[PATCH v4 0/2] add support for Cadence's XSPI controller

[PATCH v4 0/2] add support for Cadence's XSPI controller

[Parshuram Thombare]

This patch series adds support for Cadence's XSPI controller.
It supports 3 work modes.
1. ACMD (auto command) work mode
    ACMD name is because it uses auto command engine in the controller.
    It further has 2 modes PIO and CDMA (command DMA).
    The CDMA work mode is dedicated for high-performance application
    where very low software overhead is required. In this mode the
    Command Engine is programmed by the series of linked descriptors
    stored in system memory. These descriptors provide commands to execute
    and store status information for finished commands.
    The PIO mode work mode is dedicated for single operation where
    constructing a linked list of descriptors would require too
    much effort.
2. STIG (Software Triggered Instruction Generator) work mode
    In STIG mode, controller sends low-level instructions to memory.
    Each instruction is 128-bit width. There is special instruction
    DataSequence which carries information about data phase.
    Driver uses Slave DMA interface to transfer data as only this
    interface can be used in STIG work mode.
3. Direct work mode
    This work mode allows sending data without invoking any command through
    the slave interface.
Currently only STIG work mode is enabled, remaining work modes will
be added later.

Changes since v3:
1. Removed ACMD PIO mode.
2. Return IRQ_HANDLED only for handled interrupts.
3. DT binding changes.

Changes since v2:
1. Removed extra lock around exec_op.
2. Removed PHY parameters setting from the driver, those will be
   handled by bootstrap pins available in the controller.

Changes since v1:
1. Use ACMD PIO work mode for NOR read, program and erase operations,
   for everything else use STIG(Software Triggered Instruction
   Generator) work mode.
2. Changes suggested by Lukas.

Parshuram Thombare (2):
  spi: cadence: add dt-bindings documentation for Cadence XSPI
    controller
  spi: cadence: add support for Cadence XSPI controller

 .../devicetree/bindings/spi/cdns,xspi.yaml         |  77 +++
 drivers/spi/Kconfig                                |  12 +
 drivers/spi/Makefile                               |   1 +
 drivers/spi/spi-cadence-xspi.c                     | 627 +++++++++++++++++++++
 4 files changed, 717 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/cdns,xspi.yaml
 create mode 100644 drivers/spi/spi-cadence-xspi.c

-- 
2.7.4

[PATCH v4 1/2] spi: cadence: add dt-bindings documentation for Cadence XSPI controller

[Parshuram Thombare]

Add DT binding for Cadence's XSPI controller driver.

Signed-off-by: Konrad Kociolek <konrad@cadence.com>
Signed-off-by: Jayshri Pawar <jpawar@cadence.com>
Signed-off-by: Parshuram Thombare <pthombar@cadence.com>
---
 .../devicetree/bindings/spi/cdns,xspi.yaml         | 77 ++++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/cdns,xspi.yaml

diff --git a/Documentation/devicetree/bindings/spi/cdns,xspi.yaml b/Documentation/devicetree/bindings/spi/cdns,xspi.yaml
new file mode 100644
index 0000000..5ebede1
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/cdns,xspi.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2020-21 Cadence
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/spi/cdns,xspi.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Cadence XSPI Controller
+
+maintainers:
+  - Parshuram Thombare <pthombar@cadence.com>
+
+description: |
+  The XSPI controller allows SPI protocol communication in
+  single, dual, quad or octal wire transmission modes for
+  read/write access to slaves such as SPI-NOR flash.
+
+allOf:
+  - $ref: "spi-controller.yaml#"
+
+properties:
+  compatible:
+    const: cdns,xspi-nor
+
+  reg:
+    items:
+      - description: address and length of the controller register set
+      - description: address and length of the Slave DMA data port
+      - description: address and length of the auxiliary registers
+
+  reg-names:
+    items:
+      - const: xspi-iobase
+      - const: xspi-sdmabase
+      - const: xspi-auxbase
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    bus {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        xspi: spi@a0010000 {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            compatible = "cdns,xspi-nor";
+            reg = <0x0 0xa0010000 0x0 0x10000>,
+                  <0x0 0xb0000000 0x0 0x10000>,
+                  <0x0 0xa0020000 0x0 0x10000>;
+            reg-names = "xspi-iobase", "xspi-sdmabase", "xspi-auxbase";
+            interrupts = <0 90 IRQ_TYPE_LEVEL_HIGH>;
+            interrupt-parent = <&gic>;
+
+            flash@0 {
+                compatible = "jedec,spi-nor";
+                spi-max-frequency = <75000000>;
+                reg = <0>;
+            };
+
+            flash@1 {
+                compatible = "jedec,spi-nor";
+                spi-max-frequency = <75000000>;
+                reg = <1>;
+            };
+        };
+    };
-- 
2.7.4

[PATCH v4 2/2] spi: cadence: add support for Cadence XSPI controller

[Parshuram Thombare]

This patch adds driver for Cadence's XSPI controller.
It supports 3 work modes.
1. ACMD (auto command) work mode
    ACMD name is because it uses auto command engine in the controller.
    It further has 2 modes PIO and CDMA (command DMA).
    The CDMA work mode is dedicated for high-performance application
    where very low software overhead is required. In this mode the
    Command Engine is programmed by the series of linked descriptors
    stored in system memory. These descriptors provide commands to execute
    and store status information for finished commands.
    The PIO mode work mode is dedicated for single operation where
    constructing a linked list of descriptors would require too
    much effort.
2. STIG (Software Triggered Instruction Generator) work mode
    In STIG mode, controller sends low-level instructions to memory.
    Each instruction is 128-bit width. There is special instruction
    DataSequence which carries information about data phase.
    Driver uses Slave DMA interface to transfer data as only this
    interface can be used in STIG work mode.
3. Direct work mode
    This work mode allows sending data without invoking any command through
    the slave interface.
Currently only STIG work mode is enabled, remaining work modes will
be added later.

