// SPDX-License-Identifier: GPL-2.0
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/*
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* Greybus SPI library
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*
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* Copyright 2014-2016 Google Inc.
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* Copyright 2014-2016 Linaro Ltd.
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*/
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#include <linux/bitops.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/greybus.h>
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#include <linux/spi/spi.h>
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#include "spilib.h"
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struct gb_spilib {
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struct gb_connection *connection;
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struct device *parent;
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struct spi_transfer *first_xfer;
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struct spi_transfer *last_xfer;
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struct spilib_ops *ops;
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u32 rx_xfer_offset;
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u32 tx_xfer_offset;
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u32 last_xfer_size;
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unsigned int op_timeout;
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u16 mode;
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u16 flags;
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u32 bits_per_word_mask;
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u8 num_chipselect;
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u32 min_speed_hz;
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u32 max_speed_hz;
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};
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#define GB_SPI_STATE_MSG_DONE ((void *)0)
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#define GB_SPI_STATE_MSG_IDLE ((void *)1)
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#define GB_SPI_STATE_MSG_RUNNING ((void *)2)
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#define GB_SPI_STATE_OP_READY ((void *)3)
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#define GB_SPI_STATE_OP_DONE ((void *)4)
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#define GB_SPI_STATE_MSG_ERROR ((void *)-1)
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#define XFER_TIMEOUT_TOLERANCE 200
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static struct spi_master *get_master_from_spi(struct gb_spilib *spi)
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{
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return gb_connection_get_data(spi->connection);
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}
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static int tx_header_fit_operation(u32 tx_size, u32 count, size_t data_max)
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{
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size_t headers_size;
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data_max -= sizeof(struct gb_spi_transfer_request);
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headers_size = (count + 1) * sizeof(struct gb_spi_transfer);
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return tx_size + headers_size > data_max ? 0 : 1;
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}
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static size_t calc_rx_xfer_size(u32 rx_size, u32 *tx_xfer_size, u32 len,
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size_t data_max)
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{
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size_t rx_xfer_size;
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data_max -= sizeof(struct gb_spi_transfer_response);
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if (rx_size + len > data_max)
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rx_xfer_size = data_max - rx_size;
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else
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rx_xfer_size = len;
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/* if this is a write_read, for symmetry read the same as write */
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if (*tx_xfer_size && rx_xfer_size > *tx_xfer_size)
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rx_xfer_size = *tx_xfer_size;
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if (*tx_xfer_size && rx_xfer_size < *tx_xfer_size)
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*tx_xfer_size = rx_xfer_size;
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return rx_xfer_size;
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}
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static size_t calc_tx_xfer_size(u32 tx_size, u32 count, size_t len,
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size_t data_max)
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{
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size_t headers_size;
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data_max -= sizeof(struct gb_spi_transfer_request);
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headers_size = (count + 1) * sizeof(struct gb_spi_transfer);
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if (tx_size + headers_size + len > data_max)
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return data_max - (tx_size + sizeof(struct gb_spi_transfer));
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return len;
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}
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static void clean_xfer_state(struct gb_spilib *spi)
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{
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spi->first_xfer = NULL;
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spi->last_xfer = NULL;
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spi->rx_xfer_offset = 0;
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spi->tx_xfer_offset = 0;
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spi->last_xfer_size = 0;
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spi->op_timeout = 0;
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}
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static bool is_last_xfer_done(struct gb_spilib *spi)
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{
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struct spi_transfer *last_xfer = spi->last_xfer;
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if ((spi->tx_xfer_offset + spi->last_xfer_size == last_xfer->len) ||
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(spi->rx_xfer_offset + spi->last_xfer_size == last_xfer->len))
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return true;
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return false;
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}
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static int setup_next_xfer(struct gb_spilib *spi, struct spi_message *msg)
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{
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struct spi_transfer *last_xfer = spi->last_xfer;
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if (msg->state != GB_SPI_STATE_OP_DONE)
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return 0;
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/*
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* if we transferred all content of the last transfer, reset values and
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* check if this was the last transfer in the message
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*/
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if (is_last_xfer_done(spi)) {
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spi->tx_xfer_offset = 0;
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spi->rx_xfer_offset = 0;
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spi->op_timeout = 0;
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if (last_xfer == list_last_entry(&msg->transfers,
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struct spi_transfer,
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transfer_list))
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msg->state = GB_SPI_STATE_MSG_DONE;
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else
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spi->first_xfer = list_next_entry(last_xfer,
