1 files changed, 332 insertions, 187 deletions

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index b96e55f59d1a..9ace259d2d29 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -6,12 +6,14 @@
  */
 
 #include <linux/clk.h>
+#include <linux/idr.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/spi/spi.h>
+#include <linux/timer.h>
 
 #define SPI_ENGINE_VERSION_MAJOR(x)	((x >> 16) & 0xff)
 #define SPI_ENGINE_VERSION_MINOR(x)	((x >> 8) & 0xff)
@@ -52,6 +54,7 @@
 
 #define SPI_ENGINE_CMD_REG_CLK_DIV		0x0
 #define SPI_ENGINE_CMD_REG_CONFIG		0x1
+#define SPI_ENGINE_CMD_REG_XFER_BITS		0x2
 
 #define SPI_ENGINE_MISC_SYNC			0x0
 #define SPI_ENGINE_MISC_SLEEP			0x1
@@ -78,29 +81,42 @@ struct spi_engine_program {
 	uint16_t instructions[];
 };
 
-struct spi_engine {
-	struct clk *clk;
-	struct clk *ref_clk;
-
-	spinlock_t lock;
-
-	void __iomem *base;
-
-	struct spi_message *msg;
+/**
+ * struct spi_engine_message_state - SPI engine per-message state
+ */
+struct spi_engine_message_state {
+	/** @p: Instructions for executing this message. */
 	struct spi_engine_program *p;
+	/** @cmd_length: Number of elements in cmd_buf array. */
 	unsigned cmd_length;
+	/** @cmd_buf: Array of commands not yet written to CMD FIFO. */
 	const uint16_t *cmd_buf;
-
+	/** @tx_xfer: Next xfer with tx_buf not yet fully written to TX FIFO. */
 	struct spi_transfer *tx_xfer;
+	/** @tx_length: Size of tx_buf in bytes. */
 	unsigned int tx_length;
+	/** @tx_buf: Bytes not yet written to TX FIFO. */
 	const uint8_t *tx_buf;
-
+	/** @rx_xfer: Next xfer with rx_buf not yet fully written to RX FIFO. */
 	struct spi_transfer *rx_xfer;
+	/** @rx_length: Size of tx_buf in bytes. */
 	unsigned int rx_length;
+	/** @rx_buf: Bytes not yet written to the RX FIFO. */
 	uint8_t *rx_buf;
+	/** @sync_id: ID to correlate SYNC interrupts with this message. */
+	u8 sync_id;
+};
+
+struct spi_engine {
+	struct clk *clk;
+	struct clk *ref_clk;
+
+	spinlock_t lock;
 
-	unsigned int sync_id;
-	unsigned int completed_id;
+	void __iomem *base;
+	struct ida sync_ida;
+	struct timer_list watchdog_timer;
+	struct spi_controller *controller;
 
 	unsigned int int_enable;
 };
@@ -127,25 +143,17 @@ static unsigned int spi_engine_get_config(struct spi_device *spi)
 	return config;
 }
 
-static unsigned int spi_engine_get_clk_div(struct spi_engine *spi_engine,
-	struct spi_device *spi, struct spi_transfer *xfer)
-{
-	unsigned int clk_div;
-
-	clk_div = DIV_ROUND_UP(clk_get_rate(spi_engine->ref_clk),
-		xfer->speed_hz * 2);
-	if (clk_div > 255)
-		clk_div = 255;
-	else if (clk_div > 0)
-		clk_div -= 1;
-
-	return clk_div;
-}
-
 static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry,
 	struct spi_transfer *xfer)
 {
-	unsigned int len = xfer->len;
+	unsigned int len;
+
+	if (xfer->bits_per_word <= 8)
+		len = xfer->len;
+	else if (xfer->bits_per_word <= 16)
+		len = xfer->len / 2;
+	else
+		len = xfer->len / 4;
 
 	while (len) {
 		unsigned int n = min(len, 256U);
@@ -163,22 +171,16 @@ static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry,
 }
 
 static void spi_engine_gen_sleep(struct spi_engine_program *p, bool dry,
-	struct spi_engine *spi_engine, unsigned int clk_div,
-	struct spi_transfer *xfer)
+				 int delay_ns, u32 sclk_hz)
 {
-	unsigned int spi_clk = clk_get_rate(spi_engine->ref_clk);
 	unsigned int t;
-	int delay;
 
