Re: [PATCH 2/2] mfd: anatop: permit adata be NULL when accessregister

From: Shawn Guo
Date: Sun May 13 2012 - 23:32:17 EST


On Sun, May 13, 2012 at 08:59:54AM +0800, Richard Zhao wrote:
> It makes anatop register access easier. Anatop has many misc registers,
> which may not be a specific driver.
>
> There's only one anatop device for a running system, so we use a global
> variable to store struct anatop.
>
>From what I see, it's reasonable. Then the immediate question I have
is, should we remove "struct anatop *adata" from anatop_read_reg and
anatop_write_reg completely?

Regards,
Shawn

> Signed-off-by: Richard Zhao <richard.zhao@xxxxxxxxxxxxx>
> ---
> drivers/mfd/anatop-mfd.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/mfd/anatop-mfd.c b/drivers/mfd/anatop-mfd.c
> index 3bb7c49..b0313210 100644
> --- a/drivers/mfd/anatop-mfd.c
> +++ b/drivers/mfd/anatop-mfd.c
> @@ -41,8 +41,15 @@
> #include <linux/of_address.h>
> #include <linux/mfd/anatop.h>
>
> +/* For any running system, there's only one anatop device. */
> +static struct anatop *anatop_data;
> +
> u32 anatop_read_reg(struct anatop *adata, u32 addr)
> {
> + BUG_ON(!anatop_data);
> + if (!adata)
> + adata = anatop_data;
> +
> return readl(adata->ioreg + addr);
> }
> EXPORT_SYMBOL_GPL(anatop_read_reg);
> @@ -51,6 +58,10 @@ void anatop_write_reg(struct anatop *adata, u32 addr, u32 data, u32 mask)
> {
> u32 val;
>
> + BUG_ON(!anatop_data);
> + if (!adata)
> + adata = anatop_data;
> +
> data &= mask;
>
> spin_lock(&adata->reglock);
> @@ -83,6 +94,7 @@ static int __devinit of_anatop_probe(struct platform_device *pdev)
> drvdata->ioreg = ioreg;
> spin_lock_init(&drvdata->reglock);
> platform_set_drvdata(pdev, drvdata);
> + anatop_data = drvdata;
> of_platform_populate(np, of_anatop_match, NULL, dev);
>
> return 0;
> --
> 1.7.9.5
>
>
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>

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