linux-kernel - Re: [PATCH v2 1/4] i3c: renesas: Switch to clk_bulk API and store clocks in private data

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Message-ID: <aVP81n7yRgeHz3FX@tom-desktop>
Date: Tue, 30 Dec 2025 17:24:54 +0100
From: Tommaso Merciai <tommaso.merciai.xr@...renesas.com>
To: Frank Li <Frank.li@....com>
Cc: tomm.merciai@...il.com, linux-renesas-soc@...r.kernel.org,
	biju.das.jz@...renesas.com,
	Wolfram Sang <wsa+renesas@...g-engineering.com>,
	Alexandre Belloni <alexandre.belloni@...tlin.com>,
	Philipp Zabel <p.zabel@...gutronix.de>,
	linux-i3c@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/4] i3c: renesas: Switch to clk_bulk API and store
 clocks in private data

Hi Frank,
Thanks for your review!


On Tue, Dec 30, 2025 at 10:44:02AM -0500, Frank Li wrote:
> On Tue, Dec 30, 2025 at 11:39:36AM +0100, Tommaso Merciai wrote:
> > Replace individual devm_clk_get_enabled() calls with the clk_bulk API
> > and store the clock handles in the driver's private data structure.
> >
> > This simplifies the code, and prepares the driver for upcoming
> > suspend/resume support.
> >
> > No functional change intended.
> >
> > Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@...renesas.com>
> > ---
> > v1->v2:
> >  - New patch.
> >
> >  drivers/i3c/master/renesas-i3c.c | 42 +++++++++++++++++++++-----------
> >  1 file changed, 28 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/i3c/master/renesas-i3c.c b/drivers/i3c/master/renesas-i3c.c
> > index 426a418f29b6..8ef6ff06df90 100644
> > --- a/drivers/i3c/master/renesas-i3c.c
> > +++ b/drivers/i3c/master/renesas-i3c.c
> > @@ -259,7 +259,8 @@ 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[3];
> > +	u8 num_clks;
> >  };
> >
> >  struct renesas_i3c_i2c_dev_data {
> > @@ -276,6 +277,10 @@ struct renesas_i3c_config {
> >  	unsigned int has_pclkrw:1;
> >  };
> >
> > +static const char * const renesas_i3c_clks[] = {
> > +	"pclk", "tclk", "pclkrw"
> > +};
> > +
> >  static inline void renesas_i3c_reg_update(void __iomem *reg, u32 mask, u32 val)
> >  {
> >  	u32 data = readl(reg);
> > @@ -489,7 +494,7 @@ 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[1].clk);
> 
> Can you use macro of variable replace hardcode "1"

Ack! I'd go for:

	i3c->rate = clk_get_rate(i3c->clks[RENESAS_I3C_TCLK_IDX].clk);

in v3, thanks.

> 
> >  	if (!rate)
> >  		return -EINVAL;
> >
> > @@ -1298,11 +1303,17 @@ static const struct renesas_i3c_irq_desc renesas_i3c_irqs[] = {
> >  	{ .name = "nack", .isr = renesas_i3c_tend_isr, .desc = "i3c-nack" },
> >  };
> >
> > +static void renesas_i3c_clk_bulk_disable_unprepare(void *data)
> > +{
> > +	struct renesas_i3c *i3c = data;
> > +
> > +	clk_bulk_disable_unprepare(i3c->num_clks, i3c->clks);
> > +}
> > +
> >  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;
> >
> > @@ -1317,19 +1328,22 @@ 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);
> > +	i3c->num_clks = config->has_pclkrw ? 3 : 2;
> >
> > -	if (config->has_pclkrw) {
> > -		clk = devm_clk_get_enabled(&pdev->dev, "pclkrw");
> > -		if (IS_ERR(clk))
> > -			return PTR_ERR(clk);
> > -	}
> > +	for (i = 0; i < i3c->num_clks; i++)
> > +		i3c->clks[i].id = renesas_i3c_clks[i];
> >
> > -	i3c->tclk = devm_clk_get_enabled(&pdev->dev, "tclk");
> > -	if (IS_ERR(i3c->tclk))
> > -		return PTR_ERR(i3c->tclk);
> > +	ret = devm_clk_bulk_get(&pdev->dev, i3c->num_clks, i3c->clks);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = clk_bulk_prepare_enable(i3c->num_clks, i3c->clks);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = devm_add_action_or_reset(&pdev->dev, renesas_i3c_clk_bulk_disable_unprepare, i3c);
> > +	if (ret)
> > +		return ret;
> 
> Can you use devm_clk_bulk_get_all_enabled()? all dts already verified
> by dt-schema.

Ack! I'd got for:

	i3c->num_clks = config->has_pclkrw ? 3 : 2;

	for (i = 0; i < i3c->num_clks; i++)
		i3c->clks[i].id = renesas_i3c_clks[i];

	ret = devm_clk_bulk_get_all_enabled(&pdev->dev, &i3c->clks);
	if (ret < 0)
		return ret;

In v3, Thanks.

> 
> Frank
> 
> >
> >  	reset = devm_reset_control_get_optional_exclusive_deasserted(&pdev->dev, "tresetn");
> >  	if (IS_ERR(reset))
> > --
> > 2.43.0
> >

Kind Regards,
Tommaso