[PATCH 0/7] spi:dw: Add support for Intel Keem Bay SPI

[PATCH 0/7] spi:dw: Add support for Intel Keem Bay SPI

[Wan Ahmad Zainie]

This patchset adds support for DesignWare DWC_ssi. This soft IP
is an AMBA version 2.0-compliant AHB slave device. Existing driver
already supports the older APB version.

Intel Keem Bay SPI controller is using this IP. This patchset is
tested on Keem Bay evaluation module board.

Wan Ahmad Zainie (7):
  spi: dw: Fix typo in few registers name
  spi: dw: Add update_cr0() callback to update CTRLR0
  dt-bindings: spi: dw-apb-ssi: Convert bindings to json-schema
  dt-bindings: spi: dw-apb-ssi: Add compatible string for DesignWare
    DWC_ssi
  spi: dw: Add support for DesignWare DWC_ssi
  dt-bindings: spi: dw-apb-ssi: Add Intel Keem Bay support
  spi: dw: Add support for Intel Keem Bay SPI

 .../bindings/spi/snps,dw-apb-ssi.txt          |  41 ------
 .../bindings/spi/snps,dw-apb-ssi.yaml         | 106 +++++++++++++++
 drivers/spi/spi-dw-mid.c                      |   4 +
 drivers/spi/spi-dw-mmio.c                     |  57 +++++++-
 drivers/spi/spi-dw.c                          | 125 +++++++++++++-----
 drivers/spi/spi-dw.h                          |  25 +++-
 6 files changed, 277 insertions(+), 81 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
 create mode 100644 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml

-- 
2.17.1

[PATCH 1/7] spi: dw: Fix typo in few registers name

[Wan Ahmad Zainie]

This patch will fix typo in the register name used in the source code,
to be consistent with the register name used in the databook.

Databook: DW_apb_ssi_databook.pdf version 4.01a

Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/spi/spi-dw.c | 18 +++++++++---------
 drivers/spi/spi-dw.h |  8 ++++----
 2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index 31e3f866d11a..fbbafb099571 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -50,9 +50,9 @@ static ssize_t dw_spi_show_regs(struct file *file, char __user *user_buf,
 	len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
 			"=================================\n");
 	len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
-			"CTRL0: \t\t0x%08x\n", dw_readl(dws, DW_SPI_CTRL0));
+			"CTRLR0: \t0x%08x\n", dw_readl(dws, DW_SPI_CTRLR0));
 	len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
-			"CTRL1: \t\t0x%08x\n", dw_readl(dws, DW_SPI_CTRL1));
+			"CTRLR1: \t0x%08x\n", dw_readl(dws, DW_SPI_CTRLR1));
 	len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
 			"SSIENR: \t0x%08x\n", dw_readl(dws, DW_SPI_SSIENR));
 	len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
@@ -60,9 +60,9 @@ static ssize_t dw_spi_show_regs(struct file *file, char __user *user_buf,
 	len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
 			"BAUDR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_BAUDR));
 	len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
-			"TXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_TXFLTR));
+			"TXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_TXFTLR));
 	len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
-			"RXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_RXFLTR));
+			"RXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_RXFTLR));
 	len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
 			"TXFLR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_TXFLR));
 	len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
@@ -340,7 +340,7 @@ static int dw_spi_transfer_one(struct spi_controller *master,
 		cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
 	}
 
-	dw_writel(dws, DW_SPI_CTRL0, cr0);
+	dw_writel(dws, DW_SPI_CTRLR0, cr0);
 
 	/* Check if current transfer is a DMA transaction */
 	if (master->can_dma && master->can_dma(master, spi, transfer))
@@ -361,7 +361,7 @@ static int dw_spi_transfer_one(struct spi_controller *master,
 		}
 	} else if (!chip->poll_mode) {
 		txlevel = min_t(u16, dws->fifo_len / 2, dws->len / dws->n_bytes);
-		dw_writel(dws, DW_SPI_TXFLTR, txlevel);
+		dw_writel(dws, DW_SPI_TXFTLR, txlevel);
 
 		/* Set the interrupt mask */
 		imask |= SPI_INT_TXEI | SPI_INT_TXOI |
@@ -452,11 +452,11 @@ static void spi_hw_init(struct device *dev, struct dw_spi *dws)
 		u32 fifo;
 
 		for (fifo = 1; fifo < 256; fifo++) {
-			dw_writel(dws, DW_SPI_TXFLTR, fifo);
-			if (fifo != dw_readl(dws, DW_SPI_TXFLTR))
+			dw_writel(dws, DW_SPI_TXFTLR, fifo);
+			if (fifo != dw_readl(dws, DW_SPI_TXFTLR))
 				break;
 		}
-		dw_writel(dws, DW_SPI_TXFLTR, 0);
+		dw_writel(dws, DW_SPI_TXFTLR, 0);
 
 		dws->fifo_len = (fifo == 1) ? 0 : fifo;
 		dev_dbg(dev, "Detected FIFO size: %u bytes\n", dws->fifo_len);
diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
index 1bf5713e047d..445362c23fde 100644
--- a/drivers/spi/spi-dw.h
+++ b/drivers/spi/spi-dw.h
@@ -6,14 +6,14 @@
 #include <linux/scatterlist.h>
 
 /* Register offsets */
-#define DW_SPI_CTRL0			0x00
-#define DW_SPI_CTRL1			0x04
+#define DW_SPI_CTRLR0			0x00
+#define DW_SPI_CTRLR1			0x04
 #define DW_SPI_SSIENR			0x08
 #define DW_SPI_MWCR			0x0c
 #define DW_SPI_SER			0x10
 #define DW_SPI_BAUDR			0x14
-#define DW_SPI_TXFLTR			0x18
-#define DW_SPI_RXFLTR			0x1c
+#define DW_SPI_TXFTLR			0x18
+#define DW_SPI_RXFTLR			0x1c
 #define DW_SPI_TXFLR			0x20
 #define DW_SPI_RXFLR			0x24
 #define DW_SPI_SR			0x28
-- 
2.17.1

[PATCH 2/7] spi: dw: Add update_cr0() callback to update CTRLR0

[Wan Ahmad Zainie]

This patch adds update_cr0() callback, in struct dw_spi.

