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 "nfcmrvl.h"
  30
  31 #define SPI_WAIT_HANDSHAKE      1
  32
  33 struct nfcmrvl_spi_drv_data {
  34         unsigned long flags;
  35         struct spi_device *spi;
  36         struct nci_spi *nci_spi;
  37         struct completion handshake_completion;
  38         struct nfcmrvl_private *priv;
  39 };
  40
  41 static irqreturn_t nfcmrvl_spi_int_irq_thread_fn(int irq, void *drv_data_ptr)
  42 {
  43         struct nfcmrvl_spi_drv_data *drv_data = drv_data_ptr;
  44         struct sk_buff *skb;
  45
  46         /*
  47          * Special case where we are waiting for SPI_INT deassertion to start a
  48          * transfer.
  49          */
  50         if (test_and_clear_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags)) {
  51                 complete(&drv_data->handshake_completion);
  52                 return IRQ_HANDLED;
  53         }
  54
  55         /* Normal case, SPI_INT deasserted by slave to trigger a master read */
  56
  57         skb = nci_spi_read(drv_data->nci_spi);
  58         if (!skb) {
  59                 nfc_err(&drv_data->spi->dev, "failed to read spi packet");
  60                 return IRQ_HANDLED;
  61         }
  62
  63         if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0)
  64                 nfc_err(&drv_data->spi->dev, "corrupted RX packet");
  65
  66         return IRQ_HANDLED;
  67 }
  68
  69 static int nfcmrvl_spi_nci_open(struct nfcmrvl_private *priv)
  70 {
  71         return 0;
  72 }
  73
  74 static int nfcmrvl_spi_nci_close(struct nfcmrvl_private *priv)
  75 {
  76         return 0;
  77 }
  78
  79 static int nfcmrvl_spi_nci_send(struct nfcmrvl_private *priv,
  80                                 struct sk_buff *skb)
  81 {
  82         struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data;
  83         int err;
  84
  85         /* Reinit completion for slave handshake */
  86         reinit_completion(&drv_data->handshake_completion);
  87         set_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags);
  88
  89         /*
  90          * Append a dummy byte at the end of SPI frame. This is due to a
  91          * specific DMA implementation in the controller
  92          */
  93         skb_put(skb, 1);
  94
  95         /* Send the SPI packet */
  96         err = nci_spi_send(drv_data->nci_spi, &drv_data->handshake_completion,
  97                            skb);
  98         if (err)
  99                 nfc_err(priv->dev, "spi_send failed %d", err);
 100
 101         return err;
 102 }
 103
 104 static void nfcmrvl_spi_nci_update_config(struct nfcmrvl_private *priv,
 105                                           const void *param)
 106 {
 107         struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data;
 108         const struct nfcmrvl_fw_spi_config *config = param;
 109
 110         drv_data->nci_spi->xfer_speed_hz = config->clk;
 111 }
 112
 113 static struct nfcmrvl_if_ops spi_ops = {
 114         .nci_open = nfcmrvl_spi_nci_open,
 115         .nci_close = nfcmrvl_spi_nci_close,
 116         .nci_send = nfcmrvl_spi_nci_send,
 117         .nci_update_config = nfcmrvl_spi_nci_update_config,
 118 };
 119
 120 static int nfcmrvl_spi_parse_dt(struct device_node *node,
 121                                 struct nfcmrvl_platform_data *pdata)
 122 {
 123         int ret;
 124
 125         ret = nfcmrvl_parse_dt(node, pdata);
 126         if (ret < 0) {
 127                 pr_err("Failed to get generic entries\n");
 128                 return ret;
 129         }
 130
 131         ret = irq_of_parse_and_map(node, 0);
 132         if (ret < 0) {
 133                 pr_err("Unable to get irq, error: %d\n", ret);
 134                 return ret;
 135         }
 136         pdata->irq = ret;
 137
 138         return 0;
 139 }
 140
 141 static int nfcmrvl_spi_probe(struct spi_device *spi)
 142 {
 143         struct nfcmrvl_platform_data *pdata;
 144         struct nfcmrvl_platform_data config;
 145         struct nfcmrvl_spi_drv_data *drv_data;
 146         int ret = 0;
 147
 148         drv_data = devm_kzalloc(&spi->dev, sizeof(*drv_data), GFP_KERNEL);
 149         if (!drv_data)
 150                 return -ENOMEM;
 151
 152         drv_data->spi = spi;
 153         drv_data->priv = NULL;
 154         spi_set_drvdata(spi, drv_data);
 155
 156         pdata = spi->dev.platform_data;
 157
 158         if (!pdata && spi->dev.of_node)
 159                 if (nfcmrvl_spi_parse_dt(spi->dev.of_node, &config) == 0)
 160                         pdata = &config;
 161
 162         if (!pdata)
 163                 return -EINVAL;
 164
 165         ret = devm_request_threaded_irq(&drv_data->spi->dev, pdata->irq,
 166                                         NULL, nfcmrvl_spi_int_irq_thread_fn,
 167                                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 168                                         "nfcmrvl_spi_int", drv_data);
 169         if (ret < 0) {
 170                 nfc_err(&drv_data->spi->dev, "Unable to register IRQ handler");
 171                 return -ENODEV;
 172         }
 173
 174         drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_SPI,
 175                                                   drv_data, &spi_ops,
 176                                                   &drv_data->spi->dev,
 177                                                   pdata);
 178         if (IS_ERR(drv_data->priv))
 179                 return PTR_ERR(drv_data->priv);
 180
 181         drv_data->priv->support_fw_dnld = true;
 182
 183         drv_data->nci_spi = nci_spi_allocate_spi(drv_data->spi, 0, 10,
 184                                                  drv_data->priv->ndev);
 185
 186         /* Init completion for slave handshake */
 187         init_completion(&drv_data->handshake_completion);
 188         return 0;
 189 }
 190
 191 static int nfcmrvl_spi_remove(struct spi_device *spi)
 192 {
 193         struct nfcmrvl_spi_drv_data *drv_data = spi_get_drvdata(spi);
 194
 195         nfcmrvl_nci_unregister_dev(drv_data->priv);
 196         return 0;
 197 }
 198
 199 static const struct of_device_id of_nfcmrvl_spi_match[] = {
 200         { .compatible = "marvell,nfc-spi", },
 201         {},
 202 };
 203 MODULE_DEVICE_TABLE(of, of_nfcmrvl_spi_match);
 204
 205 static const struct spi_device_id nfcmrvl_spi_id_table[] = {
 206         { "nfcmrvl_spi", 0 },
 207         { }
 208 };
 209 MODULE_DEVICE_TABLE(spi, nfcmrvl_spi_id_table);
 210
 211 static struct spi_driver nfcmrvl_spi_driver = {
 212         .probe          = nfcmrvl_spi_probe,
 213         .remove         = nfcmrvl_spi_remove,
 214         .id_table       = nfcmrvl_spi_id_table,
 215         .driver         = {
 216                 .name           = "nfcmrvl_spi",
 217                 .owner          = THIS_MODULE,
 218                 .of_match_table = of_match_ptr(of_nfcmrvl_spi_match),
 219         },
 220 };
 221
 222 module_spi_driver(nfcmrvl_spi_driver);
 223
 224 MODULE_AUTHOR("Marvell International Ltd.");
 225 MODULE_DESCRIPTION("Marvell NFC-over-SPI driver");
 226 MODULE_LICENSE("GPL v2");