On Tuesday, October 4, 2016 11:09:27 AM CEST Geert Uytterhoeven wrote:
> Identify the SoC type and revision, and register this information with
> the SoC bus, so it is available under /sys/devices/soc0/, and can be
> checked where needed using soc_device_match().
>
> In addition, on SoCs that support it, the product ID is read from a
> hardware register and validated, to catch accidental use of a DTB for a
> different SoC.
>
> Example:
>
> Detected Renesas r8a7791 ES1.0
> ...
> # cat /sys/devices/soc0/{family,machine,soc_id,revision}
> R-Car Gen2
> Koelsch
> r8a7791
> ES1.0
>
Seems all reasonable.
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> This patch does NOT add a call to
>
> of_platform_default_populate(NULL, NULL,
> soc_device_to_device(soc_dev));
>
> Contrary to suggested by commit 74d1d82cdaaec727 ("drivers/base: add bus
> for System-on-Chip devices), doing so would not only move on-SoC devices
> from /sys/devices/platform/ to /sys/devices/soc0/, but also all other
> board (off-SoC) devices specified in the DTB.
Right, we have moved away from that a while ago, and now just
use the device for identification, not to model the device
hierarchy.
> diff --git a/drivers/soc/renesas/renesas-soc.c b/drivers/soc/renesas/renesas-soc.c
> new file mode 100644
> index 0000000000000000..74b72e4112b8889e
> --- /dev/null
> +++ b/drivers/soc/renesas/renesas-soc.c
> @@ -0,0 +1,266 @@
> +/*
> + * Renesas SoC Identification
> + *
> + * Copyright (C) 2014-2016 Glider bvba
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/sys_soc.h>
> +
> +
> +struct renesas_family {
> + const char name[16];
> + u32 reg; /* CCCR, PVR, or PRR */
> +};
> +
> +static const struct renesas_family fam_emev2 __initconst = {
> + .name = "Emma Mobile EV2",
> +};
As this is not related to the others and doesn't have the respective
register, I'd leave the platform out of this, and possibly have
a separate driver for it.
> +static const struct renesas_family fam_rza __initconst = {
> + .name = "RZ/A",
> +};
I'm not sure about the relationship between this one and the others,
maybe it should be treated in the same way as emev2 and left out from
this driver?
> +static const struct renesas_family fam_rmobile __initconst = {
> + .name = "R-Mobile",
> + .reg = 0xe600101c, /* CCCR (Common Chip Code Register) */
> +};
> +
> +static const struct renesas_family fam_rcar_gen1 __initconst = {
> + .name = "R-Car Gen1",
> + .reg = 0xff000044, /* PRR (Product Register) */
> +};
> +
> +static const struct renesas_family fam_rcar_gen2 __initconst = {
> + .name = "R-Car Gen2",
> + .reg = 0xff000044, /* PRR (Product Register) */
> +};
> +
> +static const struct renesas_family fam_rcar_gen3 __initconst = {
> + .name = "R-Car Gen3",
> + .reg = 0xfff00044, /* PRR (Product Register) */
> +};
> +
> +static const struct renesas_family fam_rzg __initconst = {
> + .name = "RZ/G",
> + .reg = 0xff000044, /* PRR (Product Register) */
> +};
> +
> +static const struct renesas_family fam_shmobile __initconst = {
> + .name = "SH-Mobile",
> + .reg = 0xe600101c, /* CCCR (Common Chip Code Register) */
> +};
These seem to fall into two distinct categories, maybe there is a
better way to group them. What device contain the two kinds of
registers (PRR, CCCR)?
Hardcoding the register address seems rather ugly here, so maybe
there is a way to have two separate probe methods based on the
surrounding register range, and then bind to that?
> +static const struct of_device_id renesas_socs[] __initconst = {
> +#ifdef CONFIG_ARCH_EMEV2
> + { .compatible = "renesas,emev2", .data = &soc_emev2 },
> +#endif
> +#ifdef CONFIG_ARCH_R7S72100
> + { .compatible = "renesas,r7s72100", .data = &soc_rz_a1h },
> +#endif
> +#ifdef CONFIG_ARCH_R8A73A4
I think the #ifdefs here will result in warnings for unused symbols
when the Kconfig symbols are disabled.
Arnd
