[PATCH v3 0/5] Allwinner R329/D1/R528/T113s SPI support

[PATCH v3 0/5] Allwinner R329/D1/R528/T113s SPI support

[Maksim Kiselev]

This series is attempt to revive previous work to add support for SPI
controller which is used in newest Allwinner's SOCs R329/D1/R528/T113s
https://lore.kernel.org/lkml/BYAPR20MB2472E8B10BFEF75E7950BBC0BCF79@BYAPR20MB2472.namprd20.prod.outlook.com/

v3:
  - fixed effective_speed_hz setup and added SPI sample mode configuration
  - merged DT bindings for R329 and D1 SPI controllers
  - added SPI_DBI node to sunxi-d1s-t113.dtsi

v2:
  - added DT bindings and node for D1/T113s

Icenowy Zheng (1):
  spi: sun6i: change OF match data to a struct

Maksim Kiselev (4):
  dt-bindings: spi: sun6i: add DT bindings for Allwinner
    R329/D1/R528/T113s SPI
  spi: sun6i: add quirk for in-controller clock divider
  spi: sun6i: add support for R329/D1/R528/T113s SPI controllers
  riscv: dts: allwinner: d1: Add SPI controllers node

 .../bindings/spi/allwinner,sun6i-a31-spi.yaml |   7 +
 .../boot/dts/allwinner/sunxi-d1s-t113.dtsi    |  37 +++++
 drivers/spi/spi-sun6i.c                       | 132 ++++++++++++------
 3 files changed, 136 insertions(+), 40 deletions(-)

-- 
2.39.2

[PATCH v3 1/5] dt-bindings: spi: sun6i: add DT bindings for Allwinner R329/D1/R528/T113s SPI

[Maksim Kiselev]

Listed above Allwinner SoCs has two SPI controllers. First is the regular
SPI controller and the second one has additional functionality for
MIPI-DBI Type C.

Add compatible strings for these controllers

Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>
---
 .../devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml   | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml b/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml
index de36c6a34a0f..807dde457e3b 100644
--- a/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml
+++ b/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml
@@ -21,6 +21,7 @@ properties:
     oneOf:
       - const: allwinner,sun6i-a31-spi
       - const: allwinner,sun8i-h3-spi
+      - const: allwinner,sun50i-r329-spi
       - items:
           - enum:
               - allwinner,sun8i-r40-spi
@@ -28,6 +29,12 @@ properties:
               - allwinner,sun50i-h616-spi
               - allwinner,suniv-f1c100s-spi
           - const: allwinner,sun8i-h3-spi
+      - items:
+          - enum:
+              - allwinner,sun20i-d1-spi
+              - allwinner,sun20i-d1-spi-dbi
+              - allwinner,sun50i-r329-spi-dbi
+          - const: allwinner,sun50i-r329-spi
 
   reg:
     maxItems: 1
-- 
2.39.2

[PATCH v3 2/5] spi: sun6i: change OF match data to a struct

[Maksim Kiselev]

From: Icenowy Zheng <icenowy@aosc.io>

As we're adding more properties to the OF match data, convert it to a
struct now.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>
Reviewed-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 drivers/spi/spi-sun6i.c | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 7532c85a352c..01a01cd86db5 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -85,6 +85,10 @@
 #define SUN6I_TXDATA_REG		0x200
 #define SUN6I_RXDATA_REG		0x300
 
+struct sun6i_spi_cfg {
+	unsigned long		fifo_depth;
+};
+
 struct sun6i_spi {
 	struct spi_master	*master;
 	void __iomem		*base_addr;
@@ -99,7 +103,7 @@ struct sun6i_spi {
 	const u8		*tx_buf;
 	u8			*rx_buf;
 	int			len;
-	unsigned long		fifo_depth;
+	const struct sun6i_spi_cfg *cfg;
 };
 
 static inline u32 sun6i_spi_read(struct sun6i_spi *sspi, u32 reg)
@@ -156,7 +160,7 @@ static inline void sun6i_spi_fill_fifo(struct sun6i_spi *sspi)
 	u8 byte;
 
 	/* See how much data we can fit */
-	cnt = sspi->fifo_depth - sun6i_spi_get_tx_fifo_count(sspi);
+	cnt = sspi->cfg->fifo_depth - sun6i_spi_get_tx_fifo_count(sspi);
 
 	len = min((int)cnt, sspi->len);
 
@@ -289,14 +293,14 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 		 * the hardcoded value used in old generation of Allwinner
 		 * SPI controller. (See spi-sun4i.c)
 		 */
-		trig_level = sspi->fifo_depth / 4 * 3;
+		trig_level = sspi->cfg->fifo_depth / 4 * 3;
 	} else {
 		/*
 		 * Setup FIFO DMA request trigger level
 		 * We choose 1/2 of the full fifo depth, that value will
 		 * be used as DMA burst length.
 		 */
-		trig_level = sspi->fifo_depth / 2;
+		trig_level = sspi->cfg->fifo_depth / 2;
 
 		if (tfr->tx_buf)
 			reg |= SUN6I_FIFO_CTL_TF_DRQ_EN;
@@ -410,9 +414,9 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 	reg = SUN6I_INT_CTL_TC;
 
 	if (!use_dma) {
-		if (rx_len > sspi->fifo_depth)
+		if (rx_len > sspi->cfg->fifo_depth)
 			reg |= SUN6I_INT_CTL_RF_RDY;
-		if (tx_len > sspi->fifo_depth)
+		if (tx_len > sspi->cfg->fifo_depth)
 			reg |= SUN6I_INT_CTL_TF_ERQ;
 	}
 
