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

Jolly Shah
2019-12-04T23:29:46Z

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
+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
+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,
+};
+
+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
--
2.7.4