[PATCH v1 1/2] mfd: syscon: Re-use resource_size() to count max_register

[Andy Shevchenko]

Instead of open coded variant use resource_size() and replace
weird '- 3' to more understandable '- 4'.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
 drivers/mfd/syscon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index e22197c832e8..13626bb2d432 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -245,7 +245,7 @@ static int syscon_probe(struct platform_device *pdev)
 	if (!base)
 		return -ENOMEM;
 
-	syscon_config.max_register = res->end - res->start - 3;
+	syscon_config.max_register = resource_size(res) - 4;
 	if (pdata)
 		syscon_config.name = pdata->label;
 	syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
-- 
2.24.0