* [PATCH v3 0/1] thermal: rockchip: make temperature reporting much more accurate @ 2015-01-21 17:29 ` Caesar Wang 0 siblings, 0 replies; 12+ messages in thread From: Caesar Wang @ 2015-01-21 17:29 UTC (permalink / raw) To: Heiko Stuebner, Zhang Rui, Eduardo Valentin Cc: Dmitry Torokhov, Daniel Kurtz, Caesar Wang, linux-pm, linux-kernel, linux-rockchip, linux-arm-kernel This patch is merged on chromiumos/third_party/kernel. https://chromium-review.googlesource.com/#/c/239190/ Tested on veyron boards. Changes in v3: Suggested-by Daniel Kurtz, the check doesn't reject "code == 0xfff" Fixed in rk_tsadcv2_code_to_temp(u32 code) Changes in v2: Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Caesar Wang (1): thermal: rockchip: make temperature reporting much more accurate drivers/thermal/rockchip_thermal.c | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) -- 1.9.1 ^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v3 0/1] thermal: rockchip: make temperature reporting much more accurate @ 2015-01-21 17:29 ` Caesar Wang 0 siblings, 0 replies; 12+ messages in thread From: Caesar Wang @ 2015-01-21 17:29 UTC (permalink / raw) To: linux-arm-kernel This patch is merged on chromiumos/third_party/kernel. https://chromium-review.googlesource.com/#/c/239190/ Tested on veyron boards. Changes in v3: Suggested-by Daniel Kurtz, the check doesn't reject "code == 0xfff" Fixed in rk_tsadcv2_code_to_temp(u32 code) Changes in v2: Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Caesar Wang (1): thermal: rockchip: make temperature reporting much more accurate drivers/thermal/rockchip_thermal.c | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) -- 1.9.1 ^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v3] thermal: rockchip: make temperature reporting much more accurate 2015-01-21 17:29 ` Caesar Wang @ 2015-01-21 17:29 ` Caesar Wang -1 siblings, 0 replies; 12+ messages in thread From: Caesar Wang @ 2015-01-21 17:29 UTC (permalink / raw) To: Heiko Stuebner, Zhang Rui, Eduardo Valentin Cc: Dmitry Torokhov, Daniel Kurtz, Caesar Wang, linux-arm-kernel, linux-rockchip, linux-pm, linux-kernel In general, the kernel should report temperature readings exactly as reported by the hardware. The cpu / gpu thermal driver works in 5 degree increments,but we ought to do more accurate. The temperature will do linear interpolation between the entries in the table. Test= $md5sum /dev/zero & $while true; do grep "" /sys/class/thermal/thermal_zone[1-2]/temp; sleep .5; done e.g. We can get the result as follows: /sys/class/thermal/thermal_zone1/temp:39994 /sys/class/thermal/thermal_zone2/temp:39086 /sys/class/thermal/thermal_zone1/temp:39994 /sys/class/thermal/thermal_zone2/temp:39540 /sys/class/thermal/thermal_zone1/temp:39540 /sys/class/thermal/thermal_zone2/temp:39540 /sys/class/thermal/thermal_zone1/temp:39540 /sys/class/thermal/thermal_zone2/temp:39994 Signed-off-by: Caesar Wang <wxt@rock-chips.com> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> --- Changes in v3: Suggested-by Daniel Kurtz, the check doesn't reject "code == 0xfff" Fixed in rk_tsadcv2_code_to_temp(u32 code) Changes in v2: Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> drivers/thermal/rockchip_thermal.c | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c index 1bcddfc..ce18007 100644 --- a/drivers/thermal/rockchip_thermal.c +++ b/drivers/thermal/rockchip_thermal.c @@ -193,19 +193,22 @@ static u32 