drivers/media/dvb-frontends/cxd2880/cxd2880_spi_device.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * cxd2880_spi_device.c
   4  * Sony CXD2880 DVB-T2/T tuner + demodulator driver
   5  * SPI access functions
   6  *
   7  * Copyright (C) 2016, 2017, 2018 Sony Semiconductor Solutions Corporation
   8  */
   9
  10 #include <linux/spi/spi.h>
  11
  12 #include "cxd2880_spi_device.h"
  13
  14 static int cxd2880_spi_device_write(struct cxd2880_spi *spi,
  15                                     const u8 *data, u32 size)
  16 {
  17         struct cxd2880_spi_device *spi_device = NULL;
  18         struct spi_message msg;
  19         struct spi_transfer tx;
  20         int result = 0;
  21
  22         if (!spi || !spi->user || !data || size == 0)
  23                 return -EINVAL;
  24
  25         spi_device = spi->user;
  26
  27         memset(&tx, 0, sizeof(tx));
  28         tx.tx_buf = data;
  29         tx.len = size;
  30
  31         spi_message_init(&msg);
  32         spi_message_add_tail(&tx, &msg);
  33         result = spi_sync(spi_device->spi, &msg);
  34
  35         if (result < 0)
  36                 return -EIO;
  37
  38         return 0;
  39 }
  40
  41 static int cxd2880_spi_device_write_read(struct cxd2880_spi *spi,
  42                                          const u8 *tx_data,
  43                                          u32 tx_size,
  44                                          u8 *rx_data,
  45                                          u32 rx_size)
  46 {
  47         struct cxd2880_spi_device *spi_device = NULL;
  48         int result = 0;
  49
  50         if (!spi || !spi->user || !tx_data ||
  51             !tx_size || !rx_data || !rx_size)
  52                 return -EINVAL;
  53
  54         spi_device = spi->user;
  55
  56         result = spi_write_then_read(spi_device->spi, tx_data,
  57                                      tx_size, rx_data, rx_size);
  58         if (result < 0)
  59                 return -EIO;
  60
  61         return 0;
  62 }
  63
  64 int
  65 cxd2880_spi_device_initialize(struct cxd2880_spi_device *spi_device,
  66                               enum cxd2880_spi_mode mode,
  67                               u32 speed_hz)
  68 {
  69         int result = 0;
  70         struct spi_device *spi = spi_device->spi;
  71
  72         switch (mode) {
  73         case CXD2880_SPI_MODE_0:
  74                 spi->mode = SPI_MODE_0;
  75                 break;
  76         case CXD2880_SPI_MODE_1:
  77                 spi->mode = SPI_MODE_1;
  78                 break;
  79         case CXD2880_SPI_MODE_2:
  80                 spi->mode = SPI_MODE_2;
  81                 break;
  82         case CXD2880_SPI_MODE_3:
  83                 spi->mode = SPI_MODE_3;
  84                 break;
  85         default:
  86                 return -EINVAL;
  87         }
  88
  89         spi->max_speed_hz = speed_hz;
  90         spi->bits_per_word = 8;
  91         result = spi_setup(spi);
  92         if (result != 0) {
  93                 pr_err("spi_setup failed %d\n", result);
  94                 return -EINVAL;
  95         }
  96
  97         return 0;
  98 }
  99
 100 int cxd2880_spi_device_create_spi(struct cxd2880_spi *spi,
 101                                   struct cxd2880_spi_device *spi_device)
 102 {
 103         if (!spi || !spi_device)
 104                 return -EINVAL;
 105
 106         spi->read = NULL;
 107         spi->write = cxd2880_spi_device_write;
 108         spi->write_read = cxd2880_spi_device_write_read;
 109         spi->flags = 0;
 110         spi->user = spi_device;
 111
 112         return 0;
 113 }