linux-kernel - Re: [PATCH v4 1/4] i3c: renesas: Switch to clk_bulk API and store clocks in private data

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Message-ID: <aVvw3pjhphnVv7g2@lizhi-Precision-Tower-5810>
Date: Mon, 5 Jan 2026 12:11:58 -0500
From: Frank Li <Frank.li@....com>
To: Tommaso Merciai <tommaso.merciai.xr@...renesas.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>,
	Geert Uytterhoeven <geert+renesas@...der.be>,
	Magnus Damm <magnus.damm@...il.com>, linux-i3c@...ts.infradead.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

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

Frank

>
>  	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
>