pinctrl: mcp23s08: debugfs: remove custom printer

The comment for this dbg_show says that it is supposed to return more
than what the generic code is showing, including de-glitching. That's
wrong because:

- this chip does not support deglitching,
- the code does not print anything extra compared to the generic
handler,
- its behavior is different because it skips unrequested GPIOs; the
generic code prints their names if they're assigned

There is an important difference, though. Previously, dbg_show would
re-check some registers to see if they still match what the regmap
thinks should be in there. This was semi-useful when develpoing the HW
board because it immediately pointed to SPI wiring problem if a CS
connection was missing (0xffs are easy to see). However, I do not think
that this makes much sense -- and one could always do this in some other
way if needed.
Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Cc: Phil Reid <preid@electromag.com.au>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-mcp23s08.c

@@ -656,115 +656,6 @@ static int mcp23s08_irqchip_setup(struct mcp23s08 *mcp)
 
 /*----------------------------------------------------------------------*/
 
-#ifdef CONFIG_DEBUG_FS
-
-#include <linux/seq_file.h>
-
-/*
- * This compares the chip's registers with the register
- * cache and corrects any incorrectly set register. This
- * can be used to fix state for MCP23xxx, that temporary
- * lost its power supply.
- */
-#define MCP23S08_CONFIG_REGS 7
-static int __check_mcp23s08_reg_cache(struct mcp23s08 *mcp)
-{
-	int cached[MCP23S08_CONFIG_REGS];
-	int err = 0, i;
-
-	/* read cached config registers */
-	for (i = 0; i < MCP23S08_CONFIG_REGS; i++) {
-		err = mcp_read(mcp, i, &cached[i]);
-		if (err)
-			goto out;
-	}
-
-	regcache_cache_bypass(mcp->regmap, true);
-
-	for (i = 0; i < MCP23S08_CONFIG_REGS; i++) {
-		int uncached;
-		err = mcp_read(mcp, i, &uncached);
-		if (err)
-			goto out;
-
-		if (uncached != cached[i]) {
-			dev_err(mcp->dev, "restoring reg 0x%02x from 0x%04x to 0x%04x (power-loss?)\n",
-				i, uncached, cached[i]);
-			mcp_write(mcp, i, cached[i]);
-		}
-	}
-
-out:
-	if (err)
-		dev_err(mcp->dev, "read error: reg=%02x, err=%d", i, err);
-	regcache_cache_bypass(mcp->regmap, false);
-	return err;
-}
-
-/*
- * This shows more info than the generic gpio dump code:
- * pullups, deglitching, open drain drive.
- */
-static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
-{
-	struct mcp23s08	*mcp;
-	char		bank;
-	int		t;
-	unsigned	mask;
-	int iodir, gpio, gppu;
-
-	mcp = gpiochip_get_data(chip);
-
-	/* NOTE: we only handle one bank for now ... */
-	bank = '0' + ((mcp->addr >> 1) & 0x7);
-
-	mutex_lock(&mcp->lock);
-
-	t = __check_mcp23s08_reg_cache(mcp);
-	if (t) {
-		seq_printf(s, " I/O Error\n");
-		goto done;
-	}
-	t = mcp_read(mcp, MCP_IODIR, &iodir);
-	if (t) {
-		seq_printf(s, " I/O Error\n");
-		goto done;
-	}
-	t = mcp_read(mcp, MCP_GPIO, &gpio);
-	if (t) {
-		seq_printf(s, " I/O Error\n");
-		goto done;
-	}
-	t = mcp_read(mcp, MCP_GPPU, &gppu);
-	if (t) {
-		seq_printf(s, " I/O Error\n");
-		goto done;
-	}
-
-	for (t = 0, mask = BIT(0); t < chip->ngpio; t++, mask <<= 1) {
-		const char *label;
-
-		label = gpiochip_is_requested(chip, t);
-		if (!label)
-			continue;
-
-		seq_printf(s, " gpio-%-3d P%c.%d (%-12s) %s %s %s\n",
-			   chip->base + t, bank, t, label,
-			   (iodir & mask) ? "in " : "out",
-			   (gpio & mask) ? "hi" : "lo",
-			   (gppu & mask) ? "up" : "  ");
-		/* NOTE:  ignoring the irq-related registers */
-	}
-done:
-	mutex_unlock(&mcp->lock);
-}
-
-#else
-#define mcp23s08_dbg_show	NULL
-#endif
-
-/*----------------------------------------------------------------------*/
-
 static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
 			      void *data, unsigned addr, unsigned type,
 			      unsigned int base, int cs)
@@ -785,7 +676,6 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
 	mcp->chip.get = mcp23s08_get;
 	mcp->chip.direction_output = mcp23s08_direction_output;
 	mcp->chip.set = mcp23s08_set;
-	mcp->chip.dbg_show = mcp23s08_dbg_show;
 #ifdef CONFIG_OF_GPIO
 	mcp->chip.of_gpio_n_cells = 2;
 	mcp->chip.of_node = dev->of_node;