[PATCH U-Boot v2019.04-aspeed-openbmc 2/6] gpio: add gpio-hog support
Eddie James
eajames at linux.ibm.com
Tue Jan 25 06:14:59 AEDT 2022
From: Heiko Schocher <hs at denx.de>
add gpio-hog support. GPIO hogging is a mechanism
providing automatic GPIO request and configuration
as part of the gpio-controller's driver probe function.
for more infos see:
doc/device-tree-bindings/gpio/gpio.txt
Signed-off-by: Heiko Schocher <hs at denx.de>
Tested-by: Michal Simek <michal.simek at xilinx.com> (zcu102)
Tested-by: Patrick Delaunay <patrick.delaunay at st.com>
---
common/board_r.c | 6 +
doc/device-tree-bindings/gpio/gpio.txt | 55 ++++++++
drivers/gpio/Kconfig | 10 ++
drivers/gpio/gpio-uclass.c | 181 ++++++++++++++++++++++---
include/asm-generic/gpio.h | 32 +++++
5 files changed, 268 insertions(+), 16 deletions(-)
diff --git a/common/board_r.c b/common/board_r.c
index 472987d5d5..5bb8f88bd0 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -48,6 +48,9 @@
#include <linux/compiler.h>
#include <linux/err.h>
#include <efi_loader.h>
+#if defined(CONFIG_DM_GPIO_HOG)
+#include <asm/gpio.h>
+#endif
DECLARE_GLOBAL_DATA_PTR;
@@ -785,6 +788,9 @@ static init_fnc_t init_sequence_r[] = {
#ifdef CONFIG_CMD_NET
initr_ethaddr,
#endif
+#if defined(CONFIG_DM_GPIO_HOG)
+ gpio_hog_probe_all,
+#endif
#ifdef CONFIG_BOARD_LATE_INIT
board_late_init,
#endif
diff --git a/doc/device-tree-bindings/gpio/gpio.txt b/doc/device-tree-bindings/gpio/gpio.txt
index f7a158d858..e774439369 100644
--- a/doc/device-tree-bindings/gpio/gpio.txt
+++ b/doc/device-tree-bindings/gpio/gpio.txt
@@ -210,3 +210,58 @@ Example 2:
Here, three GPIO ranges are defined wrt. two pin controllers. pinctrl1 GPIO
ranges are defined using pin numbers whereas the GPIO ranges wrt. pinctrl2
are named "foo" and "bar".
+
+3) GPIO hog definitions
+-----------------------
+
+The GPIO chip may contain GPIO hog definitions. GPIO hogging is a mechanism
+providing automatic GPIO request and configuration as part of the
+gpio-controller's driver probe function.
+
+Each GPIO hog definition is represented as a child node of the GPIO controller.
+Required properties:
+- gpio-hog: A property specifying that this child node represents a GPIO hog.
+- gpios: Store the GPIO information (id, flags) for the GPIO to
+ affect.
+
+ ! Not yet support more than one gpio !
+
+Only one of the following properties scanned in the order shown below.
+- input: A property specifying to set the GPIO direction as input.
+- output-low A property specifying to set the GPIO direction as output with
+ the value low.
+- output-high A property specifying to set the GPIO direction as output with
+ the value high.
+
+Optional properties:
+- line-name: The GPIO label name. If not present the node name is used.
+
+Example:
+
+ tca6416 at 20 {
+ compatible = "ti,tca6416";
+ reg = <0x20>;
+ #gpio-cells = <2>;
+ gpio-controller;
+
+ env_reset {
+ gpio-hog;
+ input;
+ gpios = <6 GPIO_ACTIVE_LOW>;
+ };
+ boot_rescue {
+ gpio-hog;
+ input;
+ gpios = <7 GPIO_ACTIVE_LOW>;
+ };
+ };
+
+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");
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index a519a0a169..56ed37c2b5 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -14,6 +14,16 @@ config DM_GPIO
particular GPIOs that they provide. The uclass interface
is defined in include/asm-generic/gpio.h.
+config DM_GPIO_HOG
+ bool "Enable GPIO hog support"
+ depends on DM_GPIO
+ default n
+ help
+ Enable gpio hog support
+ The GPIO chip may contain GPIO hog definitions. GPIO hogging
+ is a mechanism providing automatic GPIO request and config-
+ uration as part of the gpio-controller's driver probe function.
+
config ALTERA_PIO
bool "Altera PIO driver"
depends on DM_GPIO
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index da5e9ba6e5..308d0863ad 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -5,6 +5,9 @@
#include <common.h>
#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <dm/uclass-internal.h>
#include <dt-bindings/gpio/gpio.h>
#include <errno.h>
#include <fdtdec.h>
@@ -141,6 +144,118 @@ 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)
+
+struct gpio_hog_priv {
+ struct gpio_desc gpiod;
+};
+
+struct gpio_hog_data {
+ int gpiod_flags;
+ int value;
+ u32 val[2];
+};
+
+static int gpio_hog_ofdata_to_platdata(struct udevice *dev)
+{
+ struct gpio_hog_data *plat = dev_get_platdata(dev);
+ const char *nodename;
+ int ret;
+
+ plat->value = 0;
+ if (dev_read_bool(dev, "input")) {
+ plat->gpiod_flags = GPIOD_IS_IN;
+ } else if (dev_read_bool(dev, "output-high")) {
+ plat->value = 1;
+ plat->gpiod_flags = GPIOD_IS_OUT;
+ } else if (dev_read_bool(dev, "output-low")) {
+ plat->gpiod_flags = GPIOD_IS_OUT;
+ } else {
+ printf("%s: missing gpio-hog state.\n", __func__);
+ return -EINVAL;
+ }
+ ret = dev_read_u32_array(dev, "gpios", plat->val, 2);
+ if (ret) {
+ printf("%s: wrong gpios property, 2 values needed %d\n",
+ __func__, ret);
+ return ret;
+ }
+ nodename = dev_read_string(dev, "line-name");
+ if (!nodename)
+ nodename = dev_read_name(dev);
+ device_set_name(dev, nodename);
+
+ return 0;
+}
+
+static int gpio_hog_probe(struct udevice *dev)
+{
+ struct gpio_hog_data *plat = dev_get_platdata(dev);
+ struct gpio_hog_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ ret = gpio_dev_request_index(dev->parent, dev->name, "gpio-hog",
+ plat->val[0], plat->gpiod_flags,
+ plat->val[1], &priv->gpiod);
+ if (ret < 0) {
+ debug("%s: node %s could not get gpio.\n", __func__,
+ 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);
+
+ return 0;
+}
+
+int gpio_hog_probe_all(void)
+{
+ struct udevice *dev;
+ int ret;
+
+ 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;
+ }
+ }
+
+ return 0;
+}
+
+struct gpio_desc *gpio_hog_lookup_name(const char *name)
+{
+ struct udevice *dev;
+
+ 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;
+ }
+
+ return NULL;
+}
+
+U_BOOT_DRIVER(gpio_hog) = {
+ .name = "gpio_hog",
+ .id = UCLASS_NOP,
+ .ofdata_to_platdata = gpio_hog_ofdata_to_platdata,
+ .probe = gpio_hog_probe,
+ .priv_auto_alloc_size = sizeof(struct gpio_hog_priv),
+ .platdata_auto_alloc_size = sizeof(struct gpio_hog_data),
+};
+#else
+struct gpio_desc *gpio_hog_lookup_name(const char *name)
+{
+ return NULL;
+}
+#endif
+
int dm_gpio_request(struct gpio_desc *desc, const char *label)
{
struct udevice *dev = desc->dev;
@@ -640,22 +755,25 @@ int dm_gpio_get_values_as_int(const struct gpio_desc *desc_list, int count)
return vector;
}
-static int gpio_request_tail(int ret, ofnode node,
+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 gpio_desc *desc, int flags,
+ bool add_index, struct udevice *dev)
{
- desc->dev = NULL;
+ desc->dev = dev;
desc->offset = 0;
desc->flags = 0;
if (ret)
goto err;
- ret = uclass_get_device_by_ofnode(UCLASS_GPIO, args->node,
- &desc->dev);
- if (ret) {
- debug("%s: uclass_get_device_by_ofnode failed\n", __func__);
- goto err;
+ if (!desc->dev) {
+ ret = uclass_get_device_by_ofnode(UCLASS_GPIO, args->node,
+ &desc->dev);
+ if (ret) {
+ debug("%s: uclass_get_device_by_ofnode failed\n", __func__);
+ goto err;
+ }
}
ret = gpio_find_and_xlate(desc, args);
if (ret) {
@@ -663,8 +781,7 @@ static int gpio_request_tail(int ret, ofnode node,
goto err;
}
ret = dm_gpio_requestf(desc, add_index ? "%s.%s%d" : "%s.%s",
- ofnode_get_name(node),
- list_name, index);
+ nodename, list_name, index);
if (ret) {
debug("%s: dm_gpio_requestf failed\n", __func__);
goto err;
@@ -678,7 +795,7 @@ static int gpio_request_tail(int ret, ofnode node,
return 0;
err:
debug("%s: Node '%s', property '%s', failed to request GPIO index %d: %d\n",
- __func__, ofnode_get_name(node), list_name, index, ret);
+ __func__, nodename, list_name, index, ret);
return ret;
}
@@ -692,8 +809,8 @@ static int _gpio_request_by_name_nodev(ofnode node, const char *list_name,
ret = ofnode_parse_phandle_with_args(node, list_name, "#gpio-cells", 0,
index, &args);
- return gpio_request_tail(ret, node, &args, list_name, index, desc,
- flags, add_index);
+ return gpio_request_tail(ret, ofnode_get_name(node), &args, list_name,
+ index, desc, flags, add_index, NULL);
}
int gpio_request_by_name_nodev(ofnode node, const char *list_name, int index,
@@ -707,13 +824,14 @@ int gpio_request_by_name(struct udevice *dev, const char *list_name, int index,
struct gpio_desc *desc, int flags)
{
struct ofnode_phandle_args args;
+ ofnode node;
int ret;
ret = dev_read_phandle_with_args(dev, list_name, "#gpio-cells", 0,
index, &args);
-
- return gpio_request_tail(ret, dev_ofnode(dev), &args, list_name,
- index, desc, flags, index > 0);
+ node = dev_ofnode(dev);
+ return gpio_request_tail(ret, ofnode_get_name(node), &args, list_name,
+ index, desc, flags, index > 0, NULL);
}
int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
@@ -854,8 +972,28 @@ static int gpio_pre_remove(struct udevice *dev)
return gpio_renumber(dev);
}
+int gpio_dev_request_index(struct udevice *dev, const char *nodename,
+ char *list_name, int index, int flags,
+ int dtflags, struct gpio_desc *desc)
+{
+ struct ofnode_phandle_args args;
+
+ args.node = ofnode_null();
+ args.args_count = 2;
+ args.args[0] = index;
+ args.args[1] = dtflags;
+
+ return gpio_request_tail(0, nodename, &args, list_name, index, desc,
+ flags, 0, dev);
+}
+
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);
static int reloc_done;
@@ -885,6 +1023,17 @@ static int gpio_post_bind(struct udevice *dev)
reloc_done++;
}
#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);
+ }
+ }
+#endif
return 0;
}
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index d03602696f..37f71e5708 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -348,6 +348,22 @@ const char *gpio_get_bank_info(struct udevice *dev, int *offset_count);
*/
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
+ */
+struct gpio_desc *gpio_hog_lookup_name(const char *name);
+
+/**
+ * gpio_hog_probe_all() - probe all gpio devices with
+ * gpio-hog subnodes.
+ *
+ * @return: Returns return value from device_probe()
+ */
+int gpio_hog_probe_all(void);
+
/**
* gpio_lookup_name - Look up a GPIO name and return its details
*
@@ -503,6 +519,22 @@ int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
struct gpio_desc *desc_list, int max_count,
int flags);
+/**
+ * gpio_dev_request_index() - request single GPIO from gpio device
+ *
+ * @dev: GPIO device
+ * @nodename: Name of node
+ * @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
+ * @return: return value from gpio_request_tail()
+ */
+int gpio_dev_request_index(struct udevice *dev, const char *nodename,
+ char *list_name, int index, int flags,
+ int dtflags, struct gpio_desc *desc);
+
/**
* dm_gpio_free() - Free a single GPIO
*
--
2.27.0
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