rk_tsadcv2_temp_to_code(long temp) static long rk_tsadcv2_code_to_temp(u32 code) { - int high, low, mid; - - low = 0; - high = ARRAY_SIZE(v2_code_table) - 1; - mid = (high + low) / 2; + unsigned int low = 0; + unsigned int high = ARRAY_SIZE(v2_code_table) - 1; + unsigned int mid = (low + high) / 2; + unsigned int num; + unsigned long denom; + /* No code available, return callback */ if (code > v2_code_table[low].code || code < v2_code_table[high].code) - return 125000; /* No code available, return max temperature */ + return rk_tsadcv2_code_to_temp(code); while (low <= high) { - if (code >= v2_code_table[mid].code && code < - v2_code_table[mid - 1].code) - return v2_code_table[mid].temp; + if (code >= v2_code_table[mid].code && + code < v2_code_table[mid - 1].code) + break; + else if (code == TSADCV2_DATA_MASK) + break; else if (code < v2_code_table[mid].code) low = mid + 1; else @@ -213,7 +216,16 @@ static long rk_tsadcv2_code_to_temp(u32 code) mid = (low + high) / 2; } - return 125000; + /* + * The 5C granularity provided by the table is too much. Let's + * assume that the relationship between sensor readings and + * temperature between 2 table entries is linear and interpolate + * to produce less granular result. + */ + num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp; + num *= v2_code_table[mid - 1].code - code; + denom = v2_code_table[mid - 1].code - v2_code_table[mid].code; + return v2_code_table[mid - 1].temp + (num / denom); } /** -- 1.9.1 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v3] thermal: rockchip: make temperature reporting much more accurate @ 2015-01-21 17:29 ` Caesar Wang 0 siblings, 0 replies; 12+ messages in thread From: Caesar Wang @ 2015-01-21 17:29 UTC (permalink / raw) To: linux-arm-kernel In general, the kernel should report temperature readings exactly as reported by the hardware. The cpu / gpu thermal driver works in 5 degree increments,but we ought to do more accurate. The temperature will do linear interpolation between the entries in the table. Test= $md5sum /dev/zero & $while true; do grep "" /sys/class/thermal/thermal_zone[1-2]/temp; sleep .5; done e.g. We can get the result as follows: /sys/class/thermal/thermal_zone1/temp:39994 /sys/class/thermal/thermal_zone2/temp:39086 /sys/class/thermal/thermal_zone1/temp:39994 /sys/class/thermal/thermal_zone2/temp:39540 /sys/class/thermal/thermal_zone1/temp:39540 /sys/class/thermal/thermal_zone2/temp:39540 /sys/class/thermal/thermal_zone1/temp:39540 /sys/class/thermal/thermal_zone2/temp:39994 Signed-off-by: Caesar Wang <wxt@rock-chips.com> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> --- Changes in v3: Suggested-by Daniel Kurtz, the check doesn't reject "code == 0xfff" Fixed in rk_tsadcv2_code_to_temp(u32 code) Changes in v2: Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> drivers/thermal/rockchip_thermal.c | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c index 1bcddfc..ce18007 100644 --- a/drivers/thermal/rockchip_thermal.c +++ b/drivers/thermal/rockchip_thermal.c @@ -193,19 +193,22 @@ static u32 rk_tsadcv2_temp_to_code(long temp) static long rk_tsadcv2_code_to_temp(u32 code) { - int high, low, mid; - - low = 0; - high = ARRAY_SIZE(v2_code_table) - 1; - mid = (high + low) / 2; + unsigned int low = 0; + unsigned int high = ARRAY_SIZE(v2_code_table) - 1; + unsigned int mid = (low + high) / 2; + unsigned int num; + unsigned long denom; + /* No code available, return callback */ if (code > v2_code_table[low].code || code < v2_code_table[high].code) - return 125000; /* No code available, return max temperature */ + return rk_tsadcv2_code_to_temp(code); while (low <= high) { - if (code >= v2_code_table[mid].code && code < - v2_code_table[mid - 1].code) - return v2_code_table[mid].temp; + if (code >= v2_code_table[mid].code && + code < v2_code_table[mid - 1].code) + break; + else if (code == TSADCV2_DATA_MASK) + break; else if (code < v2_code_table[mid].code) low = mid + 1; else @@ -213,7 +216,16 @@ static long rk_tsadcv2_code_to_temp(u32 code) mid = (low + high) / 2; } - return 125000; + /* + * The 5C granularity provided by the table is too much. Let's + * assume that the relationship between sensor readings and + * temperature between 2 table entries is linear and interpolate + * to produce less granular result. + */ + num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp; + num *= v2_code_table[mid - 1].code - code; + denom = v2_code_table[mid - 1].code - v2_code_table[mid].code; + return v2_code_table[mid - 1].temp + (num / denom); } /** -- 1.9.1 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH v3] thermal: rockchip: make temperature reporting much more accurate 2015-01-21 17:29 ` Caesar Wang @ 2015-01-22 4:01 ` Daniel Kurtz -1 siblings, 0 replies; 12+ messages in thread From: Daniel Kurtz @ 2015-01-22 4:01 UTC (permalink / raw) To: Caesar Wang Cc: Heiko Stuebner, Zhang Rui, Eduardo Valentin, Dmitry Torokhov, linux-arm-kernel@lists.infradead.org, open list:ARM/Rockchip SoC..., linux-pm, linux-kernel@vger.kernel.org On Thu, Jan 22, 2015 at 1:29 AM, Caesar Wang <wxt@rock-chips.com> wrote: > In general, the kernel should report temperature readings exactly as > reported by the hardware. The cpu / gpu thermal driver works in 5 degree > increments,but we ought to do more accurate. The temperature will do > linear interpolation between the entries in the table. > > Test= $md5sum /dev/zero & > $while true; do grep "" /sys/class/thermal/thermal_zone[1-2]/temp; > sleep .5; done > > e.g. We can get the result as follows: > /sys/class/thermal/thermal_zone1/temp:39994 > /sys/class/thermal/thermal_zone2/temp:39086 > /sys/class/thermal/thermal_zone1/temp:39994 > /sys/class/thermal/thermal_zone2/temp:39540 > /sys/class/thermal/thermal_zone1/temp:39540 > /sys/class/thermal/thermal_zone2/temp:39540 > /sys/class/thermal/thermal_zone1/temp:39540 > /sys/class/thermal/thermal_zone2/temp:39994 > > Signed-off-by: Caesar Wang <wxt@rock-chips.com> > Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > > --- > > Changes in v3: > Suggested-by Daniel Kurtz, > the check doesn't reject "code == 0xfff" > Fixed in rk_tsadcv2_code_to_temp(u32 code) > > Changes in v2: > Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > > drivers/thermal/rockchip_thermal.c | 32 ++++++++++++++++++++++---------- > 1 file changed, 22 insertions(+), 10 deletions(-) > > diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c > index 1bcddfc..ce18007 100644 > --- a/drivers/thermal/rockchip_thermal.c > +++ b/drivers/thermal/rockchip_thermal.c > @@ -193,19 +193,22 @@ static u32 rk_tsadcv2_temp_to_code(long temp) > > static long rk_tsadcv2_code_to_temp(u32 code) > { > - int high, low, mid; > - > - low = 0; > - high = ARRAY_SIZE(v2_code_table) - 1; > - mid = (high + low) / 2; > + unsigned int low = 0; > + unsigned int high = ARRAY_SIZE(v2_code_table) - 1; > + unsigned int mid = (low + high) / 