[PATCH v2 00/10] spi: spi-sun6i: One fix and some improvements

[PATCH v2 00/10] spi: spi-sun6i: One fix and some improvements

[Marc Kleine-Budde]

Hello,

this series first fixes the calculation of the clock rate. The driver will
round up to the nearest clock rate instead of rounding down. Resulting in SPI
devices accessed with a too high SPI clock.

The remaining patches improve the performance of the driver. The changes range
from micro-optimizations like reducing MMIO writes to the controller to
reducing the number of needed interrupts in some use cases.

regards,
Marc

changes since v1:
- added Maxime Ripard's to the existing patches
- 06/10: (was 05/10 in v1)
  "spi: spi-sun6i: sun6i_spi_drain_fifo(): introduce sun6i_spi_get_rx_fifo_count() and make use of it"
  use FIELD_GET instead of open coding it
  (tnx: Maxime Ripard)
- 05/10: "spi: spi-sun6i: sun6i_spi_get_tx_fifo_count: Convert manual shift+mask to FIELD_GET()"
  new patch




_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 01/10] spi: spi-sun6i: sun6i_spi_transfer_one(): fix setting of clock rate

[Marc Kleine-Budde]

A SPI transfer defines the _maximum_ speed of the SPI transfer. However the
driver doesn't take into account that the clock divider is always rounded down
(due to integer arithmetics). This results in a too high clock rate for the SPI
transfer.

E.g.: with a mclk_rate of 24 MHz and a SPI transfer speed of 10 MHz, the
original code calculates a reg of "0", which results in a effective divider of
"2" and a 12 MHz clock for the SPI transfer.

This patch fixes the issue by using DIV_ROUND_UP() instead of a plain
integer division.

While there simplify the divider calculation for the CDR1 case, use
order_base_2() instead of two ilog2() calculations.

Fixes: 3558fe900e8a ("spi: sunxi: Add Allwinner A31 SPI controller driver")
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/spi/spi-sun6i.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index ecea15534c42..fa11cc0e809b 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -198,7 +198,7 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 				  struct spi_transfer *tfr)
 {
 	struct sun6i_spi *sspi = spi_master_get_devdata(master);
-	unsigned int mclk_rate, div, timeout;
+	unsigned int mclk_rate, div, div_cdr1, div_cdr2, timeout;
 	unsigned int start, end, tx_time;
 	unsigned int trig_level;
 	unsigned int tx_len = 0;
@@ -287,14 +287,12 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 	 * First try CDR2, and if we can't reach the expected
 	 * frequency, fall back to CDR1.
 	 */
-	div = mclk_rate / (2 * tfr->speed_hz);
-	if (div <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) {
-		if (div > 0)
-			div--;
-
-		reg = SUN6I_CLK_CTL_CDR2(div) | SUN6I_CLK_CTL_DRS;
+	div_cdr1 = DIV_ROUND_UP(mclk_rate, tfr->speed_hz);
+	div_cdr2 = DIV_ROUND_UP(div_cdr1, 2);
+	if (div_cdr2 <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) {
+		reg = SUN6I_CLK_CTL_CDR2(div_cdr2 - 1) | SUN6I_CLK_CTL_DRS;
 	} else {
-		div = ilog2(mclk_rate) - ilog2(tfr->speed_hz);
+		div = min(SUN6I_CLK_CTL_CDR1_MASK, order_base_2(div_cdr1));
 		reg = SUN6I_CLK_CTL_CDR1(div);
 	}
 
-- 
2.27.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 02/10] spi: spi-sun6i: sun6i_spi_transfer_one(): report effectivly used speed_hz of transfer

[Marc Kleine-Budde]

This patch implementes the reporting of the effectivly used speed_hz for the
transfer by setting tfr->effective_speed_hz.