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transfer_list);
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return 0;
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}
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spi->first_xfer = last_xfer;
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if (last_xfer->tx_buf)
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spi->tx_xfer_offset += spi->last_xfer_size;
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if (last_xfer->rx_buf)
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spi->rx_xfer_offset += spi->last_xfer_size;
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return 0;
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}
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static struct spi_transfer *get_next_xfer(struct spi_transfer *xfer,
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struct spi_message *msg)
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{
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if (xfer == list_last_entry(&msg->transfers, struct spi_transfer,
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transfer_list))
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return NULL;
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return list_next_entry(xfer, transfer_list);
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}
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/* Routines to transfer data */
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static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,
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struct gb_connection *connection, struct spi_message *msg)
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{
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struct gb_spi_transfer_request *request;
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struct spi_device *dev = msg->spi;
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struct spi_transfer *xfer;
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struct gb_spi_transfer *gb_xfer;
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struct gb_operation *operation;
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u32 tx_size = 0, rx_size = 0, count = 0, xfer_len = 0, request_size;
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u32 tx_xfer_size = 0, rx_xfer_size = 0, len;
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u32 total_len = 0;
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unsigned int xfer_timeout;
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size_t data_max;
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void *tx_data;
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data_max = gb_operation_get_payload_size_max(connection);
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xfer = spi->first_xfer;
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/* Find number of transfers queued and tx/rx length in the message */
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while (msg->state != GB_SPI_STATE_OP_READY) {
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msg->state = GB_SPI_STATE_MSG_RUNNING;
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spi->last_xfer = xfer;
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if (!xfer->tx_buf && !xfer->rx_buf) {
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dev_err(spi->parent,
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"bufferless transfer, length %u\n", xfer->len);
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msg->state = GB_SPI_STATE_MSG_ERROR;
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return NULL;
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}
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tx_xfer_size = 0;
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rx_xfer_size = 0;
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if (xfer->tx_buf) {
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len = xfer->len - spi->tx_xfer_offset;
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if (!tx_header_fit_operation(tx_size, count, data_max))
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break;
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tx_xfer_size = calc_tx_xfer_size(tx_size, count,
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len, data_max);
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spi->last_xfer_size = tx_xfer_size;
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}
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if (xfer->rx_buf) {
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len = xfer->len - spi->rx_xfer_offset;
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rx_xfer_size = calc_rx_xfer_size(rx_size, &tx_xfer_size,
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len, data_max);
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spi->last_xfer_size = rx_xfer_size;
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}
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tx_size += tx_xfer_size;
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rx_size += rx_xfer_size;
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total_len += spi->last_xfer_size;
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count++;
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xfer = get_next_xfer(xfer, msg);
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if (!xfer || total_len >= data_max)
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msg->state = GB_SPI_STATE_OP_READY;
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}
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/*
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* In addition to space for all message descriptors we need
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* to have enough to hold all tx data.
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*/
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request_size = sizeof(*request);
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request_size += count * sizeof(*gb_xfer);
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request_size += tx_size;
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/* Response consists only of incoming data */
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operation = gb_operation_create(connection, GB_SPI_TYPE_TRANSFER,
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request_size, rx_size, GFP_KERNEL);
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if (!operation)
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return NULL;
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request = operation->request->payload;
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request->count = cpu_to_le16(count);
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request->mode = dev->mode;
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request->chip_select = dev->chip_select;
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gb_xfer = &request->transfers[0];
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tx_data = gb_xfer + count; /* place tx data after last gb_xfer */
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/* Fill in the transfers array */
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xfer = spi->first_xfer;
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while (msg->state != GB_SPI_STATE_OP_DONE) {
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if (xfer == spi->last_xfer)
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xfer_len = spi->last_xfer_size;
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else
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xfer_len = xfer->len;
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/* make sure we do not timeout in a slow transfer */
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xfer_timeout = xfer_len * 8 * MSEC_PER_SEC / xfer->speed_hz;
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xfer_timeout += GB_OPERATION_TIMEOUT_DEFAULT;
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if (xfer_timeout > spi->op_timeout)
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spi->op_timeout = xfer_timeout;
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gb_xfer->speed_hz = cpu_to_le32(xfer->speed_hz);
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gb_xfer->len = cpu_to_le32(xfer_len);
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gb_xfer->delay_usecs = cpu_to_le16(xfer->delay_usecs);
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gb_xfer->cs_change = xfer->cs_change;
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gb_xfer->bits_per_word = xfer->bits_per_word;
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/* Copy tx data */
