| Message ID | 1481406644-1614-2-git-send-email-vesa.jaaskelainen@vaisala.com |
|---|---|
| State | Changes Requested |
| Headers | show |
On Sat, 10 Dec 2016, Vesa Jääskeläinen wrote: > Texas Instrument's TPS65910 has support for compensating RTC crystal > inaccuracies. When enabled every hour RTC counter value will be compensated > with two's complement value. > > Signed-off-by: Vesa Jääskeläinen <vesa.jaaskelainen@vaisala.com> > --- > drivers/rtc/rtc-tps65910.c | 132 +++++++++++++++++++++++++++++++++++++++++++ > include/linux/mfd/tps65910.h | 1 + For the MFD change: Acked-by: Lee Jones <lee.jones@linaro.org> > 2 files changed, 133 insertions(+) > > diff --git a/drivers/rtc/rtc-tps65910.c b/drivers/rtc/rtc-tps65910.c > index 5a3d53c..aafa716 100644 > --- a/drivers/rtc/rtc-tps65910.c > +++ b/drivers/rtc/rtc-tps65910.c > @@ -21,6 +21,7 @@ > #include <linux/types.h> > #include <linux/rtc.h> > #include <linux/bcd.h> > +#include <linux/math64.h> > #include <linux/platform_device.h> > #include <linux/interrupt.h> > #include <linux/mfd/tps65910.h> > @@ -33,6 +34,19 @@ struct tps65910_rtc { > /* Total number of RTC registers needed to set time*/ > #define NUM_TIME_REGS (TPS65910_YEARS - TPS65910_SECONDS + 1) > > +/* Total number of RTC registers needed to set compensation registers */ > +#define NUM_COMP_REGS (TPS65910_RTC_COMP_MSB - TPS65910_RTC_COMP_LSB + 1) > + > +/* Min and max values supported with 'offset' interface (swapped sign) */ > +#define MIN_OFFSET (-277761) > +#define MAX_OFFSET (277778) > + > +/* Number of ticks per hour */ > +#define TICKS_PER_HOUR (32768 * 3600) > + > +/* Multiplier for ppb conversions */ > +#define PPB_MULT (1000000000LL) > + > static int tps65910_rtc_alarm_irq_enable(struct device *dev, unsigned enabled) > { > struct tps65910 *tps = dev_get_drvdata(dev->parent); > @@ -187,6 +201,122 @@ static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) > return ret; > } > > +static int tps65910_rtc_set_calibration(struct device *dev, int calibration) > +{ > + unsigned char comp_data[NUM_COMP_REGS]; > + struct tps65910 *tps = dev_get_drvdata(dev->parent); > + s16 value; > + int ret; > + > + /* > + * TPS65910 uses two's complement 16 bit value for compensation for RTC > + * crystal inaccuracies. One time every hour when seconds counter > + * increments from 0 to 1 compensation value will be added to internal > + * RTC counter value. > + * > + * Compensation value 0x7FFF is prohibited value. > + * > + * Valid range for compensation value: [-32768 .. 32766] > + */ > + if ((calibration < -32768) || (calibration > 32766)) { > + dev_err(dev, "RTC calibration value out of range: %d\n", > + calibration); > + return -EINVAL; > + } > + > + value = (s16)calibration; > + > + comp_data[0] = (u16)value & 0xFF; > + comp_data[1] = ((u16)value >> 8) & 0xFF; > + > + /* Update all the compensation registers in one shot */ > + ret = regmap_bulk_write(tps->regmap, TPS65910_RTC_COMP_LSB, > + comp_data, NUM_COMP_REGS); > + if (ret < 0) { > + dev_err(dev, "rtc_set_calibration error: %d\n", ret); > + return ret; > + } > + > + /* Enable automatic compensation */ > + ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, > + TPS65910_RTC_CTRL_AUTO_COMP, TPS65910_RTC_CTRL_AUTO_COMP); > + if (ret < 0) > + dev_err(dev, "auto_comp enable failed with error: %d\n", ret); > + > + return ret; > +} > + > +static int tps65910_rtc_get_calibration(struct device *dev, int *calibration) > +{ > + unsigned char comp_data[NUM_COMP_REGS]; > + struct tps65910 *tps = dev_get_drvdata(dev->parent); > + u16 value; > + int ret; > + > + ret = regmap_bulk_read(tps->regmap, TPS65910_RTC_COMP_LSB, comp_data, > + NUM_COMP_REGS); > + if (ret < 0) { > + dev_err(dev, "rtc_get_calibration error: %d\n", ret); > + return ret; > + } > + > + value = (u16)comp_data[0] | ((u16)comp_data[1] << 8); > + > + *calibration = (s16)value; > + > + return 0; > +} > + > +static int tps65910_read_offset(struct device *dev, long *offset) > +{ > + int calibration; > + s64 tmp; > + int