rtc: ds1307: remove regs member

ds1307->regs is never used before being read or initialized locally. There
is no point in keeping a copy in memory.

Also limit the size of the read buffer to what is really used, rename buf
to regs for consistency and use sizeof() where possible.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This commit is contained in:
Alexandre Belloni 2017-09-04 22:46:02 +02:00
parent ae930c912b
commit 042fa8c7c0

View File

@ -116,7 +116,6 @@ enum ds_type {
struct ds1307 {
u8 regs[11];
struct nvmem_config nvmem_cfg;
enum ds_type type;
unsigned long flags;
@ -397,34 +396,36 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t)
struct ds1307 *ds1307 = dev_get_drvdata(dev);
int tmp, ret;
const struct chip_desc *chip = &chips[ds1307->type];
u8 regs[7];
/* read the RTC date and time registers all at once */
ret = regmap_bulk_read(ds1307->regmap, chip->offset, ds1307->regs, 7);
ret = regmap_bulk_read(ds1307->regmap, chip->offset, regs,
sizeof(regs));
if (ret) {
dev_err(dev, "%s error %d\n", "read", ret);
return ret;
}
dev_dbg(dev, "%s: %7ph\n", "read", ds1307->regs);
dev_dbg(dev, "%s: %7ph\n", "read", regs);
/* if oscillator fail bit is set, no data can be trusted */
if (ds1307->type == m41t0 &&
ds1307->regs[DS1307_REG_MIN] & M41T0_BIT_OF) {
regs[DS1307_REG_MIN] & M41T0_BIT_OF) {
dev_warn_once(dev, "oscillator failed, set time!\n");
return -EINVAL;
}
t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
t->tm_sec = bcd2bin(regs[DS1307_REG_SECS] & 0x7f);
t->tm_min = bcd2bin(regs[DS1307_REG_MIN] & 0x7f);
tmp = regs[DS1307_REG_HOUR] & 0x3f;
t->tm_hour = bcd2bin(tmp);
t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
t->tm_wday = bcd2bin(regs[DS1307_REG_WDAY] & 0x07) - 1;
t->tm_mday = bcd2bin(regs[DS1307_REG_MDAY] & 0x3f);
tmp = regs[DS1307_REG_MONTH] & 0x1f;
t->tm_mon = bcd2bin(tmp) - 1;
t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
t->tm_year = bcd2bin(regs[DS1307_REG_YEAR]) + 100;
if (ds1307->regs[chip->century_reg] & chip->century_bit &&
if (regs[chip->century_reg] & chip->century_bit &&
IS_ENABLED(CONFIG_RTC_DRV_DS1307_CENTURY))
t->tm_year += 100;
@ -444,7 +445,7 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
const struct chip_desc *chip = &chips[ds1307->type];
int result;
int tmp;
u8 *buf = ds1307->regs;
u8 regs[7];
dev_dbg(dev, "%s secs=%d, mins=%d, "
"hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
@ -463,35 +464,36 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
return -EINVAL;
#endif
buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
regs[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
regs[DS1307_REG_MIN] = bin2bcd(t->tm_min);
regs[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
regs[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
regs[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
regs[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
/* assume 20YY not 19YY */
tmp = t->tm_year - 100;
buf[DS1307_REG_YEAR] = bin2bcd(tmp);
regs[DS1307_REG_YEAR] = bin2bcd(tmp);
if (chip->century_enable_bit)
buf[chip->century_reg] |= chip->century_enable_bit;
regs[chip->century_reg] |= chip->century_enable_bit;
if (t->tm_year > 199 && chip->century_bit)
buf[chip->century_reg] |= chip->century_bit;
regs[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
* buffer out to the device.
* regsfer out to the device.