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if (xfer->tx_buf) {
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gb_xfer->xfer_flags |= GB_SPI_XFER_WRITE;
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memcpy(tx_data, xfer->tx_buf + spi->tx_xfer_offset,
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xfer_len);
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tx_data += xfer_len;
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}
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if (xfer->rx_buf)
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gb_xfer->xfer_flags |= GB_SPI_XFER_READ;
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if (xfer == spi->last_xfer) {
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if (!is_last_xfer_done(spi))
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gb_xfer->xfer_flags |= GB_SPI_XFER_INPROGRESS;
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msg->state = GB_SPI_STATE_OP_DONE;
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continue;
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}
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gb_xfer++;
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xfer = get_next_xfer(xfer, msg);
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}
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msg->actual_length += total_len;
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return operation;
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}
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static void gb_spi_decode_response(struct gb_spilib *spi,
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struct spi_message *msg,
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struct gb_spi_transfer_response *response)
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{
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struct spi_transfer *xfer = spi->first_xfer;
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void *rx_data = response->data;
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u32 xfer_len;
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while (xfer) {
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/* Copy rx data */
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if (xfer->rx_buf) {
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if (xfer == spi->first_xfer)
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xfer_len = xfer->len - spi->rx_xfer_offset;
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else if (xfer == spi->last_xfer)
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xfer_len = spi->last_xfer_size;
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else
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xfer_len = xfer->len;
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memcpy(xfer->rx_buf + spi->rx_xfer_offset, rx_data,
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xfer_len);
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rx_data += xfer_len;
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}
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if (xfer == spi->last_xfer)
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break;
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xfer = list_next_entry(xfer, transfer_list);
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}
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}
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static int gb_spi_transfer_one_message(struct spi_master *master,
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struct spi_message *msg)
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{
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struct gb_spilib *spi = spi_master_get_devdata(master);
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struct gb_connection *connection = spi->connection;
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struct gb_spi_transfer_response *response;
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struct gb_operation *operation;
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int ret = 0;
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spi->first_xfer = list_first_entry_or_null(&msg->transfers,
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struct spi_transfer,
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transfer_list);
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if (!spi->first_xfer) {
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ret = -ENOMEM;
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goto out;
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}
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msg->state = GB_SPI_STATE_MSG_IDLE;
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while (msg->state != GB_SPI_STATE_MSG_DONE &&
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msg->state != GB_SPI_STATE_MSG_ERROR) {
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operation = gb_spi_operation_create(spi, connection, msg);
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if (!operation) {
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msg->state = GB_SPI_STATE_MSG_ERROR;
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ret = -EINVAL;
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continue;
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}
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ret = gb_operation_request_send_sync_timeout(operation,
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spi->op_timeout);
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if (!ret) {
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response = operation->response->payload;
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if (response)
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gb_spi_decode_response(spi, msg, response);
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} else {
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dev_err(spi->parent,
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"transfer operation failed: %d\n", ret);
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msg->state = GB_SPI_STATE_MSG_ERROR;
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}
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gb_operation_put(operation);
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setup_next_xfer(spi, msg);
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}
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out:
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msg->status = ret;
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clean_xfer_state(spi);
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spi_finalize_current_message(master);
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return ret;
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}
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static int gb_spi_prepare_transfer_hardware(struct spi_master *master)
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{
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struct gb_spilib *spi = spi_master_get_devdata(master);
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return spi->ops->prepare_transfer_hardware(spi->parent);
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}
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static int gb_spi_unprepare_transfer_hardware(struct spi_master *master)
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{
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struct gb_spilib *spi = spi_master_get_devdata(master);
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spi->ops->unprepare_transfer_hardware(spi->parent);
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return 0;
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}
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static int gb_spi_setup(struct spi_device *spi)
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{
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/* Nothing to do for now */
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return 0;
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}
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static void gb_spi_cleanup(struct spi_device *spi)
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{
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/* Nothing to do for now */
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}
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/* Routines to get controller information */
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/*
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* Map Greybus spi mode bits/flags/bpw into Linux ones.
