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![Stefan Wahren](/assets/img/avatar_default.png)
The SPI protocol for the QCA7000 doesn't have any fault detection. In order to increase the drivers reliability in noisy environments, we could implement a write verification inspired by the enc28j60. This should avoid situations were the driver wrongly assumes the receive interrupt is enabled and miss all incoming packets. This function is disabled per default and can be controlled via module parameter wr_verify. Signed-off-by: Michael Heimpold <michael.heimpold@i2se.com> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: David S. Miller <davem@davemloft.net>
149 lines
3.2 KiB
C
149 lines
3.2 KiB
C
/*
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*
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* Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
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* Copyright (c) 2014, I2SE GmbH
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*
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* Permission to use, copy, modify, and/or distribute this software
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* for any purpose with or without fee is hereby granted, provided
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* that the above copyright notice and this permission notice appear
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* in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
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* WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
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* THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
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* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
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* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
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* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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*/
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/* This module implements the Qualcomm Atheros SPI protocol for
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* kernel-based SPI device.
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*/
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#include <linux/kernel.h>
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#include <linux/netdevice.h>
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#include <linux/spi/spi.h>
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#include "qca_7k.h"
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void
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qcaspi_spi_error(struct qcaspi *qca)
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{
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if (qca->sync != QCASPI_SYNC_READY)
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return;
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netdev_err(qca->net_dev, "spi error\n");
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qca->sync = QCASPI_SYNC_UNKNOWN;
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qca->stats.spi_err++;
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}
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int
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qcaspi_read_register(struct qcaspi *qca, u16 reg, u16 *result)
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{
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__be16 rx_data;
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__be16 tx_data;
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struct spi_transfer transfer[2];
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struct spi_message msg;
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int ret;
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memset(transfer, 0, sizeof(transfer));
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spi_message_init(&msg);
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tx_data = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_INTERNAL | reg);
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*result = 0;
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transfer[0].tx_buf = &tx_data;
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transfer[0].len = QCASPI_CMD_LEN;
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transfer[1].rx_buf = &rx_data;
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transfer[1].len = QCASPI_CMD_LEN;
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spi_message_add_tail(&transfer[0], &msg);
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if (qca->legacy_mode) {
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spi_sync(qca->spi_dev, &msg);
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spi_message_init(&msg);
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}
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spi_message_add_tail(&transfer[1], &msg);
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ret = spi_sync(qca->spi_dev, &msg);
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if (!ret)
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ret = msg.status;
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if (ret)
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qcaspi_spi_error(qca);
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else
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*result = be16_to_cpu(rx_data);
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return ret;
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}
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static int
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__qcaspi_write_register(struct qcaspi *qca, u16 reg, u16 value)
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{
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__be16 tx_data[2];
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struct spi_transfer transfer[2];
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struct spi_message msg;
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int ret;
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memset(&transfer, 0, sizeof(transfer));
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spi_message_init(&msg);
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tx_data[0] = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_INTERNAL | reg);
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tx_data[1] = cpu_to_be16(value);
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transfer[0].tx_buf = &tx_data[0];
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transfer[0].len = QCASPI_CMD_LEN;
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transfer[1].tx_buf = &tx_data[1];
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transfer[1].len = QCASPI_CMD_LEN;
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spi_message_add_tail(&transfer[0], &msg);
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if (qca->legacy_mode) {
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spi_sync(qca->spi_dev, &msg);
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spi_message_init(&msg);
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}
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spi_message_add_tail(&transfer[1], &msg);
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ret = spi_sync(qca->spi_dev, &msg);
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if (!ret)
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ret = msg.status;
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if (ret)
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qcaspi_spi_error(qca);
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return ret;
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}
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int
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qcaspi_write_register(struct qcaspi *qca, u16 reg, u16 value, int retry)
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{
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int ret, i = 0;
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u16 confirmed;
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do {
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ret = __qcaspi_write_register(qca, reg, value);
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if (ret)
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return ret;
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if (!retry)
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return 0;
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ret = qcaspi_read_register(qca, reg, &confirmed);
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if (ret)
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return ret;
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ret = confirmed != value;
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if (!ret)
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return 0;
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i++;
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qca->stats.write_verify_failed++;
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} while (i <= retry);
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return ret;
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}
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