[PATCH v10 0/2] Add iop driver for Sunplus SP7021

[PATCH v10 0/2] Add iop driver for Sunplus SP7021

[Tony Huang]

Add iop driver for Sunplus SP7021 SOC

This is a patch series for iop driver for Sunplus SP7021 SOC.

Sunplus SP7021 is an ARM Cortex A7 (4 cores) based SoC. It integrates
many peripherals (ex: UART, I2C, SPI, SDIO, eMMC, USB, SD card and
etc.) into a single chip. It is designed for industrial control.

Refer to:
https://sunplus-tibbo.atlassian.net/wiki/spaces/doc/overview
https://tibbo.com/store/plus1.html

Tony Huang (2):
  dt-binding: misc: Add iop yaml file for Sunplus SP7021
  misc: Add iop driver for Sunplus SP7021

 .../devicetree/bindings/misc/sunplus-iop.yaml      |  76 ++++
 MAINTAINERS                                        |   6 +
 drivers/misc/Kconfig                               |  36 ++
 drivers/misc/Makefile                              |   1 +
 drivers/misc/sunplus_iop.c                         | 438 +++++++++++++++++++++
 5 files changed, 557 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/misc/sunplus-iop.yaml
 create mode 100644 drivers/misc/sunplus_iop.c

-- 
2.7.4

[PATCH v10 1/2] dt-binding: misc: Add iop yaml file for Sunplus SP7021

[Tony Huang]

Add iop yaml file for Sunplus SP7021

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Huang <tonyhuang.sunplus@gmail.com>
---
Changes in v10:
 -No change

 .../devicetree/bindings/misc/sunplus-iop.yaml      | 76 ++++++++++++++++++++++
 MAINTAINERS                                        |  5 ++
 2 files changed, 81 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/misc/sunplus-iop.yaml

diff --git a/Documentation/devicetree/bindings/misc/sunplus-iop.yaml b/Documentation/devicetree/bindings/misc/sunplus-iop.yaml
new file mode 100644
index 0000000..b37e697
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/sunplus-iop.yaml
@@ -0,0 +1,76 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) Sunplus Ltd. Co. 2021
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/misc/sunplus-iop.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sunplus IOP(8051) controller
+
+maintainers:
+  - Tony Huang <tonyhuang.sunplus@gmail.com>
+
+description: |
+  Processor for I/O control, RTC wake-up procedure management,
+  and cooperation with CPU&PMC in power management.
+
+properties:
+  compatible:
+    enum:
+      - sunplus,sp7021-iop
+
+  reg:
+    items:
+      - description: IOP registers regions
+      - description: PMC registers regions
+      - description: MOON0 registers regions
+
+  reg-names:
+    items:
+      - const: iop
+      - const: iop_pmc
+      - const: moon0
+
+  interrupts:
+    items:
+      - description: IOP_INT0. IOP to system Interrupt 0.
+                     Sent by IOP to system RISC.
+      - description: IOP_INT1. IOP to System Interrupt 1.
+                     Sent by IOP to system RISC.
+
+  memory-region:
+    maxItems: 1
+
+  wakeup-gpios:
+    description: When the linux kernel system is powered off.
+      8051 is always powered. 8051 cand receive external signals
+      according to this gpio pin. 8051 receives external signal
+      through gpio pin. 8051 can power on linux kernel system.
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - interrupts
+  - memory-region
+  - wakeup-gpios
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/gpio/gpio.h>
+    iop: iop@9c000400 {
+        compatible = "sunplus,sp7021-iop";
+        reg = <0x9c000400 0x80>, <0x9c003100 0x80>, <0x9c000000 0x80>;
+        reg-names = "iop", "iop_pmc", "moon0";
+        interrupt-parent = <&intc>;
+        interrupts = <41 IRQ_TYPE_LEVEL_HIGH>, <42 IRQ_TYPE_LEVEL_HIGH>;
+        memory-region = <&iop_reserve>;
+        pinctrl-names = "default";
+        pinctrl-0 = <&iop_pins>;
+        wakeup-gpios = <&pctl 1 GPIO_ACTIVE_HIGH>;
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index fb18ce7..6f336c9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18242,6 +18242,11 @@ L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/net/ethernet/dlink/sundance.c
 
+SUNPLUS IOP DRIVER
+M:	Tony Huang <tonyhuang.sunplus@gmail.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/misc/sunplu-iop.yaml
+
 SUPERH
 M:	Yoshinori Sato <ysato@users.sourceforge.jp>
 M:	Rich Felker <dalias@libc.org>
-- 
2.7.4

[PATCH v10 2/2] misc: Add iop driver for Sunplus SP7021

[Tony Huang]

This driver is load 8051 bin code.
Processor for I/O control:
SP7021 has its own GPIO device driver.
The user can configure the gpio pin for 8051 use.
The 8051 support wake-up with IR key after system poweroff.

Monitor RTC interrupt:
SP7021 system has its own RTC device driver (rtc-sunplus.c).
The user can set the RTC wake-up time through rtc-sunplus.c.
The IOP code does not need to increase the RTC subsystem function,
set the RTC register.	When the linux kernel system is poweroff.
Only the 8051 CPU has power and can monitor the RTC wake-up interrupt.

PMC in power management purpose:
Add sp_iop_poweroff() function. pm_power_off=sp_iop_poweroff.
When the poweroff command is executed.
The 8051 has a register to control the power-on and power-off 
of the system. If you turn off the power through the 8051 
register(DEF_PWR_EN_0=0). The current measured by the circuit 
board is 0.4mA only. In order to save power.

Signed-off-by: Tony Huang <tonyhuang.sunplus@gmail.com>
---
Changes in v10:
 - Added sp_iop_poweroff function for poweroff command.

 MAINTAINERS                |   1 +
 drivers/misc/Kconfig       |  36 ++++
 drivers/misc/Makefile      |   1 +
 drivers/misc/sunplus_iop.c | 438 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 476 insertions(+)
 create mode 100644 drivers/misc/sunplus_iop.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 6f336c9..11ecefa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18246,6 +18246,7 @@ SUNPLUS IOP DRIVER
 M:	Tony Huang <tonyhuang.sunplus@gmail.com>
 S:	Maintained
 F:	Documentation/devicetree/bindings/misc/sunplu-iop.yaml
+F:	drivers/misc/sunplus_iop.c
 
