diff options
author | Linus Walleij <linus.walleij@linaro.org> | 2014-10-02 09:55:41 +0400 |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2014-10-02 18:06:59 +0400 |
commit | 27ec8a9cb504e9995c123dc74e0cca0cba81d07f (patch) | |
tree | 7f052c9e5ad3bb2b5babc505cc2cfc994868e36a /drivers/gpio/gpio-stmpe.c | |
parent | 1fe3bd9e347bcea63fa8be212001372720968765 (diff) |
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>
Diffstat (limited to 'drivers/gpio/gpio-stmpe.c')
-rw-r--r-- | drivers/gpio/gpio-stmpe.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-stmpe.c b/drivers/gpio/gpio-stmpe.c index 866baa879473..85c5b1974294 100644 --- a/drivers/gpio/gpio-stmpe.c +++ b/drivers/gpio/gpio-stmpe.c @@ -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) |