[PATCH 0/6] spi: rspi: Add support for multiple native and GPIO chip selects

[PATCH 0/6] spi: rspi: Add support for multiple native and GPIO chip selects

[Geert Uytterhoeven]

	Hi all,

Currently the Renesas SPI (RSPI/QSPI) driver supports a single native
chip select only.  This patch series adds support for multiple native
and GPIO chip selects.

As the RSPI controller always drives a native chip select when
performing a transfer, at least one native chip select must be left
unused, just like on MSIOF.  To avoid code duplication, the first two
patches add generic handling of unused native chip selects to the SPI
core, and converts the MSIOF driver to make use of this.  I expect
spi-orion can be converted, too.

Patches 3 and 4 contain two small drive-by cleanups.

on older SuperH and R-Mobile SoCs only, unfortunately, and thus
untested.  But it is too trivial not to implement ;-)

Patch 6 adds support for GPIO chip selects.

This has been tested with concurrent access to two cs-gpio slaves
connected to the two PMOD connectors on the RSK+RZA1 development board,
and regression-tested on Koelsch (single native chip select).

Thanks for your comments!

Geert Uytterhoeven (6):
  spi: Add generic support for unused native cs with cs-gpios
  spi: sh-msiof: Convert to generic unused native cs handling.
  spi: rspi: Use dev_warn_once() instead of open-coding
  spi: rspi: Remove set_config_register() macro
  spi: rspi: Add support for multiple native chip selects
  spi: rspi: Add support for GPIO chip selects

 drivers/spi/spi-rspi.c     | 21 ++++++++++-----
 drivers/spi/spi-sh-msiof.c | 53 +++-----------------------------------
 drivers/spi/spi.c          | 17 ++++++++++++
 include/linux/spi/spi.h    |  8 ++++++
 4 files changed, 42 insertions(+), 57 deletions(-)

-- 
2.17.1

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

[PATCH 1/6] spi: Add generic support for unused native cs with cs-gpios

[Geert Uytterhoeven]

Some SPI master controllers always drive a native chip select when
performing a transfer.  Hence when using both native and GPIO chip
selects, at least one native chip select must be left unused, to be
driven when performing transfers with slave devices using GPIO chip
selects.

Currently, to find an unused native chip select, SPI controller drivers
need to parse and process cs-gpios theirselves.  This is not only
duplicated in each driver that needs it, but also duplicates part of the
work done later at SPI controller registration time.  Note that this
cannot be done after spi_register_controller() returns, as at that time,
slave devices may have been probed already.

Hence add generic support to the SPI subsystem for finding an unused
native chip select.  Optionally, this unused native chip select, and all
other in-use native chip selects, can be validated against the maximum
number of native chip selects available on the controller hardware.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
Perhaps the validation is considered overkill ("DT is assumed to be
correct")?

 drivers/spi/spi.c       | 17 +++++++++++++++++
 include/linux/spi/spi.h |  8 ++++++++
 2 files changed, 25 insertions(+)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index dc453896327106a0..38b4c78df506c060 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2458,6 +2458,8 @@ static int spi_get_gpio_descs(struct spi_controller *ctlr)
 	int nb, i;
 	struct gpio_desc **cs;
 	struct device *dev = &ctlr->dev;
+	unsigned long native_cs_mask = 0;
+	unsigned int num_cs_gpios = 0;
 
 	nb = gpiod_count(dev, "cs");
 	ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
@@ -2499,7 +2501,22 @@ static int spi_get_gpio_descs(struct spi_controller *ctlr)
 			if (!gpioname)
 				return -ENOMEM;
 			gpiod_set_consumer_name(cs[i], gpioname);
+			num_cs_gpios++;
+			continue;
+		}
+
+		if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
+			dev_err(dev, "Invalid native chip select %d\n", i);
+			return -EINVAL;
 		}
+		native_cs_mask |= BIT(i);
+	}
+
+	ctlr->unused_native_cs = ffz(native_cs_mask);
+	if (num_cs_gpios && ctlr->max_native_cs &&
+	    ctlr->unused_native_cs >= ctlr->max_native_cs) {
+		dev_err(dev, "No unused native chip select available\n");
+		return -EINVAL;
 	}
 
