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    SubjectRe: [PATCH v2 6/9] misc: Generic on-chip SRAM allocation driver
    On Fri, Aug 31, 2012 at 11:27:01AM +0200, Philipp Zabel wrote:
    > This driver requests and remaps a memory region as configured in the
    > device tree. It serves memory from this region via the genalloc API.
    >
    > Other drivers can retrieve the genalloc pool from a phandle pointing
    > to this drivers' device node in the device tree.
    >
    > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
    > ---
    > drivers/misc/Kconfig | 8 ++++
    > drivers/misc/Makefile | 1 +
    > drivers/misc/sram.c | 105 +++++++++++++++++++++++++++++++++++++++++++++++++
    > 3 files changed, 114 insertions(+)
    > create mode 100644 drivers/misc/sram.c
    >
    > diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
    > index 98a442d..8a55284 100644
    > --- a/drivers/misc/Kconfig
    > +++ b/drivers/misc/Kconfig
    > @@ -509,6 +509,14 @@ config USB_SWITCH_FSA9480
    > stereo and mono audio, video, microphone and UART data to use
    > a common connector port.
    >
    > +config SRAM
    > + bool "Generic on-chip SRAM driver\n"

    Remove the "\n".

    And "depends on HAS_IOMEM"?

    > + select GENERIC_ALLOCATOR
    > + help
    > + This driver allows to declare a memory region to be managed
    > + by the genalloc API. It is supposed to be used for small
    > + on-chip SRAM areas found on many ARM SoCs.
    > +
    > source "drivers/misc/c2port/Kconfig"
    > source "drivers/misc/eeprom/Kconfig"
    > source "drivers/misc/cb710/Kconfig"
    > diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
    > index b88df7a..ccc759a 100644
    > --- a/drivers/misc/Makefile
    > +++ b/drivers/misc/Makefile
    > @@ -50,3 +50,4 @@ obj-y += carma/
    > obj-$(CONFIG_USB_SWITCH_FSA9480) += fsa9480.o
    > obj-$(CONFIG_ALTERA_STAPL) +=altera-stapl/
    > obj-$(CONFIG_INTEL_MEI) += mei/
    > +obj-$(CONFIG_SRAM) += sram.o
    > diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
    > new file mode 100644
    > index 0000000..c5cf67e
    > --- /dev/null
    > +++ b/drivers/misc/sram.c
    > @@ -0,0 +1,105 @@
    > +/*
    > + * Generic on-chip SRAM allocation driver
    > + *
    > + * Copyright (C) 2012 Philipp Zabel, Pengutronix
    > + *
    > + * This program is free software; you can redistribute it and/or
    > + * modify it under the terms of the GNU General Public License
    > + * as published by the Free Software Foundation; either version 2
    > + * of the License, or (at your option) any later version.
    > + * This program is distributed in the hope that it will be useful,
    > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
    > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    > + * GNU General Public License for more details.
    > + *
    > + * You should have received a copy of the GNU General Public License
    > + * along with this program; if not, write to the Free Software
    > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
    > + * MA 02110-1301, USA.
    > + */
    > +
    > +#include <linux/kernel.h>
    > +#include <linux/module.h>
    > +#include <linux/io.h>
    > +#include <linux/of.h>
    > +#include <linux/platform_device.h>
    > +#include <linux/spinlock.h>
    > +#include <linux/genalloc.h>
    > +
    > +struct sram_dev {
    > + struct gen_pool *pool;
    > +};
    > +
    > +static int __devinit sram_probe(struct platform_device *pdev)
    > +{
    > + void __iomem *virt_base;
    > + struct sram_dev *sram;
    > + struct resource *res;
    > + unsigned long size;
    > + int ret;
    > +
    > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    > + if (!res)
    > + return -EINVAL;
    > +
    > + size = resource_size(res);
    > +
    > + virt_base = devm_request_and_ioremap(&pdev->dev, res);
    > + if (!virt_base)
    > + return -ENOMEM;

    The kerneldoc of devm_request_and_ioremap suggests -EADDRNOTAVAIL.

    Regards,
    Shawn

    > +
    > + sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
    > + if (!sram)
    > + return -ENOMEM;
    > +
    > + sram->pool = gen_pool_create(PAGE_SHIFT, -1);
    > + if (!sram->pool)
    > + return -ENOMEM;
    > +
    > + ret = gen_pool_add_virt(sram->pool, (unsigned long)virt_base,
    > + res->start, size, -1);
    > + if (ret < 0) {
    > + gen_pool_destroy(sram->pool);
    > + return ret;
    > + }
    > +
    > + platform_set_drvdata(pdev, sram);
    > +
    > + dev_dbg(&pdev->dev, "SRAM pool: %ld KiB @ 0x%p\n", size / 1024, virt_base);
    > +
    > + return 0;
    > +}
    > +
    > +static int __devexit sram_remove(struct platform_device *pdev)
    > +{
    > + struct sram_dev *sram = platform_get_drvdata(pdev);
    > +
    > + if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
    > + dev_dbg(&pdev->dev, "removed while SRAM allocated\n");
    > +
    > + gen_pool_destroy(sram->pool);
    > +
    > + return 0;
    > +}
    > +
    > +#ifdef CONFIG_OF
    > +static struct of_device_id sram_dt_ids[] = {
    > + { .compatible = "sram" },
    > + { /* sentinel */ }
    > +};
    > +#endif
    > +
    > +static struct platform_driver sram_driver = {
    > + .driver = {
    > + .name = "sram",
    > + .of_match_table = of_match_ptr(sram_dt_ids),
    > + },
    > + .probe = sram_probe,
    > + .remove = __devexit_p(sram_remove),
    > +};
    > +
    > +module_platform_driver(sram_driver);
    > +
    > +MODULE_LICENSE("GPL");
    > +MODULE_AUTHOR("Philipp Zabel, Pengutronix");
    > +MODULE_DESCRIPTION("Generic SRAM allocator driver");
    > --
    > 1.7.10.4
    >


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