pinctrl: pinctrl-single: fix pcs_pin_dbg_show() when bits_per_mux is not zero

A System Error (SError, followed by kernel panic) 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 <hhhawa@amazon.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Drew Fustini <drew@beagleboard.org>
Link: https://lore.kernel.org/r/20210319152133.28705-4-hhhawa@amazon.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
index f339451..39aac32 100644 (file)
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -270,20 +270,44 @@ static void __maybe_unused pcs_writel(unsigned val, void __iomem *reg)
        writel(val, reg);
 }
 
+static unsigned int pcs_pin_reg_offset_get(struct pcs_device *pcs,
+                                          unsigned int pin)
+{
+       unsigned int mux_bytes = pcs->width / BITS_PER_BYTE;
+
+       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;
+       }
+
+       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;
+}
+
 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 +408,6 @@ 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 +415,27 @@ 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 +745,8 @@ 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);