diff options
40 files changed, 1859 insertions, 447 deletions
diff --git a/Documentation/admin-guide/gpio/gpio-aggregator.rst b/Documentation/admin-guide/gpio/gpio-aggregator.rst new file mode 100644 index 000000000000..5cd1e7221756 --- /dev/null +++ b/Documentation/admin-guide/gpio/gpio-aggregator.rst @@ -0,0 +1,111 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +GPIO Aggregator +=============== + +The GPIO Aggregator provides a mechanism to aggregate GPIOs, and expose them as +a new gpio_chip. This supports the following use cases. + + +Aggregating GPIOs using Sysfs +----------------------------- + +GPIO controllers are exported to userspace using /dev/gpiochip* character +devices. Access control to these devices is provided by standard UNIX file +system permissions, on an all-or-nothing basis: either a GPIO controller is +accessible for a user, or it is not. + +The GPIO Aggregator provides access control for a set of one or more GPIOs, by +aggregating them into a new gpio_chip, which can be assigned to a group or user +using standard UNIX file ownership and permissions. Furthermore, this +simplifies and hardens exporting GPIOs to a virtual machine, as the VM can just +grab the full GPIO controller, and no longer needs to care about which GPIOs to +grab and which not, reducing the attack surface. + +Aggregated GPIO controllers are instantiated and destroyed by writing to +write-only attribute files in sysfs. + + /sys/bus/platform/drivers/gpio-aggregator/ + + "new_device" ... + Userspace may ask the kernel to instantiate an aggregated GPIO + controller by writing a string describing the GPIOs to + aggregate to the "new_device" file, using the format + + .. code-block:: none + + [<gpioA>] [<gpiochipB> <offsets>] ... + + Where: + + "<gpioA>" ... + is a GPIO line name, + + "<gpiochipB>" ... + is a GPIO chip label, and + + "<offsets>" ... + is a comma-separated list of GPIO offsets and/or + GPIO offset ranges denoted by dashes. + + Example: Instantiate a new GPIO aggregator by aggregating GPIO + line 19 of "e6052000.gpio" and GPIO lines 20-21 of + "e6050000.gpio" into a new gpio_chip: + + .. code-block:: sh + + $ echo 'e6052000.gpio 19 e6050000.gpio 20-21' > new_device + + "delete_device" ... + Userspace may ask the kernel to destroy an aggregated GPIO + controller after use by writing its device name to the + "delete_device" file. + + Example: Destroy the previously-created aggregated GPIO + controller, assumed to be "gpio-aggregator.0": + + .. code-block:: sh + + $ echo gpio-aggregator.0 > delete_device + + +Generic GPIO Driver +------------------- + +The GPIO Aggregator can also be used as a generic driver for a simple +GPIO-operated device described in DT, without a dedicated in-kernel driver. +This is useful in industrial control, and is not unlike e.g. spidev, which +allows the user to communicate with an SPI device from userspace. + +Binding a device to the GPIO Aggregator is performed either by modifying the +gpio-aggregator driver, or by writing to the "driver_override" file in Sysfs. + +Example: If "door" is a GPIO-operated device described in DT, using its own +compatible value:: + + door { + compatible = "myvendor,mydoor"; + + gpios = <&gpio2 19 GPIO_ACTIVE_HIGH>, + <&gpio2 20 GPIO_ACTIVE_LOW>; + gpio-line-names = "open", "lock"; + }; + +it can be bound to the GPIO Aggregator by either: + +1. Adding its compatible value to ``gpio_aggregator_dt_ids[]``, +2. Binding manually using "driver_override": + +.. code-block:: sh + + $ echo gpio-aggregator > /sys/bus/platform/devices/door/driver_override + $ echo door > /sys/bus/platform/drivers/gpio-aggregator/bind + +After that, a new gpiochip "door" has been created: + +.. code-block:: sh + + $ gpioinfo door + gpiochip12 - 2 lines: + line 0: "open" unused input active-high + line 