gpio: fixes for gpio-hog support

recently added gpio hog patch was "in discussion"
state with Simon Glass. This patch now adds most
of comments from Simon Glass.

Signed-off-by: Heiko Schocher <hs@denx.de>

diff --git a/common/board_r.c b/common/board_r.c
index ee4dcedd5fa97973c679dc721900111b89bbc498..84aec7fc71cf5203dc3ae28c65f068a46a8bab8e 100644 (file)
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -49,7 +49,7 @@
 #include <linux/err.h>
 #include <efi_loader.h>
 #include <wdt.h>
-#if defined(CONFIG_DM_GPIO_HOG)
+#if defined(CONFIG_GPIO_HOG)
 #include <asm/gpio.h>
 #endif
 
@@ -799,7 +799,7 @@ static init_fnc_t init_sequence_r[] = {
 #ifdef CONFIG_CMD_NET
        initr_ethaddr,
 #endif
-#if defined(CONFIG_DM_GPIO_HOG)
+#if defined(CONFIG_GPIO_HOG)
        gpio_hog_probe_all,
 #endif
 #ifdef CONFIG_BOARD_LATE_INIT

diff --git a/doc/device-tree-bindings/gpio/gpio.txt b/doc/device-tree-bindings/gpio/gpio.txt
index e7744393697217ff2cccaae8faa74fb7ef87da11..e146917ff3342674ebe30b9a50be0df367a2ae22 100644 (file)
--- a/doc/device-tree-bindings/gpio/gpio.txt
+++ b/doc/device-tree-bindings/gpio/gpio.txt
@@ -252,6 +252,7 @@ Example:
                 boot_rescue {
                         gpio-hog;
                         input;
+                        line-name = "foo-bar-gpio";
                         gpios = <7 GPIO_ACTIVE_LOW>;
                 };
         };
@@ -259,9 +260,13 @@ Example:
 For the above Example you can than access the gpio in your boardcode
 with:
 
-        desc = gpio_hog_lookup_name("boot_rescue.gpio-hog");
-        if (desc) {
-                if (dm_gpio_get_value(desc))
-                        printf("\nBooting into Rescue System\n");
-               else
-                       printf("\nBoot normal\n");
+       struct gpio_desc *desc;
+       int ret;
+
+       ret = gpio_hog_lookup_name("boot_rescue", &desc);
+       if (ret)
+               return;
+       if (dm_gpio_get_value(desc) == 1)
+               printf("\nBooting into Rescue System\n");
+       else if (dm_gpio_get_value(desc) == 0)
+               printf("\nBoot normal\n");

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 800584f5122ccaa782645d6375d1d40742625e28..7d9c97f53799ca92e4cf96783e4f8d3bcde3c556 100644 (file)
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -14,7 +14,7 @@ config DM_GPIO
          particular GPIOs that they provide. The uclass interface
          is defined in include/asm-generic/gpio.h.
 
-config DM_GPIO_HOG
+config GPIO_HOG
        bool "Enable GPIO hog support"
        depends on DM_GPIO
        default n

diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 308d0863ada30a1ca1dc83004e0bcd003b6eac75..01cfa2f7884884d0a6c61674da5992f2e7a04555 100644 (file)
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -144,7 +144,7 @@ static int gpio_find_and_xlate(struct gpio_desc *desc,
                return gpio_xlate_offs_flags(desc->dev, desc, args);
 }
 