*/
buf[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
buf[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
regs[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
regs[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
}
dev_dbg(dev, "%s: %7ph\n", "write", buf);
dev_dbg(dev, "%s: %7ph\n", "write", regs);
result = regmap_bulk_write(ds1307->regmap, chip->offset, buf, 7);
result = regmap_bulk_write(ds1307->regmap, chip->offset, regs,
sizeof(regs));
if (result) {
dev_err(dev, "%s error %d\n", "write", result);
return result;
@ -503,33 +505,34 @@ static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct ds1307 *ds1307 = dev_get_drvdata(dev);
int ret;
u8 regs[9];
if (!test_bit(HAS_ALARM, &ds1307->flags))
return -EINVAL;
/* read all ALARM1, ALARM2, and status registers at once */
ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS,
ds1307->regs, 9);
regs, sizeof(regs));
if (ret) {
dev_err(dev, "%s error %d\n", "alarm read", ret);
return ret;
}
dev_dbg(dev, "%s: %4ph, %3ph, %2ph\n", "alarm read",
&ds1307->regs[0], &ds1307->regs[4], &ds1307->regs[7]);
&regs[0], &regs[4], &regs[7]);
/*
* report alarm time (ALARM1); assume 24 hour and day-of-month modes,
* and that all four fields are checked matches
*/
t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
t->time.tm_sec = bcd2bin(regs[0] & 0x7f);
t->time.tm_min = bcd2bin(regs[1] & 0x7f);
t->time.tm_hour = bcd2bin(regs[2] & 0x3f);
t->time.tm_mday = bcd2bin(regs[3] & 0x3f);
/* ... and status */
t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
t->enabled = !!(regs[7] & DS1337_BIT_A1IE);
t->pending = !!(regs[8] & DS1337_BIT_A1I);
dev_dbg(dev, "%s secs=%d, mins=%d, "
"hours=%d, mday=%d, enabled=%d, pending=%d\n",
@ -543,7 +546,7 @@ static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct ds1307 *ds1307 = dev_get_drvdata(dev);
unsigned char *buf = ds1307->regs;
unsigned char regs[9];
u8 control, status;
int ret;
@ -557,33 +560,35 @@ static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
t->enabled, t->pending);
/* read current status of both alarms and the chip */
ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS, buf, 9);
ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS, regs,
sizeof(regs));
if (ret) {
dev_err(dev, "%s error %d\n", "alarm write", ret);
return ret;
}
control = ds1307->regs[7];
status = ds1307->regs[8];
control = regs[7];
status = regs[8];
dev_dbg(dev, "%s: %4ph, %3ph, %02x %02x\n", "alarm set (old status)",
&ds1307->regs[0], &ds1307->regs[4], control, status);
&regs[0], &regs[4], control, status);
/* set ALARM1, using 24 hour and day-of-month modes */
buf[0] = bin2bcd(t->time.tm_sec);
buf[1] = bin2bcd(t->time.tm_min);
buf[2] = bin2bcd(t->time.tm_hour);
buf[3] = bin2bcd(t->time.tm_mday);
regs[0] = bin2bcd(t->time.tm_sec);
regs[1] = bin2bcd(t->time.tm_min);
regs[2] = bin2bcd(t->time.tm_hour);
regs[3] = bin2bcd(t->time.tm_mday);
/* set ALARM2 to non-garbage */
buf[4] = 0;
buf[5] = 0;
buf[6] = 0;
regs[4] = 0;
regs[5] = 0;
regs[6] = 0;
/* disable alarms */
buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
regs[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
regs[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
ret = regmap_bulk_write(ds1307->regmap, DS1339_REG_ALARM1_SECS, buf, 9);
ret = regmap_bulk_write(ds1307->regmap, DS1339_REG_ALARM1_SECS, regs,
sizeof(regs));
if (ret) {
dev_err(dev, "can't set alarm time\n");
return ret;
@ -592,8 +597,8 @@ static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
/* optionally enable ALARM1 */
if (t->enabled) {
dev_dbg(dev, "alarm IRQ armed\n");
buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
regmap_write(ds1307->regmap, DS1337_REG_CONTROL, buf[7]);
regs[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
regmap_write(ds1307->regmap, DS1337_REG_CONTROL, regs[7]);
}
return 0;
@ -830,26 +835,27 @@ static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct ds1307 *ds1307 = dev_get_drvdata(dev);
u8 *regs = ds1307->regs;
u8 regs[10];
