cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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cxd2880_spi_device.c (2266B)

      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
     14static 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
     41static 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
     64int
     65cxd2880_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
    100int 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}