[PATCH 0/3] spi-bcm-qspi spcr3 enahancements

[PATCH 0/3] spi-bcm-qspi spcr3 enahancements

[Kamal Dasu]

This change set feature enahancements for spcr3 transfer modes as well as
adds support for half-duplex 3-wire mode transfer. 

Kamal Dasu (3):
  spi: bcm-qspi: Add mspi spcr3 32/64-bits xfer mode
  spi: bcm-qspi: clear MSPI spifie interrupt during probe
  spi: bcm-qspi: add support for 3-wire mode for half duplex transfer

 drivers/spi/spi-bcm-qspi.c | 262 +++++++++++++++++++++++++++++--------
 1 file changed, 208 insertions(+), 54 deletions(-)

-- 
2.17.1

[PATCH 1/3] spi: bcm-qspi: Add mspi spcr3 32/64-bits xfer mode

[Kamal Dasu]

From: Kamal Dasu <kdasu@broadcom.com>

Adding 32-bits and 64-bits per transfer modes using the SPCR3
register settings provided in MSPI controller ver >= 1.5

Signed-off-by: Kamal Dasu <kdasu@broadcom.com>
---
 drivers/spi/spi-bcm-qspi.c | 172 ++++++++++++++++++++++++++++++++-----
 1 file changed, 151 insertions(+), 21 deletions(-)

diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index a78e56f566dd..9a2d12e7650c 100644
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -83,6 +83,9 @@
 /* MSPI register offsets */
 #define MSPI_SPCR0_LSB				0x000
 #define MSPI_SPCR0_MSB				0x004
+#define MSPI_SPCR0_MSB_CPHA			BIT(0)
+#define MSPI_SPCR0_MSB_CPOL			BIT(1)
+#define MSPI_SPCR0_MSB_BITS_SHIFT		0x2
 #define MSPI_SPCR1_LSB				0x008
 #define MSPI_SPCR1_MSB				0x00c
 #define MSPI_NEWQP				0x010
@@ -102,6 +105,7 @@
 #define MSPI_NUM_CDRAM				16
 #define MSPI_CDRAM_CONT_BIT			BIT(7)
 #define MSPI_CDRAM_BITSE_BIT			BIT(6)
+#define MSPI_CDRAM_DT_BIT			BIT(5)
 #define MSPI_CDRAM_PCS				0xf
 
 #define MSPI_SPCR2_SPE				BIT(6)
@@ -114,6 +118,12 @@
 						 ~(BIT(10) | BIT(11)))
 #define MSPI_SPCR3_SYSCLKSEL_108		(MSPI_SPCR3_SYSCLKSEL_MASK & \
 						 BIT(11))
+#define MSPI_SPCR3_TXRXDAM_MASK			GENMASK(4, 2)
+#define MSPI_SPCR3_DAM_8BYTE			0
+#define MSPI_SPCR3_DAM_16BYTE			(BIT(2) | BIT(4))
+#define MSPI_SPCR3_DAM_32BYTE			(BIT(3) | BIT(5))
+#define MSPI_SPCR3_DATA_REG_SZ			BIT(8)
+#define MSPI_SPCR3_CPHARX			BIT(9)
 
 #define MSPI_MSPI_STATUS_SPIF			BIT(0)
 
@@ -153,6 +163,14 @@
 #define TRANS_STATUS_BREAK_DESELECT (TRANS_STATUS_BREAK_EOM |		\
 				     TRANS_STATUS_BREAK_CS_CHANGE)
 
+/*
+ * Used for writing and reading data in the right order
+ * to TXRAM and RXRAM when used as 32-bit registers respectively
+ */
+#define swap4bytes(__val) \
+	((((__val) >> 24) & 0x000000FF) | (((__val) >>  8) & 0x0000FF00) | \
+	 (((__val) <<  8) & 0x00FF0000) | (((__val) << 24) & 0xFF000000))
+
 struct bcm_qspi_parms {
 	u32 speed_hz;
 	u8 mode;
@@ -261,7 +279,7 @@ static inline bool bcm_qspi_has_sysclk_108(struct bcm_qspi *qspi)
 static inline int bcm_qspi_spbr_min(struct bcm_qspi *qspi)
 {
 	if (bcm_qspi_has_fastbr(qspi))
-		return 1;
+		return (bcm_qspi_has_sysclk_108(qspi) ? 4 : 1);
 	else
 		return 8;
 }
@@ -570,23 +588,23 @@ static void bcm_qspi_hw_set_parms(struct bcm_qspi *qspi,
 {
 	u32 spcr, spbr = 0;
 
