[PATCH] Add eSPI device driver (flash channel)

From: Manojkiran Eda
Date: Tue Feb 13 2024 - 09:36:28 EST

This patch adds the driver support for the eSPI controller of
Aspeed 5/6th generation SoCs. This controller is a slave device
communicating with a master over Enhanced Serial Peripheral
Interface (eSPI).

eSPI supports 4 channels, namely peripheral, virtual wire,
out-of-band, and flash, and operates at max frequency of 66MHz.

But at the moment, this patch set only supports the flash channel.

Signed-off-by: Manojkiran Eda <manojkiran.eda@xxxxxxxxx>
---
Hello everyone,

I'm presenting a revised version of the eSPI device driver patch series found at the following link:

https://lore.kernel.org/openbmc/20220516005412.4844-1-chiawei_wang@xxxxxxxxxxxxxx/

This update addresses the issues identified during the review process.

While the previous patch series attempted to incorporate support for all four different channels of eSPI,
this new series focuses on upstreaming the flash channel initially, ensuring that all review comments are
duly addressed, before progressing further.

Results:

Successfully conducted a flash update via eSPI.

Note:

This marks my inaugural endeavor in contributing code to the kernel subsystem. I kindly request reviewers
to incorporate as many details as possible in the review comments.
---
.../devicetree/bindings/soc/aspeed/espi.yaml | 125 ++++++
arch/arm/boot/dts/aspeed/aspeed-g6.dtsi | 16 +-
drivers/mtd/mtdcore.c | 2 +-
drivers/soc/aspeed/Kconfig | 10 +
drivers/soc/aspeed/Makefile | 3 +
drivers/soc/aspeed/aspeed-espi-ctrl.c | 197 +++++++++
drivers/soc/aspeed/aspeed-espi-ctrl.h | 169 ++++++++
drivers/soc/aspeed/aspeed-espi-flash.c | 466 +++++++++++++++++++++
drivers/soc/aspeed/aspeed-espi-flash.h | 45 ++
include/uapi/linux/espi/aspeed-espi-ioc.h | 103 +++++
10 files changed, 1134 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/soc/aspeed/espi.yaml b/Documentation/devicetree/bindings/soc/aspeed/espi.yaml
new file mode 100644
index 000000000000..6521a351d18d
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/aspeed/espi.yaml
@@ -0,0 +1,125 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# # Copyright (c) 2021 Aspeed Technology Inc.
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/soc/aspeed/espi.yaml#";
+$schema: "http://devicetree.org/meta-schemas/core.yaml#";
+
+title: Aspeed eSPI Controller
+
+maintainers:
+ - Manojkiran Eda <manojkiran.eda@xxxxxxxxx>
+ - Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
+ - Chia-Wei Wang <chiawei_wang@xxxxxxxxxxxxxx>
+ - Ryan Chen <ryan_chen@xxxxxxxxxxxxxx>
+
+description:
+ Aspeed eSPI controller implements a slave side eSPI endpoint device
+ supporting the four eSPI channels, namely peripheral, virtual wire,
+ out-of-band, and flash.
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - aspeed,ast2500-espi
+ - aspeed,ast2600-espi
+ - const: simple-mfd
+ - const: syscon
+
+ reg:
+ maxItems: 1
+
+ "#address-cells":
+ const: 1
+
+ "#size-cells":
+ const: 1
+
+ ranges: true
+
+patternProperties:
+ "^espi-ctrl@[0-9a-f]+$":
+ type: object
+
+ description: Control of the four basic eSPI channels
+
+ properties:
+ compatible:
+ items:
+ - enum:
+ - aspeed,ast2500-espi-ctrl
+ - aspeed,ast2600-espi-ctrl
+
+ interrupts:
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ flash,dma-mode:
+ type: boolean
+ description: Enable DMA support for eSPI flash channel
+
+ flash,safs-mode:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [ 0, 1, 2 ]
+ default: 0
+ description: Slave-Attached-Sharing-Flash mode, 0->Mix, 1->SW, 2->HW
+
+ required:
+ - compatible
+ - interrupts
+ - clocks
+
+ "^espi-mmbi@[0-9a-f]+$":
+ type: object
+
+ description: Control of the PCH-BMC data exchange over eSPI peripheral memory cycle
+
+ properties:
+ compatible:
+ const: aspeed,ast2600-espi-mmbi
+
+ interrupts:
+ maxItems: 1
+
+ required:
+ - compatible
+ - interrupts
+
+required:
+ - compatible
+ - reg
+ - "#address-cells"
+ - "#size-cells"
+ - ranges
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/clock/ast2600-clock.h>
+
+ espi: espi@1e6ee000 {
+ compatible = "aspeed,ast2600-espi", "simple-mfd", "syscon";
+ reg = <0x1e6ee000 0x1000>;
+
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0x0 0x1e6ee000 0x1000>;
+
+ espi_ctrl: espi-ctrl@0 {
+ compatible = "aspeed,ast2600-espi-ctrl";
+ reg = <0x0 0x800>;
+ interrupts = <GIC_SPI 42 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&syscon ASPEED_CLK_GATE_ESPICLK>;
+ };
+
+ espi_mmbi: espi-mmbi@800 {
+ compatible = "aspeed,ast2600-espi-mmbi";
+ reg = <0x800 0x50>;
+ interrupts = <GIC_SPI 108 IRQ_TYPE_LEVEL_HIGH>;
+ };
+ };
diff --git a/arch/arm/boot/dts/aspeed/aspeed-g6.dtsi b/arch/arm/boot/dts/aspeed/aspeed-g6.dtsi
index c4d1faade8be..08d7a2689086 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-g6.dtsi
+++ b/arch/arm/boot/dts/aspeed/aspeed-g6.dtsi
@@ -453,7 +453,21 @@ video: video@1e700000 {
interrupts = <GIC_SPI 7 IRQ_TYPE_LEVEL_HIGH>;
status = "disabled";
};
-
+ espi: espi@1e6ee000 {
+ compatible = "aspeed,ast2600-espi", "simple-mfd", "syscon";
+ reg = <0x1e6ee000 0x1000>;
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0x0 0x1e6ee000 0x1000>;
+ espi_ctrl: espi-ctrl@0 {
+ compatible = "aspeed,ast2600-espi-ctrl";
+ reg = <0x0 0x800>,<0x0 0x4000000>;
+ reg-names = "espi_ctrl","espi_flash";
+ interrupts = <GIC_SPI 42 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&syscon ASPEED_CLK_GATE_ESPICLK>;
+ status = "disabled";
+ };
+ };
gpio0: gpio@1e780000 {
#gpio-cells = <2>;
gpio-controller;
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index e451b28840d5..cc51c9fb2c1e 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -2560,7 +2560,7 @@ static void __exit cleanup_mtd(void)
idr_destroy(&mtd_idr);
}

-module_init(init_mtd);
+subsys_initcall(init_mtd);
module_exit(cleanup_mtd);

MODULE_LICENSE("GPL");
diff --git a/drivers/soc/aspeed/Kconfig b/drivers/soc/aspeed/Kconfig
index f579ee0b5afa..468f000abc66 100644
--- a/drivers/soc/aspeed/Kconfig
+++ b/drivers/soc/aspeed/Kconfig
@@ -52,6 +52,16 @@ config ASPEED_SOCINFO
help
Say yes to support decoding of ASPEED BMC information.