 	return 0;
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 3a67a7e45633cf9c..6d16ba01ff5a2e20 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -423,6 +423,12 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  *	GPIO descriptors rather than using global GPIO numbers grabbed by the
  *	driver. This will fill in @cs_gpiods and @cs_gpios should not be used,
  *	and SPI devices will have the cs_gpiod assigned rather than cs_gpio.
+ * @unused_native_cs: When cs_gpiods is used, spi_register_controller() will
+ *	fill in this field with the first unused native CS, to be used by SPI
+ *	controller drivers that need to drive a native CS when using GPIO CS.
+ * @max_native_cs: When cs_gpiods is used, and this field is filled in,
+ *	spi_register_controller() will validate all native CS (including the
+ *	unused native CS) against this value.
  * @statistics: statistics for the spi_controller
  * @dma_tx: DMA transmit channel
  * @dma_rx: DMA receive channel
@@ -624,6 +630,8 @@ struct spi_controller {
 	int			*cs_gpios;
 	struct gpio_desc	**cs_gpiods;
 	bool			use_gpio_descriptors;
+	u8			unused_native_cs;
+	u8			max_native_cs;
 
 	/* statistics */
 	struct spi_statistics	statistics;
-- 
2.17.1

[PATCH 2/6] spi: sh-msiof: Convert to generic unused native cs handling.

[Geert Uytterhoeven]

Currently the MSIOF SPI driver uses custom code to handle the unused
native chip select with GPIO chip selects.
Convert the driver to use the new generic handling in the SPI core.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/spi/spi-sh-msiof.c | 53 +++-----------------------------------
 1 file changed, 3 insertions(+), 50 deletions(-)

diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index 8f134735291f14c3..b3732dc231cb4bf3 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -14,8 +14,6 @@
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
 #include <linux/err.h>
-#include <linux/gpio.h>
-#include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
@@ -55,7 +53,6 @@ struct sh_msiof_spi_priv {
 	void *rx_dma_page;
 	dma_addr_t tx_dma_addr;
 	dma_addr_t rx_dma_addr;
-	unsigned short unused_ss;
 	bool native_cs_inited;
 	bool native_cs_high;
 	bool slave_aborted;
@@ -587,7 +584,7 @@ static int sh_msiof_prepare_message(struct spi_controller *ctlr,
 
 	/* Configure pins before asserting CS */
 	if (spi->cs_gpiod) {
-		ss = p->unused_ss;
+		ss = ctlr->unused_native_cs;
 		cs_high = p->native_cs_high;
 	} else {
 		ss = spi->chip_select;
@@ -1124,46 +1121,6 @@ static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
 }
 #endif
 
-static int sh_msiof_get_cs_gpios(struct sh_msiof_spi_priv *p)
-{
-	struct device *dev = &p->pdev->dev;
-	unsigned int used_ss_mask = 0;
-	unsigned int cs_gpios = 0;
-	unsigned int num_cs, i;
-	int ret;
-
-	ret = gpiod_count(dev, "cs");
-	if (ret <= 0)
-		return 0;
-
-	num_cs = max_t(unsigned int, ret, p->ctlr->num_chipselect);
-	for (i = 0; i < num_cs; i++) {
-		struct gpio_desc *gpiod;
-
-		gpiod = devm_gpiod_get_index(dev, "cs", i, GPIOD_ASIS);
-		if (!IS_ERR(gpiod)) {
-			devm_gpiod_put(dev, gpiod);
-			cs_gpios++;
-			continue;
-		}
-
-		if (PTR_ERR(gpiod) != -ENOENT)
-			return PTR_ERR(gpiod);
-
-		if (i >= MAX_SS) {
-			dev_err(dev, "Invalid native chip select %d\n", i);
-			return -EINVAL;
-		}
-		used_ss_mask |= BIT(i);
-	}
-	p->unused_ss = ffz(used_ss_mask);
-	if (cs_gpios && p->unused_ss >= MAX_SS) {
-		dev_err(dev, "No unused native chip select available\n");
-		return -EINVAL;
-	}
-	return 0;
-}
-
 static struct dma_chan *sh_msiof_request_dma_chan(struct device *dev,
 	enum dma_transfer_direction dir, unsigned int id, dma_addr_t port_addr)
 {
@@ -1373,17 +1330,12 @@ static int sh_msiof_spi_probe(struct platform_device *pdev)
 	if (p->info->rx_fifo_override)
 		p->rx_fifo_size = p->info->rx_fifo_override;
 