Signed-off-by: Konrad Kociolek <konrad@cadence.com>
Signed-off-by: Jayshri Pawar <jpawar@cadence.com>
Signed-off-by: Parshuram Thombare <pthombar@cadence.com>
---
 drivers/spi/Kconfig            |  12 +
 drivers/spi/Makefile           |   1 +
 drivers/spi/spi-cadence-xspi.c | 627 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 640 insertions(+)
 create mode 100644 drivers/spi/spi-cadence-xspi.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index e71a4c5..9374639 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -228,6 +228,18 @@ config SPI_CADENCE_QUADSPI
 	  device with a Cadence QSPI controller and want to access the
 	  Flash as an MTD device.
 
+config SPI_CADENCE_XSPI
+	tristate "Cadence XSPI controller"
+	depends on (OF || COMPILE_TEST) && HAS_IOMEM
+	depends on SPI_MEM
+	help
+	  Enable support for the Cadence XSPI Flash controller.
+
+	  Cadence XSPI is a specialized controller for connecting an SPI
+	  Flash over upto 8bit wide bus. Enable this option if you have a
+	  device with a Cadence XSPI controller and want to access the
+	  Flash as an MTD device.
+
 config SPI_CLPS711X
 	tristate "CLPS711X host SPI controller"
 	depends on ARCH_CLPS711X || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 13e54c4..93229a8 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_SPI_AR934X)		+= spi-ar934x.o
 obj-$(CONFIG_SPI_ARMADA_3700)		+= spi-armada-3700.o
 obj-$(CONFIG_SPI_ATMEL)			+= spi-atmel.o
 obj-$(CONFIG_SPI_ATMEL_QUADSPI)		+= atmel-quadspi.o
+obj-$(CONFIG_SPI_CADENCE_XSPI)		+= spi-cadence-xspi.o
 obj-$(CONFIG_SPI_AT91_USART)		+= spi-at91-usart.o
 obj-$(CONFIG_SPI_ATH79)			+= spi-ath79.o
 obj-$(CONFIG_SPI_AU1550)		+= spi-au1550.o
diff --git a/drivers/spi/spi-cadence-xspi.c b/drivers/spi/spi-cadence-xspi.c
new file mode 100644
index 0000000..3bc3018
--- /dev/null
+++ b/drivers/spi/spi-cadence-xspi.c
@@ -0,0 +1,627 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Cadence XSPI flash controller driver
+// Copyright (C) 2020-21 Cadence
+
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi-mem.h>
+#include <linux/bitfield.h>
+#include <linux/limits.h>
+#include <linux/log2.h>
+
+#define CDNS_XSPI_MAGIC_NUM_VALUE	0x6522
+#define CDNS_XSPI_MAX_BANKS		8
+#define CDNS_XSPI_NAME			"cadence-xspi"
+
+/*
+ * Note: below are additional auxiliary registers to
+ * configure XSPI controller pin-strap settings
+ */
+
+/* PHY DQ timing register */
+#define CDNS_XSPI_CCP_PHY_DQ_TIMING		0x0000
+
+/* PHY DQS timing register */
+#define CDNS_XSPI_CCP_PHY_DQS_TIMING		0x0004
+
+/* PHY gate loopback control register */
+#define CDNS_XSPI_CCP_PHY_GATE_LPBCK_CTRL	0x0008
+
+/* PHY DLL slave control register */
+#define CDNS_XSPI_CCP_PHY_DLL_SLAVE_CTRL	0x0010
+
+/* DLL PHY control register */
+#define CDNS_XSPI_DLL_PHY_CTRL			0x1034
+
+/* Command registers */
+#define CDNS_XSPI_CMD_REG_0			0x0000
+#define CDNS_XSPI_CMD_REG_1			0x0004
+#define CDNS_XSPI_CMD_REG_2			0x0008
+#define CDNS_XSPI_CMD_REG_3			0x000C
+#define CDNS_XSPI_CMD_REG_4			0x0010
+#define CDNS_XSPI_CMD_REG_5			0x0014
+
+/* Command status registers */
+#define CDNS_XSPI_CMD_STATUS_REG		0x0044
+
+/* Controller status register */
+#define CDNS_XSPI_CTRL_STATUS_REG		0x0100
+#define CDNS_XSPI_INIT_COMPLETED		BIT(16)
+#define CDNS_XSPI_INIT_LEGACY			BIT(9)
+#define CDNS_XSPI_INIT_FAIL			BIT(8)
+#define CDNS_XSPI_CTRL_BUSY			BIT(7)
+
+/* Controller interrupt status register */
+#define CDNS_XSPI_INTR_STATUS_REG		0x0110
+#define CDNS_XSPI_STIG_DONE			BIT(23)
+#define CDNS_XSPI_SDMA_ERROR			BIT(22)
+#define CDNS_XSPI_SDMA_TRIGGER			BIT(21)
+#define CDNS_XSPI_CMD_IGNRD_EN			BIT(20)
+#define CDNS_XSPI_DDMA_TERR_EN			BIT(18)
+#define CDNS_XSPI_CDMA_TREE_EN			BIT(17)
+#define CDNS_XSPI_CTRL_IDLE_EN			BIT(16)
+
+#define CDNS_XSPI_TRD_COMP_INTR_STATUS		0x0120
+#define CDNS_XSPI_TRD_ERR_INTR_STATUS		0x0130
+#define CDNS_XSPI_TRD_ERR_INTR_EN		0x0134
+
+/* Controller interrupt enable register */
+#define CDNS_XSPI_INTR_ENABLE_REG		0x0114
+#define CDNS_XSPI_INTR_EN			BIT(31)
+#define CDNS_XSPI_STIG_DONE_EN			BIT(23)
+#define CDNS_XSPI_SDMA_ERROR_EN			BIT(22)
+#define CDNS_XSPI_SDMA_TRIGGER_EN		BIT(21)
+
+#define CDNS_XSPI_INTR_MASK (CDNS_XSPI_INTR_EN | \
+	CDNS_XSPI_STIG_DONE_EN  | \
