diff mbox

[v3,3/4] rtc: ds1307: factor out century bit handling

Message ID cec62c55-1a12-9804-e589-0014eb482ca1@gmail.com
State Accepted
Headers show

Commit Message

Heiner Kallweit June 5, 2017, 3:57 p.m. UTC 
The driver has lots of places with chip-specific code what doesn't
necessarily facilitate maintenance.

Let's describe chip-specific differences in century bit handling
in struct chip_desc to improve this.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
v2:
- no changes
v3:
- add Reviewed-by
---
 drivers/rtc/rtc-ds1307.c | 70 ++++++++++++++++++------------------------------
 1 file changed, 26 insertions(+), 44 deletions(-)

Comments

Alexandre Belloni July 5, 2017, 8:54 p.m. UTC | #1 
On 05/06/2017 at 17:57:33 +0200, Heiner Kallweit wrote:
> The driver has lots of places with chip-specific code what doesn't
> necessarily facilitate maintenance.
> 
> Let's describe chip-specific differences in century bit handling
> in struct chip_desc to improve this.
> 
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> v2:
> - no changes
> v3:
> - add Reviewed-by
> ---
>  drivers/rtc/rtc-ds1307.c | 70 ++++++++++++++++++------------------------------
>  1 file changed, 26 insertions(+), 44 deletions(-)
> 
Applied, thanks.
diff mbox

Patch

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index bf906e9f..79160027 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -135,6 +135,9 @@  struct chip_desc {
 	unsigned		alarm:1;
 	u16			nvram_offset;
 	u16			nvram_size;
+	u8			century_reg;
+	u8			century_enable_bit;
+	u8			century_bit;
 	u16			trickle_charger_reg;
 	u8			trickle_charger_setup;
 	u8			(*do_trickle_setup)(struct ds1307 *, uint32_t,
@@ -150,6 +153,8 @@  static struct chip_desc chips[last_ds_type] = {
 	},
 	[ds_1337] = {
 		.alarm		= 1,
+		.century_reg	= DS1307_REG_MONTH,
+		.century_bit	= DS1337_BIT_CENTURY,
 	},
 	[ds_1338] = {
 		.nvram_offset	= 8,
@@ -157,10 +162,15 @@  static struct chip_desc chips[last_ds_type] = {
 	},
 	[ds_1339] = {
 		.alarm		= 1,
+		.century_reg	= DS1307_REG_MONTH,
+		.century_bit	= DS1337_BIT_CENTURY,
 		.trickle_charger_reg = 0x10,
 		.do_trickle_setup = &do_trickle_setup_ds1339,
 	},
 	[ds_1340] = {
+		.century_reg	= DS1307_REG_HOUR,
+		.century_enable_bit = DS1340_BIT_CENTURY_EN,
+		.century_bit	= DS1340_BIT_CENTURY,
 		.trickle_charger_reg = 0x08,
 	},
 	[ds_1388] = {
@@ -168,6 +178,8 @@  static struct chip_desc chips[last_ds_type] = {
 	},
 	[ds_3231] = {
 		.alarm		= 1,
+		.century_reg	= DS1307_REG_MONTH,
+		.century_bit	= DS1337_BIT_CENTURY,
 	},
 	[mcp794xx] = {
 		.alarm		= 1,
@@ -277,6 +289,7 @@  static irqreturn_t ds1307_irq(int irq, void *dev_id)
 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
 {
 	struct ds1307	*ds1307 = dev_get_drvdata(dev);
+	const struct chip_desc *chip = &chips[ds1307->type];
 	int		tmp, ret;
 
 	/* read the RTC date and time registers all at once */
@@ -306,20 +319,8 @@  static int ds1307_get_time(struct device *dev, struct rtc_time *t)
 	t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
 
 #ifdef CONFIG_RTC_DRV_DS1307_CENTURY
-	switch (ds1307->type) {
-	case ds_1337:
-	case ds_1339:
-	case ds_3231:
-		if (ds1307->regs[DS1307_REG_MONTH] & DS1337_BIT_CENTURY)
-			t->tm_year += 100;
-		break;
-	case ds_1340:
-		if (ds1307->regs[DS1307_REG_HOUR] & DS1340_BIT_CENTURY)
-			t->tm_year += 100;
-		break;
-	default:
-		break;
-	}
+	if (ds1307->regs[chip->century_reg] & chip->century_bit)
+		t->tm_year += 100;
 #endif
 
 	dev_dbg(dev, "%s secs=%d, mins=%d, "
@@ -335,6 +336,7 @@  static int ds1307_get_time(struct device *dev, struct rtc_time *t)
 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
 {
 	struct ds1307	*ds1307 = dev_get_drvdata(dev);
+	const struct chip_desc *chip = &chips[ds1307->type];
 	int		result;
 	int		tmp;
 	u8		*buf = ds1307->regs;
@@ -345,24 +347,14 @@  static int ds1307_set_time(struct device *dev, struct rtc_time *t)
 		t->tm_hour, t->tm_mday,
 		t->tm_mon, t->tm_year, t->tm_wday);
 
-#ifdef CONFIG_RTC_DRV_DS1307_CENTURY
 	if (t->tm_year < 100)
 		return -EINVAL;
 
-	switch (ds1307->type) {
-	case ds_1337:
-	case ds_1339:
-	case ds_3231:
-	case ds_1340:
-		if (t->tm_year > 299)
-			return -EINVAL;
-	default:
-		if (t->tm_year > 199)
-			return -EINVAL;
-		break;
-	}
+#ifdef CONFIG_RTC_DRV_DS1307_CENTURY
+	if (t->tm_year > (chip->century_bit ? 299 : 199))
+		return -EINVAL;
 #else
-	if (t->tm_year < 100 || t->tm_year > 199)
+	if (t->tm_year > 199)
 		return -EINVAL;
 #endif
 
@@ -377,19 +369,12 @@  static int ds1307_set_time(struct device *dev, struct rtc_time *t)
 	tmp = t->tm_year - 100;
 	buf[DS1307_REG_YEAR] = bin2bcd(tmp);
 
-	switch (ds1307->type) {
-	case ds_1337:
-	case ds_1339:
-	case ds_3231:
-		if (t->tm_year > 199)
-			buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
-		break;
-	case ds_1340:
-		buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN;
-		if (t->tm_year > 199)
-			buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY;
-		break;
-	case mcp794xx:
+	if (chip->century_enable_bit)
+		buf[chip->century_reg] |= chip->century_enable_bit;
+	if (t->tm_year > 199 && chip->century_bit)
+		buf[chip->century_reg] |= chip->century_bit;
+
+	if (ds1307->type == mcp794xx) {
 		/*
 		 * these bits were cleared when preparing the date/time
 		 * values and need to be set again before writing the
@@ -397,9 +382,6 @@  static int ds1307_set_time(struct device *dev, struct rtc_time *t)
 		 */
 		buf[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
 		buf[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
-		break;
-	default:
-		break;
 	}
 
 	dev_dbg(dev, "%s: %7ph\n", "write", buf);