2; > + unsigned int num; > + unsigned long denom; > > + /* No code available, return callback */ > if (code > v2_code_table[low].code || code < v2_code_table[high].code) > - return 125000; /* No code available, return max temperature */ > + return rk_tsadcv2_code_to_temp(code); Isn't this an infinite recursion? > > while (low <= high) { > - if (code >= v2_code_table[mid].code && code < > - v2_code_table[mid - 1].code) > - return v2_code_table[mid].temp; > + if (code >= v2_code_table[mid].code && > + code < v2_code_table[mid - 1].code) > + break; > + else if (code == TSADCV2_DATA_MASK) > + break; > else if (code < v2_code_table[mid].code) > low = mid + 1; > else > @@ -213,7 +216,16 @@ static long rk_tsadcv2_code_to_temp(u32 code) > mid = (low + high) / 2; > } > > - return 125000; > + /* > + * The 5C granularity provided by the table is too much. Let's > + * assume that the relationship between sensor readings and > + * temperature between 2 table entries is linear and interpolate > + * to produce less granular result. > + */ > + num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp; > + num *= v2_code_table[mid - 1].code - code; > + denom = v2_code_table[mid - 1].code - v2_code_table[mid].code; > + return v2_code_table[mid - 1].temp + (num / denom); > } > > /** > -- > 1.9.1 > > ^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v3] thermal: rockchip: make temperature reporting much more accurate @ 2015-01-22 4:01 ` Daniel Kurtz 0 siblings, 0 replies; 12+ messages in thread From: Daniel Kurtz @ 2015-01-22 4:01 UTC (permalink / raw) To: linux-arm-kernel On Thu, Jan 22, 2015 at 1:29 AM, Caesar Wang <wxt@rock-chips.com> wrote: > In general, the kernel should report temperature readings exactly as > reported by the hardware. The cpu / gpu thermal driver works in 5 degree > increments,but we ought to do more accurate. The temperature will do > linear interpolation between the entries in the table. > > Test= $md5sum /dev/zero & > $while true; do grep "" /sys/class/thermal/thermal_zone[1-2]/temp; > sleep .5; done > > e.g. We can get the result as follows: > /sys/class/thermal/thermal_zone1/temp:39994 > /sys/class/thermal/thermal_zone2/temp:39086 > /sys/class/thermal/thermal_zone1/temp:39994 > /sys/class/thermal/thermal_zone2/temp:39540 > /sys/class/thermal/thermal_zone1/temp:39540 > /sys/class/thermal/thermal_zone2/temp:39540 > /sys/class/thermal/thermal_zone1/temp:39540 > /sys/class/thermal/thermal_zone2/temp:39994 > > Signed-off-by: Caesar Wang <wxt@rock-chips.com> > Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > > --- > > Changes in v3: > Suggested-by Daniel Kurtz, > the check doesn't reject "code == 0xfff" > Fixed in rk_tsadcv2_code_to_temp(u32 code) > > Changes in v2: > Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > > drivers/thermal/rockchip_thermal.c | 32 ++++++++++++++++++++++---------- > 1 file changed, 22 insertions(+), 10 deletions(-) > > diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c > index 1bcddfc..ce18007 100644 > --- a/drivers/thermal/rockchip_thermal.c > +++ b/drivers/thermal/rockchip_thermal.c > @@ -193,19 +193,22 @@ static u32 rk_tsadcv2_temp_to_code(long temp) > > static long rk_tsadcv2_code_to_temp(u32 code) > { > - int high, low, mid; > - > - low = 0; > - high = ARRAY_SIZE(v2_code_table) - 1; > - mid = (high + low) / 2; > + unsigned int low = 0; > + unsigned int high = ARRAY_SIZE(v2_code_table) - 1; > + unsigned int mid = (low + high) / 