@@ -543,7 +547,7 @@ static bool sun6i_spi_can_dma(struct spi_master *master,
 	 * the fifo length we can just fill the fifo and wait for a single
 	 * irq, so don't bother setting up dma
 	 */
-	return xfer->len > sspi->fifo_depth;
+	return xfer->len > sspi->cfg->fifo_depth;
 }
 
 static int sun6i_spi_probe(struct platform_device *pdev)
@@ -582,7 +586,7 @@ static int sun6i_spi_probe(struct platform_device *pdev)
 	}
 
 	sspi->master = master;
-	sspi->fifo_depth = (unsigned long)of_device_get_match_data(&pdev->dev);
+	sspi->cfg = of_device_get_match_data(&pdev->dev);
 
 	master->max_speed_hz = 100 * 1000 * 1000;
 	master->min_speed_hz = 3 * 1000;
@@ -695,9 +699,17 @@ static void sun6i_spi_remove(struct platform_device *pdev)
 		dma_release_channel(master->dma_rx);
 }
 
+static const struct sun6i_spi_cfg sun6i_a31_spi_cfg = {
+	.fifo_depth	= SUN6I_FIFO_DEPTH,
+};
+
+static const struct sun6i_spi_cfg sun8i_h3_spi_cfg = {
+	.fifo_depth	= SUN8I_FIFO_DEPTH,
+};
+
 static const struct of_device_id sun6i_spi_match[] = {
-	{ .compatible = "allwinner,sun6i-a31-spi", .data = (void *)SUN6I_FIFO_DEPTH },
-	{ .compatible = "allwinner,sun8i-h3-spi",  .data = (void *)SUN8I_FIFO_DEPTH },
+	{ .compatible = "allwinner,sun6i-a31-spi", .data = &sun6i_a31_spi_cfg },
+	{ .compatible = "allwinner,sun8i-h3-spi",  .data = &sun8i_h3_spi_cfg },
 	{}
 };
 MODULE_DEVICE_TABLE(of, sun6i_spi_match);
-- 
2.39.2

[PATCH v3 3/5] spi: sun6i: add quirk for in-controller clock divider

[Maksim Kiselev]

Previously SPI controllers in Allwinner SoCs has a clock divider inside.
However now the clock divider is removed and to set the transfer clock
rate it's only needed to set the SPI module clock to the target value
and configure a proper work mode.

According to the datasheet there are three work modes:

| SPI Sample Mode         | SDM(bit13) | SDC(bit11) | Run Clock |
|-------------------------|------------|------------|-----------|
| normal sample           |      1     |      0     | <= 24 MHz |
| delay half cycle sample |      0     |      0     | <= 40 MHz |
| delay one cycle sample  |      0     |      1     | >= 80 MHz |

Add a quirk for this kind of SPI controllers.

Co-developed-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>
---
 drivers/spi/spi-sun6i.c | 92 +++++++++++++++++++++++++++--------------
 1 file changed, 62 insertions(+), 30 deletions(-)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 01a01cd86db5..1e9e9a8159d9 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -42,7 +42,9 @@
 #define SUN6I_TFR_CTL_CS_MANUAL			BIT(6)
 #define SUN6I_TFR_CTL_CS_LEVEL			BIT(7)
 #define SUN6I_TFR_CTL_DHB			BIT(8)
+#define SUN6I_TFR_CTL_SDC			BIT(11)
 #define SUN6I_TFR_CTL_FBS			BIT(12)
+#define SUN6I_TFR_CTL_SDM			BIT(13)
 #define SUN6I_TFR_CTL_XCH			BIT(31)
 
 #define SUN6I_INT_CTL_REG		0x10
@@ -87,6 +89,7 @@
 
 struct sun6i_spi_cfg {
 	unsigned long		fifo_depth;
+	bool			has_clk_ctl;
 };
 
 struct sun6i_spi {
@@ -260,7 +263,7 @@ 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, div_cdr1, div_cdr2, timeout;
+	unsigned int div, div_cdr1, div_cdr2, timeout;
 	unsigned int start, end, tx_time;
 	unsigned int trig_level;
 	unsigned int tx_len = 0, rx_len = 0;
@@ -350,39 +353,66 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 
 	sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
 
-	/* Ensure that we have a parent clock fast enough */
-	mclk_rate = clk_get_rate(sspi->mclk);
-	if (mclk_rate < (2 * tfr->speed_hz)) {
-		clk_set_rate(sspi->mclk, 2 * tfr->speed_hz);
-		mclk_rate = clk_get_rate(sspi->mclk);
-	}
+	if (sspi->cfg->has_clk_ctl) {
+		unsigned int mclk_rate = clk_get_rate(sspi->mclk);
 
