Add iop driver for Sunplus SP7021

Add iop yaml file for Sunplus SP7021

Signed-off-by Tony Huang <[email protected]>

---
Changes in v4:
- Addressed comments from Rob Herring.

 .../devicetree/bindings/misc/sunplus-iop.yaml      | 65 ++++++++++++++++++++++
 MAINTAINERS                                        |  5 ++
 2 files changed, 70 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/misc/sunplus-iop.yaml

IOP (IO Processor) embedded inside SP7021 which is used as Processor for I/O control, RTC wake-up and cooperation with CPU & PMC in power management purpose.
The IOP core is DQ8051, so also named IOP8051,
it supports dedicated JTAG debug pins which share with SP7021. In standby mode operation, the power spec reach 400uA.

Signed-off-by Tony Huang <[email protected]>

---
Changes in v4:
- Addressed comments from Arnd Bergmann.
- Addressed comments from Greg KH.

 Documentation/ABI/testing/sysfs-platform-soc@B |  22 ++
 MAINTAINERS                                    |   2 +
 drivers/misc/Kconfig                           |  12 +
 drivers/misc/Makefile                          |   1 +
 drivers/misc/sunplus_iop.c                     | 496 +++++++++++++++++++++++++
 5 files changed, 533 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-platform-soc@B
 create mode 100644 drivers/misc/sunplus_iop.c

Documentation/ABI/testing/sysfs-platform-soc@B new file +22 -0

new file mode 100644
index 0000000..17d838e
@@ -0,0 +1,22 @@
+What:		/sys/devices/platform/soc@B/9c000400.iop/sp_iop_state1
+Date:		December 2021
+KernelVersion:	5.15
+Contact:	Tony Huang <[email protected]>
+Description:
+		SP7021 has three power states:S0, S1 and S3.
+		S0:Default domain is on. IOP domain is on. AO domain is on.
+		S1:Default domain is off. IOP domain is on. AO domain is on.
+		S3:Default domain is off. IOP domain is off. AO domain is on.
+		Read sysfs sp_iop_s1mode, system enter S1 mode.
+
+What:		/sys/devices/platform/soc@B/9c000400.iop/sp_iop_mode
+Date:		December 2021
+KernelVersion:	5.15
+Contact:	Tony Huang <[email protected]>
+Description:
+		Operation mode of IOP is switched to standby mode by writing
+		"1" to sysfs.
+		Operation mode of IOP is switched to normal mode by writing
+		"0" to sysfs.
+
+

MAINTAINERS +2 -0

index 071b5e6..614b7ff 100644
@@ -17948,7 +17948,9 @@ F:	drivers/net/ethernet/dlink/sundance.c
 SUNPLUS IOP DRIVER
 M:	Tony Huang <[email protected]>
 S:	Maintained
+F:	Documentation/ABI/testing/sysfs-platform-soc@B
 F:	Documentation/devicetree/bindings/misc/sunplu-iop.yaml
+F:	drivers/misc/sunplus_iop.c
 
 SUPERH
 M:	Yoshinori Sato <[email protected]>

drivers/misc/Kconfig +12 -0

index 0f5a49f..f19533b 100644
@@ -470,6 +470,18 @@ config HISI_HIKEY_USB
 	  switching between the dual-role USB-C port and the USB-A host ports
 	  using only one USB controller.
 
+config SUNPLUS_IOP
+	tristate "Sunplus IOP support"
+	default ARCH_SUNPLUS
+	help
+	  Sunplus I/O processor (8051) driver.
+	  Processor for I/O control, RTC wake-up proceduce management,
+	  and cooperation with CPU&PMC in power management.
+	  Need Install DQ8051, The DQ8051 bin file generated by keil C.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called ad525x_dpot.
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"