+	CDNS_XSPI_SDMA_ERROR_EN | \
+	CDNS_XSPI_SDMA_TRIGGER_EN)
+
+/* Controller config register */
+#define CDNS_XSPI_CTRL_CONFIG_REG		0x0230
+#define CDNS_XSPI_CTRL_WORK_MODE		GENMASK(6, 5)
+
+#define CDNS_XSPI_WORK_MODE_DIRECT		0
+#define CDNS_XSPI_WORK_MODE_STIG		1
+#define CDNS_XSPI_WORK_MODE_ACMD		3
+
+/* SDMA trigger transaction registers */
+#define CDNS_XSPI_SDMA_SIZE_REG			0x0240
+#define CDNS_XSPI_SDMA_TRD_INFO_REG		0x0244
+#define CDNS_XSPI_SDMA_DIR			BIT(8)
+
+/* Controller features register */
+#define CDNS_XSPI_CTRL_FEATURES_REG		0x0F04
+#define CDNS_XSPI_NUM_BANKS			GENMASK(25, 24)
+#define CDNS_XSPI_DMA_DATA_WIDTH		BIT(21)
+#define CDNS_XSPI_NUM_THREADS			GENMASK(3, 0)
+
+/* Controller version register */
+#define CDNS_XSPI_CTRL_VERSION_REG		0x0F00
+#define CDNS_XSPI_MAGIC_NUM			GENMASK(31, 16)
+#define CDNS_XSPI_CTRL_REV			GENMASK(7, 0)
+
+/* STIG Profile 1.0 instruction fields (split into registers) */
+#define CDNS_XSPI_CMD_INSTR_TYPE		GENMASK(6, 0)
+#define CDNS_XSPI_CMD_P1_R1_ADDR0		GENMASK(31, 24)
+#define CDNS_XSPI_CMD_P1_R2_ADDR1		GENMASK(7, 0)
+#define CDNS_XSPI_CMD_P1_R2_ADDR2		GENMASK(15, 8)
+#define CDNS_XSPI_CMD_P1_R2_ADDR3		GENMASK(23, 16)
+#define CDNS_XSPI_CMD_P1_R2_ADDR4		GENMASK(31, 24)
+#define CDNS_XSPI_CMD_P1_R3_ADDR5		GENMASK(7, 0)
+#define CDNS_XSPI_CMD_P1_R3_CMD			GENMASK(23, 16)
+#define CDNS_XSPI_CMD_P1_R3_NUM_ADDR_BYTES	GENMASK(30, 28)
+#define CDNS_XSPI_CMD_P1_R4_ADDR_IOS		GENMASK(1, 0)
+#define CDNS_XSPI_CMD_P1_R4_CMD_IOS		GENMASK(9, 8)
+#define CDNS_XSPI_CMD_P1_R4_BANK		GENMASK(14, 12)
+
+/* STIG data sequence instruction fields (split into registers) */
+#define CDNS_XSPI_CMD_DSEQ_R2_DCNT_L		GENMASK(31, 16)
+#define CDNS_XSPI_CMD_DSEQ_R3_DCNT_H		GENMASK(15, 0)
+#define CDNS_XSPI_CMD_DSEQ_R3_NUM_OF_DUMMY	GENMASK(25, 20)
+#define CDNS_XSPI_CMD_DSEQ_R4_BANK		GENMASK(14, 12)
+#define CDNS_XSPI_CMD_DSEQ_R4_DATA_IOS		GENMASK(9, 8)
+#define CDNS_XSPI_CMD_DSEQ_R4_DIR		BIT(4)
+
+/* STIG command status fields */
+#define CDNS_XSPI_CMD_STATUS_COMPLETED		BIT(15)
+#define CDNS_XSPI_CMD_STATUS_FAILED		BIT(14)
+#define CDNS_XSPI_CMD_STATUS_DQS_ERROR		BIT(3)
+#define CDNS_XSPI_CMD_STATUS_CRC_ERROR		BIT(2)
+#define CDNS_XSPI_CMD_STATUS_BUS_ERROR		BIT(1)
+#define CDNS_XSPI_CMD_STATUS_INV_SEQ_ERROR	BIT(0)
+
+#define CDNS_XSPI_STIG_DONE_FLAG		BIT(0)
+#define CDNS_XSPI_TRD_STATUS			0x0104
+
+/* Helper macros for filling command registers */
+#define CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_1(op, data_phase) ( \
+	FIELD_PREP(CDNS_XSPI_CMD_INSTR_TYPE, (data_phase) ? \
+		CDNS_XSPI_STIG_INSTR_TYPE_1 : CDNS_XSPI_STIG_INSTR_TYPE_0) | \
+	FIELD_PREP(CDNS_XSPI_CMD_P1_R1_ADDR0, (op)->addr.val & 0xff))
+
+#define CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_2(op) ( \
+	FIELD_PREP(CDNS_XSPI_CMD_P1_R2_ADDR1, ((op)->addr.val >> 8)  & 0xFF) | \
+	FIELD_PREP(CDNS_XSPI_CMD_P1_R2_ADDR2, ((op)->addr.val >> 16) & 0xFF) | \
+	FIELD_PREP(CDNS_XSPI_CMD_P1_R2_ADDR3, ((op)->addr.val >> 24) & 0xFF) | \
+	FIELD_PREP(CDNS_XSPI_CMD_P1_R2_ADDR4, ((op)->addr.val >> 32) & 0xFF))
+
+#define CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_3(op) ( \
+	FIELD_PREP(CDNS_XSPI_CMD_P1_R3_ADDR5, ((op)->addr.val >> 40) & 0xFF) | \
+	FIELD_PREP(CDNS_XSPI_CMD_P1_R3_CMD, (op)->cmd.opcode) | \
+	FIELD_PREP(CDNS_XSPI_CMD_P1_R3_NUM_ADDR_BYTES, (op)->addr.nbytes))
+
+#define CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_4(op, chipsel) ( \
+	FIELD_PREP(CDNS_XSPI_CMD_P1_R4_ADDR_IOS, ilog2((op)->addr.buswidth)) | \
+	FIELD_PREP(CDNS_XSPI_CMD_P1_R4_CMD_IOS, ilog2((op)->cmd.buswidth)) | \
+	FIELD_PREP(CDNS_XSPI_CMD_P1_R4_BANK, chipsel))
+
+#define CDNS_XSPI_CMD_FLD_DSEQ_CMD_1(op) \
+	FIELD_PREP(CDNS_XSPI_CMD_INSTR_TYPE, CDNS_XSPI_STIG_INSTR_TYPE_DATA_SEQ)
+
+#define CDNS_XSPI_CMD_FLD_DSEQ_CMD_2(op) \
+	FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R2_DCNT_L, (op)->data.nbytes & 0xFFFF)
+
+#define CDNS_XSPI_CMD_FLD_DSEQ_CMD_3(op) ( \
+	FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R3_DCNT_H, \
+		((op)->data.nbytes >> 16) & 0xffff) | \
+	FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R3_NUM_OF_DUMMY, (op)->dummy.nbytes * 8))
+
+#define CDNS_XSPI_CMD_FLD_DSEQ_CMD_4(op, chipsel) ( \