1: "lock" unused input active-high diff --git a/Documentation/admin-guide/gpio/index.rst b/Documentation/admin-guide/gpio/index.rst index a244ba4e87d5..ef2838638e96 100644 --- a/Documentation/admin-guide/gpio/index.rst +++ b/Documentation/admin-guide/gpio/index.rst @@ -7,6 +7,7 @@ gpio .. toctree:: :maxdepth: 1 + gpio-aggregator sysfs .. only:: subproject and html diff --git a/Documentation/devicetree/bindings/gpio/renesas,em-gio.yaml b/Documentation/devicetree/bindings/gpio/renesas,em-gio.yaml new file mode 100644 index 000000000000..8bdef812c87c --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/renesas,em-gio.yaml @@ -0,0 +1,70 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gpio/renesas,em-gio.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Renesas EMMA Mobile General Purpose I/O Interface + +maintainers: + - Magnus Damm <magnus.damm@gmail.com> + +properties: + compatible: + const: renesas,em-gio + + reg: + items: + - description: First set of contiguous registers + - description: Second set of contiguous registers + + interrupts: + items: + - description: Interrupt for the first set of 16 GPIO ports + - description: Interrupt for the second set of 16 GPIO ports + + gpio-controller: true + + '#gpio-cells': + const: 2 + + gpio-ranges: + maxItems: 1 + + ngpios: + minimum: 1 + maximum: 32 + + interrupt-controller: true + + '#interrupt-cells': + const: 2 + +required: + - compatible + - reg + - interrupts + - gpio-controller + - '#gpio-cells' + - gpio-ranges + - ngpios + - interrupt-controller + - '#interrupt-cells' + +additionalProperties: false + +examples: + - | + #include <dt-bindings/interrupt-controller/arm-gic.h> + gpio0: gpio@e0050000 { + compatible = "renesas,em-gio"; + reg = <0xe0050000 0x2c>, <0xe0050040 0x20>; + interrupts = <GIC_SPI 67 IRQ_TYPE_LEVEL_HIGH>, + <GIC_SPI 68 IRQ_TYPE_LEVEL_HIGH>; + gpio-controller; + #gpio-cells = <2>; + gpio-ranges = <&pfc 0 0 32>; + ngpios = <32>; + interrupt-controller; + #interrupt-cells = <2>; + }; diff --git a/Documentation/devicetree/bindings/gpio/snps,dw-apb-gpio.yaml b/Documentation/devicetree/bindings/gpio/snps,dw-apb-gpio.yaml new file mode 100644 index 000000000000..04a3c51e1dc1 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/snps,dw-apb-gpio.yaml @@ -0,0 +1,134 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gpio/snps,dw-apb-gpio.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Synopsys DesignWare APB GPIO controller + +description: | + Synopsys DesignWare GPIO controllers have a configurable number of ports, + each of which are intended to be represented as child nodes with the generic + GPIO-controller properties as desribed in this bindings file. + +maintainers: + - Hoan Tran <hoan@os.amperecomputing.com> + - Serge Semin <fancer.lancer@gmail.com> + +properties: + $nodename: + pattern: "^gpio@[0-9a-f]+$" + + compatible: + const: snps,dw-apb-gpio + + "#address-cells": + const: 1 + + "#size-cells": + const: 0 + + reg: + maxItems: 1 + + clocks: + minItems: 1 + items: + - description: APB interface clock source + - description: DW GPIO debounce reference clock source + + clock-names: + minItems: 1 + items: + - const: bus + - const: db + + resets: + maxItems: 1 + +patternProperties: + "^gpio-(port|controller)@[0-9a-f]+$": + type: object + properties: + compatible: + const: snps,dw-apb-gpio-port + + reg: + maxItems: 1 + + gpio-controller: true + + '#gpio-cells': + const: 2 + + snps,nr-gpios: + description: The number of GPIO pins exported by the port. + default: 32 + allOf: + - $ref: /schemas/types.yaml#/definitions/uint32 + - minimum: 1 + maximum: 32 + + interrupts: + description: | + The interrupts to the parent controller raised when GPIOs generate + the interrupts. If the controller provides one combined interrupt + for all GPIOs, specify a single