ret; > + > + ret = tps65910_rtc_get_calibration(dev, &calibration); > + if (ret < 0) > + return ret; > + > + /* Convert from RTC calibration register format to ppb format */ > + tmp = calibration * (s64)PPB_MULT; > + if (tmp < 0) > + tmp -= TICKS_PER_HOUR / 2LL; > + else > + tmp += TICKS_PER_HOUR / 2LL; > + tmp = div_s64(tmp, TICKS_PER_HOUR); > + > + /* Offset value operates in negative way, so swap sign */ > + *offset = (long)-tmp; > + > + return 0; > +} > + > +static int tps65910_set_offset(struct device *dev, long offset) > +{ > + int calibration; > + s64 tmp; > + int ret; > + > + /* Make sure offset value is within supported range */ > + if (offset < MIN_OFFSET || offset > MAX_OFFSET) > + return -ERANGE; > + > + /* Convert from ppb format to RTC calibration register format */ > + tmp = offset * (s64)TICKS_PER_HOUR; > + if (tmp < 0) > + tmp -= PPB_MULT / 2LL; > + else > + tmp += PPB_MULT / 2LL; > + tmp = div_s64(tmp, PPB_MULT); > + > + /* Offset value operates in negative way, so swap sign */ > + calibration = (int)-tmp; > + > + ret = tps65910_rtc_set_calibration(dev, calibration); > + > + return ret; > +} > + > static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc) > { > struct device *dev = rtc; > @@ -219,6 +349,8 @@ static const struct rtc_class_ops tps65910_rtc_ops = { > .read_alarm = tps65910_rtc_read_alarm, > .set_alarm = tps65910_rtc_set_alarm, > .alarm_irq_enable = tps65910_rtc_alarm_irq_enable, > + .read_offset = tps65910_read_offset, > + .set_offset = tps65910_set_offset, > }; > > static int tps65910_rtc_probe(struct platform_device *pdev) > diff --git a/include/linux/mfd/tps65910.h b/include/linux/mfd/tps65910.h > index 6483a6f..ffb21e7 100644 > --- a/include/linux/mfd/tps65910.h > +++ b/include/linux/mfd/tps65910.h > @@ -134,6 +134,7 @@ > > /* RTC_CTRL_REG bitfields */ > #define TPS65910_RTC_CTRL_STOP_RTC 0x01 /*0=stop, 1=run */ > +#define TPS65910_RTC_CTRL_AUTO_COMP 0x04 > #define TPS65910_RTC_CTRL_GET_TIME 0x40 > > /* RTC_STATUS_REG bitfields */
On 2016-12-12 09:44, Lee Jones wrote: > On Sat, 10 Dec 2016, Vesa Jääskeläinen wrote: > >> Texas Instrument's TPS65910 has support for compensating RTC crystal >> inaccuracies. When enabled every hour RTC counter value will be compensated >> with two's complement value. >> >> Signed-off-by: Vesa Jääskeläinen <vesa.jaaskelainen@vaisala.com> >> --- >> drivers/rtc/rtc-tps65910.c | 132 +++++++++++++++++++++++++++++++++++++++++++ >> include/linux/mfd/tps65910.h | 1 + > For the MFD change: > > Acked-by: Lee Jones <lee.jones@linaro.org> Thanks for the review. Added Acked-by to v3. Thanks, Vesa Jääskeläinen
diff --git a/drivers/rtc/rtc-tps65910.c b/drivers/rtc/rtc-tps65910.c index 5a3d53c..aafa716 100644 --- a/drivers/rtc/rtc-tps65910.c +++ b/drivers/rtc/rtc-tps65910.c @@ -21,6 +21,7 @@ #include <linux/types.h> #include <linux/rtc.h> #include <linux/bcd.h> +#include <linux/math64.h> #include <linux/platform_device.h> #include <linux/interrupt.h> #include <linux/mfd/tps65910.h> @@ -33,6 +34,19 @@ struct tps65910_rtc { /* Total number of RTC registers needed to set time*/ #define NUM_TIME_REGS (TPS65910_YEARS - TPS65910_SECONDS + 1) +/* Total number of RTC registers needed to set compensation registers */ +#define NUM_COMP_REGS (TPS65910_RTC_COMP_MSB - TPS65910_RTC_COMP_LSB + 1) + +/* Min and max values supported with 'offset' interface (swapped sign) */ +#define MIN_OFFSET (-277761) +#define MAX_OFFSET (277778) + +/* Number of ticks per hour */ +#define TICKS_PER_HOUR (32768 * 3600) + +/* Multiplier for ppb conversions */ +#define PPB_MULT (1000000000LL) + static int tps65910_rtc_alarm_irq_enable(struct device *dev, unsigned enabled) { struct tps65910 *tps = dev_get_drvdata(dev->parent); @@ -187,6 +201,122 @@ static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) return ret; } +static int tps65910_rtc_set_calibration(struct device *dev, int calibration) +{ + unsigned char comp_data[NUM_COMP_REGS]; + struct tps65910 *tps = dev_get_drvdata(dev->parent); + s16 value; + int ret; + + /* + * TPS65910 uses two's complement 16 bit value for compensation for RTC + * crystal inaccuracies. One time every hour when seconds counter + * increments from 0 to 1 compensation value will be added to internal + * RTC counter value. + * + * Compensation value 0x7FFF is prohibited value. + * + * Valid range for compensation value: [-32768 .. 