Merge series "spi: Adding support for Microchip Sparx5 SoC" from Lars Povlsen...

Merge series "spi: Adding support for Microchip Sparx5 SoC" from Lars Povlsen <lars.povlsen@microchip.com>:

The series add support for the Sparx5 SoC SPI controller in the
spi-dw-mmio.c spi driver.

v5 changes:
- rx-sample-delay-ns documentation changes from Rob Herring:
 - Drop superfluous type $ref
 - Add default value = 0

v4 changes:
- Changed snps,rx-sample-delay-ns to snps,rx-sample-delay-ns
  suggested by Rob Herring (rockchip also has this property).
- Added support for controller-level rx-sample-delay-ns value as
  well as per SPI slave value (rockchip has controller-level property).
- Dropped internal mux in favor of suggested spi-mux to
  control bus inteface selection.

v3 changes:
- Added mux support for controlling SPI bus interface. This is new mux
  driver, bindings and added to sparx5 base DT.
- Removed "microchip,spi-interface2" property in favour of
  "mux-controls" property in SPI controller (sparx5 only).
- Changed dw_spi_sparx5_set_cs() to use the mux control instead of
  directly acessing "mux" register. Associated code/defines moved to mux
  driver.
- Changed dw_spi_sparx5_set_cs() to match other similar functions in
  signature and avoid explicit CS toggling.
- Spun off duplicated NAND device DT chunks into separate DT file.

v2 changes:
- Moved all RX sample delay into spi-dw-core.c, using
  the "snps,rx-sample-delay-ns" device property.
- Integrated Sparx5 support directly in spi-dw-mmio.c
- Changed SPI2 configuration to per-slave "microchip,spi-interface2"
  property.
- Added bindings to existing snps,dw-apb-ssi.yaml file
- Dropped patches for polled mode and SPI memory operations.

Lars Povlsen (6):
  spi: dw: Add support for RX sample delay register
  spi: dw: Add Microchip Sparx5 support
  arm64: dts: sparx5: Add SPI controller and associated mmio-mux
  dt-bindings: snps,dw-apb-ssi: Add sparx5 support, plus
    rx-sample-delay-ns property
  arm64: dts: sparx5: Add spi-nor support
  arm64: dts: sparx5: Add spi-nand devices

 .../bindings/spi/snps,dw-apb-ssi.yaml         | 21 ++++++
 arch/arm64/boot/dts/microchip/sparx5.dtsi     | 47 ++++++++++++-
 .../arm64/boot/dts/microchip/sparx5_nand.dtsi | 31 ++++++++
 .../boot/dts/microchip/sparx5_pcb125.dts      | 30 ++++++++
 .../boot/dts/microchip/sparx5_pcb134.dts      |  1 +
 .../dts/microchip/sparx5_pcb134_board.dtsi    | 16 +++++
 .../boot/dts/microchip/sparx5_pcb135.dts      |  1 +
 .../dts/microchip/sparx5_pcb135_board.dtsi    | 16 +++++
 drivers/spi/spi-dw-core.c                     | 26 +++++++
 drivers/spi/spi-dw-mmio.c                     | 70 ++++++++++++++++++-
 drivers/spi/spi-dw.h                          |  3 +
 11 files changed, 260 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm64/boot/dts/microchip/sparx5_nand.dtsi

--
2.27.0

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Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml

@@ -36,6 +36,8 @@ properties:
               - mscc,ocelot-spi
               - mscc,jaguar2-spi
           - const: snps,dw-apb-ssi
+      - description: Microchip Sparx5 SoC SPI Controller
+        const: microchip,sparx5-spi
       - description: Amazon Alpine SPI Controller
         const: amazon,alpine-dw-apb-ssi
       - description: Renesas RZ/N1 SPI Controller
@@ -93,6 +95,12 @@ properties:
       - const: tx
       - const: rx
 
+  rx-sample-delay-ns:
+    default: 0
+    description: Default value of the rx-sample-delay-ns property.
+      This value will be used if the property is not explicitly defined
+      for a SPI slave device. See below.
+
 patternProperties:
   "^.*@[0-9a-f]+$":
     type: object
@@ -107,6 +115,13 @@ patternProperties:
       spi-tx-bus-width:
         const: 1
 
