Re: [PATCH v4 2/4] i3c: renesas: Store clock rate and reset controls in struct renesas_i3c

[Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>]

Hi Biju,
Thanks for your review.

On Mon, Jan 05, 2026 at 10:53:29AM +0000, Biju Das wrote:
> Hi Tommaso Merciai,
> 
> > -----Original Message-----
> > From: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
> > Sent: 05 January 2026 10:50
> > Subject: [PATCH v4 2/4] i3c: renesas: Store clock rate and reset controls in struct renesas_i3c
> > 
> > Update the struct renesas_i3c to store the clock rate, presetn and tresetn handlers. Replace local
> > usage of the clock rate and reset controls with these structure fields.
> > 
> > Simplify the code and prepare the driver for upcoming suspend/resume support.
> > 
> > No functional change intended.
> > 
> > Reviewed-by: Frank Li <Frank.Li@nxp.com>
> > Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
> > ---
> > v3->v4:
> >  - No changes.
> > 
> > v2->v3:
> >  - Collected FLi tag.
> >  - Improved commit body.
> > 
> > v1->v2:
> >  - New patch.
> > 
> >  drivers/i3c/master/renesas-i3c.c | 39 ++++++++++++++++----------------
> >  1 file changed, 20 insertions(+), 19 deletions(-)
> > 
> > diff --git a/drivers/i3c/master/renesas-i3c.c b/drivers/i3c/master/renesas-i3c.c
> > index 1b8f4be9ad67..7359f71f78dd 100644
> > --- a/drivers/i3c/master/renesas-i3c.c
> > +++ b/drivers/i3c/master/renesas-i3c.c
> > @@ -258,11 +258,14 @@ struct renesas_i3c {
> >  	u32 free_pos;
> >  	u32 i2c_STDBR;
> >  	u32 i3c_STDBR;
> > +	unsigned long rate;
> >  	u8 addrs[RENESAS_I3C_MAX_DEVS];
> >  	struct renesas_i3c_xferqueue xferqueue;
> >  	void __iomem *regs;
> >  	struct clk_bulk_data *clks;
> >  	u8 num_clks;
> > +	struct reset_control *presetn;
> > +	struct reset_control *tresetn;
> 
> Can this be above num_clks to avoid padding?

Ack. Thanks.

