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Release 4.14 drivers/nfc/st-nci/spi.c

/*
 * SPI Link Layer for ST NCI based Driver
 * Copyright (C) 2014-2015 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/module.h>
#include <linux/spi/spi.h>
#include <linux/gpio/consumer.h>
#include <linux/acpi.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/nfc.h>
#include <linux/of.h>
#include <net/nfc/nci.h>

#include "st-nci.h"


#define DRIVER_DESC "NCI NFC driver for ST_NCI"

/* ndlc header */

#define ST_NCI_FRAME_HEADROOM	1

#define ST_NCI_FRAME_TAILROOM	0


#define ST_NCI_SPI_MIN_SIZE 4   
/* PCB(1) + NCI Packet header(3) */

#define ST_NCI_SPI_MAX_SIZE 250 
/* req 4.2.1 */


#define ST_NCI_DRIVER_NAME "st_nci"

#define ST_NCI_SPI_DRIVER_NAME "st_nci_spi"


struct st_nci_spi_phy {
	
struct spi_device *spi_dev;
	
struct llt_ndlc *ndlc;

	
bool irq_active;

	
struct gpio_desc *gpiod_reset;

	
struct st_nci_se_status se_status;
};


static int st_nci_spi_enable(void *phy_id) { struct st_nci_spi_phy *phy = phy_id; gpiod_set_value(phy->gpiod_reset, 0); usleep_range(10000, 15000); gpiod_set_value(phy->gpiod_reset, 1); usleep_range(80000, 85000); if (phy->ndlc->powered == 0 && phy->irq_active == 0) { enable_irq(phy->spi_dev->irq); phy->irq_active = true; } return 0; }

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Christophe Ricard8195.29%266.67%
Andy Shevchenko44.71%133.33%
Total85100.00%3100.00%


static void st_nci_spi_disable(void *phy_id) { struct st_nci_spi_phy *phy = phy_id; disable_irq_nosync(phy->spi_dev->irq); phy->irq_active = false; }

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Christophe Ricard32100.00%2100.00%
Total32100.00%2100.00%

/* * 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 st_nci_spi_write(void *phy_id, struct sk_buff *skb) { int r; struct st_nci_spi_phy *phy = phy_id; struct spi_device *dev = phy->spi_dev; struct sk_buff *skb_rx; u8 buf[ST_NCI_SPI_MAX_SIZE + NCI_DATA_HDR_SIZE + ST_NCI_FRAME_HEADROOM + ST_NCI_FRAME_TAILROOM]; struct spi_transfer spi_xfer = { .tx_buf = skb->data, .rx_buf = buf, .len = skb->len, }; if (phy->ndlc->hard_fault != 0) return phy->ndlc->hard_fault; r = spi_sync_transfer(dev, &spi_xfer, 1); /* * We may have received some valuable data on miso line. * Send them back in the ndlc state machine. */ if (!r) { skb_rx = alloc_skb(skb->len, GFP_KERNEL); if (!skb_rx) { r = -ENOMEM; goto exit; } skb_put(skb_rx, skb->len); memcpy(skb_rx->data, buf, skb->len); ndlc_recv(phy->ndlc, skb_rx); } exit: return r; }

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Christophe Ricard175100.00%2100.00%
Total175100.00%2100.00%

/* * Reads an ndlc frame and returns it in a newly allocated sk_buff. * returns: * 0 : if received frame is complete * -EREMOTEIO : i2c read error (fatal) * -EBADMSG : frame was incorrect and discarded * -ENOMEM : cannot allocate skb, frame dropped */
static int st_nci_spi_read(struct st_nci_spi_phy *phy, struct sk_buff **skb) { int r; u8 len; u8 buf[ST_NCI_SPI_MAX_SIZE]; struct spi_device *dev = phy->spi_dev; struct spi_transfer spi_xfer = { .rx_buf = buf, .len = ST_NCI_SPI_MIN_SIZE, }; r = spi_sync_transfer(dev, &spi_xfer, 1); if (r < 0) return -EREMOTEIO; len = be16_to_cpu(*(__be16 *) (buf + 2)); if (len > ST_NCI_SPI_MAX_SIZE) { nfc_err(&dev->dev, "invalid frame len\n"); phy->ndlc->hard_fault = 1; return -EBADMSG; } *skb = alloc_skb(ST_NCI_SPI_MIN_SIZE + len, GFP_KERNEL); if (*skb == NULL) return -ENOMEM; skb_reserve(*skb, ST_NCI_SPI_MIN_SIZE); skb_put(*skb, ST_NCI_SPI_MIN_SIZE); memcpy((*skb)->data, buf, ST_NCI_SPI_MIN_SIZE); if (!len) return 0; spi_xfer.len = len; r = spi_sync_transfer(dev, &spi_xfer, 1); if (r < 0) { kfree_skb(*skb); return -EREMOTEIO; } skb_put(*skb, len); memcpy((*skb)->data + ST_NCI_SPI_MIN_SIZE, buf, len); return 0; }

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Christophe Ricard246100.00%1100.00%
Total246100.00%1100.00%