+      rx-sample-delay-ns:
+        description: SPI Rx sample delay offset, unit is nanoseconds.
+          The delay from the default sample time before the actual
+          sample of the rxd input signal occurs. The "rx_sample_delay"
+          is an optional feature of the designware controller, and the
+          upper limit is also subject to controller configuration.
+
 unevaluatedProperties: false
 
 required:
@@ -129,5 +144,11 @@ examples:
       num-cs = <2>;
       cs-gpios = <&gpio0 13 0>,
                  <&gpio0 14 0>;
+      rx-sample-delay-ns = <3>;
+      spi-flash@1 {
+        compatible = "spi-nand";
+        reg = <1>;
+        rx-sample-delay-ns = <7>;
+      };
     };
 ...

drivers/spi/spi-dw-core.c

@@ -12,6 +12,7 @@
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/spi/spi.h>
+#include <linux/of.h>
 
 #include "spi-dw.h"
 
@@ -26,6 +27,8 @@ struct chip_data {
 
 	u16 clk_div;		/* baud rate divider */
 	u32 speed_hz;		/* baud rate */
+
+	u32 rx_sample_dly;	/* RX sample delay */
 };
 
 #ifdef CONFIG_DEBUG_FS
@@ -52,6 +55,7 @@ static const struct debugfs_reg32 dw_spi_dbgfs_regs[] = {
 	DW_SPI_DBGFS_REG("DMACR", DW_SPI_DMACR),
 	DW_SPI_DBGFS_REG("DMATDLR", DW_SPI_DMATDLR),
 	DW_SPI_DBGFS_REG("DMARDLR", DW_SPI_DMARDLR),
+	DW_SPI_DBGFS_REG("RX_SAMPLE_DLY", DW_SPI_RX_SAMPLE_DLY),
 };
 
 static int dw_spi_debugfs_init(struct dw_spi *dws)
@@ -328,6 +332,12 @@ static int dw_spi_transfer_one(struct spi_controller *master,
 	if (master->can_dma && master->can_dma(master, spi, transfer))
 		dws->dma_mapped = master->cur_msg_mapped;
 
+	/* Update RX sample delay if required */
+	if (dws->cur_rx_sample_dly != chip->rx_sample_dly) {
+		dw_writel(dws, DW_SPI_RX_SAMPLE_DLY, chip->rx_sample_dly);
+		dws->cur_rx_sample_dly = chip->rx_sample_dly;
+	}
+
 	/* For poll mode just disable all interrupts */
 	spi_mask_intr(dws, 0xff);
 
@@ -380,10 +390,22 @@ static int dw_spi_setup(struct spi_device *spi)
 	/* Only alloc on first setup */
 	chip = spi_get_ctldata(spi);
 	if (!chip) {
+		struct dw_spi *dws = spi_controller_get_devdata(spi->controller);
+		u32 rx_sample_dly_ns;
+
 		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
 		if (!chip)
 			return -ENOMEM;
 		spi_set_ctldata(spi, chip);
+		/* Get specific / default rx-sample-delay */
+		if (device_property_read_u32(&spi->dev,
+					     "rx-sample-delay-ns",
+					     &rx_sample_dly_ns) != 0)
+			/* Use default controller value */
+			rx_sample_dly_ns = dws->def_rx_sample_dly_ns;
+		chip->rx_sample_dly = DIV_ROUND_CLOSEST(rx_sample_dly_ns,
+							NSEC_PER_SEC /
+							dws->max_freq);
 	}
 
 	chip->tmode = SPI_TMOD_TR;
@@ -472,6 +494,10 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
 	if (dws->set_cs)
 		master->set_cs = dws->set_cs;
 
+	/* Get default rx sample delay */
+	device_property_read_u32(dev, "rx-sample-delay-ns",
+				 &dws->def_rx_sample_dly_ns);
+
 	/* Basic HW init */
 	spi_hw_init(dev, dws);
 

drivers/spi/spi-dw-mmio.c

@@ -45,6 +45,9 @@ 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)
 