See the following patch, which adds this feature to the SPI core for more
information:

    5d7e2b5ed585 spi: core: allow reporting the effectivly used speed_hz for a transfer

Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/spi/spi-sun6i.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index fa11cc0e809b..64b4d8077010 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -291,9 +291,11 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 	div_cdr2 = DIV_ROUND_UP(div_cdr1, 2);
 	if (div_cdr2 <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) {
 		reg = SUN6I_CLK_CTL_CDR2(div_cdr2 - 1) | SUN6I_CLK_CTL_DRS;
+		tfr->effective_speed_hz = mclk_rate / (2 * div_cdr2);
 	} else {
 		div = min(SUN6I_CLK_CTL_CDR1_MASK, order_base_2(div_cdr1));
 		reg = SUN6I_CLK_CTL_CDR1(div);
+		tfr->effective_speed_hz = mclk_rate / (1 << div);
 	}
 
 	sun6i_spi_write(sspi, SUN6I_CLK_CTL_REG, reg);
-- 
2.27.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 03/10] spi: spi-sun6i: sun6i_spi_transfer_one(): remove useless goto

[Marc Kleine-Budde]

This patch removes an useless goto at the end of
sun6i_spi_transfer_one().

Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/spi/spi-sun6i.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 64b4d8077010..955be8921c45 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -335,10 +335,8 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 			 dev_name(&spi->dev), tfr->len, tfr->speed_hz,
 			 jiffies_to_msecs(end - start), tx_time);
 		ret = -ETIMEDOUT;
-		goto out;
 	}
 
-out:
 	sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0);
 
 	return ret;
-- 
2.27.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 04/10] spi: spi-sun6i: sun6i_spi_transfer_one(): remove not needed masking of transfer length

[Marc Kleine-Budde]

In sun6i_spi_transfer_one() the driver ensures that the length of the transfer
is smaller or equal to SUN6I_MAX_XFER_SIZE. This means the masking of the
length to SUN6I_MAX_XFER_SIZE can be skipped when writing the transfer length
into the registers.

This patch removes the useless masking of the transfer length to
SUN6I_MAX_XFER_SIZE.

Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/spi/spi-sun6i.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 955be8921c45..882492774986 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -73,13 +73,10 @@
 #define SUN6I_MAX_XFER_SIZE		0xffffff
 
 #define SUN6I_BURST_CNT_REG		0x30
-#define SUN6I_BURST_CNT(cnt)			((cnt) & SUN6I_MAX_XFER_SIZE)
 
 #define SUN6I_XMIT_CNT_REG		0x34
-#define SUN6I_XMIT_CNT(cnt)			((cnt) & SUN6I_MAX_XFER_SIZE)
 
 #define SUN6I_BURST_CTL_CNT_REG		0x38
-#define SUN6I_BURST_CTL_CNT_STC(cnt)		((cnt) & SUN6I_MAX_XFER_SIZE)
 
 #define SUN6I_TXDATA_REG		0x200
 #define SUN6I_RXDATA_REG		0x300
@@ -305,10 +302,9 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 		tx_len = tfr->len;
 
 	/* Setup the counters */
-	sun6i_spi_write(sspi, SUN6I_BURST_CNT_REG, SUN6I_BURST_CNT(tfr->len));
-	sun6i_spi_write(sspi, SUN6I_XMIT_CNT_REG, SUN6I_XMIT_CNT(tx_len));
-	sun6i_spi_write(sspi, SUN6I_BURST_CTL_CNT_REG,
-			SUN6I_BURST_CTL_CNT_STC(tx_len));
+	sun6i_spi_write(sspi, SUN6I_BURST_CNT_REG, tfr->len);
+	sun6i_spi_write(sspi, SUN6I_XMIT_CNT_REG, tx_len);
+	sun6i_spi_write(sspi, SUN6I_BURST_CTL_CNT_REG, tx_len);
 
 	/* Fill the TX FIFO */
 	sun6i_spi_fill_fifo(sspi, sspi->fifo_depth);
-- 
2.27.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 05/10] spi: spi-sun6i: sun6i_spi_get_tx_fifo_count: Convert manual shift+mask to FIELD_GET()