-	if (xp->speed_hz)
-		spbr = qspi->base_clk / (2 * xp->speed_hz);
-
-	spcr = clamp_val(spbr, bcm_qspi_spbr_min(qspi), QSPI_SPBR_MAX);
-	bcm_qspi_write(qspi, MSPI, MSPI_SPCR0_LSB, spcr);
-
 	if (!qspi->mspi_maj_rev)
 		/* legacy controller */
 		spcr = MSPI_MASTER_BIT;
 	else
 		spcr = 0;
 
-	/* for 16 bit the data should be zero */
-	if (xp->bits_per_word != 16)
-		spcr |= xp->bits_per_word << 2;
-	spcr |= xp->mode & 3;
+	/*
+	 * Bits per transfer.  BITS determines the number of data bits
+	 * transferred if the command control bit (BITSE of a
+	 * CDRAM Register) is equal to 1.
+	 * If CDRAM BITSE is equal to 0, 8 data bits are transferred
+	 * regardless
+	 */
+	if (xp->bits_per_word != 16 && xp->bits_per_word != 64)
+		spcr |= xp->bits_per_word << MSPI_SPCR0_MSB_BITS_SHIFT;
 
+	spcr |= xp->mode & (MSPI_SPCR0_MSB_CPHA | MSPI_SPCR0_MSB_CPOL);
 	bcm_qspi_write(qspi, MSPI, MSPI_SPCR0_MSB, spcr);
 
 	if (bcm_qspi_has_fastbr(qspi)) {
@@ -599,13 +617,37 @@ static void bcm_qspi_hw_set_parms(struct bcm_qspi *qspi,
 			/* SYSCLK_108 */
 			spcr |= MSPI_SPCR3_SYSCLKSEL_108;
 			qspi->base_clk = MSPI_BASE_FREQ * 4;
-			/* Change spbr as we changed sysclk */
-			bcm_qspi_write(qspi, MSPI, MSPI_SPCR0_LSB, 4);
 		}
 
+		if (xp->bits_per_word > 16) {
+			/* data_reg_size 1 (64bit) */
+			spcr |=	MSPI_SPCR3_DATA_REG_SZ;
+			/* TxRx RAM data access mode 2 for 32B and set fastdt */
+			spcr |=	MSPI_SPCR3_DAM_32BYTE  | MSPI_SPCR3_FASTDT;
+			/*
+			 *  Set length of delay after transfer
+			 *  DTL from 0(256) to 1
+			 */
+			bcm_qspi_write(qspi, MSPI, MSPI_SPCR1_LSB, 1);
+		} else {
+			/* data_reg_size[8] = 0 */
+			spcr &=	~(MSPI_SPCR3_DATA_REG_SZ);
+
+			/*
+			 * TxRx RAM access mode 8B
+			 * and disable fastdt
+			 */
+			spcr &= ~(MSPI_SPCR3_DAM_32BYTE);
+		}
 		bcm_qspi_write(qspi, MSPI, MSPI_SPCR3, spcr);
 	}
 
+	if (xp->speed_hz)
+		spbr = qspi->base_clk / (2 * xp->speed_hz);
+
+	spbr = clamp_val(spbr, bcm_qspi_spbr_min(qspi), QSPI_SPBR_MAX);
+	bcm_qspi_write(qspi, MSPI, MSPI_SPCR0_LSB, spbr);
+
 	qspi->last_parms = *xp;
 }
 
@@ -626,7 +668,7 @@ static int bcm_qspi_setup(struct spi_device *spi)
 {
 	struct bcm_qspi_parms *xp;
 
