Hi,
Am Montag, 2. März 2020, 16:57:02 CET schrieb Mylène Josserand:
> Determine which revision of rk3288 by checking the HDMI version.
> According to the Rockchip BSP kernel, on rk3288w, the HDMI
> revision equals 0x1A which is not the case for the rk3288 [1].
>
> As these SOC have some differences, the new function
> 'soc_is_rk3288w' will help us to know on which revision
> we are.
what happened to just having a different compatible in the dts?
Aka doing a
rk3288w.dtsi with
#include "rk3288.dtsi"
&cru {
compatible = "rockchip,rk3288w-cru";
}
I somehow don't expect boards to just switch between soc variants
on the fly.
Also, doing things in mach-rockchip is not very future-proof:
(1) having random soc-specific APIs spanning the kernel feels wrong,
especially as at some point it might not be contained to our own special
drivers like the cru. I cannot really see people being enthusiastic if
something like this would be needed in say the core Analogix-DP bridge ;-)
(2) I guess the rk3288w will not be the last soc doing this and on arm64 you
can't do it that way, as there is no mach-rockchip there
So my personal preference would really would be just a specific compatible
for affected ip blocks.
Heiko
> [1]:https://github.com/rockchip-linux/u-boot/blob/f992fe3334aa5090acb448261982628b5a3d37a5/arch/arm/include/asm/arch-rockchip/cpu.h#L30..L34
>
> Signed-off-by: Mylène Josserand <mylene.josserand@xxxxxxxxxxxxx>
> ---
> arch/arm/mach-rockchip/rockchip.c | 45 +++++++++++++++++++++++++++++++
> include/soc/rockchip/revision.h | 22 +++++++++++++++
> 2 files changed, 67 insertions(+)
> create mode 100644 include/soc/rockchip/revision.h
>
> diff --git a/arch/arm/mach-rockchip/rockchip.c b/arch/arm/mach-rockchip/rockchip.c
> index f9797a2b5d0d..b907ba390093 100644
> --- a/arch/arm/mach-rockchip/rockchip.c
> +++ b/arch/arm/mach-rockchip/rockchip.c
> @@ -9,12 +9,14 @@
> #include <linux/kernel.h>
> #include <linux/init.h>
> #include <linux/io.h>
> +#include <linux/of_address.h>
> #include <linux/of_platform.h>
> #include <linux/irqchip.h>
> #include <linux/clk-provider.h>
> #include <linux/clocksource.h>
> #include <linux/mfd/syscon.h>
> #include <linux/regmap.h>
> +#include <soc/rockchip/revision.h>
> #include <asm/mach/arch.h>
> #include <asm/mach/map.h>
> #include <asm/hardware/cache-l2x0.h>
> @@ -22,6 +24,49 @@
> #include "pm.h"
>
> #define RK3288_TIMER6_7_PHYS 0xff810000
> +#define RK3288_HDMI_REV_REG 0x04
> +#define RK3288W_HDMI_REV 0x1A
> +
> +static const struct of_device_id rk3288_dt_hdmi_match[] __initconst = {
> + { .compatible = "rockchip,rk3288-dw-hdmi" },
> + { }
> +};
> +
> +int rk3288_get_revision(void)
> +{
> + static int revision = RK3288_SOC_REV_UNKNOWN;
> + struct device_node *dn;
> + void __iomem *hdmi_base;
> +
> + if (revision != RK3288_SOC_REV_UNKNOWN)
> + return revision;
> +
> + dn = of_find_matching_node(NULL, rk3288_dt_hdmi_match);
> + if (!dn) {
> + pr_err("%s: Couldn't find HDMI node\n", __func__);
> + return -EINVAL;
> + }
> +
> + hdmi_base = of_iomap(dn, 0);
> + of_node_put(dn);
> +
> + if (!hdmi_base) {
> + pr_err("%s: Couldn't map %pOF regs\n", __func__,
> + hdmi_base);
> + return -ENXIO;
> + }
> +
> + if (readl_relaxed(hdmi_base + RK3288_HDMI_REV_REG) ==
> + RK3288W_HDMI_REV)
> + revision = RK3288_SOC_REV_RK3288W;
> + else
> + revision = RK3288_SOC_REV_RK3288;
> +
> + iounmap(hdmi_base);
> +
> + return revision;
> +}
> +EXPORT_SYMBOL(rk3288_get_revision);
>
> static void __init rockchip_timer_init(void)
> {
> diff --git a/include/soc/rockchip/revision.h b/include/soc/rockchip/revision.h
> new file mode 100644
> index 000000000000..226419c60af0
> --- /dev/null
> +++ b/include/soc/rockchip/revision.h
> @@ -0,0 +1,22 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright 2020 Collabora
> + */
> +
> +#ifndef __SOC_ROCKCHIP_REVISION_H__
> +#define __SOC_ROCKCHIP_REVISION_H__
> +
> +enum rk3288_soc_revision {
> + RK3288_SOC_REV_UNKNOWN,
> + RK3288_SOC_REV_RK3288,
> + RK3288_SOC_REV_RK3288W,
> +};
> +
> +int rk3288_get_revision(void);
> +
> +static inline bool soc_is_rk3288w(void)
> +{
> + return rk3288_get_revision() == RK3288_SOC_REV_RK3288W;
> +}
> +
> +#endif /* __SOC_ROCKCHIP_REVISION_H__ */
>
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