diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index e2be7da..848e03e 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -1,19 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * OMAP2 McSPI controller driver
  *
  * Copyright (C) 2005, 2006 Nokia Corporation
  * Author:	Samuel Ortiz <samuel.ortiz@nokia.com> and
  *		Juha Yrj�l� <juha.yrjola@nokia.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
  */
 
 #include <linux/kernel.h>
@@ -33,6 +24,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/gcd.h>
+#include <linux/iopoll.h>
 
 #include <linux/spi/spi.h>
 #include <linux/gpio.h>
@@ -126,6 +118,7 @@
 };
 
 struct omap2_mcspi {
+	struct completion	txdone;
 	struct spi_master	*master;
 	/* Virtual base address of the controller */
 	void __iomem		*base;
@@ -135,6 +128,7 @@
 	struct device		*dev;
 	struct omap2_mcspi_regs ctx;
 	int			fifo_depth;
+	bool			slave_aborted;
 	unsigned int		pin_dir:1;
 };
 
@@ -274,19 +268,23 @@
 	}
 }
 
-static void omap2_mcspi_set_master_mode(struct spi_master *master)
+static void omap2_mcspi_set_mode(struct spi_master *master)
 {
 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
 	u32 l;
 
 	/*
-	 * Setup when switching from (reset default) slave mode
-	 * to single-channel master mode
+	 * Choose master or slave mode
 	 */
 	l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
-	l &= ~(OMAP2_MCSPI_MODULCTRL_STEST | OMAP2_MCSPI_MODULCTRL_MS);
-	l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
+	l &= ~(OMAP2_MCSPI_MODULCTRL_STEST);
+	if (spi_controller_is_slave(master)) {
+		l |= (OMAP2_MCSPI_MODULCTRL_MS);
+	} else {
+		l &= ~(OMAP2_MCSPI_MODULCTRL_MS);
+		l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
+	}
 	mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
 
 	ctx->modulctrl = l;
@@ -299,7 +297,7 @@
 	struct omap2_mcspi_cs *cs = spi->controller_state;
 	struct omap2_mcspi *mcspi;
 	unsigned int wcnt;
-	int max_fifo_depth, fifo_depth, bytes_per_word;
+	int max_fifo_depth, bytes_per_word;
 	u32 chconf, xferlevel;
 
 	mcspi = spi_master_get_devdata(master);
@@ -315,10 +313,6 @@
 		else
 			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
 
-		fifo_depth = gcd(t->len, max_fifo_depth);
-		if (fifo_depth < 2 || fifo_depth % bytes_per_word != 0)
-			goto disable_fifo;
-
 		wcnt = t->len / bytes_per_word;
 		if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
 			goto disable_fifo;
@@ -326,16 +320,17 @@
 		xferlevel = wcnt << 16;
 		if (t->rx_buf != NULL) {
 			chconf |= OMAP2_MCSPI_CHCONF_FFER;
-			xferlevel |= (fifo_depth - 1) << 8;
+			xferlevel |= (bytes_per_word - 1) << 8;
 		}
+
 		if (t->tx_buf != NULL) {
 			chconf |= OMAP2_MCSPI_CHCONF_FFET;
-			xferlevel |= fifo_depth - 1;
+			xferlevel |= bytes_per_word - 1;
 		}
 
 		mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel);
 		mcspi_write_chconf0(spi, chconf);
-		mcspi->fifo_depth = fifo_depth;
+		mcspi->fifo_depth = max_fifo_depth;
 
 		return;
 	}
@@ -353,18 +348,22 @@
 
 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
 {
-	unsigned long timeout;
+	u32 val;
 