-	delay = spi_delay_to_ns(&xfer->delay, xfer);
-	if (delay < 0)
+	/* negative delay indicates error, e.g. from spi_delay_to_ns() */
+	if (delay_ns <= 0)
 		return;
-	delay /= 1000;
 
-	if (delay == 0)
-		return;
-
-	t = DIV_ROUND_UP(delay * spi_clk, (clk_div + 1) * 2);
+	/* rounding down since executing the instruction adds a couple of ticks delay */
+	t = DIV_ROUND_DOWN_ULL((u64)delay_ns * sclk_hz, NSEC_PER_SEC);
 	while (t) {
 		unsigned int n = min(t, 256U);
 
@@ -195,53 +197,105 @@ static void spi_engine_gen_cs(struct spi_engine_program *p, bool dry,
 	if (assert)
 		mask ^= BIT(spi_get_chipselect(spi, 0));
 
-	spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_ASSERT(1, mask));
+	spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_ASSERT(0, mask));
+}
+
+/*
+ * Performs precompile steps on the message.
+ *
+ * The SPI core does most of the message/transfer validation and filling in
+ * fields for us via __spi_validate(). This fixes up anything remaining not
+ * done there.
+ *
+ * NB: This is separate from spi_engine_compile_message() because the latter
+ * is called twice and would otherwise result in double-evaluation.
+ */
+static void spi_engine_precompile_message(struct spi_message *msg)
+{
+	unsigned int clk_div, max_hz = msg->spi->controller->max_speed_hz;
+	struct spi_transfer *xfer;
+
+	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+		clk_div = DIV_ROUND_UP(max_hz, xfer->speed_hz);
+		xfer->effective_speed_hz = max_hz / min(clk_div, 256U);
+	}
 }
 
-static int spi_engine_compile_message(struct spi_engine *spi_engine,
-	struct spi_message *msg, bool dry, struct spi_engine_program *p)
+static void spi_engine_compile_message(struct spi_message *msg, bool dry,
+				       struct spi_engine_program *p)
 {
 	struct spi_device *spi = msg->spi;
+	struct spi_controller *host = spi->controller;
 	struct spi_transfer *xfer;
 	int clk_div, new_clk_div;
-	bool cs_change = true;
+	bool keep_cs = false;
+	u8 bits_per_word = 0;
 
-	clk_div = -1;
+	clk_div = 1;
 
 	spi_engine_program_add_cmd(p, dry,
 		SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CONFIG,
 			spi_engine_get_config(spi)));
 
+	xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list);
+	spi_engine_gen_cs(p, dry, spi, !xfer->cs_off);
+
 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
-		new_clk_div = spi_engine_get_clk_div(spi_engine, spi, xfer);
+		new_clk_div = host->max_speed_hz / xfer->effective_speed_hz;
 		if (new_clk_div != clk_div) {
 			clk_div = new_clk_div;
+			/* actual divider used is register value + 1 */
 			spi_engine_program_add_cmd(p, dry,
 				SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CLK_DIV,
-					clk_div));
+					clk_div - 1));
 		}
 
-		if (cs_change)
-			spi_engine_gen_cs(p, dry, spi, true);
+		if (bits_per_word != xfer->bits_per_word) {
+			bits_per_word = xfer->bits_per_word;
+			spi_engine_program_add_cmd(p, dry,
+				SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_XFER_BITS,
+					bits_per_word));
+		}
 
 		spi_engine_gen_xfer(p, dry, xfer);
-		spi_engine_gen_sleep(p, dry, spi_engine, clk_div, xfer);
-
-		cs_change = xfer->cs_change;
-		if (list_is_last(&xfer->transfer_list, &msg->transfers))
-			cs_change = !cs_change;
-
-		if (cs_change)
-			spi_engine_gen_cs(p, dry, spi, false);
+		spi_engine_gen_sleep(p, dry, spi_delay_to_ns(&xfer->delay, xfer),
+				     xfer->effective_speed_hz);
+
+		if (xfer->cs_change) {
+			if (list_is_last(&xfer->transfer_list, &msg->transfers)) {
+				keep_cs = true;
+			} else {
+				if (!xfer->cs_off)
+					spi_engine_gen_cs(p, dry, spi, false);
+
+				spi_engine_gen_sleep(p, dry, spi_delay_to_ns(
+					&xfer->cs_change_delay, xfer),
+					xfer->effective_speed_hz);
+
+				if (!list_next_entry(xfer, transfer_list)->cs_off)
+					spi_engine_gen_cs(p, dry, spi, true);
+			}
+		} else if (!list_is_last(&xfer->transfer_list, &msg->transfers) &&
+			   xfer->cs_off != list_next_entry(xfer, transfer_list)->cs_off) {
+			spi_engine_gen_cs(p, dry, spi, xfer->cs_off);
+		}
 	}
 
