Commit 27ec8a9c authored by Linus Walleij's avatar Linus Walleij
Browse files

gpio: stmpe: add verbose debug code 



To troubleshoot the STMPE GPIO driver, some more detailed
debug information giving the exact info on how each pin is
used will be helpful.

Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 1fe3bd9e

drivers/gpio/gpio-stmpe.c

+75 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/interrupt.h>

#include <linux/of.h>

#include <linux/mfd/stmpe.h>

#include <linux/seq_file.h>



/*

 * These registers are modified under the irq bus lock and cached to avoid
@@ -211,6 +212,77 @@ static void stmpe_gpio_irq_unmask(struct irq_data *d) 
	stmpe_gpio->regs[REG_IE][regoffset] |= mask;

}



static void stmpe_dbg_show_one(struct seq_file *s,

			       struct gpio_chip *gc,

			       unsigned offset, unsigned gpio)

{

	struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);

	struct stmpe *stmpe = stmpe_gpio->stmpe;

	const char *label = gpiochip_is_requested(gc, offset);

	int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);

	bool val = !!stmpe_gpio_get(gc, offset);

	u8 dir_reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);

	u8 mask = 1 << (offset % 8);

	int ret;

	u8 dir;



	ret = stmpe_reg_read(stmpe, dir_reg);

	if (ret < 0)

		return;

	dir = !!(ret & mask);



	if (dir) {

		seq_printf(s, " gpio-%-3d (%-20.20s) out %s",

			   gpio, label ?: "(none)",

			   val ? "hi" : "lo");

	} else {

		u8 edge_det_reg = stmpe->regs[STMPE_IDX_GPEDR_MSB] + num_banks - 1 - (offset / 8);

		u8 rise_reg = stmpe->regs[STMPE_IDX_GPRER_LSB] - (offset / 8);

		u8 fall_reg = stmpe->regs[STMPE_IDX_GPFER_LSB] - (offset / 8);

		u8 irqen_reg = stmpe->regs[STMPE_IDX_IEGPIOR_LSB] - (offset / 8);

		bool edge_det;

		bool rise;

		bool fall;

		bool irqen;



		ret = stmpe_reg_read(stmpe, edge_det_reg);

		if (ret < 0)

			return;

		edge_det = !!(ret & mask);

		ret = stmpe_reg_read(stmpe, rise_reg);

		if (ret < 0)

			return;

		rise = !!(ret & mask);

		ret = stmpe_reg_read(stmpe, fall_reg);

		if (ret < 0)

			return;

		fall = !!(ret & mask);

		ret = stmpe_reg_read(stmpe, irqen_reg);

		if (ret < 0)

			return;

		irqen = !!(ret & mask);



		seq_printf(s, " gpio-%-3d (%-20.20s) in  %s %s %s%s%s",

			   gpio, label ?: "(none)",

			   val ? "hi" : "lo",

			   edge_det ? "edge-asserted" : "edge-inactive",

			   irqen ? "IRQ-enabled" : "",

			   rise ? " rising-edge-detection" : "",

			   fall ? " falling-edge-detection" : "");

	}

}



static void stmpe_dbg_show(struct seq_file *s, struct gpio_chip *gc)

{

	unsigned i;

	unsigned gpio = gc->base;



	for (i = 0; i < gc->ngpio; i++, gpio++) {

		stmpe_dbg_show_one(s, gc, i, gpio);

		seq_printf(s, "\n");

	}

}



static struct irq_chip stmpe_gpio_irq_chip = {

	.name			= "stmpe-gpio",

	.irq_bus_lock		= stmpe_gpio_irq_lock,
@@ -293,6 +365,9 @@ static int stmpe_gpio_probe(struct platform_device *pdev) 
#endif

	stmpe_gpio->chip.base = -1;



	if (IS_ENABLED(CONFIG_DEBUG_FS))

                stmpe_gpio->chip.dbg_show = stmpe_dbg_show;



	if (pdata)

		stmpe_gpio->norequest_mask = pdata->norequest_mask;

	else if (np)