+config ASPEED_ESPI
+ bool "ASPEED eSPI slave driver"
+ select REGMAP
+ select MFD_SYSCON
+ default n
+ help
+ Enable driver support for the Aspeed eSPI engine. The eSPI engine
+ plays as a slave device in BMC to communicate with the Host over
+ the eSPI interface.
+
endmenu

endif
diff --git a/drivers/soc/aspeed/Makefile b/drivers/soc/aspeed/Makefile
index b35d74592964..a6e2464a08af 100644
--- a/drivers/soc/aspeed/Makefile
+++ b/drivers/soc/aspeed/Makefile
@@ -4,3 +4,6 @@ obj-$(CONFIG_ASPEED_LPC_SNOOP) += aspeed-lpc-snoop.o
obj-$(CONFIG_ASPEED_UART_ROUTING) += aspeed-uart-routing.o
obj-$(CONFIG_ASPEED_P2A_CTRL) += aspeed-p2a-ctrl.o
obj-$(CONFIG_ASPEED_SOCINFO) += aspeed-socinfo.o
+obj-$(CONFIG_ASPEED_ESPI) += aspeed-espi-ctrl.o \
+ aspeed-espi-flash.o
+
diff --git a/drivers/soc/aspeed/aspeed-espi-ctrl.c b/drivers/soc/aspeed/aspeed-espi-ctrl.c
new file mode 100644
index 000000000000..8fa9efee9210
--- /dev/null
+++ b/drivers/soc/aspeed/aspeed-espi-ctrl.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2024 IBM Corporation.
+ */
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/miscdevice.h>
+#include <linux/dma-mapping.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+
+#include "aspeed-espi-ctrl.h"
+#include "aspeed-espi-flash.h"
+
+/**
+ * aspeed_espi_ctrl_isr - function to handle various interrupts
+ * @irq: interrupt line
+ * @arg: pointer to access device registers
+ *
+ * Returns IRQ_HANDLED
+ */
+static irqreturn_t aspeed_espi_ctrl_isr(int irq, void *arg)
+{
+ uint32_t sts;
+ struct aspeed_espi_ctrl *espi_ctrl = (struct aspeed_espi_ctrl *)arg;
+
+ regmap_read(espi_ctrl->map, ESPI_INT_STS, &sts);
+
+ if (sts & ESPI_INT_STS_FLASH_BITS) {
+ aspeed_espi_flash_event(sts, espi_ctrl->flash);
+ regmap_write(espi_ctrl->map, ESPI_INT_STS,
+ sts & ESPI_INT_STS_FLASH_BITS);
+ }
+
+ if (sts & ESPI_INT_STS_HW_RST_DEASSERT) {
+ aspeed_espi_flash_enable(espi_ctrl->flash);
+
+ regmap_write(espi_ctrl->map, ESPI_SYSEVT_INT_T0, 0x0);
+ regmap_write(espi_ctrl->map, ESPI_SYSEVT_INT_T1, 0x0);
+ regmap_write(espi_ctrl->map, ESPI_SYSEVT_INT_EN, 0xffffffff);
+
+ regmap_write(espi_ctrl->map, ESPI_SYSEVT1_INT_T0, 0x1);
+ regmap_write(espi_ctrl->map, ESPI_SYSEVT1_INT_EN, 0x1);
+
+ regmap_update_bits(espi_ctrl->map, ESPI_INT_EN,
+ ESPI_INT_EN_HW_RST_DEASSERT,
+ ESPI_INT_EN_HW_RST_DEASSERT);
+
+ regmap_update_bits(
+ espi_ctrl->map, ESPI_SYSEVT,
+ ESPI_SYSEVT_SLV_BOOT_STS | ESPI_SYSEVT_SLV_BOOT_DONE,
+ ESPI_SYSEVT_SLV_BOOT_STS | ESPI_SYSEVT_SLV_BOOT_DONE);
+
+ regmap_write(espi_ctrl->map, ESPI_INT_STS,
+ ESPI_INT_STS_HW_RST_DEASSERT);
+ }
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * aspeed_espi_ctrl_probe - function to probe the platform driver
+ * @pdev: platform device
+ *
+ * Returns 0 on success, -ENOMEM on error
+ */
+static int aspeed_espi_ctrl_probe(struct platform_device *pdev)
+{
+ int rc = 0;
+ struct aspeed_espi_ctrl *espi_ctrl;
+ struct device *dev = &pdev->dev;
+
+ espi_ctrl = devm_kzalloc(dev, sizeof(*espi_ctrl), GFP_KERNEL);
+ if (!espi_ctrl)
+ return -ENOMEM;
+
+ espi_ctrl->model = of_device_get_match_data(dev);
+
+ espi_ctrl->map = syscon_node_to_regmap(dev->parent->of_node);
+ if (IS_ERR(espi_ctrl->map)) {
+ dev_err(dev, "cannot get remap\n");
+ return PTR_ERR(espi_ctrl->map);
+ }
+
+ espi_ctrl->irq = platform_get_irq(pdev, 0);
+ if (espi_ctrl->irq < 0)
+ return espi_ctrl->irq;
+
+ espi_ctrl->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(espi_ctrl->clk)) {
+ dev_err(dev, "cannot get clock\n");
+ return PTR_ERR(espi_ctrl->clk);
+ }
+
+ rc = clk_prepare_enable(espi_ctrl->clk);
+ if (rc) {
+ dev_err(dev, "cannot enable clock\n");
+ return rc;
+ }
+
+ /*
+ * This takes care of deferred probe , incase the mtd core
+ * subsystem is not probed yet.
+ */
+ espi_ctrl->flash = aspeed_espi_flash_alloc(dev, espi_ctrl);
+ if (IS_ERR(espi_ctrl->flash)) {
+ dev_err(dev, "failed to allocate flash channel\n");
+ pr_info("flash alloc failed with return code %ld\n",
+ PTR_ERR(espi_ctrl->flash));
+ return PTR_ERR(espi_ctrl->flash);
+ }
+
+ regmap_write(espi_ctrl->map, ESPI_SYSEVT_INT_T0, 0x0);
+ regmap_write(espi_ctrl->map, ESPI_SYSEVT_INT_T1, 0x0);