-#if defined(CONFIG_DM_GPIO_HOG)
+#if defined(CONFIG_GPIO_HOG)
 
 struct gpio_hog_priv {
        struct gpio_desc gpiod;
@@ -181,9 +181,8 @@ static int gpio_hog_ofdata_to_platdata(struct udevice *dev)
                return ret;
        }
        nodename = dev_read_string(dev, "line-name");
-       if (!nodename)
-               nodename = dev_read_name(dev);
-       device_set_name(dev, nodename);
+       if (nodename)
+               device_set_name(dev, nodename);
 
        return 0;
 }
@@ -202,9 +201,15 @@ static int gpio_hog_probe(struct udevice *dev)
                      dev->name);
                return ret;
        }
-       dm_gpio_set_dir(&priv->gpiod);
-       if (plat->gpiod_flags == GPIOD_IS_OUT)
-               dm_gpio_set_value(&priv->gpiod, plat->value);
+
+       if (plat->gpiod_flags == GPIOD_IS_OUT) {
+               ret = dm_gpio_set_value(&priv->gpiod, plat->value);
+               if (ret < 0) {
+                       debug("%s: node %s could not set gpio.\n", __func__,
+                             dev->name);
+                       return ret;
+               }
+       }
 
        return 0;
 }
@@ -213,32 +218,38 @@ int gpio_hog_probe_all(void)
 {
        struct udevice *dev;
        int ret;
+       int retval = 0;
 
        for (uclass_first_device(UCLASS_NOP, &dev);
             dev;
             uclass_find_next_device(&dev)) {
                if (dev->driver == DM_GET_DRIVER(gpio_hog)) {
                        ret = device_probe(dev);
-                       if (ret)
-                               return ret;
+                       if (ret) {
+                               printf("Failed to probe device %s err: %d\n",
+                                      dev->name, ret);
+                               retval = ret;
+                       }
                }
        }
 
-       return 0;
+       return retval;
 }
 
-struct gpio_desc *gpio_hog_lookup_name(const char *name)
+int gpio_hog_lookup_name(const char *name, struct gpio_desc **desc)
 {
        struct udevice *dev;
 
+       *desc = NULL;
        gpio_hog_probe_all();
        if (!uclass_get_device_by_name(UCLASS_NOP, name, &dev)) {
                struct gpio_hog_priv *priv = dev_get_priv(dev);
 
-               return &priv->gpiod;
+               *desc = &priv->gpiod;
+               return 0;
        }
 
-       return NULL;
+       return -ENODEV;
 }
 
 U_BOOT_DRIVER(gpio_hog) = {
@@ -250,9 +261,9 @@ U_BOOT_DRIVER(gpio_hog) = {
        .platdata_auto_alloc_size = sizeof(struct gpio_hog_data),
 };
 #else
-struct gpio_desc *gpio_hog_lookup_name(const char *name)
+int gpio_hog_lookup_name(const char *name, struct gpio_desc **desc)
 {
-       return NULL;
+       return 0;
 }
 #endif
 
@@ -755,13 +766,45 @@ int dm_gpio_get_values_as_int(const struct gpio_desc *desc_list, int count)
        return vector;
 }
 
+/**
+ * gpio_request_tail: common work for requesting a gpio.
+ *
+ * ret:                return value from previous work in function which calls
+ *             this function.
+ *             This seems bogus (why calling this function instead not
+ *             calling it and end caller function instead?).
+ *             Because on error in caller function we want to set some
+ *             default values in gpio desc and have a common error
+ *             debug message, which provides this function.
+ * nodename:   Name of node for which gpio gets requested
+ *             used for gpio label name.
+ * args:       pointer to output arguments structure
+ * list_name:  Name of GPIO list
+ *             used for gpio label name.
+ * index:      gpio index in gpio list
+ *             used for gpio label name.
+ * desc:       pointer to gpio descriptor, filled from this
+ *             function.
+ * flags:      gpio flags to use.
+ * add_index:  should index added to gpio label name
+ * gpio_dev:   pointer to gpio device from which the gpio
+ *             will be requested. If NULL try to get the
+ *             gpio device with uclass_get_device_by_ofnode()
+ *
+ * return:     In error case this function sets default values in
+ *             gpio descriptor, also emmits a debug message.
+ *             On success it returns 0 else the error code from
+ *             function calls, or the error code passed through
+ *             ret to this function.
+ *
+ */
 static int gpio_request_tail(int ret, const char *nodename,
                             struct ofnode_phandle_args *args,
                             const char *list_name, int index,
                             struct gpio_desc *desc, int flags,
-                            bool add_index, struct udevice *dev)
+                            bool add_index, struct udevice *gpio_dev)
 {
-       desc->dev = dev;
+       desc->dev = gpio_dev;
        desc->offset = 0;
        desc->flags = 0;
        if (ret)
@@ -771,7 +814,8 @@ static int gpio_request_tail(int ret, const char *nodename,
                ret = uclass_get_device_by_ofnode(UCLASS_GPIO, args->node,
                                                  &desc->dev);
                if (ret) {
-                       debug("%s: uclass_get_device_by_ofnode failed\n", __func__);
+                       debug("%s: uclass_get_device_by_ofnode failed\n",
+                             __func__);
                        goto err;
                }
        }
@@ -989,10 +1033,8 @@ int gpio_dev_request_index(struct udevice *dev, const char *nodename,
 
