diff options
Diffstat (limited to 'meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0087-spi-slave-Add-SPI-slave-handler-reporting-uptime-at-.patch')
| -rw-r--r-- | meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0087-spi-slave-Add-SPI-slave-handler-reporting-uptime-at-.patch | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0087-spi-slave-Add-SPI-slave-handler-reporting-uptime-at-.patch b/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0087-spi-slave-Add-SPI-slave-handler-reporting-uptime-at-.patch new file mode 100644 index 0000000..1c9be85 --- /dev/null +++ b/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0087-spi-slave-Add-SPI-slave-handler-reporting-uptime-at-.patch @@ -0,0 +1,182 @@ +From 8b3a09269db92be56455d98bc8cb01f779733f0a Mon Sep 17 00:00:00 2001 +From: Geert Uytterhoeven <geert+renesas@glider.be> +Date: Fri, 17 Jun 2016 17:00:25 +0200 +Subject: [PATCH 5/7] spi: slave: Add SPI slave handler reporting uptime at + previous message + +Add an example SPI slave handler responding with the uptime at the time +of reception of the last SPI message. + +This can be used by an external microcontroller as a dead man's switch. + +Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> +--- + drivers/spi/Kconfig | 6 ++ + drivers/spi/Makefile | 1 + + drivers/spi/spi-slave-time.c | 129 ++++++++++++++++++++++++++++++++++++++++++ + 3 files changed, 136 insertions(+) + create mode 100644 drivers/spi/spi-slave-time.c + +diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig +index 8c97790..267bedf 100644 +--- a/drivers/spi/Kconfig ++++ b/drivers/spi/Kconfig +@@ -793,6 +793,12 @@ config SPI_SLAVE + + if SPI_SLAVE + ++config SPI_SLAVE_TIME ++ tristate "SPI slave handler reporting boot up time" ++ help ++ SPI slave handler responding with the time of reception of the last ++ SPI message. ++ + endif # SPI_SLAVE + + endif # SPI +diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile +index 2428b0f..5e2e537 100644 +--- a/drivers/spi/Makefile ++++ b/drivers/spi/Makefile +@@ -104,3 +104,4 @@ obj-$(CONFIG_SPI_XTENSA_XTFPGA) += spi-xtensa-xtfpga.o + obj-$(CONFIG_SPI_ZYNQMP_GQSPI) += spi-zynqmp-gqspi.o + + # SPI slave protocol handlers ++obj-$(CONFIG_SPI_SLAVE_TIME) += spi-slave-time.o +diff --git a/drivers/spi/spi-slave-time.c b/drivers/spi/spi-slave-time.c +new file mode 100644 +index 0000000..fbeaa5b +--- /dev/null ++++ b/drivers/spi/spi-slave-time.c +@@ -0,0 +1,129 @@ ++/* ++ * SPI slave handler reporting uptime at reception of previous SPI message ++ * ++ * This SPI slave handler sends the time of reception of the last SPI message ++ * as two 32-bit unsigned integers in binary format and in network byte order, ++ * representing the number of seconds and fractional seconds (in microseconds) ++ * since boot up. ++ * ++ * Copyright (C) 2016-2017 Glider bvba ++ * ++ * This file is subject to the terms and conditions of the GNU General Public ++ * License. See the file "COPYING" in the main directory of this archive ++ * for more details. ++ * ++ * Usage (assuming /dev/spidev2.0 corresponds to the SPI master on the remote ++ * system): ++ * ++ * # spidev_test -D /dev/spidev2.0 -p dummy-8B ++ * spi mode: 0x0 ++ * bits per word: 8 ++ * max speed: 500000 Hz (500 KHz) ++ * RX | 00 00 04 6D 00 09 5B BB ... ++ * ^^^^^ ^^^^^^^^ ++ * seconds microseconds ++ */ ++ ++#include <linux/completion.h> ++#include <linux/module.h> ++#include <linux/sched.h> ++#include <linux/spi/spi.h> ++ ++ ++struct spi_slave_time_priv { ++ struct spi_device *spi; ++ struct completion finished; ++ struct spi_transfer xfer; ++ struct spi_message msg; ++ __be32 buf[2]; ++}; ++ ++static int spi_slave_time_submit(struct spi_slave_time_priv *priv); ++ ++static void spi_slave_time_complete(void *arg) ++{ ++ struct spi_slave_time_priv *priv = arg; ++ int ret; ++ ++ ret = priv->msg.status; ++ if (ret) ++ goto terminate; ++ ++ ret = spi_slave_time_submit(priv); ++ if (ret) ++ goto terminate; ++ ++ return; ++ ++terminate: ++ dev_info(&priv->spi->dev, "Terminating\n"); ++ complete(&priv->finished); ++} ++ ++static int spi_slave_time_submit(struct spi_slave_time_priv *priv) ++{ ++ u32 rem_us; ++ int ret; ++ u64 ts; ++ ++ ts = local_clock(); ++ rem_us = do_div(ts, 1000000000) / 1000; ++ ++ priv->buf[0] = cpu_to_be32(ts); ++ priv->buf[1] = cpu_to_be32(rem_us); ++ ++ spi_message_init_with_transfers(&priv->msg, &priv->xfer, 1); ++ ++ priv->msg.complete = spi_slave_time_complete; ++ priv->msg.context = priv; ++ ++ ret = spi_async(priv->spi, &priv->msg); ++ if (ret) ++ dev_err(&priv->spi->dev, "spi_async() failed %d\n", ret); ++ ++ return ret; ++} ++ ++static int spi_slave_time_probe(struct spi_device *spi) ++{ ++ struct spi_slave_time_priv *priv; ++ int ret; ++ ++ priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL); ++ if (!priv) ++ return -ENOMEM; ++ ++ priv->spi = spi; ++ init_completion(&priv->finished); ++ priv->xfer.tx_buf = priv->buf; ++ priv->xfer.len = sizeof(priv->buf); ++ ++ ret = spi_slave_time_submit(priv); ++ if (ret) ++ return ret; ++ ++ spi_set_drvdata(spi, priv); ++ return 0; ++} ++ ++static int spi_slave_time_remove(struct spi_device *spi) ++{ ++ struct spi_slave_time_priv *priv = spi_get_drvdata(spi); ++ ++ spi_slave_abort(spi); ++ wait_for_completion(&priv->finished); ++ return 0; ++} ++ ++static struct spi_driver spi_slave_time_driver = { ++ .driver = { ++ .name = "spi-slave-time", ++ }, ++ .probe = spi_slave_time_probe, ++ .remove = spi_slave_time_remove, ++}; ++module_spi_driver(spi_slave_time_driver); ++ ++MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>"); ++MODULE_DESCRIPTION("SPI slave reporting uptime at previous SPI message"); ++MODULE_LICENSE("GPL v2"); +-- +1.7.10.4 |