[RFC 06/15] gpio: add restrack support

From: Andrzej Hajda
Date: Wed Dec 10 2014 - 10:52:35 EST


GPIO supports different methods of lookup.
The patch adds restrack support only to DT based GPIOs.

Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
---
drivers/gpio/gpiolib.c | 81 +++++++++++++++++++++++++++++++++++++++++++
include/linux/gpio/consumer.h | 4 +++
include/linux/restrack.h | 1 +
3 files changed, 86 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 78fcec9..5d85e20 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -15,6 +15,7 @@
#include <linux/acpi.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
+#include <linux/restrack.h>

#include "gpiolib.h"

@@ -278,6 +279,8 @@ int gpiochip_add(struct gpio_chip *chip)
if (status)
goto fail;

+ restrack_up(RESTRACK_TYPE_GPIO, chip->of_node, chip);
+
status = gpiochip_export(chip);
if (status)
goto fail;
@@ -313,6 +316,7 @@ void gpiochip_remove(struct gpio_chip *chip)
unsigned long flags;
unsigned id;

+ restrack_down(RESTRACK_TYPE_GPIO, chip->of_node, chip);
acpi_gpiochip_remove(chip);

spin_lock_irqsave(&gpio_lock, flags);
@@ -1770,6 +1774,83 @@ void gpiod_put(struct gpio_desc *desc)
}
EXPORT_SYMBOL_GPL(gpiod_put);

+struct gpiod_restrack_desc {
+ struct gpio_desc **ptr;
+ const char *name;
+ enum gpiod_flags flags;
+ struct of_phandle_args spec;
+ struct restrack_desc desc;
+};
+
+static int gpiod_restrack_init(struct device *dev, struct restrack_desc *desc)
+{
+ struct gpiod_restrack_desc *rd = restrack_desc_to_rd(rd, desc);
+ int ret;
+
+ ret = of_get_gpiod_spec(dev, rd->name, 0, &rd->spec);
+ if (!ret)
+ desc->if_id = rd->spec.np;
+ return ret;
+}
+
+static void gpiod_restrack_destroy(struct device *dev,
+ struct restrack_desc *desc)
+{
+ struct gpiod_restrack_desc *rd = restrack_desc_to_rd(rd, desc);
+
+ of_node_put(desc->if_id);
+ kfree(rd);
+}
+
+static int gpiod_restrack_ifup(struct device *dev, struct restrack_desc *desc,
+ void *data)
+{
+ struct gpiod_restrack_desc *rd = restrack_desc_to_rd(rd, desc);
+
+ *rd->ptr = gpiod_get(dev, rd->name, rd->flags);
+ return PTR_ERR_OR_ZERO(*rd->ptr);
+}
+
+static void gpiod_restrack_ifdown(struct device *dev,
+ struct restrack_desc *desc, void *data)
+{
+ struct gpiod_restrack_desc *rd = restrack_desc_to_rd(rd, desc);
+
+ gpiod_put(*rd->ptr);
+ *rd->ptr = ERR_PTR(-EPROBE_DEFER);
+}
+
+static const struct restrack_ops gpiod_restrack_ops = {
+ .if_type = RESTRACK_TYPE_GPIO,
+ .init = gpiod_restrack_init,
+ .destroy = gpiod_restrack_destroy,
+ .if_up = gpiod_restrack_ifup,
+ .if_down = gpiod_restrack_ifdown,
+};
+
+/**
+ * gpiod_restrack_desc - gpio resource descriptor allocator
+ * @gpiod: pointer to variable which will be set to gpiod handle
+ * @name: name of gpio
+ * @flags: gpiod flags
+ *
+ * The function creates resource description for gpio, which shall be used
+ * by *restrack_register functions.
+ */
+struct restrack_desc *gpiod_restrack_desc(struct gpio_desc **gpiod,
+ const char *con_id, enum gpiod_flags flags)
+{
+ struct gpiod_restrack_desc *rd;
+
+ RESTRACK_DESC_ALLOC(rd, gpiod_restrack_ops, gpiod, con_id);
+ if (!rd)
+ return ERR_PTR(-ENOMEM);
+
+ rd->flags = flags;
+ return &rd->desc;
+}
+EXPORT_SYMBOL_GPL(gpiod_restrack_desc);
+
#ifdef CONFIG_DEBUG_FS

static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index 12f146f..55f2e4e 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -94,6 +94,10 @@ int gpiod_to_irq(const struct gpio_desc *desc);
struct gpio_desc *gpio_to_desc(unsigned gpio);
int desc_to_gpio(const struct gpio_desc *desc);

+struct restrack_desc;
+struct restrack_desc *gpiod_restrack_desc(struct gpio_desc **gpiod,
+ const char *con_id, enum gpiod_flags flags);
+
#else /* CONFIG_GPIOLIB */

static inline struct gpio_desc *__must_check __gpiod_get(struct device *dev,
diff --git a/include/linux/restrack.h b/include/linux/restrack.h
index 4e4eec6..e1aded0 100644
--- a/include/linux/restrack.h
+++ b/include/linux/restrack.h
@@ -5,6 +5,7 @@

#define RESTRACK_TYPE_DRM_PANEL 1
#define RESTRACK_TYPE_REGULATOR 2
+#define RESTRACK_TYPE_GPIO 3

struct device;
struct restrack_ctx;
--
1.9.1

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