Add a simple sysfs interface to the generic pinctrl framework
for configuring pins for output disable operation.
/sys/class/pinctrl/
`-- output-disable/
|-- configure (w/o) ask the kernel to configure a pin group
for output disable operation.
echo "<group-name function-name 0 1>" > configure
The existing "pinmux-functions" debugfs file lists the pin functions
registered for the pin controller. For example:
function 0: usb0, groups = [ usb0 ]
function 1: usb1, groups = [ usb1 ]
function 2: gpt4-pins, groups = [ gpt4-pins ]
function 3: scif0, groups = [ scif0 ]
function 4: scif2, groups = [ scif2 ]
function 5: spi1, groups = [ spi1 ]
To configure gpt4-pins for output disable activation by user:
echo "gpt4-pins gpt4-pins 0 1" > configure
Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
---
v6:
* New patch
Ref:
https://lore.kernel.org/linux-renesas-soc/OS0PR01MB5922F5494D3C0862E15F3F8486B39@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/T/#t
---
Documentation/ABI/testing/sysfs-class-pinctrl | 32 ++++
drivers/pinctrl/Kconfig | 4 +
drivers/pinctrl/Makefile | 1 +
drivers/pinctrl/core.c | 3 +
drivers/pinctrl/output-disable.c | 148 ++++++++++++++++++
drivers/pinctrl/output-disable.h | 32 ++++
6 files changed, 220 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-class-pinctrl
create mode 100644 drivers/pinctrl/output-disable.c
create mode 100644 drivers/pinctrl/output-disable.h
diff --git a/Documentation/ABI/testing/sysfs-class-pinctrl b/Documentation/ABI/testing/sysfs-class-pinctrl
new file mode 100644
index 000000000000..cdf47ea77c32
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-pinctrl
@@ -0,0 +1,32 @@
+What: /sys/class/pinctrl
+Date: March 2023
+KernelVersion: 6.4
+Contact: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
+Description:
+ The pinctrl class sub-directory belongs to the Generic pincontrol
+ Framework and provides a sysfs interface for using pincontrol
+ configurations.
+
+What: /sys/class/pinctrl/output-disable
+Date: March 2023
+KernelVersion: 6.4
+Contact: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
+Description:
+ A /sys/class/pinctrl/output-disable directory is created for
+ pin output disable function.
+
+What: /sys/class/pinctrl/output-disable/configure
+Date: March 2023
+KernelVersion: 6.4
+Contact: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
+Description:
+ The configuration for pin output disable IP.
+
+ Write the following string to configure the pin output disable:
+
+ - "fname gname conf conf_val"
+
+ fname is function name,
+ gname is group name,
+ conf is configuration
+ conf_val is 0 or 1, to disable/enable the above conf.
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index dcb53c4a9584..3553d76c3577 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -21,6 +21,10 @@ config GENERIC_PINMUX_FUNCTIONS
config PINCONF
bool "Support pin configuration controllers" if COMPILE_TEST
+config PIN_OUTPUT_DISABLE
+ bool
+ default y if SYSFS
+
config GENERIC_PINCONF
bool
select PINCONF
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index d5939840bb2a..e923adaa2b9c 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -6,6 +6,7 @@ subdir-ccflags-$(CONFIG_DEBUG_PINCTRL) += -DDEBUG
obj-y += core.o pinctrl-utils.o
obj-$(CONFIG_PINMUX) += pinmux.o
obj-$(CONFIG_PINCONF) += pinconf.o
+obj-$(CONFIG_PIN_OUTPUT_DISABLE) += output-disable.o
obj-$(CONFIG_GENERIC_PINCONF) += pinconf-generic.o
obj-$(CONFIG_OF) += devicetree.o
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 2ba222026db4..3fce50786754 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -36,6 +36,7 @@
#include "core.h"
#include "devicetree.h"
+#include "output-disable.h"
#include "pinconf.h"
#include "pinmux.h"
@@ -2171,6 +2172,7 @@ int pinctrl_enable(struct pinctrl_dev *pctldev)
mutex_unlock(&pinctrldev_list_mutex);
pinctrl_init_device_debugfs(pctldev);
+ output_disable_init_device_sysfs(pctldev);
return 0;
}
@@ -2252,6 +2254,7 @@ void pinctrl_unregister(struct pinctrl_dev *pctldev)
mutex_lock(&pctldev->mutex);
pinctrl_remove_device_debugfs(pctldev);
+ output_disable_remove_device_sysfs(pctldev);
mutex_unlock(&pctldev->mutex);
if (!IS_ERR_OR_NULL(pctldev->p))
diff --git a/drivers/pinctrl/output-disable.c b/drivers/pinctrl/output-disable.c
new file mode 100644
index 000000000000..fb233b10b7df