+	FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R4_BANK, chipsel) | \
+	FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R4_DATA_IOS, ilog2((op)->data.buswidth)) | \
+	FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R4_DIR, \
+		((op)->data.dir == SPI_MEM_DATA_IN) ? \
+		CDNS_XSPI_STIG_CMD_DIR_READ : CDNS_XSPI_STIG_CMD_DIR_WRITE))
+
+enum cdns_xspi_stig_instr_type {
+	CDNS_XSPI_STIG_INSTR_TYPE_0,
+	CDNS_XSPI_STIG_INSTR_TYPE_1,
+	CDNS_XSPI_STIG_INSTR_TYPE_DATA_SEQ = 127,
+};
+
+enum cdns_xspi_sdma_dir {
+	CDNS_XSPI_SDMA_DIR_READ,
+	CDNS_XSPI_SDMA_DIR_WRITE,
+};
+
+enum cdns_xspi_stig_cmd_dir {
+	CDNS_XSPI_STIG_CMD_DIR_READ,
+	CDNS_XSPI_STIG_CMD_DIR_WRITE,
+};
+
+struct cdns_xspi_dev {
+	struct platform_device *pdev;
+	struct device *dev;
+
+	void __iomem *iobase;
+	void __iomem *auxbase;
+	void __iomem *sdmabase;
+
+	int irq;
+	int cur_cs;
+
+	struct completion cmd_complete;
+	struct completion auto_cmd_complete;
+	struct completion sdma_complete;
+	bool sdma_error;
+
+	void *in_buffer;
+	const void *out_buffer;
+
+	u8 hw_num_banks;
+};
+
+static int cdns_xspi_wait_for_controller_idle(struct cdns_xspi_dev *cdns_xspi)
+{
+	u32 ctrl_stat;
+
+	return readl_relaxed_poll_timeout(cdns_xspi->iobase +
+					  CDNS_XSPI_CTRL_STATUS_REG,
+					  ctrl_stat,
+					  ((ctrl_stat &
+					    CDNS_XSPI_CTRL_BUSY) == 0),
+					  100, 1000);
+}
+
+static void cdns_xspi_trigger_command(struct cdns_xspi_dev *cdns_xspi,
+				      u32 cmd_regs[5])
+{
+	writel(cmd_regs[5], cdns_xspi->iobase + CDNS_XSPI_CMD_REG_5);
+	writel(cmd_regs[4], cdns_xspi->iobase + CDNS_XSPI_CMD_REG_4);
+	writel(cmd_regs[3], cdns_xspi->iobase + CDNS_XSPI_CMD_REG_3);
+	writel(cmd_regs[2], cdns_xspi->iobase + CDNS_XSPI_CMD_REG_2);
+	writel(cmd_regs[1], cdns_xspi->iobase + CDNS_XSPI_CMD_REG_1);
+	writel(cmd_regs[0], cdns_xspi->iobase + CDNS_XSPI_CMD_REG_0);
+}
+
+static int cdns_xspi_check_command_status(struct cdns_xspi_dev *cdns_xspi)
+{
+	int ret = 0;
+	u32 cmd_status = readl(cdns_xspi->iobase + CDNS_XSPI_CMD_STATUS_REG);
+
+	if (cmd_status & CDNS_XSPI_CMD_STATUS_COMPLETED) {
+		if ((cmd_status & CDNS_XSPI_CMD_STATUS_FAILED) != 0) {
+			if (cmd_status & CDNS_XSPI_CMD_STATUS_DQS_ERROR) {
+				dev_err(cdns_xspi->dev,
+					"Incorrect DQS pulses detected\n");
+				ret = -EPROTO;
+			}
+			if (cmd_status & CDNS_XSPI_CMD_STATUS_CRC_ERROR) {
+				dev_err(cdns_xspi->dev,
+					"CRC error received\n");
+				ret = -EPROTO;
+			}
+			if (cmd_status & CDNS_XSPI_CMD_STATUS_BUS_ERROR) {
+				dev_err(cdns_xspi->dev,
+					"Error resp on system DMA interface\n");
+				ret = -EPROTO;
+			}
+			if (cmd_status & CDNS_XSPI_CMD_STATUS_INV_SEQ_ERROR) {
+				dev_err(cdns_xspi->dev,
+					"Invalid command sequence detected\n");
+				ret = -EPROTO;
+			}
+		}
+	} else {
+		dev_err(cdns_xspi->dev, "Fatal err - command not completed\n");
+		ret = -EPROTO;
+	}
+
+	return ret;
+}
+
+static void cdns_xspi_set_interrupts(struct cdns_xspi_dev *cdns_xspi,
+				     bool enabled)
+{
+	u32 intr_enable;
+
+	intr_enable = readl(cdns_xspi->iobase + CDNS_XSPI_INTR_ENABLE_REG);
+	if (enabled)
+		intr_enable |= CDNS_XSPI_INTR_MASK;
+	else
+		intr_enable &= ~CDNS_XSPI_INTR_MASK;
+	writel(intr_enable, cdns_xspi->iobase + CDNS_XSPI_INTR_ENABLE_REG);
+}
+
+static int cdns_xspi_controller_init(struct cdns_xspi_dev *cdns_xspi)
+{
+	u32 ctrl_ver;
+	u32 ctrl_features;
+	u16 hw_magic_num;
+
+	ctrl_ver = readl(cdns_xspi->iobase + CDNS_XSPI_CTRL_VERSION_REG);
+	hw_magic_num = FIELD_GET(CDNS_XSPI_MAGIC_NUM, ctrl_ver);
+	if (hw_magic_num != CDNS_XSPI_MAGIC_NUM_VALUE) {
+		dev_err(cdns_xspi->dev,
+			"Incorrect XSPI magic nunber: %x, expected: %x\n",
+			hw_magic_num, CDNS_XSPI_MAGIC_NUM_VALUE);
+		return -EIO;
+	}
+
+	ctrl_features = readl(cdns_xspi->iobase + CDNS_XSPI_CTRL_FEATURES_REG);
+	cdns_xspi->hw_num_banks = FIELD_GET(CDNS_XSPI_NUM_BANKS, ctrl_features);
+	cdns_xspi_set_interrupts(cdns_xspi, false);
+
+	return 0;
+}
+
+static void cdns_xspi_sdma_handle(struct cdns_xspi_dev *cdns_xspi)
+{
+	u32 sdma_size, sdma_trd_info;
+	u8 sdma_dir;
+
+	sdma_size = readl(cdns_xspi->iobase + CDNS_XSPI_SDMA_SIZE_REG);
+	sdma_trd_info = readl(cdns_xspi->iobase + CDNS_XSPI_SDMA_TRD_INFO_REG);
+	sdma_dir = FIELD_GET(CDNS_XSPI_SDMA_DIR, sdma_trd_info);