-	if (spi->bits_per_word > 16)
+	if (spi->bits_per_word > 64)
 		return -EINVAL;
 
 	xp = spi_get_ctldata(spi);
@@ -665,8 +707,12 @@ static int update_qspi_trans_byte_count(struct bcm_qspi *qspi,
 	/* count the last transferred bytes */
 	if (qt->trans->bits_per_word <= 8)
 		qt->byte++;
-	else
+	else if (qt->trans->bits_per_word <= 16)
 		qt->byte += 2;
+	else if (qt->trans->bits_per_word <= 32)
+		qt->byte += 4;
+	else if (qt->trans->bits_per_word <= 64)
+		qt->byte += 8;
 
 	if (qt->byte >= qt->trans->len) {
 		/* we're at the end of the spi_transfer */
@@ -709,6 +755,33 @@ static inline u16 read_rxram_slot_u16(struct bcm_qspi *qspi, int slot)
 		((bcm_qspi_read(qspi, MSPI, msb_offset) & 0xff) << 8);
 }
 
+static inline u32 read_rxram_slot_u32(struct bcm_qspi *qspi, int slot)
+{
+	u32 reg_offset = MSPI_RXRAM;
+	u32 offset = reg_offset + (slot << 3);
+	u32 val;
+
+	val = bcm_qspi_read(qspi, MSPI, offset);
+	val = swap4bytes(val);
+
+	return val;
+}
+
+static inline u64 read_rxram_slot_u64(struct bcm_qspi *qspi, int slot)
+{
+	u32 reg_offset = MSPI_RXRAM;
+	u32 lsb_offset = reg_offset + (slot << 3) + 0x4;
+	u32 msb_offset = reg_offset + (slot << 3);
+	u32 msb, lsb;
+
+	msb = bcm_qspi_read(qspi, MSPI, msb_offset);
+	msb = swap4bytes(msb);
+	lsb = bcm_qspi_read(qspi, MSPI, lsb_offset);
+	lsb = swap4bytes(lsb);
+
+	return ((u64)msb << 32 | lsb);
+}
+
 static void read_from_hw(struct bcm_qspi *qspi, int slots)
 {
 	struct qspi_trans tp;
@@ -732,7 +805,7 @@ static void read_from_hw(struct bcm_qspi *qspi, int slots)
 				buf[tp.byte] = read_rxram_slot_u8(qspi, slot);
 			dev_dbg(&qspi->pdev->dev, "RD %02x\n",
 				buf ? buf[tp.byte] : 0x0);
-		} else {
+		} else if (tp.trans->bits_per_word <= 16) {
 			u16 *buf = tp.trans->rx_buf;
 
 			if (buf)
@@ -740,6 +813,25 @@ static void read_from_hw(struct bcm_qspi *qspi, int slots)
 								      slot);
 			dev_dbg(&qspi->pdev->dev, "RD %04x\n",
 				buf ? buf[tp.byte / 2] : 0x0);
+		} else if (tp.trans->bits_per_word <= 32) {
+			u32 *buf = tp.trans->rx_buf;
+
+			if (buf)
+				buf[tp.byte / 4] = read_rxram_slot_u32(qspi,
+								      slot);
+			dev_dbg(&qspi->pdev->dev, "RD %08x\n",
+				buf ? buf[tp.byte / 4] : 0x0);
+
+		} else if (tp.trans->bits_per_word <= 64) {
+			u64 *buf = tp.trans->rx_buf;
+
+			if (buf)
+				buf[tp.byte / 8] = read_rxram_slot_u64(qspi,
+								      slot);
+			dev_dbg(&qspi->pdev->dev, "RD %llx\n",
+				buf ? buf[tp.byte / 8] : 0x0);
+
+
 		}
 
 		update_qspi_trans_byte_count(qspi, &tp,
@@ -769,6 +861,28 @@ static inline void write_txram_slot_u16(struct bcm_qspi *qspi, int slot,
 	bcm_qspi_write(qspi, MSPI, lsb_offset, (val & 0xff));
 }
 