 SUPERH
 M:	Yoshinori Sato <ysato@users.sourceforge.jp>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 0f5a49f..3106f15 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -470,6 +470,42 @@ 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
+	  This driver is load 8051 bin code.
+	  Processor for I/O control:
+	  SP7021 has its own GPIO device driver.
+	  The user can configure the gpio pin for 8051 use.
+	  8051 support wake-up with IR key after system poweroff.
+
+	  Monitor RTC interrupt:
+	  SP7021 system has its own RTC device driver (rtc-sunplus.c).
+	  The user can set the RTC wake-up time through rtc-sunplus.c.
+	  The IOP code does not need to increase the RTC subsystem function,
+	  set the RTC register.	When the linux kernel system is poweroff.
+	  Only the 8051 CPU has power and can monitor the RTC wake-up interrupt.
+
+	  PMC in power management purpose:
+	  Add sp_iop_poweroff() function. pm_power_off=sp_iop_poweroff.
+	  When the poweroff command is executed.
+	  The 8051 has a register to control the power-on and power-off of the system.
+	  If you turn off the power through the 8051 register(DEF_PWR_EN_0=0),
+	  The current measured by the circuit board is 0.4mA only. In order to save power.
+
+	  The IOP core is DQ8051, so also named IOP8051.
+	  Need Install DQ8051, The DQ8051 bin file generated by keil C.
+	  We will provide users with 8051 normal and standby source code.
+	  Path: https://sunplus.atlassian.net/wiki/spaces/doc/pages/610172933/
+	  How+to+use+I+O+processor+8051+of+SP7021#5.-Write-C-or-assembly-source-files-for-IOP
+	  Users can follow the operation steps to generate normal.bin and standby.bin.
+	  Path: https://sunplus.atlassian.net/wiki/spaces/doc/pages/466190338/26.+IOP8051
+	  26.5?How To Create 8051 bin file
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called sunplus_iop.
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index a086197..eafeab6 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -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/
diff --git a/drivers/misc/sunplus_iop.c b/drivers/misc/sunplus_iop.c
new file mode 100644
index 0000000..03301b4
--- /dev/null
+++ b/drivers/misc/sunplus_iop.c
@@ -0,0 +1,438 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * The IOP driver for Sunplus SP7021
+ *
+ * Copyright (C) 2021 Sunplus Technology Inc.
+ *
+ * All Rights Reserved.
+ */
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/firmware.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/of_gpio.h>
+
+enum IOP_Status_e {
+	IOP_SUCCESS,		/* successful */
+	IOP_ERR_IOP_BUSY,	/* IOP is busy */
+};
+
+/* moon0 register offset */
+#define IOP_CLKEN0	0x04
+#define IOP_RESET0	0x54
+
+/* IOP register offset */
+#define IOP_CONTROL	0x00
+#define IOP_DATA0	0x20
+#define IOP_DATA1	0x24
+#define IOP_DATA2	0x28
+#define IOP_DATA3	0x2c
+#define IOP_DATA4	0x30
+#define IOP_DATA5	0x34
+#define IOP_DATA6	0x38
+#define IOP_DATA7	0x3c
+#define IOP_DATA8	0x40
+#define IOP_DATA9	0x44
+#define IOP_DATA10	0x48
+#define IOP_DATA11	0x4c
+#define IOP_BASE_ADR_L	0x50
+#define IOP_BASE_ADR_H	0x54
+
+/* PMC register offset */
+#define IOP_PMC_TIMER		0x00
+#define IOP_PMC_CTRL		0x04
+#define IOP_XTAL27M_PASSWORD_I	0x08
+#define IOP_XTAL27M_PASSWORD_II	0x0c
+#define IOP_XTAL32K_PASSWORD_I	0x10
+#define IOP_XTAL32K_PASSWORD_II	0x14
+#define IOP_CLK27M_PASSWORD_I	0x18
+#define IOP_CLK27M_PASSWORD_II	0x1c
+#define IOP_PMC_TIMER2		0x20
+
+#define NORMAL_CODE_MAX_SIZE 0X1000	/* Max size of normal.bin that can be received */
+#define STANDBY_CODE_MAX_SIZE 0x4000	/* Max size of standby.bin that can be received */
+struct sp_iop {
+	struct device *dev;
+	struct mutex write_lock;	/* avoid parallel access */
+	void __iomem *iop_regs;
+	void __iomem *pmc_regs;
+	void __iomem *moon0_regs;
+	int irq;
+	int gpio_wakeup;
+	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;
+	unsigned char bin_code_mode;
+};
+
+static struct sp_iop *iop_poweroff;
+
+static void sp_iop_run_normal_code(struct sp_iop *iop)
+{
+	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, iop->moon0_regs + IOP_CLKEN0);
+
+	reg = readl(iop->iop_regs + IOP_CONTROL);
+	reg |= 0x01;
+	writel(reg, iop->iop_regs + IOP_CONTROL);
+
+	reg = readl(iop->iop_regs + IOP_CONTROL);
+	reg &= ~(0x8000);
+	writel(reg, iop->iop_regs + IOP_CONTROL);
+
+	reg = readl(iop->iop_regs + IOP_CONTROL);
+	reg |= 0x0200;// disable watchdog event reset IOP
+	writel(reg, iop->iop_regs + IOP_CONTROL);
+
+	reg = (iop->iop_mem_start & 0xFFFF);
+	writel(reg, iop->iop_regs + IOP_BASE_ADR_L);
+	reg	= (iop->iop_mem_start >> 16);
+	writel(reg, iop->iop_regs + IOP_BASE_ADR_H);
+
+	reg = readl(iop->iop_regs + IOP_CONTROL);
+	reg &= ~(0x01);
+	writel(reg, iop->iop_regs + IOP_CONTROL);
+	iop->bin_code_mode = 0;
+}
+
+static void sp_iop_run_standby_code(struct sp_iop *iop)
+{
+	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, iop->moon0_regs + IOP_CLKEN0);
+
+	reg = readl(iop->iop_regs + IOP_CONTROL);
+	reg |= 0x01;
+	writel(reg, iop->iop_regs + IOP_CONTROL);
+
+	reg = readl(iop->iop_regs + IOP_CONTROL);
+	reg &= ~(0x8000);
+	writel(reg, iop->iop_regs + IOP_CONTROL);
+
+	reg = readl(iop->iop_regs + IOP_CONTROL);
+	reg |= 0x0200;// disable watchdog event reset IOP
+	writel(reg, iop->iop_regs + IOP_CONTROL);
+
+	reg = (iop->iop_mem_start & 0xFFFF);
+	writel(reg, iop->iop_regs + IOP_BASE_ADR_L);
+	reg = (iop->iop_mem_start >> 16);
+	writel(reg, iop->iop_regs + IOP_BASE_ADR_H);
+
+	reg = readl(iop->iop_regs + IOP_CONTROL);
+	reg &= ~(0x01);
+	writel(reg, iop->iop_regs + IOP_CONTROL);
+	iop->bin_code_mode = 1;
+}
+
+/* 8051 informs linux kerenl. 8051 has been switched to standby.bin code. */
+#define IOP_READY	0x0004
+#define RISC_READY	0x0008
+
+/* System linux kernel tells 8051 which  gpio pin to wake-up through. */
+#define WAKEUP_PIN	0xFE02
+
+/* System linux kernel tells 8051 to execute S1 or S3 mode. */
+#define S1	0x5331
+#define S3	0x5333
+
+static int sp_iop_s3mode(struct device *dev, struct sp_iop *iop)
+{
+	unsigned int reg;
+	int ret, value;
+
+	/* PMC set */
+	writel(0x00010001, iop->pmc_regs + IOP_PMC_TIMER);
+	reg = readl(iop->pmc_regs + IOP_PMC_CTRL);
+	/* disable system reset PMC, enalbe power down IOP Domain, enable gating clock 27Mhz */
+	reg |= 0x23;
+	writel(reg, iop->pmc_regs + IOP_PMC_CTRL);
+
+	writel(0x55aa00ff, iop->pmc_regs + IOP_XTAL27M_PASSWORD_I);
+	writel(0x00ff55aa, iop->pmc_regs + IOP_XTAL27M_PASSWORD_II);
+	writel(0xaa00ff55, iop->pmc_regs + IOP_XTAL32K_PASSWORD_I);
+	writel(0xff55aa00, iop->pmc_regs + IOP_XTAL32K_PASSWORD_II);
+	writel(0xaaff0055, iop->pmc_regs + IOP_CLK27M_PASSWORD_I);
+	writel(0x5500aaff, iop->pmc_regs + IOP_CLK27M_PASSWORD_II);
+	writel(0x01000100, iop->pmc_regs + IOP_PMC_TIMER2);
+
+	/* IOP Hardware IP reset */
+	reg = readl(iop->moon0_regs + IOP_RESET0);
+	reg |= 0x10;
+	writel(reg, (iop->moon0_regs + IOP_RESET0));
+	reg &= ~(0x10);
+	writel(reg, (iop->moon0_regs + IOP_RESET0));
+
+	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));
+
+	writel(WAKEUP_PIN, iop->iop_regs + IOP_DATA0);
+	writel(iop->gpio_wakeup, iop->iop_regs + IOP_DATA1);
+
+	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA2, value,
+				 (value & IOP_READY) == IOP_READY, 1000, 10000);
+	if (ret) {
+		dev_err(dev, "timed out\n");
+		return ret;
+	}
+
+	reg = RISC_READY;
+	writel(reg, iop->iop_regs + IOP_DATA2);
+	reg = 0x0000;
+	writel(reg, iop->iop_regs + IOP_DATA5);
+	reg = 0x0060;
+	writel(reg, iop->iop_regs + IOP_DATA6);
+
+	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA7, value,
+				 value == 0xaaaa, 1000, 10000);
+	if (ret) {
+		dev_err(dev, "timed out\n");
+		return ret;
+	}
+
+	/* 8051 bin file call Ultra low function. */
+	writel(0xdd, iop->iop_regs + IOP_DATA1);
+	/*
+	 * When the execution is here, the system linux kernel
+	 * is about to be powered off
+	 * The purpose of mdelay(10): Do not let the system linux
+	 * kernel continue to run other programs.
+	 */
+	mdelay(10);
+	return 0;
+}
+
+static int sp_iop_s1mode(struct device *dev, struct sp_iop *iop)
+{
+	int ret, value;
+
+	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA2, value,
+				 (value & IOP_READY) == IOP_READY, 1000, 10000);
+	if (ret) {
+		dev_err(dev, "timed out\n");
+		return ret;
+	}
+
+	writel(RISC_READY, iop->iop_regs + IOP_DATA2);
+	writel(0x0000, iop->iop_regs + IOP_DATA5);
+	writel(0x0060, iop->iop_regs + IOP_DATA6);
+
+	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA7, value,
+				 value == 0xaaaa, 1000, 10000);
+	if (ret) {
+		dev_err(dev, "timed out\n");
+		return ret;
+	}
+
+	/* 8051 bin file call S1_mode function. */
+	writel(0xee, iop->iop_regs + IOP_DATA1);
+	/*
+	 * When the execution is here, the system linux kernel
+	 * is about to be powered off
+	 * The purpose of mdelay(10): Do not let the system linux
+	 * kernel continue to run other programs.
+	 */
+	mdelay(10);
+	return 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 void sp_iop_poweroff(void)
+{
+	struct sp_iop *iop = iop_poweroff;
+	unsigned int ret, value;
+
+	value = readl(iop->iop_regs + IOP_DATA11);
+	sp_iop_run_standby_code(iop);
+
+	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA0, value,
+				 value == 0x2222, 1000, 100000);
+	if (ret)
+		dev_warn(iop->dev, "timed out\n");
+
+	if (value == S1)
+		sp_iop_s1mode(iop->dev, iop);
+	else
+		sp_iop_s3mode(iop->dev, iop);
+}
+
+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);
+	if (!iop) {
+		ret	= -ENOMEM;
+		goto fail_kmalloc;
+	}
+	/* init */
+	mutex_init(&iop->write_lock);
+	ret = sp_iop_get_resources(pdev, iop);
+
+	// Get reserve address
+	memnp = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
+	if (!memnp) {
+		dev_err(&pdev->dev, "no memory-region node\n");
+		return -EINVAL;
+	}
+
+	rc = of_address_to_resource(memnp, 0, &mem_res);
+	of_node_put(memnp);
+	if (rc) {
+		dev_err(&pdev->dev, "failed to translate memory-region to a resource\n");
+		return -EINVAL;
+	}
+
+	iop->dev = &pdev->dev;
+	iop->iop_mem_start = mem_res.start;
+	iop->iop_mem_size = resource_size(&mem_res);
+
+	/*
+	 * 8051 has two bin files, normal.bin and standby.bin in rootfs.
+	 * Normally, 8051 executes normal.bin code. Normal.bin code size can exceed 16K.
+	 * When system linux kernel is shutdown, 8051 is to execute standby.bin code.
+	 * Standby.bin code cannot exceed 16K bytes. Because 8051 Icache size is 16k.
+	 * 8051 runs with standby.bin code in the Icache before the system(linux kernel)
+	 * is poweroff.
+	 */
+	ret = sp_iop_get_normal_code(&pdev->dev, iop);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "get normal code err=%d\n", ret);
+		return ret;
+	}
+
+	ret = sp_iop_get_standby_code(&pdev->dev, iop);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "get standby code err=%d\n", ret);
+		return ret;
+	}
+
+	sp_iop_run_normal_code(iop);
+	platform_set_drvdata(pdev, iop);
+	iop->gpio_wakeup = of_get_named_gpio(pdev->dev.of_node, "iop-wakeup", 0);
+	iop_poweroff = iop;
+	pm_power_off = sp_iop_poweroff;
+	return 0;
+
+fail_kmalloc:
+	return ret;
+}
+
+static int sp_iop_remove(struct platform_device *pdev)
+{
+	pm_power_off = NULL;
+	return 0;
+}
+
+static const struct of_device_id sp_iop_of_match[] = {
+	{ .compatible = "sunplus,sp7021-iop" },
+	{ /* sentinel */ },
+};
+
+MODULE_DEVICE_TABLE(of, sp_iop_of_match);
+
+static struct platform_driver sp_iop_platform_driver = {
+	.probe		= sp_iop_platform_driver_probe,
+	.remove		= sp_iop_remove,
+	.driver = {
+		.name	= "sunplus,sp7021-iop",
+		.of_match_table = sp_iop_of_match,
+	}
+};
+
+module_platform_driver(sp_iop_platform_driver);
+
+MODULE_AUTHOR("Tony Huang <tonyhuang.sunplus@gmail.com>");
+MODULE_DESCRIPTION("Sunplus IOP Driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

