ARM: Orion: add dbg_show function to gpio-orion driver

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: Jason Cooper <jason@lakedaemon.net>

1 files changed, 59 insertions, 0 deletions

diff --git a/arch/arm/plat-orion/gpio.c b/arch/arm/plat-orion/gpio.c
index c29ee7ea200b..e39c2ba6e2fb 100644
--- a/arch/arm/plat-orion/gpio.c
+++ b/arch/arm/plat-orion/gpio.c
@@ -439,6 +439,64 @@ static void gpio_irq_handler(unsigned irq, struct irq_desc *desc)
         }
 }
 
+#ifdef CONFIG_DEBUG_FS
+#include <linux/seq_file.h>
+
+static void orion_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
+{
+        struct orion_gpio_chip *ochip =
+                container_of(chip, struct orion_gpio_chip, chip);
+        u32 out, io_conf, blink, in_pol, data_in, cause, edg_msk, lvl_msk;
+        int i;
+
+        out     = readl_relaxed(GPIO_OUT(ochip));
+        io_conf = readl_relaxed(GPIO_IO_CONF(ochip));
+        blink   = readl_relaxed(GPIO_BLINK_EN(ochip));
+        in_pol  = readl_relaxed(GPIO_IN_POL(ochip));
+        data_in = readl_relaxed(GPIO_DATA_IN(ochip));
+        cause   = readl_relaxed(GPIO_EDGE_CAUSE(ochip));
+        edg_msk = readl_relaxed(GPIO_EDGE_MASK(ochip));
+        lvl_msk = readl_relaxed(GPIO_LEVEL_MASK(ochip));
+
+        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 orion_gpio_dbg_show NULL
+#endif
+
 void __init orion_gpio_init(struct device_node *np,
                             int gpio_base, int ngpio,
                             void __iomem *base, int mask_offset,
@@ -471,6 +529,7 @@ void __init orion_gpio_init(struct device_node *np,
 #ifdef CONFIG_OF
         ochip->chip.of_node = np;
 #endif
+        ochip->chip.dbg_show = orion_gpio_dbg_show;
 
         spin_lock_init(&ochip->lock);
         ochip->base = (void __iomem *)base;