Re: [PATCH v6 2/3] pinctrl: pinmux: Add pinmux-select debugfs file
From: Andy Shevchenko <hidden>
Date: 2021-02-17 10:11:39
Also in:
linux-gpio, lkml
On Wed, Feb 17, 2021 at 12:45 AM Drew Fustini [off-list ref] wrote:
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
Thanks, looks almost good to me (few nit-picks below) Reviewed-by: Andy Shevchenko <redacted>
quoted hunk ↗ jump to hunk
Signed-off-by: Drew Fustini <redacted> --- 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>
Perhaps squeeze it to look slightly more ordered?
quoted hunk ↗ jump to hunk
#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
Why suddenly this number? Maybe 64 for the sake of good power of 2?
+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 */"find a separator which is a spacelike 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 */names
+ 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;
+ }
Here and below you could do other way around, i.e.
ret = ...
if (ret < 0) {
...
}
fsel = ret;
quoted hunk ↗ jump to hunk
+ 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
-- With Best Regards, Andy Shevchenko