-	/* Setup GPIO chip selects */
-	ctlr->num_chipselect = p->info->num_chipselect;
-	ret = sh_msiof_get_cs_gpios(p);
-	if (ret)
-		goto err1;
-
 	/* init controller code */
 	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
 	ctlr->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
 	ctlr->flags = chipdata->ctlr_flags;
 	ctlr->bus_num = pdev->id;
+	ctlr->num_chipselect = p->info->num_chipselect;
 	ctlr->dev.of_node = pdev->dev.of_node;
 	ctlr->setup = sh_msiof_spi_setup;
 	ctlr->prepare_message = sh_msiof_prepare_message;
@@ -1392,6 +1344,7 @@ static int sh_msiof_spi_probe(struct platform_device *pdev)
 	ctlr->auto_runtime_pm = true;
 	ctlr->transfer_one = sh_msiof_transfer_one;
 	ctlr->use_gpio_descriptors = true;
+	ctlr->max_native_cs = MAX_SS;
 
 	ret = sh_msiof_request_dma(p);
 	if (ret < 0)
-- 
2.17.1

[PATCH 3/6] spi: rspi: Use dev_warn_once() instead of open-coding

[Geert Uytterhoeven]

Use the helper introduced by commit e135303bd5bebcd2 ("device: Add
dev_<level>_once variants") instead of open-coding the same operation.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/spi/spi-rspi.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 74a12f4dee849125..e54a25f848ea38c7 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -620,9 +620,8 @@ static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
 		dmaengine_terminate_all(rspi->ctlr->dma_rx);
 no_dma_rx:
 	if (ret == -EAGAIN) {
-		pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
-			     dev_driver_string(&rspi->ctlr->dev),
-			     dev_name(&rspi->ctlr->dev));
+		dev_warn_once(&rspi->ctlr->dev,
+			      "DMA not available, falling back to PIO\n");
 	}
 	return ret;
 }
-- 
2.17.1

[PATCH 4/6] spi: rspi: Remove set_config_register() macro

[Geert Uytterhoeven]

The set_config_register() macro is used in a single place.
Make the code easier to read by just removing it.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/spi/spi-rspi.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index e54a25f848ea38c7..9eabef3d6cc478ff 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -426,8 +426,6 @@ static int qspi_set_receive_trigger(struct rspi_data *rspi, unsigned int len)
 	return n;
 }
 
-#define set_config_register(spi, n) spi->ops->set_config_register(spi, n)
-
 static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable)
 {
 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR);
@@ -940,7 +938,7 @@ static int rspi_prepare_message(struct spi_controller *ctlr,
 	if (spi->mode & SPI_LOOP)
 		rspi->sppcr |= SPPCR_SPLP;
 
-	set_config_register(rspi, 8);
+	rspi->ops->set_config_register(rspi, 8);
 
 	if (msg->spi->mode &
 	    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)) {
-- 
2.17.1

[PATCH 5/6] spi: rspi: Add support for multiple native chip selects

[Geert Uytterhoeven]