+
+	switch (sdma_dir) {
+	case CDNS_XSPI_SDMA_DIR_READ:
+		ioread8_rep(cdns_xspi->sdmabase,
+			    cdns_xspi->in_buffer, sdma_size);
+		break;
+
+	case CDNS_XSPI_SDMA_DIR_WRITE:
+		iowrite8_rep(cdns_xspi->sdmabase,
+			     cdns_xspi->out_buffer, sdma_size);
+		break;
+	}
+}
+
+static int cdns_xspi_send_stig_command(struct cdns_xspi_dev *cdns_xspi,
+				       const struct spi_mem_op *op,
+				       bool data_phase)
+{
+	u32 cmd_regs[5];
+	u32 cmd_status;
+	int ret;
+
+	ret = cdns_xspi_wait_for_controller_idle(cdns_xspi);
+	if (ret < 0)
+		return -EIO;
+
+	writel(FIELD_PREP(CDNS_XSPI_CTRL_WORK_MODE, CDNS_XSPI_WORK_MODE_STIG),
+	       cdns_xspi->iobase + CDNS_XSPI_CTRL_CONFIG_REG);
+
+	cdns_xspi_set_interrupts(cdns_xspi, true);
+	cdns_xspi->sdma_error = false;
+
+	memset(cmd_regs, 0, sizeof(cmd_regs));
+	cmd_regs[1] = CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_1(op, data_phase);
+	cmd_regs[2] = CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_2(op);
+	cmd_regs[3] = CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_3(op);
+	cmd_regs[4] = CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_4(op,
+						       cdns_xspi->cur_cs);
+
+	cdns_xspi_trigger_command(cdns_xspi, cmd_regs);
+
+	if (data_phase) {
+		cmd_regs[0] = CDNS_XSPI_STIG_DONE_FLAG;
+		cmd_regs[1] = CDNS_XSPI_CMD_FLD_DSEQ_CMD_1(op);
+		cmd_regs[2] = CDNS_XSPI_CMD_FLD_DSEQ_CMD_2(op);
+		cmd_regs[3] = CDNS_XSPI_CMD_FLD_DSEQ_CMD_3(op);
+		cmd_regs[4] = CDNS_XSPI_CMD_FLD_DSEQ_CMD_4(op,
+							   cdns_xspi->cur_cs);
+
+		cdns_xspi->in_buffer = op->data.buf.in;
+		cdns_xspi->out_buffer = op->data.buf.out;
+
+		cdns_xspi_trigger_command(cdns_xspi, cmd_regs);
+
+		wait_for_completion(&cdns_xspi->sdma_complete);
+		if (cdns_xspi->sdma_error) {
+			cdns_xspi_set_interrupts(cdns_xspi, false);
+			return -EIO;
+		}
+		cdns_xspi_sdma_handle(cdns_xspi);
+	}
+
+	wait_for_completion(&cdns_xspi->cmd_complete);
+	cdns_xspi_set_interrupts(cdns_xspi, false);
+
+	cmd_status = cdns_xspi_check_command_status(cdns_xspi);
+	if (cmd_status)
+		return -EPROTO;
+
+	return 0;
+}
+
+static int cdns_xspi_mem_op(struct cdns_xspi_dev *cdns_xspi,
+			    struct spi_mem *mem,
+			    const struct spi_mem_op *op)
+{
+	enum spi_mem_data_dir dir = op->data.dir;
+
+	if (cdns_xspi->cur_cs != mem->spi->chip_select)
+		cdns_xspi->cur_cs = mem->spi->chip_select;
+
+	return cdns_xspi_send_stig_command(cdns_xspi, op,
+					   (dir != SPI_MEM_NO_DATA));
+}
+
+static int cdns_xspi_mem_op_execute(struct spi_mem *mem,
+				    const struct spi_mem_op *op)
+{
+	struct cdns_xspi_dev *cdns_xspi =
+		spi_master_get_devdata(mem->spi->master);
+	int ret = 0;
+
+	ret = cdns_xspi_mem_op(cdns_xspi, mem, op);
+
+	return ret;
+}
+
+static const struct spi_controller_mem_ops cadence_xspi_mem_ops = {
+	.exec_op = cdns_xspi_mem_op_execute,
+};
+
+static irqreturn_t cdns_xspi_irq_handler(int this_irq, void *dev)
+{
+	struct cdns_xspi_dev *cdns_xspi = dev;
+	u32 irq_status;
+	irqreturn_t result = IRQ_NONE;
+
+	irq_status = readl(cdns_xspi->iobase + CDNS_XSPI_INTR_STATUS_REG);
+	writel(irq_status, cdns_xspi->iobase + CDNS_XSPI_INTR_STATUS_REG);
+
+	if (irq_status &
+	    (CDNS_XSPI_SDMA_ERROR | CDNS_XSPI_SDMA_TRIGGER | CDNS_XSPI_STIG_DONE)) {
+
+		if (irq_status & CDNS_XSPI_SDMA_ERROR) {
+			dev_err(cdns_xspi->dev,
+				"Slave DMA transaction error\n");
+			cdns_xspi->sdma_error = true;
+			complete(&cdns_xspi->sdma_complete);
+		}
+
+		if (irq_status & CDNS_XSPI_SDMA_TRIGGER)
+			complete(&cdns_xspi->sdma_complete);
+
+		if (irq_status & CDNS_XSPI_STIG_DONE)
+			complete(&cdns_xspi->cmd_complete);
+
+		result = IRQ_HANDLED;
+	}
+
+	irq_status = readl(cdns_xspi->iobase + CDNS_XSPI_TRD_COMP_INTR_STATUS);
+	if (irq_status) {
+		writel(irq_status,
+		       cdns_xspi->iobase + CDNS_XSPI_TRD_COMP_INTR_STATUS);
+
+		complete(&cdns_xspi->auto_cmd_complete);
+
+		result = IRQ_HANDLED;
+	}
+
+	return result;
+}
+
+static int cdns_xspi_of_get_plat_data(struct platform_device *pdev)
+{
+	struct device_node *node_prop = pdev->dev.of_node;
+	struct device_node *node_child;
+	unsigned int cs;
+
+	for_each_child_of_node(node_prop, node_child) {
+		if (!of_device_is_available(node_child))
+			continue;
+
