Fix pinctrl-single pcs_pin_dbg_show()

An SError was detected when trying to print the supported pins in a

pinctrl device which supports multiple pins per register. This change fixes the pcs_pin_dbg_show() in pinctrl-single driver when bits_per_mux is not zero. In addition move offset calculation and pin offset in register to common function.

Fixes 4e7e8017a80e ("pinctrl: pinctrl-single: enhance to configure multiple pins of different modules")

Signed-off-by Hanna Hawa <[email protected]>

---
 drivers/pinctrl/pinctrl-single.c | 57 +++++++++++++++++++++-----------
 1 file changed, 37 insertions(+), 20 deletions(-)

drivers/pinctrl/pinctrl-single.c +0 -0

index f3394517cb2e..4595acf6545e 100644

drivers/pinctrl/pinctrl-single.c +16 -21

+}
+
 static void pcs_pin_dbg_show(struct pinctrl_dev *pctldev,
                                        struct seq_file *s,
                                        unsigned pin)
 {
        struct pcs_device *pcs;
-       unsigned val, mux_bytes;
+       unsigned int val;
        unsigned long offset;
        size_t pa;
 
        pcs = pinctrl_dev_get_drvdata(pctldev);
 
-       mux_bytes = pcs->width / BITS_PER_BYTE;
-       offset = pin * mux_bytes;
+       offset = pcs_pin_reg_offset_get(pcs, pin);
        val = pcs->read(pcs->base + offset);
+
+       if (pcs->bits_per_mux)
+               val &= pcs->fmask << pcs_pin_shift_reg_get(pcs, pin);
+
        pa = pcs->res->start + offset;
 
        seq_printf(s, "%zx %08x %s ", pa, val, DRIVER_NAME);

@@ -384,7 +410,6 @@ static int pcs_request_gpio(struct pinctrl_dev *pctldev,
        struct pcs_device *pcs = pinctrl_dev_get_drvdata(pctldev);
        struct pcs_gpiofunc_range *frange = NULL;
        struct list_head *pos, *tmp;
-       int mux_bytes = 0;
        unsigned data;
 
        /* If function mask is null, return directly. */

@@ -392,29 +417,27 @@ static int pcs_request_gpio(struct pinctrl_dev *pctldev,
                return -ENOTSUPP;
 
        list_for_each_safe(pos, tmp, &pcs->gpiofuncs) {
+               u32 offset;
+
                frange = list_entry(pos, struct pcs_gpiofunc_range, node);
                if (pin >= frange->offset + frange->npins
                        || pin < frange->offset)
                        continue;
-               mux_bytes = pcs->width / BITS_PER_BYTE;
 
-               if (pcs->bits_per_mux) {
-                       int byte_num, offset, pin_shift;
+               offset = pcs_pin_reg_offset_get(pcs, pin);
 
-                       byte_num = (pcs->bits_per_pin * pin) / BITS_PER_BYTE;
-                       offset = (byte_num / mux_bytes) * mux_bytes;
-                       pin_shift = pin % (pcs->width / pcs->bits_per_pin) *
-                                   pcs->bits_per_pin;
+               if (pcs->bits_per_mux) {
+                       int pin_shift = pcs_pin_shift_reg_get(pcs, pin);
 
                        data = pcs->read(pcs->base + offset);
                        data &= ~(pcs->fmask << pin_shift);
                        data |= frange->gpiofunc << pin_shift;
                        pcs->write(data, pcs->base + offset);
                } else {
-                       data = pcs->read(pcs->base + pin * mux_bytes);
+                       data = pcs->read(pcs->base + offset);
                        data &= ~pcs->fmask;
                        data |= frange->gpiofunc;
-                       pcs->write(data, pcs->base + pin * mux_bytes);
+                       pcs->write(data, pcs->base + offset);
                }
                break;
        }

@@ -724,14 +747,8 @@ static int pcs_allocate_pin_table(struct pcs_device *pcs)
        for (i = 0; i < pcs->desc.npins; i++) {
                unsigned offset;
                int res;
-               int byte_num;
 
-               if (pcs->bits_per_mux) {
-                       byte_num = (pcs->bits_per_pin * i) / BITS_PER_BYTE;
-                       offset = (byte_num / mux_bytes) * mux_bytes;
-               } else {
-                       offset = i * mux_bytes;
-               }
+               offset = pcs_pin_reg_offset_get(pcs, i);
                res = pcs_add_pin(pcs, offset);
                if (res < 0) {
                        dev_err(pcs->dev, "error adding pins: %i\n", res);
--

2.17.1

Quoted 1 line · Hanna Hawa

An SError was detected when trying to print the supported pins in a

What is SError? Yes, I have read a discussion, but here is the hint:
if a person sees this as a first text due to, for example, bisecting an issue, what she/he can get from this cryptic name?

