From e29482e8487954c87dc7b4fdbc53574bf1d4cce2 Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Fri, 30 Nov 2012 12:37:36 +0100 Subject: [PATCH 1/2] gpio / ACPI: add ACPI support Add support for translating ACPI GPIO pin numbers to Linux GPIO API pins. Needs a gpio controller driver with the acpi handler hook set. Drivers can use acpi_get_gpio() to translate ACPI5 GpioIO and GpioInt resources to Linux GPIO's. Signed-off-by: Mathias Nyman Signed-off-by: Mika Westerberg Acked-by: Grant Likely Signed-off-by: Rafael J. Wysocki --- drivers/gpio/Kconfig | 4 +++ drivers/gpio/Makefile | 1 + drivers/gpio/gpiolib-acpi.c | 54 +++++++++++++++++++++++++++++++++++++ include/linux/acpi_gpio.h | 19 +++++++++++++ 4 files changed, 78 insertions(+) create mode 100644 drivers/gpio/gpiolib-acpi.c create mode 100644 include/linux/acpi_gpio.h diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index f11d8e3b4041..5c9b384119b8 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -49,6 +49,10 @@ config OF_GPIO def_bool y depends on OF +config GPIO_ACPI + def_bool y + depends on ACPI + config DEBUG_GPIO bool "Debug GPIO calls" depends on DEBUG_KERNEL diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 9aeed6707326..420dbaca05f1 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -4,6 +4,7 @@ ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG obj-$(CONFIG_GPIOLIB) += gpiolib.o devres.o obj-$(CONFIG_OF_GPIO) += gpiolib-of.o +obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o # Device drivers. Generally keep list sorted alphabetically obj-$(CONFIG_GPIO_GENERIC) += gpio-generic.o diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c new file mode 100644 index 000000000000..cbad6e908d30 --- /dev/null +++ b/drivers/gpio/gpiolib-acpi.c @@ -0,0 +1,54 @@ +/* + * ACPI helpers for GPIO API + * + * Copyright (C) 2012, Intel Corporation + * Authors: Mathias Nyman + * Mika Westerberg + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include + +static int acpi_gpiochip_find(struct gpio_chip *gc, void *data) +{ + if (!gc->dev) + return false; + + return ACPI_HANDLE(gc->dev) == data; +} + +/** + * acpi_get_gpio() - Translate ACPI GPIO pin to GPIO number usable with GPIO API + * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1") + * @pin: ACPI GPIO pin number (0-based, controller-relative) + * + * Returns GPIO number to use with Linux generic GPIO API, or errno error value + */ + +int acpi_get_gpio(char *path, int pin) +{ + struct gpio_chip *chip; + acpi_handle handle; + acpi_status status; + + status = acpi_get_handle(NULL, path, &handle); + if (ACPI_FAILURE(status)) + return -ENODEV; + + chip = gpiochip_find(handle, acpi_gpiochip_find); + if (!chip) + return -ENODEV; + + if (!gpio_is_valid(chip->base + pin)) + return -EINVAL; + + return chip->base + pin; +} +EXPORT_SYMBOL_GPL(acpi_get_gpio); diff --git a/include/linux/acpi_gpio.h b/include/linux/acpi_gpio.h new file mode 100644 index 000000000000..91615a389b65 --- /dev/null +++ b/include/linux/acpi_gpio.h @@ -0,0 +1,19 @@ +#ifndef _LINUX_ACPI_GPIO_H_ +#define _LINUX_ACPI_GPIO_H_ + +#include + +#ifdef CONFIG_GPIO_ACPI + +int acpi_get_gpio(char *path, int pin); + +#else /* CONFIG_GPIO_ACPI */ + +static inline int acpi_get_gpio(char *path, int pin) +{ + return -ENODEV; +} + +#endif /* CONFIG_GPIO_ACPI */ + +#endif /* _LINUX_ACPI_GPIO_H_ */ From 64bee4d28c9e2296f4f12a6c4cc40d085c2c9534 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Fri, 30 Nov 2012 12:37:53 +0100 Subject: [PATCH 2/2] spi / ACPI: add ACPI enumeration support ACPI 5 introduced SPISerialBus resource that allows us to enumerate and configure the SPI slave devices behind the SPI controller. This patch adds support for this to the SPI core. In addition we bind ACPI nodes to SPI devices. This makes it possible