-	return 0;
+	if (!keep_cs)
+		spi_engine_gen_cs(p, dry, spi, false);
+
+	/*
+	 * Restore clockdiv to default so that future gen_sleep commands don't
+	 * have to be aware of the current register state.
+	 */
+	if (clk_div != 1)
+		spi_engine_program_add_cmd(p, dry,
+			SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CLK_DIV, 0));
 }
 
-static void spi_engine_xfer_next(struct spi_engine *spi_engine,
+static void spi_engine_xfer_next(struct spi_message *msg,
 	struct spi_transfer **_xfer)
 {
-	struct spi_message *msg = spi_engine->msg;
 	struct spi_transfer *xfer = *_xfer;
 
 	if (!xfer) {
@@ -256,147 +310,192 @@ static void spi_engine_xfer_next(struct spi_engine *spi_engine,
 	*_xfer = xfer;
 }
 
-static void spi_engine_tx_next(struct spi_engine *spi_engine)
+static void spi_engine_tx_next(struct spi_message *msg)
 {
-	struct spi_transfer *xfer = spi_engine->tx_xfer;
+	struct spi_engine_message_state *st = msg->state;
+	struct spi_transfer *xfer = st->tx_xfer;
 
 	do {
-		spi_engine_xfer_next(spi_engine, &xfer);
+		spi_engine_xfer_next(msg, &xfer);
 	} while (xfer && !xfer->tx_buf);
 
-	spi_engine->tx_xfer = xfer;
+	st->tx_xfer = xfer;
 	if (xfer) {
-		spi_engine->tx_length = xfer->len;
-		spi_engine->tx_buf = xfer->tx_buf;
+		st->tx_length = xfer->len;
+		st->tx_buf = xfer->tx_buf;
 	} else {
-		spi_engine->tx_buf = NULL;
+		st->tx_buf = NULL;
 	}
 }
 
-static void spi_engine_rx_next(struct spi_engine *spi_engine)
+static void spi_engine_rx_next(struct spi_message *msg)
 {
-	struct spi_transfer *xfer = spi_engine->rx_xfer;
+	struct spi_engine_message_state *st = msg->state;
+	struct spi_transfer *xfer = st->rx_xfer;
 
 	do {
-		spi_engine_xfer_next(spi_engine, &xfer);
+		spi_engine_xfer_next(msg, &xfer);
 	} while (xfer && !xfer->rx_buf);
 
-	spi_engine->rx_xfer = xfer;
+	st->rx_xfer = xfer;
 	if (xfer) {
-		spi_engine->rx_length = xfer->len;
-		spi_engine->rx_buf = xfer->rx_buf;
+		st->rx_length = xfer->len;
+		st->rx_buf = xfer->rx_buf;
 	} else {
-		spi_engine->rx_buf = NULL;
+		st->rx_buf = NULL;
 	}
 }
 
-static bool spi_engine_write_cmd_fifo(struct spi_engine *spi_engine)
+static bool spi_engine_write_cmd_fifo(struct spi_engine *spi_engine,
+				      struct spi_message *msg)
 {
 	void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_CMD_FIFO;
+	struct spi_engine_message_state *st = msg->state;
 	unsigned int n, m, i;
 	const uint16_t *buf;
 
 	n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_CMD_FIFO_ROOM);
-	while (n && spi_engine->cmd_length) {
-		m = min(n, spi_engine->cmd_length);
-		buf = spi_engine->cmd_buf;
+	while (n && st->cmd_length) {
+		m = min(n, st->cmd_length);
+		buf = st->cmd_buf;
 		for (i = 0; i < m; i++)
 			writel_relaxed(buf[i], addr);
-		spi_engine->cmd_buf += m;
-		spi_engine->cmd_length -= m;
+		st->cmd_buf += m;
+		st->cmd_length -= m;
 		n -= m;
 	}
 