+		if (of_property_read_u32(node_child, "reg", &cs)) {
+			dev_err(&pdev->dev, "Couldn't get memory chip select\n");
+			return -ENXIO;
+		} else if (cs >= CDNS_XSPI_MAX_BANKS) {
+			dev_err(&pdev->dev, "reg (cs) parameter value too large\n");
+			return -ENXIO;
+		}
+	}
+
+	return 0;
+}
+
+static void cdns_xspi_print_phy_config(struct cdns_xspi_dev *cdns_xspi)
+{
+	struct device *dev = cdns_xspi->dev;
+
+	dev_info(dev, "PHY configuration\n");
+	dev_info(dev, "   * xspi_dll_phy_ctrl: %08x\n",
+		 readl(cdns_xspi->iobase + CDNS_XSPI_DLL_PHY_CTRL));
+	dev_info(dev, "   * phy_dq_timing: %08x\n",
+		 readl(cdns_xspi->auxbase + CDNS_XSPI_CCP_PHY_DQ_TIMING));
+	dev_info(dev, "   * phy_dqs_timing: %08x\n",
+		 readl(cdns_xspi->auxbase + CDNS_XSPI_CCP_PHY_DQS_TIMING));
+	dev_info(dev, "   * phy_gate_loopback_ctrl: %08x\n",
+		 readl(cdns_xspi->auxbase + CDNS_XSPI_CCP_PHY_GATE_LPBCK_CTRL));
+	dev_info(dev, "   * phy_dll_slave_ctrl: %08x\n",
+		 readl(cdns_xspi->auxbase + CDNS_XSPI_CCP_PHY_DLL_SLAVE_CTRL));
+}
+
+static int cdns_xspi_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct spi_master *master = NULL;
+	struct cdns_xspi_dev *cdns_xspi = NULL;
+	int ret;
+
+	master = devm_spi_alloc_master(dev, sizeof(*cdns_xspi));
+	if (!master)
+		return -ENOMEM;
+
+	master->mode_bits = SPI_3WIRE | SPI_TX_DUAL  | SPI_TX_QUAD  |
+		SPI_RX_DUAL | SPI_RX_QUAD | SPI_TX_OCTAL | SPI_RX_OCTAL |
+		SPI_MODE_0  | SPI_MODE_3;
+
+	master->mem_ops = &cadence_xspi_mem_ops;
+	master->dev.of_node = pdev->dev.of_node;
+	master->bus_num = -1;
+
+	platform_set_drvdata(pdev, master);
+
+	cdns_xspi = spi_master_get_devdata(master);
+	cdns_xspi->pdev = pdev;
+	cdns_xspi->dev = &pdev->dev;
+	cdns_xspi->cur_cs = 0;
+
+	init_completion(&cdns_xspi->cmd_complete);
+	init_completion(&cdns_xspi->auto_cmd_complete);
+	init_completion(&cdns_xspi->sdma_complete);
+
+	ret = cdns_xspi_of_get_plat_data(pdev);
+	if (ret)
+		return -ENODEV;
+
+	cdns_xspi->iobase = devm_platform_ioremap_resource_byname(pdev,
+								  "xspi-iobase");
+	if (IS_ERR(cdns_xspi->iobase)) {
+		dev_err(dev, "Failed to remap controller base address\n");
+		return PTR_ERR(cdns_xspi->iobase);
+	}
+
+	cdns_xspi->sdmabase = devm_platform_ioremap_resource_byname(pdev,
+								    "xspi-sdmabase");
+	if (IS_ERR(cdns_xspi->sdmabase)) {
+		dev_err(dev, "Failed to remap SDMA address\n");
+		return PTR_ERR(cdns_xspi->sdmabase);
+	}
+
+	cdns_xspi->auxbase = devm_platform_ioremap_resource_byname(pdev,
+								   "xspi-auxbase");
+	if (IS_ERR(cdns_xspi->auxbase)) {
+		dev_err(dev, "Failed to remap AUX address\n");
+		return PTR_ERR(cdns_xspi->auxbase);
+	}
+
+	cdns_xspi->irq = platform_get_irq(pdev, 0);
+	if (cdns_xspi->irq < 0) {
+		dev_err(dev, "Failed to get IRQ\n");
+		return -ENXIO;
+	}
+
+	ret = devm_request_irq(dev, cdns_xspi->irq, cdns_xspi_irq_handler,
+			       IRQF_SHARED, pdev->name, cdns_xspi);
+	if (ret) {
+		dev_err(dev, "Failed to request IRQ: %d\n", cdns_xspi->irq);
+		return ret;
+	}
+
+	cdns_xspi_print_phy_config(cdns_xspi);
+
+	ret = cdns_xspi_controller_init(cdns_xspi);
+	if (ret) {
+		dev_err(dev, "Failed to initialize controller\n");
+		return ret;
+	}
+
+	master->num_chipselect = 1 << cdns_xspi->hw_num_banks;
+
+	ret = devm_spi_register_master(dev, master);
+	if (ret) {
+		dev_err(dev, "Failed to register SPI master\n");
+		return ret;
+	}
+
+	dev_info(dev, "Successfully registered SPI master\n");
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id cdns_xspi_of_match[] = {
+	{
+		.compatible = "cdns,xspi-nor",
+	},
+	{ /* end of table */}
+};
+MODULE_DEVICE_TABLE(of, cdns_xspi_of_match);
+#else
+#define cdns_xspi_of_match NULL
+#endif /* CONFIG_OF */
+
+static struct platform_driver cdns_xspi_platform_driver = {
+	.probe          = cdns_xspi_probe,
+	.remove         = NULL,
+	.driver = {
+		.name = CDNS_XSPI_NAME,
+		.of_match_table = cdns_xspi_of_match,
+	},
+};
+
+module_platform_driver(cdns_xspi_platform_driver);
+
+MODULE_DESCRIPTION("Cadence XSPI Controller Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" CDNS_XSPI_NAME);
+MODULE_AUTHOR("Konrad Kociolek <konrad@cadence.com>");
+MODULE_AUTHOR("Jayshri Pawar <jpawar@cadence.com>");
+MODULE_AUTHOR("Parshuram Thombare <pthombar@cadence.com>");
-- 
2.7.4