Existing code that configure register CTRLR0 is moved into a new
function, dw_spi_update_cr0(), and this will be the default.

Suggested-by: Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/spi/spi-dw-mid.c  |  4 +++
 drivers/spi/spi-dw-mmio.c | 21 +++++++++++--
 drivers/spi/spi-dw.c      | 66 +++++++++++++++++++++++++--------------
 drivers/spi/spi-dw.h      |  5 +++
 4 files changed, 69 insertions(+), 27 deletions(-)

diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index 0d86c37e0aeb..9cc010e9737e 100644
--- a/drivers/spi/spi-dw-mid.c
+++ b/drivers/spi/spi-dw-mid.c
@@ -318,5 +318,9 @@ int dw_spi_mid_init(struct dw_spi *dws)
 	dws->dma_rx = &mid_dma_rx;
 	dws->dma_ops = &mid_dma_ops;
 #endif
+
+	/* Register hook to configure CTRLR0 */
+	dws->update_cr0 = dw_spi_update_cr0;
+
 	return 0;
 }
diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
index 384a3ab6dc2d..a52f75e22109 100644
--- a/drivers/spi/spi-dw-mmio.c
+++ b/drivers/spi/spi-dw-mmio.c
@@ -106,6 +106,9 @@ static int dw_spi_mscc_init(struct platform_device *pdev,
 	dwsmmio->dws.set_cs = dw_spi_mscc_set_cs;
 	dwsmmio->priv = dwsmscc;
 
+	/* Register hook to configure CTRLR0 */
+	dwsmmio->dws.update_cr0 = dw_spi_update_cr0;
+
 	return 0;
 }
 
@@ -128,6 +131,18 @@ static int dw_spi_alpine_init(struct platform_device *pdev,
 {
 	dwsmmio->dws.cs_override = 1;
 
+	/* Register hook to configure CTRLR0 */
+	dwsmmio->dws.update_cr0 = dw_spi_update_cr0;
+
+	return 0;
+}
+
+static int dw_spi_dw_apb_init(struct platform_device *pdev,
+			      struct dw_spi_mmio *dwsmmio)
+{
+	/* Register hook to configure CTRLR0 */
+	dwsmmio->dws.update_cr0 = dw_spi_update_cr0;
+
 	return 0;
 }
 
@@ -224,17 +239,17 @@ static int dw_spi_mmio_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id dw_spi_mmio_of_match[] = {
-	{ .compatible = "snps,dw-apb-ssi", },
+	{ .compatible = "snps,dw-apb-ssi", .data = dw_spi_dw_apb_init},
 	{ .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_ocelot_init},
 	{ .compatible = "mscc,jaguar2-spi", .data = dw_spi_mscc_jaguar2_init},
 	{ .compatible = "amazon,alpine-dw-apb-ssi", .data = dw_spi_alpine_init},
-	{ .compatible = "renesas,rzn1-spi", },
+	{ .compatible = "renesas,rzn1-spi", .data = dw_spi_dw_apb_init},
 	{ /* end of table */}
 };
 MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
 
 static const struct acpi_device_id dw_spi_mmio_acpi_match[] = {
-	{"HISI0173", 0},
+	{"HISI0173", (kernel_ulong_t)dw_spi_dw_apb_init},
 	{},
 };
 MODULE_DEVICE_TABLE(acpi, dw_spi_mmio_acpi_match);
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index fbbafb099571..b475fd32f39a 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -277,6 +277,47 @@ static int poll_transfer(struct dw_spi *dws)
 	return 0;
 }
 
+static u8 dw_spi_update_tmode(struct dw_spi *dws)
+{
+	if (!dws->tx)
+		return SPI_TMOD_RO;
+	if (!dws->rx)
+		return SPI_TMOD_TO;
+
+	return SPI_TMOD_TR;
+}
+
+/* Configure CTRLR0 for DW_apb_ssi */
+u32 dw_spi_update_cr0(struct spi_controller *master, struct spi_device *spi,
+		      struct spi_transfer *transfer)
+{
+	struct dw_spi *dws = spi_controller_get_devdata(master);
+	struct chip_data *chip = spi_get_ctldata(spi);
+	u32 cr0;
+
+	/* Default SPI mode is SCPOL = 0, SCPH = 0 */
+	cr0 = (transfer->bits_per_word - 1)
+		| (chip->type << SPI_FRF_OFFSET)
+		| ((((spi->mode & SPI_CPOL) ? 1 : 0) << SPI_SCOL_OFFSET) |
+		   (((spi->mode & SPI_CPHA) ? 1 : 0) << SPI_SCPH_OFFSET) |
+		   (((spi->mode & SPI_LOOP) ? 1 : 0) << SPI_SRL_OFFSET))
+		| (chip->tmode << SPI_TMOD_OFFSET);
+
+	/*
+	 * Adjust transfer mode if necessary. Requires platform dependent
+	 * chipselect mechanism.
+	 */
+	if (chip->cs_control) {
+		chip->tmode = dw_spi_update_tmode(dws);
+
+		cr0 &= ~SPI_TMOD_MASK;
+		cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
+	}
+
+	return cr0;
+}
+EXPORT_SYMBOL_GPL(dw_spi_update_cr0);
+
 static int dw_spi_transfer_one(struct spi_controller *master,
 		struct spi_device *spi, struct spi_transfer *transfer)
 {
@@ -316,30 +357,7 @@ static int dw_spi_transfer_one(struct spi_controller *master,
 	dws->n_bytes = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);
 	dws->dma_width = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);
 
