[PATCH v3 3/4] clocksource/drivers/renesas-ostm: Add RZ/G2L OSTM support

[Daniel Lezcano]

On 12/11/2021 19:44, Biju Das wrote:
> RZ/G2L SoC has Generic Timer Module(a.k.a OSTM) which needs to
> deassert the reset line before accessing any registers.
> 
> This patch adds an entry point for RZ/G2L so that we can deassert
> the reset line in probe callback.

What is the connection between adding the reset line control and the
platform driver at the end of the driver ?

> Signed-off-by: Biju Das <biju.das.jz at bp.renesas.com>
> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj at bp.renesas.com>
> ---
> v2->v3:
>  * Added reset_control_put() on error path.
>  * enabled suppress_bind_attrs in ostm_device_driver structure
> v1->v2:
>  * Added reset handling inside ostm_init
>  * Used same compatible for builtin driver aswell
> ---
>  drivers/clocksource/renesas-ostm.c | 39 +++++++++++++++++++++++++++++-
>  1 file changed, 38 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/clocksource/renesas-ostm.c b/drivers/clocksource/renesas-ostm.c
> index 3d06ba66008c..21d1392637b8 100644
> --- a/drivers/clocksource/renesas-ostm.c
> +++ b/drivers/clocksource/renesas-ostm.c
> @@ -9,6 +9,8 @@
>  #include <linux/clk.h>
>  #include <linux/clockchips.h>
>  #include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
>  #include <linux/sched_clock.h>
>  #include <linux/slab.h>
>  
> @@ -159,6 +161,7 @@ static int __init ostm_init_clkevt(struct timer_of *to)
>  
>  static int __init ostm_init(struct device_node *np)
>  {
> +	struct reset_control *rstc;
>  	struct timer_of *to;
>  	int ret;
>  
> @@ -166,6 +169,14 @@ static int __init ostm_init(struct device_node *np)
>  	if (!to)
>  		return -ENOMEM;
>  
> +	rstc = of_reset_control_get_optional_exclusive(np, NULL);
> +	if (IS_ERR(rstc)) {
> +		ret = PTR_ERR(rstc);
> +		goto err_free;
> +	}
> +
> +	reset_control_deassert(rstc);
> +
>  	to->flags = TIMER_OF_BASE | TIMER_OF_CLOCK;
>  	if (system_clock) {
>  		/*
> @@ -178,7 +189,7 @@ static int __init ostm_init(struct device_node *np)
>  
>  	ret = timer_of_init(np, to);
>  	if (ret)
> -		goto err_free;
> +		goto err_reset;
>  
>  	/*
>  	 * First probed device will be used as system clocksource. Any
> @@ -203,9 +214,35 @@ static int __init ostm_init(struct device_node *np)
>  
>  err_cleanup:
>  	timer_of_cleanup(to);
> +err_reset:
> +	reset_control_assert(rstc);
> +	reset_control_put(rstc);
>  err_free:
>  	kfree(to);
>  	return ret;
>  }
>  
>  TIMER_OF_DECLARE(ostm, "renesas,ostm", ostm_init);
> +
> +#ifdef CONFIG_ARCH_R9A07G044
> +static int __init ostm_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +
> +	return ostm_init(dev->of_node);
> +}
> +
> +static const struct of_device_id ostm_of_table[] = {
> +	{ .compatible = "renesas,ostm", },
> +	{ /* sentinel */ }
> +};
> +
> +static struct platform_driver ostm_device_driver = {
> +	.driver = {
> +		.name = "renesas_ostm",
> +		.of_match_table = of_match_ptr(ostm_of_table),
> +		.suppress_bind_attrs = true,
> +	},
> +};
> +builtin_platform_driver_probe(ostm_device_driver, ostm_probe);
> +#endif
> 


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