-	return spi_engine->cmd_length != 0;
+	return st->cmd_length != 0;
 }
 
-static bool spi_engine_write_tx_fifo(struct spi_engine *spi_engine)
+static bool spi_engine_write_tx_fifo(struct spi_engine *spi_engine,
+				     struct spi_message *msg)
 {
 	void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_SDO_DATA_FIFO;
+	struct spi_engine_message_state *st = msg->state;
 	unsigned int n, m, i;
-	const uint8_t *buf;
 
 	n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_SDO_FIFO_ROOM);
-	while (n && spi_engine->tx_length) {
-		m = min(n, spi_engine->tx_length);
-		buf = spi_engine->tx_buf;
-		for (i = 0; i < m; i++)
-			writel_relaxed(buf[i], addr);
-		spi_engine->tx_buf += m;
-		spi_engine->tx_length -= m;
+	while (n && st->tx_length) {
+		if (st->tx_xfer->bits_per_word <= 8) {
+			const u8 *buf = st->tx_buf;
+
+			m = min(n, st->tx_length);
+			for (i = 0; i < m; i++)
+				writel_relaxed(buf[i], addr);
+			st->tx_buf += m;
+			st->tx_length -= m;
+		} else if (st->tx_xfer->bits_per_word <= 16) {
+			const u16 *buf = (const u16 *)st->tx_buf;
+
+			m = min(n, st->tx_length / 2);
+			for (i = 0; i < m; i++)
+				writel_relaxed(buf[i], addr);
+			st->tx_buf += m * 2;
+			st->tx_length -= m * 2;
+		} else {
+			const u32 *buf = (const u32 *)st->tx_buf;
+
+			m = min(n, st->tx_length / 4);
+			for (i = 0; i < m; i++)
+				writel_relaxed(buf[i], addr);
+			st->tx_buf += m * 4;
+			st->tx_length -= m * 4;
+		}
 		n -= m;
-		if (spi_engine->tx_length == 0)
-			spi_engine_tx_next(spi_engine);
+		if (st->tx_length == 0)
+			spi_engine_tx_next(msg);
 	}
 
-	return spi_engine->tx_length != 0;
+	return st->tx_length != 0;
 }
 
-static bool spi_engine_read_rx_fifo(struct spi_engine *spi_engine)
+static bool spi_engine_read_rx_fifo(struct spi_engine *spi_engine,
+				    struct spi_message *msg)
 {
 	void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_SDI_DATA_FIFO;
+	struct spi_engine_message_state *st = msg->state;
 	unsigned int n, m, i;
-	uint8_t *buf;
 
 	n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_SDI_FIFO_LEVEL);
-	while (n && spi_engine->rx_length) {
-		m = min(n, spi_engine->rx_length);
-		buf = spi_engine->rx_buf;
-		for (i = 0; i < m; i++)
-			buf[i] = readl_relaxed(addr);
-		spi_engine->rx_buf += m;
-		spi_engine->rx_length -= m;
+	while (n && st->rx_length) {
+		if (st->rx_xfer->bits_per_word <= 8) {
+			u8 *buf = st->rx_buf;
+
+			m = min(n, st->rx_length);
+			for (i = 0; i < m; i++)
+				buf[i] = readl_relaxed(addr);
+			st->rx_buf += m;
+			st->rx_length -= m;
+		} else if (st->rx_xfer->bits_per_word <= 16) {
+			u16 *buf = (u16 *)st->rx_buf;
+
+			m = min(n, st->rx_length / 2);
+			for (i = 0; i < m; i++)
+				buf[i] = readl_relaxed(addr);
+			st->rx_buf += m * 2;
+			st->rx_length -= m * 2;
+		} else {
+			u32 *buf = (u32 *)st->rx_buf;
+
+			m = min(n, st->rx_length / 4);
+			for (i = 0; i < m; i++)
+				buf[i] = readl_relaxed(addr);
+			st->rx_buf += m * 4;
+			st->rx_length -= m * 4;
+		}
 		n -= m;
-		if (spi_engine->rx_length == 0)
-			spi_engine_rx_next(spi_engine);
+		if (st->rx_length == 0)
+			spi_engine_rx_next(msg);
 	}
 