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* All bits are same for now and so these macro's return same values.
|
*/
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#define gb_spi_mode_map(mode) mode
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#define gb_spi_flags_map(flags) flags
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static int gb_spi_get_master_config(struct gb_spilib *spi)
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{
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struct gb_spi_master_config_response response;
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u16 mode, flags;
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int ret;
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ret = gb_operation_sync(spi->connection, GB_SPI_TYPE_MASTER_CONFIG,
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NULL, 0, &response, sizeof(response));
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if (ret < 0)
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return ret;
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mode = le16_to_cpu(response.mode);
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spi->mode = gb_spi_mode_map(mode);
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flags = le16_to_cpu(response.flags);
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spi->flags = gb_spi_flags_map(flags);
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spi->bits_per_word_mask = le32_to_cpu(response.bits_per_word_mask);
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spi->num_chipselect = response.num_chipselect;
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spi->min_speed_hz = le32_to_cpu(response.min_speed_hz);
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spi->max_speed_hz = le32_to_cpu(response.max_speed_hz);
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return 0;
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}
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static int gb_spi_setup_device(struct gb_spilib *spi, u8 cs)
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{
|
struct spi_master *master = get_master_from_spi(spi);
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struct gb_spi_device_config_request request;
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struct gb_spi_device_config_response response;
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struct spi_board_info spi_board = { {0} };
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struct spi_device *spidev;
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int ret;
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u8 dev_type;
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request.chip_select = cs;
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ret = gb_operation_sync(spi->connection, GB_SPI_TYPE_DEVICE_CONFIG,
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&request, sizeof(request),
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&response, sizeof(response));
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if (ret < 0)
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return ret;
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dev_type = response.device_type;
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if (dev_type == GB_SPI_SPI_DEV)
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strlcpy(spi_board.modalias, "spidev",
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sizeof(spi_board.modalias));
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else if (dev_type == GB_SPI_SPI_NOR)
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strlcpy(spi_board.modalias, "spi-nor",
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sizeof(spi_board.modalias));
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else if (dev_type == GB_SPI_SPI_MODALIAS)
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memcpy(spi_board.modalias, response.name,
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sizeof(spi_board.modalias));
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else
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return -EINVAL;
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spi_board.mode = le16_to_cpu(response.mode);
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spi_board.bus_num = master->bus_num;
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spi_board.chip_select = cs;
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spi_board.max_speed_hz = le32_to_cpu(response.max_speed_hz);
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spidev = spi_new_device(master, &spi_board);
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if (!spidev)
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return -EINVAL;
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return 0;
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}
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int gb_spilib_master_init(struct gb_connection *connection, struct device *dev,
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struct spilib_ops *ops)
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{
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struct gb_spilib *spi;
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struct spi_master *master;
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int ret;
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u8 i;
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/* Allocate master with space for data */
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master = spi_alloc_master(dev, sizeof(*spi));
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if (!master) {
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dev_err(dev, "cannot alloc SPI master\n");
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return -ENOMEM;
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}
|
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spi = spi_master_get_devdata(master);
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spi->connection = connection;
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gb_connection_set_data(connection, master);
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spi->parent = dev;
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spi->ops = ops;
|
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/* get master configuration */
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ret = gb_spi_get_master_config(spi);
|
if (ret)
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goto exit_spi_put;
|
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master->bus_num = -1; /* Allow spi-core to allocate it dynamically */
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master->num_chipselect = spi->num_chipselect;
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master->mode_bits = spi->mode;
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master->flags = spi->flags;
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master->bits_per_word_mask = spi->bits_per_word_mask;
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/* Attach methods */
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master->cleanup = gb_spi_cleanup;
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master->setup = gb_spi_setup;
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master->transfer_one_message = gb_spi_transfer_one_message;
|
|
if (ops && ops->prepare_transfer_hardware) {
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master->prepare_transfer_hardware =
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gb_spi_prepare_transfer_hardware;
|
}
|
|
if (ops && ops->unprepare_transfer_hardware) {
|
master->unprepare_transfer_hardware =
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gb_spi_unprepare_transfer_hardware;
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}
|
|
master->auto_runtime_pm = true;
|
|
ret = spi_register_master(master);
|
if (ret < 0)
|
goto exit_spi_put;
|
|
/* now, fetch the devices configuration */
|
for (i = 0; i < spi->num_chipselect; i++) {
|
ret = gb_spi_setup_device(spi, i);
|
if (ret < 0) {
|
dev_err(dev, "failed to allocate spi device %d: %d\n",
|
i, ret);
|
goto exit_spi_unregister;
|
}
|
}
|
|
return 0;
|
|
exit_spi_put:
|
spi_master_put(master);
|
|
return ret;
|
|
exit_spi_unregister:
|
spi_unregister_master(master);
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(gb_spilib_master_init);
|
|
void gb_spilib_master_exit(struct gb_connection *connection)
|
{
|
struct spi_master *master = gb_connection_get_data(connection);
|
|
spi_unregister_master(master);
|
}
|
EXPORT_SYMBOL_GPL(gb_spilib_master_exit);
|
|
MODULE_LICENSE("GPL v2");
|