[Marc Kleine-Budde]

This patch converts the manual shift+mask in sun6i_spi_get_tx_fifo_count() to
make use of FIELD_GET()

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/spi/spi-sun6i.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 882492774986..40365761f25d 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -7,6 +7,7 @@
  * Maxime Ripard <maxime.ripard@free-electrons.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/device.h>
@@ -60,8 +61,7 @@
 #define SUN6I_FIFO_STA_REG		0x1c
 #define SUN6I_FIFO_STA_RF_CNT_MASK		0x7f
 #define SUN6I_FIFO_STA_RF_CNT_BITS		0
-#define SUN6I_FIFO_STA_TF_CNT_MASK		0x7f
-#define SUN6I_FIFO_STA_TF_CNT_BITS		16
+#define SUN6I_FIFO_STA_TF_CNT_MASK		GENMASK(23, 16)
 
 #define SUN6I_CLK_CTL_REG		0x24
 #define SUN6I_CLK_CTL_CDR2_MASK			0xff
@@ -110,9 +110,7 @@ static inline u32 sun6i_spi_get_tx_fifo_count(struct sun6i_spi *sspi)
 {
 	u32 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
 
-	reg >>= SUN6I_FIFO_STA_TF_CNT_BITS;
-
-	return reg & SUN6I_FIFO_STA_TF_CNT_MASK;
+	return FIELD_GET(SUN6I_FIFO_STA_TF_CNT_MASK, reg);
 }
 
 static inline void sun6i_spi_enable_interrupt(struct sun6i_spi *sspi, u32 mask)
-- 
2.27.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 06/10] spi: spi-sun6i: sun6i_spi_drain_fifo(): introduce sun6i_spi_get_rx_fifo_count() and make use of it

[Marc Kleine-Budde]

This patch introduces the function sun6i_spi_get_rx_fifo_count(), similar to
the existing sun6i_spi_get_tx_fifo_count(), to make the sun6i_spi_drain_fifo()
function a bit easier to read.

Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/spi/spi-sun6i.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 40365761f25d..44cd07331627 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -59,8 +59,7 @@
 #define SUN6I_FIFO_CTL_TF_RST			BIT(31)
 
 #define SUN6I_FIFO_STA_REG		0x1c
-#define SUN6I_FIFO_STA_RF_CNT_MASK		0x7f
-#define SUN6I_FIFO_STA_RF_CNT_BITS		0
+#define SUN6I_FIFO_STA_RF_CNT_MASK		GENMASK(7, 0)
 #define SUN6I_FIFO_STA_TF_CNT_MASK		GENMASK(23, 16)
 
 #define SUN6I_CLK_CTL_REG		0x24
@@ -106,6 +105,13 @@ static inline void sun6i_spi_write(struct sun6i_spi *sspi, u32 reg, u32 value)
 	writel(value, sspi->base_addr + reg);
 }
 
+static inline u32 sun6i_spi_get_rx_fifo_count(struct sun6i_spi *sspi)
+{
+	u32 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
+
+	return FIELD_GET(SUN6I_FIFO_STA_RF_CNT_MASK, reg);
+}
+
 static inline u32 sun6i_spi_get_tx_fifo_count(struct sun6i_spi *sspi)
 {
 	u32 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
@@ -131,13 +137,11 @@ static inline void sun6i_spi_disable_interrupt(struct sun6i_spi *sspi, u32 mask)
 
 static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi, int len)
 {
-	u32 reg, cnt;
+	u32 cnt;
 	u8 byte;
 
 	/* See how much data is available */
-	reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
-	reg &= SUN6I_FIFO_STA_RF_CNT_MASK;
-	cnt = reg >> SUN6I_FIFO_STA_RF_CNT_BITS;
+	cnt = sun6i_spi_get_rx_fifo_count(sspi);
 
 	if (len > cnt)
 		len = cnt;
-- 
2.27.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 07/10] spi: spi-sun6i: sun6i_spi_drain_fifo(): remove not needed length argument

[Marc Kleine-Budde]

The function sun6i_spi_drain_fifo() is called with a length argument of
"sspi->fifo_depth" and "SUN6I_FIFO_DEPTH".