interrupt. If the controller provides + one interrupt for each GPIO, provide a list of interrupts that + correspond to each of the GPIO pins. + minItems: 1 + maxItems: 32 + + interrupt-controller: true + + '#interrupt-cells': + const: 2 + + required: + - compatible + - reg + - gpio-controller + - '#gpio-cells' + + dependencies: + interrupt-controller: [ interrupts ] + + additionalProperties: false + +additionalProperties: false + +required: + - compatible + - reg + - "#address-cells" + - "#size-cells" + +examples: + - | + gpio: gpio@20000 { + compatible = "snps,dw-apb-gpio"; + reg = <0x20000 0x1000>; + #address-cells = <1>; + #size-cells = <0>; + + porta: gpio-port@0 { + compatible = "snps,dw-apb-gpio-port"; + reg = <0>; + gpio-controller; + #gpio-cells = <2>; + snps,nr-gpios = <8>; + interrupt-controller; + #interrupt-cells = <2>; + interrupt-parent = <&vic1>; + interrupts = <0>; + }; + + portb: gpio-port@1 { + compatible = "snps,dw-apb-gpio-port"; + reg = <1>; + gpio-controller; + #gpio-cells = <2>; + snps,nr-gpios = <8>; + }; + }; +... diff --git a/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt b/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt deleted file mode 100644 index 839dd32ffe11..000000000000 --- a/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt +++ /dev/null @@ -1,65 +0,0 @@ -* Synopsys DesignWare APB GPIO controller - -Required properties: -- compatible : Should contain "snps,dw-apb-gpio" -- reg : Address and length of the register set for the device. -- #address-cells : should be 1 (for addressing port subnodes). -- #size-cells : should be 0 (port subnodes). - -The GPIO controller has a configurable number of ports, each of which are -represented as child nodes with the following properties: - -Required properties: -- compatible : "snps,dw-apb-gpio-port" -- gpio-controller : Marks the device node as a gpio controller. -- #gpio-cells : Should be two. The first cell is the pin number and - the second cell is used to specify the gpio polarity: - 0 = active high - 1 = active low -- reg : The integer port index of the port, a single cell. - -Optional properties: -- interrupt-controller : The first port may be configured to be an interrupt -controller. -- #interrupt-cells : Specifies the number of cells needed to encode an - interrupt. Shall be set to 2. The first cell defines the interrupt number, - the second encodes the triger flags encoded as described in - Documentation/devicetree/bindings/interrupt-controller/interrupts.txt -- interrupts : The interrupts to the parent controller raised when GPIOs - generate the interrupts. If the controller provides one combined interrupt - for all GPIOs, specify a single interrupt. If the controller provides one - interrupt for each GPIO, provide a list of interrupts that correspond to each - of the GPIO pins. When specifying multiple interrupts, if any are unconnected, - use the interrupts-extended property to specify the interrupts and set the - interrupt controller handle for unused interrupts to 0. -- snps,nr-gpios : The number of pins in the port, a single cell. -- resets : Reset line for the controller. - -Example: - -gpio: gpio@20000 { - compatible = "snps,dw-apb-gpio"; - reg = <0x20000 0x1000>; - #address-cells = <1>; - #size-cells = <0>; - - porta: gpio@0 { - compatible = "snps,dw-apb-gpio-port"; - gpio-controller; - #gpio-cells = <2>; - snps,nr-gpios = <8>; - reg = <0>; - interrupt-controller; - #interrupt-cells = <2>; - interrupt-parent = <&vic1>; - interrupts = <0>; - }; - - portb: gpio@1 { - compatible = "snps,dw-apb-gpio-port"; - gpio-controller; - #gpio-cells = <2>; - snps,nr-gpios = <8>; - reg = <1>; - }; -}; diff --git a/Documentation/driver-api/gpio/board.rst b/Documentation/driver-api/gpio/board.rst index ce91518bf9f4..191fa867826a 100644 --- a/Documentation/driver-api/gpio/board.rst +++ b/Documentation/driver-api/gpio/board.rst @@ -113,13 +113,15 @@ files that desire to do so need to include the following header:: GPIOs are mapped by the means of tables of lookups, containing instances of the gpiod_lookup structure. Two macros are defined to help declaring such mappings:: - GPIO_LOOKUP(chip_label, chip_hwnum, con_id, flags) - GPIO_LOOKUP_IDX(chip_label, chip_hwnum, con_id, idx, flags) + GPIO_LOOKUP(key, chip_hwnum, con_id, flags) + GPIO_LOOKUP_IDX(key, chip_hwnum, con_id, idx, flags) where - - chip_label is the label of the gpiod_chip instance providing the GPIO - - chip_hwnum is the hardware number of the GPIO within the chip + - key is either the label of the gpiod_chip instance providing the GPIO, or + the GPIO line name + - chip_hwnum is the hardware number of the GPIO within the chip, or U16_MAX + to indicate that key is a GPIO line name - con_id is the name of the GPIO function from the device point of view. It can be NULL, in which case it will match any function. - idx is the index of the GPIO within the function. @@ -135,7 +137,10 @@ where In the future, these flags might be extended to support more properties. -Note that GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0. +Note that: + 1. GPIO line names are not guaranteed to be globally unique, so the first + match found will be used. + 2. GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0. A lookup table can then be defined as follows, with an empty entry defining its end. The 'dev_id' field of the table is the identifier of the device that will diff --git a/MAINTAINERS b/MAINTAINERS index 49955212a803..c0d5ddd655ea 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7283,6 +7283,13 @@ F: Documentation/firmware-guide/acpi/gpio-properties.rst F: drivers/gpio/gpiolib-acpi.c F: drivers/gpio/gpiolib-acpi.h +GPIO AGGREGATOR +M: Geert Uytterhoeven <geert+renesas@glider.be> +L: linux-gpio@vger.kernel.org +S: Supported +F: Documentation/admin-guide/gpio/gpio-aggregator.rst +F: drivers/gpio/gpio-aggregator.c + GPIO IR Transmitter M: Sean Young <sean@mess.org> L: linux-media@vger.kernel.org @@ -7296,6 +7303,12 @@ S: Maintained F: drivers/gpio/gpio-mockup.c F: tools/testing/selftests/gpio/ +GPIO REGMAP +R: Michael Walle <michael@walle.cc> +S: Maintained +F: drivers/gpio/gpio-regmap.c +F: include/linux/gpio/regmap.h + GPIO SUBSYSTEM M: Linus Walleij <linus.walleij@linaro.org> M: Bartosz Golaszewski <bgolaszewski@baylibre.com> @@ -16368,9 +16381,10 @@ F: drivers/tty/serial/8250/8250_lpss.c SYNOPSYS DESIGNWARE APB GPIO DRIVER M: Hoan Tran <hoan@os.amperecomputing.com> +M: Serge Semin <fancer.lancer@gmail.com> L: linux-gpio@vger.kernel.org S: Maintained -F: Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt +F: Documentation/devicetree/bindings/gpio/snps,dw-apb-gpio.yaml F: drivers/gpio/gpio-dwapb.c SYNOPSYS DESIGNWARE AXI DMAC DRIVER diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 1b96169d84f7..bcacd9c74aa8 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -73,6 +73,10 @@ config GPIO_GENERIC depends on HAS_IOMEM # Only for IOMEM drivers tristate +config GPIO_REGMAP + depends on REGMAP + tristate + # put drivers in the right section, in alphabetical order # This symbol is selected by both I2C and SPI expanders @@ -422,7 +426,7 @@ config GPIO_OMAP Say yes here to enable GPIO support for TI OMAP SoCs. config GPIO_PL061 - bool "PrimeCell PL061 GPIO support" + tristate "PrimeCell PL061 GPIO support" depends on ARM_AMBA select IRQ_DOMAIN select GPIOLIB_IRQCHIP @@ -439,7 +443,7 @@ config GPIO_PMIC_EIC_SPRD config GPIO_PXA bool "PXA GPIO support" - depends on ARCH_PXA || ARCH_MMP + depends on ARCH_PXA || ARCH_MMP || COMPILE_TEST help Say yes here to support the PXA GPIO device @@ -638,7 +642,7 @@ config GPIO_XGENE config