-	return spi_engine->rx_length != 0;
+	return st->rx_length != 0;
 }
 
 static irqreturn_t spi_engine_irq(int irq, void *devid)
 {
 	struct spi_controller *host = devid;
+	struct spi_message *msg = host->cur_msg;
 	struct spi_engine *spi_engine = spi_controller_get_devdata(host);
 	unsigned int disable_int = 0;
 	unsigned int pending;
+	int completed_id = -1;
 
 	pending = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
 
 	if (pending & SPI_ENGINE_INT_SYNC) {
 		writel_relaxed(SPI_ENGINE_INT_SYNC,
 			spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
-		spi_engine->completed_id = readl_relaxed(
+		completed_id = readl_relaxed(
 			spi_engine->base + SPI_ENGINE_REG_SYNC_ID);
 	}
 
 	spin_lock(&spi_engine->lock);
 
 	if (pending & SPI_ENGINE_INT_CMD_ALMOST_EMPTY) {
-		if (!spi_engine_write_cmd_fifo(spi_engine))
+		if (!spi_engine_write_cmd_fifo(spi_engine, msg))
 			disable_int |= SPI_ENGINE_INT_CMD_ALMOST_EMPTY;
 	}
 
 	if (pending & SPI_ENGINE_INT_SDO_ALMOST_EMPTY) {
-		if (!spi_engine_write_tx_fifo(spi_engine))
+		if (!spi_engine_write_tx_fifo(spi_engine, msg))
 			disable_int |= SPI_ENGINE_INT_SDO_ALMOST_EMPTY;
 	}
 
 	if (pending & (SPI_ENGINE_INT_SDI_ALMOST_FULL | SPI_ENGINE_INT_SYNC)) {
-		if (!spi_engine_read_rx_fifo(spi_engine))
+		if (!spi_engine_read_rx_fifo(spi_engine, msg))
 			disable_int |= SPI_ENGINE_INT_SDI_ALMOST_FULL;
 	}
 
-	if (pending & SPI_ENGINE_INT_SYNC) {
-		if (spi_engine->msg &&
-		    spi_engine->completed_id == spi_engine->sync_id) {
-			struct spi_message *msg = spi_engine->msg;
-
-			kfree(spi_engine->p);
-			msg->status = 0;
-			msg->actual_length = msg->frame_length;
-			spi_engine->msg = NULL;
-			spi_finalize_current_message(host);
+	if (pending & SPI_ENGINE_INT_SYNC && msg) {
+		struct spi_engine_message_state *st = msg->state;
+
+		if (completed_id == st->sync_id) {
+			if (timer_delete_sync(&spi_engine->watchdog_timer)) {
+				msg->status = 0;
+				msg->actual_length = msg->frame_length;
+				spi_finalize_current_message(host);
+			}
 			disable_int |= SPI_ENGINE_INT_SYNC;
 		}
 	}
@@ -412,43 +511,86 @@ static irqreturn_t spi_engine_irq(int irq, void *devid)
 	return IRQ_HANDLED;
 }
 
-static int spi_engine_transfer_one_message(struct spi_controller *host,
-	struct spi_message *msg)
+static int spi_engine_prepare_message(struct spi_controller *host,
+				      struct spi_message *msg)
 {
 	struct spi_engine_program p_dry, *p;
 	struct spi_engine *spi_engine = spi_controller_get_devdata(host);
-	unsigned int int_enable = 0;
-	unsigned long flags;
+	struct spi_engine_message_state *st;
 	size_t size;
+	int ret;
+
+	st = kzalloc(sizeof(*st), GFP_KERNEL);
+	if (!st)
+		return -ENOMEM;
+
+	spi_engine_precompile_message(msg);
 
 	p_dry.length = 0;
-	spi_engine_compile_message(spi_engine, msg, true, &p_dry);
+	spi_engine_compile_message(msg, true, &p_dry);
 
 	size = sizeof(*p->instructions) * (p_dry.length + 1);
 	p = kzalloc(sizeof(*p) + size, GFP_KERNEL);
-	if (!p)
+	if (!p) {
+		kfree(st);
 		return -ENOMEM;
-	spi_engine_compile_message(spi_engine, msg, false, p);
+	}
 