2; > + unsigned int num; > + unsigned long denom; > > + /* No code available, return callback */ > if (code > v2_code_table[low].code || code < v2_code_table[high].code) > - return 125000; /* No code available, return max temperature */ > + return rk_tsadcv2_code_to_temp(code); Isn't this an infinite recursion? > > while (low <= high) { > - if (code >= v2_code_table[mid].code && code < > - v2_code_table[mid - 1].code) > - return v2_code_table[mid].temp; > + if (code >= v2_code_table[mid].code && > + code < v2_code_table[mid - 1].code) > + break; > + else if (code == TSADCV2_DATA_MASK) > + break; > else if (code < v2_code_table[mid].code) > low = mid + 1; > else > @@ -213,7 +216,16 @@ static long rk_tsadcv2_code_to_temp(u32 code) > mid = (low + high) / 2; > } > > - return 125000; > + /* > + * The 5C granularity provided by the table is too much. Let's > + * assume that the relationship between sensor readings and > + * temperature between 2 table entries is linear and interpolate > + * to produce less granular result. > + */ > + num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp; > + num *= v2_code_table[mid - 1].code - code; > + denom = v2_code_table[mid - 1].code - v2_code_table[mid].code; > + return v2_code_table[mid - 1].temp + (num / denom); > } > > /** > -- > 1.9.1 > > ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3] thermal: rockchip: make temperature reporting much more accurate 2015-01-22 4:01 ` Daniel Kurtz @ 2015-01-22 4:21 ` Caesar Wang -1 siblings, 0 replies; 12+ messages in thread From: Caesar Wang @ 2015-01-22 4:21 UTC (permalink / raw) To: Daniel Kurtz, Caesar Wang Cc: Heiko Stuebner, Zhang Rui, Eduardo Valentin, Dmitry Torokhov, linux-arm-kernel@lists.infradead.org, open list:ARM/Rockchip SoC..., linux-pm, linux-kernel@vger.kernel.org 在 2015年01月22日 12:01, Daniel Kurtz 写道: > On Thu, Jan 22, 2015 at 1:29 AM, Caesar Wang <wxt@rock-chips.com> wrote: >> In general, the kernel should report temperature readings exactly as >> reported by the hardware. The cpu / gpu thermal driver works in 5 degree >> increments,but we ought to do more accurate. The temperature will do >> linear interpolation between the entries in the table. >> >> Test= $md5sum /dev/zero & >> $while true; do grep "" /sys/class/thermal/thermal_zone[1-2]/temp; >> sleep .5; done >> >> e.g. We can get the result as follows: >> /sys/class/thermal/thermal_zone1/temp:39994 >> /sys/class/thermal/thermal_zone2/temp:39086 >> /sys/class/thermal/thermal_zone1/temp:39994 >> /sys/class/thermal/thermal_zone2/temp:39540 >> /sys/class/thermal/thermal_zone1/temp:39540 >> /sys/class/thermal/thermal_zone2/temp:39540 >> /sys/class/thermal/thermal_zone1/temp:39540 >> /sys/class/thermal/thermal_zone2/temp:39994 >> >> Signed-off-by: Caesar Wang <wxt@rock-chips.com> >> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> >> >> --- >> >> Changes in v3: >> Suggested-by Daniel Kurtz, >> the check doesn't reject "code == 0xfff" >> Fixed in rk_tsadcv2_code_to_temp(u32 code) >> >> Changes in v2: >> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> >> >> drivers/thermal/rockchip_thermal.c | 32 ++++++++++++++++++++++---------- >> 1 file changed, 22 insertions(+), 10 deletions(-) >> >> diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c >> index 1bcddfc..ce18007 100644 >> --- a/drivers/thermal/rockchip_thermal.c >> +++ b/drivers/thermal/rockchip_thermal.c >> @@ -193,19 +193,22 @@ static u32 