Re: [PATCH v3 1/4] i3c: renesas: Switch to clk_bulk API and store clocks in private data

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

Hi Biju,
Thanks for you review!

On Wed, Dec 31, 2025 at 09:08:54AM +0000, Biju Das wrote:
> 
> 
> > -----Original Message-----
> > From: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
> > Sent: 31 December 2025 08:23
> > To: Tommaso Merciai <tomm.merciai@gmail.com>
> > Cc: linux-renesas-soc@vger.kernel.org; Biju Das <biju.das.jz@bp.renesas.com>; Tommaso Merciai
> > <tommaso.merciai.xr@bp.renesas.com>; wsa+renesas <wsa+renesas@sang-engineering.com>; Alexandre Belloni
> > <alexandre.belloni@bootlin.com>; Frank Li <Frank.Li@nxp.com>; Philipp Zabel <p.zabel@pengutronix.de>;
> > Geert Uytterhoeven <geert+renesas@glider.be>; magnus.damm <magnus.damm@gmail.com>; linux-
> > i3c@lists.infradead.org; linux-kernel@vger.kernel.org
> > Subject: [PATCH v3 1/4] i3c: renesas: Switch to clk_bulk API and store clocks in private data
> > 
> > Replace individual devm_clk_get_enabled() calls with the clk_bulk API and store the clock handles in
> > the driver's private data structure.
> > 
> > All clocks required by the controller are now acquired and enabled using
> > devm_clk_bulk_get_all_enabled(), removing the need for per-SoC clock handling and the
> > renesas_i3c_config data.
> > The TCLK is accessed via a fixed index in the bulk clock array.
> > 
> > Simplify the code and prepare the driver for upcoming suspend/resume support.
> > 
> > No functional change intended.
> > 
> > Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
> > ---
> > v2->v3:
> >  - Added define for TCLK index.
> >  - Use devm_clk_bulk_get_all_enabled() into renesas_i3c_probe().
> >  - Improved commit body.
> >  - Dropped unnecessary static const char * const renesas_i3c_clks[].
> >  - Removed the need for per-SoC clock handling and the renesas_i3c_config data.
> > 
> > v1->v2:
> >  - New patch.
> > 
> >  drivers/i3c/master/renesas-i3c.c | 43 ++++++++------------------------
> >  1 file changed, 11 insertions(+), 32 deletions(-)
> > 
> > diff --git a/drivers/i3c/master/renesas-i3c.c b/drivers/i3c/master/renesas-i3c.c
> > index 426a418f29b6..1b8f4be9ad67 100644
> > --- a/drivers/i3c/master/renesas-i3c.c
> > +++ b/drivers/i3c/master/renesas-i3c.c
> > @@ -198,6 +198,8 @@
> >  #define RENESAS_I3C_MAX_DEVS	8
> >  #define I2C_INIT_MSG		-1
> > 
> > +#define RENESAS_I3C_TCLK_IDX	1
> > +
> >  enum i3c_internal_state {
> >  	I3C_INTERNAL_STATE_DISABLED,
> >  	I3C_INTERNAL_STATE_CONTROLLER_IDLE,
> > @@ -259,7 +261,8 @@ struct renesas_i3c {
> >  	u8 addrs[RENESAS_I3C_MAX_DEVS];
> >  	struct renesas_i3c_xferqueue xferqueue;
> >  	void __iomem *regs;
> > -	struct clk *tclk;
> > +	struct clk_bulk_data *clks;
> > +	u8 num_clks;
> >  };
> > 
> >  struct renesas_i3c_i2c_dev_data {
> > @@ -272,10 +275,6 @@ struct renesas_i3c_irq_desc {
> >  	const char *desc;
> >  };
> > 
> > -struct renesas_i3c_config {
> > -	unsigned int has_pclkrw:1;
> > -};
> > -
> >  static inline void renesas_i3c_reg_update(void __iomem *reg, u32 mask, u32 val)  {
> >  	u32 data = readl(reg);
> > @@ -489,7 +488,7 @@ static int renesas_i3c_bus_init(struct i3c_master_controller *m)
> >  	int od_high_ticks, od_low_ticks, i2c_total_ticks;
> >  	int ret;
> > 
> > -	rate = clk_get_rate(i3c->tclk);
> > +	rate = clk_get_rate(i3c->clks[RENESAS_I3C_TCLK_IDX].clk);
> >  	if (!rate)
> >  		return -EINVAL;
> > 
> > @@ -1302,13 +1301,8 @@ static int renesas_i3c_probe(struct platform_device *pdev)  {
> >  	struct renesas_i3c *i3c;
> >  	struct reset_control *reset;
> > -	struct clk *clk;
> > -	const struct renesas_i3c_config *config = of_device_get_match_data(&pdev->dev);
> >  	int ret, i;
> > 
> > -	if (!config)
> > -		return -ENODATA;
> > -
> >  	i3c = devm_kzalloc(&pdev->dev, sizeof(*i3c), GFP_KERNEL);
> >  	if (!i3c)
> >  		return -ENOMEM;
> > @@ -1317,19 +1311,11 @@ static int renesas_i3c_probe(struct platform_device *pdev)
> >  	if (IS_ERR(i3c->regs))
> >  		return PTR_ERR(i3c->regs);
> > 
> > -	clk = devm_clk_get_enabled(&pdev->dev, "pclk");
> > -	if (IS_ERR(clk))
> > -		return PTR_ERR(clk);
> > -
> > -	if (config->has_pclkrw) {
> > -		clk = devm_clk_get_enabled(&pdev->dev, "pclkrw");
> 
> This still an optional clock for RZ/G3S.
> 
> > -		if (IS_ERR(clk))
> > -			return PTR_ERR(clk);
> > -	}
> > +	ret = devm_clk_bulk_get_all_enabled(&pdev->dev, &i3c->clks);
> 
> 
> This will break RZ/G3S as it does not have "pclkrw"

