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Date:   Fri, 16 Aug 2019 15:11:29 +0200
From:   Simon Horman <horms@verge.net.au>
To:     Geert Uytterhoeven <geert+renesas@glider.be>
Cc:     Daniel Lezcano <daniel.lezcano@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Jacopo Mondi <jacopo+renesas@jmondi.org>,
        Chris Brandt <Chris.Brandt@renesas.com>,
        linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 3/3] clocksource/drivers/ostm: Use unique device name
 instead of ostm
Message-ID: <20190816131129.eh4jgsdle77kulaq@verge.net.au>
References: <20190807084635.24173-1-geert+renesas@glider.be>
 <20190807084635.24173-4-geert+renesas@glider.be>
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In-Reply-To: <20190807084635.24173-4-geert+renesas@glider.be>
Organisation: Horms Solutions BV
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On Wed, Aug 07, 2019 at 10:46:35AM +0200, Geert Uytterhoeven wrote:
> Currently all OSTM devices are called "ostm", also in kernel messages.
> 
> As there can be multiple instances in an SoC, this can confuse the user.
> Hence construct a unique name from the DT node name, like is done for
> platform devices.
> 
> On RSK+RZA1, the boot log changes like:
> 
>     -clocksource: ostm: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 57352151442 ns
>     +clocksource: ostm fcfec000.timer: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 57352151442 ns
>      sched_clock: 32 bits at 33MHz, resolution 30ns, wraps every 64440619504ns
>     -ostm: used for clocksource
>     -ostm: used for clock events
>     +ostm fcfec000.timer: used for clocksource
>     +ostm fcfec400.timer: used for clock events
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> v3:
>   - Make the name format similar to the one used for platform devices,
>   - Use kasprintf() instead of buffer size guessing,
>   - Use a real example from rskrza1.
> 
> v2 (by Jacopo):
>   - Use np->full_name.
> ---
>  drivers/clocksource/renesas-ostm.c | 45 ++++++++++++++++++++----------
>  1 file changed, 30 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/clocksource/renesas-ostm.c b/drivers/clocksource/renesas-ostm.c
> index 1e22e54d7b0df40d..659e3ec7b86714e3 100644
> --- a/drivers/clocksource/renesas-ostm.c
> +++ b/drivers/clocksource/renesas-ostm.c
> @@ -25,6 +25,7 @@
>   */
>  
>  struct ostm_device {
> +	const char *name;
>  	void __iomem *base;
>  	unsigned long ticks_per_jiffy;
>  	struct clock_event_device ced;
> @@ -79,9 +80,8 @@ static int __init ostm_init_clksrc(struct ostm_device *ostm, unsigned long rate)
>  	writeb(CTL_FREERUN, ostm->base + OSTM_CTL);
>  	writeb(TS, ostm->base + OSTM_TS);
>  
> -	return clocksource_mmio_init(ostm->base + OSTM_CNT,
> -			"ostm", rate,
> -			300, 32, clocksource_mmio_readl_up);
> +	return clocksource_mmio_init(ostm->base + OSTM_CNT, ostm->name, rate,
> +				     300, 32, clocksource_mmio_readl_up);
>  }
>  
>  static u64 notrace ostm_read_sched_clock(void)
> @@ -161,15 +161,14 @@ static int __init ostm_init_clkevt(struct ostm_device *ostm, unsigned int irq,
>  	struct clock_event_device *ced = &ostm->ced;
>  	int ret = -ENXIO;
>  
> -	ret = request_irq(irq, ostm_timer_interrupt,
> -			  IRQF_TIMER | IRQF_IRQPOLL,
> -			  "ostm", ostm);
> +	ret = request_irq(irq, ostm_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL,
> +			  ostm->name, ostm);
>  	if (ret) {
> -		pr_err("ostm: failed to request irq\n");
> +		pr_err("%s: Failed to request irq\n", ostm->name);
>  		return ret;
>  	}
>  
> -	ced->name = "ostm";
> +	ced->name = ostm->name;
>  	ced->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC;
>  	ced->set_state_shutdown = ostm_shutdown;
>  	ced->set_state_periodic = ostm_set_periodic;
> @@ -187,6 +186,7 @@ static int __init ostm_init(struct device_node *np)
>  {
>  	struct clk *ostm_clk = NULL;
>  	struct ostm_device *ostm;
> +	struct resource res;
>  	unsigned long rate;
>  	unsigned int irq;
>  	int ret;
> @@ -195,22 +195,35 @@ static int __init ostm_init(struct device_node *np)
>  	if (!ostm)
>  		return -ENOMEM;
>  
> -	ostm->base = of_iomap(np, 0);
> -	if (!ostm->base) {
> +	ret = of_address_to_resource(np, 0, &res);
> +	if (ret) {
> +		pr_err("ostm: Failed to obtain I/O memory\n");
> +		goto err_free;
> +	}
> +
> +	ostm->name = kasprintf(GFP_KERNEL, "ostm %llx.%s",
> +			       (unsigned long long)res.start, np->name);

I'm not sure, but looking at printk-formats.rst it seems that
%pa[p] as a format specifier for resource_size_t. If so it may
allow dropping the cast above.

> +	if (!ostm->name) {
>  		ret = -ENOMEM;
>  		goto err_free;
>  	}
>  
> +	ostm->base = ioremap(res.start, resource_size(&res));
> +	if (!ostm->base) {
> +		ret = -ENOMEM;
> +		goto err_free_name;
> +	}
> +
>  	irq = irq_of_parse_and_map(np, 0);
>  	if (!irq) {
> -		pr_err("ostm: Failed to get irq\n");
> +		pr_err("%s: Failed to get irq\n", ostm->name);
>  		ret = -EINVAL;
>  		goto err_unmap;
>  	}
>  
>  	ostm_clk = of_clk_get(np, 0);
>  	if (IS_ERR(ostm_clk)) {
> -		pr_err("ostm: Failed to get clock\n");
> +		pr_err("%s: Failed to get clock\n", ostm->name);
>  		ostm_clk = NULL;
>  		ret = PTR_ERR(ostm_clk);
>  		goto err_unmap;
> @@ -218,7 +231,7 @@ static int __init ostm_init(struct device_node *np)
>  
>  	ret = clk_prepare_enable(ostm_clk);
>  	if (ret) {
> -		pr_err("ostm: Failed to enable clock\n");
> +		pr_err("%s: Failed to enable clock\n", ostm->name);
>  		goto err_clk_put;
>  	}
>  
> @@ -235,13 +248,13 @@ static int __init ostm_init(struct device_node *np)
>  			goto err_clk_disable;
>  
>  		ostm_init_sched_clock(ostm, rate);
> -		pr_info("ostm: used for clocksource\n");
> +		pr_info("%s: used for clocksource\n", ostm->name);
>  	} else {
>  		ret = ostm_init_clkevt(ostm, irq, rate);
>  		if (ret)
>  			goto err_clk_disable;
>  
> -		pr_info("ostm: used for clock events\n");
> +		pr_info("%s: used for clock events\n", ostm->name);
>  	}
>  
>  	return 0;
> @@ -252,6 +265,8 @@ static int __init ostm_init(struct device_node *np)
>  	clk_put(ostm_clk);
>  err_unmap:
>  	iounmap(ostm->base);
> +err_free_name:
> +	kfree(ostm->name);
>  err_free:
>  	kfree(ostm);
>  	return ret;
> -- 
> 2.17.1
>