Re: [PATCH v10 2/2] misc: Add iop driver for Sunplus SP7021

[Arnd Bergmann]

On Mon, Mar 7, 2022 at 6:25 AM Tony Huang <tonyhuang.sunplus@gmail.com> wrote:
>
> This driver is load 8051 bin code.
> Processor for I/O control:
> SP7021 has its own GPIO device driver.
> The user can configure the gpio pin for 8051 use.
> The 8051 support wake-up with IR key after system poweroff.
>
> Monitor RTC interrupt:
> SP7021 system has its own RTC device driver (rtc-sunplus.c).
> The user can set the RTC wake-up time through rtc-sunplus.c.
> The IOP code does not need to increase the RTC subsystem function,
> set the RTC register.   When the linux kernel system is poweroff.
> Only the 8051 CPU has power and can monitor the RTC wake-up interrupt.
>
> PMC in power management purpose:
> Add sp_iop_poweroff() function. pm_power_off=sp_iop_poweroff.
> When the poweroff command is executed.
> The 8051 has a register to control the power-on and power-off
> of the system. If you turn off the power through the 8051
> register(DEF_PWR_EN_0=0). The current measured by the circuit
> board is 0.4mA only. In order to save power.
> Changes in v10:
>  - Added sp_iop_poweroff function for poweroff command.
>

Thank you for finally adding support for one of the functions of the
hardware!

> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index 0f5a49f..3106f15 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -470,6 +470,42 @@ 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
> +         This driver is load 8051 bin code.
> +         Processor for I/O control:
> +         SP7021 has its own GPIO device driver.
> +         The user can configure the gpio pin for 8051 use.
> +         8051 support wake-up with IR key after system poweroff.
> +
> +         Monitor RTC interrupt:
> +         SP7021 system has its own RTC device driver (rtc-sunplus.c).
> +         The user can set the RTC wake-up time through rtc-sunplus.c.
> +         The IOP code does not need to increase the RTC subsystem function,
> +         set the RTC register. When the linux kernel system is poweroff.
> +         Only the 8051 CPU has power and can monitor the RTC wake-up interrupt.
> +
> +         PMC in power management purpose:
> +         Add sp_iop_poweroff() function. pm_power_off=sp_iop_poweroff.
> +         When the poweroff command is executed.
> +         The 8051 has a register to control the power-on and power-off of the system.
> +         If you turn off the power through the 8051 register(DEF_PWR_EN_0=0),
> +         The current measured by the circuit board is 0.4mA only. In order to save power.

The description sounds misleading here: At the moment, you only add
support for poweroff, not for system suspend.

Maybe leave out the description about the RTC and power savings here
and only describe the bits that the driver actually implements. Can you
add some text to the patch changelog to describe what your plans are
for supporting suspend mode, and clarify which functions are implemented
already, compared to those that are possible in hardware but not part
of this patch series?


> +static void sp_iop_run_standby_code(struct sp_iop *iop)
> +{
> +       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);

'standby' mode usually refers to 'suspend-to-ram' mode, which is something
the driver does not (yet) support. Can you clarify whether that means you
want to add it later, or you just used the wrong term here?

> +
> +/* 8051 informs linux kerenl. 8051 has been switched to standby.bin code. */
> +#define IOP_READY      0x0004
> +#define RISC_READY     0x0008
> +
> +/* System linux kernel tells 8051 which  gpio pin to wake-up through. */
> +#define WAKEUP_PIN     0xFE02
> +
> +/* System linux kernel tells 8051 to execute S1 or S3 mode. */
> +#define S1     0x5331
> +#define S3     0x5333

Again, the names here seem misleading: in power management terms,
's1' and 's3' typically refer to types of system power saving modes that
are different from power-off or suspend-to-disk. Maybe try to use less
confusing terms here?

> +       /* IOP Hardware IP reset */
> +       reg = readl(iop->moon0_regs + IOP_RESET0);
> +       reg |= 0x10;
> +       writel(reg, (iop->moon0_regs + IOP_RESET0));
> +       reg &= ~(0x10);
> +       writel(reg, (iop->moon0_regs + IOP_RESET0));

This looks like you are writing individual bits into a shared
clock/reset controller that is part of the SoC. If this is the case,
it would be better to make that a separate driver that owns
the moon0_regs registers and exposes them through the
clk and reset subsystem interfaces (drivers/clk, drivers/reset).

> +static void sp_iop_poweroff(void)
> +{
> +       struct sp_iop *iop = iop_poweroff;
> +       unsigned int ret, value;
> +
> +       value = readl(iop->iop_regs + IOP_DATA11);
> +       sp_iop_run_standby_code(iop);
> +
> +       ret = readl_poll_timeout(iop->iop_regs + IOP_DATA0, value,
> +                                value == 0x2222, 1000, 100000);
> +       if (ret)
> +               dev_warn(iop->dev, "timed out\n");
> +
> +       if (value == S1)
> +               sp_iop_s1mode(iop->dev, iop);
> +       else
> +               sp_iop_s3mode(iop->dev, iop);
> +}

The power-off logic should probably be a separate driver in drivers/power/reset/
that calls into the common driver.