int ret;
if (!test_bit(HAS_ALARM, &ds1307->flags))
return -EINVAL;
/* Read control and alarm 0 registers. */
ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs, 10);
ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
sizeof(regs));
if (ret)
return ret;
t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
/* Report alarm 0 time assuming 24-hour and day-of-month modes. */
t->time.tm_sec = bcd2bin(ds1307->regs[3] & 0x7f);
t->time.tm_min = bcd2bin(ds1307->regs[4] & 0x7f);
t->time.tm_hour = bcd2bin(ds1307->regs[5] & 0x3f);
t->time.tm_wday = bcd2bin(ds1307->regs[6] & 0x7) - 1;
t->time.tm_mday = bcd2bin(ds1307->regs[7] & 0x3f);
t->time.tm_mon = bcd2bin(ds1307->regs[8] & 0x1f) - 1;
t->time.tm_sec = bcd2bin(regs[3] & 0x7f);
t->time.tm_min = bcd2bin(regs[4] & 0x7f);
t->time.tm_hour = bcd2bin(regs[5] & 0x3f);
t->time.tm_wday = bcd2bin(regs[6] & 0x7) - 1;
t->time.tm_mday = bcd2bin(regs[7] & 0x3f);
t->time.tm_mon = bcd2bin(regs[8] & 0x1f) - 1;
t->time.tm_year = -1;
t->time.tm_yday = -1;
t->time.tm_isdst = -1;
@ -858,9 +864,9 @@ static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
"enabled=%d polarity=%d irq=%d match=%d\n", __func__,
t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
!!(ds1307->regs[6] & MCP794XX_BIT_ALMX_POL),
!!(ds1307->regs[6] & MCP794XX_BIT_ALMX_IF),
(ds1307->regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
!!(regs[6] & MCP794XX_BIT_ALMX_POL),
!!(regs[6] & MCP794XX_BIT_ALMX_IF),
(regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
return 0;
}
@ -868,7 +874,7 @@ static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct ds1307 *ds1307 = dev_get_drvdata(dev);
unsigned char *regs = ds1307->regs;
unsigned char regs[10];
int ret;
if (!test_bit(HAS_ALARM, &ds1307->flags))
@ -881,7 +887,8 @@ static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
t->enabled, t->pending);
/* Read control and alarm 0 registers. */
ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs, 10);
ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
sizeof(regs));
if (ret)
return ret;
@ -900,7 +907,8 @@ static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
/* Disable interrupt. We will not enable until completely programmed */
regs[0] &= ~MCP794XX_BIT_ALM0_EN;
ret = regmap_bulk_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs, 10);
ret = regmap_bulk_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
sizeof(regs));
if (ret)
return ret;
@ -1344,7 +1352,7 @@ static int ds1307_probe(struct i2c_client *client,
const struct chip_desc *chip;
bool want_irq;
bool ds1307_can_wakeup_device = false;
unsigned char *buf;
unsigned char regs[8];
struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
struct rtc_time tm;
unsigned long timestamp;
@ -1400,8 +1408,6 @@ static int ds1307_probe(struct i2c_client *client,
trickle_charger_setup);
}
buf = ds1307->regs;
#ifdef CONFIG_OF
/*
* For devices with no IRQ directly connected to the SoC, the RTC chip
@ -1423,15 +1429,15 @@ static int ds1307_probe(struct i2c_client *client,
case ds_3231:
/* get registers that the "rtc" read below won't read... */
err = regmap_bulk_read(ds1307->regmap, DS1337_REG_CONTROL,
buf, 2);
regs, 2);
if (err) {
dev_dbg(ds1307->dev, "read error %d\n", err);
goto exit;
}
/* oscillator off? turn it on, so clock can tick. */
if (ds1307->regs[0] & DS1337_BIT_nEOSC)
ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
if (regs[0] & DS1337_BIT_nEOSC)
regs[0] &= ~DS1337_BIT_nEOSC;
/*
* Using IRQ or defined as wakeup-source?
@ -1440,77 +1446,77 @@ static int ds1307_probe(struct i2c_client *client,
* running on Vbackup (BBSQI/BBSQW)
*/
if (want_irq || ds1307_can_wakeup_device) {
ds1307->regs[0] |= DS1337_BIT_INTCN | chip->bbsqi_bit;
ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
regs[0] |= DS1337_BIT_INTCN | chip->bbsqi_bit;
regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
}
regmap_write(ds1307->regmap, DS1337_REG_CONTROL,
ds1307->regs[0]);
regs[0]);
/* oscillator fault? clear flag, and warn */