-	/*
-	 * Setup clock divider.
-	 *
-	 * We have two choices there. Either we can use the clock
-	 * divide rate 1, which is calculated thanks to this formula:
-	 * SPI_CLK = MOD_CLK / (2 ^ cdr)
-	 * Or we can use CDR2, which is calculated with the formula:
-	 * SPI_CLK = MOD_CLK / (2 * (cdr + 1))
-	 * Wether we use the former or the latter is set through the
-	 * DRS bit.
-	 *
-	 * First try CDR2, and if we can't reach the expected
-	 * frequency, fall back to CDR1.
-	 */
-	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;
-		tfr->effective_speed_hz = mclk_rate / (2 * div_cdr2);
+		/* Ensure that we have a parent clock fast enough */
+		if (mclk_rate < (2 * tfr->speed_hz)) {
+			clk_set_rate(sspi->mclk, 2 * tfr->speed_hz);
+			mclk_rate = clk_get_rate(sspi->mclk);
+		}
+
+		/*
+		 * Setup clock divider.
+		 *
+		 * We have two choices there. Either we can use the clock
+		 * divide rate 1, which is calculated thanks to this formula:
+		 * SPI_CLK = MOD_CLK / (2 ^ cdr)
+		 * Or we can use CDR2, which is calculated with the formula:
+		 * SPI_CLK = MOD_CLK / (2 * (cdr + 1))
+		 * Whether we use the former or the latter is set through the
+		 * DRS bit.
+		 *
+		 * First try CDR2, and if we can't reach the expected
+		 * frequency, fall back to CDR1.
+		 */
+		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;
+			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);
 	} 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);
+		clk_set_rate(sspi->mclk, tfr->speed_hz);
+		tfr->effective_speed_hz = clk_get_rate(sspi->mclk);
+
+		/*
+		 * Configure work mode.
+		 *
+		 * There are three work modes depending on the controller clock
+		 * frequency:
+		 * - normal sample mode           : CLK <= 24MHz SDM=1 SDC=0
+		 * - delay half-cycle sample mode : CLK <= 40MHz SDM=0 SDC=0
+		 * - delay one-cycle sample mode  : CLK >= 80MHz SDM=0 SDC=1
+		 */
+		reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
+
+		if (tfr->effective_speed_hz <= 24000000)
+			reg |= SUN6I_TFR_CTL_SDM;
+		else if (tfr->effective_speed_hz >= 80000000)
+			reg |= SUN6I_TFR_CTL_SDC;
+		else
+			reg &= ~(SUN6I_TFR_CTL_SDM | SUN6I_TFR_CTL_SDC);
+
+		sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
 	}
 
-	sun6i_spi_write(sspi, SUN6I_CLK_CTL_REG, reg);
 	/* Finally enable the bus - doing so before might raise SCK to HIGH */
 	reg = sun6i_spi_read(sspi, SUN6I_GBL_CTL_REG);
 	reg |= SUN6I_GBL_CTL_BUS_ENABLE;
@@ -701,10 +731,12 @@ static void sun6i_spi_remove(struct platform_device *pdev)
 
 static const struct sun6i_spi_cfg sun6i_a31_spi_cfg = {
 	.fifo_depth	= SUN6I_FIFO_DEPTH,
+	.has_clk_ctl	= true,
 };
 
 static const struct sun6i_spi_cfg sun8i_h3_spi_cfg = {
 	.fifo_depth	= SUN8I_FIFO_DEPTH,
+	.has_clk_ctl	= true,
 };
 
 static const struct of_device_id sun6i_spi_match[] = {
-- 
2.39.2

[PATCH v3 4/5] spi: sun6i: add support for R329/D1/R528/T113s SPI controllers

[Maksim Kiselev]

These SoCs has two SPI controllers. One of it is quite similar to previous
ones, but with internal clock divider removed; the other added MIPI DBI
Type-C offload based on the first one.

Add basical support for these controllers. As we're not going to
support the DBI functionality now, just implement the two kinds of
controllers as the same.

Co-developed-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>
---
 drivers/spi/spi-sun6i.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 1e9e9a8159d9..292fd6101283 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -739,9 +739,17 @@ static const struct sun6i_spi_cfg sun8i_h3_spi_cfg = {
 	.has_clk_ctl	= true,
 };
 
+static const struct sun6i_spi_cfg sun50i_r329_spi_cfg = {
+	.fifo_depth	= SUN8I_FIFO_DEPTH,
+};
+
 static const struct of_device_id sun6i_spi_match[] = {
 	{ .compatible = "allwinner,sun6i-a31-spi", .data = &sun6i_a31_spi_cfg },
 	{ .compatible = "allwinner,sun8i-h3-spi",  .data = &sun8i_h3_spi_cfg },
+	{
+		.compatible = "allwinner,sun50i-r329-spi",
+		.data = &sun50i_r329_spi_cfg
+	},
 	{}
 };
 MODULE_DEVICE_TABLE(of, sun6i_spi_match);
-- 
2.39.2

[PATCH v3 5/5] riscv: dts: allwinner: d1: Add SPI controllers node

[Maksim Kiselev]

Some boards form the MangoPi family (MQ\MQ-Dual\MQ-R) may have
an optional SPI flash that connects to the SPI0 controller.

This controller is the same for R329/D1/R528/T113s SoCs and
should be supported by the sun50i-r329-spi driver.

So let's add its DT nodes.

Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
---
 .../boot/dts/allwinner/sunxi-d1s-t113.dtsi    | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi b/arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi
index 922e8e0e2c09..1bb1e5cae602 100644
--- a/arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi
+++ b/arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi
@@ -108,6 +108,12 @@ rmii_pe_pins: rmii-pe-pins {
 				function = "emac";
 			};
 
+			/omit-if-no-ref/
+			spi0_pins: spi0-pins {
+				pins = "PC2", "PC3", "PC4", "PC5";
+				function = "spi0";
+			};
+
 			/omit-if-no-ref/
 			uart1_pg6_pins: uart1-pg6-pins {
 				pins = "PG6", "PG7";
@@ -447,6 +453,37 @@ mmc2: mmc@4022000 {
 			#size-cells = <0>;
 		};
 
+		spi0: spi@4025000 {
+			compatible = "allwinner,sun20i-d1-spi",
+				     "allwinner,sun50i-r329-spi";
+			reg = <0x04025000 0x1000>;
+			interrupts = <SOC_PERIPHERAL_IRQ(15) IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&ccu CLK_BUS_SPI0>, <&ccu CLK_SPI0>;
+			clock-names = "ahb", "mod";
+			dmas = <&dma 22>, <&dma 22>;
+			dma-names = "rx", "tx";
+			resets = <&ccu RST_BUS_SPI0>;
+			status = "disabled";
+			#address-cells = <1>;
+			#size-cells = <0>;
+		};
+
+		spi1: spi@4026000 {
+			compatible = "allwinner,sun20i-d1-spi-dbi",
+				     "allwinner,sun50i-r329-spi-dbi",
+				     "allwinner,sun50i-r329-spi";
+			reg = <0x04026000 0x1000>;
+			interrupts = <SOC_PERIPHERAL_IRQ(16) IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&ccu CLK_BUS_SPI1>, <&ccu CLK_SPI1>;
+			clock-names = "ahb", "mod";
+			dmas = <&dma 23>, <&dma 23>;
+			dma-names = "rx", "tx";
+			resets = <&ccu RST_BUS_SPI1>;
+			status = "disabled";
+			#address-cells = <1>;
+			#size-cells = <0>;
+		};
+
 		usb_otg: usb@4100000 {
 			compatible = "allwinner,sun20i-d1-musb",
 				     "allwinner,sun8i-a33-musb";
-- 
2.39.2

Re: [PATCH v3 1/5] dt-bindings: spi: sun6i: add DT bindings for Allwinner R329/D1/R528/T113s SPI

[Krzysztof Kozlowski]

On 07/05/2023 06:06, Icenowy Zheng wrote:
> 在 2023-05-07星期日的 02:26 +0300，Maksim Kiselev写道：
>> Listed above Allwinner SoCs has two SPI controllers. First is the
>> regular
>> SPI controller and the second one has additional functionality for
>> MIPI-DBI Type C.
>>
>> Add compatible strings for these controllers
>>
>> Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>
>> ---
>>  .../devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml   | 7
>> +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/spi/allwinner,sun6i-
>> a31-spi.yaml b/Documentation/devicetree/bindings/spi/allwinner,sun6i-
>> a31-spi.yaml
>> index de36c6a34a0f..807dde457e3b 100644
>> --- a/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-
>> spi.yaml
>> +++ b/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-
>> spi.yaml
>> @@ -21,6 +21,7 @@ properties:
>>      oneOf:
>>        - const: allwinner,sun6i-a31-spi
>>        - const: allwinner,sun8i-h3-spi
>> +      - const: allwinner,sun50i-r329-spi
>>        - items:
>>            - enum:
>>                - allwinner,sun8i-r40-spi
>> @@ -28,6 +29,12 @@ properties:
>>                - allwinner,sun50i-h616-spi
>>                - allwinner,suniv-f1c100s-spi
>>            - const: allwinner,sun8i-h3-spi
>> +      - items:
>> +          - enum:
>> +              - allwinner,sun20i-d1-spi
>> +              - allwinner,sun20i-d1-spi-dbi
> 
> In this case I will prefer to list all 4 compatibles if backward
> compatibility is used:
> "allwinner,sun20i-d1-spi-dbi", "allwinner-sun20i-d1-spi",
> "allwinner,sun50i-r329-spi-dbi", "allwinner, sun50i-r329-spi", in case
> if we were gaining support for either quirks of D1 controller or
> SPI_DBI controllers.
> 

I don't understand. If I see correctly, all four of them are specified.

Best regards,
Krzysztof

Re: [PATCH v3 1/5] dt-bindings: spi: sun6i: add DT bindings for Allwinner R329/D1/R528/T113s SPI

[Krzysztof Kozlowski]

On 07/05/2023 01:26, Maksim Kiselev wrote:
> Listed above Allwinner SoCs has two SPI controllers. First is the regular
> SPI controller and the second one has additional functionality for
> MIPI-DBI Type C.
> 
> Add compatible strings for these controllers
> 
> Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>
> ---
>  .../devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml   | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml b/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml
> index de36c6a34a0f..807dde457e3b 100644
> --- a/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml
> +++ b/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml
> @@ -21,6 +21,7 @@ properties:
>      oneOf:
>        - const: allwinner,sun6i-a31-spi
>        - const: allwinner,sun8i-h3-spi
> +      - const: allwinner,sun50i-r329-spi

Keep the list ordered.