        Arnd

Re: [PATCH v10 1/2] dt-binding: misc: Add iop yaml file for Sunplus SP7021

[Krzysztof Kozlowski]

On 07/03/2022 06:25, Tony Huang wrote:
> Add iop yaml file for Sunplus SP7021

subject prefix is "dt-bindings", not "dt-binding".

> 
> Reviewed-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Tony Huang <tonyhuang.sunplus@gmail.com>
> ---
> Changes in v10:
>  -No change
> 
>  .../devicetree/bindings/misc/sunplus-iop.yaml      | 76 ++++++++++++++++++++++
>  MAINTAINERS                                        |  5 ++
>  2 files changed, 81 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/misc/sunplus-iop.yaml
> 
> diff --git a/Documentation/devicetree/bindings/misc/sunplus-iop.yaml b/Documentation/devicetree/bindings/misc/sunplus-iop.yaml
> new file mode 100644
> index 0000000..b37e697
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/misc/sunplus-iop.yaml
> @@ -0,0 +1,76 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) Sunplus Ltd. Co. 2021
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/misc/sunplus-iop.yaml#

Use file name in "vendor,name" format, so "sunplus,iop.yaml".

> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Sunplus IOP(8051) controller
> +
> +maintainers:
> +  - Tony Huang <tonyhuang.sunplus@gmail.com>
> +
> +description: |
> +  Processor for I/O control, RTC wake-up procedure management,
> +  and cooperation with CPU&PMC in power management.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - sunplus,sp7021-iop
> +
> +  reg:
> +    items:
> +      - description: IOP registers regions
> +      - description: PMC registers regions
> +      - description: MOON0 registers regions
> +
> +  reg-names:
> +    items:
> +      - const: iop
> +      - const: iop_pmc
> +      - const: moon0
> +
> +  interrupts:
> +    items:
> +      - description: IOP_INT0. IOP to system Interrupt 0.
> +                     Sent by IOP to system RISC.
> +      - description: IOP_INT1. IOP to System Interrupt 1.
> +                     Sent by IOP to system RISC.
> +
> +  memory-region:
> +    maxItems: 1
> +
> +  wakeup-gpios:
> +    description: When the linux kernel system is powered off.
> +      8051 is always powered. 8051 cand receive external signals
> +      according to this gpio pin. 8051 receives external signal
> +      through gpio pin. 8051 can power on linux kernel system.

How many items (maxItems)? Unless Rob already asked about it...

> +
> +required:
> +  - compatible
> +  - reg
> +  - reg-names
> +  - interrupts
> +  - memory-region
> +  - wakeup-gpios
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/gpio/gpio.h>
> +    iop: iop@9c000400 {
> +        compatible = "sunplus,sp7021-iop";
> +        reg = <0x9c000400 0x80>, <0x9c003100 0x80>, <0x9c000000 0x80>;
> +        reg-names = "iop", "iop_pmc", "moon0";
> +        interrupt-parent = <&intc>;
> +        interrupts = <41 IRQ_TYPE_LEVEL_HIGH>, <42 IRQ_TYPE_LEVEL_HIGH>;
> +        memory-region = <&iop_reserve>;
> +        pinctrl-names = "default";
> +        pinctrl-0 = <&iop_pins>;
> +        wakeup-gpios = <&pctl 1 GPIO_ACTIVE_HIGH>;
> +    };
> +...
> diff --git a/MAINTAINERS b/MAINTAINERS
> index fb18ce7..6f336c9 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -18242,6 +18242,11 @@ L:	netdev@vger.kernel.org
>  S:	Maintained
>  F:	drivers/net/ethernet/dlink/sundance.c
>  
> +SUNPLUS IOP DRIVER
> +M:	Tony Huang <tonyhuang.sunplus@gmail.com>
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/misc/sunplu-iop.yaml

Wrong path.

> +
>  SUPERH
>  M:	Yoshinori Sato <ysato@users.sourceforge.jp>
>  M:	Rich Felker <dalias@libc.org>


Best regards,
Krzysztof

Re: [PATCH v10 2/2] misc: Add iop driver for Sunplus SP7021

[Krzysztof Kozlowski]

On 07/03/2022 06:25, Tony Huang wrote:
> This driver is load 8051 bin code.
> Processor for I/O control:
> SP7021 has its own GPIO device driver.
> The user can configure the gpio pin for 8051 use.
> The 8051 support wake-up with IR key after system poweroff.
> 
> Monitor RTC interrupt:
> SP7021 system has its own RTC device driver (rtc-sunplus.c).
> The user can set the RTC wake-up time through rtc-sunplus.c.
> The IOP code does not need to increase the RTC subsystem function,
> set the RTC register.	When the linux kernel system is poweroff.
> Only the 8051 CPU has power and can monitor the RTC wake-up interrupt.
> 
> PMC in power management purpose:
> Add sp_iop_poweroff() function. pm_power_off=sp_iop_poweroff.
> When the poweroff command is executed.
> The 8051 has a register to control the power-on and power-off 
> of the system. If you turn off the power through the 8051 
> register(DEF_PWR_EN_0=0). The current measured by the circuit 
> board is 0.4mA only. In order to save power.
> 
> Signed-off-by: Tony Huang <tonyhuang.sunplus@gmail.com>
> ---
> Changes in v10:
>  - Added sp_iop_poweroff function for poweroff command.
> 
>  MAINTAINERS                |   1 +
>  drivers/misc/Kconfig       |  36 ++++
>  drivers/misc/Makefile      |   1 +
>  drivers/misc/sunplus_iop.c | 438 +++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 476 insertions(+)
>  create mode 100644 drivers/misc/sunplus_iop.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 6f336c9..11ecefa 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -18246,6 +18246,7 @@ SUNPLUS IOP DRIVER
>  M:	Tony Huang <tonyhuang.sunplus@gmail.com>
>  S:	Maintained
>  F:	Documentation/devicetree/bindings/misc/sunplu-iop.yaml
> +F:	drivers/misc/sunplus_iop.c
>  
>  SUPERH
>  M:	Yoshinori Sato <ysato@users.sourceforge.jp>
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index 0f5a49f..3106f15 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -470,6 +470,42 @@ 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
> +	  This driver is load 8051 bin code.
> +	  Processor for I/O control:
> +	  SP7021 has its own GPIO device driver.
> +	  The user can configure the gpio pin for 8051 use.
> +	  8051 support wake-up with IR key after system poweroff.
> +
> +	  Monitor RTC interrupt:
> +	  SP7021 system has its own RTC device driver (rtc-sunplus.c).
> +	  The user can set the RTC wake-up time through rtc-sunplus.c.
> +	  The IOP code does not need to increase the RTC subsystem function,
> +	  set the RTC register.	When the linux kernel system is poweroff.
> +	  Only the 8051 CPU has power and can monitor the RTC wake-up interrupt.
> +
> +	  PMC in power management purpose:
> +	  Add sp_iop_poweroff() function. pm_power_off=sp_iop_poweroff.
> +	  When the poweroff command is executed.
> +	  The 8051 has a register to control the power-on and power-off of the system.
> +	  If you turn off the power through the 8051 register(DEF_PWR_EN_0=0),
> +	  The current measured by the circuit board is 0.4mA only. In order to save power.
> +
> +	  The IOP core is DQ8051, so also named IOP8051.
> +	  Need Install DQ8051, The DQ8051 bin file generated by keil C.
> +	  We will provide users with 8051 normal and standby source code.
> +	  Path: https://sunplus.atlassian.net/wiki/spaces/doc/pages/610172933/
> +	  How+to+use+I+O+processor+8051+of+SP7021#5.-Write-C-or-assembly-source-files-for-IOP
> +	  Users can follow the operation steps to generate normal.bin and standby.bin.
> +	  Path: https://sunplus.atlassian.net/wiki/spaces/doc/pages/466190338/26.+IOP8051
> +	  26.5?How To Create 8051 bin file
> +
> +	  This driver can also be built as a module.  If so, the module
> +	  will be called sunplus_iop.
> +
>  source "drivers/misc/c2port/Kconfig"
>  source "drivers/misc/eeprom/Kconfig"
>  source "drivers/misc/cb710/Kconfig"
> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> index a086197..eafeab6 100644
> --- a/drivers/misc/Makefile
> +++ b/drivers/misc/Makefile
> @@ -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/
> diff --git a/drivers/misc/sunplus_iop.c b/drivers/misc/sunplus_iop.c
> new file mode 100644
> index 0000000..03301b4
> --- /dev/null
> +++ b/drivers/misc/sunplus_iop.c
> @@ -0,0 +1,438 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * The IOP driver for Sunplus SP7021
> + *
> + * Copyright (C) 2021 Sunplus Technology Inc.
> + *
> + * All Rights Reserved.
> + */
> +#include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/firmware.h>
> +#include <linux/iopoll.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/of_address.h>
> +#include <linux/of_gpio.h>
> +

Except comments from Arnd also:

> +enum IOP_Status_e {
> +	IOP_SUCCESS,		/* successful */
> +	IOP_ERR_IOP_BUSY,	/* IOP is busy */
> +};

please do not redefine true/false or ERRNO.

