[PATCH u-boot v2019.04-aspeed-openbmc v4 3/6] gpio: fixes for gpio-hog support
Eddie James
eajames at linux.ibm.com
Tue Feb 8 10:13:31 AEDT 2022
From: Heiko Schocher <hs at denx.de>
recently added gpio hog patch was "in discussion"
state with Simon Glass. This patch now adds most
of comments from Simon Glass.
(cherry-picked from 49b10cb4926285b856b207c1f5bb40c75487f08b)
Signed-off-by: Heiko Schocher <hs at denx.de>
Signed-off-by: Eddie James <eajames at linux.ibm.com>
---
common/board_r.c | 4 +-
doc/device-tree-bindings/gpio/gpio.txt | 17 ++--
drivers/gpio/Kconfig | 2 +-
drivers/gpio/gpio-uclass.c | 103 ++++++++++++++++++-------
include/asm-generic/gpio.h | 12 +--
5 files changed, 96 insertions(+), 42 deletions(-)
diff --git a/common/board_r.c b/common/board_r.c
index 5bb8f88bd0..429b9a2833 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -48,7 +48,7 @@
#include <linux/compiler.h>
#include <linux/err.h>
#include <efi_loader.h>
-#if defined(CONFIG_DM_GPIO_HOG)
+#if defined(CONFIG_GPIO_HOG)
#include <asm/gpio.h>
#endif
@@ -788,7 +788,7 @@ 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 e774439369..e146917ff3 100644
--- 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 56ed37c2b5..a8dc16ca0e 100644
--- 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 308d0863ad..01cfa2f788 100644
--- 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 37f71e5708..d6cf18744f 100644
--- 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,
--
2.27.0
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