Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753354Ab2KTNBA (ORCPT ); Tue, 20 Nov 2012 08:01:00 -0500 Received: from ogre.sisk.pl ([193.178.161.156]:55409 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752710Ab2KTNA7 (ORCPT ); Tue, 20 Nov 2012 08:00:59 -0500 From: "Rafael J. Wysocki" To: Mika Westerberg Cc: grant.likely@secretlab.ca, linus.walleij@linaro.org, w.sang@pengutronix.de, rafael.j.wysocki@intel.com, linux-kernel@vger.kernel.org, lenb@kernel.org, broonie@opensource.wolfsonmicro.com, khali@linux-fr.org, ben-linux@fluff.org, bhelgaas@google.com, mathias.nyman@linux.intel.com, linux-acpi@vger.kernel.org Subject: Re: [PATCH v3 2/3] spi / ACPI: add ACPI enumeration support Date: Tue, 20 Nov 2012 14:05:26 +0100 Message-ID: <12657869.yQS4p6Y8j3@vostro.rjw.lan> User-Agent: KMail/4.9.3 (Linux/3.7.0-rc6; KDE/4.9.3; x86_64; ; ) In-Reply-To: <1353407384-26880-3-git-send-email-mika.westerberg@linux.intel.com> References: <1352977397-2280-1-git-send-email-mika.westerberg@linux.intel.com> <1353407384-26880-1-git-send-email-mika.westerberg@linux.intel.com> <1353407384-26880-3-git-send-email-mika.westerberg@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6040 Lines: 201 On Tuesday, November 20, 2012 12:29:43 PM Mika Westerberg wrote: > 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 > --- > drivers/spi/spi.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 114 insertions(+), 1 deletion(-) > > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > index 84c2861..3ae5351 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 +894,112 @@ 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 acpi_resource_spi_serialbus *sb; > + struct spi_device *spi = data; > + struct resource r; > + > + switch (ares->type) { > + case ACPI_RESOURCE_TYPE_IRQ: > + case ACPI_RESOURCE_TYPE_EXTENDED_IRQ: It is not necessary to check the resource type for IRQ resources here, because acpi_dev_resource_interrupt() will do it for you anyway. :-) So, I would first check if the resource type is ACPI_RESOURCE_TYPE_SERIAL_BUS (and populate the spi_device fields if so) and then do something like this: if (acpi_dev_resource_interrupt(ares, 0, &r)) { if (spi->irq < 0) spi->irq = r.start; return 1; } We don't even need to memset(), because we're not going to use that resource object going forward. > + /* Only use the first interrupt resource and skip the rest */ > + memset(&r, 0, sizeof(r)); > + if (spi->irq < 0 && acpi_dev_resource_interrupt(ares, 0, &r)) > + spi->irq = r.start; > + return 1; > + > + case ACPI_RESOURCE_TYPE_SERIAL_BUS: > + 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; > + > + return 1; > + } > + return 0; > + } > + > + return 0; We're not interested in any resources except for the above, so I think we can just always return 1 from this function, or am I missing anything? > +} > + > +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); can be done here (the list is going to be empty anyway if acpi_spi_add_resource() always returns 1) and then you won't need the fail_put_dev label. > + if (ret < 0) > + goto fail_put_dev; > + > + acpi_dev_free_resource_list(&resource_list); > + > + if (!spi->max_speed_hz) > + goto fail_put_dev; > + > + 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)); > + goto fail_put_dev; > + } > + > + return AE_OK; > + > +fail_put_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 +1135,9 @@ 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; > } Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/