RSPI variants on some SuperH or R-Mobile SoCs support multiple native
chip selects. Add support for this by configuring the SSL Assert Signal
Setting.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/spi/spi-rspi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 9eabef3d6cc478ff..2f5a856a93192702 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -159,7 +159,7 @@
 #define SPCMD_SPIMOD_DUAL	SPCMD_SPIMOD0
 #define SPCMD_SPIMOD_QUAD	SPCMD_SPIMOD1
 #define SPCMD_SPRW		0x0010	/* SPI Read/Write Access (Dual/Quad) */
-#define SPCMD_SSLA_MASK		0x0030	/* SSL Assert Signal Setting (RSPI) */
+#define SPCMD_SSLA(i)		((i) << 4)	/* SSL Assert Signal Setting */
 #define SPCMD_BRDV_MASK		0x000c	/* Bit Rate Division Setting */
 #define SPCMD_CPOL		0x0002	/* Clock Polarity Setting */
 #define SPCMD_CPHA		0x0001	/* Clock Phase Setting */
@@ -933,6 +933,9 @@ static int rspi_prepare_message(struct spi_controller *ctlr,
 	if (spi->mode & SPI_CPHA)
 		rspi->spcmd |= SPCMD_CPHA;
 
+	/* Configure slave signal to assert */
+	rspi->spcmd |= SPCMD_SSLA(spi->chip_select);
+
 	/* CMOS output mode and MOSI signal from previous transfer */
 	rspi->sppcr = 0;
 	if (spi->mode & SPI_LOOP)
-- 
2.17.1

[PATCH 6/6] spi: rspi: Add support for GPIO chip selects

[Geert Uytterhoeven]

Add support for GPIO chip selects using GPIO descriptors.  As the RSPI
controller always drives a native chip select when performing a
transfer, at least one native chip select must be left unused.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/spi/spi-rspi.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 2f5a856a93192702..85575d45901cee1b 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -242,6 +242,7 @@ struct spi_ops {
 	u16 mode_bits;
 	u16 flags;
 	u16 fifo_size;
+	u8 num_hw_ss;
 };
 
 /*
@@ -934,7 +935,8 @@ static int rspi_prepare_message(struct spi_controller *ctlr,
 		rspi->spcmd |= SPCMD_CPHA;
 
 	/* Configure slave signal to assert */
-	rspi->spcmd |= SPCMD_SSLA(spi->chip_select);
+	rspi->spcmd |= SPCMD_SSLA(spi->cs_gpiod ? rspi->ctlr->unused_native_cs
+						: spi->chip_select);
 
 	/* CMOS output mode and MOSI signal from previous transfer */
 	rspi->sppcr = 0;
@@ -1123,6 +1125,7 @@ static const struct spi_ops rspi_ops = {
 	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP,
 	.flags =		SPI_CONTROLLER_MUST_TX,
 	.fifo_size =		8,
+	.num_hw_ss =		2,
 };
 
 static const struct spi_ops rspi_rz_ops = {
@@ -1131,6 +1134,7 @@ static const struct spi_ops rspi_rz_ops = {
 	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP,
 	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
 	.fifo_size =		8,	/* 8 for TX, 32 for RX */
+	.num_hw_ss =		1,
 };
 
 static const struct spi_ops qspi_ops = {
@@ -1141,6 +1145,7 @@ static const struct spi_ops qspi_ops = {
 				SPI_RX_DUAL | SPI_RX_QUAD,
 	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
 	.fifo_size =		32,
+	.num_hw_ss =		1,
 };
 
 #ifdef CONFIG_OF
@@ -1256,6 +1261,8 @@ static int rspi_probe(struct platform_device *pdev)
 	ctlr->mode_bits = ops->mode_bits;
 	ctlr->flags = ops->flags;
 	ctlr->dev.of_node = pdev->dev.of_node;
+	ctlr->use_gpio_descriptors = true;
+	ctlr->max_native_cs = rspi->ops->num_hw_ss;
 
 	ret = platform_get_irq_byname_optional(pdev, "rx");
 	if (ret < 0) {
-- 
2.17.1

Applied "spi: rspi: Add support for GPIO chip selects" to the spi tree

[Mark Brown]

