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pinctrl: mcp23s08: debugfs: remove custom printer

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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>
This commit is contained in:
Jan Kundrát 2019-03-07 14:38:04 +01:00 committed by Linus Walleij
parent 77bc0e69c3
commit 430c1ce304
1 changed files with 0 additions and 110 deletions
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110
drivers/pinctrl/pinctrl-mcp23s08.c
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@ -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;