Re: [PATCH 3/4] arm: am33xx: DT quirks for am33xx based beaglebone variants

From: Tony Lindgren
Date: Thu Feb 19 2015 - 13:41:48 EST


* Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx> [150218 07:03]:
> Implement DT quirks for the am33xx beaglebone boards.
> --- /dev/null
> +++ b/arch/arm/mach-omap2/am33xx-dt-quirks.c
...
> +
> +/*
> + * The board IDs for am33xx board are in an I2C EEPROM
> + * We are very early in the boot process so we have to
> + * read the EEPROM directly without using the I2C layer.
> + *
> + * Note that we rely on the bootloader setting up the muxes
> + * (which is the case for u-boot).
> + */
> +
> +/* I2C Status Register (OMAP_I2C_STAT): */
> +#define OMAP_I2C_STAT_XDR (1 << 14) /* TX Buffer draining */
> +#define OMAP_I2C_STAT_RDR (1 << 13) /* RX Buffer draining */
> +#define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */
> +#define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */
> +#define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */
> +#define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */
> +#define OMAP_I2C_STAT_BF (1 << 8) /* Bus Free */
> +#define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */
> +#define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */
> +#define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */
> +#define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */
> +#define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */
...

Uhh I don't like the idea of duplicating the i2c-omap.c driver under
arch/arm.. And in general we should initialize things later rather
than earlier.

What's stopping doing these quirk checks later on time with just
a regular device driver, something like drivers/misc/bbone-quirks.c?

Regards,

Tony
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