up(struct nfc_dev *nfc_dev)

{

	return -EOPNOTSUPP;

	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);



	digital_switch_rf(ddev, 1);



	return 0;

}



static int digital_dev_down(struct nfc_dev *nfc_dev)

{

	return -EOPNOTSUPP;

	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);



	digital_switch_rf(ddev, 0);



	return 0;

}



static int digital_dep_link_up(struct nfc_dev *nfc_dev,
@@ -52,12 +347,15 @@ static int digital_dep_link_down(struct nfc_dev *nfc_dev) 
static int digital_activate_target(struct nfc_dev *nfc_dev,

				   struct nfc_target *target, __u32 protocol)

{

	return -EOPNOTSUPP;

	return 0;

}



static void digital_deactivate_target(struct nfc_dev *nfc_dev,

				      struct nfc_target *target)

{

	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);



	ddev->curr_protocol = 0;

}



static int digital_tg_send(struct nfc_dev *dev, struct sk_buff *skb)
@@ -106,8 +404,22 @@ struct nfc_digital_dev *nfc_digital_allocate_device(struct nfc_digital_ops *ops, 
	ddev->driver_capabilities = driver_capabilities;

	ddev->ops = ops;



	ddev->tx_headroom = tx_headroom;

	ddev->tx_tailroom = tx_tailroom;

	mutex_init(&ddev->cmd_lock);

	INIT_LIST_HEAD(&ddev->cmd_queue);



	INIT_WORK(&ddev->cmd_work, digital_wq_cmd);

	INIT_WORK(&ddev->cmd_complete_work, digital_wq_cmd_complete);



	mutex_init(&ddev->poll_lock);

	INIT_WORK(&ddev->poll_work, digital_wq_poll);



	if (supported_protocols & NFC_PROTO_JEWEL_MASK)

		ddev->protocols |= NFC_PROTO_JEWEL_MASK;

	if (supported_protocols & NFC_PROTO_MIFARE_MASK)

		ddev->protocols |= NFC_PROTO_MIFARE_MASK;



	ddev->tx_headroom = tx_headroom + DIGITAL_MAX_HEADER_LEN;

	ddev->tx_tailroom = tx_tailroom + DIGITAL_CRC_LEN;



	ddev->nfc_dev = nfc_allocate_device(&digital_nfc_ops, ddev->protocols,

					    ddev->tx_headroom,
@@ -131,7 +443,6 @@ EXPORT_SYMBOL(nfc_digital_allocate_device); 
void nfc_digital_free_device(struct nfc_digital_dev *ddev)

{

	nfc_free_device(ddev->nfc_dev);



	kfree(ddev);

}

EXPORT_SYMBOL(nfc_digital_free_device);
@@ -144,7 +455,22 @@ EXPORT_SYMBOL(nfc_digital_register_device); 


void nfc_digital_unregister_device(struct nfc_digital_dev *ddev)

{

	struct digital_cmd *cmd, *n;



	nfc_unregister_device(ddev->nfc_dev);



	mutex_lock(&ddev->poll_lock);

	ddev->poll_tech_count = 0;

	mutex_unlock(&ddev->poll_lock);



	cancel_work_sync(&ddev->poll_work);

	cancel_work_sync(&ddev->cmd_work);

	cancel_work_sync(&ddev->cmd_complete_work);



	list_for_each_entry_safe(cmd, n, &ddev->cmd_queue, queue) {

		list_del(&cmd->queue);

		kfree(cmd);

	}

}

EXPORT_SYMBOL(nfc_digital_unregister_device);

net/nfc/digital_technology.c

0 → 100644
+64 −0
Original line number Diff line number Diff line 
/*

 * NFC Digital Protocol stack

 * Copyright (c) 2013, Intel Corporation.

 *

 * 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 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.

 *

 */



#include "digital.h"



#define DIGITAL_CMD_SENS_REQ    0x26

#define DIGITAL_CMD_ALL_REQ     0x52

#define DIGITAL_CMD_SEL_REQ_CL1 0x93

#define DIGITAL_CMD_SEL_REQ_CL2 0x95

#define DIGITAL_CMD_SEL_REQ_CL3 0x97



#define DIGITAL_SDD_REQ_SEL_PAR 0x20



#define DIGITAL_SDD_RES_CT  0x88

#define DIGITAL_SDD_RES_LEN 5



static void digital_in_recv_sens_res(struct nfc_digital_dev *ddev, void *arg,

				     struct sk_buff *resp)

{

	if (!IS_ERR(resp))

		dev_kfree_skb(resp);



	digital_poll_next_tech(ddev);

}



int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech)

{

	struct sk_buff *skb;

	int rc;



	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,

				     NFC_DIGITAL_RF_TECH_106A);

	if (rc)

		return rc;



	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,

				     NFC_DIGITAL_FRAMING_NFCA_SHORT);

	if (rc)

		return rc;



	skb = digital_skb_alloc(ddev, 1);

	if (!skb)

		return -ENOMEM;



	*skb_put(skb, sizeof(u8)) = DIGITAL_CMD_SENS_REQ;



	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sens_res, NULL);

	if (rc)

		kfree_skb(skb);



	return rc;

}