32766] + */ + if ((calibration < -32768) || (calibration > 32766)) { + dev_err(dev, "RTC calibration value out of range: %d\n", + calibration); + return -EINVAL; + } + + value = (s16)calibration; + + comp_data[0] = (u16)value & 0xFF; + comp_data[1] = ((u16)value >> 8) & 0xFF; + + /* Update all the compensation registers in one shot */ + ret = regmap_bulk_write(tps->regmap, TPS65910_RTC_COMP_LSB, + comp_data, NUM_COMP_REGS); + if (ret < 0) { + dev_err(dev, "rtc_set_calibration error: %d\n", ret); + return ret; + } + + /* Enable automatic compensation */ + ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, + TPS65910_RTC_CTRL_AUTO_COMP, TPS65910_RTC_CTRL_AUTO_COMP); + if (ret < 0) + dev_err(dev, "auto_comp enable failed with error: %d\n", ret); + + return ret; +} + +static int tps65910_rtc_get_calibration(struct device *dev, int *calibration) +{ + unsigned char comp_data[NUM_COMP_REGS]; + struct tps65910 *tps = dev_get_drvdata(dev->parent); + u16 value; + int ret; + + ret = regmap_bulk_read(tps->regmap, TPS65910_RTC_COMP_LSB, comp_data, + NUM_COMP_REGS); + if (ret < 0) { + dev_err(dev, "rtc_get_calibration error: %d\n", ret); + return ret; + } + + value = (u16)comp_data[0] | ((u16)comp_data[1] << 8); + + *calibration = (s16)value; + + return 0; +} + +static int tps65910_read_offset(struct device *dev, long *offset) +{ + int calibration; + s64 tmp; + int ret; + + ret = tps65910_rtc_get_calibration(dev, &calibration); + if (ret < 0) + return ret; + + /* Convert from RTC calibration register format to ppb format */ + tmp = calibration * (s64)PPB_MULT; + if (tmp < 0) + tmp -= TICKS_PER_HOUR / 2LL; + else + tmp += TICKS_PER_HOUR / 2LL; + tmp = div_s64(tmp, TICKS_PER_HOUR); + + /* Offset value operates in negative way, so swap sign */ + *offset = (long)-tmp; + + return 0; +} + +static int tps65910_set_offset(struct device *dev, long offset) +{ + int calibration; + s64 tmp; + int ret; + + /* Make sure offset value is within supported range */ + if (offset < MIN_OFFSET || offset > MAX_OFFSET) + return -ERANGE; + + /* Convert from ppb format to RTC calibration register format */ + tmp = offset * (s64)TICKS_PER_HOUR; + if (tmp < 0) + tmp -= PPB_MULT / 2LL; + else + tmp += PPB_MULT / 2LL; + tmp = div_s64(tmp, PPB_MULT); + + /* Offset value operates in negative way, so swap sign */ + calibration = (int)-tmp; + + ret = tps65910_rtc_set_calibration(dev, calibration); + + return ret; +} + static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc) { struct device *dev = rtc; @@ -219,6 +349,8 @@ static const struct rtc_class_ops tps65910_rtc_ops = { .read_alarm = tps65910_rtc_read_alarm, .set_alarm = tps65910_rtc_set_alarm, .alarm_irq_enable = tps65910_rtc_alarm_irq_enable, + .read_offset = tps65910_read_offset, + .set_offset = tps65910_set_offset, }; static int tps65910_rtc_probe(struct platform_device *pdev) diff --git a/include/linux/mfd/tps65910.h b/include/linux/mfd/tps65910.h index 6483a6f..ffb21e7 100644 --- a/include/linux/mfd/tps65910.h +++ b/include/linux/mfd/tps65910.h @@ -134,6 +134,7 @@ /* RTC_CTRL_REG bitfields */ #define TPS65910_RTC_CTRL_STOP_RTC 0x01 /*0=stop, 1=run */ +#define TPS65910_RTC_CTRL_AUTO_COMP 0x04 #define TPS65910_RTC_CTRL_GET_TIME 0x40 /* RTC_STATUS_REG bitfields */
Texas Instrument's TPS65910 has support for compensating RTC crystal inaccuracies. When enabled every hour RTC counter value will be compensated with two's complement value. Signed-off-by: Vesa Jääskeläinen <vesa.jaaskelainen@vaisala.com> --- drivers/rtc/rtc-tps65910.c | 132 +++++++++++++++++++++++++++++++++++++++++++ include/linux/mfd/tps65910.h | 1 + 2 files changed, 133 insertions(+)