405 lines
9.1 KiB
C
405 lines
9.1 KiB
C
/*
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* SPI Link Layer for ST NCI based Driver
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* Copyright (C) 2014-2015 STMicroelectronics SAS. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/spi/spi.h>
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#include <linux/gpio.h>
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#include <linux/of_irq.h>
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#include <linux/of_gpio.h>
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#include <linux/interrupt.h>
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#include <linux/delay.h>
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#include <linux/nfc.h>
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#include <net/nfc/nci.h>
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#include <linux/platform_data/st-nci.h>
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#include "st-nci.h"
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#define DRIVER_DESC "NCI NFC driver for ST_NCI"
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/* ndlc header */
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#define ST_NCI_FRAME_HEADROOM 1
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#define ST_NCI_FRAME_TAILROOM 0
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#define ST_NCI_SPI_MIN_SIZE 4 /* PCB(1) + NCI Packet header(3) */
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#define ST_NCI_SPI_MAX_SIZE 250 /* req 4.2.1 */
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#define ST_NCI_SPI_DRIVER_NAME "st_nci_spi"
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static struct spi_device_id st_nci_spi_id_table[] = {
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{ST_NCI_SPI_DRIVER_NAME, 0},
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{}
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};
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MODULE_DEVICE_TABLE(spi, st_nci_spi_id_table);
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struct st_nci_spi_phy {
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struct spi_device *spi_dev;
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struct llt_ndlc *ndlc;
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unsigned int gpio_reset;
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unsigned int irq_polarity;
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struct st_nci_se_status se_status;
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};
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#define SPI_DUMP_SKB(info, skb) \
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do { \
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pr_debug("%s:\n", info); \
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print_hex_dump(KERN_DEBUG, "spi: ", DUMP_PREFIX_OFFSET, \
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16, 1, (skb)->data, (skb)->len, 0); \
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} while (0)
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static int st_nci_spi_enable(void *phy_id)
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{
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struct st_nci_spi_phy *phy = phy_id;
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gpio_set_value(phy->gpio_reset, 0);
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usleep_range(10000, 15000);
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gpio_set_value(phy->gpio_reset, 1);
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usleep_range(80000, 85000);
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if (phy->ndlc->powered == 0)
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enable_irq(phy->spi_dev->irq);
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return 0;
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}
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static void st_nci_spi_disable(void *phy_id)
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{
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struct st_nci_spi_phy *phy = phy_id;
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disable_irq_nosync(phy->spi_dev->irq);
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}
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/*
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* Writing a frame must not return the number of written bytes.
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* It must return either zero for success, or <0 for error.
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* In addition, it must not alter the skb
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*/
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static int st_nci_spi_write(void *phy_id, struct sk_buff *skb)
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{
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int r;
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struct st_nci_spi_phy *phy = phy_id;
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struct spi_device *dev = phy->spi_dev;
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struct sk_buff *skb_rx;
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u8 buf[ST_NCI_SPI_MAX_SIZE + NCI_DATA_HDR_SIZE +
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ST_NCI_FRAME_HEADROOM + ST_NCI_FRAME_TAILROOM];
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struct spi_transfer spi_xfer = {
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.tx_buf = skb->data,
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.rx_buf = buf,
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.len = skb->len,
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};
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SPI_DUMP_SKB("st_nci_spi_write", skb);
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if (phy->ndlc->hard_fault != 0)
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return phy->ndlc->hard_fault;
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r = spi_sync_transfer(dev, &spi_xfer, 1);
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/*
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* We may have received some valuable data on miso line.
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* Send them back in the ndlc state machine.
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*/
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if (!r) {
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skb_rx = alloc_skb(skb->len, GFP_KERNEL);
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if (!skb_rx) {
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r = -ENOMEM;
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goto exit;
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}
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skb_put(skb_rx, skb->len);
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memcpy(skb_rx->data, buf, skb->len);
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ndlc_recv(phy->ndlc, skb_rx);
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}
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exit:
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return r;
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}
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/*
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* Reads an ndlc frame and returns it in a newly allocated sk_buff.