The patch

   spi: rspi: Add support for GPIO chip selects

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-5.6

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

>From 144d8f9781e60d89dfd614210d2cedbefbba8885 Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Thu, 2 Jan 2020 14:38:22 +0100
Subject: [PATCH] spi: rspi: Add support for GPIO chip selects

Add support for GPIO chip selects using GPIO descriptors.  As the RSPI
controller always drives a native chip select when performing a
transfer, at least one native chip select must be left unused.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200102133822.29346-7-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi-rspi.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 2f5a856a9319..85575d45901c 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -242,6 +242,7 @@ struct spi_ops {
 	u16 mode_bits;
 	u16 flags;
 	u16 fifo_size;
+	u8 num_hw_ss;
 };
 
 /*
@@ -934,7 +935,8 @@ static int rspi_prepare_message(struct spi_controller *ctlr,
 		rspi->spcmd |= SPCMD_CPHA;
 
 	/* Configure slave signal to assert */
-	rspi->spcmd |= SPCMD_SSLA(spi->chip_select);
+	rspi->spcmd |= SPCMD_SSLA(spi->cs_gpiod ? rspi->ctlr->unused_native_cs
+						: spi->chip_select);
 
 	/* CMOS output mode and MOSI signal from previous transfer */
 	rspi->sppcr = 0;
@@ -1123,6 +1125,7 @@ static const struct spi_ops rspi_ops = {
 	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP,
 	.flags =		SPI_CONTROLLER_MUST_TX,
 	.fifo_size =		8,
+	.num_hw_ss =		2,
 };
 
 static const struct spi_ops rspi_rz_ops = {
@@ -1131,6 +1134,7 @@ static const struct spi_ops rspi_rz_ops = {
 	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP,
 	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
 	.fifo_size =		8,	/* 8 for TX, 32 for RX */
+	.num_hw_ss =		1,
 };
 
 static const struct spi_ops qspi_ops = {
@@ -1141,6 +1145,7 @@ static const struct spi_ops qspi_ops = {
 				SPI_RX_DUAL | SPI_RX_QUAD,
 	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
 	.fifo_size =		32,
+	.num_hw_ss =		1,
 };
 
 #ifdef CONFIG_OF
@@ -1256,6 +1261,8 @@ static int rspi_probe(struct platform_device *pdev)
 	ctlr->mode_bits = ops->mode_bits;
 	ctlr->flags = ops->flags;
 	ctlr->dev.of_node = pdev->dev.of_node;
+	ctlr->use_gpio_descriptors = true;
+	ctlr->max_native_cs = rspi->ops->num_hw_ss;
 
 	ret = platform_get_irq_byname_optional(pdev, "rx");
 	if (ret < 0) {
-- 
2.20.1

Applied "spi: rspi: Add support for multiple native chip selects" to the spi tree

[Mark Brown]

The patch

   spi: rspi: Add support for multiple native chip selects

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-5.6

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

>From 9815ed8714d26560d09b41f906b96a97f9bc3e3f Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Thu, 2 Jan 2020 14:38:21 +0100
Subject: [PATCH] spi: rspi: Add support for multiple native chip selects

