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>

drivers/spi/Kconfig

@@ -58,11 +58,18 @@ config SPI_MEM
 comment "SPI Master Controller Drivers"
 
 config SPI_ALTERA
-	tristate "Altera SPI Controller"
+	tristate "Altera SPI Controller platform driver"
+	select SPI_ALTERA_CORE
 	select REGMAP_MMIO
 	help
 	  This is the driver for the Altera SPI Controller.
 
+config SPI_ALTERA_CORE
+	tristate "Altera SPI Controller core code"
+	select REGMAP
+	help
+	  "The core code for the Altera SPI Controller"
+
 config SPI_AR934X
 	tristate "Qualcomm Atheros AR934X/QCA95XX SPI controller driver"
 	depends on ATH79 || COMPILE_TEST

drivers/spi/Makefile

@@ -14,7 +14,8 @@ obj-$(CONFIG_SPI_SPIDEV)		+= spidev.o
 obj-$(CONFIG_SPI_LOOPBACK_TEST)		+= spi-loopback-test.o
 
 # SPI master controller drivers (bus)
-obj-$(CONFIG_SPI_ALTERA)		+= spi-altera.o
+obj-$(CONFIG_SPI_ALTERA)		+= spi-altera-platform.o
+obj-$(CONFIG_SPI_ALTERA_CORE)		+= spi-altera-core.o
 obj-$(CONFIG_SPI_AR934X)		+= spi-ar934x.o
 obj-$(CONFIG_SPI_ARMADA_3700)		+= spi-armada-3700.o
 obj-$(CONFIG_SPI_ATMEL)			+= spi-atmel.o

drivers/spi/spi-altera-core.c

@@ -10,7 +10,6 @@
  *	Ben Dooks <ben@simtec.co.uk>
  */
 
-#include <linux/interrupt.h>
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
@@ -41,36 +40,6 @@
 #define ALTERA_SPI_CONTROL_IE_MSK	0x100
 #define ALTERA_SPI_CONTROL_SSO_MSK	0x400
 
-#define ALTERA_SPI_MAX_CS		32
-
-enum altera_spi_type {
-	ALTERA_SPI_TYPE_UNKNOWN,
-	ALTERA_SPI_TYPE_SUBDEV,
-};
-
-struct altera_spi {
-	int irq;
-	int len;
-	int count;
-	int bytes_per_word;
-	u32 imr;
-
-	/* data buffers */
-	const unsigned char *tx;
-	unsigned char *rx;
-
-	struct regmap *regmap;
-	u32 regoff;
-	struct device *dev;
-};
-
-static const struct regmap_config spi_altera_config = {
-	.reg_bits = 32,
-	.reg_stride = 4,
-	.val_bits = 32,
-	.fast_io = true,
-};
-
 static int altr_spi_writel(struct altera_spi *hw, unsigned int reg,
 			   unsigned int val)
 {
@@ -211,7 +180,7 @@ static int altera_spi_txrx(struct spi_master *master,
 	return 0;
 }
 
-static irqreturn_t altera_spi_irq(int irq, void *dev)
+irqreturn_t altera_spi_irq(int irq, void *dev)
 {
 	struct spi_master *master = dev;
 	struct altera_spi *hw = spi_master_get_devdata(master);
@@ -230,84 +199,16 @@ static irqreturn_t altera_spi_irq(int irq, void *dev)
 
 	return IRQ_HANDLED;
 }
+EXPORT_SYMBOL_GPL(altera_spi_irq);
 
-static int altera_spi_probe(struct platform_device *pdev)
+void altera_spi_init_master(struct spi_master *master)
 {
-	const struct platform_device_id *platid = platform_get_device_id(pdev);
+	struct altera_spi *hw = spi_master_get_devdata(master);
-	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;
 	u32 val;
-	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: %hu\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;
 	master->transfer_one = altera_spi_txrx;
 	master->set_cs = altera_spi_set_cs;
 
-	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;
-		}
-	}
-
 	/* program defaults into the registers */
 	hw->imr = 0;		/* disable spi interrupts */
 	altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
@@ -315,64 +216,7 @@ static int altera_spi_probe(struct platform_device *pdev)
 	altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
 	if (val & ALTERA_SPI_STATUS_RRDY_MSK)
 		altr_spi_readl(hw, ALTERA_SPI_RXDATA, &val); /* flush rxdata */
-	/* 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;
 }
+EXPORT_SYMBOL_GPL(altera_spi_init_master);
 
-#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);

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);

include/linux/spi/altera.h

@@ -5,10 +5,13 @@
 #ifndef __LINUX_SPI_ALTERA_H
 #define __LINUX_SPI_ALTERA_H
 
+#include <linux/interrupt.h>
 #include <linux/regmap.h>
 #include <linux/spi/spi.h>
 #include <linux/types.h>
 
+#define ALTERA_SPI_MAX_CS		32
+
 /**
  * struct altera_spi_platform_data - Platform data of the Altera SPI driver
  * @mode_bits:		Mode bits of SPI master.
@@ -26,4 +29,22 @@ struct altera_spi_platform_data {
 	struct spi_board_info		*devices;
 };
 
+struct altera_spi {
+	int irq;
+	int len;
+	int count;
+	int bytes_per_word;
+	u32 imr;
+
+	/* data buffers */
+	const unsigned char *tx;
+	unsigned char *rx;
+
+	struct regmap *regmap;
+	u32 regoff;
+	struct device *dev;
+};
+
+extern irqreturn_t altera_spi_irq(int irq, void *dev);
+extern void altera_spi_init_master(struct spi_master *master);
 #endif /* __LINUX_SPI_ALTERA_H */