>        - items:
>            - enum:
>                - allwinner,sun8i-r40-spi
> @@ -28,6 +29,12 @@ properties:
>                - allwinner,sun50i-h616-spi
>                - allwinner,suniv-f1c100s-spi
>            - const: allwinner,sun8i-h3-spi
> +      - items:
> +          - enum:
> +              - allwinner,sun20i-d1-spi
> +              - allwinner,sun20i-d1-spi-dbi
> +              - allwinner,sun50i-r329-spi-dbi
> +          - const: allwinner,sun50i-r329-spi


Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH v3 1/5] dt-bindings: spi: sun6i: add DT bindings for Allwinner R329/D1/R528/T113s SPI

[Andre Przywara]

On Sun, 07 May 2023 12:06:58 +0800
Icenowy Zheng <icenowy@aosc.io> wrote:

Hi,

> 在 2023-05-07星期日的 02:26 +0300，Maksim Kiselev写道：
> > Listed above Allwinner SoCs has two SPI controllers. First is the
> > regular
> > SPI controller and the second one has additional functionality for
> > MIPI-DBI Type C.
> > 
> > Add compatible strings for these controllers
> > 
> > Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>
> > ---
> >  .../devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml   | 7
> > +++++++
> >  1 file changed, 7 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/spi/allwinner,sun6i-
> > a31-spi.yaml b/Documentation/devicetree/bindings/spi/allwinner,sun6i-
> > a31-spi.yaml
> > index de36c6a34a0f..807dde457e3b 100644
> > --- a/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-
> > spi.yaml
> > +++ b/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-
> > spi.yaml
> > @@ -21,6 +21,7 @@ properties:
> >      oneOf:
> >        - const: allwinner,sun6i-a31-spi
> >        - const: allwinner,sun8i-h3-spi
> > +      - const: allwinner,sun50i-r329-spi
> >        - items:
> >            - enum:
> >                - allwinner,sun8i-r40-spi
> > @@ -28,6 +29,12 @@ properties:
> >                - allwinner,sun50i-h616-spi
> >                - allwinner,suniv-f1c100s-spi
> >            - const: allwinner,sun8i-h3-spi
> > +      - items:
> > +          - enum:
> > +              - allwinner,sun20i-d1-spi
> > +              - allwinner,sun20i-d1-spi-dbi  

This construct doesn't cover the three compatible string case, since we
only get to choose from one of the enums, and always have two strings -
hence my challenge to find the shortest sequence ;-)

> In this case I will prefer to list all 4 compatibles if backward
> compatibility is used:
> "allwinner,sun20i-d1-spi-dbi", "allwinner-sun20i-d1-spi",
> "allwinner,sun50i-r329-spi-dbi", "allwinner, sun50i-r329-spi", in case
> if we were gaining support for either quirks of D1 controller or
> SPI_DBI controllers.

I see where you are coming from, but that order doesn't look right,
since we go back from DBI to normal and then back again. And
"allwinner-sun20i-d1-spi" is not a super set of
"allwinner,sun50i-r329-spi-dbi".
In case we will need a D1 quirk, we could key this to the D1 DBI
compatible as well, I think, so this three string version should work.

Cheers,
Andre

> 
> > +              - allwinner,sun50i-r329-spi-dbi
> > +          - const: allwinner,sun50i-r329-spi
> >  
> >    reg:
> >      maxItems: 1  
> 

Re: [PATCH v3 3/5] spi: sun6i: add quirk for in-controller clock divider

[Andre Przywara]

On Sun,  7 May 2023 02:26:06 +0300
Maksim Kiselev <bigunclemax@gmail.com> wrote:

Hi Maksim,

thanks for the quick turnaround and the changes.