+ regmap_write(espi_ctrl->map, ESPI_SYSEVT_INT_EN, 0xffffffff);
+
+ regmap_write(espi_ctrl->map, ESPI_SYSEVT1_INT_T0, 0x1);
+ regmap_write(espi_ctrl->map, ESPI_SYSEVT1_INT_EN, 0x1);
+
+ rc = devm_request_irq(dev, espi_ctrl->irq, aspeed_espi_ctrl_isr, 0,
+ DEVICE_NAME, espi_ctrl);
+ if (rc) {
+ dev_err(dev, "failed to request IRQ\n");
+ return rc;
+ }
+
+ // clear the interrupt enable register
+ regmap_write(espi_ctrl->map, ESPI_INT_EN_CLR, 0x7fffffff);
+
+ // Disable the interrupts in all channels except flash channel
+ regmap_update_bits(espi_ctrl->map, ESPI_INT_EN,
+ ESPI_INT_EN_FLASH_BITS | ESPI_INT_EN_HW_RST_DEASSERT,
+ ESPI_INT_EN_FLASH_BITS |
+ ESPI_INT_STS_HW_RST_DEASSERT);
+
+ dev_set_drvdata(dev, espi_ctrl);
+
+ dev_info(dev, "module loaded\n");
+
+ return 0;
+}
+
+/**
+ * aspeed_espi_ctrl_remove - Release the driver
+ * @pdev: the platform device
+ *
+ * Returns 0
+ */
+static int aspeed_espi_ctrl_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct aspeed_espi_ctrl *espi_ctrl = dev_get_drvdata(dev);
+
+ aspeed_espi_flash_free(dev, espi_ctrl->flash);
+
+ return 0;
+}
+
+static const struct aspeed_espi_model ast2500_model = {
+ .version = ESPI_AST2500,
+};
+
+static const struct aspeed_espi_model ast2600_model = {
+ .version = ESPI_AST2600,
+};
+
+static const struct of_device_id aspeed_espi_ctrl_of_matches[] = {
+ { .compatible = "aspeed,ast2500-espi-ctrl", .data = &ast2500_model },
+ { .compatible = "aspeed,ast2600-espi-ctrl", .data = &ast2600_model },
+ {},
+};
+MODULE_DEVICE_TABLE(of, aspeed_espi_ctrl_of_matches);
+
+static struct platform_driver aspeed_espi_ctrl_driver = {
+ .driver = {
+ .name = DEVICE_NAME,
+ .of_match_table = aspeed_espi_ctrl_of_matches,
+ },
+ .probe = aspeed_espi_ctrl_probe,
+ .remove = aspeed_espi_ctrl_remove,
+};
+
+module_platform_driver(aspeed_espi_ctrl_driver);
+
+MODULE_AUTHOR("Manojkiran Eda <manojkiran.eda@xxxxxxxxx>");
+MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>");
+MODULE_AUTHOR("Chia-Wei Wang <chiawei_wang@xxxxxxxxxxxxxx>");
+MODULE_AUTHOR("Ryan Chen <ryan_chen@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Control of Aspeed eSPI Slave Device");
+MODULE_LICENSE("GPL");
diff --git a/drivers/soc/aspeed/aspeed-espi-ctrl.h b/drivers/soc/aspeed/aspeed-espi-ctrl.h
new file mode 100644
index 000000000000..3e20cbebf8b2
--- /dev/null
+++ b/drivers/soc/aspeed/aspeed-espi-ctrl.h
@@ -0,0 +1,169 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2024 IBM Corporation.
+ */
+#ifndef _ASPEED_ESPI_CTRL_H_
+#define _ASPEED_ESPI_CTRL_H_
+
+#include <linux/bits.h>
+
+#define DEVICE_NAME "aspeed-espi-ctrl"
+
+/**
+ * enum aspeed_espi_version - Enumeration to capture aspeed versions that this
+ * driver supports
+ * @ESPI_AST2500: eSPI for AST2500 Model
+ * @ESPI_AST2600: eSPI for AST2600 Model
+ *
+ * This enumeration captures various aspeed models that this driver supports
+ */
+
+enum aspeed_espi_version {
+ ESPI_AST2500,
+ ESPI_AST2600,
+};
+
+/**
+ * struct aspeed_espi_model - structure to capture version of espi
+ * @version: espi version
+ *
+ * Structure to capture version of eSPI
+ */
+struct aspeed_espi_model {
+ uint32_t version;
+};
+
+/**
+ * struct aspeed_espi_ctrl - structure to group various channels of the driver
+ * @dev: platform device pointer
+ * @map: register map for the device
+ * @clk: clock for the device
+ * @irq: interrupt request
+ * @flash: pointer to flash channel of eSPI
+ * @model: pointer to version of eSPI
+ *
+ * Structure to capture version of eSPI
+ */
+struct aspeed_espi_ctrl {
+ struct device *dev;
+ struct regmap *map;
+ struct clk *clk;
+ int irq;
+ struct aspeed_espi_flash *flash;
+ const struct aspeed_espi_model *model;
+};
+
+/* eSPI register offset */
+#define ESPI_CTRL 0x000
+#define ESPI_CTRL_FLASH_TX_DMA_EN BIT(23)
+#define ESPI_CTRL_FLASH_RX_DMA_EN BIT(22)
+#define ESPI_CTRL_FLASH_SW_MODE_MASK GENMASK(11, 10)
+#define ESPI_CTRL_FLASH_SW_MODE_SHIFT 10
+#define ESPI_CTRL_FLASH_SW_RDY BIT(7)
+
+#define ESPI_STS 0x004
+#define ESPI_CTRL_FLASH_CHAN_RDY BIT(6)
+
+#define ESPI_INT_STS 0x008
+#define ESPI_INT_STS_HW_RST_DEASSERT BIT(31)
+#define ESPI_INT_STS_FLASH_TX_ERR BIT(21)
