Re: [PATCH 4/5] i2c: riic: Pass register offsets and chip details as OF data

Lad, Prabhakar
2024-03-08T18:04:47Z

Hi Biju,

On Fri, Mar 8, 2024 at 5:36 PM Biju Das <biju.das.jz@bp.renesas.com> wrote:
>
> Hi Prabhakar,
>
> Thanks for the patch.
>
> > -----Original Message-----
> > From: Prabhakar <prabhakar.csengg@gmail.com>
> > Sent: Friday, March 8, 2024 5:27 PM
> > Subject: [PATCH 4/5] i2c: riic: Pass register offsets and chip details as OF data
> >
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >
> > With an increasing number of SoCs reusing this driver, each with slight variations in the RIIC IP, it
> > becomes necessary to support passing these details as OF data. This approach simplifies the extension
> > of the driver for other SoCs.
> >
> > This patch lays the groundwork for adding support for the Renesas RZ/V2H SoC.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > Reviewed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> > ---
> > drivers/i2c/busses/i2c-riic.c | 59 ++++++++++++++++++++++++++---------
> > 1 file changed, 44 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c index
> > 49a12f1ecdf9..3398d639b754 100644
> > --- a/drivers/i2c/busses/i2c-riic.c
> > +++ b/drivers/i2c/busses/i2c-riic.c
> > @@ -46,18 +46,6 @@
> > #include <linux/pm_runtime.h>
> > #include <linux/reset.h>
> >
> > -#define RIIC_ICCR1 0x00
> > -#define RIIC_ICCR2 0x04
> > -#define RIIC_ICMR1 0x08
> > -#define RIIC_ICMR3 0x10
> > -#define RIIC_ICSER 0x18
> > -#define RIIC_ICIER 0x1c
> > -#define RIIC_ICSR2 0x24
> > -#define RIIC_ICBRL 0x34
> > -#define RIIC_ICBRH 0x38
> > -#define RIIC_ICDRT 0x3c
> > -#define RIIC_ICDRR 0x40
> > -
> > #define ICCR1_ICE 0x80
> > #define ICCR1_IICRST 0x40
> > #define ICCR1_SOWP 0x10
> > @@ -87,6 +75,13 @@
> >
> > #define RIIC_INIT_MSG -1
> >
> > +#define RIIC_RZ_A_TYPE 0
>
> > +
> > +struct riic_of_data {
> > + u8 family;
>
> Do you need family as compatible have this information?
>
Yes this is added to future proof it, as the RZ/V2H SoC has some bit
differences in the slave address register as compared to RZ/A and
RZ/G2L. Comparing the family outside probe is not always preferred
hence this is added as part of OF data.

Cheers,
Prabhakar

> > + u8 regs[];
> > +};
> > +
> > struct riic_dev {
> > void __iomem *base;
> > u8 *buf;
> > @@ -94,6 +89,7 @@ struct riic_dev {
> > int bytes_left;
> > int err;
> > int is_last;
> > + const struct riic_of_data *info;
> > struct completion msg_done;
> > struct i2c_adapter adapter;
> > struct clk *clk;
> > @@ -105,14 +101,28 @@ struct riic_irq_desc {
> > char *name;
> > };
> >
> > +enum riic_reg_list {
> > + RIIC_ICCR1 = 0,
> > + RIIC_ICCR2,
> > + RIIC_ICMR1,
> > + RIIC_ICMR3,
> > + RIIC_ICSER,
> > + RIIC_ICIER,
> > + RIIC_ICSR2,
> > + RIIC_ICBRL,
> > + RIIC_ICBRH,
> > + RIIC_ICDRT,
> > + RIIC_ICDRR,
> > +};
> > +
> > static inline void riic_writeb_reg(u8 val, struct riic_dev *riic, u8 offset) {
> > - writeb(val, riic->base + offset);
> > + writeb(val, riic->base + riic->info->regs[offset]);
> > }
> >
> > static inline u8 riic_readb_reg(struct riic_dev *riic, u8 offset) {
> > - return readb(riic->base + offset);
> > + return readb(riic->base + riic->info->regs[offset]);
> > }
> >
> > static inline void riic_clear_set_bit(struct riic_dev *riic, u8 clear, u8 set, u8 reg) @@ -453,6
> > +463,8 @@ static int riic_i2c_probe(struct platform_device *pdev)
> > }
> > }
> >
> > + riic->info = of_device_get_match_data(&pdev->dev);
> > +
> > adap = &riic->adapter;
> > i2c_set_adapdata(adap, riic);
> > strscpy(adap->name, "Renesas RIIC adapter", sizeof(adap->name)); @@ -497,8 +509,25 @@ static void
> > riic_i2c_remove(struct platform_device *pdev)
> > pm_runtime_disable(&pdev->dev);
> > }
> >
> > +static const struct riic_of_data riic_rz_a_info = {
> > + .family = RIIC_RZ_A_TYPE,
> > + .regs = {
> > + [RIIC_ICCR1] = 0x00,
> > + [RIIC_ICCR2] = 0x04,
> > + [RIIC_ICMR1] = 0x08,
> > + [RIIC_ICMR3] = 0x10,
> > + [RIIC_ICSER] = 0x18,
> > + [RIIC_ICIER] = 0x1c,
> > + [RIIC_ICSR2] = 0x24,
> > + [RIIC_ICBRL] = 0x34,
> > + [RIIC_ICBRH] = 0x38,
> > + [RIIC_ICDRT] = 0x3c,
> > + [RIIC_ICDRR] = 0x40,
> > + },
> > +};
> > +
> > static const struct of_device_id riic_i2c_dt_ids[] = {
> > - { .compatible = "renesas,riic-rz", },
> > + { .compatible = "renesas,riic-rz", .data = &riic_rz_a_info },
> > { /* Sentinel */ },
> > };
> >
> > --
> > 2.34.1
> >
>