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* returns:
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* 0 : if received frame is complete
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* -EREMOTEIO : i2c read error (fatal)
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* -EBADMSG : frame was incorrect and discarded
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* -ENOMEM : cannot allocate skb, frame dropped
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*/
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static int st_nci_spi_read(struct st_nci_spi_phy *phy,
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struct sk_buff **skb)
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{
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int r;
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u8 len;
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u8 buf[ST_NCI_SPI_MAX_SIZE];
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struct spi_device *dev = phy->spi_dev;
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struct spi_transfer spi_xfer = {
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.rx_buf = buf,
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.len = ST_NCI_SPI_MIN_SIZE,
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};
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r = spi_sync_transfer(dev, &spi_xfer, 1);
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if (r < 0)
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return -EREMOTEIO;
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len = be16_to_cpu(*(__be16 *) (buf + 2));
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if (len > ST_NCI_SPI_MAX_SIZE) {
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nfc_err(&dev->dev, "invalid frame len\n");
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phy->ndlc->hard_fault = 1;
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return -EBADMSG;
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}
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*skb = alloc_skb(ST_NCI_SPI_MIN_SIZE + len, GFP_KERNEL);
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if (*skb == NULL)
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return -ENOMEM;
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skb_reserve(*skb, ST_NCI_SPI_MIN_SIZE);
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skb_put(*skb, ST_NCI_SPI_MIN_SIZE);
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memcpy((*skb)->data, buf, ST_NCI_SPI_MIN_SIZE);
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if (!len)
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return 0;
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spi_xfer.len = len;
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r = spi_sync_transfer(dev, &spi_xfer, 1);
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if (r < 0) {
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kfree_skb(*skb);
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return -EREMOTEIO;
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}
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skb_put(*skb, len);
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memcpy((*skb)->data + ST_NCI_SPI_MIN_SIZE, buf, len);
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SPI_DUMP_SKB("spi frame read", *skb);
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return 0;
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}
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/*
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* Reads an ndlc frame from the chip.
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*
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* On ST21NFCB, IRQ goes in idle state when read starts.
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*/
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static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id)
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{
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struct st_nci_spi_phy *phy = phy_id;
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struct spi_device *dev;
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struct sk_buff *skb = NULL;
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int r;
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if (!phy || !phy->ndlc || irq != phy->spi_dev->irq) {
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WARN_ON_ONCE(1);
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return IRQ_NONE;
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}
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dev = phy->spi_dev;
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dev_dbg(&dev->dev, "IRQ\n");
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if (phy->ndlc->hard_fault)
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return IRQ_HANDLED;
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if (!phy->ndlc->powered) {
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st_nci_spi_disable(phy);
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return IRQ_HANDLED;
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}
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r = st_nci_spi_read(phy, &skb);
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if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
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return IRQ_HANDLED;
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ndlc_recv(phy->ndlc, skb);
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return IRQ_HANDLED;
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}
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static struct nfc_phy_ops spi_phy_ops = {
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.write = st_nci_spi_write,
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.enable = st_nci_spi_enable,
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.disable = st_nci_spi_disable,
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};
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#ifdef CONFIG_OF
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static int st_nci_spi_of_request_resources(struct spi_device *dev)
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{
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struct st_nci_spi_phy *phy = spi_get_drvdata(dev);
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struct device_node *pp;
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int gpio;
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int r;
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pp = dev->dev.of_node;
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if (!pp)
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return -ENODEV;
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/* Get GPIO from device tree */
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gpio = of_get_named_gpio(pp, "reset-gpios", 0);
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if (gpio < 0) {
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nfc_err(&dev->dev,
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"Failed to retrieve reset-gpios from device tree\n");
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return gpio;
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}
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/* GPIO request and configuration */
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r = devm_gpio_request_one(&dev->dev, gpio,
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GPIOF_OUT_INIT_HIGH, "clf_reset");
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if (r) {
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nfc_err(&dev->dev, "Failed to request reset pin\n");
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return r;
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}
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phy->gpio_reset = gpio;
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phy->irq_polarity = irq_get_trigger_type(dev->irq);
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phy->se_status.is_ese_present =
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of_property_read_bool(pp, "ese-present");
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phy->se_status.is_uicc_present =
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of_property_read_bool(pp, "uicc-present");
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return 0;