drivers/misc/Makefile +1 -0

index a086197..eafeab6 100644
@@ -52,6 +52,7 @@ obj-$(CONFIG_DW_XDATA_PCIE)	+= dw-xdata-pcie.o
 obj-$(CONFIG_PCI_ENDPOINT_TEST)	+= pci_endpoint_test.o
 obj-$(CONFIG_OCXL)		+= ocxl/
 obj-$(CONFIG_BCM_VK)		+= bcm-vk/
+obj-$(CONFIG_SUNPLUS_IOP)	+= sunplus_iop.o
 obj-y				+= cardreader/
 obj-$(CONFIG_PVPANIC)   	+= pvpanic/
 obj-$(CONFIG_HABANA_AI)		+= habanalabs/

drivers/misc/sunplus_iop.c new file +273 -0

new file mode 100644
index 0000000..8c4c870
@@ -0,0 +1,496 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * The IOP driver for Sunplus SP7021
+ *
+ * Copyright (C) 2021 Sunplus Technology Inc.
+ *
+ * All Rights Reserved.
+ */
+
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/of_platform.h>
+#include <linux/firmware.h>
+#include <linux/dma-mapping.h>
+#include <linux/of_address.h>
+#include <linux/delay.h>
+#include <linux/iopoll.h>
+
+enum IOP_Status_e {
+	IOP_SUCCESS,                /* successful */
+	IOP_ERR_IOP_BUSY,           /* IOP is busy */
+};
+
+struct regs_moon0 {
+	u32 stamp;         /* 00 */
+	u32 clken[10];     /* 01~10 */
+	u32 gclken[10];    /* 11~20 */
+	u32 reset[10];     /* 21~30 */
+	u32 sfg_cfg_mode;  /* 31 */
+};
+
+struct regs_iop {
+	u32 iop_control;/* 00 */
+	u32 iop_reg1;/* 01 */
+	u32 iop_bp;/* 02 */
+	u32 iop_regsel;/* 03 */
+	u32 iop_regout;/* 04 */
+	u32 iop_reg5;/* 05 */
+	u32 iop_resume_pcl;/* 06 */
+	u32 iop_resume_pch;/* 07 */
+	u32 iop_data0;/* 08 */
+	u32 iop_data1;/* 09 */
+	u32 iop_data2;/* 10 */
+	u32 iop_data3;/* 11 */
+	u32 iop_data4;/* 12 */
+	u32 iop_data5;/* 13 */
+	u32 iop_data6;/* 14 */
+	u32 iop_data7;/* 15 */
+	u32 iop_data8;/* 16 */
+	u32 iop_data9;/* 17 */
+	u32 iop_data10;/* 18 */
+	u32 iop_data11;/* 19 */
+	u32 iop_base_adr_l;/* 20 */
+	u32 iop_base_adr_h;/* 21 */
+	u32 memory_bridge_control;/* 22 */
+	u32 iop_regmap_adr_l;/* 23 */
+	u32 iop_regmap_adr_h;/* 24 */
+	u32 iop_direct_adr;/* 25*/
+	u32 reserved[6];/* 26~31 */
+};
+
+struct regs_iop_pmc {
+	u32 PMC_TIMER;/* 00 */
+	u32 PMC_CTRL;/* 01 */
+	u32 XTAL27M_PASSWORD_I;/* 02 */
+	u32 XTAL27M_PASSWORD_II;/* 03 */
+	u32 XTAL32K_PASSWORD_I;/* 04 */
+	u32 XTAL32K_PASSWORD_II;/* 05 */
+	u32 CLK27M_PASSWORD_I;/* 06 */
+	u32 CLK27M_PASSWORD_II;/* 07 */
+	u32 PMC_TIMER2;/* 08 */
+	u32 reserved[23];/* 9~31 */
+};
+
+#define NORMAL_CODE_MAX_SIZE 0X1000
+#define STANDBY_CODE_MAX_SIZE 0x4000
+struct sp_iop {
+	struct miscdevice dev;			// iop device
+	struct mutex write_lock;
+	void __iomem *iop_regs;
+	void __iomem *pmc_regs;
+	void __iomem *moon0_regs;
+	int irq;
+	unsigned char iop_normal_code[NORMAL_CODE_MAX_SIZE];
+	unsigned char iop_standby_code[STANDBY_CODE_MAX_SIZE];
+	resource_size_t iop_mem_start;
+	resource_size_t iop_mem_size;
+	bool mode;
+};
+
