drivers/net/ethernet/asix/ax88796c_spi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2010 ASIX Electronics Corporation
   4  * Copyright (c) 2020 Samsung Electronics Co., Ltd.
   5  *
   6  * ASIX AX88796C SPI Fast Ethernet Linux driver
   7  */
   8
   9 #define pr_fmt(fmt)     "ax88796c: " fmt
  10
  11 #include <linux/string.h>
  12 #include <linux/spi/spi.h>
  13
  14 #include "ax88796c_spi.h"
  15
  16 const u8 ax88796c_rx_cmd_buf[5] = {AX_SPICMD_READ_RXQ, 0xFF, 0xFF, 0xFF, 0xFF};
  17 const u8 ax88796c_tx_cmd_buf[4] = {AX_SPICMD_WRITE_TXQ, 0xFF, 0xFF, 0xFF};
  18
  19 /* driver bus management functions */
  20 int axspi_wakeup(struct axspi_data *ax_spi)
  21 {
  22         int ret;
  23
  24         ax_spi->cmd_buf[0] = AX_SPICMD_EXIT_PWD;        /* OP */
  25         ret = spi_write(ax_spi->spi, ax_spi->cmd_buf, 1);
  26         if (ret)
  27                 dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
  28         return ret;
  29 }
  30
  31 int axspi_read_status(struct axspi_data *ax_spi, struct spi_status *status)
  32 {
  33         int ret;
  34
  35         /* OP */
  36         ax_spi->cmd_buf[0] = AX_SPICMD_READ_STATUS;
  37         ret = spi_write_then_read(ax_spi->spi, ax_spi->cmd_buf, 1, (u8 *)status, 3);
  38         if (ret)
  39                 dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
  40         else
  41                 le16_to_cpus(&status->isr);
  42
  43         return ret;
  44 }
  45
  46 int axspi_read_rxq(struct axspi_data *ax_spi, void *data, int len)
  47 {
  48         struct spi_transfer *xfer = ax_spi->spi_rx_xfer;
  49         int ret;
  50
  51         memcpy(ax_spi->cmd_buf, ax88796c_rx_cmd_buf, 5);
  52
  53         xfer->tx_buf = ax_spi->cmd_buf;
  54         xfer->rx_buf = NULL;
  55         xfer->len = ax_spi->comp ? 2 : 5;
  56         xfer->bits_per_word = 8;
  57         spi_message_add_tail(xfer, &ax_spi->rx_msg);
  58
  59         xfer++;
  60         xfer->rx_buf = data;
  61         xfer->tx_buf = NULL;
  62         xfer->len = len;
  63         xfer->bits_per_word = 8;
  64         spi_message_add_tail(xfer, &ax_spi->rx_msg);
  65         ret = spi_sync(ax_spi->spi, &ax_spi->rx_msg);
  66         if (ret)
  67                 dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
  68
  69         return ret;
  70 }
  71
  72 int axspi_write_txq(const struct axspi_data *ax_spi, void *data, int len)
  73 {
  74         return spi_write(ax_spi->spi, data, len);
  75 }
  76
  77 u16 axspi_read_reg(struct axspi_data *ax_spi, u8 reg)
  78 {
  79         int ret;
  80         int len = ax_spi->comp ? 3 : 4;
  81
  82         ax_spi->cmd_buf[0] = 0x03;      /* OP code read register */
  83         ax_spi->cmd_buf[1] = reg;       /* register address */
  84         ax_spi->cmd_buf[2] = 0xFF;      /* dumy cycle */
  85         ax_spi->cmd_buf[3] = 0xFF;      /* dumy cycle */
  86         ret = spi_write_then_read(ax_spi->spi,
  87                                   ax_spi->cmd_buf, len,
  88                                   ax_spi->rx_buf, 2);
  89         if (ret) {
  90                 dev_err(&ax_spi->spi->dev,
  91                         "%s() failed: ret = %d\n", __func__, ret);
  92                 return 0xFFFF;
  93         }
  94
  95         le16_to_cpus((u16 *)ax_spi->rx_buf);
  96
  97         return *(u16 *)ax_spi->rx_buf;
  98 }
  99
 100 int axspi_write_reg(struct axspi_data *ax_spi, u8 reg, u16 value)
 101 {
 102         int ret;
 103
 104         memset(ax_spi->cmd_buf, 0, sizeof(ax_spi->cmd_buf));
 105         ax_spi->cmd_buf[0] = AX_SPICMD_WRITE_REG;       /* OP code read register */
 106         ax_spi->cmd_buf[1] = reg;                       /* register address */
 107         ax_spi->cmd_buf[2] = value;
 108         ax_spi->cmd_buf[3] = value >> 8;
 109
 110         ret = spi_write(ax_spi->spi, ax_spi->cmd_buf, 4);
 111         if (ret)
 112                 dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
 113         return ret;
 114 }
 115