drivers/nfc/nfcmrvl/spi.c

   1 /**
   2  * Marvell NFC-over-SPI driver: SPI interface related functions
   3  *
   4  * Copyright (C) 2015, Marvell International Ltd.
   5  *
   6  * This software file (the "File") is distributed by Marvell International
   7  * Ltd. under the terms of the GNU General Public License Version 2, June 1991
   8  * (the "License").  You may use, redistribute and/or modify this File in
   9  * accordance with the terms and conditions of the License, a copy of which
  10  * is available on the worldwide web at
  11  * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
  12  *
  13  * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
  14  * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
  15  * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
  16  * this warranty disclaimer.
  17  **/
  18
  19 #include <linux/module.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/pm_runtime.h>
  22 #include <linux/nfc.h>
  23 #include <linux/gpio.h>
  24 #include <linux/of_irq.h>
  25 #include <linux/of_gpio.h>
  26 #include <net/nfc/nci.h>
  27 #include <net/nfc/nci_core.h>
  28 #include <linux/spi/spi.h>
  29 #include <linux/gpio.h>
  30 #include "nfcmrvl.h"
  31
  32 #define SPI_WAIT_HANDSHAKE      1
  33
  34 struct nfcmrvl_spi_drv_data {
  35         unsigned long flags;
  36         struct spi_device *spi;
  37         struct nci_spi *nci_spi;
  38         struct completion handshake_completion;
  39         struct nfcmrvl_private *priv;
  40 };
  41
  42 static irqreturn_t nfcmrvl_spi_int_irq_thread_fn(int irq, void *drv_data_ptr)
  43 {
  44         struct nfcmrvl_spi_drv_data *drv_data = drv_data_ptr;
  45         struct sk_buff *skb;
  46
  47         /*
  48          * Special case where we are waiting for SPI_INT deassertion to start a
  49          * transfer.
  50          */
  51         if (test_and_clear_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags)) {
  52                 complete(&drv_data->handshake_completion);
  53                 return IRQ_HANDLED;
  54         }
  55
  56         /* Normal case, SPI_INT deasserted by slave to trigger a master read */
  57
  58         skb = nci_spi_read(drv_data->nci_spi);
  59         if (!skb) {
  60                 nfc_err(&drv_data->spi->dev, "failed to read spi packet");
  61                 return IRQ_HANDLED;
  62         }
  63
  64         if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0)
  65                 nfc_err(&drv_data->spi->dev, "corrupted RX packet");
  66
  67         return IRQ_HANDLED;
  68 }
  69
  70 static int nfcmrvl_spi_nci_open(struct nfcmrvl_private *priv)
  71 {
  72         return 0;
  73 }
  74
  75 static int nfcmrvl_spi_nci_close(struct nfcmrvl_private *priv)
  76 {
  77         return 0;
  78 }
  79
  80 static int nfcmrvl_spi_nci_send(struct nfcmrvl_private *priv,
  81                                 struct sk_buff *skb)
  82 {
  83         struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data;
  84         int err;
  85
  86         /* Reinit completion for slave handshake */
  87         reinit_completion(&drv_data->handshake_completion);
  88         set_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags);
  89
  90         /*
  91          * Append a dummy byte at the end of SPI frame. This is due to a
  92          * specific DMA implementation in the controller
  93          */
  94         skb_put(skb, 1);
  95
  96         /* Send the SPI packet */
  97         err = nci_spi_send(drv_data->nci_spi, &drv_data->handshake_completion,
  98                            skb);
  99         if (err != 0) {
 100                 nfc_err(priv->dev, "spi_send failed %d", err);
 101                 kfree_skb(skb);
 102         }
 103         return err;
 104 }
 105
 106 static void nfcmrvl_spi_nci_update_config(struct nfcmrvl_private *priv,
 107                                           const void *param)
 108 {
 109         struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data;
 110         const struct nfcmrvl_fw_spi_config *config = param;
 111
 112         drv_data->nci_spi->xfer_speed_hz = config->clk;
 113 }
 114
 115 static struct nfcmrvl_if_ops spi_ops = {
