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
 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}