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Message-ID:
<TY3PR01MB113466E129D0970F0E2541F7B8686A@TY3PR01MB11346.jpnprd01.prod.outlook.com>
Date: Mon, 5 Jan 2026 18:06:19 +0000
From: Biju Das <biju.das.jz@...renesas.com>
To: Frank Li <Frank.li@....com>, Tommaso Merciai
<tommaso.merciai.xr@...renesas.com>
CC: Tommaso Merciai <tomm.merciai@...il.com>,
"linux-renesas-soc@...r.kernel.org" <linux-renesas-soc@...r.kernel.org>,
wsa+renesas <wsa+renesas@...g-engineering.com>, Alexandre Belloni
<alexandre.belloni@...tlin.com>, Philipp Zabel <p.zabel@...gutronix.de>,
Geert Uytterhoeven <geert+renesas@...der.be>, magnus.damm
<magnus.damm@...il.com>, "linux-i3c@...ts.infradead.org"
<linux-i3c@...ts.infradead.org>, "linux-kernel@...r.kernel.org"
<linux-kernel@...r.kernel.org>
Subject: RE: [PATCH v4 1/4] i3c: renesas: Switch to clk_bulk API and store
clocks in private data
Hi Frank Li,
> -----Original Message-----
> From: Frank Li <Frank.li@....com>
> Sent: 05 January 2026 17:12
> Subject: Re: [PATCH v4 1/4] i3c: renesas: Switch to clk_bulk API and store clocks in private data
>
> On Mon, Jan 05, 2026 at 11:49:59AM +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.
> >
> > 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.
> >
> > Reviewed-by: Biju Das <biju.das.jz@...renesas.com>
> > Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@...renesas.com>
> > ---
> > v3->v4:
> > - Collected Biju Das tag.
> >
> > 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");
> > - if (IS_ERR(clk))
> > - return PTR_ERR(clk);
> > - }
> > + ret = devm_clk_bulk_get_all_enabled(&pdev->dev, &i3c->clks);
> > + 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;
>
> Need check num_clks > RENESAS_I3C_TCLK_IDX to avoid outbound access at
> i3c->clks[RENESAS_I3C_TCLK_IDX].clk
I guess dt binding check validate this as well. Eg: a single clk defined
in the DT instead of minimum 2, will give DT warnings.
Do you expect additional check in C code as well?
Cheers,
Biju
> >
> > 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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