-	/* Default SPI mode is SCPOL = 0, SCPH = 0 */
-	cr0 = (transfer->bits_per_word - 1)
-		| (chip->type << SPI_FRF_OFFSET)
-		| ((((spi->mode & SPI_CPOL) ? 1 : 0) << SPI_SCOL_OFFSET) |
-			(((spi->mode & SPI_CPHA) ? 1 : 0) << SPI_SCPH_OFFSET) |
-			(((spi->mode & SPI_LOOP) ? 1 : 0) << SPI_SRL_OFFSET))
-		| (chip->tmode << SPI_TMOD_OFFSET);
-
-	/*
-	 * Adjust transfer mode if necessary. Requires platform dependent
-	 * chipselect mechanism.
-	 */
-	if (chip->cs_control) {
-		if (dws->rx && dws->tx)
-			chip->tmode = SPI_TMOD_TR;
-		else if (dws->rx)
-			chip->tmode = SPI_TMOD_RO;
-		else
-			chip->tmode = SPI_TMOD_TO;
-
-		cr0 &= ~SPI_TMOD_MASK;
-		cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
-	}
-
+	cr0 = dws->update_cr0(master, spi, transfer);
 	dw_writel(dws, DW_SPI_CTRLR0, cr0);
 
 	/* Check if current transfer is a DMA transaction */
diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
index 445362c23fde..d4d3b0b6f5d5 100644
--- a/drivers/spi/spi-dw.h
+++ b/drivers/spi/spi-dw.h
@@ -114,6 +114,8 @@ struct dw_spi {
 	u16			bus_num;
 	u16			num_cs;		/* supported slave numbers */
 	void (*set_cs)(struct spi_device *spi, bool enable);
+	u32 (*update_cr0)(struct spi_controller *master, struct spi_device *spi,
+			  struct spi_transfer *transfer);
 
 	/* Current message transfer state info */
 	size_t			len;
@@ -252,6 +254,9 @@ extern int dw_spi_add_host(struct device *dev, struct dw_spi *dws);
 extern void dw_spi_remove_host(struct dw_spi *dws);
 extern int dw_spi_suspend_host(struct dw_spi *dws);
 extern int dw_spi_resume_host(struct dw_spi *dws);
+extern u32 dw_spi_update_cr0(struct spi_controller *master,
+			     struct spi_device *spi,
+			     struct spi_transfer *transfer);
 
 /* platform related setup */
 extern int dw_spi_mid_init(struct dw_spi *dws); /* Intel MID platforms */
-- 
2.17.1

[PATCH 3/7] dt-bindings: spi: dw-apb-ssi: Convert bindings to json-schema

[Wan Ahmad Zainie]

Convert the Synopsis DesignWare dw-apb-ssi binding to DT schema format
using json-schema.

Suggested-by: Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 .../bindings/spi/snps,dw-apb-ssi.txt          |  41 -------
 .../bindings/spi/snps,dw-apb-ssi.yaml         | 102 ++++++++++++++++++
 2 files changed, 102 insertions(+), 41 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
 create mode 100644 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml

diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
deleted file mode 100644
index 3ed08ee9feba..000000000000
--- a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
+++ /dev/null
@@ -1,41 +0,0 @@
-Synopsys DesignWare AMBA 2.0 Synchronous Serial Interface.
-
-Required properties:
-- compatible : "snps,dw-apb-ssi" or "mscc,<soc>-spi", where soc is "ocelot" or
-  "jaguar2", or "amazon,alpine-dw-apb-ssi"
-- reg : The register base for the controller. For "mscc,<soc>-spi", a second
-  register set is required (named ICPU_CFG:SPI_MST)
-- interrupts : One interrupt, used by the controller.
-- #address-cells : <1>, as required by generic SPI binding.
-- #size-cells : <0>, also as required by generic SPI binding.
-- clocks : phandles for the clocks, see the description of clock-names below.
-   The phandle for the "ssi_clk" is required. The phandle for the "pclk" clock
-   is optional. If a single clock is specified but no clock-name, it is the
-   "ssi_clk" clock. If both clocks are listed, the "ssi_clk" must be first.
-
-Optional properties:
-- clock-names : Contains the names of the clocks:
-    "ssi_clk", for the core clock used to generate the external SPI clock.
-    "pclk", the interface clock, required for register access. If a clock domain
-     used to enable this clock then it should be named "pclk_clkdomain".
-- cs-gpios : Specifies the gpio pins to be used for chipselects.
-- num-cs : The number of chipselects. If omitted, this will default to 4.
-- reg-io-width : The I/O register width (in bytes) implemented by this
-  device.  Supported values are 2 or 4 (the default).
-
-Child nodes as per the generic SPI binding.
-
-Example:
-
-	spi@fff00000 {
-		compatible = "snps,dw-apb-ssi";
-		reg = <0xfff00000 0x1000>;
-		interrupts = <0 154 4>;
-		#address-cells = <1>;
-		#size-cells = <0>;
-		clocks = <&spi_m_clk>;
-		num-cs = <2>;
-		cs-gpios = <&gpio0 13 0>,
-			   <&gpio0 14 0>;
-	};
-
diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
new file mode 100644
index 000000000000..57a789f5d9f3
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
@@ -0,0 +1,102 @@
+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/spi/snps,dw-apb-ssi.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Synopsys DesignWare AMBA 2.0 Synchronous Serial Interface
+
+maintainers:
+  - Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
+
+allOf:
+  - $ref: spi-controller.yaml#
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - mscc,ocelot-spi
+              - mscc,jaguar2-spi
+      - items:
+          - const: amazon,alpine-dw-apb-ssi
+      - items:
+          - const: snps,dw-apb-ssi
+
+  reg:
+    minItems: 1
+    maxItems: 2
+    oneOf:
+      - items:
+          - description: The register base for the controller.
+      - items:
+          - description: The register base for the controller.
+          - description: For "mscc,<soc>-spi", a second register set is
+                         required (named ICPU_CFG:SPI_MST)
+
+  interrupts:
+    maxItems: 1
+    description: One interrupt, used by the controller.
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  clocks:
+    minItems: 1
+    maxItems: 2
+    description: |
+      phandles for the clocks, see the description of clock-names below.
+      The phandle for the "ssi_clk" is required. The phandle for the "pclk"
+      clock is optional. If a single clock is specified but no clock-name,
+      it is the "ssi_clk" clock. If both clocks are listed, the "ssi_clk"
+      must be first.
+
+  clock-names:
+    items:
+      - const: ssi_clk
+      - const: pclk
+    description: |
+      Contains the names of the clocks.
+      "ssi_clk", for the core clock used to generate the external SPI clock.
+      "pclk", the interface clock, required for register access.
+      If a clock domain used to enable this clock then it should be
+      named "pclk_clkdomain".
+
+  cs-gpios:
+    description: Specifies the gpio pins to be used for chipselects.
+
+  num-cs:
+    default: 4
+    description: The number of chipselects. If omitted, this will default to 4.
+
+  reg-io-width:
+    default: 4
+    description: |
+      The I/O register width (in bytes) implemented by this device.
+      Supported values are 2 or 4 (the default).
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - '#address-cells'
+  - '#size-cells'
+  - clocks
+
+examples:
+  - |
+    spi@fff00000 {
+          compatible = "snps,dw-apb-ssi";
+          reg = <0xfff00000 0x1000>;
+          interrupts = <0 154 4>;
+          #address-cells = <1>;
+          #size-cells = <0>;
+          clocks = <&spi_m_clk>;
+          num-cs = <2>;
+          cs-gpios = <&gpio0 13 0>,
+                     <&gpio0 14 0>;
+    };
-- 
2.17.1