-	timeout = jiffies + msecs_to_jiffies(1000);
-	while (!(readl_relaxed(reg) & bit)) {
-		if (time_after(jiffies, timeout)) {
-			if (!(readl_relaxed(reg) & bit))
-				return -ETIMEDOUT;
-			else
-				return 0;
-		}
-		cpu_relax();
+	return readl_poll_timeout(reg, val, val & bit, 1, MSEC_PER_SEC);
+}
+
+static int mcspi_wait_for_completion(struct  omap2_mcspi *mcspi,
+				     struct completion *x)
+{
+	if (spi_controller_is_slave(mcspi->master)) {
+		if (wait_for_completion_interruptible(x) ||
+		    mcspi->slave_aborted)
+			return -EINTR;
+	} else {
+		wait_for_completion(x);
 	}
+
 	return 0;
 }
 
@@ -517,7 +516,12 @@
 	dma_async_issue_pending(mcspi_dma->dma_rx);
 	omap2_mcspi_set_dma_req(spi, 1, 1);
 
-	wait_for_completion(&mcspi_dma->dma_rx_completion);
+	ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_rx_completion);
+	if (ret || mcspi->slave_aborted) {
+		dmaengine_terminate_sync(mcspi_dma->dma_rx);
+		omap2_mcspi_set_dma_req(spi, 1, 0);
+		return 0;
+	}
 
 	for (x = 0; x < nb_sizes; x++)
 		kfree(sg_out[x]);
@@ -585,7 +589,6 @@
 	struct dma_slave_config	cfg;
 	enum dma_slave_buswidth width;
 	unsigned es;
-	u32			burst;
 	void __iomem		*chstat_reg;
 	void __iomem            *irqstat_reg;
 	int			wait_res;
@@ -605,34 +608,49 @@
 	}
 
 	count = xfer->len;
-	burst = 1;
-
-	if (mcspi->fifo_depth > 0) {
-		if (count > mcspi->fifo_depth)
-			burst = mcspi->fifo_depth / es;
-		else
-			burst = count / es;
-	}
 
 	memset(&cfg, 0, sizeof(cfg));
 	cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
 	cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
 	cfg.src_addr_width = width;
 	cfg.dst_addr_width = width;
-	cfg.src_maxburst = burst;
-	cfg.dst_maxburst = burst;
+	cfg.src_maxburst = 1;
+	cfg.dst_maxburst = 1;
 
 	rx = xfer->rx_buf;
 	tx = xfer->tx_buf;
 
-	if (tx != NULL)
+	mcspi->slave_aborted = false;
+	reinit_completion(&mcspi_dma->dma_tx_completion);
+	reinit_completion(&mcspi_dma->dma_rx_completion);
+	reinit_completion(&mcspi->txdone);
+	if (tx) {
+		/* Enable EOW IRQ to know end of tx in slave mode */
+		if (spi_controller_is_slave(spi->master))
+			mcspi_write_reg(spi->master,
+					OMAP2_MCSPI_IRQENABLE,
+					OMAP2_MCSPI_IRQSTATUS_EOW);
 		omap2_mcspi_tx_dma(spi, xfer, cfg);
+	}
 
 	if (rx != NULL)
 		count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
 
 	if (tx != NULL) {
-		wait_for_completion(&mcspi_dma->dma_tx_completion);
+		int ret;
+
+		ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_tx_completion);
+		if (ret || mcspi->slave_aborted) {
+			dmaengine_terminate_sync(mcspi_dma->dma_tx);
+			omap2_mcspi_set_dma_req(spi, 0, 0);
+			return 0;
+		}
+
+		if (spi_controller_is_slave(mcspi->master)) {
+			ret = mcspi_wait_for_completion(mcspi, &mcspi->txdone);
+			if (ret || mcspi->slave_aborted)
+				return 0;
+		}
 
 		if (mcspi->fifo_depth > 0) {
 			irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
@@ -1089,6 +1107,36 @@
 		gpio_free(spi->cs_gpio);
 }
 