rk_tsadcv2_temp_to_code(long temp) >> >> static long rk_tsadcv2_code_to_temp(u32 code) >> { >> - int high, low, mid; >> - >> - low = 0; >> - high = ARRAY_SIZE(v2_code_table) - 1; >> - mid = (high + low) / 2; >> + unsigned int low = 0; >> + unsigned int high = ARRAY_SIZE(v2_code_table) - 1; >> + unsigned int mid = (low + high) / 2; >> + unsigned int num; >> + unsigned long denom; >> >> + /* No code available, return callback */ >> if (code > v2_code_table[low].code || code < v2_code_table[high].code) >> - return 125000; /* No code available, return max temperature */ >> + return rk_tsadcv2_code_to_temp(code); > Isn't this an infinite recursion? No, I think we can try check if it is happened. Maybe we can return a warning/error for it. >> while (low <= high) { >> - if (code >= v2_code_table[mid].code && code < >> - v2_code_table[mid - 1].code) >> - return v2_code_table[mid].temp; >> + if (code >= v2_code_table[mid].code && >> + code < v2_code_table[mid - 1].code) >> + break; >> + else if (code == TSADCV2_DATA_MASK) >> + break; >> else if (code < v2_code_table[mid].code) >> low = mid + 1; >> else >> @@ -213,7 +216,16 @@ static long rk_tsadcv2_code_to_temp(u32 code) >> mid = (low + high) / 2; >> } >> >> - return 125000; >> + /* >> + * The 5C granularity provided by the table is too much. Let's >> + * assume that the relationship between sensor readings and >> + * temperature between 2 table entries is linear and interpolate >> + * to produce less granular result. >> + */ >> + num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp; >> + num *= v2_code_table[mid - 1].code - code; >> + denom = v2_code_table[mid - 1].code - v2_code_table[mid].code; >> + return v2_code_table[mid - 1].temp + (num / denom); >> } >> >> /** >> -- >> 1.9.1 >> >> > > -- Best regards Caesar Wang (王晓腾) 福州瑞芯微电子有限公司 Fuzhou Rockchip Electronics Co.Ltd 福建省福州市铜盘路软件大道89号软件园A区18号楼(350003) Addr:No.18 Building, A District, No.89, software Boulevard Fuzhou, Fujian,PRC Email:wxt@rock-chips.com Tel:+86-591-83991906/07->8221 ^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v3] thermal: rockchip: make temperature reporting much more accurate @ 2015-01-22 4:21 ` Caesar Wang 0 siblings, 0 replies; 12+ messages in thread From: Caesar Wang @ 2015-01-22 4:21 UTC (permalink / raw) To: linux-arm-kernel ? 2015?01?22? 12:01, Daniel Kurtz ??: > On Thu, Jan 22, 2015 at 1:29 AM, Caesar Wang <wxt@rock-chips.com> wrote: >> In general, the kernel should report temperature readings exactly as >> reported by the hardware. The cpu / gpu thermal driver works in 5 degree >> increments,but we ought to do more accurate. The temperature will do >> linear interpolation between the entries in the table. >> >> Test= $md5sum /dev/zero & >> $while true; do grep "" /sys/class/thermal/thermal_zone[1-2]/temp; >> sleep .5; done >> >> e.g. We can get the result as follows: >> /sys/class/thermal/thermal_zone1/temp:39994 >> /sys/class/thermal/thermal_zone2/temp:39086 >> /sys/class/thermal/thermal_zone1/temp:39994 >> /sys/class/thermal/thermal_zone2/temp:39540 >> /sys/class/thermal/thermal_zone1/temp:39540 >> /sys/class/thermal/thermal_zone2/temp:39540 >> /sys/class/thermal/thermal_zone1/temp:39540 >> /sys/class/thermal/thermal_zone2/temp:39994 >> >> Signed-off-by: Caesar Wang <wxt@rock-chips.com> >> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> >> >> --- >> >> Changes in v3: >> Suggested-by Daniel Kurtz, >> the check doesn't reject "code == 0xfff" >> Fixed