[PATCH 4/7] dt-bindings: spi: dw-apb-ssi: Add compatible string for DesignWare DWC_ssi

[Wan Ahmad Zainie]

This patch adds compatible string "snps,dwc-ssi-1.01a" to the above DT
binding document, to provide support for DesignWare DWC_ssi IP [1].

Current driver supports DW_apb_ssi IP [2].

References:
[1] https://www.synopsys.com/dw/ipdir.php?c=dwc_ssi
[2] https://www.synopsys.com/dw/ipdir.php?c=DW_apb_ssi

Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
index 57a789f5d9f3..36371654ea95 100644
--- a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
+++ b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
@@ -23,6 +23,8 @@ properties:
           - const: amazon,alpine-dw-apb-ssi
       - items:
           - const: snps,dw-apb-ssi
+      - items:
+          - const: snps,dwc-ssi-1.01a
 
   reg:
     minItems: 1
-- 
2.17.1

[PATCH 5/7] spi: dw: Add support for DesignWare DWC_ssi

[Wan Ahmad Zainie]

This patch adds initial support for DesignWare DWC_ssi soft IP. DWC_ssi is
the enhanced version of DW_apb_ssi, which is currently supported by this
driver. Their registers are same, but the bit fields of register CTRLR0
are different.

DWC_ssi has additional features compared to DW_apb_ssi. Major enhancements
in DWC_ssi are hyper bus protocol, boot mode support and advanced XIP
support. DWC_ssi is an AHB slave device, whilst DW_apb_ssi is an APB slave
device.

Register offset
                DW_ssi          DW_apb_ssi
CTRLR0          0x00            0x00
CTRLR1          0x04            0x04
SSIENR          0x08            0x08
MWCR            0x0c            0x0c
SER             0x10            0x10
BAUDR           0x14            0x14
TXFTLR          0x18            0x18
RXFTLR          0x1c            0x1c
TXFLR           0x20            0x20
RXFLR           0x24            0x24
SR              0x28            0x28
IMR             0x2c            0x2c
ISR             0x30            0x30
RISR            0x34            0x34
TXOICR          0x38            0x38
RXOICR          0x3c            0x3c
RXUICR          0x40            0x40
MSTICR          0x44            0x44
ICR             0x48            0x48
DMACR           0x4c            0x4c
DMATDLR         0x50            0x50
DMARDLR         0x54            0x54
IDR             0x58            0x58
SSI_VERSION_ID  0x5c            0x5c
DRx (0 to 35)   0x60+i*0x4      0x60+i*0x4
RX_SAMPLE_DLY   0xf0            0xf0
SPI_CTRLR0      0xf4            0xf4
TXD_DRIVE_EDGE  0xf8            0xf8
XIP_MODE_BITS   0xfc            RSVD

Register configuration - CTRLR0
                        DW_ssi          DW_apb_ssi
  SPI_HYPERBUS_EN       bit[24]         NONE
  SPI_FRF               bit[23:22]      bit[22:21]
  DFS_32                NONE            bit[20:16]
  CFS                   bit[19:16]      bit[15:12]
  SSTE                  bit[14]         bit[24]
  SRL                   bit[13]         bit[11]
  SLV_OE                bit[12]         bit[10]
  TMOD                  bit[11:10]      bit[9:8]
  SCPOL | SPHA          bit[9:8]        bit[7:6]
  FRF                   bit[7:6]        bit[5:4]
  DFS                   bit[4:0]        bit[3:0]

The documents used are
[1] DW_apb_ssi_databook.pdf version 4.01a (2016.10a).
[2] DWC_ssi_databook.pdf version 1.01a.

Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/spi/spi-dw-mmio.c | 10 ++++++++++
 drivers/spi/spi-dw.c      | 41 +++++++++++++++++++++++++++++++++++++++
 drivers/spi/spi-dw.h      | 12 ++++++++++++
 3 files changed, 63 insertions(+)

diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
index a52f75e22109..1df6f3deee2c 100644
--- a/drivers/spi/spi-dw-mmio.c
+++ b/drivers/spi/spi-dw-mmio.c
@@ -146,6 +146,15 @@ static int dw_spi_dw_apb_init(struct platform_device *pdev,
 	return 0;
 }
 
+static int dw_spi_dwc_ssi_init(struct platform_device *pdev,
+			       struct dw_spi_mmio *dwsmmio)
+{
+	/* Register hook to configure CTRLR0 */
+	dwsmmio->dws.update_cr0 = dw_spi_update_cr0_v1_01a;
+
+	return 0;
+}
+
 static int dw_spi_mmio_probe(struct platform_device *pdev)
 {
 	int (*init_func)(struct platform_device *pdev,
@@ -244,6 +253,7 @@ static const struct of_device_id dw_spi_mmio_of_match[] = {
 	{ .compatible = "mscc,jaguar2-spi", .data = dw_spi_mscc_jaguar2_init},
 	{ .compatible = "amazon,alpine-dw-apb-ssi", .data = dw_spi_alpine_init},
 	{ .compatible = "renesas,rzn1-spi", .data = dw_spi_dw_apb_init},
+	{ .compatible = "snps,dwc-ssi-1.01a", .data = dw_spi_dwc_ssi_init},
 	{ /* end of table */}
 };
 MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index b475fd32f39a..109894d20194 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -318,6 +318,47 @@ u32 dw_spi_update_cr0(struct spi_controller *master, struct spi_device *spi,
 }
 EXPORT_SYMBOL_GPL(dw_spi_update_cr0);
 
+/* Configure CTRLR0 for DWC_ssi */
+u32 dw_spi_update_cr0_v1_01a(struct spi_controller *master,
+			     struct spi_device *spi,
+			     struct spi_transfer *transfer)
+{
+	struct dw_spi *dws = spi_controller_get_devdata(master);
+	struct chip_data *chip = spi_get_ctldata(spi);
+	u32 cr0;
+
+	/* CTRLR0[ 4: 0] Data Frame Size */
+	cr0 = (transfer->bits_per_word - 1);
+
+	/* CTRLR0[ 7: 6] Frame Format */
+	cr0 |= chip->type << DWC_SSI_CTRLR0_FRF_OFFSET;
+
+	/*
+	 * SPI mode (SCPOL|SCPH)
+	 * CTRLR0[ 8] Serial Clock Phase
+	 * CTRLR0[ 9] Serial Clock Polarity
+	 */
+	cr0 |= ((spi->mode & SPI_CPOL) ? 1 : 0) << DWC_SSI_CTRLR0_SCPOL_OFFSET;
+	cr0 |= ((spi->mode & SPI_CPHA) ? 1 : 0) << DWC_SSI_CTRLR0_SCPH_OFFSET;
+
+	/* CTRLR0[11:10] Transfer Mode */
+	cr0 |= chip->tmode << DWC_SSI_CTRLR0_TMOD_OFFSET;
+
+	/* CTRLR0[13] Shift Register Loop */
+	cr0 |= ((spi->mode & SPI_LOOP) ? 1 : 0) << DWC_SSI_CTRLR0_SRL_OFFSET;
+
+	/* Adjust Transfer Mode if necessary */
+	if (chip->cs_control) {
+		chip->tmode = dw_spi_update_tmode(dws);
+
+		cr0 &= ~DWC_SSI_CTRLR0_TMOD_MASK;
+		cr0 |= chip->tmode << DWC_SSI_CTRLR0_TMOD_OFFSET;
+	}
+
+	return cr0;
+}
+EXPORT_SYMBOL_GPL(dw_spi_update_cr0_v1_01a);
+
 static int dw_spi_transfer_one(struct spi_controller *master,
 		struct spi_device *spi, struct spi_transfer *transfer)
 {
diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
index d4d3b0b6f5d5..9c237d56f213 100644
--- a/drivers/spi/spi-dw.h
+++ b/drivers/spi/spi-dw.h
@@ -57,6 +57,15 @@
 #define SPI_SRL_OFFSET			11
 #define SPI_CFS_OFFSET			12
 
+/* Bit fields in CTRLR0 based on DWC_ssi_databook.pdf v1.01a */
+#define DWC_SSI_CTRLR0_SRL_OFFSET	13
+#define DWC_SSI_CTRLR0_TMOD_OFFSET	10
+#define DWC_SSI_CTRLR0_TMOD_MASK	GENMASK(11, 10)
+#define DWC_SSI_CTRLR0_SCPOL_OFFSET	9
+#define DWC_SSI_CTRLR0_SCPH_OFFSET	8
+#define DWC_SSI_CTRLR0_FRF_OFFSET	6
+#define DWC_SSI_CTRLR0_DFS_OFFSET	0
+
 /* Bit fields in SR, 7 bits */
 #define SR_MASK				0x7f		/* cover 7 bits */
 #define SR_BUSY				(1 << 0)
@@ -257,6 +266,9 @@ extern int dw_spi_resume_host(struct dw_spi *dws);
 extern u32 dw_spi_update_cr0(struct spi_controller *master,
 			     struct spi_device *spi,
 			     struct spi_transfer *transfer);
+extern u32 dw_spi_update_cr0_v1_01a(struct spi_controller *master,
+				    struct spi_device *spi,
+				    struct spi_transfer *transfer);
 
 /* platform related setup */
 extern int dw_spi_mid_init(struct dw_spi *dws); /* Intel MID platforms */
-- 
2.17.1

[PATCH 6/7] dt-bindings: spi: dw-apb-ssi: Add Intel Keem Bay support

[Wan Ahmad Zainie]

Document Intel Keem Bay SPI controller DT bindings.

Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
index 36371654ea95..8d3b6ee36266 100644
--- a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
+++ b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
@@ -25,6 +25,8 @@ properties:
           - const: snps,dw-apb-ssi
       - items:
           - const: snps,dwc-ssi-1.01a
+      - items:
+          - const: intel,keembay-ssi
 
   reg:
     minItems: 1
-- 
2.17.1

[PATCH 7/7] spi: dw: Add support for Intel Keem Bay SPI

[Wan Ahmad Zainie]

Add support for Intel Keem Bay SPI controller, which uses DesignWare
DWC_ssi core. Bit 31 of CTRLR0 register is added for Keem Bay, to
configure the device as a master or as a slave serial peripheral.

Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/spi/spi-dw-mmio.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
index 1df6f3deee2c..abd3bb5e52db 100644
--- a/drivers/spi/spi-dw-mmio.c
+++ b/drivers/spi/spi-dw-mmio.c
@@ -44,6 +44,13 @@ struct dw_spi_mmio {
 #define MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE	BIT(13)
 #define MSCC_SPI_MST_SW_MODE_SW_SPI_CS(x)	(x << 5)
 
+/*
+ * For Keem Bay, CTRLR0[31] is used to select controller mode.
+ * 0: SSI is slave
+ * 1: SSI is master
+ */
+#define KEEMBAY_CTRLR0_SSIC_IS_MST		BIT(31)
+
 struct dw_spi_mscc {
 	struct regmap       *syscon;
 	void __iomem        *spi_mst;
@@ -155,6 +162,24 @@ static int dw_spi_dwc_ssi_init(struct platform_device *pdev,
 	return 0;
 }
 
+static u32 dw_spi_update_cr0_keembay(struct spi_controller *master,
+				     struct spi_device *spi,
+				     struct spi_transfer *transfer)
+{
+	u32 cr0 = dw_spi_update_cr0_v1_01a(master, spi, transfer);
+
+	return cr0 | KEEMBAY_CTRLR0_SSIC_IS_MST;
+}
+
+static int dw_spi_keembay_init(struct platform_device *pdev,
+			       struct dw_spi_mmio *dwsmmio)
+{
+	/* Register hook to configure CTRLR0 */
+	dwsmmio->dws.update_cr0 = dw_spi_update_cr0_keembay;
+
+	return 0;
+}
+
 static int dw_spi_mmio_probe(struct platform_device *pdev)
 {
 	int (*init_func)(struct platform_device *pdev,
@@ -254,6 +279,7 @@ static const struct of_device_id dw_spi_mmio_of_match[] = {
 	{ .compatible = "amazon,alpine-dw-apb-ssi", .data = dw_spi_alpine_init},
 	{ .compatible = "renesas,rzn1-spi", .data = dw_spi_dw_apb_init},
 	{ .compatible = "snps,dwc-ssi-1.01a", .data = dw_spi_dwc_ssi_init},
+	{ .compatible = "intel,keembay-ssi", .data = dw_spi_keembay_init},
 	{ /* end of table */}
 };
 MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
-- 
2.17.1

Re: [PATCH 3/7] dt-bindings: spi: dw-apb-ssi: Convert bindings to json-schema

[Rob Herring]

On Thu, Mar 12, 2020 at 07:31:25PM +0800, Wan Ahmad Zainie wrote:
> Convert the Synopsis DesignWare dw-apb-ssi binding to DT schema format
> using json-schema.
> 
> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
> ---
>  .../bindings/spi/snps,dw-apb-ssi.txt          |  41 -------
>  .../bindings/spi/snps,dw-apb-ssi.yaml         | 102 ++++++++++++++++++
>  2 files changed, 102 insertions(+), 41 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
>  create mode 100644 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
> deleted file mode 100644
> index 3ed08ee9feba..000000000000
> --- a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
> +++ /dev/null
> @@ -1,41 +0,0 @@
> -Synopsys DesignWare AMBA 2.0 Synchronous Serial Interface.
> -
> -Required properties:
> -- compatible : "snps,dw-apb-ssi" or "mscc,<soc>-spi", where soc is "ocelot" or
> -  "jaguar2", or "amazon,alpine-dw-apb-ssi"
> -- reg : The register base for the controller. For "mscc,<soc>-spi", a second
> -  register set is required (named ICPU_CFG:SPI_MST)
> -- interrupts : One interrupt, used by the controller.
> -- #address-cells : <1>, as required by generic SPI binding.
> -- #size-cells : <0>, also as required by generic SPI binding.
> -- clocks : phandles for the clocks, see the description of clock-names below.
> -   The phandle for the "ssi_clk" is required. The phandle for the "pclk" clock
> -   is optional. If a single clock is specified but no clock-name, it is the
> -   "ssi_clk" clock. If both clocks are listed, the "ssi_clk" must be first.
> -
> -Optional properties:
> -- clock-names : Contains the names of the clocks:
> -    "ssi_clk", for the core clock used to generate the external SPI clock.
> -    "pclk", the interface clock, required for register access. If a clock domain
> -     used to enable this clock then it should be named "pclk_clkdomain".
> -- cs-gpios : Specifies the gpio pins to be used for chipselects.
> -- num-cs : The number of chipselects. If omitted, this will default to 4.
> -- reg-io-width : The I/O register width (in bytes) implemented by this
> -  device.  Supported values are 2 or 4 (the default).
> -
> -Child nodes as per the generic SPI binding.
> -
> -Example:
> -
> -	spi@fff00000 {
> -		compatible = "snps,dw-apb-ssi";
> -		reg = <0xfff00000 0x1000>;
> -		interrupts = <0 154 4>;
> -		#address-cells = <1>;
> -		#size-cells = <0>;
> -		clocks = <&spi_m_clk>;
> -		num-cs = <2>;
> -		cs-gpios = <&gpio0 13 0>,
> -			   <&gpio0 14 0>;
> -	};
> -
> diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> new file mode 100644
> index 000000000000..57a789f5d9f3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> @@ -0,0 +1,102 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/spi/snps,dw-apb-ssi.yaml#"
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> +
> +title: Synopsys DesignWare AMBA 2.0 Synchronous Serial Interface
> +
> +maintainers:
> +  - Mark Brown <broonie@kernel.org>

Should be owner for this h/w, not who takes patches.