The driver reads the number of available bytes to read from the FIFO from the
hardware and uses the length argument to limit this value. This is not needed
as the FIFO can contain only the fifo depth number of bytes.

This patch removes the length argument and check.

Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/spi/spi-sun6i.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 44cd07331627..5849b65c3b1c 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -135,16 +135,13 @@ static inline void sun6i_spi_disable_interrupt(struct sun6i_spi *sspi, u32 mask)
 	sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
 }
 
-static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi, int len)
+static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi)
 {
-	u32 cnt;
+	u32 len;
 	u8 byte;
 
 	/* See how much data is available */
-	cnt = sun6i_spi_get_rx_fifo_count(sspi);
-
-	if (len > cnt)
-		len = cnt;
+	len = sun6i_spi_get_rx_fifo_count(sspi);
 
 	while (len--) {
 		byte = readb(sspi->base_addr + SUN6I_RXDATA_REG);
@@ -348,14 +345,14 @@ static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
 	/* Transfer complete */
 	if (status & SUN6I_INT_CTL_TC) {
 		sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TC);
-		sun6i_spi_drain_fifo(sspi, sspi->fifo_depth);
+		sun6i_spi_drain_fifo(sspi);
 		complete(&sspi->done);
 		return IRQ_HANDLED;
 	}
 
 	/* Receive FIFO 3/4 full */
 	if (status & SUN6I_INT_CTL_RF_RDY) {
-		sun6i_spi_drain_fifo(sspi, SUN6I_FIFO_DEPTH);
+		sun6i_spi_drain_fifo(sspi);
 		/* Only clear the interrupt _after_ draining the FIFO */
 		sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_RF_RDY);
 		return IRQ_HANDLED;
-- 
2.27.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 08/10] spi: spi-sun6i: sun6i_spi_fill_fifo(): remove not needed length argument

[Marc Kleine-Budde]

The function sun6i_spi_fill_fifo() is called with a length argument of
"sspi->fifo_depth" and "SUN6I_FIFO_DEPTH".

The driver reads the number of free bytes in the FIFO from the hardware and
uses the length argument to limit this value. This is not needed as the number
of free bytes in the FIFO is always less or equal the depth of the FIFO.

This patch removes the length argument and check.

Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/spi/spi-sun6i.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 5849b65c3b1c..2442006c4229 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -150,15 +150,16 @@ static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi)
 	}
 }
 
-static inline void sun6i_spi_fill_fifo(struct sun6i_spi *sspi, int len)
+static inline void sun6i_spi_fill_fifo(struct sun6i_spi *sspi)
 {
 	u32 cnt;
+	int len;
 	u8 byte;
 
 	/* See how much data we can fit */
 	cnt = sspi->fifo_depth - sun6i_spi_get_tx_fifo_count(sspi);
 
-	len = min3(len, (int)cnt, sspi->len);
+	len = min((int)cnt, sspi->len);
 
 	while (len--) {
 		byte = sspi->tx_buf ? *sspi->tx_buf++ : 0;
@@ -306,7 +307,7 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 	sun6i_spi_write(sspi, SUN6I_BURST_CTL_CNT_REG, tx_len);
 
 	/* Fill the TX FIFO */
-	sun6i_spi_fill_fifo(sspi, sspi->fifo_depth);
+	sun6i_spi_fill_fifo(sspi);
 
 	/* Enable the interrupts */
 	sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, SUN6I_INT_CTL_TC);
@@ -360,7 +361,7 @@ static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
 
 	/* Transmit FIFO 3/4 empty */
 	if (status & SUN6I_INT_CTL_TF_ERQ) {
-		sun6i_spi_fill_fifo(sspi, SUN6I_FIFO_DEPTH);
+		sun6i_spi_fill_fifo(sspi);
 
 		if (!sspi->len)
 			/* nothing left to transmit */
-- 
2.27.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 09/10] spi: spi-sun6i: sun6i_spi_transfer_one(): collate write to Interrupt Control Register

[Marc Kleine-Budde]

In sun6i_spi_transfer_one() the Interrupt Control Register is written three
times. This patch collates the three writes into one.

Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/spi/spi-sun6i.c | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 2442006c4229..bba9843c40c5 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -119,14 +119,6 @@ static inline u32 sun6i_spi_get_tx_fifo_count(struct sun6i_spi *sspi)
 	return FIELD_GET(SUN6I_FIFO_STA_TF_CNT_MASK, reg);
 }
 
-static inline void sun6i_spi_enable_interrupt(struct sun6i_spi *sspi, u32 mask)
-{
-	u32 reg = sun6i_spi_read(sspi, SUN6I_INT_CTL_REG);
-
-	reg |= mask;
-	sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
-}
-
 static inline void sun6i_spi_disable_interrupt(struct sun6i_spi *sspi, u32 mask)
 {
 	u32 reg = sun6i_spi_read(sspi, SUN6I_INT_CTL_REG);
@@ -310,11 +302,12 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 	sun6i_spi_fill_fifo(sspi);
 
 	/* Enable the interrupts */
-	sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, SUN6I_INT_CTL_TC);
-	sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TC |
-					 SUN6I_INT_CTL_RF_RDY);
+	reg = SUN6I_INT_CTL_TC | SUN6I_INT_CTL_RF_RDY;
+
 	if (tx_len > sspi->fifo_depth)
-		sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ);
+		reg |= SUN6I_INT_CTL_TF_ERQ;
+
+	sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
 
 	/* Start the transfer */
 	reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
-- 
2.27.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v2 10/10] spi: spi-sun6i: sun6i_spi_transfer_one(): enable RF_RDY interrupt only if needed

[Marc Kleine-Budde]

In sun6i_spi_transfer_one() the RX FIFO Ready (SUN6I_INT_CTL_RF_RDY) is
unconditionally enabled.

A RX interrupt is only needed, if more data than fits into the FIFO is going to
be received during this transfer. As the RX-FIFO is drained during transfer
complete interrupt, enable the RX FIFO Ready interrupt only if the data doesn't
fit into the FIFO.

Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/spi/spi-sun6i.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index bba9843c40c5..19238e1b76b4 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -190,7 +190,7 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 	unsigned int mclk_rate, div, div_cdr1, div_cdr2, timeout;
 	unsigned int start, end, tx_time;
 	unsigned int trig_level;
-	unsigned int tx_len = 0;
+	unsigned int tx_len = 0, rx_len = 0;
 	int ret = 0;
 	u32 reg;
 
@@ -245,10 +245,12 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 	 * If it's a TX only transfer, we don't want to fill the RX
 	 * FIFO with bogus data
 	 */
-	if (sspi->rx_buf)
+	if (sspi->rx_buf) {
 		reg &= ~SUN6I_TFR_CTL_DHB;
-	else
+		rx_len = tfr->len;
+	} else {
 		reg |= SUN6I_TFR_CTL_DHB;
+	}
 
 	/* We want to control the chip select manually */
 	reg |= SUN6I_TFR_CTL_CS_MANUAL;
@@ -302,8 +304,10 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 	sun6i_spi_fill_fifo(sspi);
 
 	/* Enable the interrupts */
-	reg = SUN6I_INT_CTL_TC | SUN6I_INT_CTL_RF_RDY;
+	reg = SUN6I_INT_CTL_TC;
 
+	if (rx_len > sspi->fifo_depth)
+		reg |= SUN6I_INT_CTL_RF_RDY;
 	if (tx_len > sspi->fifo_depth)
 		reg |= SUN6I_INT_CTL_TF_ERQ;
 
-- 
2.27.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v2 00/10] spi: spi-sun6i: One fix and some improvements

[Mark Brown]

On Mon, 6 Jul 2020 16:34:33 +0200, Marc Kleine-Budde wrote:
> this series first fixes the calculation of the clock rate. The driver will
> round up to the nearest clock rate instead of rounding down. Resulting in SPI
> devices accessed with a too high SPI clock.
> 
> The remaining patches improve the performance of the driver. The changes range
> from micro-optimizations like reducing MMIO writes to the controller to
> reducing the number of needed interrupts in some use cases.
> 
> [...]