Kind Regards,
Tommaso

> 
> Cheers,
> Biju
> 
> >  };
> > 
> >  struct renesas_i3c_i2c_dev_data {
> > @@ -482,22 +485,21 @@ static int renesas_i3c_bus_init(struct i3c_master_controller *m)
> >  	struct i3c_bus *bus = i3c_master_get_bus(m);
> >  	struct i3c_device_info info = {};
> >  	struct i2c_timings t;
> > -	unsigned long rate;
> >  	u32 double_SBR, val;
> >  	int cks, pp_high_ticks, pp_low_ticks, i3c_total_ticks;
> >  	int od_high_ticks, od_low_ticks, i2c_total_ticks;
> >  	int ret;
> > 
> > -	rate = clk_get_rate(i3c->clks[RENESAS_I3C_TCLK_IDX].clk);
> > -	if (!rate)
> > +	i3c->rate = clk_get_rate(i3c->clks[RENESAS_I3C_TCLK_IDX].clk);
> > +	if (!i3c->rate)
> >  		return -EINVAL;
> > 
> >  	ret = renesas_i3c_reset(i3c);
> >  	if (ret)
> >  		return ret;
> > 
> > -	i2c_total_ticks = DIV_ROUND_UP(rate, bus->scl_rate.i2c);
> > -	i3c_total_ticks = DIV_ROUND_UP(rate, bus->scl_rate.i3c);
> > +	i2c_total_ticks = DIV_ROUND_UP(i3c->rate, bus->scl_rate.i2c);
> > +	i3c_total_ticks = DIV_ROUND_UP(i3c->rate, bus->scl_rate.i3c);
> > 
> >  	i2c_parse_fw_timings(&m->dev, &t, true);
> > 
> > @@ -510,7 +512,7 @@ static int renesas_i3c_bus_init(struct i3c_master_controller *m)
> >  			pp_high_ticks = ((i3c_total_ticks * 5) / 10);
> >  		else
> >  			pp_high_ticks = DIV_ROUND_UP(I3C_BUS_THIGH_MIXED_MAX_NS,
> > -						     NSEC_PER_SEC / rate);
> > +						     NSEC_PER_SEC / i3c->rate);
> >  		pp_low_ticks = i3c_total_ticks - pp_high_ticks;
> > 
> >  		if ((od_low_ticks / 2) <= 0xFF && pp_low_ticks < 0x3F) @@ -518,7 +520,7 @@ static int
> > renesas_i3c_bus_init(struct i3c_master_controller *m)
> > 
> >  		i2c_total_ticks /= 2;
> >  		i3c_total_ticks /= 2;
> > -		rate /= 2;
> > +		i3c->rate /= 2;
> >  	}
> > 
> >  	/* SCL clock period calculation in Open-drain mode */ @@ -539,8 +541,8 @@ static int
> > renesas_i3c_bus_init(struct i3c_master_controller *m)
> >  			STDBR_SBRLP(pp_low_ticks) |
> >  			STDBR_SBRHP(pp_high_ticks);
> > 
> > -	od_low_ticks -= t.scl_fall_ns / (NSEC_PER_SEC / rate) + 1;
> > -	od_high_ticks -= t.scl_rise_ns / (NSEC_PER_SEC / rate) + 1;
> > +	od_low_ticks -= t.scl_fall_ns / (NSEC_PER_SEC / i3c->rate) + 1;
> > +	od_high_ticks -= t.scl_rise_ns / (NSEC_PER_SEC / i3c->rate) + 1;
> >  	i3c->i2c_STDBR = (double_SBR ? STDBR_DSBRPO : 0) |
> >  			STDBR_SBRLO(double_SBR, od_low_ticks) |
> >  			STDBR_SBRHO(double_SBR, od_high_ticks) | @@ -591,13 +593,13 @@ static int
> > renesas_i3c_bus_init(struct i3c_master_controller *m)
> >  	renesas_set_bit(i3c->regs, SCSTRCTL, SCSTRCTL_ACKTWE);
> > 
> >  	/* Bus condition timing */
> > -	val = DIV_ROUND_UP(I3C_BUS_TBUF_MIXED_FM_MIN_NS, NSEC_PER_SEC / rate);
> > +	val = DIV_ROUND_UP(I3C_BUS_TBUF_MIXED_FM_MIN_NS, NSEC_PER_SEC /
> > +i3c->rate);
> >  	renesas_writel(i3c->regs, BFRECDT, BFRECDT_FRECYC(val));
> > 
> > -	val = DIV_ROUND_UP(I3C_BUS_TAVAL_MIN_NS, NSEC_PER_SEC / rate);
> > +	val = DIV_ROUND_UP(I3C_BUS_TAVAL_MIN_NS, NSEC_PER_SEC / i3c->rate);
> >  	renesas_writel(i3c->regs, BAVLCDT, BAVLCDT_AVLCYC(val));
> > 
> > -	val = DIV_ROUND_UP(I3C_BUS_TIDLE_MIN_NS, NSEC_PER_SEC / rate);
> > +	val = DIV_ROUND_UP(I3C_BUS_TIDLE_MIN_NS, NSEC_PER_SEC / i3c->rate);
> >  	renesas_writel(i3c->regs, BIDLCDT, BIDLCDT_IDLCYC(val));
> > 
> >  	ret = i3c_master_get_free_addr(m, 0);
> > @@ -1300,7 +1302,6 @@ static const struct renesas_i3c_irq_desc renesas_i3c_irqs[] = {  static int
> > renesas_i3c_probe(struct platform_device *pdev)  {
> >  	struct renesas_i3c *i3c;
> > -	struct reset_control *reset;
> >  	int ret, i;
> > 
> >  	i3c = devm_kzalloc(&pdev->dev, sizeof(*i3c), GFP_KERNEL); @@ -1317,14 +1318,14 @@ static int
> > renesas_i3c_probe(struct platform_device *pdev)
> > 
> >  	i3c->num_clks = ret;
> > 
> > -	reset = devm_reset_control_get_optional_exclusive_deasserted(&pdev->dev, "tresetn");
> > -	if (IS_ERR(reset))
> > -		return dev_err_probe(&pdev->dev, PTR_ERR(reset),
> > +	i3c->tresetn = devm_reset_control_get_optional_exclusive_deasserted(&pdev->dev, "tresetn");
> > +	if (IS_ERR(i3c->tresetn))
> > +		return dev_err_probe(&pdev->dev, PTR_ERR(i3c->tresetn),
> >  				     "Error: missing tresetn ctrl\n");
> > 
> > -	reset = devm_reset_control_get_optional_exclusive_deasserted(&pdev->dev, "presetn");
> > -	if (IS_ERR(reset))
> > -		return dev_err_probe(&pdev->dev, PTR_ERR(reset),
> > +	i3c->presetn = devm_reset_control_get_optional_exclusive_deasserted(&pdev->dev, "presetn");
> > +	if (IS_ERR(i3c->presetn))
> > +		return dev_err_probe(&pdev->dev, PTR_ERR(i3c->presetn),
> >  				     "Error: missing presetn ctrl\n");
> > 
> >  	spin_lock_init(&i3c->xferqueue.lock);
> > --
> > 2.43.0
> 

-- 
linux-i3c mailing list
linux-i3c@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-i3c