> +
> +/* moon0 register offset */
> +#define IOP_CLKEN0	0x04
> +#define IOP_RESET0	0x54
> +
> +/* IOP register offset */
> +#define IOP_CONTROL	0x00
> +#define IOP_DATA0	0x20
> +#define IOP_DATA1	0x24
> +#define IOP_DATA2	0x28
> +#define IOP_DATA3	0x2c
> +#define IOP_DATA4	0x30
> +#define IOP_DATA5	0x34
> +#define IOP_DATA6	0x38
> +#define IOP_DATA7	0x3c
> +#define IOP_DATA8	0x40
> +#define IOP_DATA9	0x44
> +#define IOP_DATA10	0x48
> +#define IOP_DATA11	0x4c
> +#define IOP_BASE_ADR_L	0x50
> +#define IOP_BASE_ADR_H	0x54
> +
> +/* PMC register offset */
> +#define IOP_PMC_TIMER		0x00
> +#define IOP_PMC_CTRL		0x04
> +#define IOP_XTAL27M_PASSWORD_I	0x08
> +#define IOP_XTAL27M_PASSWORD_II	0x0c
> +#define IOP_XTAL32K_PASSWORD_I	0x10
> +#define IOP_XTAL32K_PASSWORD_II	0x14
> +#define IOP_CLK27M_PASSWORD_I	0x18
> +#define IOP_CLK27M_PASSWORD_II	0x1c
> +#define IOP_PMC_TIMER2		0x20
> +
> +#define NORMAL_CODE_MAX_SIZE 0X1000	/* Max size of normal.bin that can be received */
> +#define STANDBY_CODE_MAX_SIZE 0x4000	/* Max size of standby.bin that can be received */

Empty line.

> +struct sp_iop {
> +	struct device *dev;
> +	struct mutex write_lock;	/* avoid parallel access */

This comment is useless. It is obvious that mutex is used to avoid
parallel access, what else could it be used?

Instead, you need to describe which members/variables/parts of code are
protected with the mutex.

> +	void __iomem *iop_regs;
> +	void __iomem *pmc_regs;
> +	void __iomem *moon0_regs;
> +	int irq;
> +	int gpio_wakeup;
> +	unsigned char iop_normal_code[NORMAL_CODE_MAX_SIZE];
> +	unsigned char iop_standby_code[STANDBY_CODE_MAX_SIZE];

Why not using firmware? include/linux/firmware.h? Do not reimplement
existing solutions...

> +	resource_size_t iop_mem_start;
> +	resource_size_t iop_mem_size;
> +	unsigned char bin_code_mode;
> +};
> +
> +static struct sp_iop *iop_poweroff;
> +
> +static void sp_iop_run_normal_code(struct sp_iop *iop)
> +{
> +	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, iop->moon0_regs + IOP_CLKEN0);
> +
> +	reg = readl(iop->iop_regs + IOP_CONTROL);
> +	reg |= 0x01;
> +	writel(reg, iop->iop_regs + IOP_CONTROL);
> +
> +	reg = readl(iop->iop_regs + IOP_CONTROL);
> +	reg &= ~(0x8000);
> +	writel(reg, iop->iop_regs + IOP_CONTROL);
> +
> +	reg = readl(iop->iop_regs + IOP_CONTROL);
> +	reg |= 0x0200;// disable watchdog event reset IOP
> +	writel(reg, iop->iop_regs + IOP_CONTROL);
> +
> +	reg = (iop->iop_mem_start & 0xFFFF);
> +	writel(reg, iop->iop_regs + IOP_BASE_ADR_L);
> +	reg	= (iop->iop_mem_start >> 16);
> +	writel(reg, iop->iop_regs + IOP_BASE_ADR_H);
> +
> +	reg = readl(iop->iop_regs + IOP_CONTROL);
> +	reg &= ~(0x01);
> +	writel(reg, iop->iop_regs + IOP_CONTROL);
> +	iop->bin_code_mode = 0;
> +}
> +
> +static void sp_iop_run_standby_code(struct sp_iop *iop)
> +{
> +	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, iop->moon0_regs + IOP_CLKEN0);
> +
> +	reg = readl(iop->iop_regs + IOP_CONTROL);
> +	reg |= 0x01;
> +	writel(reg, iop->iop_regs + IOP_CONTROL);
> +
> +	reg = readl(iop->iop_regs + IOP_CONTROL);
> +	reg &= ~(0x8000);
> +	writel(reg, iop->iop_regs + IOP_CONTROL);
> +
> +	reg = readl(iop->iop_regs + IOP_CONTROL);
> +	reg |= 0x0200;// disable watchdog event reset IOP
> +	writel(reg, iop->iop_regs + IOP_CONTROL);
> +
> +	reg = (iop->iop_mem_start & 0xFFFF);
> +	writel(reg, iop->iop_regs + IOP_BASE_ADR_L);
> +	reg = (iop->iop_mem_start >> 16);
> +	writel(reg, iop->iop_regs + IOP_BASE_ADR_H);
> +
> +	reg = readl(iop->iop_regs + IOP_CONTROL);
> +	reg &= ~(0x01);
> +	writel(reg, iop->iop_regs + IOP_CONTROL);
> +	iop->bin_code_mode = 1;
> +}
> +
> +/* 8051 informs linux kerenl. 8051 has been switched to standby.bin code. */
> +#define IOP_READY	0x0004
> +#define RISC_READY	0x0008
> +
> +/* System linux kernel tells 8051 which  gpio pin to wake-up through. */
> +#define WAKEUP_PIN	0xFE02
> +
> +/* System linux kernel tells 8051 to execute S1 or S3 mode. */
> +#define S1	0x5331
> +#define S3	0x5333

Keep defines together, so beginning of file.

> +
> +static int sp_iop_s3mode(struct device *dev, struct sp_iop *iop)
> +{
> +	unsigned int reg;
> +	int ret, value;
> +
> +	/* PMC set */
> +	writel(0x00010001, iop->pmc_regs + IOP_PMC_TIMER);
> +	reg = readl(iop->pmc_regs + IOP_PMC_CTRL);
> +	/* disable system reset PMC, enalbe power down IOP Domain, enable gating clock 27Mhz */
> +	reg |= 0x23;
> +	writel(reg, iop->pmc_regs + IOP_PMC_CTRL);
> +
> +	writel(0x55aa00ff, iop->pmc_regs + IOP_XTAL27M_PASSWORD_I);
> +	writel(0x00ff55aa, iop->pmc_regs + IOP_XTAL27M_PASSWORD_II);
> +	writel(0xaa00ff55, iop->pmc_regs + IOP_XTAL32K_PASSWORD_I);
> +	writel(0xff55aa00, iop->pmc_regs + IOP_XTAL32K_PASSWORD_II);
> +	writel(0xaaff0055, iop->pmc_regs + IOP_CLK27M_PASSWORD_I);
> +	writel(0x5500aaff, iop->pmc_regs + IOP_CLK27M_PASSWORD_II);
> +	writel(0x01000100, iop->pmc_regs + IOP_PMC_TIMER2);
> +
> +	/* IOP Hardware IP reset */
> +	reg = readl(iop->moon0_regs + IOP_RESET0);
> +	reg |= 0x10;
> +	writel(reg, (iop->moon0_regs + IOP_RESET0));
> +	reg &= ~(0x10);
> +	writel(reg, (iop->moon0_regs + IOP_RESET0));
> +
> +	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));
> +
> +	writel(WAKEUP_PIN, iop->iop_regs + IOP_DATA0);
> +	writel(iop->gpio_wakeup, iop->iop_regs + IOP_DATA1);
> +
> +	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA2, value,
> +				 (value & IOP_READY) == IOP_READY, 1000, 10000);
> +	if (ret) {
> +		dev_err(dev, "timed out\n");
> +		return ret;
> +	}
> +
> +	reg = RISC_READY;
> +	writel(reg, iop->iop_regs + IOP_DATA2);
> +	reg = 0x0000;
> +	writel(reg, iop->iop_regs + IOP_DATA5);
> +	reg = 0x0060;
> +	writel(reg, iop->iop_regs + IOP_DATA6);
> +
> +	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA7, value,
> +				 value == 0xaaaa, 1000, 10000);
> +	if (ret) {
> +		dev_err(dev, "timed out\n");
> +		return ret;
> +	}
> +
> +	/* 8051 bin file call Ultra low function. */
> +	writel(0xdd, iop->iop_regs + IOP_DATA1);
> +	/*
> +	 * When the execution is here, the system linux kernel
> +	 * is about to be powered off
> +	 * The purpose of mdelay(10): Do not let the system linux
> +	 * kernel continue to run other programs.
> +	 */
> +	mdelay(10);
> +	return 0;
> +}
> +
> +static int sp_iop_s1mode(struct device *dev, struct sp_iop *iop)
> +{
> +	int ret, value;
> +
> +	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA2, value,
> +				 (value & IOP_READY) == IOP_READY, 1000, 10000);
> +	if (ret) {
> +		dev_err(dev, "timed out\n");
> +		return ret;
> +	}
> +
> +	writel(RISC_READY, iop->iop_regs + IOP_DATA2);
> +	writel(0x0000, iop->iop_regs + IOP_DATA5);
> +	writel(0x0060, iop->iop_regs + IOP_DATA6);
> +
> +	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA7, value,
> +				 value == 0xaaaa, 1000, 10000);

Hundreds of magical constants... Almost all of these should be defined
or described.

