From 042fa8c7c04dd43b21be3ec5104681574a4f8f8c Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Mon, 4 Sep 2017 22:46:02 +0200 Subject: [PATCH] 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 --- drivers/rtc/rtc-ds1307.c | 207 ++++++++++++++++++++------------------- 1 file changed, 107 insertions(+), 100 deletions(-) diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 6038c49ed68a..8de1d7116461 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -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]); + ®s[0], ®s[4], ®s[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); + ®s[0], ®s[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));