drivers/nfc/nfcmrvl/spi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Marvell NFC-over-SPI driver: SPI interface related functions
   4  *
   5  * Copyright (C) 2015, Marvell International Ltd.
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/nfc.h>
  11 #include <linux/of_irq.h>
  12 #include <net/nfc/nci.h>
  13 #include <net/nfc/nci_core.h>
  14 #include <linux/spi/spi.h>
  15 #include "nfcmrvl.h"
  16
  17 #define SPI_WAIT_HANDSHAKE      1
  18
  19 struct nfcmrvl_spi_drv_data {
  20         unsigned long flags;
  21         struct spi_device *spi;
  22         struct nci_spi *nci_spi;
  23         struct completion handshake_completion;
  24         struct nfcmrvl_private *priv;
  25 };
  26
  27 static irqreturn_t nfcmrvl_spi_int_irq_thread_fn(int irq, void *drv_data_ptr)
  28 {
  29         struct nfcmrvl_spi_drv_data *drv_data = drv_data_ptr;
  30         struct sk_buff *skb;
  31
  32         /*
  33          * Special case where we are waiting for SPI_INT deassertion to start a
  34          * transfer.
  35          */
  36         if (test_and_clear_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags)) {
  37                 complete(&drv_data->handshake_completion);
  38                 return IRQ_HANDLED;
  39         }
  40
  41         /* Normal case, SPI_INT deasserted by slave to trigger a master read */
  42
  43         skb = nci_spi_read(drv_data->nci_spi);
  44         if (!skb) {
  45                 nfc_err(&drv_data->spi->dev, "failed to read spi packet");
  46                 return IRQ_HANDLED;
  47         }
  48
  49         if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0)
  50                 nfc_err(&drv_data->spi->dev, "corrupted RX packet");
  51
  52         return IRQ_HANDLED;
  53 }
  54
  55 static int nfcmrvl_spi_nci_open(struct nfcmrvl_private *priv)
  56 {
  57         return 0;
  58 }
  59
  60 static int nfcmrvl_spi_nci_close(struct nfcmrvl_private *priv)
  61 {
  62         return 0;
  63 }
  64
  65 static int nfcmrvl_spi_nci_send(struct nfcmrvl_private *priv,
  66                                 struct sk_buff *skb)
  67 {
  68         struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data;
  69         int err;
  70
  71         /* Reinit completion for slave handshake */
  72         reinit_completion(&drv_data->handshake_completion);
  73         set_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags);
  74
  75         /*
  76          * Append a dummy byte at the end of SPI frame. This is due to a
  77          * specific DMA implementation in the controller
  78          */
  79         skb_put(skb, 1);
  80
  81         /* Send the SPI packet */
  82         err = nci_spi_send(drv_data->nci_spi, &drv_data->handshake_completion,
  83                            skb);
  84         if (err)
  85                 nfc_err(priv->dev, "spi_send failed %d", err);
  86
  87         return err;
  88 }
  89
  90 static void nfcmrvl_spi_nci_update_config(struct nfcmrvl_private *priv,
  91                                           const void *param)
  92 {
  93         struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data;
  94         const struct nfcmrvl_fw_spi_config *config = param;
  95
  96         drv_data->nci_spi->xfer_speed_hz = config->clk;
  97 }
  98
  99 static const struct nfcmrvl_if_ops spi_ops = {
 100         .nci_open = nfcmrvl_spi_nci_open,
 101         .nci_close = nfcmrvl_spi_nci_close,
 102         .nci_send = nfcmrvl_spi_nci_send,
 103         .nci_update_config = nfcmrvl_spi_nci_update_config,
 104 };
 105
 106 static int nfcmrvl_spi_parse_dt(struct device_node *node,
 107                                 struct nfcmrvl_platform_data *pdata)
 108 {