+static void sp_iop_normal_mode(struct sp_iop *iop)
+{
+	struct regs_iop *p_iop_reg = (struct regs_iop *)iop->iop_regs;
+	struct regs_moon0 *p_moon0_reg = (struct regs_moon0 *)iop->moon0_regs;
+	void __iomem *iop_kernel_base;
+	unsigned int reg;
+
+	iop_kernel_base = ioremap(iop->iop_mem_start, NORMAL_CODE_MAX_SIZE);
+	memset(iop_kernel_base, 0, NORMAL_CODE_MAX_SIZE);
+	memcpy(iop_kernel_base, iop->iop_normal_code, NORMAL_CODE_MAX_SIZE);
+
+	writel(0x00100010, &p_moon0_reg->clken[0]);
+
+	reg = readl(&p_iop_reg->iop_control);
+	reg |= 0x01;
+	writel(reg, &p_iop_reg->iop_control);
+
+	reg = readl(&p_iop_reg->iop_control);
+	reg &= ~(0x8000);
+	writel(reg, &p_iop_reg->iop_control);
+
+	reg = readl(&p_iop_reg->iop_control);
+	reg |= 0x0200;//disable watchdog event reset IOP
+	writel(reg, &p_iop_reg->iop_control);
+
+	reg = (iop->iop_mem_start & 0xFFFF);
+	writel(reg, &p_iop_reg->iop_base_adr_l);
+	reg	= (iop->iop_mem_start >> 16);
+	writel(reg, &p_iop_reg->iop_base_adr_h);
+
+	reg = readl(&p_iop_reg->iop_control);
+	reg &= ~(0x01);
+	writel(reg, &p_iop_reg->iop_control);
+	iop->mode = 0;
+}
+
+static void sp_iop_standby_mode(struct sp_iop *iop)
+{
+	struct regs_iop *p_iop_reg = (struct regs_iop *)iop->iop_regs;
+	struct regs_moon0 *p_moon0_reg = (struct regs_moon0 *)iop->moon0_regs;
+	void __iomem *iop_kernel_base;
+	unsigned long reg;
+
+	iop_kernel_base = ioremap(iop->iop_mem_start, STANDBY_CODE_MAX_SIZE);
+	memset(iop_kernel_base, 0, STANDBY_CODE_MAX_SIZE);
+	memcpy(iop_kernel_base, iop->iop_standby_code, STANDBY_CODE_MAX_SIZE);
+
+	writel(0x00100010, &p_moon0_reg->clken[0]);
+
+	reg = readl(&p_iop_reg->iop_control);
+	reg |= 0x01;
+	writel(reg, &p_iop_reg->iop_control);
+
+	reg = readl(&p_iop_reg->iop_control);
+	reg &= ~(0x8000);
+	writel(reg, &p_iop_reg->iop_control);
+
+	reg = readl(&p_iop_reg->iop_control);
+	reg |= 0x0200;//disable watchdog event reset IOP
+	writel(reg, &p_iop_reg->iop_control);
+
+	reg = (iop->iop_mem_start & 0xFFFF);
+	writel(reg, &p_iop_reg->iop_base_adr_l);
+	reg = (iop->iop_mem_start >> 16);
+	writel(reg, &p_iop_reg->iop_base_adr_h);
+
+	reg = readl(&p_iop_reg->iop_control);
+	reg &= ~(0x01);
+	writel(reg, &p_iop_reg->iop_control);
+	iop->mode = 1;
+}
+
+#define IOP_READY	0x4
+#define RISC_READY	0x8
+static int sp_iop_shutdown(struct device *dev, struct sp_iop *iop)
+{
+	struct regs_iop *p_iop_reg = (struct regs_iop *)iop->iop_regs;
+	struct regs_moon0 *p_moon0_reg = (struct regs_moon0 *)iop->moon0_regs;
+	struct regs_iop_pmc *p_iop_pmc_reg = (struct regs_iop_pmc *)iop->pmc_regs;
+	unsigned int reg;
+	int ret, value;
+
+	writel(0x00100010, &p_moon0_reg->clken[0]);
+
+	reg = readl(&p_iop_reg->iop_control);
+	reg &= ~(0x8000);
+	writel(reg, &p_iop_reg->iop_control);
+
+	reg = readl(&p_iop_reg->iop_control);
