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SubjectRe: [PATCHv1 2/6] dmaengine: dw_dmac: add driver for Atmel AT32
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On Tue, Sep 25, 2012 at 5:43 PM, Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
>
> This driver should be usable on all platforms that depend on clk API.

This is not what you mentioned in subject :(

> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> drivers/dma/Kconfig | 9 +++
> drivers/dma/Makefile | 1 +
> drivers/dma/dw_dmac.c | 23 +------
> drivers/dma/dw_dmac_at32.c | 150 ++++++++++++++++++++++++++++++++++++++++++++

I don't agree with the naming used here. There is nothing AT32
specific here. It is actively used
by SPEAr. It should be named dw_dmac_platform.c or *pltfm.c

> 4 files changed, 162 insertions(+), 21 deletions(-)
> create mode 100644 drivers/dma/dw_dmac_at32.c
>
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index df32537..e47cc90 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -89,6 +89,15 @@ config DW_DMAC
> Support the Synopsys DesignWare AHB DMA controller. This
> can be integrated in chips such as the Atmel AT32ap7000.
>
> +config DW_DMAC_AT32
> + tristate "Synopsys DesignWare AHB DMA support for Atmel"

:(

> + depends on HAVE_CLK

Even this is not a must for all users of platform driver. So can leave this.

> + select DW_DMAC
> + default y if CPU_AT32AP7000
> + help
> + Support the Synopsys DesignWare AHB DMA controller in the chips
> + such as the Atmel AT32ap7000.
> +
> config AT_HDMAC
> tristate "Atmel AHB DMA support"
> depends on ARCH_AT91

> diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
> index d9344a7..9c8a500 100644
> --- a/drivers/dma/dw_dmac.c
> +++ b/drivers/dma/dw_dmac.c
> @@ -18,7 +18,6 @@
> #include <linux/init.h>
> #include <linux/interrupt.h>
> #include <linux/io.h>
> -#include <linux/of.h>
> #include <linux/mm.h>
> #include <linux/module.h>
> #include <linux/platform_device.h>
> @@ -1681,35 +1680,17 @@ static const struct dev_pm_ops dw_dev_pm_ops = {
> .poweroff_noirq = dw_suspend_noirq,
> };
>
> -#ifdef CONFIG_OF
> -static const struct of_device_id dw_dma_id_table[] = {
> - { .compatible = "snps,dma-spear1340" },
> - {}
> -};
> -MODULE_DEVICE_TABLE(of, dw_dma_id_table);
> -#endif
> -
> static struct platform_driver dw_driver = {
> + .probe = dw_probe,
> .remove = __devexit_p(dw_remove),
> .shutdown = dw_shutdown,
> .driver = {
> .name = "dw_dmac",
> .pm = &dw_dev_pm_ops,
> - .of_match_table = of_match_ptr(dw_dma_id_table),
> },
> };
>
> -static int __init dw_init(void)
> -{
> - return platform_driver_probe(&dw_driver, dw_probe);
> -}
> -subsys_initcall(dw_init);
> -
> -static void __exit dw_exit(void)
> -{
> - platform_driver_unregister(&dw_driver);
> -}
> -module_exit(dw_exit);
> +module_platform_driver(dw_driver);

Shouldn't this be a separate patch?

>
> MODULE_LICENSE("GPL v2");
> MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller driver");
> diff --git a/drivers/dma/dw_dmac_at32.c b/drivers/dma/dw_dmac_at32.c
> new file mode 100644
> index 0000000..7bc7ac4
> --- /dev/null
> +++ b/drivers/dma/dw_dmac_at32.c
> @@ -0,0 +1,150 @@
> +/*
> + * Driver for the Synopsys DesignWare DMA Controller

How is this file different from dw_dmac.c?

> + *
> + * The driver is based on the excerpts from the original dw_dmac.c. That's why
> + * the same copyright holders are mentioned here as well.
> + *
> + * Copyright (C) 2007-2008 Atmel Corporation
> + * Copyright (C) 2010-2011 ST Microelectronics
> + * Copyright (C) 2012 Intel Corporation
> + *
> + * 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 <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/clk.h>
> +#include <linux/of.h>
> +#include <linux/dw_dmac.h>
> +
> +struct dw_at32 {
> + struct platform_device *pdev;
> + struct clk *clk;
> +};
> +
> +static int __init dw_at32_probe(struct platform_device *pdev)
> +{
> + struct dw_at32 *at32;
> + struct platform_device *pd;
> + struct dw_dma_platform_data *pdata = pdev->dev.platform_data;
> + static int instance;
> + int ret;
> +
> + at32 = devm_kzalloc(&pdev->dev, sizeof(*at32), GFP_KERNEL);
> + if (!at32) {
> + dev_err(&pdev->dev, "can't allocate memory\n");
> + return -ENOMEM;
> + }
> +
> + pd = platform_device_alloc("dw_dmac", instance);
> + if (!pd) {
> + dev_err(&pdev->dev, "can't allocate dw_dmac platform device\n");
> + return -ENOMEM;
> + }

Why create another device? Why not simply call dw_probe() from here?


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