> +	if (ret) {
> +		dev_err(dev, "timed out\n");
> +		return ret;
> +	}
> +
> +	/* 8051 bin file call S1_mode function. */
> +	writel(0xee, iop->iop_regs + IOP_DATA1);
> +	/*
> +	 * When the execution is here, the system linux kernel
> +	 * is about to be powered off
> +	 * The purpose of mdelay(10): Do not let the system linux
> +	 * kernel continue to run other programs.
> +	 */
> +	mdelay(10);
> +	return 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 void sp_iop_poweroff(void)
> +{
> +	struct sp_iop *iop = iop_poweroff;
> +	unsigned int ret, value;
> +
> +	value = readl(iop->iop_regs + IOP_DATA11);
> +	sp_iop_run_standby_code(iop);
> +
> +	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA0, value,
> +				 value == 0x2222, 1000, 100000);
> +	if (ret)
> +		dev_warn(iop->dev, "timed out\n");
> +
> +	if (value == S1)
> +		sp_iop_s1mode(iop->dev, iop);
> +	else
> +		sp_iop_s3mode(iop->dev, iop);
> +}
> +
> +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);
> +	if (!iop) {
> +		ret	= -ENOMEM;

Wrong spacing before '='.

> +		goto fail_kmalloc;
> +	}
> +	/* init */

Remove useless comments.

> +	mutex_init(&iop->write_lock);

Where are lock/unlock operations? What is this all code? This looks like
half-baked solution...

> +	ret = sp_iop_get_resources(pdev, iop);
> +
> +	// Get reserve address

Keep consistent style. For comments /* is preferred. But definitely do
not mix one with another.

This code is difficult to read.

> +	memnp = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
> +	if (!memnp) {
> +		dev_err(&pdev->dev, "no memory-region node\n");
> +		return -EINVAL;
> +	}
> +
> +	rc = of_address_to_resource(memnp, 0, &mem_res);
> +	of_node_put(memnp);
> +	if (rc) {
> +		dev_err(&pdev->dev, "failed to translate memory-region to a resource\n");
> +		return -EINVAL;
> +	}
> +
> +	iop->dev = &pdev->dev;
> +	iop->iop_mem_start = mem_res.start;
> +	iop->iop_mem_size = resource_size(&mem_res);
> +
> +	/*
> +	 * 8051 has two bin files, normal.bin and standby.bin in rootfs.
> +	 * Normally, 8051 executes normal.bin code. Normal.bin code size can exceed 16K.
> +	 * When system linux kernel is shutdown, 8051 is to execute standby.bin code.
> +	 * Standby.bin code cannot exceed 16K bytes. Because 8051 Icache size is 16k.
> +	 * 8051 runs with standby.bin code in the Icache before the system(linux kernel)
> +	 * is poweroff.
> +	 */
> +	ret = sp_iop_get_normal_code(&pdev->dev, iop);
> +	if (ret != 0) {
> +		dev_err(&pdev->dev, "get normal code err=%d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = sp_iop_get_standby_code(&pdev->dev, iop);
> +	if (ret != 0) {
> +		dev_err(&pdev->dev, "get standby code err=%d\n", ret);
> +		return ret;
> +	}
> +
> +	sp_iop_run_normal_code(iop);
> +	platform_set_drvdata(pdev, iop);
> +	iop->gpio_wakeup = of_get_named_gpio(pdev->dev.of_node, "iop-wakeup", 0);
> +	iop_poweroff = iop;
> +	pm_power_off = sp_iop_poweroff;

Blank line. Before every such return. Please, open some recent drivers
and look at their code style.

> +	return 0;
> +
> +fail_kmalloc:
> +	return ret;
> +}
> +
> +static int sp_iop_remove(struct platform_device *pdev)
> +{
> +	pm_power_off = NULL;
> +	return 0;
> +}
> +
> +static const struct of_device_id sp_iop_of_match[] = {
> +	{ .compatible = "sunplus,sp7021-iop" },
> +	{ /* sentinel */ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, sp_iop_of_match);
> +
> +static struct platform_driver sp_iop_platform_driver = {
> +	.probe		= sp_iop_platform_driver_probe,
> +	.remove		= sp_iop_remove,
> +	.driver = {
> +		.name	= "sunplus,sp7021-iop",
> +		.of_match_table = sp_iop_of_match,
> +	}
> +};
> +
> +module_platform_driver(sp_iop_platform_driver);
> +
> +MODULE_AUTHOR("Tony Huang <tonyhuang.sunplus@gmail.com>");
> +MODULE_DESCRIPTION("Sunplus IOP Driver");
> +MODULE_LICENSE("GPL v2");


Best regards,
Krzysztof

RE: [PATCH v10 2/2] misc: Add iop driver for Sunplus SP7021

[Tony Huang 黃懷厚]