+	reg |= 0x1;
+	writel(reg, &p_iop_reg->iop_control);
+
+	//PMC set
+	writel(0x00010001, &p_iop_pmc_reg->PMC_TIMER);
+	reg = readl(&p_iop_pmc_reg->PMC_CTRL);
+	reg |= 0x23;// disable system reset PMC, enalbe power down 27M, enable gating 27M
+	writel(reg, &p_iop_pmc_reg->PMC_CTRL);
+
+	writel(0x55aa00ff, &p_iop_pmc_reg->XTAL27M_PASSWORD_I);
+	writel(0x00ff55aa, &p_iop_pmc_reg->XTAL27M_PASSWORD_II);
+	writel(0xaa00ff55, &p_iop_pmc_reg->XTAL32K_PASSWORD_I);
+	writel(0xff55aa00, &p_iop_pmc_reg->XTAL32K_PASSWORD_II);
+	writel(0xaaff0055, &p_iop_pmc_reg->CLK27M_PASSWORD_I);
+	writel(0x5500aaff, &p_iop_pmc_reg->CLK27M_PASSWORD_II);
+	writel(0x01000100, &p_iop_pmc_reg->PMC_TIMER2);
+
+	//IOP Hardware IP reset
+	reg = readl(&p_moon0_reg->reset[0]);
+	reg |= 0x10;
+	writel(reg, (&p_moon0_reg->reset[0]));
+	reg &= ~(0x10);
+	writel(reg, (&p_moon0_reg->reset[0]));
+
+	writel(0x00ff0085, (iop->moon0_regs + 32 * 4 * 1 + 4 * 1));
+
+	reg = readl(iop->moon0_regs + 32 * 4 * 1 + 4 * 2);
+	reg |= 0x08000800;
+	writel(reg, (iop->moon0_regs + 32 * 4 * 1 + 4 * 2));
+
+	reg = readl(&p_iop_reg->iop_control);
+	reg |= 0x0200;//disable watchdog event reset IOP
+	writel(reg, &p_iop_reg->iop_control);
+
+	reg = (iop->iop_mem_start & 0xFFFF);
+	writel(reg, &p_iop_reg->iop_base_adr_l);
+	reg = (iop->iop_mem_start >> 16);
+	writel(reg, &p_iop_reg->iop_base_adr_h);
+
+	reg = readl(&p_iop_reg->iop_control);
+	reg &= ~(0x01);
+	writel(reg, &p_iop_reg->iop_control);
+
+	ret = readl_poll_timeout(&p_iop_reg->iop_data2, value,
+				 (value & IOP_READY) == IOP_READY, 1000, 10000);
+	if (ret) {
+		dev_err(dev, "timed out\n");
+		return ret;
+	}
+
+	writel(RISC_READY, &p_iop_reg->iop_data2);
+	writel(0x00, &p_iop_reg->iop_data5);
+	writel(0x60, &p_iop_reg->iop_data6);
+
+	ret = readl_poll_timeout(&p_iop_reg->iop_data7, value,
+				 value == 0xaaaa, 1000, 10000);
+	if (ret) {
+		dev_err(dev, "timed out\n");
+		return ret;
+	}
+
+	writel(0xdd, &p_iop_reg->iop_data1);//8051 bin file call Ultra low function.
+	mdelay(10);
+	return 0;
+}
+
+static int sp_iop_s1mode(struct device *dev, struct sp_iop *iop)
+{
+	struct regs_iop *p_iop_reg = (struct regs_iop *)iop->iop_regs;
+	int ret, value;
+
+	ret = readl_poll_timeout(&p_iop_reg->iop_data2, value,
+				 (value & IOP_READY) == IOP_READY, 1000, 10000);
+	if (ret) {
+		dev_err(dev, "timed out\n");
+		return ret;
+	}
+
+	writel(RISC_READY, &p_iop_reg->iop_data2);
+	writel(0x00, &p_iop_reg->iop_data5);
+	writel(0x60, &p_iop_reg->iop_data6);
+
+	ret = readl_poll_timeout(&p_iop_reg->iop_data7, value,
+				 value == 0xaaaa, 1000, 10000);
+	if (ret) {
+		dev_err(dev, "timed out\n");
+		return ret;
+	}
+
+	writel(0xee, &p_iop_reg->iop_data1);//8051 bin file call S1_mode function.
+	mdelay(10);
+	return 0;
+}
+

