Re: [PATCH 2/5] firmware: xilinx: Add sysfs interface

Michal Simek
2019-12-18T14:21:44Z

On 05. 12. 19 0:29, Jolly Shah wrote:
> From: Rajan Vaja <rajan.vaja@xilinx.com>
>
> Add Firmware-ggs sysfs interface which provides read/write
> interface to global storage registers.
>
> Signed-off-by: Michal Simek <michal.simek@xilinx.com>
> Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
> Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
> ---
> Documentation/ABI/stable/sysfs-firmware-zynqmp | 50 +++++
> drivers/firmware/xilinx/Makefile | 2 +-
> drivers/firmware/xilinx/zynqmp-ggs.c | 289 +++++++++++++++++++++++++
> drivers/firmware/xilinx/zynqmp.c | 12 +
> include/linux/firmware/xlnx-zynqmp.h | 10 +
> 5 files changed, 362 insertions(+), 1 deletion(-)
> create mode 100644 Documentation/ABI/stable/sysfs-firmware-zynqmp
> create mode 100644 drivers/firmware/xilinx/zynqmp-ggs.c
>
> diff --git a/Documentation/ABI/stable/sysfs-firmware-zynqmp b/Documentation/ABI/stable/sysfs-firmware-zynqmp
> new file mode 100644
> index 0000000..0a75812
> --- /dev/null
> +++ b/Documentation/ABI/stable/sysfs-firmware-zynqmp
> @@ -0,0 +1,50 @@
> +What: /sys/firmware/zynqmp/ggs*
> +Date: January 2018
> +KernelVersion: 4.15.0

looks old.

> +Contact: "Jolly Shah" <jollys@xilinx.com>
> +Description:
> + Read/Write PMU global general storage register value,
> + GLOBAL_GEN_STORAGE{0:3}.
> + Global general storage register that can be used
> + by system to pass information between masters.
> +
> + The register is reset during system or power-on
> + resets. Three registers are used by the FSBL and
> + other Xilinx software products: GLOBAL_GEN_STORAGE{4:6}.
> +
> + Usage:
> + # cat /sys/firmware/zynqmp/ggs0
> + # echo <mask> <value> > /sys/firmware/zynqmp/ggs0
> +
> + Example:
> + # cat /sys/firmware/zynqmp/ggs0
> + # echo 0xFFFFFFFF 0x1234ABCD > /sys/firmware/zynqmp/ggs0
> +
> +Users: Xilinx
> +
> +What: /sys/firmware/zynqmp/pggs*
> +Date: January 2018
> +KernelVersion: 4.15.0

ditto.