Applied to

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

Thanks!

[1/1] spi: spi-sun6i: sun6i_spi_transfer_one(): fix setting of clock rate
      commit: ed7815db70d17b1741883f2da8e1d80bc2efe517

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

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v2 00/10] spi: spi-sun6i: One fix and some improvements

[Mark Brown]

On Mon, 6 Jul 2020 16:34:33 +0200, Marc Kleine-Budde wrote:
> this series first fixes the calculation of the clock rate. The driver will
> round up to the nearest clock rate instead of rounding down. Resulting in SPI
> devices accessed with a too high SPI clock.
> 
> The remaining patches improve the performance of the driver. The changes range
> from micro-optimizations like reducing MMIO writes to the controller to
> reducing the number of needed interrupts in some use cases.
> 
> [...]

Applied to

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

Thanks!

[01/10] spi: spi-sun6i: sun6i_spi_transfer_one(): fix setting of clock rate
        commit: ed7815db70d17b1741883f2da8e1d80bc2efe517
[02/10] spi: spi-sun6i: sun6i_spi_transfer_one(): report effectivly used speed_hz of transfer
        (no commit info)
[03/10] spi: spi-sun6i: sun6i_spi_transfer_one(): remove useless goto
        (no commit info)
[04/10] spi: spi-sun6i: sun6i_spi_transfer_one(): remove not needed masking of transfer length
        (no commit info)
[05/10] spi: spi-sun6i: sun6i_spi_get_tx_fifo_count: Convert manual shift+mask to FIELD_GET()
        (no commit info)
[06/10] spi: spi-sun6i: sun6i_spi_drain_fifo(): introduce sun6i_spi_get_rx_fifo_count() and make use of it
        (no commit info)
[07/10] spi: spi-sun6i: sun6i_spi_drain_fifo(): remove not needed length argument
        (no commit info)
[08/10] spi: spi-sun6i: sun6i_spi_fill_fifo(): remove not needed length argument
        (no commit info)
[09/10] spi: spi-sun6i: sun6i_spi_transfer_one(): collate write to Interrupt Control Register
        (no commit info)
[10/10] spi: spi-sun6i: sun6i_spi_transfer_one(): enable RF_RDY interrupt only if needed
        (no commit info)

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

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v2 00/10] spi: spi-sun6i: One fix and some improvements

[Mark Brown]

On Mon, 6 Jul 2020 16:34:33 +0200, Marc Kleine-Budde wrote:
> this series first fixes the calculation of the clock rate. The driver will
> round up to the nearest clock rate instead of rounding down. Resulting in SPI
> devices accessed with a too high SPI clock.
> 
> The remaining patches improve the performance of the driver. The changes range
> from micro-optimizations like reducing MMIO writes to the controller to
> reducing the number of needed interrupts in some use cases.
> 
> [...]

Applied to

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

Thanks!