in rk_tsadcv2_code_to_temp(u32 code) >> >> Changes in v2: >> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> >> >> drivers/thermal/rockchip_thermal.c | 32 ++++++++++++++++++++++---------- >> 1 file changed, 22 insertions(+), 10 deletions(-) >> >> diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c >> index 1bcddfc..ce18007 100644 >> --- a/drivers/thermal/rockchip_thermal.c >> +++ b/drivers/thermal/rockchip_thermal.c >> @@ -193,19 +193,22 @@ static u32 rk_tsadcv2_temp_to_code(long temp) >> >> static long rk_tsadcv2_code_to_temp(u32 code) >> { >> - int high, low, mid; >> - >> - low = 0; >> - high = ARRAY_SIZE(v2_code_table) - 1; >> - mid = (high + low) / 2; >> + unsigned int low = 0; >> + unsigned int high = ARRAY_SIZE(v2_code_table) - 1; >> + unsigned int mid = (low + high) / 2; >> + unsigned int num; >> + unsigned long denom; >> >> + /* No code available, return callback */ >> if (code > v2_code_table[low].code || code < v2_code_table[high].code) >> - return 125000; /* No code available, return max temperature */ >> + return rk_tsadcv2_code_to_temp(code); > Isn't this an infinite recursion? No, I think we can try check if it is happened. Maybe we can return a warning/error for it. >> while (low <= high) { >> - if (code >= v2_code_table[mid].code && code < >> - v2_code_table[mid - 1].code) >> - return v2_code_table[mid].temp; >> + if (code >= v2_code_table[mid].code && >> + code < v2_code_table[mid - 1].code) >> + break; >> + else if (code == TSADCV2_DATA_MASK) >> + break; >> else if (code < v2_code_table[mid].code) >> low = mid + 1; >> else >> @@ -213,7 +216,16 @@ static long rk_tsadcv2_code_to_temp(u32 code) >> mid = (low + high) / 2; >> } >> >> - return 125000; >> + /* >> + * The 5C granularity provided by the table is too much. Let's >> + * assume that the relationship between sensor readings and >> + * temperature between 2 table entries is linear and interpolate >> + * to produce less granular result. >> + */ >> + num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp; >> + num *= v2_code_table[mid - 1].code - code; >> + denom = v2_code_table[mid - 1].code - v2_code_table[mid].code; >> + return v2_code_table[mid - 1].temp + (num / denom); >> } >> >> /** >> -- >> 1.9.1 >> >> > > -- Best regards Caesar Wang (???) ??????????? Fuzhou Rockchip Electronics Co.Ltd ?????????????89????A?18??(350003) Addr:No.18 Building, A District, No.89, software Boulevard Fuzhou, Fujian,PRC Email:wxt at rock-chips.com Tel:+86-591-83991906/07->8221 ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3] thermal: rockchip: make temperature reporting much more accurate 2015-01-22 4:21 ` Caesar Wang @ 2015-01-22 4:25 ` Daniel Kurtz -1 siblings, 0 replies; 12+ messages in thread From: Daniel Kurtz @ 2015-01-22 4:25 UTC (permalink / raw) To: Caesar Wang Cc: Caesar Wang, Heiko Stuebner, Zhang Rui, Eduardo Valentin, Dmitry Torokhov, linux-arm-kernel@lists.infradead.org, open list:ARM/Rockchip SoC..., linux-pm, linux-kernel@vger.kernel.org On Thu, Jan 22, 2015 at 12:21 PM, Caesar Wang <caesar.wang@rock-chips.com> wrote: > > 在 2015年01月22日 12:01, Daniel Kurtz 写道: > >> On Thu, Jan 22, 2015 at 1:29 AM, Caesar Wang <wxt@rock-chips.com> wrote: >>> >>> In general, the kernel should report temperature readings exactly as >>> reported by the hardware. The cpu / gpu thermal driver works in 5 degree >>> increments,but we ought to do more accurate. The temperature will do >>> linear interpolation