> +
> +allOf:
> +  - $ref: spi-controller.yaml#
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - items:
> +          - enum:
> +              - mscc,ocelot-spi
> +              - mscc,jaguar2-spi
> +      - items:
> +          - const: amazon,alpine-dw-apb-ssi
> +      - items:
> +          - const: snps,dw-apb-ssi

This can all be a single 'enum'. You only need 'oneOf' if there are a 
different number of compatible entries.

> +
> +  reg:
> +    minItems: 1
> +    maxItems: 2
> +    oneOf:
> +      - items:
> +          - description: The register base for the controller.
> +      - items:
> +          - description: The register base for the controller.
> +          - description: For "mscc,<soc>-spi", a second register set is
> +                         required (named ICPU_CFG:SPI_MST)

No need for the oneOf. The 2nd case is a superset of the 1st.

> +
> +  interrupts:
> +    maxItems: 1
> +    description: One interrupt, used by the controller.

Can drop description. Not specific to this h/w.

> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0

Drop these 2. Covered by spi-controller.yaml.

> +
> +  clocks:
> +    minItems: 1
> +    maxItems: 2
> +    description: |
> +      phandles for the clocks, see the description of clock-names below.
> +      The phandle for the "ssi_clk" is required. The phandle for the "pclk"
> +      clock is optional. If a single clock is specified but no clock-name,
> +      it is the "ssi_clk" clock. If both clocks are listed, the "ssi_clk"
> +      must be first.

Rework like:

items:
  - description: ...
  - description: ...

> +
> +  clock-names:
> +    items:
> +      - const: ssi_clk
> +      - const: pclk
> +    description: |
> +      Contains the names of the clocks.
> +      "ssi_clk", for the core clock used to generate the external SPI clock.
> +      "pclk", the interface clock, required for register access.

No need to repeat what's in clocks.

> +      If a clock domain used to enable this clock then it should be
> +      named "pclk_clkdomain".

Should be a constraint:

enum: [pclk, pclk_clkdomain]

But really, it probably should be dropped. I don't understand what the 
sentence is supposed to mean.

> +
> +  cs-gpios:
> +    description: Specifies the gpio pins to be used for chipselects.

Can drop, covered by spi-controller.yaml.

> +
> +  num-cs:
> +    default: 4
> +    description: The number of chipselects. If omitted, this will default to 4.

Constraints?

> +
> +  reg-io-width:
> +    default: 4
> +    description: |
> +      The I/O register width (in bytes) implemented by this device.
> +      Supported values are 2 or 4 (the default).

2 or 4?, sounds like constraints.

> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - '#address-cells'
> +  - '#size-cells'
> +  - clocks
> +
> +examples:
> +  - |
> +    spi@fff00000 {
> +          compatible = "snps,dw-apb-ssi";
> +          reg = <0xfff00000 0x1000>;
> +          interrupts = <0 154 4>;
> +          #address-cells = <1>;
> +          #size-cells = <0>;
> +          clocks = <&spi_m_clk>;
> +          num-cs = <2>;
> +          cs-gpios = <&gpio0 13 0>,
> +                     <&gpio0 14 0>;
> +    };
> -- 
> 2.17.1
> 

RE: [PATCH 3/7] dt-bindings: spi: dw-apb-ssi: Convert bindings to json-schema

[Wan Mohamad, Wan Ahmad Zainie]

> -----Original Message-----
> From: Rob Herring <robh@kernel.org>
> Sent: Tuesday, March 31, 2020 12:55 AM
> To: Wan Mohamad, Wan Ahmad Zainie
> <wan.ahmad.zainie.wan.mohamad@intel.com>
> Cc: broonie@kernel.org; mark.rutland@arm.com; linux-spi@vger.kernel.org;
> devicetree@vger.kernel.org
> Subject: Re: [PATCH 3/7] dt-bindings: spi: dw-apb-ssi: Convert bindings to
> json-schema
> 
> On Thu, Mar 12, 2020 at 07:31:25PM +0800, Wan Ahmad Zainie wrote:
> > Convert the Synopsis DesignWare dw-apb-ssi binding to DT schema format
> > using json-schema.
> >
> > Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > Signed-off-by: Wan Ahmad Zainie
> > <wan.ahmad.zainie.wan.mohamad@intel.com>
> > ---
> >  .../bindings/spi/snps,dw-apb-ssi.txt          |  41 -------
> >  .../bindings/spi/snps,dw-apb-ssi.yaml         | 102 ++++++++++++++++++
> >  2 files changed, 102 insertions(+), 41 deletions(-)  delete mode
> > 100644 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
> >  create mode 100644
> > Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
> > b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
> > deleted file mode 100644
> > index 3ed08ee9feba..000000000000
> > --- a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
> > +++ /dev/null
> > @@ -1,41 +0,0 @@
> > -Synopsys DesignWare AMBA 2.0 Synchronous Serial Interface.
> > -
> > -Required properties:
> > -- compatible : "snps,dw-apb-ssi" or "mscc,<soc>-spi", where soc is
> > "ocelot" or
> > -  "jaguar2", or "amazon,alpine-dw-apb-ssi"
> > -- reg : The register base for the controller. For "mscc,<soc>-spi", a
> > second
> > -  register set is required (named ICPU_CFG:SPI_MST)
> > -- interrupts : One interrupt, used by the controller.
> > -- #address-cells : <1>, as required by generic SPI binding.
> > -- #size-cells : <0>, also as required by generic SPI binding.
> > -- clocks : phandles for the clocks, see the description of clock-names
> below.
> > -   The phandle for the "ssi_clk" is required. The phandle for the "pclk" clock
> > -   is optional. If a single clock is specified but no clock-name, it is the
> > -   "ssi_clk" clock. If both clocks are listed, the "ssi_clk" must be first.
> > -
> > -Optional properties:
> > -- clock-names : Contains the names of the clocks:
> > -    "ssi_clk", for the core clock used to generate the external SPI clock.
> > -    "pclk", the interface clock, required for register access. If a clock domain
> > -     used to enable this clock then it should be named "pclk_clkdomain".
> > -- cs-gpios : Specifies the gpio pins to be used for chipselects.
> > -- num-cs : The number of chipselects. If omitted, this will default to 4.
> > -- reg-io-width : The I/O register width (in bytes) implemented by
> > this
> > -  device.  Supported values are 2 or 4 (the default).
> > -
> > -Child nodes as per the generic SPI binding.
> > -
> > -Example:
> > -
> > -	spi@fff00000 {
> > -		compatible = "snps,dw-apb-ssi";
> > -		reg = <0xfff00000 0x1000>;
> > -		interrupts = <0 154 4>;
> > -		#address-cells = <1>;
> > -		#size-cells = <0>;
> > -		clocks = <&spi_m_clk>;
> > -		num-cs = <2>;
> > -		cs-gpios = <&gpio0 13 0>,
> > -			   <&gpio0 14 0>;
> > -	};
> > -
> > diff --git
> > a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> > b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> > new file mode 100644
> > index 000000000000..57a789f5d9f3
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> > @@ -0,0 +1,102 @@
> > +# SPDX-License-Identifier: GPL-2.0-only %YAML 1.2
> > +---
> > +$id: "http://devicetree.org/schemas/spi/snps,dw-apb-ssi.yaml#"
> > +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> > +
> > +title: Synopsys DesignWare AMBA 2.0 Synchronous Serial Interface
> > +
> > +maintainers:
> > +  - Mark Brown <broonie@kernel.org>
> 
> Should be owner for this h/w, not who takes patches.

