diff options
Diffstat (limited to 'drivers/nfc/nfcmrvl/spi.c')
| -rw-r--r-- | drivers/nfc/nfcmrvl/spi.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/drivers/nfc/nfcmrvl/spi.c b/drivers/nfc/nfcmrvl/spi.c new file mode 100644 index 000000000..ad3359a49 --- /dev/null +++ b/drivers/nfc/nfcmrvl/spi.c @@ -0,0 +1,211 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Marvell NFC-over-SPI driver: SPI interface related functions + * + * Copyright (C) 2015, Marvell International Ltd. + */ + +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/nfc.h> +#include <linux/of_irq.h> +#include <net/nfc/nci.h> +#include <net/nfc/nci_core.h> +#include <linux/spi/spi.h> +#include "nfcmrvl.h" + +#define SPI_WAIT_HANDSHAKE 1 + +struct nfcmrvl_spi_drv_data { + unsigned long flags; + struct spi_device *spi; + struct nci_spi *nci_spi; + struct completion handshake_completion; + struct nfcmrvl_private *priv; +}; + +static irqreturn_t nfcmrvl_spi_int_irq_thread_fn(int irq, void *drv_data_ptr) +{ + struct nfcmrvl_spi_drv_data *drv_data = drv_data_ptr; + struct sk_buff *skb; + + /* + * Special case where we are waiting for SPI_INT deassertion to start a + * transfer. + */ + if (test_and_clear_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags)) { + complete(&drv_data->handshake_completion); + return IRQ_HANDLED; + } + + /* Normal case, SPI_INT deasserted by slave to trigger a master read */ + + skb = nci_spi_read(drv_data->nci_spi); + if (!skb) { + nfc_err(&drv_data->spi->dev, "failed to read spi packet"); + return IRQ_HANDLED; + } + + if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0) + nfc_err(&drv_data->spi->dev, "corrupted RX packet"); + + return IRQ_HANDLED; +} + +static int nfcmrvl_spi_nci_open(struct nfcmrvl_private *priv) +{ + return 0; +} + +static int nfcmrvl_spi_nci_close(struct nfcmrvl_private *priv) +{ + return 0; +} + +static int nfcmrvl_spi_nci_send(struct nfcmrvl_private *priv, + struct sk_buff *skb) +{ + struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data; + int err; + + /* Reinit completion for slave handshake */ + reinit_completion(&drv_data->handshake_completion); + set_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags); + + /* + * Append a dummy byte at the end of SPI frame. This is due to a + * specific DMA implementation in the controller + */ + skb_put(skb, 1); + + /* Send the SPI packet */ + err = nci_spi_send(drv_data->nci_spi, &drv_data->handshake_completion, + skb); + if (err) + nfc_err(priv->dev, "spi_send failed %d", err); + + return err; +} + +static void nfcmrvl_spi_nci_update_config(struct nfcmrvl_private *priv, + const void *param) +{ + struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data; + const struct nfcmrvl_fw_spi_config *config = param; + + drv_data->nci_spi->xfer_speed_hz = config->clk; +} + +static const struct nfcmrvl_if_ops spi_ops = { + .nci_open = nfcmrvl_spi_nci_open, + .nci_close = nfcmrvl_spi_nci_close, + .nci_send = nfcmrvl_spi_nci_send, + .nci_update_config = nfcmrvl_spi_nci_update_config, +}; + +static int nfcmrvl_spi_parse_dt(struct device_node *node, + struct nfcmrvl_platform_data *pdata) +{ + int ret; + + ret = nfcmrvl_parse_dt(node, pdata); + if (ret < 0) { + pr_err("Failed to get generic entries\n"); + return ret; + } + + ret = irq_of_parse_and_map(node, 0); + if (!ret) { + pr_err("Unable to get irq\n"); + return -EINVAL; + } + pdata->irq = ret; + + return 0; +} + +static int nfcmrvl_spi_probe(struct spi_device *spi) +{ + const struct nfcmrvl_platform_data *pdata; + struct nfcmrvl_platform_data config; + struct nfcmrvl_spi_drv_data *drv_data; + int ret = 0; + + drv_data = devm_kzalloc(&spi->dev, sizeof(*drv_data), GFP_KERNEL); + if (!drv_data) + return -ENOMEM; + + drv_data->spi = spi; + drv_data->priv = NULL; + spi_set_drvdata(spi, drv_data); + + pdata = spi->dev.platform_data; + + if (!pdata && spi->dev.of_node) + if (nfcmrvl_spi_parse_dt(spi->dev.of_node, &config) == 0) + pdata = &config; + + if (!pdata) + return -EINVAL; + + ret = devm_request_threaded_irq(&drv_data->spi->dev, pdata->irq, + NULL, nfcmrvl_spi_int_irq_thread_fn, + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + "nfcmrvl_spi_int", drv_data); + if (ret < 0) { + nfc_err(&drv_data->spi->dev, "Unable to register IRQ handler"); + return -ENODEV; + } + + drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_SPI, + drv_data, &spi_ops, + &drv_data->spi->dev, + pdata); + if (IS_ERR(drv_data->priv)) + return PTR_ERR(drv_data->priv); + + drv_data->priv->support_fw_dnld = true; + + drv_data->nci_spi = nci_spi_allocate_spi(drv_data->spi, 0, 10, + drv_data->priv->ndev); + + /* Init completion for slave handshake */ + init_completion(&drv_data->handshake_completion); + return 0; +} + +static void nfcmrvl_spi_remove(struct spi_device *spi) +{ + struct nfcmrvl_spi_drv_data *drv_data = spi_get_drvdata(spi); + + nfcmrvl_nci_unregister_dev(drv_data->priv); +} + +static const struct of_device_id of_nfcmrvl_spi_match[] __maybe_unused = { + { .compatible = "marvell,nfc-spi", }, + {}, +}; +MODULE_DEVICE_TABLE(of, of_nfcmrvl_spi_match); + +static const struct spi_device_id nfcmrvl_spi_id_table[] = { + { "nfcmrvl_spi", 0 }, + { } +}; +MODULE_DEVICE_TABLE(spi, nfcmrvl_spi_id_table); + +static struct spi_driver nfcmrvl_spi_driver = { + .probe = nfcmrvl_spi_probe, + .remove = nfcmrvl_spi_remove, + .id_table = nfcmrvl_spi_id_table, + .driver = { + .name = "nfcmrvl_spi", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(of_nfcmrvl_spi_match), + }, +}; + +module_spi_driver(nfcmrvl_spi_driver); + +MODULE_AUTHOR("Marvell International Ltd."); +MODULE_DESCRIPTION("Marvell NFC-over-SPI driver"); +MODULE_LICENSE("GPL v2"); |