Re: [PATCH v4 1/2] spi: cadence: add dt-bindings documentation for Cadence XSPI controller

[Rob Herring]

On Mon, Sep 13, 2021 at 02:04:44PM +0200, Parshuram Thombare wrote:
> Add DT binding for Cadence's XSPI controller driver.
> 
> Signed-off-by: Konrad Kociolek <konrad@cadence.com>
> Signed-off-by: Jayshri Pawar <jpawar@cadence.com>
> Signed-off-by: Parshuram Thombare <pthombar@cadence.com>
> ---
>  .../devicetree/bindings/spi/cdns,xspi.yaml         | 77 ++++++++++++++++++++++
>  1 file changed, 77 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/spi/cdns,xspi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/spi/cdns,xspi.yaml b/Documentation/devicetree/bindings/spi/cdns,xspi.yaml
> new file mode 100644
> index 0000000..5ebede1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/cdns,xspi.yaml
> @@ -0,0 +1,77 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright 2020-21 Cadence
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/spi/cdns,xspi.yaml#"
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> +
> +title: Cadence XSPI Controller
> +
> +maintainers:
> +  - Parshuram Thombare <pthombar@cadence.com>
> +
> +description: |
> +  The XSPI controller allows SPI protocol communication in
> +  single, dual, quad or octal wire transmission modes for
> +  read/write access to slaves such as SPI-NOR flash.
> +
> +allOf:
> +  - $ref: "spi-controller.yaml#"
> +
> +properties:
> +  compatible:
> +    const: cdns,xspi-nor
> +
> +  reg:
> +    items:
> +      - description: address and length of the controller register set
> +      - description: address and length of the Slave DMA data port
> +      - description: address and length of the auxiliary registers
> +
> +  reg-names:
> +    items:
> +      - const: xspi-iobase
> +      - const: xspi-sdmabase
> +      - const: xspi-auxbase