drivers/misc/sunplus_iop.c new file +9 -0

+static ssize_t sp_iop_mode_store(struct device *dev, struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	struct sp_iop *iop = dev_get_drvdata(dev);
+	unsigned char ret = count;
+
+	if (buf[0] == '0') {
+		sp_iop_normal_mode(iop);
+		dev_info(dev, "Switch to normal mode.\n");

drivers/misc/sunplus_iop.c new file +80 -0

+static int  sp_iop_get_normal_code(struct device *dev, struct sp_iop *iop)
+{
+	const struct firmware *fw;
+	static const char file[] = "normal.bin";
+	unsigned int err, i;
+
+	err = request_firmware(&fw, file, dev);
+	if (err) {
+		dev_err(dev, "get bin file error\n");
+		return err;
+	}
+
+	for (i = 0; i < NORMAL_CODE_MAX_SIZE; i++) {
+		char temp;
+
+		temp = fw->data[i];
+		iop->iop_normal_code[i] = temp;
+	}
+	release_firmware(fw);
+	return err;
+}
+
+static int  sp_iop_get_standby_code(struct device *dev, struct sp_iop *iop)
+{
+	const struct firmware *fw;
+	static const char file[] = "standby.bin";
+	unsigned int err, i;
+
+	err = request_firmware(&fw, file, dev);
+	if (err) {
+		dev_err(dev, "get bin file error\n");
+		return err;
+	}
+
+	for (i = 0; i < STANDBY_CODE_MAX_SIZE; i++) {
+		char temp;
+
+		temp = fw->data[i];
+		iop->iop_standby_code[i] = temp;
+	}
+	release_firmware(fw);
+	return err;
+}
+
+static int sp_iop_get_resources(struct platform_device *pdev, struct sp_iop *p_sp_iop_info)
+{
+	struct resource *r;
+
+	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "iop");
+	p_sp_iop_info->iop_regs = devm_ioremap_resource(&pdev->dev, r);
+	if (IS_ERR(p_sp_iop_info->iop_regs)) {
+		dev_err(&pdev->dev, "ioremap fail\n");
+		return PTR_ERR(p_sp_iop_info->iop_regs);
+	}
+
+	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "iop_pmc");
+	p_sp_iop_info->pmc_regs = devm_ioremap_resource(&pdev->dev, r);
+	if (IS_ERR(p_sp_iop_info->pmc_regs)) {
+		dev_err(&pdev->dev, "ioremap fail\n");
+		return PTR_ERR(p_sp_iop_info->pmc_regs);
+	}
+
+	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "moon0");
+	p_sp_iop_info->moon0_regs = devm_ioremap_resource(&pdev->dev, r);
+	if (IS_ERR(p_sp_iop_info->moon0_regs)) {
+		dev_err(&pdev->dev, "ioremap fail\n");
+		return PTR_ERR(p_sp_iop_info->moon0_regs);
+	}
+	return IOP_SUCCESS;
+}
+
+static int sp_iop_platform_driver_probe(struct platform_device *pdev)
+{
+	int ret = -ENXIO;
+	int rc;
+	struct sp_iop *iop;
+	struct device_node *memnp;
+	struct resource mem_res;
+
+	iop = devm_kzalloc(&pdev->dev, sizeof(struct sp_iop), GFP_KERNEL);

Quoted 5 lines

drivers/misc/sunplus_iop.c new file +5 -0

+
+static ssize_t sp_iop_state1_show(struct device *dev, struct
+device_attribute *attr, char *buf) {
+     struct sp_iop *iop = dev_get_drvdata(dev);
+     ssize_t len = 0;

drivers/misc/sunplus_iop.c line 283

Quoted 6 lines

drivers/misc/sunplus_iop.c new file +6 -0

+
+     sp_iop_standby_mode(iop);
+     mdelay(10);
+     sp_iop_s1mode(dev, iop);
+     return len;
+}

This function is not showing anything.

