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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: Linus Walleij <linus.walleij@linaro.org>
hifive-unleashed-5.1
Linus Walleij 2014-10-02 07:55:41 +02:00
parent 1fe3bd9e34
commit 27ec8a9cb5
1 changed files with 75 additions and 0 deletions

View File

@ -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)