+#define ESPI_INT_STS_FLASH_TX_ABT BIT(19)
+#define ESPI_INT_STS_FLASH_RX_ABT BIT(15)
+#define ESPI_INT_STS_FLASH_TX_CMPLT BIT(7)
+#define ESPI_INT_STS_FLASH_RX_CMPLT BIT(6)
+#define ESPI_INT_EN 0x00c
+#define ESPI_INT_EN_HW_RST_DEASSERT BIT(31)
+#define ESPI_INT_EN_FLASH_TX_ERR BIT(21)
+#define ESPI_INT_EN_FLASH_TX_ABT BIT(19)
+#define ESPI_INT_EN_FLASH_RX_ABT BIT(15)
+#define ESPI_INT_EN_FLASH_TX_CMPLT BIT(7)
+#define ESPI_INT_EN_FLASH_RX_CMPLT BIT(6)
+#define ESPI_INT_EN_CLR 0x0fc
+#define ESPI_FLASH_RX_DMA 0x060
+#define ESPI_FLASH_RX_CTRL 0x064
+#define ESPI_FLASH_RX_CTRL_PEND_SERV BIT(31)
+#define ESPI_FLASH_RX_CTRL_LEN_MASK GENMASK(23, 12)
+#define ESPI_FLASH_RX_CTRL_LEN_SHIFT 12
+#define ESPI_FLASH_RX_CTRL_TAG_MASK GENMASK(11, 8)
+#define ESPI_FLASH_RX_CTRL_TAG_SHIFT 8
+#define ESPI_FLASH_RX_CTRL_CYC_MASK GENMASK(7, 0)
+#define ESPI_FLASH_RX_CTRL_CYC_SHIFT 0
+#define ESPI_FLASH_RX_PORT 0x068
+#define ESPI_FLASH_TX_DMA 0x070
+#define ESPI_FLASH_TX_CTRL 0x074
+#define ESPI_FLASH_TX_CTRL_TRIGGER BIT(31)
+#define ESPI_FLASH_TX_CTRL_LEN_MASK GENMASK(23, 12)
+#define ESPI_FLASH_TX_CTRL_LEN_SHIFT 12
+#define ESPI_FLASH_TX_CTRL_TAG_MASK GENMASK(11, 8)
+#define ESPI_FLASH_TX_CTRL_TAG_SHIFT 8
+#define ESPI_FLASH_TX_CTRL_CYC_MASK GENMASK(7, 0)
+#define ESPI_FLASH_TX_CTRL_CYC_SHIFT 0
+#define ESPI_FLASH_TX_PORT 0x078
+#define ESPI_CTRL2 0x080
+#define ESPI_CTRL2_MEMCYC_RD_DIS BIT(6)
+#define ESPI_CTRL2_MEMCYC_WR_DIS BIT(4)
+#define ESPI_SYSEVT_INT_EN 0x094
+#define ESPI_SYSEVT 0x098
+#define ESPI_SYSEVT_HOST_RST_ACK BIT(27)
+#define ESPI_SYSEVT_RST_CPU_INIT BIT(26)
+#define ESPI_SYSEVT_SLV_BOOT_STS BIT(23)
+#define ESPI_SYSEVT_NON_FATAL_ERR BIT(22)
+#define ESPI_SYSEVT_FATAL_ERR BIT(21)
+#define ESPI_SYSEVT_SLV_BOOT_DONE BIT(20)
+#define ESPI_SYSEVT_NMI_OUT BIT(10)
+#define ESPI_SYSEVT_SMI_OUT BIT(9)
+#define ESPI_SYSEVT_HOST_RST_WARN BIT(8)
+#define ESPI_SYSEVT_PLTRSTN BIT(5)
+#define ESPI_SYSEVT_SUSPEND BIT(4)
+#define ESPI_SYSEVT_S5_SLEEP BIT(2)
+#define ESPI_SYSEVT_S4_SLEEP BIT(1)
+#define ESPI_SYSEVT_S3_SLEEP BIT(0)
+#define ESPI_GEN_CAP_N_CONF 0x0a0
+#define ESPI_CH0_CAP_N_CONF 0x0a4
+#define ESPI_CH1_CAP_N_CONF 0x0a8
+#define ESPI_CH2_CAP_N_CONF 0x0ac
+#define ESPI_CH3_CAP_N_CONF 0x0b0
+#define ESPI_CH3_CAP_N_CONF_ERASE_MASK GENMASK(4, 2)
+#define ESPI_CH3_CAP_N_CONF_ERASE_SHIFT 2
+#define ESPI_CH3_CAP_N_CONF_ERASE_SIZE_4KB 1
+#define ESPI_CH3_CAP_N_CONF_ERASE_SIZE_64KB 2
+#define ESPI_CH3_CAP_N_CONF_ERASE_SIZE_4KB_64KB 3
+#define ESPI_CH3_CAP_N_CONF_ERASE_SIZE_128KB 4
+#define ESPI_CH3_CAP_N_CONF_ERASE_SIZE_256KB 5
+#define ESPI_CH3_CAP_N_CONF2 0x0b4
+#define ESPI_SYSEVT1_INT_EN 0x100
+#define ESPI_SYSEVT1 0x104
+#define ESPI_SYSEVT1_SUSPEND_ACK BIT(20)
+#define ESPI_SYSEVT1_SUSPEND_WARN BIT(0)
+#define ESPI_SYSEVT_INT_T0 0x110
+#define ESPI_SYSEVT_INT_T1 0x114
+#define ESPI_SYSEVT_INT_T2 0x118
+#define ESPI_SYSEVT_INT_T2_HOST_RST_WARN ESPI_SYSEVT_HOST_RST_WARN
+#define ESPI_SYSEVT_INT_STS 0x11c
+#define ESPI_SYSEVT_INT_STS_NMI_OUT ESPI_SYSEVT_NMI_OUT
+#define ESPI_SYSEVT_INT_STS_SMI_OUT ESPI_SYSEVT_SMI_OUT
+#define ESPI_SYSEVT_INT_STS_HOST_RST_WARN ESPI_SYSEVT_HOST_RST_WARN
+#define ESPI_SYSEVT_INT_STS_PLTRSTN ESPI_SYSEVT_PLTRSTN
+#define ESPI_SYSEVT_INT_STS_SUSPEND ESPI_SYSEVT_SUSPEND
+#define ESPI_SYSEVT_INT_STS_S5_SLEEP ESPI_SYSEVT_INT_S5_SLEEP
+#define ESPI_SYSEVT_INT_STS_S4_SLEEP ESPI_SYSEVT_INT_S4_SLEEP
+#define ESPI_SYSEVT_INT_STS_S3_SLEEP ESPI_SYSEVT_INT_S3_SLEEP
+#define ESPI_SYSEVT1_INT_T0 0x120
+#define ESPI_SYSEVT1_INT_T1 0x124
+#define ESPI_SYSEVT1_INT_T2 0x128
+#define ESPI_SYSEVT1_INT_STS 0x12c
+#define ESPI_SYSEVT1_INT_STS_SUSPEND_WARN ESPI_SYSEVT1_SUSPEND_WARN
+
+/* collect ESPI_INT_STS bits of eSPI channels for convenience */
+#define ESPI_INT_STS_FLASH_BITS \
+ (ESPI_INT_STS_FLASH_TX_ERR | ESPI_INT_STS_FLASH_TX_ABT | \
+ ESPI_INT_STS_FLASH_RX_ABT | ESPI_INT_STS_FLASH_TX_CMPLT | \
+ ESPI_INT_STS_FLASH_RX_CMPLT)
+
+/* collect ESPI_INT_EN bits of eSPI channels for convenience */
+#define ESPI_INT_EN_FLASH_BITS \
+ (ESPI_INT_EN_FLASH_TX_ERR | ESPI_INT_EN_FLASH_TX_ABT | \
+ ESPI_INT_EN_FLASH_RX_ABT | ESPI_INT_EN_FLASH_TX_CMPLT | \
+ ESPI_INT_EN_FLASH_RX_CMPLT)