Review

Quoted 2 lines

(quoted diff) +2 -0

+
+static ssize_t sp_iop_state1_store(struct device *dev, struct

device_attribute *attr,

drivers/misc/sunplus_iop.c line 283

Quoted 5 lines

drivers/misc/sunplus_iop.c new file +5 -0

+                                const char *buf, size_t count) {
+     ssize_t len = 0;
+
+     return len;
+}

Why do you have an empty store function?

drivers/misc/sunplus_iop.c line 303

Quoted 12 lines

drivers/misc/sunplus_iop.c new file +12 -0

+
+static ssize_t sp_iop_mode_show(struct device *dev, struct
+device_attribute *attr, char *buf) {
+     struct sp_iop *iop = dev_get_drvdata(dev);
+     ssize_t len = 0;
+
+     if (iop->mode == 0)
+             dev_info(dev, "iop_normal_mode\n");
+     else if (iop->mode == 1)
+             dev_info(dev, "iop_standby_mode\n");
+     return len;
+}

Again, this is not returning anything in sysfs.

How was this tested???

Quoted 1 line

+static ssize_t sp_iop_mode_store(struct device *dev, struct device_attribute

*attr,

Quoted 7 lines

drivers/misc/sunplus_iop.c new file +7 -0

+                              const char *buf, size_t count) {
+     struct sp_iop *iop = dev_get_drvdata(dev);
+     unsigned char ret = count;
+
+     if (buf[0] == '0') {
+             sp_iop_normal_mode(iop);
+             dev_info(dev, "Switch to normal mode.\n");

drivers/misc/sunplus_iop.c line 323

Quoted 10 lines

drivers/misc/sunplus_iop.c new file +10 -0

+     } else if (buf[0] == '1') {
+             sp_iop_standby_mode(iop);
+             dev_info(dev, "Switch to standby mode.\n");
+     } else {
+             dev_info(dev, "echo 0 or 1 mode\n");
+             dev_info(dev, "0:normal mode\n");
+             dev_info(dev, "1:standby mode\n");
+     }
+     return ret;
+}

dev_info() is NOT for stuff like this at all. You do not display a "help" file or anything else like that in this way.

Please use sysfs correctly.

Also, there is a function to read 1/0 from sysfs, please use that.

Dear Gregkh:

Quoted 5 lines

Quoted 5 lines

drivers/misc/sunplus_iop.c new file +5 -0

+
+static ssize_t sp_iop_state1_show(struct device *dev, struct
+device_attribute *attr, char *buf) {
+     struct sp_iop *iop = dev_get_drvdata(dev);
+     ssize_t len = 0;

Quoted 9 lines

drivers/misc/sunplus_iop.c line 283

Quoted 6 lines

drivers/misc/sunplus_iop.c new file +6 -0

+
+     sp_iop_standby_mode(iop);
+     mdelay(10);
+     sp_iop_s1mode(dev, iop);
+     return len;
+}

This function is not showing anything.

The purpose of this function:
SP7021 has three power states:S0, S1 and S3. S0:Default domain is on. IOP domain is on. AO domain is on. S1:Default domain is off. IOP domain is on. AO domain is on. S3:Default domain is off. IOP domain is off. AO domain is on. System enter S1 mode when read sysfs sp_iop_state1,

I hope to provide users with the ability to enter S1 mode by themselves. So I cannot use DEVICE_ATTR. I should use file_operations method.

