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a0386bba70
The value returned by an spi driver's remove function is mostly ignored. (Only an error message is printed if the value is non-zero that the error is ignored.) So change the prototype of the remove function to return no value. This way driver authors are not tempted to assume that passing an error to the upper layer is a good idea. All drivers are adapted accordingly. There is no intended change of behaviour, all callbacks were prepared to return 0 before. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com> Acked-by: Miquel Raynal <miquel.raynal@bootlin.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Claudius Heine <ch@denx.de> Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC Acked-by: Marcus Folkesson <marcus.folkesson@gmail.com> Acked-by: Łukasz Stelmach <l.stelmach@samsung.com> Acked-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
306 lines
6.9 KiB
C
306 lines
6.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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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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#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/consumer.h>
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#include <linux/acpi.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 <linux/of.h>
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#include <net/nfc/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_DRIVER_NAME "st_nci"
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#define ST_NCI_SPI_DRIVER_NAME "st_nci_spi"
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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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bool irq_active;
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struct gpio_desc *gpiod_reset;
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struct st_nci_se_status se_status;
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};
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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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gpiod_set_value(phy->gpiod_reset, 0);
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usleep_range(10000, 15000);
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gpiod_set_value(phy->gpiod_reset, 1);
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usleep_range(80000, 85000);
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if (phy->ndlc->powered == 0 && phy->irq_active == 0) {
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enable_irq(phy->spi_dev->irq);
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phy->irq_active = true;
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}
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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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phy->irq_active = false;
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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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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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return -ENOMEM;
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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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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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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 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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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 const 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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static const struct acpi_gpio_params reset_gpios = { 1, 0, false };
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static const struct acpi_gpio_mapping acpi_st_nci_gpios[] = {
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{ "reset-gpios", &reset_gpios, 1 },
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{},
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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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int r;
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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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r = devm_acpi_dev_add_driver_gpios(&dev->dev, acpi_st_nci_gpios);
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if (r)
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dev_dbg(&dev->dev, "Unable to add GPIO mapping table\n");
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/* Get RESET GPIO */
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phy->gpiod_reset = devm_gpiod_get(&dev->dev, "reset", GPIOD_OUT_HIGH);
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if (IS_ERR(phy->gpiod_reset)) {
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nfc_err(&dev->dev, "Unable to get RESET GPIO\n");
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return PTR_ERR(phy->gpiod_reset);
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}
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phy->se_status.is_ese_present =
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device_property_read_bool(&dev->dev, "ese-present");
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phy->se_status.is_uicc_present =
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device_property_read_bool(&dev->dev, "uicc-present");
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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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phy->irq_active = true;
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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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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 void 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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ndlc_remove(phy->ndlc);
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}
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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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{"st21nfcb-spi", 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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static const struct acpi_device_id st_nci_spi_acpi_match[] __maybe_unused = {
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{"SMO2101", 0},
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{}
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};
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MODULE_DEVICE_TABLE(acpi, st_nci_spi_acpi_match);
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static const struct of_device_id of_st_nci_spi_match[] __maybe_unused = {
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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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static struct spi_driver st_nci_spi_driver = {
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.driver = {
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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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.acpi_match_table = ACPI_PTR(st_nci_spi_acpi_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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