[PATCH] memory: jz4780_nemc: Only request IO memory the driver will use

[PATCH] memory: jz4780_nemc: Only request IO memory the driver will use

[Paul Cercueil]

The driver only uses the registers up to offset 0x54. Since the EFUSE
registers are in the middle of the NEMC registers, we only request
the registers we will use for now - that way the EFUSE driver can
probe too.

Tested-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
 drivers/memory/jz4780-nemc.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/memory/jz4780-nemc.c b/drivers/memory/jz4780-nemc.c
index b232ed279fc3..647267ea8c63 100644
--- a/drivers/memory/jz4780-nemc.c
+++ b/drivers/memory/jz4780-nemc.c
@@ -8,6 +8,7 @@
 
 #include <linux/clk.h>
 #include <linux/init.h>
+#include <linux/io.h>
 #include <linux/math64.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
@@ -288,7 +289,19 @@ static int jz4780_nemc_probe(struct platform_device *pdev)
 	nemc->dev = dev;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	nemc->base = devm_ioremap_resource(dev, res);
+
+	/*
+	 * The driver only uses the registers up to offset 0x54. Since the EFUSE
+	 * registers are in the middle of the NEMC registers, we only request
+	 * the registers we will use for now - that way the EFUSE driver can
+	 * probe too.
+	 */
+	if (!devm_request_mem_region(dev, res->start, 0x54, dev_name(dev))) {
+		dev_err(dev, "unable to request I/O memory region\n");
+		return -EBUSY;
+	}
+
+	nemc->base = devm_ioremap(dev, res->start, resource_size(res));
 	if (IS_ERR(nemc->base)) {
 		dev_err(dev, "failed to get I/O memory\n");
 		return PTR_ERR(nemc->base);
-- 
2.27.0

Re: [PATCH] memory: jz4780_nemc: Only request IO memory the driver will use

[Krzysztof Kozlowski]

On Mon, Jul 27, 2020 at 06:20:34PM +0200, Paul Cercueil wrote:
> The driver only uses the registers up to offset 0x54. Since the EFUSE
> registers are in the middle of the NEMC registers, we only request
> the registers we will use for now - that way the EFUSE driver can
> probe too.
> 
> Tested-by: H. Nikolaus Schaller <hns@goldelico.com>
> Signed-off-by: Paul Cercueil <paul@crapouillou.net>
> ---
>  drivers/memory/jz4780-nemc.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/memory/jz4780-nemc.c b/drivers/memory/jz4780-nemc.c
> index b232ed279fc3..647267ea8c63 100644
> --- a/drivers/memory/jz4780-nemc.c
> +++ b/drivers/memory/jz4780-nemc.c
> @@ -8,6 +8,7 @@
>  
>  #include <linux/clk.h>
>  #include <linux/init.h>
> +#include <linux/io.h>
>  #include <linux/math64.h>
>  #include <linux/of.h>
>  #include <linux/of_address.h>
> @@ -288,7 +289,19 @@ static int jz4780_nemc_probe(struct platform_device *pdev)
>  	nemc->dev = dev;
>  
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	nemc->base = devm_ioremap_resource(dev, res);
> +
> +	/*
> +	 * The driver only uses the registers up to offset 0x54. Since the EFUSE
> +	 * registers are in the middle of the NEMC registers, we only request
> +	 * the registers we will use for now - that way the EFUSE driver can
> +	 * probe too.
> +	 */
> +	if (!devm_request_mem_region(dev, res->start, 0x54, dev_name(dev))) {
> +		dev_err(dev, "unable to request I/O memory region\n");
> +		return -EBUSY;
> +	}
> +
> +	nemc->base = devm_ioremap(dev, res->start, resource_size(res));

Shouldn't you map only 0x54 size as well?

Best regards,
Krzysztof

Re: [PATCH] memory: jz4780_nemc: Only request IO memory the driver will use

[Paul Cercueil]

Le mar. 28 juil. 2020 à 11:21, Krzysztof Kozlowski <krzk@kernel.org> a 
écrit :
> On Mon, Jul 27, 2020 at 06:20:34PM +0200, Paul Cercueil wrote:
>>  The driver only uses the registers up to offset 0x54. Since the 
>> EFUSE
>>  registers are in the middle of the NEMC registers, we only request
>>  the registers we will use for now - that way the EFUSE driver can
>>  probe too.
>> 
>>  Tested-by: H. Nikolaus Schaller <hns@goldelico.com>
>>  Signed-off-by: Paul Cercueil <paul@crapouillou.net>
>>  ---
>>   drivers/memory/jz4780-nemc.c | 15 ++++++++++++++-
>>   1 file changed, 14 insertions(+), 1 deletion(-)
>> 
>>  diff --git a/drivers/memory/jz4780-nemc.c 
>> b/drivers/memory/jz4780-nemc.c
>>  index b232ed279fc3..647267ea8c63 100644
>>  --- a/drivers/memory/jz4780-nemc.c
>>  +++ b/drivers/memory/jz4780-nemc.c
>>  @@ -8,6 +8,7 @@
>> 
>>   #include <linux/clk.h>
>>   #include <linux/init.h>
>>  +#include <linux/io.h>
>>   #include <linux/math64.h>
>>   #include <linux/of.h>
>>   #include <linux/of_address.h>
>>  @@ -288,7 +289,19 @@ static int jz4780_nemc_probe(struct 
>> platform_device *pdev)
>>   	nemc->dev = dev;
>> 
>>   	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>  -	nemc->base = devm_ioremap_resource(dev, res);
>>  +
>>  +	/*
>>  +	 * The driver only uses the registers up to offset 0x54. Since 
>> the EFUSE
>>  +	 * registers are in the middle of the NEMC registers, we only 
>> request
>>  +	 * the registers we will use for now - that way the EFUSE driver 
>> can
>>  +	 * probe too.
>>  +	 */
>>  +	if (!devm_request_mem_region(dev, res->start, 0x54, 
>> dev_name(dev))) {
>>  +		dev_err(dev, "unable to request I/O memory region\n");
>>  +		return -EBUSY;
>>  +	}
>>  +
>>  +	nemc->base = devm_ioremap(dev, res->start, resource_size(res));
> 
> Shouldn't you map only 0x54 size as well?

I can do that.

Cheers,
-Paul