GPIO_XGENE_SB tristate "APM X-Gene GPIO standby controller support" - depends on ARCH_XGENE && OF_GPIO + depends on (ARCH_XGENE || COMPILE_TEST) select GPIO_GENERIC select GPIOLIB_IRQCHIP select IRQ_DOMAIN_HIERARCHY @@ -952,7 +956,7 @@ config GPIO_PCA953X config GPIO_PCA953X_IRQ bool "Interrupt controller support for PCA953x" - depends on GPIO_PCA953X=y + depends on GPIO_PCA953X select GPIOLIB_IRQCHIP help Say yes here to enable the pca953x to be used as an interrupt @@ -1541,6 +1545,18 @@ config GPIO_VIPERBOARD endmenu +config GPIO_AGGREGATOR + tristate "GPIO Aggregator" + help + Say yes here to enable the GPIO Aggregator, which provides a way to + aggregate existing GPIO lines into a new virtual GPIO chip. + This can serve the following purposes: + - Assign permissions for a collection of GPIO lines to a user, + - Export a collection of GPIO lines to a virtual machine, + - Provide a generic driver for a GPIO-operated device in an + industrial control context, to be operated from userspace using + the GPIO chardev interface. + config GPIO_MOCKUP tristate "GPIO Testing Driver" select IRQ_SIM diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index b2cfc21a97f3..1e4894e0bf0f 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -12,6 +12,7 @@ obj-$(CONFIG_GPIO_SYSFS) += gpiolib-sysfs.o obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o # Device drivers. Generally keep list sorted alphabetically +obj-$(CONFIG_GPIO_REGMAP) += gpio-regmap.o obj-$(CONFIG_GPIO_GENERIC) += gpio-generic.o # directly supported by gpio-generic @@ -25,6 +26,7 @@ obj-$(CONFIG_GPIO_74XX_MMIO) += gpio-74xx-mmio.o obj-$(CONFIG_GPIO_ADNP) += gpio-adnp.o obj-$(CONFIG_GPIO_ADP5520) += gpio-adp5520.o obj-$(CONFIG_GPIO_ADP5588) += gpio-adp5588.o +obj-$(CONFIG_GPIO_AGGREGATOR) += gpio-aggregator.o obj-$(CONFIG_GPIO_ALTERA_A10SR) += gpio-altera-a10sr.o obj-$(CONFIG_GPIO_ALTERA) += gpio-altera.o obj-$(CONFIG_GPIO_AMD8111) += gpio-amd8111.o diff --git a/drivers/gpio/TODO b/drivers/gpio/TODO index 3a44e6ae52bd..b989c9352da2 100644 --- a/drivers/gpio/TODO +++ b/drivers/gpio/TODO @@ -99,6 +99,10 @@ similar and probe a proper driver in the gpiolib subsystem. In some cases it makes sense to create a GPIO chip from the local driver for a few GPIOs. Those should stay where they are. +At the same time it makes sense to get rid of code duplication in existing or +new coming drivers. For example, gpio-ml-ioh should be incorporated into +gpio-pch. In similar way gpio-intel-mid into gpio-pxa. + Generic MMIO GPIO diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c new file mode 100644 index 000000000000..9b0adbdddbfc --- /dev/null +++ b/drivers/gpio/gpio-aggregator.c @@ -0,0 +1,568 @@ +// SPDX-License-Identifier: GPL-2.0-only +// +// GPIO Aggregator +// +// Copyright (C) 2019-2020 Glider bv + +#define DRV_NAME "gpio-aggregator" +#define pr_fmt(fmt) DRV_NAME ": " fmt + +#include <linux/bitmap.h> +#include <linux/bitops.h> +#include <linux/ctype.h> +#include <linux/gpio/consumer.h> +#include <linux/gpio/driver.h> +#include <linux/gpio/machine.h> +#include <linux/idr.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/overflow.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/string.h> + + +/* + * GPIO Aggregator sysfs interface + */ + +struct gpio_aggregator { + struct gpiod_lookup_table *lookups; + struct platform_device *pdev; + char args[]; +}; + +static DEFINE_MUTEX(gpio_aggregator_lock); /* protects idr */ +static DEFINE_IDR(gpio_aggregator_idr); + +static char *get_arg(char **args) +{ + char *start = *args, *end; + + start = skip_spaces(start); + if (!