 116         .nci_open = nfcmrvl_spi_nci_open,
 117         .nci_close = nfcmrvl_spi_nci_close,
 118         .nci_send = nfcmrvl_spi_nci_send,
 119         .nci_update_config = nfcmrvl_spi_nci_update_config,
 120 };
 121
 122 static int nfcmrvl_spi_parse_dt(struct device_node *node,
 123                                 struct nfcmrvl_platform_data *pdata)
 124 {
 125         int ret;
 126
 127         ret = nfcmrvl_parse_dt(node, pdata);
 128         if (ret < 0) {
 129                 pr_err("Failed to get generic entries\n");
 130                 return ret;
 131         }
 132
 133         ret = irq_of_parse_and_map(node, 0);
 134         if (ret < 0) {
 135                 pr_err("Unable to get irq, error: %d\n", ret);
 136                 return ret;
 137         }
 138         pdata->irq = ret;
 139
 140         return 0;
 141 }
 142
 143 static int nfcmrvl_spi_probe(struct spi_device *spi)
 144 {
 145         struct nfcmrvl_platform_data *pdata;
 146         struct nfcmrvl_platform_data config;
 147         struct nfcmrvl_spi_drv_data *drv_data;
 148         int ret = 0;
 149
 150         drv_data = devm_kzalloc(&spi->dev, sizeof(*drv_data), GFP_KERNEL);
 151         if (!drv_data)
 152                 return -ENOMEM;
 153
 154         drv_data->spi = spi;
 155         drv_data->priv = NULL;
 156         spi_set_drvdata(spi, drv_data);
 157
 158         pdata = spi->dev.platform_data;
 159
 160         if (!pdata && spi->dev.of_node)
 161                 if (nfcmrvl_spi_parse_dt(spi->dev.of_node, &config) == 0)
 162                         pdata = &config;
 163
 164         if (!pdata)
 165                 return -EINVAL;
 166
 167         ret = devm_request_threaded_irq(&drv_data->spi->dev, pdata->irq,
 168                                         NULL, nfcmrvl_spi_int_irq_thread_fn,
 169                                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 170                                         "nfcmrvl_spi_int", drv_data);
 171         if (ret < 0) {
 172                 nfc_err(&drv_data->spi->dev, "Unable to register IRQ handler");
 173                 return -ENODEV;
 174         }
 175
 176         drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_SPI,
 177                                                   drv_data, &spi_ops,
 178                                                   &drv_data->spi->dev,
 179                                                   pdata);
 180         if (IS_ERR(drv_data->priv))
 181                 return PTR_ERR(drv_data->priv);
 182
 183         drv_data->priv->support_fw_dnld = true;
 184
 185         drv_data->nci_spi = nci_spi_allocate_spi(drv_data->spi, 0, 10,
 186                                                  drv_data->priv->ndev);
 187
 188         /* Init completion for slave handshake */
 189         init_completion(&drv_data->handshake_completion);
 190         return 0;
 191 }
 192
 193 static int nfcmrvl_spi_remove(struct spi_device *spi)
 194 {
 195         struct nfcmrvl_spi_drv_data *drv_data = spi_get_drvdata(spi);
 196
 197         nfcmrvl_nci_unregister_dev(drv_data->priv);
 198         return 0;
 199 }
 200
 201 static const struct of_device_id of_nfcmrvl_spi_match[] = {
 202         { .compatible = "marvell,nfc-spi", },
 203         {},
 204 };
 205 MODULE_DEVICE_TABLE(of, of_nfcmrvl_spi_match);
 206
 207 static const struct spi_device_id nfcmrvl_spi_id_table[] = {
 208         { "nfcmrvl_spi", 0 },
 209         { }
 210 };
 211 MODULE_DEVICE_TABLE(spi, nfcmrvl_spi_id_table);
 212
 213 static struct spi_driver nfcmrvl_spi_driver = {
 214         .probe          = nfcmrvl_spi_probe,
 215         .remove         = nfcmrvl_spi_remove,
 216         .id_table       = nfcmrvl_spi_id_table,
 217         .driver         = {
 218                 .name           = "nfcmrvl_spi",
 219                 .owner          = THIS_MODULE,
 220                 .of_match_table = of_match_ptr(of_nfcmrvl_spi_match),
 221         },
 222 };
 223
 224 module_spi_driver(nfcmrvl_spi_driver);
 225
 226 MODULE_AUTHOR("Marvell International Ltd.");
 227 MODULE_DESCRIPTION("Marvell NFC-over-SPI driver");
 228 MODULE_LICENSE("GPL v2");