 109         int ret;
 110
 111         ret = nfcmrvl_parse_dt(node, pdata);
 112         if (ret < 0) {
 113                 pr_err("Failed to get generic entries\n");
 114                 return ret;
 115         }
 116
 117         ret = irq_of_parse_and_map(node, 0);
 118         if (!ret) {
 119                 pr_err("Unable to get irq\n");
 120                 return -EINVAL;
 121         }
 122         pdata->irq = ret;
 123
 124         return 0;
 125 }
 126
 127 static int nfcmrvl_spi_probe(struct spi_device *spi)
 128 {
 129         const struct nfcmrvl_platform_data *pdata;
 130         struct nfcmrvl_platform_data config;
 131         struct nfcmrvl_spi_drv_data *drv_data;
 132         int ret = 0;
 133
 134         drv_data = devm_kzalloc(&spi->dev, sizeof(*drv_data), GFP_KERNEL);
 135         if (!drv_data)
 136                 return -ENOMEM;
 137
 138         drv_data->spi = spi;
 139         drv_data->priv = NULL;
 140         spi_set_drvdata(spi, drv_data);
 141
 142         pdata = spi->dev.platform_data;
 143
 144         if (!pdata && spi->dev.of_node)
 145                 if (nfcmrvl_spi_parse_dt(spi->dev.of_node, &config) == 0)
 146                         pdata = &config;
 147
 148         if (!pdata)
 149                 return -EINVAL;
 150
 151         ret = devm_request_threaded_irq(&drv_data->spi->dev, pdata->irq,
 152                                         NULL, nfcmrvl_spi_int_irq_thread_fn,
 153                                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 154                                         "nfcmrvl_spi_int", drv_data);
 155         if (ret < 0) {
 156                 nfc_err(&drv_data->spi->dev, "Unable to register IRQ handler");
 157                 return -ENODEV;
 158         }
 159
 160         drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_SPI,
 161                                                   drv_data, &spi_ops,
 162                                                   &drv_data->spi->dev,
 163                                                   pdata);
 164         if (IS_ERR(drv_data->priv))
 165                 return PTR_ERR(drv_data->priv);
 166
 167         drv_data->priv->support_fw_dnld = true;
 168
 169         drv_data->nci_spi = nci_spi_allocate_spi(drv_data->spi, 0, 10,
 170                                                  drv_data->priv->ndev);
 171
 172         /* Init completion for slave handshake */
 173         init_completion(&drv_data->handshake_completion);
 174         return 0;
 175 }
 176
 177 static void nfcmrvl_spi_remove(struct spi_device *spi)
 178 {
 179         struct nfcmrvl_spi_drv_data *drv_data = spi_get_drvdata(spi);
 180
 181         nfcmrvl_nci_unregister_dev(drv_data->priv);
 182 }
 183
 184 static const struct of_device_id of_nfcmrvl_spi_match[] __maybe_unused = {
 185         { .compatible = "marvell,nfc-spi", },
 186         {},
 187 };
 188 MODULE_DEVICE_TABLE(of, of_nfcmrvl_spi_match);
 189
 190 static const struct spi_device_id nfcmrvl_spi_id_table[] = {
 191         { "nfcmrvl_spi", 0 },
 192         { }
 193 };
 194 MODULE_DEVICE_TABLE(spi, nfcmrvl_spi_id_table);
 195
 196 static struct spi_driver nfcmrvl_spi_driver = {
 197         .probe          = nfcmrvl_spi_probe,
 198         .remove         = nfcmrvl_spi_remove,
 199         .id_table       = nfcmrvl_spi_id_table,
 200         .driver         = {
 201                 .name           = "nfcmrvl_spi",
 202                 .of_match_table = of_match_ptr(of_nfcmrvl_spi_match),
 203         },
 204 };
 205
 206 module_spi_driver(nfcmrvl_spi_driver);
 207
 208 MODULE_AUTHOR("Marvell International Ltd.");
 209 MODULE_DESCRIPTION("Marvell NFC-over-SPI driver");
 210 MODULE_LICENSE("GPL v2");