if (ds1307->regs[1] & DS1337_BIT_OSF) {
if (regs[1] & DS1337_BIT_OSF) {
regmap_write(ds1307->regmap, DS1337_REG_STATUS,
ds1307->regs[1] & ~DS1337_BIT_OSF);
regs[1] & ~DS1337_BIT_OSF);
dev_warn(ds1307->dev, "SET TIME!\n");
}
break;
case rx_8025:
err = regmap_bulk_read(ds1307->regmap,
RX8025_REG_CTRL1 << 4 | 0x08, buf, 2);
RX8025_REG_CTRL1 << 4 | 0x08, regs, 2);
if (err) {
dev_dbg(ds1307->dev, "read error %d\n", err);
goto exit;
}
/* oscillator off? turn it on, so clock can tick. */
if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
ds1307->regs[1] |= RX8025_BIT_XST;
if (!(regs[1] & RX8025_BIT_XST)) {
regs[1] |= RX8025_BIT_XST;
regmap_write(ds1307->regmap,
RX8025_REG_CTRL2 << 4 | 0x08,
ds1307->regs[1]);
regs[1]);
dev_warn(ds1307->dev,
"oscillator stop detected - SET TIME!\n");
}
if (ds1307->regs[1] & RX8025_BIT_PON) {
ds1307->regs[1] &= ~RX8025_BIT_PON;
if (regs[1] & RX8025_BIT_PON) {
regs[1] &= ~RX8025_BIT_PON;
regmap_write(ds1307->regmap,
RX8025_REG_CTRL2 << 4 | 0x08,
ds1307->regs[1]);
regs[1]);
dev_warn(ds1307->dev, "power-on detected\n");
}
if (ds1307->regs[1] & RX8025_BIT_VDET) {
ds1307->regs[1] &= ~RX8025_BIT_VDET;
if (regs[1] & RX8025_BIT_VDET) {
regs[1] &= ~RX8025_BIT_VDET;
regmap_write(ds1307->regmap,
RX8025_REG_CTRL2 << 4 | 0x08,
ds1307->regs[1]);
regs[1]);
dev_warn(ds1307->dev, "voltage drop detected\n");
}
/* make sure we are running in 24hour mode */
if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
if (!(regs[0] & RX8025_BIT_2412)) {
u8 hour;
/* switch to 24 hour mode */
regmap_write(ds1307->regmap,
RX8025_REG_CTRL1 << 4 | 0x08,
ds1307->regs[0] | RX8025_BIT_2412);
regs[0] | RX8025_BIT_2412);
err = regmap_bulk_read(ds1307->regmap,
RX8025_REG_CTRL1 << 4 | 0x08,
buf, 2);
regs, 2);
if (err) {
dev_dbg(ds1307->dev, "read error %d\n", err);
goto exit;
}
/* correct hour */
hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
hour = bcd2bin(regs[DS1307_REG_HOUR]);
if (hour == 12)
hour = 0;
if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
hour += 12;
regmap_write(ds1307->regmap,
@ -1523,7 +1529,8 @@ static int ds1307_probe(struct i2c_client *client,
read_rtc:
/* read RTC registers */
err = regmap_bulk_read(ds1307->regmap, chip->offset, buf, 8);
err = regmap_bulk_read(ds1307->regmap, chip->offset, regs,
sizeof(regs));
if (err) {
dev_dbg(ds1307->dev, "read error %d\n", err);
goto exit;
@ -1534,7 +1541,7 @@ static int ds1307_probe(struct i2c_client *client,
* specify the extra bits as must-be-zero, but there are
* still a few values that are clearly out-of-range.
*/
tmp = ds1307->regs[DS1307_REG_SECS];
tmp = regs[DS1307_REG_SECS];
switch (ds1307->type) {
case ds_1307:
case m41t0:
@ -1553,9 +1560,9 @@ static int ds1307_probe(struct i2c_client *client,
regmap_write(ds1307->regmap, DS1307_REG_SECS, 0);
/* oscillator fault? clear flag, and warn */
if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
if (regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
regmap_write(ds1307->regmap, DS1307_REG_CONTROL,
ds1307->regs[DS1307_REG_CONTROL] &
regs[DS1307_REG_CONTROL] &
~DS1338_BIT_OSF);
dev_warn(ds1307->dev, "SET TIME!\n");
goto read_rtc;
@ -1580,9 +1587,9 @@ static int ds1307_probe(struct i2c_client *client,
break;
case mcp794xx:
/* make sure that the backup battery is enabled */
if (!(ds1307->regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
if (!(regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
regmap_write(ds1307->regmap, DS1307_REG_WDAY,
ds1307->regs[DS1307_REG_WDAY] |
regs[DS1307_REG_WDAY] |
MCP794XX_BIT_VBATEN);
}
@ -1599,7 +1606,7 @@ static int ds1307_probe(struct i2c_client *client,
break;
}
tmp = ds1307->regs[DS1307_REG_HOUR];
tmp = regs[DS1307_REG_HOUR];
switch (ds1307->type) {
case ds_1340:
case m41t0:
@ -1622,7 +1629,7 @@ static int ds1307_probe(struct i2c_client *client,
tmp = bcd2bin(tmp & 0x1f);
if (tmp == 12)
tmp = 0;
if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
tmp += 12;
regmap_write(ds1307->regmap, chip->offset + DS1307_REG_HOUR,
bin2bcd(tmp));