/* * SPI OF support routines * Copyright (C) 2008 Secret Lab Technologies Ltd. * * Support routines for deriving SPI device attachments from the device * tree. */ #include <linux/of.h> #include <linux/device.h> #include <linux/spi/spi.h> #include <linux/of_spi.h> /** * of_register_spi_devices - Register child devices onto the SPI bus * @master: Pointer to spi_master device * @np: parent node of SPI device nodes * * Registers an spi_device for each child node of 'np' which has a 'reg' * property. */ void of_register_spi_devices(struct spi_master *master, struct device_node *np) { struct spi_device *spi; struct device_node *nc; const u32 *prop; int rc; int len; for_each_child_of_node(np, nc) { /* Alloc an spi_device */ spi = spi_alloc_device(master); if (!spi) { dev_err(&master->dev, "spi_device alloc error for %s\n", nc->full_name); spi_dev_put(spi); continue; } /* Select device driver */ if (of_modalias_node(nc, spi->modalias, sizeof(spi->modalias)) < 0) { dev_err(&master->dev, "cannot find modalias for %s\n", nc->full_name); spi_dev_put(spi); continue; } /* Device address */ prop = of_get_property(nc, "reg", &len); if (!prop || len < sizeof(*prop)) { dev_err(&master->dev, "%s has no 'reg' property\n", nc->full_name); spi_dev_put(spi); continue; } spi->chip_select = *prop; /* Mode (clock phase/polarity/etc.) */ if (of_find_property(nc, "spi-cpha", NULL)) spi->mode |= SPI_CPHA; if (of_find_property(nc, "spi-cpol", NULL)) spi->mode |= SPI_CPOL; if (of_find_property(nc, "spi-cs-high", NULL)) spi->mode |= SPI_CS_HIGH; /* Device speed */ prop = of_get_property(nc, "spi-max-frequency", &len); if (!prop || len < sizeof(*prop)) { dev_err(&master->dev, "%s has no 'spi-max-frequency' property\n", nc->full_name); spi_dev_put(spi); continue; } spi->max_speed_hz = *prop; /* IRQ */ spi->irq = irq_of_parse_and_map(nc, 0); /* Store a pointer to the node in the device structure */ of_node_get(nc); spi->dev.archdata.of_node = nc; /* Register the new device */ request_module(spi->modalias); rc = spi_add_device(spi); if (rc) { dev_err(&master->dev, "spi_device register error %s\n", nc->full_name); spi_dev_put(spi); } } } EXPORT_SYMBOL(of_register_spi_devices);