RSPI variants on some SuperH or R-Mobile SoCs support multiple native
chip selects. Add support for this by configuring the SSL Assert Signal
Setting.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200102133822.29346-6-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi-rspi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 9eabef3d6cc4..2f5a856a9319 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -159,7 +159,7 @@
 #define SPCMD_SPIMOD_DUAL	SPCMD_SPIMOD0
 #define SPCMD_SPIMOD_QUAD	SPCMD_SPIMOD1
 #define SPCMD_SPRW		0x0010	/* SPI Read/Write Access (Dual/Quad) */
-#define SPCMD_SSLA_MASK		0x0030	/* SSL Assert Signal Setting (RSPI) */
+#define SPCMD_SSLA(i)		((i) << 4)	/* SSL Assert Signal Setting */
 #define SPCMD_BRDV_MASK		0x000c	/* Bit Rate Division Setting */
 #define SPCMD_CPOL		0x0002	/* Clock Polarity Setting */
 #define SPCMD_CPHA		0x0001	/* Clock Phase Setting */
@@ -933,6 +933,9 @@ static int rspi_prepare_message(struct spi_controller *ctlr,
 	if (spi->mode & SPI_CPHA)
 		rspi->spcmd |= SPCMD_CPHA;
 
+	/* Configure slave signal to assert */
+	rspi->spcmd |= SPCMD_SSLA(spi->chip_select);
+
 	/* CMOS output mode and MOSI signal from previous transfer */
 	rspi->sppcr = 0;
 	if (spi->mode & SPI_LOOP)
-- 
2.20.1

Applied "spi: rspi: Remove set_config_register() macro" to the spi tree

[Mark Brown]

The patch

   spi: rspi: Remove set_config_register() macro

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-5.6

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

>From 8f2344fa7f54382eeaf4b65d70c74b0b44df7a6b Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Thu, 2 Jan 2020 14:38:20 +0100
Subject: [PATCH] spi: rspi: Remove set_config_register() macro

The set_config_register() macro is used in a single place.
Make the code easier to read by just removing it.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200102133822.29346-5-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi-rspi.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index e54a25f848ea..9eabef3d6cc4 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -426,8 +426,6 @@ static int qspi_set_receive_trigger(struct rspi_data *rspi, unsigned int len)
 	return n;
 }
 
-#define set_config_register(spi, n) spi->ops->set_config_register(spi, n)
-
 static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable)
 {
 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR);
@@ -940,7 +938,7 @@ static int rspi_prepare_message(struct spi_controller *ctlr,
 	if (spi->mode & SPI_LOOP)
 		rspi->sppcr |= SPPCR_SPLP;
 
-	set_config_register(rspi, 8);
+	rspi->ops->set_config_register(rspi, 8);
 
 	if (msg->spi->mode &
 	    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)) {
-- 
2.20.1

Applied "spi: rspi: Use dev_warn_once() instead of open-coding" to the spi tree

[Mark Brown]

The patch

   spi: rspi: Use dev_warn_once() instead of open-coding

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-5.6

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

>From 1bec84ddd85ae7a2b1df5fef3a5c7e5c44cbe36e Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Thu, 2 Jan 2020 14:38:19 +0100
Subject: [PATCH] spi: rspi: Use dev_warn_once() instead of open-coding

Use the helper introduced by commit e135303bd5bebcd2 ("device: Add
dev_<level>_once variants") instead of open-coding the same operation.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200102133822.29346-4-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi-rspi.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 74a12f4dee84..e54a25f848ea 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -620,9 +620,8 @@ static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
 		dmaengine_terminate_all(rspi->ctlr->dma_rx);
 no_dma_rx:
 	if (ret == -EAGAIN) {
-		pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
-			     dev_driver_string(&rspi->ctlr->dev),
-			     dev_name(&rspi->ctlr->dev));
+		dev_warn_once(&rspi->ctlr->dev,
+			      "DMA not available, falling back to PIO\n");
 	}
 	return ret;
 }
-- 
2.20.1

Applied "spi: sh-msiof: Convert to generic unused native cs handling." to the spi tree

[Mark Brown]

The patch

   spi: sh-msiof: Convert to generic unused native cs handling.

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-5.6

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

>From aa32f76e0a409adcd40ef11ed1ed668df8b034f6 Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Thu, 2 Jan 2020 14:38:18 +0100
Subject: [PATCH] spi: sh-msiof: Convert to generic unused native cs handling.