> +Contact: "Jolly Shah" <jollys@xilinx.com>
> +Description:
> + Read/Write PMU persistent global general storage register
> + value, PERS_GLOB_GEN_STORAGE{0:3}.
> + Persistent global general storage register that
> + can be used by system to pass information between
> + masters.
> +
> + This register is only reset by the power-on reset
> + and maintains its value through a system reset.
> + Four registers are used by the FSBL and other Xilinx
> + software products: PERS_GLOB_GEN_STORAGE{4:7}.
> + Register is reset only by a POR reset.
> +
> + Usage:
> + # cat /sys/firmware/zynqmp/pggs0
> + # echo <mask> <value> > /sys/firmware/zynqmp/pggs0
> +
> + Example:
> + # cat /sys/firmware/zynqmp/pggs0
> + # echo 0xFFFFFFFF 0x1234ABCD > /sys/firmware/zynqmp/pggs0
> +
> +Users: Xilinx
> diff --git a/drivers/firmware/xilinx/Makefile b/drivers/firmware/xilinx/Makefile
> index 875a537..1e8643c 100644
> --- a/drivers/firmware/xilinx/Makefile
> +++ b/drivers/firmware/xilinx/Makefile
> @@ -1,5 +1,5 @@
> # SPDX-License-Identifier: GPL-2.0
> # Makefile for Xilinx firmwares
>
> -obj-$(CONFIG_ZYNQMP_FIRMWARE) += zynqmp.o
> +obj-$(CONFIG_ZYNQMP_FIRMWARE) += zynqmp.o zynqmp-ggs.o
> obj-$(CONFIG_ZYNQMP_FIRMWARE_DEBUG) += zynqmp-debug.o
> diff --git a/drivers/firmware/xilinx/zynqmp-ggs.c b/drivers/firmware/xilinx/zynqmp-ggs.c
> new file mode 100644
> index 0000000..42179ad
> --- /dev/null
> +++ b/drivers/firmware/xilinx/zynqmp-ggs.c
> @@ -0,0 +1,289 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Xilinx Zynq MPSoC Firmware layer
> + *
> + * Copyright (C) 2014-2018 Xilinx, Inc.
> + *
> + * Jolly Shah <jollys@xilinx.com>
> + * Rajan Vaja <rajanv@xilinx.com>
> + */
> +
> +#include <linux/compiler.h>
> +#include <linux/of.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/uaccess.h>
> +#include <linux/slab.h>
> +#include <linux/firmware/xlnx-zynqmp.h>
> +
> +static ssize_t read_register(char *buf, u32 ioctl_id, u32 reg)
> +{
> + int ret;
> + u32 ret_payload[PAYLOAD_ARG_CNT];
> + const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
> +
> + if (!eemi_ops->ioctl)
> + return -EFAULT;
> +
> + ret = eemi_ops->ioctl(0, ioctl_id, reg, 0, ret_payload);
> + if (ret)
> + return ret;
> +
> + return sprintf(buf, "0x%x\n", ret_payload[1]);
> +}
> +
> +static ssize_t write_register(const char *buf, size_t count, u32 read_ioctl,
> + u32 write_ioctl, u32 reg)
> +{
> + char *kern_buff, *inbuf, *tok;
> + long mask, value;
> + int ret;
> + u32 ret_payload[PAYLOAD_ARG_CNT];
> + const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
> +
> + if (!eemi_ops->ioctl)
> + return -EFAULT;
> +
> + kern_buff = kzalloc(count, GFP_KERNEL);
> + if (!kern_buff)
> + return -ENOMEM;
> +
> + ret = strlcpy(kern_buff, buf, count);
> + if (ret < 0) {
> + ret = -EFAULT;
> + goto err;
> + }
> +
> + inbuf = kern_buff;
> +
> + /* Read the write mask */
> + tok = strsep(&inbuf, " ");
> + if (!tok) {
> + ret = -EFAULT;
> + goto err;
> + }
> +
> + ret = kstrtol(tok, 16, &mask);
> + if (ret) {
> + ret = -EFAULT;
> + goto err;
> + }
> +
> + /* Read the write value */
> + tok = strsep(&inbuf, " ");
> + if (!tok) {
> + ret = -EFAULT;
> + goto err;
> + }
> +
> + ret = kstrtol(tok, 16, &value);
> + if (ret) {
> + ret = -EFAULT;
> + goto err;
> + }
> +
> + ret = eemi_ops->ioctl(0, read_ioctl, reg, 0, ret_payload);
> + if (ret) {
> + ret = -EFAULT;
> + goto err;
> + }
> + ret_payload[1] &= ~mask;
> + value &= mask;
> + value |= ret_payload[1];
> +
> + ret = eemi_ops->ioctl(0, write_ioctl, reg, value, NULL);
> + if (ret)
> + ret = -EFAULT;
> +
> +err:
> + kfree(kern_buff);
> + if (ret)
> + return ret;
> +
> + return count;
> +}
> +
> +/**
> + * ggs_show - Show global general storage (ggs) sysfs attribute
> + * @kobj: Kobject structure
> + * @attr: Kobject attribute structure
> + * @buf: Requested available shutdown_scope attributes string
> + * @reg: Register number
> + *
> + * Return:Number of bytes printed into the buffer.
> + *
> + * Helper function for viewing a ggs register value.
> + *
> + * User-space interface for viewing the content of the ggs0 register.
> + * cat /sys/firmware/zynqmp/ggs0
> + */
> +static ssize_t ggs_show(struct kobject *kobj,
> + struct kobj_attribute *attr,
> + char *buf,
> + u32 reg)
> +{
> + return read_register(buf, IOCTL_READ_GGS, reg);
> +}
> +
> +/**
> + * ggs_store - Store global general storage (ggs) sysfs attribute
> + * @kobj: Kobject structure
