gpio: mvebu: add dbg_show function

This patch adds a dedicated dbg_show function to the gpio-mvebu driver.
In addition to the generic gpiolib informations, this function displays
informations related with the specific Marvell registers (blink enable,
data in polarity, interrupt masks and cause).

Signed-off-by: Simon Guinot <simon.guinot@sequanux.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index 474823e403fa6fbb07eae86710383047a9cc7998..f7db3b336343dc12565957b91c33374150fc6f0c 100644 (file)
--- a/drivers/gpio/gpio-mvebu.c
+++ b/drivers/gpio/gpio-mvebu.c
@@ -469,6 +469,64 @@ static void mvebu_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
        }
 }
 
+#ifdef CONFIG_DEBUG_FS
+#include <linux/seq_file.h>
+
+static void mvebu_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
+{
+       struct mvebu_gpio_chip *mvchip =
+               container_of(chip, struct mvebu_gpio_chip, chip);
+       u32 out, io_conf, blink, in_pol, data_in, cause, edg_msk, lvl_msk;
+       int i;
+
+       out     = readl_relaxed(mvebu_gpioreg_out(mvchip));
+       io_conf = readl_relaxed(mvebu_gpioreg_io_conf(mvchip));
+       blink   = readl_relaxed(mvebu_gpioreg_blink(mvchip));
+       in_pol  = readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
+       data_in = readl_relaxed(mvebu_gpioreg_data_in(mvchip));
+       cause   = readl_relaxed(mvebu_gpioreg_edge_cause(mvchip));
+       edg_msk = readl_relaxed(mvebu_gpioreg_edge_mask(mvchip));
+       lvl_msk = readl_relaxed(mvebu_gpioreg_level_mask(mvchip));
+
+       for (i = 0; i < chip->ngpio; i++) {
+               const char *label;
+               u32 msk;
+               bool is_out;
+
+               label = gpiochip_is_requested(chip, i);
+               if (!label)
+                       continue;
+
+               msk = 1 << i;
+               is_out = !(io_conf & msk);
+
+               seq_printf(s, " gpio-%-3d (%-20.20s)", chip->base + i, label);
+
+               if (is_out) {
+                       seq_printf(s, " out %s %s\n",
+                                  out & msk ? "hi" : "lo",
+                                  blink & msk ? "(blink )" : "");
+                       continue;
+               }
+
+               seq_printf(s, " in  %s (act %s) - IRQ",
+                          (data_in ^ in_pol) & msk  ? "hi" : "lo",
+                          in_pol & msk ? "lo" : "hi");
+               if (!((edg_msk | lvl_msk) & msk)) {
+                       seq_printf(s, " disabled\n");
+                       continue;
+               }
+               if (edg_msk & msk)
+                       seq_printf(s, " edge ");
+               if (lvl_msk & msk)
+                       seq_printf(s, " level");
+               seq_printf(s, " (%s)\n", cause & msk ? "pending" : "clear  ");
+       }
+}
+#else
+#define mvebu_gpio_dbg_show NULL
+#endif
+
 static struct of_device_id mvebu_gpio_of_match[] = {
        {
                .compatible = "marvell,orion-gpio",
@@ -543,6 +601,7 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
        mvchip->chip.ngpio = ngpios;
        mvchip->chip.can_sleep = 0;
        mvchip->chip.of_node = np;
+       mvchip->chip.dbg_show = mvebu_gpio_dbg_show;
 
        spin_lock_init(&mvchip->lock);
        mvchip->membase = devm_ioremap_resource(&pdev->dev, res);