Please correct me if I'm wrong but:

Looking at DT binding (renesas,i3c.yaml) we have:

 - RZ/G3S (r9a08g045): Has only 2 clocks (pclk, tclk) - see maxItems: 2
 - RZ/G3E (r9a09g047): Has 3 clocks (pclk, tclk, pclkrw) - see minItems: 3

Then:

ret = devm_clk_bulk_get_all_enabled(&pdev->dev, &i3c->clks);

 - On RZ/G3S: Get 2 clocks → ret = 2, i3c->num_clks = 2
 - On RZ/G3E: Get 3 clocks → ret = 3, i3c->num_clks = 3

Then I think there is no need for config->has_pclkrw flag anymore.

And as:

clock-names:
  items:
    - const: pclk
    - const: tclk
    - const: pclkrw

tclk will be always 1 -> RENESAS_I3C_TCLK_IDX = 1

I'm missing somenthing?
Thanks in advance.

Kind Regards,
Tommaso


> 
> Cheers,
> Biju
> 
> > +	if (ret < 0)
> > +		return ret;
> > 
> > -	i3c->tclk = devm_clk_get_enabled(&pdev->dev, "tclk");
> > -	if (IS_ERR(i3c->tclk))
> > -		return PTR_ERR(i3c->tclk);
> > +	i3c->num_clks = ret;
> > 
> >  	reset = devm_reset_control_get_optional_exclusive_deasserted(&pdev->dev, "tresetn");
> >  	if (IS_ERR(reset))
> > @@ -1374,16 +1360,9 @@ static void renesas_i3c_remove(struct platform_device *pdev)
> >  	i3c_master_unregister(&i3c->base);
> >  }
> > 
> > -static const struct renesas_i3c_config empty_i3c_config = { -};
> > -
> > -static const struct renesas_i3c_config r9a09g047_i3c_config = {
> > -	.has_pclkrw = 1,
> > -};
> > -
> >  static const struct of_device_id renesas_i3c_of_ids[] = {
> > -	{ .compatible = "renesas,r9a08g045-i3c", .data = &empty_i3c_config },
> > -	{ .compatible = "renesas,r9a09g047-i3c", .data = &r9a09g047_i3c_config },
> > +	{ .compatible = "renesas,r9a08g045-i3c" },
> > +	{ .compatible = "renesas,r9a09g047-i3c" },
> >  	{ /* sentinel */ },
> >  };
> >  MODULE_DEVICE_TABLE(of, renesas_i3c_of_ids);
> > --
> > 2.43.0
> 

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