+
+#endif
diff --git a/drivers/soc/aspeed/aspeed-espi-flash.c b/drivers/soc/aspeed/aspeed-espi-flash.c
new file mode 100644
index 000000000000..d3cf5011426e
--- /dev/null
+++ b/drivers/soc/aspeed/aspeed-espi-flash.c
@@ -0,0 +1,466 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2023 IBM Corporation
+ */
+#include <linux/fs.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/miscdevice.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+#include <linux/miscdevice.h>
+#include <linux/dma-mapping.h>
+
+#include "linux/espi/aspeed-espi-ioc.h"
+#include "aspeed-espi-ctrl.h"
+#include "aspeed-espi-flash.h"
+
+static long aspeed_espi_flash_rx(uint8_t *cyc, uint16_t *len, uint32_t *addr,
+ uint8_t *pkt, size_t *pkt_len,
+ struct aspeed_espi_flash *espi_flash)
+{
+ unsigned long flags;
+ uint32_t reg, rx_pkt_len, addr_be;
+ struct aspeed_espi_ctrl *espi_ctrl = espi_flash->ctrl;
+ void *rx_virt_ptr;
+ ulong to;
+ int ret;
+
+ spin_lock_irqsave(&espi_flash->spinlock, flags);
+
+ to = msecs_to_jiffies(100);
+ ret = wait_event_interruptible_lock_irq_timeout(
+ espi_flash->wq, espi_flash->rx_sts, espi_flash->spinlock, to);
+
+ spin_unlock_irqrestore(&espi_flash->spinlock, flags);
+
+ if (ret == -ERESTARTSYS)
+ return -EINTR;
+ else if (!ret)
+ return -ETIMEDOUT;
+ else if (espi_flash->rx_sts & ESPI_INT_STS_FLASH_RX_ABT)
+ return -EFAULT;
+ else
+ ret = 0;
+
+ /* common header (i.e. cycle type, tag, and length) is taken by HW */
+ regmap_read(espi_ctrl->map, ESPI_FLASH_RX_CTRL, &reg);
+ *cyc = (reg & ESPI_FLASH_RX_CTRL_CYC_MASK) >>
+ ESPI_FLASH_RX_CTRL_CYC_SHIFT;
+ *len = (reg & ESPI_FLASH_RX_CTRL_LEN_MASK) >>
+ ESPI_FLASH_RX_CTRL_LEN_SHIFT;
+
+ /*
+ * calculate the length of the rest part of the
+ * eSPI packet to be read from HW and copied to
+ * user space.
+ */
+ switch (*cyc) {
+ case ESPI_FLASH_READ:
+ case ESPI_FLASH_WRITE:
+ case ESPI_FLASH_ERASE:
+ rx_virt_ptr = espi_flash->dma.rx_virt + sizeof(addr_be);
+ rx_pkt_len = (*len) ? *len : ESPI_PLD_LEN_MAX;
+
+ if (addr) {
+ memcpy(&addr_be, espi_flash->dma.rx_virt,
+ sizeof(addr_be));
+ *addr = ntohl(addr_be);
+ }
+
+ break;
+ case ESPI_FLASH_SUC_CMPLT_D_MIDDLE:
+ case ESPI_FLASH_SUC_CMPLT_D_FIRST:
+ case ESPI_FLASH_SUC_CMPLT_D_LAST:
+ case ESPI_FLASH_SUC_CMPLT_D_ONLY:
+ rx_pkt_len = (*len) ? *len : ESPI_PLD_LEN_MAX;
+ rx_virt_ptr = espi_flash->dma.rx_virt;
+ break;
+ case ESPI_FLASH_SUC_CMPLT:
+ case ESPI_FLASH_UNSUC_CMPLT:
+ case ESPI_FLASH_UNSUC_CMPLT_ONLY:
+ /* No data received */
+ rx_pkt_len = 0;
+ rx_virt_ptr = NULL;
+ break;
+ default:
+ rx_pkt_len = 0;
+ ret = -EFAULT;
+ }
+ if (pkt_len)
+ *pkt_len = rx_pkt_len;
+
+ if (rx_pkt_len && pkt_len && pkt) {
+ if (*pkt_len >= rx_pkt_len)
+ memcpy(pkt, rx_virt_ptr, rx_pkt_len);
+ else
+ ret = -EINVAL;
+ }
+
+ spin_lock_irqsave(&espi_flash->spinlock, flags);
+
+ regmap_write_bits(espi_ctrl->map, ESPI_FLASH_RX_CTRL,
+ ESPI_FLASH_RX_CTRL_PEND_SERV,
+ ESPI_FLASH_RX_CTRL_PEND_SERV);
+
+ espi_flash->rx_sts = 0;
+
+ spin_unlock_irqrestore(&espi_flash->spinlock, flags);
+ return ret;
+}
+
+static long
+aspeed_espi_flash_rx_get_completion(struct aspeed_espi_flash *espi_flash)
+{
+ uint8_t cyc;
+ uint16_t len;
+ int ret;
+
+ ret = aspeed_espi_flash_rx(&cyc, &len, NULL, NULL, 0, espi_flash);
+ if (ret)
+ return ret;
+
+ if (cyc != ESPI_FLASH_SUC_CMPLT) {
+ dev_notice("eSPI Rx response was not successful\n");
+ return -EFAULT;
+ }
+ return 0;
+}
+
+static long aspeed_espi_flash_put_tx(uint8_t cyc, uint16_t len, uint32_t addr,
+ const uint8_t *pkt, size_t pkt_len,
+ struct aspeed_espi_flash *espi_flash)
+{
+ struct aspeed_espi_ctrl *espi_ctrl = espi_flash->ctrl;
+ unsigned long flags;
+ uint32_t reg, addr_be;
+ ulong to;
+ int ret = 0;
+
+ /* Test if flash channel is ready */
+ regmap_read(espi_ctrl->map, ESPI_STS, &reg);
+ if (!(reg & ESPI_CTRL_FLASH_CHAN_RDY)) {
+ dev_notice("eSPI flash channel not ready\n");
+ return -EIO;
+ }
+
+ /* Test if TX ready */
+ regmap_read(espi_ctrl->map, ESPI_FLASH_TX_CTRL, &reg);
+ if (reg & ESPI_FLASH_TX_CTRL_TRIGGER) {
+ dev_notice("eSPI Tx operation still pending\n");
+ return -EBUSY;
+ }
+
+ /*
+ * common header (i.e. cycle type, tag, and length)
