Re: [PATCH 2/2] clk: imx: support fsl,protected-clocks

From: Abel Vesa
Date: Mon Aug 15 2022 - 04:33:00 EST


On 22-08-15 11:36:32, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@xxxxxxx>
>
> For the clocks listed in fsl,protected-clocks, enable them to avoid
> Linux disable them. This will benifit root Linux and inmate cell run
> on top of Jailhouse hypervisor, and benifit AMP case.

Nitpick: s/benifit/benefit/

AMP?

>
> Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> ---
> drivers/clk/imx/clk-imx8mm.c | 2 ++
> drivers/clk/imx/clk-imx8mn.c | 2 ++
> drivers/clk/imx/clk-imx8mp.c | 2 ++
> drivers/clk/imx/clk-imx8mq.c | 2 ++
> drivers/clk/imx/clk.c | 21 +++++++++++++++++++++
> drivers/clk/imx/clk.h | 2 ++
> 6 files changed, 31 insertions(+)
>
> diff --git a/drivers/clk/imx/clk-imx8mm.c b/drivers/clk/imx/clk-imx8mm.c
> index b6d275855b36..24ddb1620bce 100644
> --- a/drivers/clk/imx/clk-imx8mm.c
> +++ b/drivers/clk/imx/clk-imx8mm.c
> @@ -611,6 +611,8 @@ static int imx8mm_clocks_probe(struct platform_device *pdev)
>
> imx_register_uart_clocks(4);
>
> + imx_clk_protect(dev, hws);
> +
> return 0;
>
> unregister_hws:
> diff --git a/drivers/clk/imx/clk-imx8mn.c b/drivers/clk/imx/clk-imx8mn.c
> index d37c45b676ab..57c486317d28 100644
> --- a/drivers/clk/imx/clk-imx8mn.c
> +++ b/drivers/clk/imx/clk-imx8mn.c
> @@ -604,6 +604,8 @@ static int imx8mn_clocks_probe(struct platform_device *pdev)
>
> imx_register_uart_clocks(4);
>
> + imx_clk_protect(dev, hws);
> +
> return 0;
>
> unregister_hws:
> diff --git a/drivers/clk/imx/clk-imx8mp.c b/drivers/clk/imx/clk-imx8mp.c
> index 652ae58c2735..a95862cc04a4 100644
> --- a/drivers/clk/imx/clk-imx8mp.c
> +++ b/drivers/clk/imx/clk-imx8mp.c
> @@ -713,6 +713,8 @@ static int imx8mp_clocks_probe(struct platform_device *pdev)
>
> imx_register_uart_clocks(4);
>
> + imx_clk_protect(dev, hws);
> +
> return 0;
> }
>
> diff --git a/drivers/clk/imx/clk-imx8mq.c b/drivers/clk/imx/clk-imx8mq.c
> index 882dcad4817d..2868e2390667 100644
> --- a/drivers/clk/imx/clk-imx8mq.c
> +++ b/drivers/clk/imx/clk-imx8mq.c
> @@ -603,6 +603,8 @@ static int imx8mq_clocks_probe(struct platform_device *pdev)
>
> imx_register_uart_clocks(4);
>
> + imx_clk_protect(dev, hws);
> +
> return 0;
>
> unregister_hws:
> diff --git a/drivers/clk/imx/clk.c b/drivers/clk/imx/clk.c
> index 5582f18dd632..307da8bd5243 100644
> --- a/drivers/clk/imx/clk.c
> +++ b/drivers/clk/imx/clk.c
> @@ -2,6 +2,7 @@
> #include <linux/bits.h>
> #include <linux/clk.h>
> #include <linux/clk-provider.h>
> +#include <linux/device.h>
> #include <linux/err.h>
> #include <linux/io.h>
> #include <linux/module.h>
> @@ -214,4 +215,24 @@ static int __init imx_clk_disable_uart(void)
> late_initcall_sync(imx_clk_disable_uart);
> #endif
>
> +int imx_clk_protect(struct device *dev, struct clk_hw * const clks[])
> +{
> + struct device_node *np = dev->of_node;
> + struct property *prop;
> + const __be32 *p;
> + u32 i;
> + int ret;
> +
> + of_property_for_each_u32(np, "fsl,protected-clocks", prop, p, i) {
> + ret = clk_prepare_enable(clks[i]->clk);

I might be wrong here, but wouldn't CLK_IGNORE_UNUSED have the same effect?

I don't think we should circumvent that by adding vendor specific dts properties.

> + if (ret) {
> + dev_err(dev, "failed to enable %s\n", clk_hw_get_name(clks[i]));
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(imx_clk_protect);
> +
> MODULE_LICENSE("GPL v2");
> diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h
> index dd49f90110e8..3f8099190b99 100644
> --- a/drivers/clk/imx/clk.h
> +++ b/drivers/clk/imx/clk.h
> @@ -22,6 +22,8 @@ void imx_mmdc_mask_handshake(void __iomem *ccm_base, unsigned int chn);
> void imx_unregister_clocks(struct clk *clks[], unsigned int count);
> void imx_unregister_hw_clocks(struct clk_hw *hws[], unsigned int count);
>
> +int imx_clk_protect(struct device *dev, struct clk_hw * const clks[]);
> +
> extern void imx_cscmr1_fixup(u32 *val);
>
> enum imx_pllv1_type {
> --
> 2.37.1
>