Hi Afzal,
On 05/01/2012 07:20 AM, Afzal Mohammed wrote:
> Some boards depend on bootloader to update chip select value for NAND.
> It is felt that Kernel should not depend on bootloader to get CS, as
> for a particular board CS is hardwired and is fixed, hence this can
> directly be updated in Kernel. But as CS value for boards that depend
> on this behaviour is not available, educate gpmc driver to acquire
> chip select value for NAND. this ideally should be removed once CS
> for those boards are available.
Do you know how many boards require this? If so which are those boards?
> Signed-off-by: Afzal Mohammed <afzal@xxxxxx>
> ---
> arch/arm/mach-omap2/gpmc.c | 32 +++++++++++++++++++++++++++++++-
> 1 file changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
> index 657ce95..ecd3384 100644
> --- a/arch/arm/mach-omap2/gpmc.c
> +++ b/arch/arm/mach-omap2/gpmc.c
> @@ -892,6 +892,30 @@ static int __init gpmc_init(void)
> }
> postcore_initcall(gpmc_init);
>
> +static __devinit int gpmc_acquire_nand_cs(struct gpmc *gpmc,
> + struct gpmc_device_pdata *gdp)
> +{
> + int cs = 0;
> + struct omap_nand_platform_data *nand = gdp->pdata;
> +
> + if ((nand->cs >= 0) && (nand->cs < GPMC_CS_NUM))
> + return 0;
> +
> + while (cs < GPMC_CS_NUM) {
> + u32 l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
> +
> + if ((l & GPMC_CONFIG1_DEVICETYPE(~0)) ==
> + GPMC_CONFIG1_DEVICETYPE_NAND) {
> + dev_info(gpmc->dev, "found NAND on CS: %d\n", cs);
> + nand->cs = cs;
> + gdp->cs_data->cs = cs;
> + return 0;
> + }
> + cs++;
> + }
> + return -ENODEV;
> +}
> +
> static __devinit void gpmc_update_nand_reg(struct gpmc *gpmc,
> struct omap_nand_platform_data *nand)
> {
> @@ -1450,8 +1474,14 @@ static __devinit int gpmc_probe(struct platform_device *pdev)
>
> for (i = 0, gdq = gp->device_pdata, gd = gpmc->device;
> (i < gp->num_device) && (*gdq); i++, gdq++) {
> - if ((*gdq)->is_nand)
> + if ((*gdq)->is_nand) {
> + ret = gpmc_acquire_nand_cs(gpmc, *gdq);
> + if (IS_ERR_VALUE(ret)) {
> + dev_err(gpmc->dev, "CS error: %d\n", ret);
> + continue;
> + }
Should this code be marked with a FIXME?
Cheers
Jon
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
