From: Drew Fustini <drew@beagleboard.org>
To: Linus Walleij <linus.walleij@linaro.org>,
linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
Tony Lindgren <tony@atomide.com>,
Andy Shevchenko <andy.shevchenko@gmail.com>,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Pantelis Antoniou <pantelis.antoniou@konsulko.com>,
Jason Kridner <jkridner@beagleboard.org>,
Robert Nelson <robertcnelson@beagleboard.org>,
Joe Perches <joe@perches.com>,
Dan Carpenter <dan.carpenter@oracle.com>
Cc: Drew Fustini <drew@beagleboard.org>
Subject: [PATCH v5 2/2] pinctrl: pinmux: Add pinmux-select debugfs file
Date: Fri, 12 Feb 2021 14:30:15 -0800 [thread overview]
Message-ID: <20210212223015.727608-3-drew@beagleboard.org> (raw)
In-Reply-To: <20210212223015.727608-1-drew@beagleboard.org>
Add "pinmux-select" to debugfs which will activate a function and group
when "<function-name group-name>" are written to the file. 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@beagleboard.org>
---
drivers/pinctrl/pinmux.c | 99 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 99 insertions(+)
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
index c651b2db0925..c16a6167ac3a 100644
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -673,6 +673,103 @@ void pinmux_show_setting(struct seq_file *s,
DEFINE_SHOW_ATTRIBUTE(pinmux_functions);
DEFINE_SHOW_ATTRIBUTE(pinmux_pins);
+#define PINMUX_SELECT_MAX 128
+static ssize_t pinmux_select(struct file *file, const char __user *user_buf,
+ size_t len, loff_t *ppos)
+{
+ const char *usage =
+ "usage: echo '<function-name> <group-name>' > pinmux-select";
+ 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) {
+ dev_err(pctldev->dev, "write too big for buffer");
+ return -EINVAL;
+ }
+
+ buf = kzalloc(PINMUX_SELECT_MAX, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ ret = strncpy_from_user(buf, user_buf, PINMUX_SELECT_MAX);
+ if (ret < 0) {
+ dev_err(pctldev->dev, "failed to copy buffer from userspace");
+ goto free_buf;
+ }
+ buf[len-1] = '\0';
+
+ fname = strstrip(buf);
+ if (*fname == '\0') {
+ dev_err(pctldev->dev, usage);
+ ret = -EINVAL;
+ goto free_buf;
+ }
+
+ gname = strchr(fname, ' ');
+ if (!gname) {
+ dev_err(pctldev->dev, usage);
+ ret = -EINVAL;
+ goto free_buf;
+ }
+ *gname++ = '\0';
+
+ 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 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 free_buf;
+ }
+
+ ret = match_string(groups, num_groups, gname);
+ if (ret < 0) {
+ dev_err(pctldev->dev, "invalid group %s", gname);
+ goto 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 free_buf;
+ }
+
+ ret = pmxops->set_mux(pctldev, fsel, gsel);
+ if (ret) {
+ dev_err(pctldev->dev, "set_mux() failed: %d", ret);
+ goto free_buf;
+ }
+ ret = len;
+
+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 +777,8 @@ 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
next prev parent reply other threads:[~2021-02-12 22:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-12 22:30 [PATCH v5 0/2] pinctrl: pinmux: Add pinmux-select debugfs file Drew Fustini
2021-02-12 22:30 ` [PATCH v5 1/2] pinctrl: use to octal permissions for debugfs files Drew Fustini
2021-02-13 12:56 ` Andy Shevchenko
2021-02-16 8:41 ` Geert Uytterhoeven
2021-03-02 8:36 ` Linus Walleij
2021-03-02 10:23 ` Andy Shevchenko
2021-03-02 16:22 ` Linus Walleij
2021-03-02 17:10 ` Drew Fustini
2021-02-12 22:30 ` Drew Fustini [this message]
2021-02-15 19:04 ` [PATCH v5 2/2] pinctrl: pinmux: Add pinmux-select debugfs file Andy Shevchenko
2021-02-15 21:09 ` Drew Fustini
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