Quoted 5 lines

pinctrl device which supports multiple pins per register. This change fixes the pcs_pin_dbg_show() in pinctrl-single driver when bits_per_mux is not zero. In addition move offset calculation and pin offset in register to common function.

Reviewed-by Andy Shevchenko<[email protected]>

Quoted 15 lines

Fixes 4e7e8017a80e ("pinctrl: pinctrl-single: enhance to configure multiple pins of different modules")

Signed-off-by Hanna Hawa<[email protected]>

---
  drivers/pinctrl/pinctrl-single.c | 57 +++++++++++++++++++++-----------
  1 file changed, 37 insertions(+), 20 deletions(-)

drivers/pinctrl/pinctrl-single.c +0 -0

index f3394517cb2e..4595acf6545e 100644
@@ -270,20 +270,46 @@ static void __maybe_unused pcs_writel(unsigned val, void __iomem *reg)
         writel(val, reg);
  }
 

drivers/pinctrl/pinctrl-single.c static void __maybe_unused pcs_writel(unsigned val, void __iomem *reg) · line 278

Quoted 6 lines

drivers/pinctrl/pinctrl-single.c +6 -0

+static unsigned int pcs_pin_reg_offset_get(struct pcs_device *pcs,
+                                          unsigned int pin)
+{
+       unsigned int mux_bytes;
+
+       mux_bytes = pcs->width / BITS_PER_BYTE;

Can be folded to one line.

drivers/pinctrl/pinctrl-single.c static void __maybe_unused pcs_writel(unsigned val, void __iomem *reg) · line 284

Quoted 6 lines

drivers/pinctrl/pinctrl-single.c +5 -0

+       if (pcs->bits_per_mux) {
+               unsigned int pin_offset_bytes;
+
+               pin_offset_bytes = (pcs->bits_per_pin * pin) / BITS_PER_BYTE;
+               return (pin_offset_bytes / mux_bytes) * mux_bytes;

Side note for the further improvements (in a separate change, because I see that you just copied an original code, and after all this is just a fix patch): this can be replaced by round down APIs (one which works for arbitrary divisors).

drivers/pinctrl/pinctrl-single.c static void __maybe_unused pcs_writel(unsigned val, void __iomem *reg) · line 293

Quoted 10 lines

drivers/pinctrl/pinctrl-single.c +9 -0

+       }
+
+       return pin * mux_bytes;
+}
+
+static unsigned int pcs_pin_shift_reg_get(struct pcs_device *pcs,
+                                         unsigned int pin)
+{
+       return (pin % (pcs->width / pcs->bits_per_pin)) * pcs->bits_per_pin;

Also a side note: I'm wondering if this can be optimized to have less divisions.

drivers/pinctrl/pinctrl-single.c static void __maybe_unused pcs_writel(unsigned val, void __iomem *reg) · line 299

Quoted 6 lines

drivers/pinctrl/pinctrl-single.c +2 -0

+}
+
  static void pcs_pin_dbg_show(struct pinctrl_dev *pctldev,
                                         struct seq_file *s,
                                         unsigned pin)
  {

Quoted 5 lines · Andy Shevchenko

Quoted 1 line · Hanna Hawa

An SError was detected when trying to print the supported pins in a

What is SError? Yes, I have read a discussion, but here is the hint:
if a person sees this as a first text due to, for example, bisecting an issue, what she/he can get from this cryptic name?

What you suggest?
s/An SError/A kernel-panic/?

Or remove the sentence and keep the below:
"
This change fixes the pcs_pin_dbg_show() in pinctrl-single driver when bits_per_mux is not zero. In addition move offset calculation and pin offset in register to common function.
"