-	spin_lock_irqsave(&spi_engine->lock, flags);
-	spi_engine->sync_id = (spi_engine->sync_id + 1) & 0xff;
-	spi_engine_program_add_cmd(p, false,
-		SPI_ENGINE_CMD_SYNC(spi_engine->sync_id));
+	ret = ida_alloc_range(&spi_engine->sync_ida, 0, U8_MAX, GFP_KERNEL);
+	if (ret < 0) {
+		kfree(p);
+		kfree(st);
+		return ret;
+	}
+
+	st->sync_id = ret;
+
+	spi_engine_compile_message(msg, false, p);
+
+	spi_engine_program_add_cmd(p, false, SPI_ENGINE_CMD_SYNC(st->sync_id));
+
+	st->p = p;
+	st->cmd_buf = p->instructions;
+	st->cmd_length = p->length;
+	msg->state = st;
+
+	return 0;
+}
+
+static int spi_engine_unprepare_message(struct spi_controller *host,
+					struct spi_message *msg)
+{
+	struct spi_engine *spi_engine = spi_controller_get_devdata(host);
+	struct spi_engine_message_state *st = msg->state;
+
+	ida_free(&spi_engine->sync_ida, st->sync_id);
+	kfree(st->p);
+	kfree(st);
 
-	spi_engine->msg = msg;
-	spi_engine->p = p;
+	return 0;
+}
 
-	spi_engine->cmd_buf = p->instructions;
-	spi_engine->cmd_length = p->length;
-	if (spi_engine_write_cmd_fifo(spi_engine))
+static int spi_engine_transfer_one_message(struct spi_controller *host,
+	struct spi_message *msg)
+{
+	struct spi_engine *spi_engine = spi_controller_get_devdata(host);
+	struct spi_engine_message_state *st = msg->state;
+	unsigned int int_enable = 0;
+	unsigned long flags;
+
+	mod_timer(&spi_engine->watchdog_timer, jiffies + msecs_to_jiffies(5000));
+
+	spin_lock_irqsave(&spi_engine->lock, flags);
+
+	if (spi_engine_write_cmd_fifo(spi_engine, msg))
 		int_enable |= SPI_ENGINE_INT_CMD_ALMOST_EMPTY;
 
-	spi_engine_tx_next(spi_engine);
-	if (spi_engine_write_tx_fifo(spi_engine))
+	spi_engine_tx_next(msg);
+	if (spi_engine_write_tx_fifo(spi_engine, msg))
 		int_enable |= SPI_ENGINE_INT_SDO_ALMOST_EMPTY;
 
-	spi_engine_rx_next(spi_engine);
-	if (spi_engine->rx_length != 0)
+	spi_engine_rx_next(msg);
+	if (st->rx_length != 0)
 		int_enable |= SPI_ENGINE_INT_SDI_ALMOST_FULL;
 
 	int_enable |= SPI_ENGINE_INT_SYNC;
@@ -461,6 +603,29 @@ static int spi_engine_transfer_one_message(struct spi_controller *host,
 	return 0;
 }
 
+static void spi_engine_timeout(struct timer_list *timer)
+{
+	struct spi_engine *spi_engine = from_timer(spi_engine, timer, watchdog_timer);
+	struct spi_controller *host = spi_engine->controller;
+
+	if (WARN_ON(!host->cur_msg))
+		return;
+
+	dev_err(&host->dev,
+		"Timeout occurred while waiting for transfer to complete. Hardware is probably broken.\n");
+	host->cur_msg->status = -ETIMEDOUT;
+	spi_finalize_current_message(host);
+}
+
+static void spi_engine_release_hw(void *p)
+{
+	struct spi_engine *spi_engine = p;
+
+	writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
+	writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
+	writel_relaxed(0x01, spi_engine->base + SPI_ENGINE_REG_RESET);
+}
+
 static int spi_engine_probe(struct platform_device *pdev)
 {
 	struct spi_engine *spi_engine;
@@ -473,35 +638,28 @@ static int spi_engine_probe(struct platform_device *pdev)
 	if (irq < 0)
 		return irq;
 
-	spi_engine = devm_kzalloc(&pdev->dev, sizeof(*spi_engine), GFP_KERNEL);
-	if (!spi_engine)
-		return -ENOMEM;
-
-	host = spi_alloc_host(&pdev->dev, 0);
+	host = devm_spi_alloc_host(&pdev->dev, sizeof(*spi_engine));
 	if (!host)
 		return -ENOMEM;
 