+static inline void write_txram_slot_u32(struct bcm_qspi *qspi, int slot,
+					u32 val)
+{
+	u32 reg_offset = MSPI_TXRAM;
+	u32 msb_offset = reg_offset + (slot << 3);
+
+	bcm_qspi_write(qspi, MSPI, msb_offset, swap4bytes(val));
+}
+
+static inline void write_txram_slot_u64(struct bcm_qspi *qspi, int slot,
+					u64 val)
+{
+	u32 reg_offset = MSPI_TXRAM;
+	u32 msb_offset = reg_offset + (slot << 3);
+	u32 lsb_offset = reg_offset + (slot << 3) + 0x4;
+	u32 msb = upper_32_bits(val);
+	u32 lsb = lower_32_bits(val);
+
+	bcm_qspi_write(qspi, MSPI, msb_offset, swap4bytes(msb));
+	bcm_qspi_write(qspi, MSPI, lsb_offset, swap4bytes(lsb));
+}
+
 static inline u32 read_cdram_slot(struct bcm_qspi *qspi, int slot)
 {
 	return bcm_qspi_read(qspi, MSPI, MSPI_CDRAM + (slot << 2));
@@ -792,20 +906,39 @@ static int write_to_hw(struct bcm_qspi *qspi, struct spi_device *spi)
 
 	/* Run until end of transfer or reached the max data */
 	while (!tstatus && slot < MSPI_NUM_CDRAM) {
+		mspi_cdram = MSPI_CDRAM_CONT_BIT;
 		if (tp.trans->bits_per_word <= 8) {
 			const u8 *buf = tp.trans->tx_buf;
 			u8 val = buf ? buf[tp.byte] : 0x00;
 
 			write_txram_slot_u8(qspi, slot, val);
 			dev_dbg(&qspi->pdev->dev, "WR %02x\n", val);
-		} else {
+		} else if (tp.trans->bits_per_word <= 16) {
 			const u16 *buf = tp.trans->tx_buf;
 			u16 val = buf ? buf[tp.byte / 2] : 0x0000;
 
 			write_txram_slot_u16(qspi, slot, val);
 			dev_dbg(&qspi->pdev->dev, "WR %04x\n", val);
+		} else if (tp.trans->bits_per_word <= 32) {
+			const u32 *buf = tp.trans->tx_buf;
+			u32 val = buf ? buf[tp.byte/4] : 0x0;
+
+			write_txram_slot_u32(qspi, slot, val);
+			dev_dbg(&qspi->pdev->dev, "WR %08x\n", val);
+		} else if (tp.trans->bits_per_word <= 64) {
+			const u64 *buf = tp.trans->tx_buf;
+			u64 val = (buf ? buf[tp.byte/8] : 0x0);
+
+			/* use the length of delay from SPCR1_LSB */
+			if (bcm_qspi_has_fastbr(qspi))
+				mspi_cdram |= MSPI_CDRAM_DT_BIT;
+
+			write_txram_slot_u64(qspi, slot, val);
+			dev_dbg(&qspi->pdev->dev, "WR %llx\n", val);
 		}
-		mspi_cdram = MSPI_CDRAM_CONT_BIT;
+
+		mspi_cdram |= ((tp.trans->bits_per_word <= 8) ? 0 :
+			       MSPI_CDRAM_BITSE_BIT);
 
 		if (has_bspi(qspi))
 			mspi_cdram &= ~1;
@@ -813,9 +946,6 @@ static int write_to_hw(struct bcm_qspi *qspi, struct spi_device *spi)
 			mspi_cdram |= (~(1 << spi->chip_select) &
 				       MSPI_CDRAM_PCS);
 
-		mspi_cdram |= ((tp.trans->bits_per_word <= 8) ? 0 :
-				MSPI_CDRAM_BITSE_BIT);
-
 		write_cdram_slot(qspi, slot, mspi_cdram);
 
 		tstatus = update_qspi_trans_byte_count(qspi, &tp,
-- 
2.17.1

Re: [PATCH 1/3] spi: bcm-qspi: Add mspi spcr3 32/64-bits xfer mode

[Florian Fainelli]

On 10/8/2021 1:36 PM, Kamal Dasu wrote:
> From: Kamal Dasu <kdasu@broadcom.com>
> 
> Adding 32-bits and 64-bits per transfer modes using the SPCR3
> register settings provided in MSPI controller ver >= 1.5
> 
> Signed-off-by: Kamal Dasu <kdasu@broadcom.com>

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

[PATCH 2/3] spi: bcm-qspi: clear MSPI spifie interrupt during probe

[Kamal Dasu]

From: Kamal Dasu <kdasu@broadcom.com>

Intermittent Kernel crash has been observed on probe in
bcm_qspi_mspi_l2_isr() handler when the MSPI spifie interrupt bit
has not been cleared before registering for interrupts.
Fix the driver to move SoC specific custom interrupt handling code
before we register IRQ in probe. Also clear MSPI interrupt status
resgiter prior to registering IRQ handlers.

Fixes: cc20a38612db ("spi: iproc-qspi: Add Broadcom iProc SoCs support")
Signed-off-by: Kamal Dasu <kdasu@broadcom.com>
---
 drivers/spi/spi-bcm-qspi.c | 77 ++++++++++++++++++++++----------------
 1 file changed, 45 insertions(+), 32 deletions(-)

diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index 9a2d12e7650c..c7c467f15e63 100644
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -1380,10 +1380,14 @@ static void bcm_qspi_hw_init(struct bcm_qspi *qspi)
 
 static void bcm_qspi_hw_uninit(struct bcm_qspi *qspi)
 {
+	u32 status = bcm_qspi_read(qspi, MSPI, MSPI_MSPI_STATUS);
+
 	bcm_qspi_write(qspi, MSPI, MSPI_SPCR2, 0);
 	if (has_bspi(qspi))
 		bcm_qspi_write(qspi, MSPI, MSPI_WRITE_LOCK, 0);
 
+	/* clear interrupt */
+	bcm_qspi_write(qspi, MSPI, MSPI_MSPI_STATUS, status & ~1);
 }
 
 static const struct spi_controller_mem_ops bcm_qspi_mem_ops = {
@@ -1527,6 +1531,47 @@ int bcm_qspi_probe(struct platform_device *pdev,
 	if (!qspi->dev_ids)
 		return -ENOMEM;
 
+	/*
+	 * Some SoCs integrate spi controller (e.g., its interrupt bits)
+	 * in specific ways
+	 */
+	if (soc_intc) {
+		qspi->soc_intc = soc_intc;
+		soc_intc->bcm_qspi_int_set(soc_intc, MSPI_DONE, true);
+	} else {
+		qspi->soc_intc = NULL;
+	}
+
+	if (qspi->clk) {
+		ret = clk_prepare_enable(qspi->clk);
+		if (ret) {
+			dev_err(dev, "failed to prepare clock\n");
+			goto qspi_probe_err;
+		}
+		qspi->base_clk = clk_get_rate(qspi->clk);
+	} else {
+		qspi->base_clk = MSPI_BASE_FREQ;
+	}
+
+	if (data->has_mspi_rev) {
+		rev = bcm_qspi_read(qspi, MSPI, MSPI_REV);
+		/* some older revs do not have a MSPI_REV register */
+		if ((rev & 0xff) == 0xff)
+			rev = 0;
+	}
+
+	qspi->mspi_maj_rev = (rev >> 4) & 0xf;
+	qspi->mspi_min_rev = rev & 0xf;
+	qspi->mspi_spcr3_sysclk = data->has_spcr3_sysclk;
+
+	qspi->max_speed_hz = qspi->base_clk / (bcm_qspi_spbr_min(qspi) * 2);
+
+	/*
+	 * On SW resets it is possible to have the mask still enabled
+	 * Need to disable the mask and clear the status while we init
+	 */
+	bcm_qspi_hw_uninit(qspi);
+
 	for (val = 0; val < num_irqs; val++) {
 		irq = -1;
 		name = qspi_irq_tab[val].irq_name;
@@ -1563,38 +1608,6 @@ int bcm_qspi_probe(struct platform_device *pdev,
 		goto qspi_probe_err;
 	}
 
