linux-kernel - [PATCH v1 1/1] gpio: dwapb: clarify usage of the register file version

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Message-Id: <20211130164956.37540-1-andriy.shevchenko@linux.intel.com>
Date:   Tue, 30 Nov 2021 18:49:56 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Hoan Tran <hoan@...amperecomputing.com>,
        Serge Semin <fancer.lancer@...il.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>
Subject: [PATCH v1 1/1] gpio: dwapb: clarify usage of the register file version

First of all, it's obvious that different versions can't be provided
simultaneously. Hence, versions can't be bit masks.

Second, due to above we have to mask out the version field in the flags
and only that can be evaluated against the certain version.

Clarify all above by:
 - introducing GPIO_REG_OFFSET_V1 and GPIO_REG_OFFSET_MASK
 - replacing conditional to mask out bits and compare to a version

Luckily there is no functional change (at least intended), so no need
to backport this.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 drivers/gpio/gpio-dwapb.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
index f98fa33e1679..ec0767d7800d 100644
--- a/drivers/gpio/gpio-dwapb.c
+++ b/drivers/gpio/gpio-dwapb.c
@@ -53,7 +53,9 @@
 #define GPIO_SWPORT_DR_STRIDE	0x0c /* register stride 3*32 bits */
 #define GPIO_SWPORT_DDR_STRIDE	0x0c /* register stride 3*32 bits */
 
+#define GPIO_REG_OFFSET_V1	0
 #define GPIO_REG_OFFSET_V2	1
+#define GPIO_REG_OFFSET_MASK	BIT(0)
 
 #define GPIO_INTMASK_V2		0x44
 #define GPIO_INTTYPE_LEVEL_V2	0x34
@@ -141,7 +143,7 @@ static inline u32 gpio_reg_v2_convert(unsigned int offset)
 
 static inline u32 gpio_reg_convert(struct dwapb_gpio *gpio, unsigned int offset)
 {
-	if (gpio->flags & GPIO_REG_OFFSET_V2)
+	if ((gpio->flags & GPIO_REG_OFFSET_MASK) == GPIO_REG_OFFSET_V2)
 		return gpio_reg_v2_convert(offset);
 
 	return offset;
@@ -668,15 +670,15 @@ static int dwapb_get_clks(struct dwapb_gpio *gpio)
 }
 
 static const struct of_device_id dwapb_of_match[] = {
-	{ .compatible = "snps,dw-apb-gpio", .data = (void *)0},
+	{ .compatible = "snps,dw-apb-gpio", .data = (void *)GPIO_REG_OFFSET_V1},
 	{ .compatible = "apm,xgene-gpio-v2", .data = (void *)GPIO_REG_OFFSET_V2},
 	{ /* Sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, dwapb_of_match);
 
 static const struct acpi_device_id dwapb_acpi_match[] = {
-	{"HISI0181", 0},
-	{"APMC0D07", 0},
+	{"HISI0181", GPIO_REG_OFFSET_V1},
+	{"APMC0D07", GPIO_REG_OFFSET_V1},
 	{"APMC0D81", GPIO_REG_OFFSET_V2},
 	{ }
 };
-- 
2.33.0