I will ask internally, who is the current owner.

> 
> > +
> > +allOf:
> > +  - $ref: spi-controller.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
> > +      - items:
> > +          - enum:
> > +              - mscc,ocelot-spi
> > +              - mscc,jaguar2-spi
> > +      - items:
> > +          - const: amazon,alpine-dw-apb-ssi
> > +      - items:
> > +          - const: snps,dw-apb-ssi
> 
> This can all be a single 'enum'. You only need 'oneOf' if there are a different
> number of compatible entries.
> 
> > +
> > +  reg:
> > +    minItems: 1
> > +    maxItems: 2
> > +    oneOf:
> > +      - items:
> > +          - description: The register base for the controller.
> > +      - items:
> > +          - description: The register base for the controller.
> > +          - description: For "mscc,<soc>-spi", a second register set is
> > +                         required (named ICPU_CFG:SPI_MST)
> 
> No need for the oneOf. The 2nd case is a superset of the 1st.
> 
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +    description: One interrupt, used by the controller.
> 
> Can drop description. Not specific to this h/w.
> 
> > +
> > +  '#address-cells':
> > +    const: 1
> > +
> > +  '#size-cells':
> > +    const: 0
> 
> Drop these 2. Covered by spi-controller.yaml.
> 
> > +
> > +  clocks:
> > +    minItems: 1
> > +    maxItems: 2
> > +    description: |
> > +      phandles for the clocks, see the description of clock-names below.
> > +      The phandle for the "ssi_clk" is required. The phandle for the "pclk"
> > +      clock is optional. If a single clock is specified but no clock-name,
> > +      it is the "ssi_clk" clock. If both clocks are listed, the "ssi_clk"
> > +      must be first.
> 
> Rework like:
> 
> items:
>   - description: ...
>   - description: ...
> 
> > +
> > +  clock-names:
> > +    items:
> > +      - const: ssi_clk
> > +      - const: pclk
> > +    description: |
> > +      Contains the names of the clocks.
> > +      "ssi_clk", for the core clock used to generate the external SPI clock.
> > +      "pclk", the interface clock, required for register access.
> 
> No need to repeat what's in clocks.
> 
> > +      If a clock domain used to enable this clock then it should be
> > +      named "pclk_clkdomain".
> 
> Should be a constraint:
> 
> enum: [pclk, pclk_clkdomain]
> 
> But really, it probably should be dropped. I don't understand what the
> sentence is supposed to mean.

I checked against source code, and no code in drivers/spi/ is using pclk_clkdomain,
so it is safe to remove. 

> 
> > +
> > +  cs-gpios:
> > +    description: Specifies the gpio pins to be used for chipselects.
> 
> Can drop, covered by spi-controller.yaml.
> 
> > +
> > +  num-cs:
> > +    default: 4
> > +    description: The number of chipselects. If omitted, this will default to 4.
> 
> Constraints?

I believe this is not a constraint.
Native chip select for this hardware is usually 4. We can have additional chip select
using GPIOs.

> 
> > +
> > +  reg-io-width:
> > +    default: 4
> > +    description: |
> > +      The I/O register width (in bytes) implemented by this device.
> > +      Supported values are 2 or 4 (the default).
> 
> 2 or 4?, sounds like constraints.

Yes, it is either 2 or 4 only.

I will fix this and all your comments that I haven't reply above.
Thanks for the review and comment.

> 
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +  - '#address-cells'
> > +  - '#size-cells'
> > +  - clocks
> > +
> > +examples:
> > +  - |
> > +    spi@fff00000 {
> > +          compatible = "snps,dw-apb-ssi";
> > +          reg = <0xfff00000 0x1000>;
> > +          interrupts = <0 154 4>;
> > +          #address-cells = <1>;
> > +          #size-cells = <0>;
> > +          clocks = <&spi_m_clk>;
> > +          num-cs = <2>;
> > +          cs-gpios = <&gpio0 13 0>,
> > +                     <&gpio0 14 0>;
> > +    };
> > --
> > 2.17.1
> >