drivers/net/ethernet/qualcomm/qca_7k.c

   1 /*
   2  *
   3  *   Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
   4  *   Copyright (c) 2014, I2SE GmbH
   5  *
   6  *   Permission to use, copy, modify, and/or distribute this software
   7  *   for any purpose with or without fee is hereby granted, provided
   8  *   that the above copyright notice and this permission notice appear
   9  *   in all copies.
  10  *
  11  *   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
  12  *   WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
  13  *   WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
  14  *   THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
  15  *   CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  16  *   LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
  17  *   NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  18  *   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  19  *
  20  */
  21
  22 /*   This module implements the Qualcomm Atheros SPI protocol for
  23  *   kernel-based SPI device.
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/spi/spi.h>
  29
  30 #include "qca_7k.h"
  31
  32 void
  33 qcaspi_spi_error(struct qcaspi *qca)
  34 {
  35         if (qca->sync != QCASPI_SYNC_READY)
  36                 return;
  37
  38         netdev_err(qca->net_dev, "spi error\n");
  39         qca->sync = QCASPI_SYNC_UNKNOWN;
  40         qca->stats.spi_err++;
  41 }
  42
  43 int
  44 qcaspi_read_register(struct qcaspi *qca, u16 reg, u16 *result)
  45 {
  46         __be16 rx_data;
  47         __be16 tx_data;
  48         struct spi_transfer *transfer;
  49         struct spi_message *msg;
  50         int ret;
  51
  52         tx_data = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_INTERNAL | reg);
  53
  54         if (qca->legacy_mode) {
  55                 msg = &qca->spi_msg1;
  56                 transfer = &qca->spi_xfer1;
  57                 transfer->tx_buf = &tx_data;
  58                 transfer->rx_buf = NULL;
  59                 transfer->len = QCASPI_CMD_LEN;
  60                 spi_sync(qca->spi_dev, msg);
  61         } else {
  62                 msg = &qca->spi_msg2;
  63                 transfer = &qca->spi_xfer2[0];
  64                 transfer->tx_buf = &tx_data;
  65                 transfer->rx_buf = NULL;
  66                 transfer->len = QCASPI_CMD_LEN;
  67                 transfer = &qca->spi_xfer2[1];
  68         }
  69         transfer->tx_buf = NULL;
  70         transfer->rx_buf = &rx_data;
  71         transfer->len = QCASPI_CMD_LEN;
  72         ret = spi_sync(qca->spi_dev, msg);
  73
  74         if (!ret)
  75                 ret = msg->status;
  76
  77         if (ret)
  78                 qcaspi_spi_error(qca);
  79         else
  80                 *result = be16_to_cpu(rx_data);
  81
  82         return ret;
  83 }
  84
  85 int
  86 qcaspi_write_register(struct qcaspi *qca, u16 reg, u16 value)
  87 {
  88         __be16 tx_data[2];
  89         struct spi_transfer *transfer;
  90         struct spi_message *msg;
  91         int ret;
  92
  93         tx_data[0] = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_INTERNAL | reg);
  94         tx_data[1] = cpu_to_be16(value);
  95
  96         if (qca->legacy_mode) {
  97                 msg = &qca->spi_msg1;
  98                 transfer = &qca->spi_xfer1;
  99                 transfer->tx_buf = &tx_data[0];
 100                 transfer->rx_buf = NULL;
 101                 transfer->len = QCASPI_CMD_LEN;
 102                 spi_sync(qca->spi_dev, msg);
 103         } else {
 104                 msg = &qca->spi_msg2;
 105                 transfer = &qca->spi_xfer2[0];
 106                 transfer->tx_buf = &tx_data[0];
 107                 transfer->rx_buf = NULL;
 108                 transfer->len = QCASPI_CMD_LEN;
 109                 transfer = &qca->spi_xfer2[1];
 110         }
 111         transfer->tx_buf = &tx_data[1];
 112         transfer->rx_buf = NULL;
 113         transfer->len = QCASPI_CMD_LEN;
 114         ret = spi_sync(qca->spi_dev, msg);
 115
 116         if (!ret)
 117                 ret = msg->status;
 118
 119         if (ret)
 120                 qcaspi_spi_error(qca);
 121
 122         return ret;
 123 }