> Previously SPI controllers in Allwinner SoCs has a clock divider inside.
> However now the clock divider is removed and to set the transfer clock
> rate it's only needed to set the SPI module clock to the target value
> and configure a proper work mode.
> 
> According to the datasheet there are three work modes:
> 
> | SPI Sample Mode         | SDM(bit13) | SDC(bit11) | Run Clock |
> |-------------------------|------------|------------|-----------|
> | normal sample           |      1     |      0     | <= 24 MHz |
> | delay half cycle sample |      0     |      0     | <= 40 MHz |
> | delay one cycle sample  |      0     |      1     | >= 80 MHz |
> 
> Add a quirk for this kind of SPI controllers.
> 
> Co-developed-by: Icenowy Zheng <icenowy@aosc.io>
> Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>
> ---
>  drivers/spi/spi-sun6i.c | 92 +++++++++++++++++++++++++++--------------
>  1 file changed, 62 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
> index 01a01cd86db5..1e9e9a8159d9 100644
> --- a/drivers/spi/spi-sun6i.c
> +++ b/drivers/spi/spi-sun6i.c
> @@ -42,7 +42,9 @@
>  #define SUN6I_TFR_CTL_CS_MANUAL			BIT(6)
>  #define SUN6I_TFR_CTL_CS_LEVEL			BIT(7)
>  #define SUN6I_TFR_CTL_DHB			BIT(8)
> +#define SUN6I_TFR_CTL_SDC			BIT(11)
>  #define SUN6I_TFR_CTL_FBS			BIT(12)
> +#define SUN6I_TFR_CTL_SDM			BIT(13)
>  #define SUN6I_TFR_CTL_XCH			BIT(31)
>  
>  #define SUN6I_INT_CTL_REG		0x10
> @@ -87,6 +89,7 @@
>  
>  struct sun6i_spi_cfg {
>  	unsigned long		fifo_depth;
> +	bool			has_clk_ctl;
>  };
>  
>  struct sun6i_spi {
> @@ -260,7 +263,7 @@ 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, div_cdr1, div_cdr2, timeout;
> +	unsigned int div, div_cdr1, div_cdr2, timeout;
>  	unsigned int start, end, tx_time;
>  	unsigned int trig_level;
>  	unsigned int tx_len = 0, rx_len = 0;
> @@ -350,39 +353,66 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
>  
>  	sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
>  
> -	/* Ensure that we have a parent clock fast enough */
> -	mclk_rate = clk_get_rate(sspi->mclk);
> -	if (mclk_rate < (2 * tfr->speed_hz)) {
> -		clk_set_rate(sspi->mclk, 2 * tfr->speed_hz);
> -		mclk_rate = clk_get_rate(sspi->mclk);
> -	}
> +	if (sspi->cfg->has_clk_ctl) {
> +		unsigned int mclk_rate = clk_get_rate(sspi->mclk);
>  
> -	/*
> -	 * Setup clock divider.
> -	 *
> -	 * We have two choices there. Either we can use the clock
> -	 * divide rate 1, which is calculated thanks to this formula:
> -	 * SPI_CLK = MOD_CLK / (2 ^ cdr)
> -	 * Or we can use CDR2, which is calculated with the formula:
> -	 * SPI_CLK = MOD_CLK / (2 * (cdr + 1))
> -	 * Wether we use the former or the latter is set through the
> -	 * DRS bit.
> -	 *
> -	 * First try CDR2, and if we can't reach the expected
> -	 * frequency, fall back to CDR1.
> -	 */
> -	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;
> -		tfr->effective_speed_hz = mclk_rate / (2 * div_cdr2);
> +		/* Ensure that we have a parent clock fast enough */
> +		if (mclk_rate < (2 * tfr->speed_hz)) {
> +			clk_set_rate(sspi->mclk, 2 * tfr->speed_hz);
> +			mclk_rate = clk_get_rate(sspi->mclk);
> +		}
> +
> +		/*
> +		 * Setup clock divider.
> +		 *
> +		 * We have two choices there. Either we can use the clock
> +		 * divide rate 1, which is calculated thanks to this formula:
> +		 * SPI_CLK = MOD_CLK / (2 ^ cdr)
> +		 * Or we can use CDR2, which is calculated with the formula:
> +		 * SPI_CLK = MOD_CLK / (2 * (cdr + 1))
> +		 * Whether we use the former or the latter is set through the
> +		 * DRS bit.
> +		 *
> +		 * First try CDR2, and if we can't reach the expected
> +		 * frequency, fall back to CDR1.
> +		 */
> +		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;
> +			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);
>  	} 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);
> +		clk_set_rate(sspi->mclk, tfr->speed_hz);
> +		tfr->effective_speed_hz = clk_get_rate(sspi->mclk);
> +
> +		/*
> +		 * Configure work mode.
> +		 *
> +		 * There are three work modes depending on the controller clock
> +		 * frequency:
> +		 * - normal sample mode           : CLK <= 24MHz SDM=1 SDC=0
> +		 * - delay half-cycle sample mode : CLK <= 40MHz SDM=0 SDC=0
> +		 * - delay one-cycle sample mode  : CLK >= 80MHz SDM=0 SDC=1
> +		 */
> +		reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
> +
> +		if (tfr->effective_speed_hz <= 24000000)
> +			reg |= SUN6I_TFR_CTL_SDM;
> +		else if (tfr->effective_speed_hz >= 80000000)
> +			reg |= SUN6I_TFR_CTL_SDC;

This case assumes that the SDM bit is zero already. I think just
masking both bits off above, right after the read, is the easiest, then
you can also lose the else branch below entirely.

Cheers,
Andre

> +		else
> +			reg &= ~(SUN6I_TFR_CTL_SDM | SUN6I_TFR_CTL_SDC);
> +
> +		sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
>  	}
>  
> -	sun6i_spi_write(sspi, SUN6I_CLK_CTL_REG, reg);
>  	/* Finally enable the bus - doing so before might raise SCK to HIGH */
>  	reg = sun6i_spi_read(sspi, SUN6I_GBL_CTL_REG);
>  	reg |= SUN6I_GBL_CTL_BUS_ENABLE;
> @@ -701,10 +731,12 @@ static void sun6i_spi_remove(struct platform_device *pdev)
>  
>  static const struct sun6i_spi_cfg sun6i_a31_spi_cfg = {
>  	.fifo_depth	= SUN6I_FIFO_DEPTH,
> +	.has_clk_ctl	= true,
>  };
>  
>  static const struct sun6i_spi_cfg sun8i_h3_spi_cfg = {
>  	.fifo_depth	= SUN8I_FIFO_DEPTH,
> +	.has_clk_ctl	= true,
>  };
>  
>  static const struct of_device_id sun6i_spi_match[] = {

Re: [PATCH v3 4/5] spi: sun6i: add support for R329/D1/R528/T113s SPI controllers

[Andre Przywara]

On Sun,  7 May 2023 02:26:07 +0300
Maksim Kiselev <bigunclemax@gmail.com> wrote:

> These SoCs has two SPI controllers. One of it is quite similar to previous
> ones, but with internal clock divider removed; the other added MIPI DBI
> Type-C offload based on the first one.
> 
> Add basical support for these controllers. As we're not going to
> support the DBI functionality now, just implement the two kinds of
> controllers as the same.
> 
> Co-developed-by: Icenowy Zheng <icenowy@aosc.io>
> Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>

Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Cheers,
Andre

> ---
>  drivers/spi/spi-sun6i.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
> index 1e9e9a8159d9..292fd6101283 100644
> --- a/drivers/spi/spi-sun6i.c
> +++ b/drivers/spi/spi-sun6i.c
> @@ -739,9 +739,17 @@ static const struct sun6i_spi_cfg sun8i_h3_spi_cfg = {
>  	.has_clk_ctl	= true,
>  };
>  
> +static const struct sun6i_spi_cfg sun50i_r329_spi_cfg = {
> +	.fifo_depth	= SUN8I_FIFO_DEPTH,
> +};
> +
>  static const struct of_device_id sun6i_spi_match[] = {
>  	{ .compatible = "allwinner,sun6i-a31-spi", .data = &sun6i_a31_spi_cfg },
>  	{ .compatible = "allwinner,sun8i-h3-spi",  .data = &sun8i_h3_spi_cfg },
> +	{
> +		.compatible = "allwinner,sun50i-r329-spi",
> +		.data = &sun50i_r329_spi_cfg
> +	},
>  	{}
>  };
>  MODULE_DEVICE_TABLE(of, sun6i_spi_match);

Re: [PATCH v3 5/5] riscv: dts: allwinner: d1: Add SPI controllers node

[Andre Przywara]

On Sun,  7 May 2023 02:26:08 +0300
Maksim Kiselev <bigunclemax@gmail.com> wrote:

> Some boards form the MangoPi family (MQ\MQ-Dual\MQ-R) may have
> an optional SPI flash that connects to the SPI0 controller.
> 
> This controller is the same for R329/D1/R528/T113s SoCs and
> should be supported by the sun50i-r329-spi driver.
> 
> So let's add its DT nodes.
> 
> Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>
> Acked-by: Conor Dooley <conor.dooley@microchip.com>

Looks alright, thanks for the changes:

Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Cheers,
Andre

> ---
>  .../boot/dts/allwinner/sunxi-d1s-t113.dtsi    | 37 +++++++++++++++++++
>  1 file changed, 37 insertions(+)
> 
> diff --git a/arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi b/arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi
> index 922e8e0e2c09..1bb1e5cae602 100644
> --- a/arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi
> +++ b/arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi
> @@ -108,6 +108,12 @@ rmii_pe_pins: rmii-pe-pins {
>  				function = "emac";
>  			};
>  
> +			/omit-if-no-ref/
> +			spi0_pins: spi0-pins {
> +				pins = "PC2", "PC3", "PC4", "PC5";
> +				function = "spi0";
> +			};
> +
>  			/omit-if-no-ref/
>  			uart1_pg6_pins: uart1-pg6-pins {
>  				pins = "PG6", "PG7";
> @@ -447,6 +453,37 @@ mmc2: mmc@4022000 {
>  			#size-cells = <0>;
>  		};
>  
> +		spi0: spi@4025000 {
> +			compatible = "allwinner,sun20i-d1-spi",
> +				     "allwinner,sun50i-r329-spi";
> +			reg = <0x04025000 0x1000>;
> +			interrupts = <SOC_PERIPHERAL_IRQ(15) IRQ_TYPE_LEVEL_HIGH>;
> +			clocks = <&ccu CLK_BUS_SPI0>, <&ccu CLK_SPI0>;
> +			clock-names = "ahb", "mod";
> +			dmas = <&dma 22>, <&dma 22>;
> +			dma-names = "rx", "tx";
> +			resets = <&ccu RST_BUS_SPI0>;
> +			status = "disabled";
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +		};
> +
> +		spi1: spi@4026000 {
> +			compatible = "allwinner,sun20i-d1-spi-dbi",
> +				     "allwinner,sun50i-r329-spi-dbi",
> +				     "allwinner,sun50i-r329-spi";
> +			reg = <0x04026000 0x1000>;
> +			interrupts = <SOC_PERIPHERAL_IRQ(16) IRQ_TYPE_LEVEL_HIGH>;
> +			clocks = <&ccu CLK_BUS_SPI1>, <&ccu CLK_SPI1>;
> +			clock-names = "ahb", "mod";
> +			dmas = <&dma 23>, <&dma 23>;
> +			dma-names = "rx", "tx";
> +			resets = <&ccu RST_BUS_SPI1>;
> +			status = "disabled";
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +		};
> +
>  		usb_otg: usb@4100000 {
>  			compatible = "allwinner,sun20i-d1-musb",
>  				     "allwinner,sun8i-a33-musb";

Re: [PATCH v3 3/5] spi: sun6i: add quirk for in-controller clock divider

[Maxim Kiselev]

> This case assumes that the SDM bit is zero already. I think just
> masking both bits off above, right after the read, is the easiest, then
> you can also lose the else branch below entirely.

Thanks for this remark. I fixed it in the next revision.

RE: [PATCH v3 2/5] spi: sun6i: change OF match data to a struct

[David Laight]

From: Maksim Kiselev
> Sent: 07 May 2023 00:26
> 
> As we're adding more properties to the OF match data, convert it to a
> struct now.
> 
...
> -	sspi->fifo_depth = (unsigned long)of_device_get_match_data(&pdev->dev);
> +	sspi->cfg = of_device_get_match_data(&pdev->dev);

Is it worth doing a structure copy at this point?
The 'cfg' data is short and constant and it would make
the code that uses it smaller and faster.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: [PATCH v3 2/5] spi: sun6i: change OF match data to a struct

[Maxim Kiselev]

Hi, David

> Is it worth doing a structure copy at this point?
> The 'cfg' data is short and constant and it would make
> the code that uses it smaller and faster.

