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Date: Fri, 16 Mar 2012 14:59:08 +0100 From: Lars-Peter Clausen <lars@...afoo.de> To: Axel Lin <axel.lin@...il.com> CC: linux-kernel@...r.kernel.org, Balaji Rao <balajirrao@...nmoko.org>, Liam Girdwood <lrg@...com>, Mark Brown <broonie@...nsource.wolfsonmicro.com> Subject: Re: [PATCH RFT 1/2] regulator: pcf50633: Don't write to reserved bits of AUTO output voltage select register On 03/16/2012 02:35 PM, Axel Lin wrote: > The datasheet says 00000000 to 00101110 are reserved, and the min value of the > voltage setting is 1.8 V. > Thus don't write 0 to AUTO output voltage select register (address 1Ah). > > Table 50. AUTOOUT - AUTO output voltage select register (address 1Ah) bit description[1] > Bit Symbol Access Description > 7:0 auto_out R/W VO(prog) = 0.625 + auto_out × 0.025 V > eg. 00000000 to 00101110: reserved > 00101111: 1.8 V (min) > 01010011: 2.7 V > 01101010: 3.275 V > 01101011: 3.300 V > 01101100: 3.325 V > 01111111 : 3.800 V (max) > ..... ..... > 11111110 : 3.800 V > 11111111 : 3.800 V > > This patch also fixes a bug in pcf50633_regulator_list_voltage. > It is wrong to do "index += 0x2f" for PCF50633_REGULATOR_AUTO in > pcf50633_regulator_list_voltage. The purpose of adding 0x2f to index is because > current code return 0 in auto_voltage_bits when millivolts < 1800. > For millivolts > 1800, adding 0x2f to index is wrong. > > We should handle this by > return -EINVAL if the selector is in the reserved range of AUTOOUT. > > Signed-off-by: Axel Lin <axel.lin@...il.com> > --- > drivers/regulator/pcf50633-regulator.c | 23 +++++------------------ > 1 files changed, 5 insertions(+), 18 deletions(-) > > diff --git a/drivers/regulator/pcf50633-regulator.c b/drivers/regulator/pcf50633-regulator.c > index 6db46c6..3cefc63 100644 > --- a/drivers/regulator/pcf50633-regulator.c > +++ b/drivers/regulator/pcf50633-regulator.c > @@ -52,7 +52,7 @@ static const u8 pcf50633_regulator_registers[PCF50633_NUM_REGULATORS] = { >[...] > > @@ -161,6 +158,9 @@ static int pcf50633_regulator_voltage_value(enum pcf50633_regulator_id id, > > switch (id) { > case PCF50633_REGULATOR_AUTO: > + /* AUTOOUT: 00000000 to 00101110 are reserved */ > + if (bits < 0x2f) > + return -EINVAL; > millivolts = auto_voltage_value(bits); > break; > case PCF50633_REGULATOR_DOWN1: > @@ -208,20 +208,7 @@ static int pcf50633_regulator_get_voltage(struct regulator_dev *rdev) > static int pcf50633_regulator_list_voltage(struct regulator_dev *rdev, > unsigned int index) > { > - struct pcf50633 *pcf; > - int regulator_id; > - > - pcf = rdev_get_drvdata(rdev); > - > - regulator_id = rdev_get_id(rdev); > - > - switch (regulator_id) { > - case PCF50633_REGULATOR_AUTO: > - index += 0x2f; > - break; > - default: > - break; > - } Does this make sense? Now we return -EINVAL if index is less than 0x2f -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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