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Commit ade67208 authored by Waldemar Rymarkiewicz's avatar Waldemar Rymarkiewicz Committed by Samuel Ortiz
Browse files

NFC: Remove crc generation from shdlc layer 



Checksum is specific for a chip spcification and it varies
(in size and type) between different hardware. It should be
handled in the driver then.

Moreover, shdlc spec doesn't mention crc as a part of the frame.

Update pn544_hci driver as well.

Signed-off-by: default avatarWaldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Acked-by: default avatarEric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent 52da2449

drivers/nfc/pn544_hci.c

+30 −2
Original line number Diff line number Diff line
@@ -128,6 +128,8 @@ static struct nfc_hci_gate pn544_gates[] = { 


/* Largest headroom needed for outgoing custom commands */

#define PN544_CMDS_HEADROOM	2

#define PN544_FRAME_HEADROOM 1

#define PN544_FRAME_TAILROOM 2



struct pn544_hci_info {

	struct i2c_client *i2c_dev;
@@ -576,15 +578,40 @@ static int pn544_hci_ready(struct nfc_shdlc *shdlc) 
	return 0;

}



static void pn544_hci_add_len_crc(struct sk_buff *skb)

{

	u16 crc;

	int len;



	len = skb->len + 2;

	*skb_push(skb, 1) = len;



	crc = crc_ccitt(0xffff, skb->data, skb->len);

	crc = ~crc;

	*skb_put(skb, 1) = crc & 0xff;

	*skb_put(skb, 1) = crc >> 8;

}



static void pn544_hci_remove_len_crc(struct sk_buff *skb)

{

	skb_pull(skb, PN544_FRAME_HEADROOM);

	skb_trim(skb, PN544_FRAME_TAILROOM);

}



static int pn544_hci_xmit(struct nfc_shdlc *shdlc, struct sk_buff *skb)

{

	struct pn544_hci_info *info = nfc_shdlc_get_clientdata(shdlc);

	struct i2c_client *client = info->i2c_dev;

	int r;



	if (info->hard_fault != 0)

		return info->hard_fault;



	return pn544_hci_i2c_write(client, skb->data, skb->len);

	pn544_hci_add_len_crc(skb);

	r = pn544_hci_i2c_write(client, skb->data, skb->len);

	pn544_hci_remove_len_crc(skb);



	return r;

}



static int pn544_hci_start_poll(struct nfc_shdlc *shdlc,
@@ -874,7 +901,8 @@ static int __devinit pn544_hci_probe(struct i2c_client *client, 


	info->shdlc = nfc_shdlc_allocate(&pn544_shdlc_ops,

					 &init_data, protocols,

					 PN544_CMDS_HEADROOM, 0,

					 PN544_FRAME_HEADROOM + PN544_CMDS_HEADROOM,

					 PN544_FRAME_TAILROOM,

					 PN544_HCI_LLC_MAX_PAYLOAD,

					 dev_name(&client->dev));

	if (!info->shdlc) {

net/nfc/hci/shdlc.c

+2 −25
Original line number Diff line number Diff line
@@ -22,7 +22,6 @@ 
#include <linux/sched.h>

#include <linux/export.h>

#include <linux/wait.h>

#include <linux/crc-ccitt.h>

#include <linux/slab.h>

#include <linux/skbuff.h>
@@ -30,7 +29,6 @@ 
#include <net/nfc/shdlc.h>



#define SHDLC_LLC_HEAD_ROOM	2

#define SHDLC_LLC_TAIL_ROOM	2



#define SHDLC_MAX_WINDOW	4

#define SHDLC_SREJ_SUPPORT	false
@@ -94,28 +92,13 @@ static struct sk_buff *nfc_shdlc_alloc_skb(struct nfc_shdlc *shdlc, 
	struct sk_buff *skb;



	skb = alloc_skb(shdlc->client_headroom + SHDLC_LLC_HEAD_ROOM +

			shdlc->client_tailroom + SHDLC_LLC_TAIL_ROOM +

			payload_len, GFP_KERNEL);

			shdlc->client_tailroom + payload_len, GFP_KERNEL);

	if (skb)

		skb_reserve(skb, shdlc->client_headroom + SHDLC_LLC_HEAD_ROOM);



	return skb;

}



static void nfc_shdlc_add_len_crc(struct sk_buff *skb)

{

	u16 crc;

	int len;



	len = skb->len + 2;

	*skb_push(skb, 1) = len;



	crc = crc_ccitt(0xffff, skb->data, skb->len);

	crc = ~crc;

	*skb_put(skb, 1) = crc & 0xff;

	*skb_put(skb, 1) = crc >> 8;

}



/* immediately sends an S frame. */

static int nfc_shdlc_send_s_frame(struct nfc_shdlc *shdlc,

				  enum sframe_type sframe_type, int nr)
@@ -131,8 +114,6 @@ static int nfc_shdlc_send_s_frame(struct nfc_shdlc *shdlc, 


	*skb_push(skb, 1) = SHDLC_CONTROL_HEAD_S | (sframe_type << 3) | nr;



	nfc_shdlc_add_len_crc(skb);



	r = shdlc->ops->xmit(shdlc, skb);



	kfree_skb(skb);
@@ -151,8 +132,6 @@ static int nfc_shdlc_send_u_frame(struct nfc_shdlc *shdlc, 


	*skb_push(skb, 1) = SHDLC_CONTROL_HEAD_U | uframe_modifier;



	nfc_shdlc_add_len_crc(skb);



	r = shdlc->ops->xmit(shdlc, skb);



	kfree_skb(skb);
@@ -509,8 +488,6 @@ static void nfc_shdlc_handle_send_queue(struct nfc_shdlc *shdlc) 
			 shdlc->nr);

	/*	SHDLC_DUMP_SKB("shdlc frame written", skb); */



		nfc_shdlc_add_len_crc(skb);



		r = shdlc->ops->xmit(shdlc, skb);

		if (r < 0) {

			shdlc->hard_fault = r;
@@ -880,7 +857,7 @@ struct nfc_shdlc *nfc_shdlc_allocate(struct nfc_shdlc_ops *ops, 


	shdlc->hdev = nfc_hci_allocate_device(&shdlc_ops, init_data, protocols,

					      tx_headroom + SHDLC_LLC_HEAD_ROOM,

					      tx_tailroom + SHDLC_LLC_TAIL_ROOM,

					      tx_tailroom,

					      max_link_payload);

	if (shdlc->hdev == NULL)

		goto err_allocdev;