> + * @attr: Kobject attribute structure
> + * @buf: User entered shutdown_scope attribute string
> + * @count: Size of buf
> + * @reg: Register number
> + *
> + * Return: count argument if request succeeds, the corresponding
> + * error code otherwise
> + *
> + * Helper function for storing a ggs register value.
> + *
> + * For example, the user-space interface for storing a value to the
> + * ggs0 register:
> + * echo 0xFFFFFFFF 0x1234ABCD > /sys/firmware/zynqmp/ggs0
> + */
> +static ssize_t ggs_store(struct kobject *kobj,
> + struct kobj_attribute *attr,
> + const char *buf,
> + size_t count,
> + u32 reg)
> +{
> + if (!kobj || !attr || !buf || !count || reg >= GSS_NUM_REGS)
> + return -EINVAL;
> +
> + return write_register(buf, count, IOCTL_READ_GGS, IOCTL_WRITE_GGS, reg);
> +}
> +
> +/* GGS register show functions */
> +#define GGS0_SHOW(N) \
> + ssize_t ggs##N##_show(struct kobject *kobj, \
> + struct kobj_attribute *attr, \
> + char *buf) \
> + { \
> + return ggs_show(kobj, attr, buf, N); \
> + }
> +
> +static GGS0_SHOW(0);
> +static GGS0_SHOW(1);
> +static GGS0_SHOW(2);
> +static GGS0_SHOW(3);
> +
> +/* GGS register store function */
> +#define GGS0_STORE(N) \
> + ssize_t ggs##N##_store(struct kobject *kobj, \
> + struct kobj_attribute *attr, \
> + const char *buf, \
> + size_t count) \
> + { \
> + return ggs_store(kobj, attr, buf, count, N); \
> + }
> +
> +static GGS0_STORE(0);
> +static GGS0_STORE(1);
> +static GGS0_STORE(2);
> +static GGS0_STORE(3);
> +
> +/**
> + * pggs_show - Show persistent global general storage (pggs) sysfs attribute
> + * @kobj: Kobject structure
> + * @attr: Kobject attribute structure
> + * @buf: Requested available shutdown_scope attributes string
> + * @reg: Register number
> + *
> + * Return:Number of bytes printed into the buffer.
> + *
> + * Helper function for viewing a pggs register value.
> + */
> +static ssize_t pggs_show(struct kobject *kobj,
> + struct kobj_attribute *attr,
> + char *buf,
> + u32 reg)
> +{
> + return read_register(buf, IOCTL_READ_PGGS, reg);
> +}
> +
> +/**
> + * pggs_store - Store persistent global general storage (pggs) sysfs attribute
> + * @kobj: Kobject structure
> + * @attr: Kobject attribute structure
> + * @buf: User entered shutdown_scope attribute string
> + * @count: Size of buf
> + * @reg: Register number
> + *
> + * Return: count argument if request succeeds, the corresponding
> + * error code otherwise
> + *
> + * Helper function for storing a pggs register value.
> + */
> +static ssize_t pggs_store(struct kobject *kobj,
> + struct kobj_attribute *attr,
> + const char *buf,
> + size_t count,
> + u32 reg)
> +{
> + return write_register(buf, count, IOCTL_READ_PGGS,
> + IOCTL_WRITE_PGGS, reg);
> +}
> +
> +#define PGGS0_SHOW(N) \
> + ssize_t pggs##N##_show(struct kobject *kobj, \
> + struct kobj_attribute *attr, \
> + char *buf) \
> + { \
> + return pggs_show(kobj, attr, buf, N); \
> + }
> +
> +#define PGGS0_STORE(N) \
> + ssize_t pggs##N##_store(struct kobject *kobj, \
> + struct kobj_attribute *attr, \
> + const char *buf, \
> + size_t count) \
> + { \
> + return pggs_store(kobj, attr, buf, count, N); \
> + }
> +
> +/* PGGS register show functions */
> +static PGGS0_SHOW(0);
> +static PGGS0_SHOW(1);
> +static PGGS0_SHOW(2);
> +static PGGS0_SHOW(3);
> +
> +/* PGGS register store functions */
> +static PGGS0_STORE(0);
> +static PGGS0_STORE(1);
> +static PGGS0_STORE(2);
> +static PGGS0_STORE(3);
> +
> +/* GGS register attributes */
> +static struct kobj_attribute zynqmp_attr_ggs0 = __ATTR_RW(ggs0);
> +static struct kobj_attribute zynqmp_attr_ggs1 = __ATTR_RW(ggs1);
> +static struct kobj_attribute zynqmp_attr_ggs2 = __ATTR_RW(ggs2);
> +static struct kobj_attribute zynqmp_attr_ggs3 = __ATTR_RW(ggs3);
> +
> +/* PGGS register attributes */
> +static struct kobj_attribute zynqmp_attr_pggs0 = __ATTR_RW(pggs0);
> +static struct kobj_attribute zynqmp_attr_pggs1 = __ATTR_RW(pggs1);
> +static struct kobj_attribute zynqmp_attr_pggs2 = __ATTR_RW(pggs2);
> +static struct kobj_attribute zynqmp_attr_pggs3 = __ATTR_RW(pggs3);
> +
> +static struct attribute *attrs[] = {
> + &zynqmp_attr_ggs0.attr,
> + &zynqmp_attr_ggs1.attr,
> + &zynqmp_attr_ggs2.attr,
> + &zynqmp_attr_ggs3.attr,
> + &zynqmp_attr_pggs0.attr,
> + &zynqmp_attr_pggs1.attr,
> + &zynqmp_attr_pggs2.attr,
> + &zynqmp_attr_pggs3.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group attr_group = {
> + .attrs = attrs,
> + NULL,
> +};

