diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 357810d6ec2d..4e4513a2006e 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -59,6 +59,7 @@ comment "SPI Master Controller Drivers"
 
 config SPI_ALTERA
 	tristate "Altera SPI Controller"
+	select REGMAP_MMIO
 	help
 	  This is the driver for the Altera SPI Controller.
 
diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c
index aa9d1a257433..d91c0934a619 100644
--- a/drivers/spi/spi-altera.c
+++ b/drivers/spi/spi-altera.c
@@ -43,19 +43,59 @@
 
 #define ALTERA_SPI_MAX_CS		32
 
+enum altera_spi_type {
+	ALTERA_SPI_TYPE_UNKNOWN,
+	ALTERA_SPI_TYPE_SUBDEV,
+};
+
 struct altera_spi {
-	void __iomem *base;
 	int irq;
 	int len;
 	int count;
 	int bytes_per_word;
-	unsigned long imr;
+	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)
+{
+	int ret;
+
+	ret = regmap_write(hw->regmap, hw->regoff + reg, val);
+	if (ret)
+		dev_err(hw->dev, "fail to write reg 0x%x val 0x%x: %d\n",
+			reg, val, ret);
+
+	return ret;
+}
+
+static int altr_spi_readl(struct altera_spi *hw, unsigned int reg,
+			  unsigned int *val)
+{
+	int ret;
+
+	ret = regmap_read(hw->regmap, hw->regoff + reg, val);
+	if (ret)
+		dev_err(hw->dev, "fail to read reg 0x%x: %d\n", reg, ret);
+
+	return ret;
+}
+
 static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev)
 {
 	return spi_master_get_devdata(sdev->master);
@@ -67,12 +107,13 @@ static void altera_spi_set_cs(struct spi_device *spi, bool is_high)
 
 	if (is_high) {
 		hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
-		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
-		writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);
+		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
+		altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL, 0);
 	} else {
-		writel(BIT(spi->chip_select), hw->base + ALTERA_SPI_SLAVE_SEL);
+		altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL,
+				BIT(spi->chip_select));
 		hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
-		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
+		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
 	}
 }
 
@@ -99,14 +140,14 @@ static void altera_spi_tx_word(struct altera_spi *hw)
 		}
 	}
 
-	writel(txd, hw->base + ALTERA_SPI_TXDATA);
+	altr_spi_writel(hw, ALTERA_SPI_TXDATA, txd);
 }
 
 static void altera_spi_rx_word(struct altera_spi *hw)
 {
 	unsigned int rxd;
 
-	rxd = readl(hw->base + ALTERA_SPI_RXDATA);
+	altr_spi_readl(hw, ALTERA_SPI_RXDATA, &rxd);
 	if (hw->rx) {
 		switch (hw->bytes_per_word) {
 		case 1:
@@ -133,6 +174,7 @@ static int altera_spi_txrx(struct spi_master *master,
 	struct spi_device *spi, struct spi_transfer *t)
 {
 	struct altera_spi *hw = spi_master_get_devdata(master);
+	u32 val;
 
 	hw->tx = t->tx_buf;
 	hw->rx = t->rx_buf;
@@ -143,7 +185,7 @@ static int altera_spi_txrx(struct spi_master *master,
 	if (hw->irq >= 0) {
 		/* enable receive interrupt */
 		hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;
-		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
+		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
 
 		/* send the first byte */
 		altera_spi_tx_word(hw);
@@ -151,9 +193,13 @@ static int altera_spi_txrx(struct spi_master *master,
 		while (hw->count < hw->len) {
 			altera_spi_tx_word(hw);
 
-			while (!(readl(hw->base + ALTERA_SPI_STATUS) &
-				 ALTERA_SPI_STATUS_RRDY_MSK))
+			for (;;) {
+				altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
+				if (val & ALTERA_SPI_STATUS_RRDY_MSK)
+					break;
+
 				cpu_relax();
+			}
 
 			altera_spi_rx_word(hw);
 		}
@@ -175,7 +221,7 @@ static irqreturn_t altera_spi_irq(int irq, void *dev)
 	} else {
 		/* disable receive interrupt */
 		hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
-		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
+		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
 
 		spi_finalize_current_transfer(master);
 	}
@@ -185,10 +231,13 @@ static irqreturn_t altera_spi_irq(int irq, void *dev)
 
 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;
+	u32 val;
 	u16 i;
 
 	master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
@@ -220,19 +269,49 @@ static int altera_spi_probe(struct platform_device *pdev)
 	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 */
-	hw->base = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(hw->base)) {
-		err = PTR_ERR(hw->base);
-		goto exit;
+	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 */
-	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
-	writel(0, hw->base + ALTERA_SPI_STATUS);	/* clear status reg */
-	if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK)
-		readl(hw->base + ALTERA_SPI_RXDATA);	/* flush rxdata */
+	altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
+	altr_spi_writel(hw, ALTERA_SPI_STATUS, 0);	/* clear status reg */
+	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) {
@@ -255,7 +334,7 @@ static int altera_spi_probe(struct platform_device *pdev)
 		}
 	}
 
-	dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
+	dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq);
 
 	return 0;
 exit:
@@ -272,6 +351,11 @@ static const struct of_device_id altera_spi_match[] = {
 MODULE_DEVICE_TABLE(of, altera_spi_match);
 #endif /* CONFIG_OF */
 
+static const struct platform_device_id altera_spi_ids[] = {
+	{ "subdev_spi_altera", ALTERA_SPI_TYPE_SUBDEV },
+	{ }
+};
+
 static struct platform_driver altera_spi_driver = {
 	.probe = altera_spi_probe,
 	.driver = {
@@ -279,6 +363,7 @@ static struct platform_driver altera_spi_driver = {
 		.pm = NULL,
 		.of_match_table = of_match_ptr(altera_spi_match),
 	},
+	.id_table	= altera_spi_ids,
 };
 module_platform_driver(altera_spi_driver);