diff options
Diffstat (limited to 'drivers/spi/spi-altera-platform.c')
| -rw-r--r-- | drivers/spi/spi-altera-platform.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/drivers/spi/spi-altera-platform.c b/drivers/spi/spi-altera-platform.c new file mode 100644 index 000000000..65147aae8 --- /dev/null +++ b/drivers/spi/spi-altera-platform.c @@ -0,0 +1,172 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Altera SPI driver + * + * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw> + * + * Based on spi_s3c24xx.c, which is: + * Copyright (c) 2006 Ben Dooks + * Copyright (c) 2006 Simtec Electronics + * Ben Dooks <ben@simtec.co.uk> + */ + +#include <linux/interrupt.h> +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/spi/altera.h> +#include <linux/spi/spi.h> +#include <linux/io.h> +#include <linux/of.h> + +#define DRV_NAME "spi_altera" + +enum altera_spi_type { + ALTERA_SPI_TYPE_UNKNOWN, + ALTERA_SPI_TYPE_SUBDEV, +}; + +static const struct regmap_config spi_altera_config = { + .reg_bits = 32, + .reg_stride = 4, + .val_bits = 32, + .fast_io = true, +}; + +static int altera_spi_probe(struct platform_device *pdev) +{ + const struct platform_device_id *platid = platform_get_device_id(pdev); + struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev); + enum altera_spi_type type = ALTERA_SPI_TYPE_UNKNOWN; + struct altera_spi *hw; + struct spi_master *master; + int err = -ENODEV; + u16 i; + + master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi)); + if (!master) + return err; + + /* setup the master state. */ + master->bus_num = -1; + + if (pdata) { + if (pdata->num_chipselect > ALTERA_SPI_MAX_CS) { + dev_err(&pdev->dev, + "Invalid number of chipselect: %u\n", + pdata->num_chipselect); + err = -EINVAL; + goto exit; + } + + master->num_chipselect = pdata->num_chipselect; + master->mode_bits = pdata->mode_bits; + master->bits_per_word_mask = pdata->bits_per_word_mask; + } else { + master->num_chipselect = 16; + master->mode_bits = SPI_CS_HIGH; + master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16); + } + + master->dev.of_node = pdev->dev.of_node; + + hw = spi_master_get_devdata(master); + hw->dev = &pdev->dev; + + if (platid) + type = platid->driver_data; + + /* find and map our resources */ + if (type == ALTERA_SPI_TYPE_SUBDEV) { + struct resource *regoff; + + hw->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!hw->regmap) { + dev_err(&pdev->dev, "get regmap failed\n"); + goto exit; + } + + regoff = platform_get_resource(pdev, IORESOURCE_REG, 0); + if (regoff) + hw->regoff = regoff->start; + } else { + void __iomem *res; + + res = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(res)) { + err = PTR_ERR(res); + goto exit; + } + + hw->regmap = devm_regmap_init_mmio(&pdev->dev, res, + &spi_altera_config); + if (IS_ERR(hw->regmap)) { + dev_err(&pdev->dev, "regmap mmio init failed\n"); + err = PTR_ERR(hw->regmap); + goto exit; + } + } + + altera_spi_init_master(master); + + /* irq is optional */ + hw->irq = platform_get_irq(pdev, 0); + if (hw->irq >= 0) { + err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0, + pdev->name, master); + if (err) + goto exit; + } + + err = devm_spi_register_master(&pdev->dev, master); + if (err) + goto exit; + + if (pdata) { + for (i = 0; i < pdata->num_devices; i++) { + if (!spi_new_device(master, pdata->devices + i)) + dev_warn(&pdev->dev, + "unable to create SPI device: %s\n", + pdata->devices[i].modalias); + } + } + + dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq); + + return 0; +exit: + spi_master_put(master); + return err; +} + +#ifdef CONFIG_OF +static const struct of_device_id altera_spi_match[] = { + { .compatible = "ALTR,spi-1.0", }, + { .compatible = "altr,spi-1.0", }, + {}, +}; +MODULE_DEVICE_TABLE(of, altera_spi_match); +#endif /* CONFIG_OF */ + +static const struct platform_device_id altera_spi_ids[] = { + { DRV_NAME, ALTERA_SPI_TYPE_UNKNOWN }, + { "subdev_spi_altera", ALTERA_SPI_TYPE_SUBDEV }, + { } +}; +MODULE_DEVICE_TABLE(platform, altera_spi_ids); + +static struct platform_driver altera_spi_driver = { + .probe = altera_spi_probe, + .driver = { + .name = DRV_NAME, + .pm = NULL, + .of_match_table = of_match_ptr(altera_spi_match), + }, + .id_table = altera_spi_ids, +}; +module_platform_driver(altera_spi_driver); + +MODULE_DESCRIPTION("Altera SPI driver"); +MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRV_NAME); |