I'm sorry but I don't fully understand what you are suggesting.
In patch 3\5 we extend the sun6i_spi_cfg structure with the has_clk_ctl field.

пн, 8 мая 2023 г. в 12:47, David Laight <David.Laight@aculab.com>:
>
> From: Maksim Kiselev
> > Sent: 07 May 2023 00:26
> >
> > As we're adding more properties to the OF match data, convert it to a
> > struct now.
> >
> ...
> > -     sspi->fifo_depth = (unsigned long)of_device_get_match_data(&pdev->dev);
> > +     sspi->cfg = of_device_get_match_data(&pdev->dev);
>
> Is it worth doing a structure copy at this point?
> The 'cfg' data is short and constant and it would make
> the code that uses it smaller and faster.
>
>         David
>
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)
>

RE: [PATCH v3 2/5] spi: sun6i: change OF match data to a struct

[David Laight]

From: Maxim Kiselev
> Sent: 10 May 2023 09:34
> 
> Hi, David
> 
> > Is it worth doing a structure copy at this point?
> > The 'cfg' data is short and constant and it would make
> > the code that uses it smaller and faster.
> 
> I'm sorry but I don't fully understand what you are suggesting.
> In patch 3\5 we extend the sun6i_spi_cfg structure with the has_clk_ctl field.

You are still only adding a second integer.

I'm suggesting that instead of sspi->cfg being a pointer to the
config data it is a copy of the config data.
So the assignment below becomes (ignoring error checks)
	memcpy(&sspi->cfg, of_device_get_match_data(&pdev->dev), sizeof sspi->cfg);
and the code that needs the values is:
	sspi->cfg.fifo_depth
(etc)

	David

> 
> пн, 8 мая 2023 г. в 12:47, David Laight <David.Laight@aculab.com>:
> >
> > From: Maksim Kiselev
> > > Sent: 07 May 2023 00:26
> > >
> > > As we're adding more properties to the OF match data, convert it to a
> > > struct now.
> > >
> > ...
> > > -     sspi->fifo_depth = (unsigned long)of_device_get_match_data(&pdev->dev);
> > > +     sspi->cfg = of_device_get_match_data(&pdev->dev);
> >
> > Is it worth doing a structure copy at this point?
> > The 'cfg' data is short and constant and it would make
> > the code that uses it smaller and faster.
> >
> >         David
> >
> > -
> > Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> > Registration No: 1397386 (Wales)
> >

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: [PATCH v3 2/5] spi: sun6i: change OF match data to a struct

[Andre Przywara]

On Wed, 10 May 2023 08:55:27 +0000
David Laight <David.Laight@ACULAB.COM> wrote:

Hi David,

> From: Maxim Kiselev
> > Sent: 10 May 2023 09:34
> > 
> > Hi, David
> >   
> > > Is it worth doing a structure copy at this point?
> > > The 'cfg' data is short and constant and it would make

Sorry, I don't really get the reason for this. Since the data is constant,
wouldn't it make much more sense to keep it there in the const section,
which we need anyway? What would a second copy bring us?

> > > the code that uses it smaller and faster.  

Smaller: Do you mean the generated code? Not sure that really matters, but
your sketch below hints that the C code would get larger, more error prone
(you mention yourself that you skipped over the error checking) and most
importantly harder to read.

Faster: Do you have numbers that back that up, or does that solve a
particular problem of yours?
This is programming a SPI controller transfer, which runs in the vicinity
of a few Mbits/s. I doubt that saving a few memory accesses (once
per transfer, not per word) matters even the slightest?
The actual MMIO access to program the controller registers already takes
a few dozen to a few hundred cycles, so I doubt that doing a struct copy
saves us anything here, in practice.

Besides: Copying the pointer is the most common pattern in the kernel, I
believe. I just sampled 21 SPI drivers in the tree, 17 out of them do
this. The other either copy the members of the struct into the driver data
(which would be an option for us, too), or immediately consume the data in
the probe() routine.

If you have some good reason to optimise this, please send a patch (on
top).

Cheers,
Andre.

> > 
> > I'm sorry but I don't fully understand what you are suggesting.
> > In patch 3\5 we extend the sun6i_spi_cfg structure with the has_clk_ctl field.  
> 
> You are still only adding a second integer.
> 
> I'm suggesting that instead of sspi->cfg being a pointer to the
> config data it is a copy of the config data.
> So the assignment below becomes (ignoring error checks)
> 	memcpy(&sspi->cfg, of_device_get_match_data(&pdev->dev), sizeof sspi->cfg);
> and the code that needs the values is:
> 	sspi->cfg.fifo_depth
> (etc)
> 
> 	David
> 
> > 
> > пн, 8 мая 2023 г. в 12:47, David Laight <David.Laight@aculab.com>:  
> > >
> > > From: Maksim Kiselev  
> > > > Sent: 07 May 2023 00:26
> > > >
> > > > As we're adding more properties to the OF match data, convert it to a
> > > > struct now.
> > > >  
> > > ...  
> > > > -     sspi->fifo_depth = (unsigned long)of_device_get_match_data(&pdev->dev);
> > > > +     sspi->cfg = of_device_get_match_data(&pdev->dev);  
> > >
> > > Is it worth doing a structure copy at this point?
> > > The 'cfg' data is short and constant and it would make
> > > the code that uses it smaller and faster.
> > >
> > >         David
> > >
> > > -
> > > Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> > > Registration No: 1397386 (Wales)
> > >  
> 
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)