spi: altera: separate core code from platform code

In preparation of adding support for a new bus type,
separate the core spi-altera code from the platform
driver code.

Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Link: https://lore.kernel.org/r/20210416165720.554144-2-matthew.gerlach@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

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 000000000000..f7a7c14e3679
--- /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 = pdev->id;
+
+	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);