Currently the MSIOF SPI driver uses custom code to handle the unused
native chip select with GPIO chip selects.
Convert the driver to use the new generic handling in the SPI core.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200102133822.29346-3-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi-sh-msiof.c | 53 +++-----------------------------------
 1 file changed, 3 insertions(+), 50 deletions(-)

diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index 8f134735291f..b3732dc231cb 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -14,8 +14,6 @@
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
 #include <linux/err.h>
-#include <linux/gpio.h>
-#include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
@@ -55,7 +53,6 @@ struct sh_msiof_spi_priv {
 	void *rx_dma_page;
 	dma_addr_t tx_dma_addr;
 	dma_addr_t rx_dma_addr;
-	unsigned short unused_ss;
 	bool native_cs_inited;
 	bool native_cs_high;
 	bool slave_aborted;
@@ -587,7 +584,7 @@ static int sh_msiof_prepare_message(struct spi_controller *ctlr,
 
 	/* Configure pins before asserting CS */
 	if (spi->cs_gpiod) {
-		ss = p->unused_ss;
+		ss = ctlr->unused_native_cs;
 		cs_high = p->native_cs_high;
 	} else {
 		ss = spi->chip_select;
@@ -1124,46 +1121,6 @@ static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
 }
 #endif
 
-static int sh_msiof_get_cs_gpios(struct sh_msiof_spi_priv *p)
-{
-	struct device *dev = &p->pdev->dev;
-	unsigned int used_ss_mask = 0;
-	unsigned int cs_gpios = 0;
-	unsigned int num_cs, i;
-	int ret;
-
-	ret = gpiod_count(dev, "cs");
-	if (ret <= 0)
-		return 0;
-
-	num_cs = max_t(unsigned int, ret, p->ctlr->num_chipselect);
-	for (i = 0; i < num_cs; i++) {
-		struct gpio_desc *gpiod;
-
-		gpiod = devm_gpiod_get_index(dev, "cs", i, GPIOD_ASIS);
-		if (!IS_ERR(gpiod)) {
-			devm_gpiod_put(dev, gpiod);
-			cs_gpios++;
-			continue;
-		}
-
-		if (PTR_ERR(gpiod) != -ENOENT)
-			return PTR_ERR(gpiod);
-
-		if (i >= MAX_SS) {
-			dev_err(dev, "Invalid native chip select %d\n", i);
-			return -EINVAL;
-		}
-		used_ss_mask |= BIT(i);
-	}
-	p->unused_ss = ffz(used_ss_mask);
-	if (cs_gpios && p->unused_ss >= MAX_SS) {
-		dev_err(dev, "No unused native chip select available\n");
-		return -EINVAL;
-	}
-	return 0;
-}
-
 static struct dma_chan *sh_msiof_request_dma_chan(struct device *dev,
 	enum dma_transfer_direction dir, unsigned int id, dma_addr_t port_addr)
 {
@@ -1373,17 +1330,12 @@ static int sh_msiof_spi_probe(struct platform_device *pdev)
 	if (p->info->rx_fifo_override)
 		p->rx_fifo_size = p->info->rx_fifo_override;
 
-	/* Setup GPIO chip selects */
-	ctlr->num_chipselect = p->info->num_chipselect;
-	ret = sh_msiof_get_cs_gpios(p);
-	if (ret)
-		goto err1;
-
 	/* init controller code */
 	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
 	ctlr->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
 	ctlr->flags = chipdata->ctlr_flags;
 	ctlr->bus_num = pdev->id;
+	ctlr->num_chipselect = p->info->num_chipselect;
 	ctlr->dev.of_node = pdev->dev.of_node;
 	ctlr->setup = sh_msiof_spi_setup;
 	ctlr->prepare_message = sh_msiof_prepare_message;
@@ -1392,6 +1344,7 @@ static int sh_msiof_spi_probe(struct platform_device *pdev)
 	ctlr->auto_runtime_pm = true;
 	ctlr->transfer_one = sh_msiof_transfer_one;
 	ctlr->use_gpio_descriptors = true;
+	ctlr->max_native_cs = MAX_SS;
 
 	ret = sh_msiof_request_dma(p);
 	if (ret < 0)
-- 
2.20.1

Applied "spi: Add generic support for unused native cs with cs-gpios" to the spi tree

