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Message-Id: <20210216224455.1504008-3-drew@beagleboard.org>
Date: Tue, 16 Feb 2021 14:44:54 -0800
From: Drew Fustini <drew@...gleboard.org>
To: Linus Walleij <linus.walleij@...aro.org>,
linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
Tony Lindgren <tony@...mide.com>,
Andy Shevchenko <andy.shevchenko@...il.com>,
Alexandre Belloni <alexandre.belloni@...tlin.com>,
Geert Uytterhoeven <geert@...ux-m68k.org>,
Pantelis Antoniou <pantelis.antoniou@...sulko.com>,
Jason Kridner <jkridner@...gleboard.org>,
Robert Nelson <robertcnelson@...gleboard.org>,
Joe Perches <joe@...ches.com>,
Dan Carpenter <dan.carpenter@...cle.com>,
Jonathan Corbet <corbet@....net>, linux-doc@...r.kernel.org
Cc: Drew Fustini <drew@...gleboard.org>
Subject: [PATCH v6 2/3] pinctrl: pinmux: Add pinmux-select debugfs file
Add "pinmux-select" to debugfs which will activate a function and group:
echo "<function-name group-name>" > pinmux-select
The write operation pinmux_select() handles this by checking that the
names map to valid selectors and then calling ops->set_mux().
The existing "pinmux-functions" debugfs file lists the pin functions
registered for the pin controller. For example:
function: pinmux-uart0, groups = [ pinmux-uart0-pins ]
function: pinmux-mmc0, groups = [ pinmux-mmc0-pins ]
function: pinmux-mmc1, groups = [ pinmux-mmc1-pins ]
function: pinmux-i2c0, groups = [ pinmux-i2c0-pins ]
function: pinmux-i2c1, groups = [ pinmux-i2c1-pins ]
function: pinmux-spi1, groups = [ pinmux-spi1-pins ]
To activate function pinmux-i2c1 and group pinmux-i2c1-pins:
echo "pinmux-i2c1 pinmux-i2c1-pins" > pinmux-select
Signed-off-by: Drew Fustini <drew@...gleboard.org>
---
drivers/pinctrl/pinmux.c | 102 +++++++++++++++++++++++++++++++++++++++
1 file changed, 102 insertions(+)
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
index c651b2db0925..08f336e4246c 100644
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -23,6 +23,7 @@
#include <linux/string.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
+#include <linux/ctype.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinmux.h>
#include "core.h"
@@ -673,6 +674,105 @@ void pinmux_show_setting(struct seq_file *s,
DEFINE_SHOW_ATTRIBUTE(pinmux_functions);
DEFINE_SHOW_ATTRIBUTE(pinmux_pins);
+#define PINMUX_SELECT_MAX 50
+static ssize_t pinmux_select(struct file *file, const char __user *user_buf,
+ size_t len, loff_t *ppos)
+{
+ struct seq_file *sfile = file->private_data;
+ struct pinctrl_dev *pctldev = sfile->private;
+ const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+ const char *const *groups;
+ char *buf, *fname, *gname;
+ unsigned int num_groups;
+ int fsel, gsel, ret;
+
+ if (len > PINMUX_SELECT_MAX)
+ return -ENOMEM;
+
+ buf = kzalloc(PINMUX_SELECT_MAX, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ ret = strncpy_from_user(buf, user_buf, PINMUX_SELECT_MAX);
+ if (ret < 0)
+ goto exit_free_buf;
+ buf[len-1] = '\0';
+
+ /* remove leading and trailing spaces of input buffer */
+ fname = strstrip(buf);
+ if (*fname == '\0') {
+ ret = -EINVAL;
+ goto exit_free_buf;
+ }
+
+ /* find a separator like a space character */
+ for (gname = fname; !isspace(*gname); gname++) {
+ if (*gname == '\0') {
+ ret = -EINVAL;
+ goto exit_free_buf;
+ }
+ }
+ *gname = '\0';
+
+ /* drop extra spaces between function and group name */
+ gname = skip_spaces(gname + 1);
+ if (*gname == '\0') {
+ ret = -EINVAL;
+ goto exit_free_buf;
+ }
+
+ fsel = pinmux_func_name_to_selector(pctldev, fname);
+ if (fsel < 0) {
+ dev_err(pctldev->dev, "invalid function %s in map table\n", fname);
+ ret = fsel;
+ goto exit_free_buf;
+ }
+
+ ret = pmxops->get_function_groups(pctldev, fsel, &groups, &num_groups);
+ if (ret) {
+ dev_err(pctldev->dev, "no groups for function %d (%s)", fsel, fname);
+ goto exit_free_buf;
+ }
+
+ ret = match_string(groups, num_groups, gname);
+ if (ret < 0) {
+ dev_err(pctldev->dev, "invalid group %s", gname);
+ goto exit_free_buf;
+ }
+
+ gsel = pinctrl_get_group_selector(pctldev, gname);
+ if (gsel < 0) {
+ dev_err(pctldev->dev, "failed to get group selector for %s", gname);
+ ret = gsel;
+ goto exit_free_buf;
+ }
+
+ ret = pmxops->set_mux(pctldev, fsel, gsel);
+ if (ret) {
+ dev_err(pctldev->dev, "set_mux() failed: %d", ret);
+ goto exit_free_buf;
+ }
+ ret = len;
+
+exit_free_buf:
+ kfree(buf);
+
+ return ret;
+}
+
+static int pinmux_select_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, NULL, inode->i_private);
+}
+
+static const struct file_operations pinmux_select_ops = {
+ .owner = THIS_MODULE,
+ .open = pinmux_select_open,
+ .write = pinmux_select,
+ .llseek = no_llseek,
+ .release = single_release,
+};
+
void pinmux_init_device_debugfs(struct dentry *devroot,
struct pinctrl_dev *pctldev)
{
@@ -680,6 +780,8 @@ void pinmux_init_device_debugfs(struct dentry *devroot,
devroot, pctldev, &pinmux_functions_fops);
debugfs_create_file("pinmux-pins", 0444,
devroot, pctldev, &pinmux_pins_fops);
+ debugfs_create_file("pinmux-select", 0200,
+ devroot, pctldev, &pinmux_select_ops);
}
#endif /* CONFIG_DEBUG_FS */
--
2.25.1
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