Re: [PATCH v2 04/12] soc: renesas: sysc: Add SoC identification for RZ/V2N SoC

[Lad, Prabhakar]

Hi Geert,

Thank you for the review.

On Thu, Apr 10, 2025 at 10:28 AM Geert Uytterhoeven
<geert@xxxxxxxxxxxxxx> wrote:
>
> Hi Prabhakar,
>
> On Mon, 7 Apr 2025 at 21:16, Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> >
> > Add SoC identification for the RZ/V2N SoC using the System Controller
> > (SYS) block.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>
> Thanks for your patch!
>
> > --- /dev/null
> > +++ b/drivers/soc/renesas/r9a09g056-sys.c
> > @@ -0,0 +1,107 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * RZ/V2N System controller (SYS) driver
> > + *
> > + * Copyright (C) 2025 Renesas Electronics Corp.
> > + */
> > +
> > +#include <linux/bitfield.h>
> > +#include <linux/bits.h>
> > +#include <linux/device.h>
> > +#include <linux/init.h>
> > +#include <linux/io.h>
> > +#include <linux/string.h>
> > +
> > +#include "rz-sysc.h"
> > +
> > +/* Register Offsets */
> > +#define SYS_LSI_MODE           0x300
> > +#define SYS_LSI_MODE_SEC_EN    BIT(16)
> > +/*
> > + * BOOTPLLCA[1:0]
> > + *         [0,0] => 1.1GHZ
> > + *         [0,1] => 1.5GHZ
> > + *         [1,0] => 1.6GHZ
> > + *         [1,1] => 1.7GHZ
> > + */
> > +#define SYS_LSI_MODE_STAT_BOOTPLLCA55  GENMASK(12, 11)
> > +#define SYS_LSI_MODE_CA55_1_7GHZ       0x3
> > +
> > +#define SYS_LSI_PRR                    0x308
> > +#define SYS_LSI_PRR_GPU_DIS            BIT(0)
> > +#define SYS_LSI_PRR_ISP_DIS            BIT(4)
> > +
> > +#define SYS_RZV2N_FEATURE_G31          BIT(0)
> > +#define SYS_RZV2N_FEATURE_C55          BIT(1)
> > +#define SYS_RZV2N_FEATURE_SEC          BIT(2)
> > +
> > +static void rzv2n_sys_print_id(struct device *dev,
> > +                              void __iomem *sysc_base,
> > +                              struct soc_device_attribute *soc_dev_attr)
> > +{
> > +       unsigned int part_number;
> > +       char features[75] = "";
> > +       u32 prr_val, mode_val;
> > +       u8 feature_flags;
> > +
> > +       prr_val = readl(sysc_base + SYS_LSI_PRR);
> > +       mode_val = readl(sysc_base + SYS_LSI_MODE);
> > +
> > +       /* Check GPU, ISP and Cryptographic configuration */
> > +       feature_flags = !(prr_val & SYS_LSI_PRR_GPU_DIS) ? SYS_RZV2N_FEATURE_G31 : 0;
> > +       feature_flags |= !(prr_val & SYS_LSI_PRR_ISP_DIS) ? SYS_RZV2N_FEATURE_C55 : 0;
> > +       feature_flags |= (mode_val & SYS_LSI_MODE_SEC_EN) ? SYS_RZV2N_FEATURE_SEC : 0;
> > +
> > +       part_number = 41;
> > +       if (feature_flags & SYS_RZV2N_FEATURE_G31)
> > +               part_number++;
> > +       if (feature_flags & SYS_RZV2N_FEATURE_C55)
> > +               part_number += 2;
> > +       if (feature_flags & SYS_RZV2N_FEATURE_SEC)
> > +               part_number += 4;
>
> The above construct can be simplified to
>
>     part_number = 41 + feature_flags;
>
Agreed.

> > +       if (feature_flags) {
> > +               unsigned int features_len = sizeof(features);
> > +
> > +               strscpy(features, "with ");
> > +               if (feature_flags & SYS_RZV2N_FEATURE_G31)
> > +                       strlcat(features, "GE3D (Mali-G31)", features_len);
> > +
> > +               if (feature_flags == (SYS_RZV2N_FEATURE_G31 |
> > +                                     SYS_RZV2N_FEATURE_C55 |
> > +                                     SYS_RZV2N_FEATURE_SEC))
> > +                       strlcat(features, ", ", features_len);
> > +               else if ((feature_flags & SYS_RZV2N_FEATURE_G31) &&
> > +                        (feature_flags & (SYS_RZV2N_FEATURE_C55 | SYS_RZV2N_FEATURE_SEC)))
> > +                       strlcat(features, " and ", features_len);
> > +
> > +               if (feature_flags & SYS_RZV2N_FEATURE_SEC)
> > +                       strlcat(features, "Cryptographic engine", features_len);
> > +
> > +               if ((feature_flags & SYS_RZV2N_FEATURE_SEC) &&
> > +                   (feature_flags & SYS_RZV2N_FEATURE_C55))
> > +                       strlcat(features, " and ", features_len);
> > +
> > +               if (feature_flags & SYS_RZV2N_FEATURE_C55)
> > +                       strlcat(features, "ISP (Mali-C55)", features_len);
> > +       }
>
> The above looks overly complicated to me.  What about handling it
> like on RZ/V2H?  I agree having 3x "with" doesn't look nice, but you
> could just drop all "with"s.
>
Ok, I will switch like below:

part_number = 41 + feature_flags;

dev_info(dev, "Detected Renesas %s %sn%d Rev %s%s%s%s%s\n",
soc_dev_attr->family,
               soc_dev_attr->soc_id, part_number,
soc_dev_attr->revision, feature_flags ?
               " with" : "", feature_flags & SYS_RZV2N_FEATURE_G31 ? "
GE3D (Mali-G31)" : "",
               feature_flags & SYS_RZV2N_FEATURE_SEC ? " Cryptographic
engine" : "",
               feature_flags & SYS_RZV2N_FEATURE_C55 ? " ISP (Mali-C55)" : "");


> > +       dev_info(dev, "Detected Renesas %s %sn%d Rev %s %s\n", soc_dev_attr->family,
> > +                soc_dev_attr->soc_id, part_number, soc_dev_attr->revision, features);
>
> This prints a trailing space if features is empty.
>
Agreed.

Cheers,
Prabhakar