Quoted 18 lines

Quoted 5 lines

Quoted 5 lines

drivers/misc/sunplus_iop.c new file +5 -0

+
+static ssize_t sp_iop_state1_show(struct device *dev, struct
+device_attribute *attr, char *buf) {
+     struct sp_iop *iop = dev_get_drvdata(dev);
+     ssize_t len = 0;

Quoted 9 lines

drivers/misc/sunplus_iop.c line 283

Quoted 6 lines

drivers/misc/sunplus_iop.c new file +6 -0

+
+     sp_iop_standby_mode(iop);
+     mdelay(10);
+     sp_iop_s1mode(dev, iop);
+     return len;
+}

This function is not showing anything.

The purpose of this function:
SP7021 has three power states:S0, S1 and S3. S0:Default domain is on. IOP domain is on. AO domain is on.

Quoted 5 lines

S1:Default domain is off. IOP domain is on. AO domain is on.

S3:Default domain is off. IOP domain is off. AO domain is on.

System enter S1 mode when read sysfs sp_iop_state1,

That is not what sysfs is for, sorry.

Quoted 4 lines

I hope to provide users with the ability to enter S1 mode by themselves.

So I cannot use DEVICE_ATTR. I should use file_operations method.

No, please use the normal power management callbacks for your driver that all other drivers use in the kernel. There is nothing special about this one driver to warrant a totally new user/kernel api for it.

IOP (IO Processor) embedded inside SP7021 which is used as Processor for I/O control, RTC wake-up and cooperation with CPU & PMC in power management purpose.
The IOP core is DQ8051, so also named IOP8051,
it supports dedicated JTAG debug pins which share with SP7021. In standby mode operation, the power spec reach 400uA.

Signed-off-by Tony Huang <[email protected]>

---
Changes in v4:
- Addressed comments from Arnd Bergmann.

Dear Arnd:

Quoted 13 lines · On Thu, Dec 16, 2021 at 2:38 AM Tony Huang…

Quoted 8 lines

IOP (IO Processor) embedded inside SP7021 which is used as Processor for I/O control, RTC wake-up and cooperation with CPU & PMC in power management purpose.
The IOP core is DQ8051, so also named IOP8051,
it supports dedicated JTAG debug pins which share with SP7021. In standby mode operation, the power spec reach 400uA.

Quoted 4 lines

Signed-off-by Tony Huang <[email protected]<mailto:[email protected]>>

---
Changes in v4:
- Addressed comments from Arnd Bergmann.

Quoted 5 lines

I don't think you did: I asked you specifically to add code to interact with the existing in-kernel interfaces to use the functionality provided by the device. Pick any (at least two) subsystems and add support, but leave out any custom user space interfaces (miscdevice, debugfs, sysfs, ...) for the moment.

1. IOP can run sp_iop_platform_driver_shudown() through the poweroff command and the kernel. Perform system power-off actions.
2. Wake up the system by relying on the 8051 internal RTC wake-up mechanism and external GPIO input signals to wake up. 3.So you ask me to control IOP(8051) through file_operations, not through DEVICE_ATTR

Dear Arnd:

Quoted 13 lines · Tony Huang

Quoted 8 lines

IOP (IO Processor) embedded inside SP7021 which is used as Processor for I/O control, RTC wake-up and cooperation with CPU & PMC in power management purpose.
The IOP core is DQ8051, so also named IOP8051,
it supports dedicated JTAG debug pins which share with SP7021. In standby mode operation, the power spec reach 400uA.

Quoted 4 lines

Signed-off-by Tony Huang <[email protected]>

---
Changes in v4:
- Addressed comments from Arnd Bergmann.

Quoted 5 lines

I don't think you did: I asked you specifically to add code to interact with the existing in-kernel interfaces to use the functionality provided by the device. Pick any (at least two) subsystems and add support, but leave out any custom user space interfaces (miscdevice, debugfs, sysfs, ...) for the moment.

1. IOP can run sp_iop_platform_driver_shudown() through the poweroff command and the kernel. Perform system power-off actions.

