Commit 430c1ce3 authored by Jan Kundrát's avatar Jan Kundrát Committed by Linus Walleij
Browse files

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: default avatarJan Kundrát <jan.kundrat@cesnet.cz>
Cc: Phil Reid <preid@electromag.com.au>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 77bc0e69

drivers/pinctrl/pinctrl-mcp23s08.c

+0 −110
Original line number Diff line number Diff line
@@ -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;

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