2  * SPI slave handler controlling system state
4  * This SPI slave handler allows remote control of system reboot, power off,
7  * Copyright (C) 2016-2017 Glider bvba
13  * Usage (assuming /dev/spidev2.0 corresponds to the SPI master on the remote
20  *   # spidev_test -D /dev/spidev2.0 -p $suspend # or $reboot, $poweroff, $halt
27 #include <linux/spi/spi.h>
30  * The numbers are chosen to display something human-readable on two 7-segment
39 	struct spi_device *spi;  member
55 	if (priv->msg.status)  in spi_slave_system_control_complete()
58 	cmd = be16_to_cpu(priv->cmd);  in spi_slave_system_control_complete()
61 		dev_info(&priv->spi->dev, "Rebooting system...\n");  in spi_slave_system_control_complete()
66 		dev_info(&priv->spi->dev, "Powering off system...\n");  in spi_slave_system_control_complete()
71 		dev_info(&priv->spi->dev, "Halting system...\n");  in spi_slave_system_control_complete()
76 		dev_info(&priv->spi->dev, "Suspending system...\n");  in spi_slave_system_control_complete()
81 		dev_warn(&priv->spi->dev, "Unknown command 0x%x\n", cmd);  in spi_slave_system_control_complete()
92 	dev_info(&priv->spi->dev, "Terminating\n");  in spi_slave_system_control_complete()
93 	complete(&priv->finished);  in spi_slave_system_control_complete()
101 	spi_message_init_with_transfers(&priv->msg, &priv->xfer, 1);  in spi_slave_system_control_submit()
103 	priv->msg.complete = spi_slave_system_control_complete;  in spi_slave_system_control_submit()
104 	priv->msg.context = priv;  in spi_slave_system_control_submit()
106 	ret = spi_async(priv->spi, &priv->msg);  in spi_slave_system_control_submit()
108 		dev_err(&priv->spi->dev, "spi_async() failed %d\n", ret);  in spi_slave_system_control_submit()
113 static int spi_slave_system_control_probe(struct spi_device *spi)  in spi_slave_system_control_probe()  argument
118 	priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);  in spi_slave_system_control_probe()
120 		return -ENOMEM;  in spi_slave_system_control_probe()
122 	priv->spi = spi;  in spi_slave_system_control_probe()
123 	init_completion(&priv->finished);  in spi_slave_system_control_probe()
124 	priv->xfer.rx_buf = &priv->cmd;  in spi_slave_system_control_probe()
125 	priv->xfer.len = sizeof(priv->cmd);  in spi_slave_system_control_probe()
131 	spi_set_drvdata(spi, priv);  in spi_slave_system_control_probe()
135 static void spi_slave_system_control_remove(struct spi_device *spi)  in spi_slave_system_control_remove()  argument
137 	struct spi_slave_system_control_priv *priv = spi_get_drvdata(spi);  in spi_slave_system_control_remove()
139 	spi_target_abort(spi);  in spi_slave_system_control_remove()
140 	wait_for_completion(&priv->finished);  in spi_slave_system_control_remove()
145 		.name	= "spi-slave-system-control",
153 MODULE_DESCRIPTION("SPI slave handler controlling system state");