| Message ID | 20210217221457.1827266-3-drew@beagleboard.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | pinctrl: pinmux: Add pinmux-select debugfs file | expand |
Hi Drew, On Wed, Feb 17, 2021 at 11:15 PM Drew Fustini <drew@beagleboard.org> 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 > > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > Reviewed-by: Tony Lindgren <tony@atomide.com> > Signed-off-by: Drew Fustini <drew@beagleboard.org> Thanks for your patch! On R-Car M2-W, which does not use pinctrl-single, I have: # cat pinmux-functions ... function 14: i2c2, groups = [ i2c2 i2c2_b i2c2_c i2c2_d ] ... function 51: ssi, groups = [ ssi0_data ssi0_data_b ssi0129_ctrl ssi0129_ctrl_b ssi1_data ssi1_data_b ssi1_ctrl ssi1_ctrl_b ssi2_data ssi2_ctrl ssi3_data ssi34_ctrl ssi4_data ssi4_ctrl ssi5_data ssi5_ctrl ssi6_data ssi6_ctrl ssi7_data ssi7_data_b ssi78_ctrl ssi78_ctrl_b ssi8_data ssi8_data_b ssi9_data ssi9_data_b ssi9_ctrl ssi9_ctrl_b ] ... On the Koelsch board: # cd /sys/kernel/debug/pinctrl/e6060000.pinctrl-sh-pfc/ # echo ssi ssi2_ctrl > pinmux-select # Configure i2c2 pins for ssi # i2cdetect -y -a 2 # Fails # echo i2c2 i2c2 > pinmux-select # Restore i2c2 # i2cdetect -y -a 2 # Works again The order of the 2 parameters looks a bit odd to me, as the operation configures the pins from "group" to be used for "function". See also arch/arm/boot/dts/r8a7791-koelsch.dts For the i2c2 example it's not that obvious, but for ssi it is. Might feel different for pinctrl-single, and perhaps I just need to get used to it ;-) Anyway: Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Fri, Feb 19, 2021 at 10:06:51AM +0100, Geert Uytterhoeven wrote: > Hi Drew, > > On Wed, Feb 17, 2021 at 11:15 PM Drew Fustini <drew@beagleboard.org> 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 > > > > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > > Reviewed-by: Tony Lindgren <tony@atomide.com> > > Signed-off-by: Drew Fustini <drew@beagleboard.org> > > Thanks for your patch! > > On R-Car M2-W, which does not use pinctrl-single, I have: > > # cat pinmux-functions > ... > function 14: i2c2, groups = [ i2c2 i2c2_b i2c2_c i2c2_d ] > ... > function 51: ssi, groups = [ ssi0_data ssi0_data_b ssi0129_ctrl > ssi0129_ctrl_b ssi1_data ssi1_data_b ssi1_ctrl ssi1_ctrl_b ssi2_data > ssi2_ctrl ssi3_data ssi34_ctrl ssi4_data ssi4_ctrl ssi5_data ssi5_ctrl > ssi6_data ssi6_ctrl ssi7_data ssi7_data_b ssi78_ctrl ssi78_ctrl_b > ssi8_data ssi8_data_b ssi9_data ssi9_data_b ssi9_ctrl ssi9_ctrl_b ] > ... > > On the Koelsch board: > > # cd /sys/kernel/debug/pinctrl/e6060000.pinctrl-sh-pfc/ > # echo ssi ssi2_ctrl > pinmux-select # Configure i2c2 pins for ssi > # i2cdetect -y -a 2 # Fails > # echo i2c2 i2c2 > pinmux-select # Restore i2c2 > # i2cdetect -y -a 2 # Works again > > The order of the 2 parameters looks a bit odd to me, as the operation > configures the pins from "group" to be used for "function". > See also arch/arm/boot/dts/r8a7791-koelsch.dts > For the i2c2 example it's not that obvious, but for ssi it is. > Might feel different for pinctrl-single, and perhaps I just need to get > used to it ;-) Thank you for comments and testing. Regarding the order of "<function-name> <group-name>", I can change it to "<group-name function-name>" if that seems more natural. pinctrl-single does not actually use the group selector in pcs_set_mux() so it essentially does not matter for pinctrl-single. -Drew > > Anyway: > Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> > Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> > > Gr{oetje,eeting}s, > > Geert > > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c index c651b2db0925..39770af56562 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 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 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 names */ + gname = skip_spaces(gname + 1); + if (*gname == '\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 */