*start) + return NULL; + + if (*start == '"') { + /* Quoted arg */ + end = strchr(++start, '"'); + if (!end) + return ERR_PTR(-EINVAL); + } else { + /* Unquoted arg */ + for (end = start; *end && !isspace(*end); end++) ; + } + + if (*end) + *end++ = '\0'; + + *args = end; + return start; +} + +static bool isrange(const char *s) +{ + size_t n; + + if (IS_ERR_OR_NULL(s)) + return false; + + while (1) { + n = strspn(s, "0123456789"); + if (!n) + return false; + + s += n; + + switch (*s++) { + case '\0': + return true; + + case '-': + case ',': + break; + + default: + return false; + } + } +} + +static int aggr_add_gpio(struct gpio_aggregator *aggr, const char *key, + int hwnum, unsigned int *n) +{ + struct gpiod_lookup_table *lookups; + + lookups = krealloc(aggr->lookups, struct_size(lookups, table, *n + 2), + GFP_KERNEL); + if (!lookups) + return -ENOMEM; + + lookups->table[*n] = + (struct gpiod_lookup)GPIO_LOOKUP_IDX(key, hwnum, NULL, *n, 0); + + (*n)++; + memset(&lookups->table[*n], 0, sizeof(lookups->table[*n])); + + aggr->lookups = lookups; + return 0; +} + +static int aggr_parse(struct gpio_aggregator *aggr) +{ + unsigned int first_index, last_index, i, n = 0; + char *name, *offsets, *first, *last, *next; + char *args = aggr->args; + int error; + + for (name = get_arg(&args), offsets = get_arg(&args); name; + offsets = get_arg(&args)) { + if (IS_ERR(name)) { + pr_err("Cannot get GPIO specifier: %pe\n", name); + return PTR_ERR(name); + } + + if (!isrange(offsets)) { + /* Named GPIO line */ + error = aggr_add_gpio(aggr, name, U16_MAX, &n); + if (error) + return error; + + name = offsets; + continue; + } + + /* GPIO chip + offset(s) */ + for (first = offsets; *first; first = next) { + next = strchrnul(first, ','); + if (*next) + *next++ = '\0'; + + last = strchr(first, '-'); + if (last) + *last++ = '\0'; + + if (kstrtouint(first, 10, &first_index)) { + pr_err("Cannot parse GPIO index %s\n", first); + return -EINVAL; + } + + if (!last) { + last_index = first_index; + } else if (kstrtouint(last, 10, &last_index)) { + pr_err("Cannot parse GPIO index %s\n", last); + return -EINVAL; + } + + for (i = first_index; i <= last_index; i++) { + error = aggr_add_gpio(aggr, name, i, &n); + if (error) + return error; + } + } + + name = get_arg(&args); + } + + if (!n) { + pr_err("No GPIOs specified\n"); + return -EINVAL; + } + + return 0; +} + +static ssize_t new_device_store(struct device_driver *driver, const char *buf, + size_t count) +{ + struct gpio_aggregator *aggr; + struct platform_device *pdev; + int res, id; + + /* kernfs guarantees string termination, so count + 1 is safe */ + aggr = kzalloc(sizeof(*aggr) + count + 1, GFP_KERNEL); + if (!aggr) + return -ENOMEM; + + memcpy(aggr->args, buf, count + 1); + + aggr->lookups = kzalloc(struct_size(aggr->lookups, table, 1), + GFP_KERNEL); + if (!aggr->lookups) { + res = -ENOMEM; + goto free_ga; + } + + mutex_lock(&gpio_aggregator_lock); + id = idr_alloc(&gpio_aggregator_idr, aggr, 0, 0, GFP_KERNEL); + mutex_unlock(&gpio_aggregator_lock); + + if (id < 0) { + res = id; + goto free_table; + } + + aggr->lookups->dev_id = kasprintf(GFP_KERNEL, "%s.%d", DRV_NAME, id); + if (!aggr->lookups->dev_id) { + res = -ENOMEM; + goto remove_idr; + } + + res = aggr_parse(aggr); + if (res) + goto free_dev_id; + + gpiod_add_lookup_table(aggr->lookups); + + pdev = platform_device_register_simple(DRV_NAME, id, NULL, 0); + if (IS_ERR(pdev)) { + res = PTR_ERR(pdev); + goto remove_table; + } + + aggr->pdev = pdev; + return count; + +remove_table: + gpiod_remove_lookup_table(aggr->lookups); +free_dev_id: + kfree(aggr->lookups->dev_id); +remove_idr: + mutex_lock(&gpio_aggregator_lock); + idr_remove(&gpio_aggregator_idr, id); + mutex_unlock(&gpio_aggregator_lock); +free_table: + kfree(aggr->lookups); +free_ga: + kfree(aggr); + return res; +} + +static DRIVER_ATTR_WO(new_device); + +static void gpio_aggregator_free(struct gpio_aggregator *aggr) +{ + platform_device_unregister(aggr->pdev); 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