'xspi' and 'base' are redundant. So just io, sdma, and aux.

> +
> +  interrupts:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    bus {
> +        #address-cells = <2>;
> +        #size-cells = <2>;
> +
> +        xspi: spi@a0010000 {
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +            compatible = "cdns,xspi-nor";
> +            reg = <0x0 0xa0010000 0x0 0x10000>,
> +                  <0x0 0xb0000000 0x0 0x10000>,
> +                  <0x0 0xa0020000 0x0 0x10000>;

Unless you are really using 64KB of registers, that wastes a bunch of 
virtual space which is limited on 32-bit platforms.

> +            reg-names = "xspi-iobase", "xspi-sdmabase", "xspi-auxbase";
> +            interrupts = <0 90 IRQ_TYPE_LEVEL_HIGH>;
> +            interrupt-parent = <&gic>;
> +
> +            flash@0 {
> +                compatible = "jedec,spi-nor";
> +                spi-max-frequency = <75000000>;
> +                reg = <0>;
> +            };
> +
> +            flash@1 {
> +                compatible = "jedec,spi-nor";
> +                spi-max-frequency = <75000000>;
> +                reg = <1>;
> +            };
> +        };
> +    };
> -- 
> 2.7.4
> 
> 

Re: [PATCH v4 2/2] spi: cadence: add support for Cadence XSPI controller

[Pratyush Yadav]

On 13/09/21 02:06PM, Parshuram Thombare wrote:
> This patch adds driver for Cadence's XSPI controller.
> It supports 3 work modes.
> 1. ACMD (auto command) work mode
>     ACMD name is because it uses auto command engine in the controller.
>     It further has 2 modes PIO and CDMA (command DMA).
>     The CDMA work mode is dedicated for high-performance application
>     where very low software overhead is required. In this mode the
>     Command Engine is programmed by the series of linked descriptors
>     stored in system memory. These descriptors provide commands to execute
>     and store status information for finished commands.
>     The PIO mode work mode is dedicated for single operation where
>     constructing a linked list of descriptors would require too
>     much effort.
> 2. STIG (Software Triggered Instruction Generator) work mode
>     In STIG mode, controller sends low-level instructions to memory.
>     Each instruction is 128-bit width. There is special instruction
>     DataSequence which carries information about data phase.
>     Driver uses Slave DMA interface to transfer data as only this
>     interface can be used in STIG work mode.
> 3. Direct work mode
>     This work mode allows sending data without invoking any command through
>     the slave interface.
> Currently only STIG work mode is enabled, remaining work modes will
> be added later.

Acked-by: Pratyush Yadav <p.yadav@ti.com>

-- 
Regards,
Pratyush Yadav
Texas Instruments Inc.