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}
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#else
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static int st_nci_spi_of_request_resources(struct spi_device *dev)
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{
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return -ENODEV;
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}
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#endif
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static int st_nci_spi_request_resources(struct spi_device *dev)
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{
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struct st_nci_nfc_platform_data *pdata;
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struct st_nci_spi_phy *phy = spi_get_drvdata(dev);
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int r;
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pdata = dev->dev.platform_data;
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if (pdata == NULL) {
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nfc_err(&dev->dev, "No platform data\n");
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return -EINVAL;
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}
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/* store for later use */
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phy->gpio_reset = pdata->gpio_reset;
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phy->irq_polarity = pdata->irq_polarity;
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r = devm_gpio_request_one(&dev->dev,
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phy->gpio_reset, GPIOF_OUT_INIT_HIGH, "clf_reset");
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if (r) {
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pr_err("%s : reset gpio_request failed\n", __FILE__);
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return r;
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}
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phy->se_status.is_ese_present = pdata->is_ese_present;
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phy->se_status.is_uicc_present = pdata->is_uicc_present;
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return 0;
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}
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static int st_nci_spi_probe(struct spi_device *dev)
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{
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struct st_nci_spi_phy *phy;
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struct st_nci_nfc_platform_data *pdata;
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int r;
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dev_dbg(&dev->dev, "%s\n", __func__);
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dev_dbg(&dev->dev, "IRQ: %d\n", dev->irq);
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/* Check SPI platform functionnalities */
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if (!dev) {
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pr_debug("%s: dev is NULL. Device is not accessible.\n",
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__func__);
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return -ENODEV;
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}
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phy = devm_kzalloc(&dev->dev, sizeof(struct st_nci_spi_phy),
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GFP_KERNEL);
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if (!phy)
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return -ENOMEM;
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phy->spi_dev = dev;
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spi_set_drvdata(dev, phy);
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pdata = dev->dev.platform_data;
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if (!pdata && dev->dev.of_node) {
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r = st_nci_spi_of_request_resources(dev);
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if (r) {
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nfc_err(&dev->dev, "No platform data\n");
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return r;
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}
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} else if (pdata) {
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r = st_nci_spi_request_resources(dev);
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if (r) {
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nfc_err(&dev->dev,
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"Cannot get platform resources\n");
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return r;
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}
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} else {
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nfc_err(&dev->dev,
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"st_nci platform resources not available\n");
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return -ENODEV;
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}
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r = ndlc_probe(phy, &spi_phy_ops, &dev->dev,
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ST_NCI_FRAME_HEADROOM, ST_NCI_FRAME_TAILROOM,
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&phy->ndlc, &phy->se_status);
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if (r < 0) {
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nfc_err(&dev->dev, "Unable to register ndlc layer\n");
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return r;
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}
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r = devm_request_threaded_irq(&dev->dev, dev->irq, NULL,
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st_nci_irq_thread_fn,
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phy->irq_polarity | IRQF_ONESHOT,
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ST_NCI_SPI_DRIVER_NAME, phy);
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if (r < 0)
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nfc_err(&dev->dev, "Unable to register IRQ handler\n");
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return r;
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}
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static int st_nci_spi_remove(struct spi_device *dev)
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{
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struct st_nci_spi_phy *phy = spi_get_drvdata(dev);
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dev_dbg(&dev->dev, "%s\n", __func__);
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ndlc_remove(phy->ndlc);
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return 0;
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}
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#ifdef CONFIG_OF
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static const struct of_device_id of_st_nci_spi_match[] = {
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{ .compatible = "st,st21nfcb-spi", },
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{}
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};
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MODULE_DEVICE_TABLE(of, of_st_nci_spi_match);
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#endif
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static struct spi_driver st_nci_spi_driver = {
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.driver = {
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.owner = THIS_MODULE,
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.name = ST_NCI_SPI_DRIVER_NAME,
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.of_match_table = of_match_ptr(of_st_nci_spi_match),
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},
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.probe = st_nci_spi_probe,
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.id_table = st_nci_spi_id_table,
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.remove = st_nci_spi_remove,
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};
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module_spi_driver(st_nci_spi_driver);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION(DRIVER_DESC);
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