for the slave drivers to get the ACPI handle for further configuration. Signed-off-by: Mika Westerberg Acked-by: Grant Likely Signed-off-by: Rafael J. Wysocki --- drivers/spi/spi.c | 103 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 102 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 84c2861d6f4d..1ab05234729f 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -35,6 +35,8 @@ #include #include #include +#include +#include static void spidev_release(struct device *dev) { @@ -93,6 +95,10 @@ static int spi_match_device(struct device *dev, struct device_driver *drv) if (of_driver_match_device(dev, drv)) return 1; + /* Then try ACPI */ + if (acpi_driver_match_device(dev, drv)) + return 1; + if (sdrv->id_table) return !!spi_match_id(sdrv->id_table, spi); @@ -888,6 +894,100 @@ static void of_register_spi_devices(struct spi_master *master) static void of_register_spi_devices(struct spi_master *master) { } #endif +#ifdef CONFIG_ACPI +static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) +{ + struct spi_device *spi = data; + + if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { + struct acpi_resource_spi_serialbus *sb; + + sb = &ares->data.spi_serial_bus; + if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { + spi->chip_select = sb->device_selection; + spi->max_speed_hz = sb->connection_speed; + + if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) + spi->mode |= SPI_CPHA; + if (sb->clock_polarity == ACPI_SPI_START_HIGH) + spi->mode |= SPI_CPOL; + if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) + spi->mode |= SPI_CS_HIGH; + } + } else if (spi->irq < 0) { + struct resource r; + + if (acpi_dev_resource_interrupt(ares, 0, &r)) + spi->irq = r.start; + } + + /* Always tell the ACPI core to skip this resource */ + return 1; +} + +static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, + void *data, void **return_value) +{ + struct spi_master *master = data; + struct list_head resource_list; + struct acpi_device *adev; + struct spi_device *spi; + int ret; + + if (acpi_bus_get_device(handle, &adev)) + return AE_OK; + if (acpi_bus_get_status(adev) || !adev->status.present) + return AE_OK; + + spi = spi_alloc_device(master); + if (!spi) { + dev_err(&master->dev, "failed to allocate SPI device for %s\n", + dev_name(&adev->dev)); + return AE_NO_MEMORY; + } + + ACPI_HANDLE_SET(&spi->dev, handle); + spi->irq = -1; + + INIT_LIST_HEAD(&resource_list); + ret = acpi_dev_get_resources(adev, &resource_list, + acpi_spi_add_resource, spi); + acpi_dev_free_resource_list(&resource_list); + + if (ret < 0 || !spi->max_speed_hz) { + spi_dev_put(spi); + return AE_OK; + } + + strlcpy(spi->modalias, dev_name(&adev->dev), sizeof(spi->modalias)); + if (spi_add_device(spi)) { + dev_err(&master->dev, "failed to add SPI device %s from ACPI\n", + dev_name(&adev->dev)); + spi_dev_put(spi); + } + + return AE_OK; +} + +static void acpi_register_spi_devices(struct spi_master *master) +{ + acpi_status status; + acpi_handle handle; + + handle = ACPI_HANDLE(&master->dev); + if (!handle) + return; + + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, + acpi_spi_add_device, NULL, + master, NULL); + if (ACPI_FAILURE(status)) + dev_warn(&master->dev, "failed to enumerate SPI slaves\n"); +} +#else +static inline void acpi_register_spi_devices(struct spi_master *master) {} +#endif /* CONFIG_ACPI */ + static void spi_master_release(struct device *dev) { struct spi_master *master; @@ -1023,8 +1123,9 @@ int spi_register_master(struct spi_master *master) spi_match_master_to_boardinfo(master, &bi->board_info); mutex_unlock(&board_lock); - /* Register devices from the device tree */ + /* Register devices from the device tree and ACPI */ of_register_spi_devices(master); + acpi_register_spi_devices(master); done: return status; }