[Mark Brown]

The patch

   spi: Add generic support for unused native cs with cs-gpios

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-5.6

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

>From 7d93aecdb58d47e8ed90b4a44c0fc9ffb8de941c Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Thu, 2 Jan 2020 14:38:17 +0100
Subject: [PATCH] spi: Add generic support for unused native cs with cs-gpios

Some SPI master controllers always drive a native chip select when
performing a transfer.  Hence when using both native and GPIO chip
selects, at least one native chip select must be left unused, to be
driven when performing transfers with slave devices using GPIO chip
selects.

Currently, to find an unused native chip select, SPI controller drivers
need to parse and process cs-gpios theirselves.  This is not only
duplicated in each driver that needs it, but also duplicates part of the
work done later at SPI controller registration time.  Note that this
cannot be done after spi_register_controller() returns, as at that time,
slave devices may have been probed already.

Hence add generic support to the SPI subsystem for finding an unused
native chip select.  Optionally, this unused native chip select, and all
other in-use native chip selects, can be validated against the maximum
number of native chip selects available on the controller hardware.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200102133822.29346-2-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi.c       | 17 +++++++++++++++++
 include/linux/spi/spi.h |  8 ++++++++
 2 files changed, 25 insertions(+)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 5485ef89197c..197c9e0ac2a6 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2464,6 +2464,8 @@ static int spi_get_gpio_descs(struct spi_controller *ctlr)
 	int nb, i;
 	struct gpio_desc **cs;
 	struct device *dev = &ctlr->dev;
+	unsigned long native_cs_mask = 0;
+	unsigned int num_cs_gpios = 0;
 
 	nb = gpiod_count(dev, "cs");
 	ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
@@ -2505,7 +2507,22 @@ static int spi_get_gpio_descs(struct spi_controller *ctlr)
 			if (!gpioname)
 				return -ENOMEM;
 			gpiod_set_consumer_name(cs[i], gpioname);
+			num_cs_gpios++;
+			continue;
+		}
+
+		if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
+			dev_err(dev, "Invalid native chip select %d\n", i);
+			return -EINVAL;
 		}
+		native_cs_mask |= BIT(i);
+	}
+
+	ctlr->unused_native_cs = ffz(native_cs_mask);
+	if (num_cs_gpios && ctlr->max_native_cs &&
+	    ctlr->unused_native_cs >= ctlr->max_native_cs) {
+		dev_err(dev, "No unused native chip select available\n");
+		return -EINVAL;
 	}
 
 	return 0;
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 98fe8663033a..e4011b852fc3 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -423,6 +423,12 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  *	GPIO descriptors rather than using global GPIO numbers grabbed by the
  *	driver. This will fill in @cs_gpiods and @cs_gpios should not be used,
  *	and SPI devices will have the cs_gpiod assigned rather than cs_gpio.
+ * @unused_native_cs: When cs_gpiods is used, spi_register_controller() will
+ *	fill in this field with the first unused native CS, to be used by SPI
+ *	controller drivers that need to drive a native CS when using GPIO CS.
+ * @max_native_cs: When cs_gpiods is used, and this field is filled in,
+ *	spi_register_controller() will validate all native CS (including the
+ *	unused native CS) against this value.
  * @statistics: statistics for the spi_controller
  * @dma_tx: DMA transmit channel
  * @dma_rx: DMA receive channel
@@ -624,6 +630,8 @@ struct spi_controller {
 	int			*cs_gpios;
 	struct gpio_desc	**cs_gpiods;
 	bool			use_gpio_descriptors;
+	u8			unused_native_cs;
+	u8			max_native_cs;
 
 	/* statistics */
 	struct spi_statistics	statistics;
-- 
2.20.1