Re: [PATCH v2 4/9] memory: Add STM32 Octo Memory Manager driver

[Philipp Zabel <p.zabel@pengutronix.de>]

On Di, 2025-01-28 at 09:17 +0100, patrice.chotard@foss.st.com wrote:
> From: Patrice Chotard <patrice.chotard@foss.st.com>
> 
> Octo Memory Manager driver (OMM) manages:
>   - the muxing between 2 OSPI busses and 2 output ports.
>     There are 4 possible muxing configurations:
>       - direct mode (no multiplexing): OSPI1 output is on port 1 and OSPI2
>         output is on port 2
>       - OSPI1 and OSPI2 are multiplexed over the same output port 1
>       - swapped mode (no multiplexing), OSPI1 output is on port 2,
>         OSPI2 output is on port 1
>       - OSPI1 and OSPI2 are multiplexed over the same output port 2
>   - the split of the memory area shared between the 2 OSPI instances.
>   - chip select selection override.
>   - the time between 2 transactions in multiplexed mode.
>   - check firewall access.
> 
> Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
> Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
> ---
>  drivers/memory/Kconfig     |  17 ++
>  drivers/memory/Makefile    |   1 +
>  drivers/memory/stm32_omm.c | 509 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 527 insertions(+)
>  create mode 100644 drivers/memory/stm32_omm.c
> 
[...]
> diff --git a/drivers/memory/stm32_omm.c b/drivers/memory/stm32_omm.c
> new file mode 100644
> index 000000000000..6f20fe0183ec
> --- /dev/null
> +++ b/drivers/memory/stm32_omm.c
> @@ -0,0 +1,509 @@
[...]
> +static int stm32_omm_configure(struct device *dev)
> +{
> +	struct stm32_omm *omm = dev_get_drvdata(dev);
> +	struct reset_control *rstc;
> +	unsigned long clk_rate, clk_rate_max = 0;
> +	int ret;
> +	u8 i;
> +	u32 mux = 0;
> +	u32 cssel_ovr = 0;
> +	u32 req2ack = 0;
> +
> +	omm->clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(omm->clk)) {
> +		dev_err(dev, "Failed to get OMM clock (%ld)\n",
> +			PTR_ERR(omm->clk));
> +
> +		return PTR_ERR(omm->clk);
> +	}
> +
> +	ret = pm_runtime_resume_and_get(dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* parse children's clock */
> +	for (i = 0; i < omm->nb_child; i++) {
> +		clk_rate = clk_get_rate(omm->child[i].clk);
> +		if (!clk_rate) {
> +			dev_err(dev, "Invalid clock rate\n");
> +			goto err_clk_disable;
> +		}
> +
> +		if (clk_rate > clk_rate_max)
> +			clk_rate_max = clk_rate;
> +	}
> +
> +	rstc = devm_reset_control_get_optional(dev, NULL);

Please use devm_reset_control_get_optional_exclusive() directly.

regards
Philipp