^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * SPI slave handler reporting uptime at reception of previous SPI message
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * This SPI slave handler sends the time of reception of the last SPI message
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * as two 32-bit unsigned integers in binary format and in network byte order,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * representing the number of seconds and fractional seconds (in microseconds)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * since boot up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Copyright (C) 2016-2017 Glider bvba
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * This file is subject to the terms and conditions of the GNU General Public
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * License. See the file "COPYING" in the main directory of this archive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * Usage (assuming /dev/spidev2.0 corresponds to the SPI master on the remote
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * system):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * # spidev_test -D /dev/spidev2.0 -p dummy-8B
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * spi mode: 0x0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * bits per word: 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * max speed: 500000 Hz (500 KHz)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * RX | 00 00 04 6D 00 09 5B BB ...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) * ^^^^^ ^^^^^^^^
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * seconds microseconds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/completion.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <linux/sched/clock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <linux/spi/spi.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) struct spi_slave_time_priv {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) struct spi_device *spi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) struct completion finished;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) struct spi_transfer xfer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) struct spi_message msg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) __be32 buf[2];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) static int spi_slave_time_submit(struct spi_slave_time_priv *priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) static void spi_slave_time_complete(void *arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) struct spi_slave_time_priv *priv = arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) ret = priv->msg.status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) goto terminate;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) ret = spi_slave_time_submit(priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) goto terminate;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) terminate:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) dev_info(&priv->spi->dev, "Terminating\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) complete(&priv->finished);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) static int spi_slave_time_submit(struct spi_slave_time_priv *priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) u32 rem_us;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) u64 ts;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) ts = local_clock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) rem_us = do_div(ts, 1000000000) / 1000;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) priv->buf[0] = cpu_to_be32(ts);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) priv->buf[1] = cpu_to_be32(rem_us);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) spi_message_init_with_transfers(&priv->msg, &priv->xfer, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) priv->msg.complete = spi_slave_time_complete;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) priv->msg.context = priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) ret = spi_async(priv->spi, &priv->msg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) dev_err(&priv->spi->dev, "spi_async() failed %d\n", ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) static int spi_slave_time_probe(struct spi_device *spi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) struct spi_slave_time_priv *priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) if (!priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) priv->spi = spi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) init_completion(&priv->finished);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) priv->xfer.tx_buf = priv->buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) priv->xfer.len = sizeof(priv->buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) ret = spi_slave_time_submit(priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) spi_set_drvdata(spi, priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) static int spi_slave_time_remove(struct spi_device *spi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) struct spi_slave_time_priv *priv = spi_get_drvdata(spi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) spi_slave_abort(spi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) wait_for_completion(&priv->finished);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) static struct spi_driver spi_slave_time_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) .driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) .name = "spi-slave-time",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) .probe = spi_slave_time_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) .remove = spi_slave_time_remove,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) module_spi_driver(spi_slave_time_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) MODULE_DESCRIPTION("SPI slave reporting uptime at previous SPI message");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) MODULE_LICENSE("GPL v2");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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