-	spi_controller_set_devdata(host, spi_engine);
+	spi_engine = spi_controller_get_devdata(host);
 
 	spin_lock_init(&spi_engine->lock);
+	ida_init(&spi_engine->sync_ida);
+	timer_setup(&spi_engine->watchdog_timer, spi_engine_timeout, TIMER_IRQSAFE);
+	spi_engine->controller = host;
 
 	spi_engine->clk = devm_clk_get_enabled(&pdev->dev, "s_axi_aclk");
-	if (IS_ERR(spi_engine->clk)) {
-		ret = PTR_ERR(spi_engine->clk);
-		goto err_put_host;
-	}
+	if (IS_ERR(spi_engine->clk))
+		return PTR_ERR(spi_engine->clk);
 
 	spi_engine->ref_clk = devm_clk_get_enabled(&pdev->dev, "spi_clk");
-	if (IS_ERR(spi_engine->ref_clk)) {
-		ret = PTR_ERR(spi_engine->ref_clk);
-		goto err_put_host;
-	}
+	if (IS_ERR(spi_engine->ref_clk))
+		return PTR_ERR(spi_engine->ref_clk);
 
 	spi_engine->base = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(spi_engine->base)) {
-		ret = PTR_ERR(spi_engine->base);
-		goto err_put_host;
-	}
+	if (IS_ERR(spi_engine->base))
+		return PTR_ERR(spi_engine->base);
 
 	version = readl(spi_engine->base + SPI_ENGINE_REG_VERSION);
 	if (SPI_ENGINE_VERSION_MAJOR(version) != 1) {
@@ -509,54 +667,42 @@ static int spi_engine_probe(struct platform_device *pdev)
 			SPI_ENGINE_VERSION_MAJOR(version),
 			SPI_ENGINE_VERSION_MINOR(version),
 			SPI_ENGINE_VERSION_PATCH(version));
-		ret = -ENODEV;
-		goto err_put_host;
+		return -ENODEV;
 	}
 
 	writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_RESET);
 	writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
 	writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
 
-	ret = request_irq(irq, spi_engine_irq, 0, pdev->name, host);
+	ret = devm_add_action_or_reset(&pdev->dev, spi_engine_release_hw,
+				       spi_engine);
 	if (ret)
-		goto err_put_host;
+		return ret;
+
+	ret = devm_request_irq(&pdev->dev, irq, spi_engine_irq, 0, pdev->name,
+			       host);
+	if (ret)
+		return ret;
 
 	host->dev.of_node = pdev->dev.of_node;
 	host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_3WIRE;
-	host->bits_per_word_mask = SPI_BPW_MASK(8);
+	host->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
 	host->max_speed_hz = clk_get_rate(spi_engine->ref_clk) / 2;
 	host->transfer_one_message = spi_engine_transfer_one_message;
+	host->prepare_message = spi_engine_prepare_message;
+	host->unprepare_message = spi_engine_unprepare_message;
 	host->num_chipselect = 8;
 
-	ret = spi_register_controller(host);
+	if (host->max_speed_hz == 0)
+		return dev_err_probe(&pdev->dev, -EINVAL, "spi_clk rate is 0");
+
+	ret = devm_spi_register_controller(&pdev->dev, host);
 	if (ret)
-		goto err_free_irq;
+		return ret;
 
 	platform_set_drvdata(pdev, host);
 
 	return 0;
-err_free_irq:
-	free_irq(irq, host);
-err_put_host:
-	spi_controller_put(host);
-	return ret;
-}
-
-static void spi_engine_remove(struct platform_device *pdev)
-{
-	struct spi_controller *host = spi_controller_get(platform_get_drvdata(pdev));
-	struct spi_engine *spi_engine = spi_controller_get_devdata(host);
-	int irq = platform_get_irq(pdev, 0);
-
-	spi_unregister_controller(host);
-
-	free_irq(irq, host);
-
-	spi_controller_put(host);
-
-	writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
-	writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
-	writel_relaxed(0x01, spi_engine->base + SPI_ENGINE_REG_RESET);
 }
 
 static const struct of_device_id spi_engine_match_table[] = {
@@ -567,7 +713,6 @@ MODULE_DEVICE_TABLE(of, spi_engine_match_table);
 
 static struct platform_driver spi_engine_driver = {
 	.probe = spi_engine_probe,
-	.remove_new = spi_engine_remove,
 	.driver = {
 		.name = "spi-engine",
 		.of_match_table = spi_engine_match_table,