+#define SPARX5_FORCE_ENA			0xa4
+#define SPARX5_FORCE_VAL			0xa8
+
 /*
  * For Keem Bay, CTRLR0[31] is used to select controller mode.
  * 0: SSI is slave
@@ -54,7 +57,7 @@ struct dw_spi_mmio {
 
 struct dw_spi_mscc {
 	struct regmap       *syscon;
-	void __iomem        *spi_mst;
+	void __iomem        *spi_mst; /* Not sparx5 */
 };
 
 /*
@@ -134,6 +137,70 @@ static int dw_spi_mscc_jaguar2_init(struct platform_device *pdev,
 				JAGUAR2_IF_SI_OWNER_OFFSET);
 }
 
+/*
+ * The Designware SPI controller (referred to as master in the
+ * documentation) automatically deasserts chip select when the tx fifo
+ * is empty. The chip selects then needs to be driven by a CS override
+ * register. enable is an active low signal.
+ */
+static void dw_spi_sparx5_set_cs(struct spi_device *spi, bool enable)
+{
+	struct dw_spi *dws = spi_master_get_devdata(spi->master);
+	struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
+	struct dw_spi_mscc *dwsmscc = dwsmmio->priv;
+	u8 cs = spi->chip_select;
+
+	if (!enable) {
+		/* CS override drive enable */
+		regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 1);
+		/* Now set CSx enabled */
+		regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~BIT(cs));
+		/* Allow settle */
+		usleep_range(1, 5);
+	} else {
+		/* CS value */
+		regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~0);
+		/* Allow settle */
+		usleep_range(1, 5);
+		/* CS override drive disable */
+		regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 0);
+	}
+
+	dw_spi_set_cs(spi, enable);
+}
+
+static int dw_spi_mscc_sparx5_init(struct platform_device *pdev,
+				   struct dw_spi_mmio *dwsmmio)
+{
+	const char *syscon_name = "microchip,sparx5-cpu-syscon";
+	struct device *dev = &pdev->dev;
+	struct dw_spi_mscc *dwsmscc;
+
+	if (!IS_ENABLED(CONFIG_SPI_MUX)) {
+		dev_err(dev, "This driver needs CONFIG_SPI_MUX\n");
+		return -EOPNOTSUPP;
+	}
+
+	dwsmscc = devm_kzalloc(dev, sizeof(*dwsmscc), GFP_KERNEL);
+	if (!dwsmscc)
+		return -ENOMEM;
+
+	dwsmscc->syscon =
+		syscon_regmap_lookup_by_compatible(syscon_name);
+	if (IS_ERR(dwsmscc->syscon)) {
+		dev_err(dev, "No syscon map %s\n", syscon_name);
+		return PTR_ERR(dwsmscc->syscon);
+	}
+
+	dwsmmio->dws.set_cs = dw_spi_sparx5_set_cs;
+	dwsmmio->priv = dwsmscc;
+
+	/* Register hook to configure CTRLR0 */
+	dwsmmio->dws.update_cr0 = dw_spi_update_cr0;
+
+	return 0;
+}
+
 static int dw_spi_alpine_init(struct platform_device *pdev,
 			      struct dw_spi_mmio *dwsmmio)
 {
@@ -297,6 +364,7 @@ static const struct of_device_id dw_spi_mmio_of_match[] = {
 	{ .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},
+	{ .compatible = "microchip,sparx5-spi", dw_spi_mscc_sparx5_init},
 	{ /* end of table */}
 };
 MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);

drivers/spi/spi-dw.h

@@ -34,6 +34,7 @@
 #define DW_SPI_IDR			0x58
 #define DW_SPI_VERSION			0x5c
 #define DW_SPI_DR			0x60
+#define DW_SPI_RX_SAMPLE_DLY		0xf0
 #define DW_SPI_CS_OVERRIDE		0xf4
 
 /* Bit fields in CTRLR0 */
@@ -140,6 +141,8 @@ struct dw_spi {
 	u8			n_bytes;	/* current is a 1/2 bytes op */
 	irqreturn_t		(*transfer_handler)(struct dw_spi *dws);
 	u32			current_freq;	/* frequency in hz */
+	u32			cur_rx_sample_dly;
+	u32			def_rx_sample_dly_ns;
 
 	/* DMA info */
 	struct dma_chan		*txchan;