+static irqreturn_t omap2_mcspi_irq_handler(int irq, void *data)
+{
+	struct omap2_mcspi *mcspi = data;
+	u32 irqstat;
+
+	irqstat	= mcspi_read_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS);
+	if (!irqstat)
+		return IRQ_NONE;
+
+	/* Disable IRQ and wakeup slave xfer task */
+	mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQENABLE, 0);
+	if (irqstat & OMAP2_MCSPI_IRQSTATUS_EOW)
+		complete(&mcspi->txdone);
+
+	return IRQ_HANDLED;
+}
+
+static int omap2_mcspi_slave_abort(struct spi_master *master)
+{
+	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
+	struct omap2_mcspi_dma *mcspi_dma = mcspi->dma_channels;
+
+	mcspi->slave_aborted = true;
+	complete(&mcspi_dma->dma_rx_completion);
+	complete(&mcspi_dma->dma_tx_completion);
+	complete(&mcspi->txdone);
+
+	return 0;
+}
+
 static int omap2_mcspi_transfer_one(struct spi_master *master,
 				    struct spi_device *spi,
 				    struct spi_transfer *t)
@@ -1255,10 +1303,20 @@
 				struct spi_device *spi,
 				struct spi_transfer *xfer)
 {
+	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
+	struct omap2_mcspi_dma *mcspi_dma =
+		&mcspi->dma_channels[spi->chip_select];
+
+	if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx)
+		return false;
+
+	if (spi_controller_is_slave(master))
+		return true;
+
 	return (xfer->len >= DMA_MIN_BYTES);
 }
 
-static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
+static int omap2_mcspi_controller_setup(struct omap2_mcspi *mcspi)
 {
 	struct spi_master	*master = mcspi->master;
 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
@@ -1275,7 +1333,7 @@
 			OMAP2_MCSPI_WAKEUPENABLE_WKEN);
 	ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
 
-	omap2_mcspi_set_master_mode(master);
+	omap2_mcspi_set_mode(master);
 	pm_runtime_mark_last_busy(mcspi->dev);
 	pm_runtime_put_autosuspend(mcspi->dev);
 	return 0;
@@ -1350,11 +1408,12 @@
 	struct device_node	*node = pdev->dev.of_node;
 	const struct of_device_id *match;
 
-	master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
-	if (master == NULL) {
-		dev_dbg(&pdev->dev, "master allocation failed\n");
+	if (of_property_read_bool(node, "spi-slave"))
+		master = spi_alloc_slave(&pdev->dev, sizeof(*mcspi));
+	else
+		master = spi_alloc_master(&pdev->dev, sizeof(*mcspi));
+	if (!master)
 		return -ENOMEM;
-	}
 
 	/* the spi->mode bits understood by this driver: */
 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
@@ -1366,6 +1425,7 @@
 	master->transfer_one = omap2_mcspi_transfer_one;
 	master->set_cs = omap2_mcspi_set_cs;
 	master->cleanup = omap2_mcspi_cleanup;
+	master->slave_abort = omap2_mcspi_slave_abort;
 	master->dev.of_node = node;
 	master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
 	master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
@@ -1417,15 +1477,31 @@
 		sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i);
 	}
 
+	status = platform_get_irq(pdev, 0);
+	if (status == -EPROBE_DEFER)
+		goto free_master;
+	if (status < 0) {
+		dev_err(&pdev->dev, "no irq resource found\n");
+		goto free_master;
+	}
+	init_completion(&mcspi->txdone);
+	status = devm_request_irq(&pdev->dev, status,
+				  omap2_mcspi_irq_handler, 0, pdev->name,
+				  mcspi);
+	if (status) {
+		dev_err(&pdev->dev, "Cannot request IRQ");
+		goto free_master;
+	}
+
 	pm_runtime_use_autosuspend(&pdev->dev);
 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
 	pm_runtime_enable(&pdev->dev);
 
-	status = omap2_mcspi_master_setup(mcspi);
+	status = omap2_mcspi_controller_setup(mcspi);
 	if (status < 0)
 		goto disable_pm;
 
-	status = devm_spi_register_master(&pdev->dev, master);
+	status = devm_spi_register_controller(&pdev->dev, master);
 	if (status < 0)
 		goto disable_pm;