+ * part is written to HW registers
+ */
+ addr_be = htonl(addr);
+ memcpy(espi_flash->dma.tx_virt, &addr_be, sizeof(addr_be));
+ if (pkt && pkt_len)
+ memcpy(espi_flash->dma.tx_virt + sizeof(addr_be), pkt, pkt_len);
+
+ dma_wmb();
+
+ spin_lock_irqsave(&espi_flash->spinlock, flags);
+ espi_flash->tx_sts = 0;
+ espi_flash->rx_sts = 0;
+
+ reg = ((cyc << ESPI_FLASH_TX_CTRL_CYC_SHIFT) &
+ ESPI_FLASH_TX_CTRL_CYC_MASK) |
+ ((len << ESPI_FLASH_TX_CTRL_LEN_SHIFT) &
+ ESPI_FLASH_TX_CTRL_LEN_MASK) |
+ ESPI_FLASH_TX_CTRL_TRIGGER;
+
+ regmap_write(espi_ctrl->map, ESPI_FLASH_TX_CTRL, reg);
+
+ to = msecs_to_jiffies(100);
+ ret = wait_event_interruptible_lock_irq_timeout(
+ espi_flash->wq, espi_flash->tx_sts, espi_flash->spinlock, to);
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+ else if (!ret) {
+ dev_notice("eSPI Tx operation not processed within 100msec\n");
+ ret = -ETIMEDOUT;
+ } else if (espi_flash->tx_sts &
+ (ESPI_INT_STS_FLASH_TX_ERR | ESPI_INT_STS_FLASH_TX_ABT)) {
+ dev_notice("eSPI Tx operation declined by remote\n");
+
+ ret = -EFAULT;
+ } else
+ ret = 0;
+
+ spin_unlock_irqrestore(&espi_flash->spinlock, flags);
+ return ret;
+}
+
+void aspeed_espi_flash_event(uint32_t sts, struct aspeed_espi_flash *espi_flash)
+{
+ unsigned long flags;
+
+ if (!(sts & ESPI_INT_STS_FLASH_BITS))
+ return;
+
+ spin_lock_irqsave(&espi_flash->spinlock, flags);
+ espi_flash->rx_sts |=
+ sts & (ESPI_INT_STS_FLASH_RX_ABT | ESPI_INT_STS_FLASH_RX_CMPLT);
+ espi_flash->tx_sts |=
+ sts & (ESPI_INT_STS_FLASH_TX_ERR | ESPI_INT_STS_FLASH_TX_ABT |
+ ESPI_INT_STS_FLASH_TX_CMPLT);
+ spin_unlock_irqrestore(&espi_flash->spinlock, flags);
+ wake_up_interruptible(&espi_flash->wq);
+}
+
+static int aspeed_espi_flash_erase(struct mtd_info *mtd,
+ struct erase_info *instr)
+{
+ struct aspeed_espi_flash *espi_flash = mtd->priv;
+ int ret = 0;
+
+ /* Sanity checks */
+ if ((uint32_t)instr->len % espi_flash->mtd.erasesize)
+ return -EINVAL;
+
+ if ((uint32_t)instr->addr % espi_flash->mtd.erasesize)
+ return -EINVAL;
+
+ mutex_lock(&espi_flash->lock);
+
+ while (instr->len) {
+ ret = aspeed_espi_flash_put_tx(ESPI_FLASH_ERASE,
+ espi_flash->erase_mask,
+ instr->addr, NULL, 0,
+ espi_flash);
+ if (ret)
+ goto unlock_mtx_n_out;
+
+ ret = aspeed_espi_flash_rx_get_completion(espi_flash);
+ if (ret)
+ goto unlock_mtx_n_out;
+
+ instr->len -= espi_flash->mtd.erasesize;
+ instr->addr += espi_flash->mtd.erasesize;
+ }
+
+unlock_mtx_n_out:
+ instr->fail_addr = instr->addr;
+
+ mutex_unlock(&espi_flash->lock);
+ return ret;
+}
+
+static int aspeed_espi_flash_read(struct mtd_info *mtd, loff_t from, size_t len,
+ size_t *retlen, u_char *buf)
+{
+ struct aspeed_espi_flash *espi_flash = mtd->priv;
+ uint16_t len_pt, len_rx;
+ size_t pkt_len;
+ uint8_t cyc;
+ int ret = 0;
+
+ mutex_lock(&espi_flash->lock);
+
+ while (len) {
+ len_pt = (len > ESPI_PLD_LEN_MIN) ? ESPI_PLD_LEN_MIN : len;
+
+ ret = aspeed_espi_flash_put_tx(ESPI_FLASH_READ, len_pt, from,
+ NULL, 0, espi_flash);
+ if (ret)
+ goto unlock_mtx_n_out;
+
+ pkt_len = len_pt;
+ len_rx = 0;
+ cyc = 0;
+ ret = aspeed_espi_flash_rx(&cyc, &len_rx, NULL, buf, &pkt_len,
+ espi_flash);
+ if (ret)
+ goto unlock_mtx_n_out;
+
+ if (cyc != ESPI_FLASH_SUC_CMPLT_D_ONLY) {
+ dev_notice("eSPI Rx response was not successful\n");
+ ret = -EFAULT;
+ goto unlock_mtx_n_out;
+ }
+ if (pkt_len != len_pt) {
+ dev_notice("eSPI Rx response has unexpected data length\n");
+ ret = -ENODATA;
+ goto unlock_mtx_n_out;
+ }
+
+ len -= len_pt;
+ buf += len_pt;
+ from += len_pt;
+ *retlen += len_pt;
+ }
+
+unlock_mtx_n_out:
+ mutex_unlock(&espi_flash->lock);
+ return ret;
+}
+
+static int aspeed_espi_flash_write(struct mtd_info *mtd, loff_t to, size_t len,
+ size_t *retlen, const u_char *buf)
+{
+ struct aspeed_espi_flash *espi_flash = mtd->priv;
+ uint16_t len_pt;
+ int ret = 0;
+
+ mutex_lock(&espi_flash->lock);
+
+ while (len) {
+ len_pt = (len > ESPI_PLD_LEN_MIN) ? ESPI_PLD_LEN_MIN : len;
+
+ ret = aspeed_espi_flash_put_tx(ESPI_FLASH_WRITE, len_pt, to,
+ buf, len_pt, espi_flash);
+ if (ret)
+ goto unlock_mtx_n_out;
+
+ ret = aspeed_espi_flash_rx_get_completion(espi_flash);
+ if (ret)