--- /dev/null
+++ b/drivers/pinctrl/output-disable.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic pin output-disable sysfs interface for pinctrl
+ * Copyright (C) 2023 <biju.das.jz@xxxxxxxxxxxxxx>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include <linux/pinctrl/consumer.h>
+#include <linux/pinctrl/output-disable.h>
+#include <linux/pinctrl/pinctrl.h>
+
+#include "core.h"
+#include "output-disable.h"
+
+#define OUTPUT_DISABLE_BUF_MAX 128
+
+static int output_disable_get_vars(char *src, char **dst)
+{
+ char *result = (char *)dst;
+
+ /* find a separator which is a spacelike character */
+ for (result = src; !isspace(*result); result++) {
+ if (*result == '\0')
+ return -EINVAL;
+ }
+ *result = '\0';
+
+ /* drop extra spaces between function and group names */
+ result = skip_spaces(result + 1);
+ if (*result == '\0')
+ return -EINVAL;
+
+ *dst = result;
+
+ return 0;
+}
+
+static ssize_t configure_store(struct device *parent,
+ struct device_attribute *attr,
+ const char *src_buf,
+ size_t len)
+{
+ struct pinctrl_dev *pctldev = dev_get_drvdata(parent);
+ const struct pin_output_disable_ops *poutdisops = pctldev->desc->poutdisops;
+ char *buf, *gname, *fname, *conf, *conf_val;
+ int config, config_val;
+ struct device *dev;
+ int ret;
+
+ if (len > OUTPUT_DISABLE_BUF_MAX)
+ return -ENOMEM;
+
+ buf = kzalloc(OUTPUT_DISABLE_BUF_MAX, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ memcpy(buf, src_buf, len);
+ buf[len - 1] = '\0';
+
+ /* remove leading and trailing spaces of input buffer */
+ gname = strstrip(buf);
+ if (*gname == '\0') {
+ ret = -EINVAL;
+ goto exit_free_buf;
+ }
+
+ ret = output_disable_get_vars(gname, &fname);
+ if (ret < 0)
+ goto exit_free_buf;
+
+ ret = output_disable_get_vars(fname, &conf);
+ if (ret < 0)
+ goto exit_free_buf;
+
+ ret = output_disable_get_vars(conf, &conf_val);
+ if (ret < 0)
+ goto exit_free_buf;
+
+ ret = kstrtoint(conf, 0, &config);
+ if (ret)
+ goto exit_free_buf;
+
+ ret = kstrtoint(conf_val, 0, &config_val);
+ if (ret)
+ goto exit_free_buf;
+
+ dev = pinctrl_get_device(fname, gname);
+ if (IS_ERR(dev)) {
+ dev_err(pctldev->dev, "invalid function %s in map table\n", fname);
+ goto exit_free_buf;
+ }
+
+ if (poutdisops)
+ poutdisops->pin_output_disable_config_set(pctldev, dev,
+ fname, gname,
+ config, config_val);
+
+exit_free_buf:
+ kfree(buf);
+
+ return ret ? : len;
+}
+static DEVICE_ATTR_WO(configure);
+
+static struct attribute *pinctrl_attrs[] = {
+ &dev_attr_configure.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(pinctrl);
+
+static struct class pinctrl_class = {
+ .name = "pinctrl",
+ .owner = THIS_MODULE,
+ .dev_groups = pinctrl_groups,
+};
+
+void output_disable_init_device_sysfs(struct pinctrl_dev *pctldev)
+{
+ struct device *parent;
+
+ parent = device_create(&pinctrl_class, pctldev->dev, MKDEV(0, 0),
+ pctldev, "output-disable");
+ if (IS_ERR(parent))
+ dev_err(pctldev->dev, "device_create failed for pinctrl sysfs\n");
+}
+
+void output_disable_remove_device_sysfs(struct pinctrl_dev *pctldev)
+{
+ device_destroy(&pinctrl_class, MKDEV(0, 0));
+}
+
+static int __init pinctrl_sysfs_init(void)
+{
+ return class_register(&pinctrl_class);
+}
+subsys_initcall(pinctrl_sysfs_init);
+
+static void __exit pinctrl_sysfs_exit(void)
+{
+ class_unregister(&pinctrl_class);
+}
+module_exit(pinctrl_sysfs_exit);
diff --git a/drivers/pinctrl/output-disable.h b/drivers/pinctrl/output-disable.h
new file mode 100644
index 000000000000..f933965599d2
--- /dev/null
+++ b/drivers/pinctrl/output-disable.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Internal interface between the core pin control system and the
+ * ouput-disable portions
+ *
+ * Copyright (C) 2023 Renesas Electronics Corporation
+ * Based on bits of pinmux.c
+ *
+ * Author: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
+ */
+
+#include <linux/types.h>
+
+struct dentry;
+struct seq_file;
+
+struct pinctrl_dev;
+
+#ifdef CONFIG_PIN_OUTPUT_DISABLE
+void output_disable_init_device_sysfs(struct pinctrl_dev *pctldev);
+void output_disable_remove_device_sysfs(struct pinctrl_dev *pctldev);
+
+#else
+static inline void output_disable_init_device_sysfs(struct pinctrl_dev *pctldev)
+{
+}
+
+static inline void output_disable_remove_device_sysfs(struct pinctrl_dev *pctldev)
+{
+}
+
+#endif
--
2.25.1
