[PATCH 4.9 061/128] spi: dw: Enable interrupts in accordance with DMA xfer mode

[PATCH 4.9 061/128] spi: dw: Enable interrupts in accordance with DMA xfer mode

[Greg Kroah-Hartman]

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

[ Upstream commit 43dba9f3f98c2b184a19f856f06fe22817bfd9e0 ]

It's pointless to track the Tx overrun interrupts if Rx-only SPI
transfer is issued. Similarly there is no need in handling the Rx
overrun/underrun interrupts if Tx-only SPI transfer is executed.
So lets unmask the interrupts only if corresponding SPI
transactions are implied.

Co-developed-by: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Signed-off-by: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Link: https://lore.kernel.org/r/20200522000806.7381-3-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spi-dw-mid.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index f77d03b658ab..fe0ca3848d35 100644
--- a/drivers/spi/spi-dw-mid.c
+++ b/drivers/spi/spi-dw-mid.c
@@ -228,19 +228,23 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws,
 
 static int mid_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer)
 {
-	u16 dma_ctrl = 0;
+	u16 imr = 0, dma_ctrl = 0;
 
 	dw_writel(dws, DW_SPI_DMARDLR, 0xf);
 	dw_writel(dws, DW_SPI_DMATDLR, 0x10);
 
-	if (xfer->tx_buf)
+	if (xfer->tx_buf) {
 		dma_ctrl |= SPI_DMA_TDMAE;
-	if (xfer->rx_buf)
+		imr |= SPI_INT_TXOI;
+	}
+	if (xfer->rx_buf) {
 		dma_ctrl |= SPI_DMA_RDMAE;
+		imr |= SPI_INT_RXUI | SPI_INT_RXOI;
+	}
 	dw_writel(dws, DW_SPI_DMACR, dma_ctrl);
 
 	/* Set the interrupt mask */
-	spi_umask_intr(dws, SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI);
+	spi_umask_intr(dws, imr);
 
 	dws->transfer_handler = dma_transfer;
 
-- 
2.25.1

[PATCH 4.9 062/128] clocksource: dw_apb_timer_of: Fix missing clockevent timers

[Greg Kroah-Hartman]

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

[ Upstream commit 6d2e16a3181bafb77b535095c39ad1c8b9558c8c ]

Commit 100214889973 ("clocksource: dw_apb_timer_of: use
clocksource_of_init") replaced a publicly available driver
initialization method with one called by the timer_probe() method
available after CLKSRC_OF. In current implementation it traverses
all the timers available in the system and calls their initialization
methods if corresponding devices were either in dtb or in acpi. But
if before the commit any number of available timers would be installed
as clockevent and clocksource devices, after that there would be at most
two. The rest are just ignored since default case branch doesn't do
anything. I don't see a reason of such behaviour, neither the commit
message explains it. Moreover this might be wrong if on some platforms
these timers might be used for different purpose, as virtually CPU-local
clockevent timers and as an independent broadcast timer. So in order
to keep the compatibility with the platforms where the order of the
timers detection has some meaning, lets add the secondly discovered
timer to be of clocksource/sched_clock type, while the very first and
the others would provide the clockevents service.

Fixes: 100214889973 ("clocksource: dw_apb_timer_of: use clocksource_of_init")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-rtc@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200521204818.25436-7-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/clocksource/dw_apb_timer_of.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
index aee6c0d39a7c..024e6cc5025b 100644
--- a/drivers/clocksource/dw_apb_timer_of.c
+++ b/drivers/clocksource/dw_apb_timer_of.c
@@ -146,10 +146,6 @@ static int num_called;
 static int __init dw_apb_timer_init(struct device_node *timer)
 {
 	switch (num_called) {
-	case 0:
-		pr_debug("%s: found clockevent timer\n", __func__);
-		add_clockevent(timer);
-		break;
 	case 1:
 		pr_debug("%s: found clocksource timer\n", __func__);
 		add_clocksource(timer);
@@ -160,6 +156,8 @@ static int __init dw_apb_timer_init(struct device_node *timer)
 #endif
 		break;
 	default:
+		pr_debug("%s: found clockevent timer\n", __func__);
+		add_clockevent(timer);
 		break;
 	}
 
-- 
2.25.1

[PATCH 4.9 095/128] spi: dw: Return any value retrieved from the dma_transfer callback

[Greg Kroah-Hartman]

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

[ Upstream commit f0410bbf7d0fb80149e3b17d11d31f5b5197873e ]

DW APB SSI DMA-part of the driver may need to perform the requested
SPI-transfer synchronously. In that case the dma_transfer() callback
will return 0 as a marker of the SPI transfer being finished so the
SPI core doesn't need to wait and may proceed with the SPI message
trasnfers pumping procedure. This will be needed to fix the problem
when DMA transactions are finished, but there is still data left in
the SPI Tx/Rx FIFOs being sent/received. But for now make dma_transfer
to return 1 as the normal dw_spi_transfer_one() method.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Link: https://lore.kernel.org/r/20200529131205.31838-3-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spi-dw-mid.c | 2 +-
 drivers/spi/spi-dw.c     | 7 ++-----
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index fe0ca3848d35..c079ab36275f 100644
--- a/drivers/spi/spi-dw-mid.c
+++ b/drivers/spi/spi-dw-mid.c
@@ -274,7 +274,7 @@ static int mid_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer)
 		dma_async_issue_pending(dws->txchan);
 	}
 
-	return 0;
+	return 1;
 }
 
 static void mid_spi_dma_stop(struct dw_spi *dws)
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index c5a2f369941c..91f44e3e1930 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -384,11 +384,8 @@ static int dw_spi_transfer_one(struct spi_master *master,
 
 	spi_enable_chip(dws, 1);
 
-	if (dws->dma_mapped) {
-		ret = dws->dma_ops->dma_transfer(dws, transfer);
-		if (ret < 0)
-			return ret;
-	}
+	if (dws->dma_mapped)
+		return dws->dma_ops->dma_transfer(dws, transfer);
 
 	if (chip->poll_mode)
 		return poll_transfer(dws);
-- 
2.25.1