-	/*
-	 * Some SoCs integrate spi controller (e.g., its interrupt bits)
-	 * in specific ways
-	 */
-	if (soc_intc) {
-		qspi->soc_intc = soc_intc;
-		soc_intc->bcm_qspi_int_set(soc_intc, MSPI_DONE, true);
-	} else {
-		qspi->soc_intc = NULL;
-	}
-
-	ret = clk_prepare_enable(qspi->clk);
-	if (ret) {
-		dev_err(dev, "failed to prepare clock\n");
-		goto qspi_probe_err;
-	}
-
-	qspi->base_clk = clk_get_rate(qspi->clk);
-
-	if (data->has_mspi_rev) {
-		rev = bcm_qspi_read(qspi, MSPI, MSPI_REV);
-		/* some older revs do not have a MSPI_REV register */
-		if ((rev & 0xff) == 0xff)
-			rev = 0;
-	}
-
-	qspi->mspi_maj_rev = (rev >> 4) & 0xf;
-	qspi->mspi_min_rev = rev & 0xf;
-	qspi->mspi_spcr3_sysclk = data->has_spcr3_sysclk;
-
-	qspi->max_speed_hz = qspi->base_clk / (bcm_qspi_spbr_min(qspi) * 2);
-
 	bcm_qspi_hw_init(qspi);
 	init_completion(&qspi->mspi_done);
 	init_completion(&qspi->bspi_done);
-- 
2.17.1

Re: [PATCH 2/3] spi: bcm-qspi: clear MSPI spifie interrupt during probe

[Florian Fainelli]

On 10/8/2021 1:36 PM, Kamal Dasu wrote:
> From: Kamal Dasu <kdasu@broadcom.com>
> 
> Intermittent Kernel crash has been observed on probe in
> bcm_qspi_mspi_l2_isr() handler when the MSPI spifie interrupt bit
> has not been cleared before registering for interrupts.
> Fix the driver to move SoC specific custom interrupt handling code
> before we register IRQ in probe. Also clear MSPI interrupt status
> resgiter prior to registering IRQ handlers.
> 
> Fixes: cc20a38612db ("spi: iproc-qspi: Add Broadcom iProc SoCs support")
> Signed-off-by: Kamal Dasu <kdasu@broadcom.com>

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

Re: [PATCH 2/3] spi: bcm-qspi: clear MSPI spifie interrupt during probe

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 624 bytes --]

On Fri, Oct 08, 2021 at 04:36:02PM -0400, Kamal Dasu wrote:
> From: Kamal Dasu <kdasu@broadcom.com>
> 
> Intermittent Kernel crash has been observed on probe in
> bcm_qspi_mspi_l2_isr() handler when the MSPI spifie interrupt bit
> has not been cleared before registering for interrupts.
> Fix the driver to move SoC specific custom interrupt handling code
> before we register IRQ in probe. Also clear MSPI interrupt status
> resgiter prior to registering IRQ handlers.

Fixes should come at the start of a series before any new code so that
they can be sent as bug fixes without pulling in any of the new work.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

[PATCH 3/3] spi: bcm-qspi: add support for 3-wire mode for half duplex transfer

[Kamal Dasu]

From: Kamal Dasu <kdasu@broadcom.com>

This change configures the MSPI controller to use 3-wire interface when
a slave device devictree nodes indicates this via the optional property.