Dear Krzysztof:
I will modify the code to follow your comments 
Thanks

> Subject: Re: [PATCH v10 2/2] misc: Add iop driver for Sunplus SP7021
> 
> On 07/03/2022 06:25, Tony Huang wrote:
> > This driver is load 8051 bin code.
> > Processor for I/O control:
> > SP7021 has its own GPIO device driver.
> > The user can configure the gpio pin for 8051 use.
> > The 8051 support wake-up with IR key after system poweroff.
> >
> > Monitor RTC interrupt:
> > SP7021 system has its own RTC device driver (rtc-sunplus.c).
> > The user can set the RTC wake-up time through rtc-sunplus.c.
> > The IOP code does not need to increase the RTC subsystem function,
> > set the RTC register.	When the linux kernel system is poweroff.
> > Only the 8051 CPU has power and can monitor the RTC wake-up interrupt.
> >
> > PMC in power management purpose:
> > Add sp_iop_poweroff() function. pm_power_off=sp_iop_poweroff.
> > When the poweroff command is executed.
> > The 8051 has a register to control the power-on and power-off of the
> > system. If you turn off the power through the 8051
> > register(DEF_PWR_EN_0=0). The current measured by the circuit board is
> > 0.4mA only. In order to save power.
> >
> > Signed-off-by: Tony Huang <tonyhuang.sunplus@gmail.com>
> > ---
> > Changes in v10:
> >  - Added sp_iop_poweroff function for poweroff command.
> >
> >  MAINTAINERS                |   1 +
> >  drivers/misc/Kconfig       |  36 ++++
> >  drivers/misc/Makefile      |   1 +
> >  drivers/misc/sunplus_iop.c | 438
> > +++++++++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 476 insertions(+)
> >  create mode 100644 drivers/misc/sunplus_iop.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS index 6f336c9..11ecefa 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -18246,6 +18246,7 @@ SUNPLUS IOP DRIVER
> >  M:	Tony Huang <tonyhuang.sunplus@gmail.com>
> >  S:	Maintained
> >  F:	Documentation/devicetree/bindings/misc/sunplu-iop.yaml
> > +F:	drivers/misc/sunplus_iop.c
> >
> >  SUPERH
> >  M:	Yoshinori Sato <ysato@users.sourceforge.jp>
> > diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index
> > 0f5a49f..3106f15 100644
> > --- a/drivers/misc/Kconfig
> > +++ b/drivers/misc/Kconfig
> > @@ -470,6 +470,42 @@ 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
> > +	  This driver is load 8051 bin code.
> > +	  Processor for I/O control:
> > +	  SP7021 has its own GPIO device driver.
> > +	  The user can configure the gpio pin for 8051 use.
> > +	  8051 support wake-up with IR key after system poweroff.
> > +
> > +	  Monitor RTC interrupt:
> > +	  SP7021 system has its own RTC device driver (rtc-sunplus.c).
> > +	  The user can set the RTC wake-up time through rtc-sunplus.c.
> > +	  The IOP code does not need to increase the RTC subsystem function,
> > +	  set the RTC register.	When the linux kernel system is poweroff.
> > +	  Only the 8051 CPU has power and can monitor the RTC wake-up
> interrupt.
> > +
> > +	  PMC in power management purpose:
> > +	  Add sp_iop_poweroff() function. pm_power_off=sp_iop_poweroff.
> > +	  When the poweroff command is executed.
> > +	  The 8051 has a register to control the power-on and power-off of the
> system.
> > +	  If you turn off the power through the 8051 register(DEF_PWR_EN_0=0),
> > +	  The current measured by the circuit board is 0.4mA only. In order to
> save power.
> > +
> > +	  The IOP core is DQ8051, so also named IOP8051.
> > +	  Need Install DQ8051, The DQ8051 bin file generated by keil C.
> > +	  We will provide users with 8051 normal and standby source code.
> > +	  Path: https://sunplus.atlassian.net/wiki/spaces/doc/pages/610172933/
> > +
> How+to+use+I+O+processor+8051+of+SP7021#5.-Write-C-or-assembly-source-
> files-for-IOP
> > +	  Users can follow the operation steps to generate normal.bin and
> standby.bin.
> > +	  Path:
> https://sunplus.atlassian.net/wiki/spaces/doc/pages/466190338/26.+IOP8051
> > +	  26.5?How To Create 8051 bin file
> > +
> > +	  This driver can also be built as a module.  If so, the module
> > +	  will be called sunplus_iop.
> > +
> >  source "drivers/misc/c2port/Kconfig"
> >  source "drivers/misc/eeprom/Kconfig"
> >  source "drivers/misc/cb710/Kconfig"
> > diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index
> > a086197..eafeab6 100644
> > --- a/drivers/misc/Makefile
> > +++ b/drivers/misc/Makefile
> > @@ -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/
> > diff --git a/drivers/misc/sunplus_iop.c b/drivers/misc/sunplus_iop.c
> > new file mode 100644 index 0000000..03301b4
> > --- /dev/null
> > +++ b/drivers/misc/sunplus_iop.c
> > @@ -0,0 +1,438 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * The IOP driver for Sunplus SP7021
> > + *
> > + * Copyright (C) 2021 Sunplus Technology Inc.
> > + *
> > + * All Rights Reserved.
> > + */
> > +#include <linux/delay.h>
> > +#include <linux/dma-mapping.h>
> > +#include <linux/firmware.h>
> > +#include <linux/iopoll.h>
> > +#include <linux/module.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_gpio.h>
> > +
> 
> Except comments from Arnd also:
> 
> > +enum IOP_Status_e {
> > +	IOP_SUCCESS,		/* successful */
> > +	IOP_ERR_IOP_BUSY,	/* IOP is busy */
> > +};
> 
> please do not redefine true/false or ERRNO.
> 
> > +
> > +/* moon0 register offset */
> > +#define IOP_CLKEN0	0x04
> > +#define IOP_RESET0	0x54
> > +
> > +/* IOP register offset */
> > +#define IOP_CONTROL	0x00
> > +#define IOP_DATA0	0x20
> > +#define IOP_DATA1	0x24
> > +#define IOP_DATA2	0x28
> > +#define IOP_DATA3	0x2c
> > +#define IOP_DATA4	0x30
> > +#define IOP_DATA5	0x34
> > +#define IOP_DATA6	0x38
> > +#define IOP_DATA7	0x3c
> > +#define IOP_DATA8	0x40
> > +#define IOP_DATA9	0x44
> > +#define IOP_DATA10	0x48
> > +#define IOP_DATA11	0x4c
> > +#define IOP_BASE_ADR_L	0x50
> > +#define IOP_BASE_ADR_H	0x54
> > +
> > +/* PMC register offset */
> > +#define IOP_PMC_TIMER		0x00
> > +#define IOP_PMC_CTRL		0x04
> > +#define IOP_XTAL27M_PASSWORD_I	0x08
> > +#define IOP_XTAL27M_PASSWORD_II	0x0c
> > +#define IOP_XTAL32K_PASSWORD_I	0x10
> > +#define IOP_XTAL32K_PASSWORD_II	0x14
> > +#define IOP_CLK27M_PASSWORD_I	0x18
> > +#define IOP_CLK27M_PASSWORD_II	0x1c
> > +#define IOP_PMC_TIMER2		0x20
> > +
> > +#define NORMAL_CODE_MAX_SIZE 0X1000	/* Max size of normal.bin
> that can be received */
> > +#define STANDBY_CODE_MAX_SIZE 0x4000	/* Max size of standby.bin
> that can be received */
> 
> Empty line.
> 
> > +struct sp_iop {
> > +	struct device *dev;
> > +	struct mutex write_lock;	/* avoid parallel access */
> 
> This comment is useless. It is obvious that mutex is used to avoid parallel
> access, what else could it be used?
> 
> Instead, you need to describe which members/variables/parts of code are
> protected with the mutex.
> 
> > +	void __iomem *iop_regs;
> > +	void __iomem *pmc_regs;
> > +	void __iomem *moon0_regs;
> > +	int irq;
> > +	int gpio_wakeup;
> > +	unsigned char iop_normal_code[NORMAL_CODE_MAX_SIZE];
> > +	unsigned char iop_standby_code[STANDBY_CODE_MAX_SIZE];
> 
> Why not using firmware? include/linux/firmware.h? Do not reimplement
> existing solutions...
> 
> > +	resource_size_t iop_mem_start;
> > +	resource_size_t iop_mem_size;
> > +	unsigned char bin_code_mode;
> > +};
> > +
> > +static struct sp_iop *iop_poweroff;
> > +
> > +static void sp_iop_run_normal_code(struct sp_iop *iop) {
> > +	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, iop->moon0_regs + IOP_CLKEN0);
> > +
> > +	reg = readl(iop->iop_regs + IOP_CONTROL);
> > +	reg |= 0x01;
> > +	writel(reg, iop->iop_regs + IOP_CONTROL);
> > +
> > +	reg = readl(iop->iop_regs + IOP_CONTROL);
> > +	reg &= ~(0x8000);
> > +	writel(reg, iop->iop_regs + IOP_CONTROL);
> > +
> > +	reg = readl(iop->iop_regs + IOP_CONTROL);
> > +	reg |= 0x0200;// disable watchdog event reset IOP
> > +	writel(reg, iop->iop_regs + IOP_CONTROL);
> > +
> > +	reg = (iop->iop_mem_start & 0xFFFF);
> > +	writel(reg, iop->iop_regs + IOP_BASE_ADR_L);
> > +	reg	= (iop->iop_mem_start >> 16);
> > +	writel(reg, iop->iop_regs + IOP_BASE_ADR_H);
> > +
> > +	reg = readl(iop->iop_regs + IOP_CONTROL);
> > +	reg &= ~(0x01);
> > +	writel(reg, iop->iop_regs + IOP_CONTROL);
> > +	iop->bin_code_mode = 0;
> > +}
> > +
> > +static void sp_iop_run_standby_code(struct sp_iop *iop) {
> > +	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, iop->moon0_regs + IOP_CLKEN0);
