Dear greg k-h:
> On Mon, Jan 10, 2022 at 02:37:54PM +0800, Tony Huang wrote:
> > IOP(8051) embedded inside SP7021 which is used as Processor for I/O
> > control, monitor RTC interrupt 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 <tonyhuang.sunplus@xxxxxxxxx>
> > ---
> > Changes in v7:
> > - Addressed comments from Greg KH.
> >
> > Documentation/ABI/testing/sysfs-platform-soc@B | 28 ++
> > MAINTAINERS | 2 +
> > drivers/misc/sunplus_iop.c | 455
> +++++++++++++++++++++++++
> > 3 files changed, 485 insertions(+)
> > create mode 100644 Documentation/ABI/testing/sysfs-platform-soc@B
> > create mode 100644 drivers/misc/sunplus_iop.c
> >
> > diff --git a/Documentation/ABI/testing/sysfs-platform-soc@B
> > b/Documentation/ABI/testing/sysfs-platform-soc@B
> > new file mode 100644
> > index 0000000..1946a6f
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/sysfs-platform-soc@B
> > @@ -0,0 +1,28 @@
> > +What: /sys/devices/platform/soc@B/9c000400.iop/sp_iop_mailbox
> > +Date: January 2022
> > +KernelVersion: 5.16
> > +Contact: Tony Huang <tonyhuang.sunplus@xxxxxxxxx>
> > +Description:
> > + Show IOP's mailbox0 register data.
> > + Format: %x
> > +
> > +What: /sys/devices/platform/soc@B/9c000400.iop/sp_iop_mode
> > +Date: January 2022
> > +KernelVersion: 5.16
> > +Contact: Tony Huang <tonyhuang.sunplus@xxxxxxxxx>
> > +Description:
> > + Read-Write.
> > +
> > + Write this file.
> > + 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.
> > + Writing of other values is invalid.
> > +
> > + Read this file.
> > + Show operation mode of IOP. "0" is normal mode. "1" is standby
> > + mode.
> > + Format: %x
> > +
> > +
> > diff --git a/MAINTAINERS b/MAINTAINERS index 6f336c9..cbc8dff 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -18245,7 +18245,9 @@ F: drivers/net/ethernet/dlink/sundance.c
> > SUNPLUS IOP DRIVER
> > M: Tony Huang <tonyhuang.sunplus@xxxxxxxxx>
> > 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 <ysato@xxxxxxxxxxxxxxxxxxxx>
> > diff --git a/drivers/misc/sunplus_iop.c b/drivers/misc/sunplus_iop.c
> > new file mode 100644 index 0000000..c27875d
> > --- /dev/null
> > +++ b/drivers/misc/sunplus_iop.c
> > @@ -0,0 +1,455 @@
> > +// 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/miscdevice.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 miscdevice 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 void sp_iop_normal_mode(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_standby_mode(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 ssize_t sp_iop_mailbox_show(struct device *dev, struct
> > +device_attribute *attr, char *buf) {
> > + struct sp_iop *iop = dev_get_drvdata(dev);
> > + unsigned int mailbox;
> > +
> > + mailbox = readl(iop->iop_regs + IOP_DATA0);
> > + return sysfs_emit(buf, "%x\n", mailbox); }
> > +
> > +static ssize_t sp_iop_mode_show(struct device *dev, struct
> > +device_attribute *attr, char *buf) {
> > + struct sp_iop *iop = dev_get_drvdata(dev);
> > +
> > + return sysfs_emit(buf, "%x\n", iop->bin_code_mode); }
> > +
> > +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);
> > +
> > + if (sysfs_streq(buf, "0"))
> > + sp_iop_normal_mode(iop);
> > + else if (sysfs_streq(buf, "1"))
> > + sp_iop_standby_mode(iop);
> > + else
> > + return -EINVAL;
> > + return count;
> > +}
> > +
> > +static DEVICE_ATTR_RO(sp_iop_mailbox); static
> > +DEVICE_ATTR_RW(sp_iop_mode);
>
> Please do not manually create the sysfs files. You race with userspace and
> loose. Use the default_groups pointer of the platform driver and then the
> driver core will handle that all for you automatically.
OK, I will use the default_groups pointer of the platform driver.