the same as was in 1/5

> +
> +int zynqmp_pm_ggs_init(struct kobject *parent_kobj)
> +{
> + return sysfs_create_group(parent_kobj, &attr_group);
> +}
> diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c
> index 56431ad..9836174 100644
> --- a/drivers/firmware/xilinx/zynqmp.c
> +++ b/drivers/firmware/xilinx/zynqmp.c
> @@ -475,6 +475,10 @@ static inline int zynqmp_is_valid_ioctl(u32 ioctl_id)
> case IOCTL_GET_PLL_FRAC_MODE:
> case IOCTL_SET_PLL_FRAC_DATA:
> case IOCTL_GET_PLL_FRAC_DATA:
> + case IOCTL_WRITE_GGS:
> + case IOCTL_READ_GGS:
> + case IOCTL_WRITE_PGGS:
> + case IOCTL_READ_PGGS:
> return 1;
> default:
> return 0;
> @@ -876,8 +880,16 @@ static int zynqmp_pm_sysfs_init(void)
> if (ret) {
> pr_err("%s() sysfs creation fail with error %d\n",
> __func__, ret);
> + goto err;
> }
>
> + ret = zynqmp_pm_ggs_init(zynqmp_kobj);
> + if (ret) {
> + pr_err("%s() GGS init fail with error %d\n",
> + __func__, ret);
> + goto err;
> + }
> +err:
> return ret;
> }
>
> diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
> index 55561d0..bf6e9db 100644
> --- a/include/linux/firmware/xlnx-zynqmp.h
> +++ b/include/linux/firmware/xlnx-zynqmp.h
> @@ -13,6 +13,8 @@
> #ifndef __FIRMWARE_ZYNQMP_H__
> #define __FIRMWARE_ZYNQMP_H__
>
> +#include <linux/device.h>
> +
> #define ZYNQMP_PM_VERSION_MAJOR 1
> #define ZYNQMP_PM_VERSION_MINOR 0
>
> @@ -42,6 +44,8 @@
>
> #define ZYNQMP_PM_MAX_QOS 100U
>
> +#define GSS_NUM_REGS (4)
> +
> /* Node capabilities */
> #define ZYNQMP_PM_CAPABILITY_ACCESS 0x1U
> #define ZYNQMP_PM_CAPABILITY_CONTEXT 0x2U
> @@ -98,6 +102,10 @@ enum pm_ioctl_id {
> IOCTL_GET_PLL_FRAC_MODE,
> IOCTL_SET_PLL_FRAC_DATA,
> IOCTL_GET_PLL_FRAC_DATA,
> + IOCTL_WRITE_GGS,
> + IOCTL_READ_GGS,
> + IOCTL_WRITE_PGGS,
> + IOCTL_READ_PGGS,
> };
>
> enum pm_query_id {
> @@ -319,6 +327,8 @@ struct zynqmp_eemi_ops {
> int zynqmp_pm_invoke_fn(u32 pm_api_id, u32 arg0, u32 arg1,
> u32 arg2, u32 arg3, u32 *ret_payload);
>
> +int zynqmp_pm_ggs_init(struct kobject *parent_kobj);
> +
> #if IS_REACHABLE(CONFIG_ARCH_ZYNQMP)
> const struct zynqmp_eemi_ops *zynqmp_pm_get_eemi_ops(void);
> #else
>

M