diff options
author | Drew Fustini <drew@beagleboard.org> | 2021-03-02 08:30:57 +0300 |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2021-03-10 16:41:58 +0300 |
commit | 6199f6becc869d30ca9394ca0f7a484bf9d598eb (patch) | |
tree | 044f52440337b5df0907b0380d01fd520d1a8abe /drivers/pinctrl | |
parent | 47473813bdcb8c5ffa87f6d2ccb378b9b0882c83 (diff) | |
download | linux-6199f6becc869d30ca9394ca0f7a484bf9d598eb.tar.xz |
pinctrl: pinmux: Add pinmux-select debugfs file
Add "pinmux-select" to debugfs which will activate a pin function for a
given pin group:
echo "<group-name function-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 on group pinmux-i2c1-pins:
echo "pinmux-i2c1-pins pinmux-i2c1" > pinmux-select
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Drew Fustini <drew@beagleboard.org>
Link: https://lore.kernel.org/r/20210302053059.1049035-3-drew@beagleboard.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/pinctrl')
-rw-r--r-- | drivers/pinctrl/pinmux.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c index 9c0174520e78..6cdbd9ccf2f0 100644 --- a/drivers/pinctrl/pinmux.c +++ b/drivers/pinctrl/pinmux.c @@ -12,6 +12,7 @@ */ #define pr_fmt(fmt) "pinmux core: " fmt +#include <linux/ctype.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.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 128 +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, *gname, *fname; + 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 */ + gname = strstrip(buf); + if (*gname == '\0') { + ret = -EINVAL; + goto exit_free_buf; + } + + /* find a separator which is a spacelike character */ + for (fname = gname; !isspace(*fname); fname++) { + if (*fname == '\0') { + ret = -EINVAL; + goto exit_free_buf; + } + } + *fname = '\0'; + + /* drop extra spaces between function and group names */ + fname = skip_spaces(fname + 1); + if (*fname == '\0') { + ret = -EINVAL; + goto exit_free_buf; + } + + ret = pinmux_func_name_to_selector(pctldev, fname); + if (ret < 0) { + dev_err(pctldev->dev, "invalid function %s in map table\n", fname); + goto exit_free_buf; + } + fsel = ret; + + 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; + } + + ret = pinctrl_get_group_selector(pctldev, gname); + if (ret < 0) { + dev_err(pctldev->dev, "failed to get group selector for %s", gname); + goto exit_free_buf; + } + gsel = ret; + + 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 */ |