 static int gpio_post_bind(struct udevice *dev)
 {
-#if defined(CONFIG_DM_GPIO_HOG)
        struct udevice *child;
        ofnode node;
-#endif
 
 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
        struct dm_gpio_ops *ops = (struct dm_gpio_ops *)device_get_ops(dev);
@@ -1024,16 +1066,21 @@ static int gpio_post_bind(struct udevice *dev)
        }
 #endif
 
-#if defined(CONFIG_DM_GPIO_HOG)
-       dev_for_each_subnode(node, dev) {
-               if (ofnode_read_bool(node, "gpio-hog")) {
-                       const char *name = ofnode_get_name(node);
-
-                       device_bind_driver_to_node(dev, "gpio_hog", name,
-                                                  node, &child);
+       if (IS_ENABLED(CONFIG_GPIO_HOG)) {
+               dev_for_each_subnode(node, dev) {
+                       if (ofnode_read_bool(node, "gpio-hog")) {
+                               const char *name = ofnode_get_name(node);
+                               int ret;
+
+                               ret = device_bind_driver_to_node(dev,
+                                                                "gpio_hog",
+                                                                name, node,
+                                                                &child);
+                               if (ret)
+                                       return ret;
+                       }
                }
        }
-#endif
        return 0;
 }
 

diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 37f71e5708ed533d8d18aa5e897769ea38b8c17b..d6cf18744fda47e2103a597677c9bf560c00022f 100644 (file)
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -352,9 +352,10 @@ int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc);
  * gpio_hog_lookup_name() - Look up a named GPIO and return the gpio descr.
  *
  * @name:      Name to look up
- * @return:    Returns gpio_desc for gpio
+ * @desc:      Returns GPIO description, on success, else NULL
+ * @return:    Returns 0 if OK, else -ENODEV
  */
-struct gpio_desc *gpio_hog_lookup_name(const char *name);
+int gpio_hog_lookup_name(const char *name, struct gpio_desc **desc);
 
 /**
  * gpio_hog_probe_all() - probe all gpio devices with
@@ -523,12 +524,13 @@ int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
  * gpio_dev_request_index() - request single GPIO from gpio device
  *
  * @dev:       GPIO device
- * @nodename:  Name of node
+ * @nodename:  Name of node for which gpio gets requested, used
+ *             for the gpio label name
  * @list_name: Name of GPIO list (e.g. "board-id-gpios")
  * @index:     Index number of the GPIO in that list use request (0=first)
  * @flags:     GPIOD_* flags
- * @dtflags:   GPIO flags read from DT
- * @desc:      GPIO descriotor filled from this function
+ * @dtflags:   GPIO flags read from DT defined see GPIOD_*
+ * @desc:      returns GPIO descriptor filled from this function
  * @return:    return value from gpio_request_tail()
  */
 int gpio_dev_request_index(struct udevice *dev, const char *nodename,