+ goto unlock_mtx_n_out;
+
+ len -= len_pt;
+ buf += len_pt;
+ to += len_pt;
+ *retlen += len_pt;
+ }
+
+unlock_mtx_n_out:
+ mutex_unlock(&espi_flash->lock);
+ return ret;
+}
+
+void aspeed_espi_flash_enable(struct aspeed_espi_flash *espi_flash)
+{
+ struct aspeed_espi_flash_dma *dma = &espi_flash->dma;
+ struct aspeed_espi_ctrl *espi_ctrl = espi_flash->ctrl;
+
+ regmap_update_bits(espi_ctrl->map, ESPI_CTRL,
+ ESPI_CTRL_FLASH_SW_MODE_MASK, 0);
+
+ /* Enable DMA transfers */
+ regmap_write(espi_ctrl->map, ESPI_FLASH_TX_DMA, dma->tx_addr);
+ regmap_write(espi_ctrl->map, ESPI_FLASH_RX_DMA, dma->rx_addr);
+ regmap_update_bits(
+ espi_ctrl->map, ESPI_CTRL,
+ ESPI_CTRL_FLASH_TX_DMA_EN | ESPI_CTRL_FLASH_RX_DMA_EN,
+ ESPI_CTRL_FLASH_TX_DMA_EN | ESPI_CTRL_FLASH_RX_DMA_EN);
+
+ /* Enable interrupts */
+ regmap_write(espi_ctrl->map, ESPI_INT_STS, ESPI_INT_STS_FLASH_BITS);
+
+ regmap_update_bits(espi_ctrl->map, ESPI_INT_EN, ESPI_INT_EN_FLASH_BITS,
+ ESPI_INT_EN_FLASH_BITS);
+
+ /* Set Flash Channel Software Ready */
+ regmap_update_bits(espi_ctrl->map, ESPI_CTRL, ESPI_CTRL_FLASH_SW_RDY,
+ ESPI_CTRL_FLASH_SW_RDY);
+}
+
+void *aspeed_espi_flash_alloc(struct device *dev,
+ struct aspeed_espi_ctrl *espi_ctrl)
+{
+ int ret, index;
+ struct aspeed_espi_flash_dma *dma;
+ struct mtd_info *mtd;
+ struct aspeed_espi_flash *espi_flash;
+ struct resource res;
+ u32 reg;
+
+ espi_flash =
+ devm_kzalloc(dev, sizeof(struct aspeed_espi_flash), GFP_KERNEL);
+ if (!espi_flash)
+ return ERR_PTR(-ENOMEM);
+
+ espi_flash->ctrl = espi_ctrl;
+
+ /* Bus lock */
+ mutex_init(&espi_flash->lock);
+
+ init_waitqueue_head(&espi_flash->wq);
+
+ spin_lock_init(&espi_flash->spinlock);
+
+ dma = &espi_flash->dma;
+
+ dma->tx_virt =
+ dma_alloc_coherent(dev, PAGE_SIZE, &dma->tx_addr, GFP_KERNEL);
+ if (!dma->tx_virt) {
+ dev_err(dev, "cannot allocate DMA TX buffer\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ dma->rx_virt =
+ dma_alloc_coherent(dev, PAGE_SIZE, &dma->rx_addr, GFP_KERNEL);
+ if (!dma->rx_virt) {
+ dev_err(dev, "cannot allocate DMA RX buffer\n");
+ return ERR_PTR(-ENOMEM);
+ }
+ index = of_property_match_string(dev->of_node, "reg-names",
+ "espi_flash");
+ ret = of_address_to_resource(dev->of_node, index, &res);
+ if (ret < 0) {
+ dev_err(dev, "something went wrong\n");
+ return ERR_PTR(-ENODEV);
+ }
+ reg = resource_size(&res);
+ mtd = &espi_flash->mtd;
+ mtd->dev.parent = dev;
+ mtd->size = reg;
+ mtd->flags = MTD_CAP_NORFLASH;
+ mtd->_erase = aspeed_espi_flash_erase;
+ mtd->_read = aspeed_espi_flash_read;
+ mtd->_write = aspeed_espi_flash_write;
+ mtd->type = MTD_NORFLASH;
+ mtd->name = DEVICE_NAME;
+
+ regmap_read(espi_ctrl->map, ESPI_CH3_CAP_N_CONF, &reg);
+ reg = (reg & ESPI_CH3_CAP_N_CONF_ERASE_MASK) >>
+ ESPI_CH3_CAP_N_CONF_ERASE_SHIFT;
+ espi_flash->erase_mask = reg;
+ switch (reg) {
+ case ESPI_CH3_CAP_N_CONF_ERASE_SIZE_4KB:
+ case ESPI_CH3_CAP_N_CONF_ERASE_SIZE_4KB_64KB:
+ mtd->erasesize = 0x1000;
+ espi_flash->erase_mask = 1;
+ break;
+ case ESPI_CH3_CAP_N_CONF_ERASE_SIZE_64KB:
+ mtd->erasesize = 0x10000;
+ break;
+ case ESPI_CH3_CAP_N_CONF_ERASE_SIZE_128KB:
+ mtd->erasesize = 0x20000;
+ break;
+ case ESPI_CH3_CAP_N_CONF_ERASE_SIZE_256KB:
+ mtd->erasesize = 0x40000;
+ break;
+ default:
+ dev_notice("Unknown erase size %x\n", reg);
+ return ERR_PTR(-ENODEV);
+ }
+
+ mtd->writesize = 1;
+ mtd->owner = THIS_MODULE;
+ mtd->priv = espi_flash;
+
+ ret = mtd_device_register(mtd, NULL, 0);
+ if (ret) {
+ dev_notice("aspeed-espi-mtd: Failed to register mtd device\n");
+ return ERR_PTR(ret);
+ }
+
+ aspeed_espi_flash_enable(espi_flash);
+ return espi_flash;
+}
+
+void aspeed_espi_flash_free(struct device *dev,
+ struct aspeed_espi_flash *espi_flash)
+{
+ struct aspeed_espi_flash_dma *dma = &espi_flash->dma;
+
+ dma_free_coherent(dev, PAGE_SIZE, dma->tx_virt, dma->tx_addr);
+ dma_free_coherent(dev, PAGE_SIZE, dma->rx_virt, dma->rx_addr);
+
+ mtd_device_unregister(&espi_flash->mtd);
+}
diff --git a/drivers/soc/aspeed/aspeed-espi-flash.h b/drivers/soc/aspeed/aspeed-espi-flash.h
new file mode 100644
index 000000000000..cceadd258c62
--- /dev/null