2. Wake up the system by relying on the 8051 internal RTC wake-up mechanism and external GPIO input signals to wake up.

3.So you ask me to control IOP(8051) through file_operations, not through DEVICE_ATTR

Quoted 21 lines

Quoted 13 lines

Quoted 8 lines

IOP (IO Processor) embedded inside SP7021 which is used as Processor for I/O control, RTC wake-up and cooperation with CPU & PMC in power management purpose.
The IOP core is DQ8051, so also named IOP8051, it supports dedicated JTAG debug pins which share with SP7021.
In standby mode operation, the power spec reach 400uA.

Quoted 4 lines

Signed-off-by Tony Huang <[email protected]>

---
Changes in v4:
- Addressed comments from Arnd Bergmann.

Quoted 5 lines

I don't think you did: I asked you specifically to add code to interact with the existing in-kernel interfaces to use the functionality provided by the device. Pick any (at least two) subsystems and add support, but leave out any custom user space interfaces (miscdevice, debugfs, sysfs, ...) for the moment.

Quoted 2 lines

1. IOP can run sp_iop_platform_driver_shudown() through the poweroff command and the kernel. Perform system power-off actions.

Do you mean that this method a) cleanly shuts down the iop before the system is powered down, or b) the driver_shutdown() callback is used to initiate the powerdown of the system itself?

In case of a) I would not count that as exposing functionality, what you do here is just part of any driver. If instead you are trying to use b), this is the wrong way of doing it, see drivers/power/reset/ for examples of how to do it right.

Quoted 2 lines

2. Wake up the system by relying on the 8051 internal RTC wake-up mechanism and external GPIO input signals to wake up.

I think those should be exposed with drivers/rtc for the RTC and drivers/gpio/ for the GPIO driver, and then you can use the device tree to configure which GPIO to use as a wakeup and how it's connected to the RTC.

Quoted 2 lines

3.So you ask me to control IOP(8051) through file_operations, not through DEVICE_ATTR

No, neither of them. Use the appropriate drivers/*/ subsystems for any functionality that has an existing subsystem. If there is something that the iop does that does not yet have a subsystem, that requires a more thorough design discussion for creating a new user interface, ideally in a hardware-independent way. You should not start with that until all the normal features (rtc, wakeup, suspend, gpio, ...) are supported.

Arnd

Quoted 3 lines

3.So you ask me to control IOP(8051) through file_operations, not through DEVICE_ATTR

No, neither of them. Use the appropriate drivers/*/ subsystems for any functionality that has an existing subsystem. If there is something that the iop does that does not yet have a subsystem, that requires a more thorough design discussion for creating a new user interface, ideally in a hardware-independent way. You should not start with that until all the normal features (rtc, wakeup, suspend, gpio, ...) are supported.

Quoted 20 lines

Quoted 12 lines

Quoted 11 lines

IOP (IO Processor) embedded inside SP7021 which is used as Processor for I/O control, RTC wake-up and cooperation with CPU & PMC in power management purpose.
The IOP core is DQ8051, so also named IOP8051, it supports dedicated JTAG debug pins which share with SP7021.
In standby mode operation, the power spec reach 400uA.

Signed-off-by Tony Huang <[email protected]>

---
Changes in v4:
- Addressed comments from Arnd Bergmann.

Quoted 5 lines

I don't think you did: I asked you specifically to add code to interact with the existing in-kernel interfaces to use the functionality provided by the device. Pick any (at least two) subsystems and add support, but leave out any custom user space interfaces (miscdevice, debugfs, sysfs, ...) for the moment.

Quoted 2 lines

1. IOP can run sp_iop_platform_driver_shudown() through the poweroff command and the kernel. Perform system power-off actions.

Do you mean that this method a) cleanly shuts down the iop before the system is powered down, or b) the driver_shutdown() callback is used to initiate the powerdown of the system itself?

In case of a) I would not count that as exposing functionality, what you do here is just part of any driver. If instead you are trying to use b), this is the wrong way of doing it, see drivers/power/reset/ for examples of how to do it right.

Quoted 2 lines

2. Wake up the system by relying on the 8051 internal RTC wake-up mechanism and external GPIO input signals to wake up.

I think those should be exposed with drivers/rtc for the RTC and drivers/gpio/ for the GPIO driver, and then you can use the device tree to configure which GPIO to use as a wakeup and how it's connected to the RTC.