/* * Reads an ndlc frame from the chip. * * On ST21NFCB, IRQ goes in idle state when read starts. */
static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id) { struct st_nci_spi_phy *phy = phy_id; struct spi_device *dev; struct sk_buff *skb = NULL; int r; if (!phy || !phy->ndlc || irq != phy->spi_dev->irq) { WARN_ON_ONCE(1); return IRQ_NONE; } dev = phy->spi_dev; dev_dbg(&dev->dev, "IRQ\n"); if (phy->ndlc->hard_fault) return IRQ_HANDLED; if (!phy->ndlc->powered) { st_nci_spi_disable(phy); return IRQ_HANDLED; } r = st_nci_spi_read(phy, &skb); if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG) return IRQ_HANDLED; ndlc_recv(phy->ndlc, skb); return IRQ_HANDLED; }

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Christophe Ricard151100.00%1100.00%
Total151100.00%1100.00%

static struct nfc_phy_ops spi_phy_ops = { .write = st_nci_spi_write, .enable = st_nci_spi_enable, .disable = st_nci_spi_disable, }; static const struct acpi_gpio_params reset_gpios = { 1, 0, false }; static const struct acpi_gpio_mapping acpi_st_nci_gpios[] = { { "reset-gpios", &reset_gpios, 1 }, {}, };
static int st_nci_spi_probe(struct spi_device *dev) { struct st_nci_spi_phy *phy; int r; dev_dbg(&dev->dev, "%s\n", __func__); dev_dbg(&dev->dev, "IRQ: %d\n", dev->irq); /* Check SPI platform functionnalities */ if (!dev) { pr_debug("%s: dev is NULL. Device is not accessible.\n", __func__); return -ENODEV; } phy = devm_kzalloc(&dev->dev, sizeof(struct st_nci_spi_phy), GFP_KERNEL); if (!phy) return -ENOMEM; phy->spi_dev = dev; spi_set_drvdata(dev, phy); r = devm_acpi_dev_add_driver_gpios(&dev->dev, acpi_st_nci_gpios); if (r) dev_dbg(&dev->dev, "Unable to add GPIO mapping table\n"); /* Get RESET GPIO */ phy->gpiod_reset = devm_gpiod_get(&dev->dev, "reset", GPIOD_OUT_HIGH); if (IS_ERR(phy->gpiod_reset)) { nfc_err(&dev->dev, "Unable to get RESET GPIO\n"); return PTR_ERR(phy->gpiod_reset); } phy->se_status.is_ese_present = device_property_read_bool(&dev->dev, "ese-present"); phy->se_status.is_uicc_present = device_property_read_bool(&dev->dev, "uicc-present"); r = ndlc_probe(phy, &spi_phy_ops, &dev->dev, ST_NCI_FRAME_HEADROOM, ST_NCI_FRAME_TAILROOM, &phy->ndlc, &phy->se_status); if (r < 0) { nfc_err(&dev->dev, "Unable to register ndlc layer\n"); return r; } phy->irq_active = true; r = devm_request_threaded_irq(&dev->dev, dev->irq, NULL, st_nci_irq_thread_fn, IRQF_ONESHOT, ST_NCI_SPI_DRIVER_NAME, phy); if (r < 0) nfc_err(&dev->dev, "Unable to register IRQ handler\n"); return r; }

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Christophe Ricard24780.46%466.67%
Andy Shevchenko6019.54%233.33%
Total307100.00%6100.00%


static int st_nci_spi_remove(struct spi_device *dev) { struct st_nci_spi_phy *phy = spi_get_drvdata(dev); dev_dbg(&dev->dev, "%s\n", __func__); ndlc_remove(phy->ndlc); return 0; }

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Christophe Ricard43100.00%1100.00%
Total43100.00%1100.00%

static struct spi_device_id st_nci_spi_id_table[] = { {ST_NCI_SPI_DRIVER_NAME, 0}, {} }; MODULE_DEVICE_TABLE(spi, st_nci_spi_id_table); static const struct acpi_device_id st_nci_spi_acpi_match[] = { {"SMO2101", 0}, {} }; MODULE_DEVICE_TABLE(acpi, st_nci_spi_acpi_match); static const struct of_device_id of_st_nci_spi_match[] = { { .compatible = "st,st21nfcb-spi", }, {} }; MODULE_DEVICE_TABLE(of, of_st_nci_spi_match); static struct spi_driver st_nci_spi_driver = { .driver = { .name = ST_NCI_SPI_DRIVER_NAME, .of_match_table = of_match_ptr(of_st_nci_spi_match), .acpi_match_table = ACPI_PTR(st_nci_spi_acpi_match), }, .probe = st_nci_spi_probe, .id_table = st_nci_spi_id_table, .remove = st_nci_spi_remove, }; module_spi_driver(st_nci_spi_driver); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION(DRIVER_DESC);

Overall Contributors

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Christophe Ricard121891.65%758.33%
Andy Shevchenko1118.35%541.67%
Total1329100.00%12100.00%
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