[PATCH v3 10/19] clocksource: sh_tmu: Add DT support

[Simon Horman]

Hi Laurent,

thanks for your patch.

On Sat, Jun 14, 2014 at 06:23:32PM +0200, Laurent Pinchart wrote:
> Document DT bindings and parse them in the TMU driver.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>

[snip]

> diff --git a/drivers/clocksource/sh_tmu.c b/drivers/clocksource/sh_tmu.c
> index ef8fb0b..2ece4ab 100644
> --- a/drivers/clocksource/sh_tmu.c
> +++ b/drivers/clocksource/sh_tmu.c
> @@ -24,6 +24,7 @@
>  #include <linux/ioport.h>
>  #include <linux/irq.h>
>  #include <linux/module.h>
> +#include <linux/of.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_domain.h>
>  #include <linux/pm_runtime.h>
> @@ -509,23 +510,46 @@ static int sh_tmu_map_memory(struct sh_tmu_device *tmu)
>  	return 0;
>  }
>  
> +static int sh_tmu_parse_dt(struct sh_tmu_device *tmu)
> +{
> +	struct device_node *np = tmu->pdev->dev.of_node;
> +
> +	tmu->num_channels = 3;
> +	of_property_read_u32(np, "#renesas,channels", &tmu->num_channels);
> +
> +	if (tmu->num_channels != 2 && tmu->num_channels != 3) {
> +		dev_err(&tmu->pdev->dev, "invalid number of channels %u\n",
> +			tmu->num_channels);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
>  static int sh_tmu_setup(struct sh_tmu_device *tmu, struct platform_device *pdev)
>  {
> -	struct sh_timer_config *cfg = pdev->dev.platform_data;
>  	const struct platform_device_id *id = pdev->id_entry;
>  	unsigned int i;
>  	int ret;
>  
> -	if (!cfg) {
> -		dev_err(&tmu->pdev->dev, "missing platform data\n");
> -		return -ENXIO;
> -	}
> -
>  	tmu->pdev = pdev;
>  	tmu->model = id->driver_data;
>  
>  	raw_spin_lock_init(&tmu->lock);
>  
> +	if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
> +		ret = sh_tmu_parse_dt(tmu);
> +		if (ret < 0)
> +			return ret;
> +	} else if (pdev->dev.platform_data) {
> +		struct sh_timer_config *cfg = pdev->dev.platform_data;
> +
> +		tmu->num_channels = hweight8(cfg->channels_mask);
> +	} else {
> +		dev_err(&tmu->pdev->dev, "missing platform data\n");
> +		return -ENXIO;
> +	}
> +
>  	/* Get hold of clock. */
>  	tmu->clk = clk_get(&tmu->pdev->dev, "fck");
>  	if (IS_ERR(tmu->clk)) {

[snip]

I had a bit of trouble running this code and after some investigation
it seems to me that in the case of using DT id will be NULL and
thus things do not go well when id->driver_data is accessed.

The following incremental patch resolved the problem for me.

diff --git a/drivers/clocksource/sh_tmu.c b/drivers/clocksource/sh_tmu.c
index 2ece4ab..3f90927 100644
--- a/drivers/clocksource/sh_tmu.c
+++ b/drivers/clocksource/sh_tmu.c
@@ -523,6 +523,8 @@ static int sh_tmu_parse_dt(struct sh_tmu_device *tmu)
 		return -EINVAL;
 	}
 
+	tmu->model = SH_TMU;
+
 	return 0;
 }
 
@@ -533,7 +535,6 @@ static int sh_tmu_setup(struct sh_tmu_device *tmu, struct platform_device *pdev)
 	int ret;
 
 	tmu->pdev = pdev;
-	tmu->model = id->driver_data;
 
 	raw_spin_lock_init(&tmu->lock);
 
@@ -545,6 +546,7 @@ static int sh_tmu_setup(struct sh_tmu_device *tmu, struct platform_device *pdev)
 		struct sh_timer_config *cfg = pdev->dev.platform_data;
 
 		tmu->num_channels = hweight8(cfg->channels_mask);
+		tmu->model = id->driver_data;
 	} else {
 		dev_err(&tmu->pdev->dev, "missing platform data\n");
 		return -ENXIO;