> > +
> > +	reg = readl(iop->iop_regs + IOP_CONTROL);
> > +	reg |= 0x01;
> > +	writel(reg, iop->iop_regs + IOP_CONTROL);
> > +
> > +	reg = readl(iop->iop_regs + IOP_CONTROL);
> > +	reg &= ~(0x8000);
> > +	writel(reg, iop->iop_regs + IOP_CONTROL);
> > +
> > +	reg = readl(iop->iop_regs + IOP_CONTROL);
> > +	reg |= 0x0200;// disable watchdog event reset IOP
> > +	writel(reg, iop->iop_regs + IOP_CONTROL);
> > +
> > +	reg = (iop->iop_mem_start & 0xFFFF);
> > +	writel(reg, iop->iop_regs + IOP_BASE_ADR_L);
> > +	reg = (iop->iop_mem_start >> 16);
> > +	writel(reg, iop->iop_regs + IOP_BASE_ADR_H);
> > +
> > +	reg = readl(iop->iop_regs + IOP_CONTROL);
> > +	reg &= ~(0x01);
> > +	writel(reg, iop->iop_regs + IOP_CONTROL);
> > +	iop->bin_code_mode = 1;
> > +}
> > +
> > +/* 8051 informs linux kerenl. 8051 has been switched to standby.bin code.
> */
> > +#define IOP_READY	0x0004
> > +#define RISC_READY	0x0008
> > +
> > +/* System linux kernel tells 8051 which  gpio pin to wake-up through. */
> > +#define WAKEUP_PIN	0xFE02
> > +
> > +/* System linux kernel tells 8051 to execute S1 or S3 mode. */
> > +#define S1	0x5331
> > +#define S3	0x5333
> 
> Keep defines together, so beginning of file.
> 
> > +
> > +static int sp_iop_s3mode(struct device *dev, struct sp_iop *iop) {
> > +	unsigned int reg;
> > +	int ret, value;
> > +
> > +	/* PMC set */
> > +	writel(0x00010001, iop->pmc_regs + IOP_PMC_TIMER);
> > +	reg = readl(iop->pmc_regs + IOP_PMC_CTRL);
> > +	/* disable system reset PMC, enalbe power down IOP Domain, enable
> gating clock 27Mhz */
> > +	reg |= 0x23;
> > +	writel(reg, iop->pmc_regs + IOP_PMC_CTRL);
> > +
> > +	writel(0x55aa00ff, iop->pmc_regs + IOP_XTAL27M_PASSWORD_I);
> > +	writel(0x00ff55aa, iop->pmc_regs + IOP_XTAL27M_PASSWORD_II);
> > +	writel(0xaa00ff55, iop->pmc_regs + IOP_XTAL32K_PASSWORD_I);
> > +	writel(0xff55aa00, iop->pmc_regs + IOP_XTAL32K_PASSWORD_II);
> > +	writel(0xaaff0055, iop->pmc_regs + IOP_CLK27M_PASSWORD_I);
> > +	writel(0x5500aaff, iop->pmc_regs + IOP_CLK27M_PASSWORD_II);
> > +	writel(0x01000100, iop->pmc_regs + IOP_PMC_TIMER2);
> > +
> > +	/* IOP Hardware IP reset */
> > +	reg = readl(iop->moon0_regs + IOP_RESET0);
> > +	reg |= 0x10;
> > +	writel(reg, (iop->moon0_regs + IOP_RESET0));
> > +	reg &= ~(0x10);
> > +	writel(reg, (iop->moon0_regs + IOP_RESET0));
> > +
> > +	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));
> > +
> > +	writel(WAKEUP_PIN, iop->iop_regs + IOP_DATA0);
> > +	writel(iop->gpio_wakeup, iop->iop_regs + IOP_DATA1);
> > +
> > +	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA2, value,
> > +				 (value & IOP_READY) == IOP_READY, 1000, 10000);
> > +	if (ret) {
> > +		dev_err(dev, "timed out\n");
> > +		return ret;
> > +	}
> > +
> > +	reg = RISC_READY;
> > +	writel(reg, iop->iop_regs + IOP_DATA2);
> > +	reg = 0x0000;
> > +	writel(reg, iop->iop_regs + IOP_DATA5);
> > +	reg = 0x0060;
> > +	writel(reg, iop->iop_regs + IOP_DATA6);
> > +
> > +	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA7, value,
> > +				 value == 0xaaaa, 1000, 10000);
> > +	if (ret) {
> > +		dev_err(dev, "timed out\n");
> > +		return ret;
> > +	}
> > +
> > +	/* 8051 bin file call Ultra low function. */
> > +	writel(0xdd, iop->iop_regs + IOP_DATA1);
> > +	/*
> > +	 * When the execution is here, the system linux kernel
> > +	 * is about to be powered off
> > +	 * The purpose of mdelay(10): Do not let the system linux
> > +	 * kernel continue to run other programs.
> > +	 */
> > +	mdelay(10);
> > +	return 0;
> > +}
> > +
> > +static int sp_iop_s1mode(struct device *dev, struct sp_iop *iop) {
> > +	int ret, value;
> > +
> > +	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA2, value,
> > +				 (value & IOP_READY) == IOP_READY, 1000, 10000);
> > +	if (ret) {
> > +		dev_err(dev, "timed out\n");
> > +		return ret;
> > +	}
> > +
> > +	writel(RISC_READY, iop->iop_regs + IOP_DATA2);
> > +	writel(0x0000, iop->iop_regs + IOP_DATA5);
> > +	writel(0x0060, iop->iop_regs + IOP_DATA6);
> > +
> > +	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA7, value,
> > +				 value == 0xaaaa, 1000, 10000);
> 
> Hundreds of magical constants... Almost all of these should be defined or
> described.
> 
> > +	if (ret) {
> > +		dev_err(dev, "timed out\n");
> > +		return ret;
> > +	}
> > +
> > +	/* 8051 bin file call S1_mode function. */
> > +	writel(0xee, iop->iop_regs + IOP_DATA1);
> > +	/*
> > +	 * When the execution is here, the system linux kernel
> > +	 * is about to be powered off
> > +	 * The purpose of mdelay(10): Do not let the system linux
> > +	 * kernel continue to run other programs.
> > +	 */
> > +	mdelay(10);
> > +	return 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 void sp_iop_poweroff(void)
> > +{
> > +	struct sp_iop *iop = iop_poweroff;
> > +	unsigned int ret, value;
> > +
> > +	value = readl(iop->iop_regs + IOP_DATA11);
> > +	sp_iop_run_standby_code(iop);
> > +
> > +	ret = readl_poll_timeout(iop->iop_regs + IOP_DATA0, value,
> > +				 value == 0x2222, 1000, 100000);
> > +	if (ret)
> > +		dev_warn(iop->dev, "timed out\n");
> > +
> > +	if (value == S1)
> > +		sp_iop_s1mode(iop->dev, iop);
> > +	else
> > +		sp_iop_s3mode(iop->dev, iop);
> > +}
> > +
> > +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);
> > +	if (!iop) {
> > +		ret	= -ENOMEM;
> 
> Wrong spacing before '='.
> 
> > +		goto fail_kmalloc;
> > +	}
> > +	/* init */
> 
> Remove useless comments.
> 
> > +	mutex_init(&iop->write_lock);
> 
> Where are lock/unlock operations? What is this all code? This looks like
> half-baked solution...
> 
> > +	ret = sp_iop_get_resources(pdev, iop);
> > +
> > +	// Get reserve address
> 
> Keep consistent style. For comments /* is preferred. But definitely do not mix
> one with another.
> 
> This code is difficult to read.
> 
> > +	memnp = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
> > +	if (!memnp) {
> > +		dev_err(&pdev->dev, "no memory-region node\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	rc = of_address_to_resource(memnp, 0, &mem_res);
> > +	of_node_put(memnp);
> > +	if (rc) {
> > +		dev_err(&pdev->dev, "failed to translate memory-region to a
> resource\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	iop->dev = &pdev->dev;
> > +	iop->iop_mem_start = mem_res.start;
> > +	iop->iop_mem_size = resource_size(&mem_res);
> > +
> > +	/*
> > +	 * 8051 has two bin files, normal.bin and standby.bin in rootfs.
> > +	 * Normally, 8051 executes normal.bin code. Normal.bin code size can
> exceed 16K.
> > +	 * When system linux kernel is shutdown, 8051 is to execute standby.bin
> code.
> > +	 * Standby.bin code cannot exceed 16K bytes. Because 8051 Icache size is
> 16k.
> > +	 * 8051 runs with standby.bin code in the Icache before the system(linux
> kernel)
> > +	 * is poweroff.
> > +	 */
> > +	ret = sp_iop_get_normal_code(&pdev->dev, iop);
> > +	if (ret != 0) {
> > +		dev_err(&pdev->dev, "get normal code err=%d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	ret = sp_iop_get_standby_code(&pdev->dev, iop);
> > +	if (ret != 0) {
> > +		dev_err(&pdev->dev, "get standby code err=%d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	sp_iop_run_normal_code(iop);
> > +	platform_set_drvdata(pdev, iop);
> > +	iop->gpio_wakeup = of_get_named_gpio(pdev->dev.of_node,
> "iop-wakeup", 0);
> > +	iop_poweroff = iop;
> > +	pm_power_off = sp_iop_poweroff;
> 
> Blank line. Before every such return. Please, open some recent drivers and look
> at their code style.
> 
> > +	return 0;
> > +
> > +fail_kmalloc:
> > +	return ret;
> > +}
> > +
> > +static int sp_iop_remove(struct platform_device *pdev) {
> > +	pm_power_off = NULL;
> > +	return 0;
> > +}
> > +
> > +static const struct of_device_id sp_iop_of_match[] = {
> > +	{ .compatible = "sunplus,sp7021-iop" },
> > +	{ /* sentinel */ },
> > +};
> > +
> > +MODULE_DEVICE_TABLE(of, sp_iop_of_match);
> > +
> > +static struct platform_driver sp_iop_platform_driver = {
> > +	.probe		= sp_iop_platform_driver_probe,
> > +	.remove		= sp_iop_remove,
> > +	.driver = {
> > +		.name	= "sunplus,sp7021-iop",
> > +		.of_match_table = sp_iop_of_match,
> > +	}
> > +};
> > +
> > +module_platform_driver(sp_iop_platform_driver);
> > +
> > +MODULE_AUTHOR("Tony Huang <tonyhuang.sunplus@gmail.com>");
> > +MODULE_DESCRIPTION("Sunplus IOP Driver"); MODULE_LICENSE("GPL
> v2");
> 
> 
> Best regards,
> Krzysztof