+++ b/drivers/soc/aspeed/aspeed-espi-flash.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2024 IBM Corporation.
+ */
+#ifndef _ASPEED_ESPI_FLASH_H_
+#define _ASPEED_ESPI_FLASH_H_
+
+#include <linux/mtd/mtd.h>
+
+enum aspeed_espi_flash_safs_mode {
+ SAFS_MODE_MIX,
+ SAFS_MODE_SW,
+ SAFS_MODE_HW,
+ SAFS_MODES,
+};
+
+struct aspeed_espi_flash_dma {
+ void *tx_virt;
+ dma_addr_t tx_addr;
+ void *rx_virt;
+ dma_addr_t rx_addr;
+};
+
+struct aspeed_espi_flash {
+
+ unsigned short page_offset; /* offset in flash address */
+ unsigned int page_size; /* of bytes per page */
+ struct mutex lock;
+ struct aspeed_espi_flash_dma dma;
+ struct mtd_info mtd;
+ struct aspeed_espi_ctrl *ctrl;
+ uint8_t erase_mask;
+ uint32_t tx_sts;
+ uint32_t rx_sts;
+ wait_queue_head_t wq;
+ spinlock_t spinlock;
+};
+
+void aspeed_espi_flash_event(uint32_t sts, struct aspeed_espi_flash *espi_flash);
+void aspeed_espi_flash_enable(struct aspeed_espi_flash *espi_flash);
+void *aspeed_espi_flash_alloc(struct device *dev, struct aspeed_espi_ctrl *espi_ctrl);
+void aspeed_espi_flash_free(struct device *dev, struct aspeed_espi_flash *espi_flash);
+
+#endif
+
diff --git a/include/uapi/linux/espi/aspeed-espi-ioc.h b/include/uapi/linux/espi/aspeed-espi-ioc.h
new file mode 100644
index 000000000000..fa5751fc7327
--- /dev/null
+++ b/include/uapi/linux/espi/aspeed-espi-ioc.h
@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2024 IBM Corporation.
+ */
+#ifndef _ASPEED_ESPI_IOC_H
+#define _ASPEED_ESPI_IOC_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/*
+ * eSPI cycle type encoding
+ *
+ * Section 5.1 Cycle Types and Packet Format,
+ * Intel eSPI Interface Base Specification, Rev 1.0, Jan. 2016.
+ */
+#define ESPI_FLASH_READ 0x00
+#define ESPI_FLASH_WRITE 0x01
+#define ESPI_FLASH_ERASE 0x02
+#define ESPI_FLASH_SUC_CMPLT 0x06
+#define ESPI_FLASH_SUC_CMPLT_D_MIDDLE 0x09
+#define ESPI_FLASH_SUC_CMPLT_D_FIRST 0x0b
+#define ESPI_FLASH_SUC_CMPLT_D_LAST 0x0d
+#define ESPI_FLASH_SUC_CMPLT_D_ONLY 0x0f
+#define ESPI_FLASH_UNSUC_CMPLT 0x0c
+#define ESPI_FLASH_UNSUC_CMPLT_ONLY 0x0e
+
+/*
+ * eSPI packet format structure
+ *
+ * Section 5.1 Cycle Types and Packet Format,
+ * Intel eSPI Interface Base Specification, Rev 1.0, Jan. 2016.
+ */
+struct espi_comm_hdr {
+ uint8_t cyc;
+ uint8_t len_h : 4;
+ uint8_t tag : 4;
+ uint8_t len_l;
+};
+
+struct espi_flash_rwe {
+ uint8_t cyc;
+ uint8_t len_h : 4;
+ uint8_t tag : 4;
+ uint8_t len_l;
+ uint32_t addr_be;
+ uint8_t data[];
+} __packed;
+
+struct espi_flash_cmplt {
+ uint8_t cyc;
+ uint8_t len_h : 4;
+ uint8_t tag : 4;
+ uint8_t len_l;
+ uint8_t data[];
+} __packed;
+
+struct aspeed_espi_ioc {
+ uint32_t pkt_len;
+ uint8_t *pkt;
+};
+
+/*
+ * we choose the longest header and the max payload size
+ * based on the Intel specification to define the maximum
+ * eSPI packet length
+ */
+#define ESPI_PLD_LEN_MIN (1UL << 6)
+#define ESPI_PLD_LEN_MAX (1UL << 12)
+#define ESPI_PKT_LEN_MAX (sizeof(struct espi_perif_msg) + ESPI_PLD_LEN_MAX)
+
+#define __ASPEED_ESPI_IOCTL_MAGIC 0xb8
+
+/*
+ * The IOCTL-based interface works in the eSPI packet in/out paradigm.
+ *
+ * Only the virtual wire IOCTL is a special case which does not send
+ * or receive an eSPI packet. However, to keep a more consistent use from
+ * userspace, we make all of the four channel drivers serve through the
+ * IOCTL interface.
+ *
+ * For the eSPI packet format, refer to
+ * Section 5.1 Cycle Types and Packet Format,
+ * Intel eSPI Interface Base Specification, Rev 1.0, Jan. 2016.
+ *
+ * For the example user apps using these IOCTL, refer to
+ * https://github.com/AspeedTech-BMC/aspeed_app/tree/master/espi_test
+ */
+
+/*
+ * Flash Channel (CH3)
+ * - ASPEED_ESPI_FLASH_GET_RX
+ * Receive an eSPI flash packet
+ * - ASPEED_ESPI_FLASH_PUT_TX
+ * Transmit an eSPI flash packet
+ */
+#define ASPEED_ESPI_FLASH_GET_RX _IOR(__ASPEED_ESPI_IOCTL_MAGIC, \
+ 0x30, struct aspeed_espi_ioc)
+#define ASPEED_ESPI_FLASH_PUT_TX _IOW(__ASPEED_ESPI_IOCTL_MAGIC, \
+ 0x31, struct aspeed_espi_ioc)
+
+#endif
+

---
base-commit: 841c35169323cd833294798e58b9bf63fa4fa1de
change-id: 20240213-espi_driver-5861a64d7dc4

Best regards,
--
Manojkiran Eda <manojkiran.eda@xxxxxxxxx>