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Message-ID: <20110513012520.GL18952@game.jcrosoft.org>
Date: Fri, 13 May 2011 03:25:20 +0200
From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@...osoft.com>
To: Ryan Mallon <ryan@...ewatersys.com>
Cc: Josh Wu <josh.wu@...el.com>, mchehab@...hat.com,
linux-kernel@...r.kernel.org, lars.haring@...el.com,
g.liakhovetski@....de, linux-arm-kernel@...ts.infradead.org,
linux-media@...r.kernel.org
Subject: Re: [PATCH] [media] at91: add Atmel Image Sensor Interface (ISI)
support
> > +
> > +/* Constants for RGB_CFG(ISI_V2) */
> > +#define ISI_V2_RGB_CFG_DEFAULT 0
> > +#define ISI_V2_RGB_CFG_MODE_1 1
> > +#define ISI_V2_RGB_CFG_MODE_2 2
> > +#define ISI_V2_RGB_CFG_MODE_3 3
> > +
> > +/* Bit manipulation macros */
> > +#define ISI_BIT(name) \
> > + (1 << ISI_##name##_OFFSET)
> > +#define ISI_BF(name, value) \
> > + (((value) & ((1 << ISI_##name##_SIZE) - 1)) \
> > + << ISI_##name##_OFFSET)
> > +#define ISI_BFEXT(name, value) \
> > + (((value) >> ISI_##name##_OFFSET) \
> > + & ((1 << ISI_##name##_SIZE) - 1))
> > +#define ISI_BFINS(name, value, old) \
> > + (((old) & ~(((1 << ISI_##name##_SIZE) - 1) \
> > + << ISI_##name##_OFFSET))\
> > + | ISI_BF(name, value))
>
> I really dislike this kind of register access magic. Not sure how others
> feel about it. These macros are really ugly.
>
> > +/* Register access macros */
> > +#define isi_readl(port, reg) \
> > + __raw_readl((port)->regs + ISI_##reg)
> > +#define isi_writel(port, reg, value) \
> > + __raw_writel((value), (port)->regs + ISI_##reg)
>
> If the token pasting stuff gets dropped then these can be static inline
> functions which is preferred.
Sorry this make the C code much readable
and this can not be done as a inline
so please keep it as is
>
> > +
> > +#define ATMEL_V4L2_VID_FLAGS (V4L2_CAP_VIDEO_OUTPUT)
> > +
> > +struct atmel_isi;
> > +
> > +enum atmel_isi_pixfmt {
> > + ATMEL_ISI_PIXFMT_GREY, /* Greyscale */
> > + dev_info(&pdev->dev,
> > + "No config available using default values\n");
> > + pdata = &isi_default_data;
> > + }
> > +
> > + isi->pdata = pdata;
> > + isi->platform_flags = pdata->flags;
> > + if (isi->platform_flags == 0)
> > + isi->platform_flags = ISI_DATAWIDTH_8;
>
> We could be mean here an require that people get the flags correct, e.g.
>
> if (!((isi->platform_flags & ISI_DATA_WIDTH_8) ||
> (isi->platform_flags & ISI_DATA_WIDTH_8))) {
> dev_err(&pdev->dev, "No data width specified\n");
> err = -ENOMEM;
> goto fail;
> }
>
> Which discourages sloppy coding in the board files.
if this means default configuration so not need to have all board to set it
>
> > +
> > + isi_writel(isi, V2_CTRL, ISI_BIT(V2_DIS));
> > + /* Check if module disable */
> > + while (isi_readl(isi, V2_STATUS) & ISI_BIT(V2_DIS))
> > + cpu_relax();
> > +
> > + irq = platform_get_irq(pdev, 0);
Best Regards,
J.
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