[U-Boot] [PATCH v3 2/2] arm: add initial support for Amlogic Meson and ODROID-C2

[Beniamino Galvani <b.galvani@gmail.com>]

On Mon, Apr 11, 2016 at 02:08:56AM +0200, Marek Vasut wrote:
>
> > +#define GXBB_GPIO_0_EN		GXBB_PERIPHS_ADDR(0x0c)
> > +#define GXBB_GPIO_0_OUT		GXBB_PERIPHS_ADDR(0x0d)
> > +#define GXBB_GPIO_0_IN		GXBB_PERIPHS_ADDR(0x0e)
> 
> You can also define this as
> GXBB_GPIO_EN(n)  (0xc + 3 * (n) + 0)
> GXBB_GPIO_OUT(n) (0xc + 3 * (n) + 1)
> GXBB_GPIO_IN(n)  (0xc + 3 * (n) + 2)

This would work well if GPIO_6 didn't exist :)

> > +#define GXBB_GPIO_1_EN		GXBB_PERIPHS_ADDR(0x0f)
> > +#define GXBB_GPIO_1_OUT		GXBB_PERIPHS_ADDR(0x10)
> > +#define GXBB_GPIO_1_IN		GXBB_PERIPHS_ADDR(0x11)
> > +#define GXBB_GPIO_2_EN		GXBB_PERIPHS_ADDR(0x12)
> > +#define GXBB_GPIO_2_OUT		GXBB_PERIPHS_ADDR(0x13)
> > +#define GXBB_GPIO_2_IN		GXBB_PERIPHS_ADDR(0x14)
> > +#define GXBB_GPIO_3_EN		GXBB_PERIPHS_ADDR(0x15)
> > +#define GXBB_GPIO_3_OUT		GXBB_PERIPHS_ADDR(0x16)
> > +#define GXBB_GPIO_3_IN		GXBB_PERIPHS_ADDR(0x17)
> > +#define GXBB_GPIO_4_EN		GXBB_PERIPHS_ADDR(0x18)
> > +#define GXBB_GPIO_4_OUT		GXBB_PERIPHS_ADDR(0x19)
> > +#define GXBB_GPIO_4_IN		GXBB_PERIPHS_ADDR(0x1a)
> > +#define GXBB_GPIO_5_EN		GXBB_PERIPHS_ADDR(0x1b)
> > +#define GXBB_GPIO_5_OUT		GXBB_PERIPHS_ADDR(0x1c)
> > +#define GXBB_GPIO_5_IN		GXBB_PERIPHS_ADDR(0x1d)
> > +#define GXBB_GPIO_6_EN		GXBB_PERIPHS_ADDR(0x08)
> > +#define GXBB_GPIO_6_OUT		GXBB_PERIPHS_ADDR(0x09)
> > +#define GXBB_GPIO_6_IN		GXBB_PERIPHS_ADDR(0x0a)

> It'd be nice to have base addresses somewhere at the beginning instead
> of having them mixed with the bit macros, but that's a matter of taste.

I agree, I'll change this.

> > +	val = fdt_getprop(gd->fdt_blob, offset, "reg", &len);
> > +	if (len < sizeof(*val) * 4)
> > +		return -EINVAL;
> > +
> > +	/* Don't use fdt64_t to avoid unaligned access */
> 
> This looks iffy, can you elaborate on this issue ?

I was getting a "Synchronous Abort handler, esr 0x96000021" which
seemed to indicate a alignment fault, but thinking again about it I'm
not sure anymore of the real cause. fdt64_t and fdt64_to_cpu() don't
work here, I will try to investigate better why. Suggestions are
welcome :)

> > +	/* Reserve first 16 MiB of RAM */
> 
> Why ?

I'll add a comment, first 16 MiB seems to be reserved for firmware.

> > +void reset_cpu(ulong addr)
> > +{
> 
> How does the system reboot then ?

The system reboots through a call to secure monitor, which is not
implemented in this submission.

> > +struct mm_region *mem_map = gxbb_mem_map;
> 
> This looks super-iffy, I wouldn't be surprised if this started being
> optimized away at some point.

I don't understand, why that should happen?

> > +	/* Reset PHY on GPIOZ_14 */
> > +	clrbits_le32(GXBB_GPIO_3_EN, BIT(14));
> > +	clrbits_le32(GXBB_GPIO_3_OUT, BIT(14));
> > +	udelay(100000);
> 
> mdelay(100); , though that is quite some wait.

Will change and decrease the timeout.

> > diff --git a/drivers/serial/serial_meson.c b/drivers/serial/serial_meson.c
> 
> This should go in a separate patch.

I originally submitted the driver as separate patch, then Tom
suggested that the initial platform patch should contain everything
needed to perform a boot, so UART, DDR, board file and DTS.

Thanks for the review,

Beniamino