Signed-off-by: Kamal Dasu <kdasu@broadcom.com>
---
 drivers/spi/spi-bcm-qspi.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index c7c467f15e63..6cb2019cc8fc 100644
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -103,6 +103,7 @@
 #define MSPI_MASTER_BIT			BIT(7)
 
 #define MSPI_NUM_CDRAM				16
+#define MSPI_CDRAM_OUTP				BIT(8)
 #define MSPI_CDRAM_CONT_BIT			BIT(7)
 #define MSPI_CDRAM_BITSE_BIT			BIT(6)
 #define MSPI_CDRAM_DT_BIT			BIT(5)
@@ -122,6 +123,8 @@
 #define MSPI_SPCR3_DAM_8BYTE			0
 #define MSPI_SPCR3_DAM_16BYTE			(BIT(2) | BIT(4))
 #define MSPI_SPCR3_DAM_32BYTE			(BIT(3) | BIT(5))
+#define MSPI_SPCR3_HALFDUPLEX			BIT(6)
+#define MSPI_SPCR3_HDOUTTYPE			BIT(7)
 #define MSPI_SPCR3_DATA_REG_SZ			BIT(8)
 #define MSPI_SPCR3_CPHARX			BIT(9)
 
@@ -613,6 +616,9 @@ static void bcm_qspi_hw_set_parms(struct bcm_qspi *qspi,
 		/* enable fastbr */
 		spcr |=	MSPI_SPCR3_FASTBR;
 
+		if (xp->mode & SPI_3WIRE)
+			spcr |= MSPI_SPCR3_HALFDUPLEX |  MSPI_SPCR3_HDOUTTYPE;
+
 		if (bcm_qspi_has_sysclk_108(qspi)) {
 			/* SYSCLK_108 */
 			spcr |= MSPI_SPCR3_SYSCLKSEL_108;
@@ -940,6 +946,10 @@ static int write_to_hw(struct bcm_qspi *qspi, struct spi_device *spi)
 		mspi_cdram |= ((tp.trans->bits_per_word <= 8) ? 0 :
 			       MSPI_CDRAM_BITSE_BIT);
 
+		/* set 3wrire halfduplex mode data from master to slave */
+		if ((spi->mode & SPI_3WIRE) && tp.trans->tx_buf)
+			mspi_cdram |= MSPI_CDRAM_OUTP;
+
 		if (has_bspi(qspi))
 			mspi_cdram &= ~1;
 		else
@@ -1480,7 +1490,8 @@ int bcm_qspi_probe(struct platform_device *pdev,
 	qspi->master = master;
 
 	master->bus_num = -1;
-	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_RX_DUAL | SPI_RX_QUAD;
+	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_RX_DUAL | SPI_RX_QUAD |
+				SPI_3WIRE;
 	master->setup = bcm_qspi_setup;
 	master->transfer_one = bcm_qspi_transfer_one;
 	master->mem_ops = &bcm_qspi_mem_ops;
-- 
2.17.1

Re: [PATCH 3/3] spi: bcm-qspi: add support for 3-wire mode for half duplex transfer

[Florian Fainelli]

On 10/8/2021 1:36 PM, Kamal Dasu wrote:
> From: Kamal Dasu <kdasu@broadcom.com>
> 
> This change configures the MSPI controller to use 3-wire interface when
> a slave device devictree nodes indicates this via the optional property.
> 
> Signed-off-by: Kamal Dasu <kdasu@broadcom.com>

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

Re: [PATCH 0/3] spi-bcm-qspi spcr3 enahancements

[Mark Brown]

On Fri, 8 Oct 2021 16:36:00 -0400, Kamal Dasu wrote:
> This change set feature enahancements for spcr3 transfer modes as well as
> adds support for half-duplex 3-wire mode transfer.
> 
> Kamal Dasu (3):
>   spi: bcm-qspi: Add mspi spcr3 32/64-bits xfer mode
>   spi: bcm-qspi: clear MSPI spifie interrupt during probe
>   spi: bcm-qspi: add support for 3-wire mode for half duplex transfer
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/3] spi: bcm-qspi: Add mspi spcr3 32/64-bits xfer mode
      commit: ee4d62c47326c69e57180da53c057e55f0e73e35
[2/3] spi: bcm-qspi: clear MSPI spifie interrupt during probe
      commit: 75b3cb97eb1f05042745c0655a7145b0262d4c5c
[3/3] spi: bcm-qspi: add support for 3-wire mode for half duplex transfer
      commit: e81cd07dcf50ef4811f6667dba89c5614278cbdd

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark