[PATCH v5 22/25] firmware: xilinx: Add sysfs interface

From: Jolly Shah
Date: Fri Apr 24 2020 - 16:59:02 EST


From: Rajan Vaja <rajan.vaja@xxxxxxxxxx>

Add firmware-ggs sysfs interface which provides read/write
interface to global storage registers.

Signed-off-by: Rajan Vaja <rajan.vaja@xxxxxxxxxx>
Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
Signed-off-by: Tejas Patel <tejas.patel@xxxxxxxxxx>
Signed-off-by: Jolly Shah <jolly.shah@xxxxxxxxxx>
---
.../ABI/stable/sysfs-driver-firmware-zynqmp | 50 ++++++
drivers/firmware/xilinx/zynqmp.c | 167 ++++++++++++++++++++-
include/linux/firmware/xlnx-zynqmp.h | 2 +
3 files changed, 218 insertions(+), 1 deletion(-)
create mode 100644 Documentation/ABI/stable/sysfs-driver-firmware-zynqmp

diff --git a/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp b/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp
new file mode 100644
index 0000000..2e3aebd
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp
@@ -0,0 +1,50 @@
+What: /sys/devices/platform/firmware\:zynqmp-firmware/ggs*
+Date: March 2020
+KernelVersion: 5.6
+Contact: "Jolly Shah" <jollys@xxxxxxxxxx>
+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/devices/platform/firmware\:zynqmp-firmware/ggs0
+ # echo <value> > /sys/devices/platform/firmware\:zynqmp-firmware/ggs0
+
+ Example:
+ # cat /sys/devices/platform/firmware\:zynqmp-firmware/ggs0
+ # echo 0x1234ABCD > /sys/devices/platform/firmware\:zynqmp-firmware/ggs0
+
+Users: Xilinx
+
+What: /sys/devices/platform/firmware\:zynqmp-firmware/pggs*
+Date: March 2020
+KernelVersion: 5.6
+Contact: "Jolly Shah" <jollys@xxxxxxxxxx>
+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/devices/platform/firmware\:zynqmp-firmware/pggs0
+ # echo <value> > /sys/devices/platform/firmware\:zynqmp-firmware/pggs0
+
+ Example:
+ # cat /sys/devices/platform/firmware\:zynqmp-firmware/pggs0
+ # echo 0x1234ABCD > /sys/devices/platform/firmware\:zynqmp-firmware/pggs0
+
+Users: Xilinx
diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c
index 3518456..2fe4f57 100644
--- a/drivers/firmware/xilinx/zynqmp.c
+++ b/drivers/firmware/xilinx/zynqmp.c
@@ -2,7 +2,7 @@
/*
* Xilinx Zynq MPSoC Firmware layer
*
- * Copyright (C) 2014-2018 Xilinx, Inc.
+ * Copyright (C) 2014-2020 Xilinx, Inc.
*
* Michal Simek <michal.simek@xxxxxxxxxx>
* Davorin Mista <davorin.mista@xxxxxxxxxx>
@@ -875,6 +875,170 @@ int zynqmp_pm_aes_engine(const u64 address, u32 *out)
}
EXPORT_SYMBOL_GPL(zynqmp_pm_aes_engine);

+static ssize_t ggs_show(struct device *device,
+ struct device_attribute *attr,
+ char *buf,
+ u32 reg)
+{
+ int ret;
+ u32 ret_payload[PAYLOAD_ARG_CNT];
+
+ ret = zynqmp_pm_read_ggs(reg, ret_payload);
+ if (ret)
+ return ret;
+
+ return sprintf(buf, "0x%x\n", ret_payload[1]);
+}
+
+static ssize_t ggs_store(struct device *device,
+ struct device_attribute *attr,
+ const char *buf, size_t count,
+ u32 reg)
+{
+ long value;
+ int ret;
+
+ if (reg >= GSS_NUM_REGS)
+ return -EINVAL;
+
+ ret = kstrtol(buf, 16, &value);
+ if (ret) {
+ count = -EFAULT;
+ goto err;
+ }
+
+ ret = zynqmp_pm_write_ggs(reg, value);
+ if (ret)
+ count = -EFAULT;
+
+err:
+ return count;
+}
+
+/* GGS register show functions */
+#define GGS0_SHOW(N) \
+ ssize_t ggs##N##_show(struct device *device, \
+ struct device_attribute *attr, \
+ char *buf) \
+ { \
+ return ggs_show(device, 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 device *device, \
+ struct device_attribute *attr, \
+ const char *buf, \
+ size_t count) \
+ { \
+ return ggs_store(device, attr, buf, count, N); \
+ }
+
+static GGS0_STORE(0);
+static GGS0_STORE(1);
+static GGS0_STORE(2);
+static GGS0_STORE(3);
+
+static ssize_t pggs_show(struct device *device,
+ struct device_attribute *attr,
+ char *buf,
+ u32 reg)
+{
+ int ret;
+ u32 ret_payload[PAYLOAD_ARG_CNT];
+
+ ret = zynqmp_pm_read_pggs(reg, ret_payload);
+ if (ret)
+ return ret;
+
+ return sprintf(buf, "0x%x\n", ret_payload[1]);
+}
+
+static ssize_t pggs_store(struct device *device,
+ struct device_attribute *attr,
+ const char *buf, size_t count,
+ u32 reg)
+{
+ long value;
+ int ret;
+
+ if (reg >= GSS_NUM_REGS)
+ return -EINVAL;
+
+ ret = kstrtol(buf, 16, &value);
+ if (ret) {
+ count = -EFAULT;
+ goto err;
+ }
+
+ ret = zynqmp_pm_write_pggs(reg, value);
+ if (ret)
+ count = -EFAULT;
+
+err:
+ return count;
+}
+
+#define PGGS0_SHOW(N) \
+ ssize_t pggs##N##_show(struct device *device, \
+ struct device_attribute *attr, \
+ char *buf) \
+ { \
+ return pggs_show(device, attr, buf, N); \
+ }
+
+#define PGGS0_STORE(N) \
+ ssize_t pggs##N##_store(struct device *device, \
+ struct device_attribute *attr, \
+ const char *buf, \
+ size_t count) \
+ { \
+ return pggs_store(device, 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 DEVICE_ATTR_RW(ggs0);
+static DEVICE_ATTR_RW(ggs1);
+static DEVICE_ATTR_RW(ggs2);
+static DEVICE_ATTR_RW(ggs3);
+
+/* PGGS register attributes */
+static DEVICE_ATTR_RW(pggs0);
+static DEVICE_ATTR_RW(pggs1);
+static DEVICE_ATTR_RW(pggs2);
+static DEVICE_ATTR_RW(pggs3);
+
+static struct attribute *zynqmp_firmware_attrs[] = {
+ &dev_attr_ggs0.attr,
+ &dev_attr_ggs1.attr,
+ &dev_attr_ggs2.attr,
+ &dev_attr_ggs3.attr,
+ &dev_attr_pggs0.attr,
+ &dev_attr_pggs1.attr,
+ &dev_attr_pggs2.attr,
+ &dev_attr_pggs3.attr,
+ NULL,
+};
+
+ATTRIBUTE_GROUPS(zynqmp_firmware);
+
static int zynqmp_firmware_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -952,6 +1116,7 @@ static struct platform_driver zynqmp_firmware_driver = {
.driver = {
.name = "zynqmp_firmware",
.of_match_table = zynqmp_firmware_of_match,
+ .dev_groups = zynqmp_firmware_groups,
},
.probe = zynqmp_firmware_probe,
.remove = zynqmp_firmware_remove,
diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
index e23251d..c1356e9 100644
--- a/include/linux/firmware/xlnx-zynqmp.h
+++ b/include/linux/firmware/xlnx-zynqmp.h
@@ -42,6 +42,8 @@

#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
--
2.7.4