[01/10] spi: spi-sun6i: sun6i_spi_transfer_one(): fix setting of clock rate
        commit: ed7815db70d17b1741883f2da8e1d80bc2efe517
[02/10] spi: spi-sun6i: sun6i_spi_transfer_one(): report effectivly used speed_hz of transfer
        commit: 09a7139e9e172e70cd980c45e01a49e3c2630864
[03/10] spi: spi-sun6i: sun6i_spi_transfer_one(): remove useless goto
        commit: 642d75131c8cab1f355f513bd19e90960720b839
[04/10] spi: spi-sun6i: sun6i_spi_transfer_one(): remove not needed masking of transfer length
        commit: 05bf34283c8e1c44bcae9bdb9c07df6769cdc995
[05/10] spi: spi-sun6i: sun6i_spi_get_tx_fifo_count: Convert manual shift+mask to FIELD_GET()
        commit: e0430d9040983ab05f59136f4291ae04e01e1e30
[06/10] spi: spi-sun6i: sun6i_spi_drain_fifo(): introduce sun6i_spi_get_rx_fifo_count() and make use of it
        commit: 9bfc242a93792b298b95003c691f46b838de0482
[07/10] spi: spi-sun6i: sun6i_spi_drain_fifo(): remove not needed length argument
        commit: 60b1f09675f2330c84055cb11389c6212fe53cec
[08/10] spi: spi-sun6i: sun6i_spi_fill_fifo(): remove not needed length argument
        commit: 15254b028dd6cf67e06dbc963fbd0c1cae33e35a
[09/10] spi: spi-sun6i: sun6i_spi_transfer_one(): collate write to Interrupt Control Register
        commit: 1e9ca016b623a3560831df811bc1eaa29b30359c
[10/10] spi: spi-sun6i: sun6i_spi_transfer_one(): enable RF_RDY interrupt only if needed
        commit: 878d4d57a6e5d3feae1f8a247ca04d3bfbc553cc

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

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v2 00/10] spi: spi-sun6i: One fix and some improvements

[Mark Brown]

On Mon, 6 Jul 2020 16:34:33 +0200, Marc Kleine-Budde wrote:
> this series first fixes the calculation of the clock rate. The driver will
> round up to the nearest clock rate instead of rounding down. Resulting in SPI
> devices accessed with a too high SPI clock.
> 
> The remaining patches improve the performance of the driver. The changes range
> from micro-optimizations like reducing MMIO writes to the controller to
> reducing the number of needed interrupts in some use cases.
> 
> [...]

Applied to

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

Thanks!

[01/10] spi: spi-sun6i: sun6i_spi_transfer_one(): fix setting of clock rate
        commit: ed7815db70d17b1741883f2da8e1d80bc2efe517
[02/10] spi: spi-sun6i: sun6i_spi_transfer_one(): report effectivly used speed_hz of transfer
        commit: 09a7139e9e172e70cd980c45e01a49e3c2630864
[03/10] spi: spi-sun6i: sun6i_spi_transfer_one(): remove useless goto
        commit: 642d75131c8cab1f355f513bd19e90960720b839
[04/10] spi: spi-sun6i: sun6i_spi_transfer_one(): remove not needed masking of transfer length
        commit: 05bf34283c8e1c44bcae9bdb9c07df6769cdc995
[05/10] spi: spi-sun6i: sun6i_spi_get_tx_fifo_count: Convert manual shift+mask to FIELD_GET()
        commit: e0430d9040983ab05f59136f4291ae04e01e1e30
[06/10] spi: spi-sun6i: sun6i_spi_drain_fifo(): introduce sun6i_spi_get_rx_fifo_count() and make use of it
        commit: 9bfc242a93792b298b95003c691f46b838de0482
[07/10] spi: spi-sun6i: sun6i_spi_drain_fifo(): remove not needed length argument
        commit: 60b1f09675f2330c84055cb11389c6212fe53cec
[08/10] spi: spi-sun6i: sun6i_spi_fill_fifo(): remove not needed length argument
        commit: 15254b028dd6cf67e06dbc963fbd0c1cae33e35a
[09/10] spi: spi-sun6i: sun6i_spi_transfer_one(): collate write to Interrupt Control Register
        commit: 1e9ca016b623a3560831df811bc1eaa29b30359c
[10/10] spi: spi-sun6i: sun6i_spi_transfer_one(): enable RF_RDY interrupt only if needed
        commit: 878d4d57a6e5d3feae1f8a247ca04d3bfbc553cc

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

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel