[U-Boot] [PATCH v4] gpio: add gpio-hog support
Michal Simek
michal.simek at xilinx.com
Wed Jun 12 08:13:09 UTC 2019
On 12. 06. 19 6:11, Heiko Schocher wrote:
> 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>
>
> ---
> clean travis build, see result:
> https://travis-ci.org/hsdenx/u-boot-test/builds/544040419
>
> Changes in v4:
> - rework as suggested by Patrick
> based on patch:
> http://patchwork.ozlabs.org/patch/1098913/
> use new UCLASS_NOP
> hog detection + DT parsing in gpio_post_bind() .... info saved in platdata
> gpio configuration for hog (request and set_dir) => probe function
>
> Changes in v3:
> - probe now all gpio devices with gpio-hogs
> from board_r before board_late_init() call
> or if someone wants to access gpio-hog
> based gpios with gpio_hog_lookup_name()
> This is needed, because we cannot be sure,
> if a gpio device which contains gpio-hogs
> is probed.
> - add line-name property as Michal recommended
> - renamed gpio_priv_one into gpio_priv_one_hog
> and protected through CONFIG_DM_GPIO_HOG
>
> Changes in v2:
> - move gpio_hog() call from post_probe() to post_bind()
> call. Check if current gpio device has gpio-hog
> definitions, if so, probe it.
>
> 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 150e8cd424..507da4c74a 100644
> --- a/common/board_r.c
> +++ b/common/board_r.c
> @@ -49,6 +49,9 @@
> #include <linux/err.h>
> #include <efi_loader.h>
> #include <wdt.h>
> +#if defined(CONFIG_DM_GPIO_HOG)
> +#include <asm/gpio.h>
> +#endif
>
> DECLARE_GLOBAL_DATA_PTR;
>
> @@ -796,6 +799,9 @@ 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 e36a8abc42..fa1c99700f 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
> *
>
Tested-by: Michal Simek <michal.simek at xilinx.com> (zcu102)
Thanks,
Michal
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