between the entries in the table. >>> >>> Test= $md5sum /dev/zero & >>> $while true; do grep "" /sys/class/thermal/thermal_zone[1-2]/temp; >>> sleep .5; done >>> >>> e.g. We can get the result as follows: >>> /sys/class/thermal/thermal_zone1/temp:39994 >>> /sys/class/thermal/thermal_zone2/temp:39086 >>> /sys/class/thermal/thermal_zone1/temp:39994 >>> /sys/class/thermal/thermal_zone2/temp:39540 >>> /sys/class/thermal/thermal_zone1/temp:39540 >>> /sys/class/thermal/thermal_zone2/temp:39540 >>> /sys/class/thermal/thermal_zone1/temp:39540 >>> /sys/class/thermal/thermal_zone2/temp:39994 >>> >>> Signed-off-by: Caesar Wang <wxt@rock-chips.com> >>> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> >>> >>> --- >>> >>> Changes in v3: >>> Suggested-by Daniel Kurtz, >>> the check doesn't reject "code == 0xfff" >>> Fixed in rk_tsadcv2_code_to_temp(u32 code) >>> >>> Changes in v2: >>> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> >>> >>> drivers/thermal/rockchip_thermal.c | 32 >>> ++++++++++++++++++++++---------- >>> 1 file changed, 22 insertions(+), 10 deletions(-) >>> >>> diff --git a/drivers/thermal/rockchip_thermal.c >>> b/drivers/thermal/rockchip_thermal.c >>> index 1bcddfc..ce18007 100644 >>> --- a/drivers/thermal/rockchip_thermal.c >>> +++ b/drivers/thermal/rockchip_thermal.c >>> @@ -193,19 +193,22 @@ static u32 rk_tsadcv2_temp_to_code(long temp) >>> >>> static long rk_tsadcv2_code_to_temp(u32 code) >>> { >>> - int high, low, mid; >>> - >>> - low = 0; >>> - high = ARRAY_SIZE(v2_code_table) - 1; >>> - mid = (high + low) / 2; >>> + unsigned int low = 0; >>> + unsigned int high = ARRAY_SIZE(v2_code_table) - 1; >>> + unsigned int mid = (low + high) / 2; >>> + unsigned int num; >>> + unsigned long denom; >>> >>> + /* No code available, return callback */ >>> if (code > v2_code_table[low].code || code < >>> v2_code_table[high].code) >>> - return 125000; /* No code available, return max >>> temperature */ >>> + return rk_tsadcv2_code_to_temp(code); >> >> Isn't this an infinite recursion? > > > No, I think we can try check if it is happened. > Maybe we can return a warning/error for it. I mean, if the 'if' condition is true, then this will just call the same function again with the same code, and again, and again... Just return an error code here, -ENOENT maybe? I am not sure what error code is appropriate. > >>> while (low <= high) { >>> - if (code >= v2_code_table[mid].code && code < >>> - v2_code_table[mid - 1].code) >>> - return v2_code_table[mid].temp; >>> + if (code >= v2_code_table[mid].code && >>> + code < v2_code_table[mid - 1].code) >>> + break; >>> + else if (code == TSADCV2_DATA_MASK) >>> + break; >>> else if (code < v2_code_table[mid].code) >>> low = mid + 1; >>> else >>> @@ -213,7 +216,16 @@ static long rk_tsadcv2_code_to_temp(u32 code) >>> mid = (low + high) / 2; >>> } >>> >>> - return 125000; >>> + /* >>> + * The 5C granularity provided by the table is too much. Let's >>> + * assume that the relationship between sensor readings and >>> + * temperature between 2 table entries is linear and interpolate >>> + * to produce less granular result. >>> + */ >>> + num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp; >>> + num *= v2_code_table[mid - 1].code - code; >>> + denom = v2_code_table[mid - 1].code - v2_code_table[mid].code; >>> + return v2_code_table[mid - 1].temp + (num / denom); >>> } >>> >>> /** >>> -- >>> 1.9.1 >>> >>> >> >> > > -- > Best regards > Caesar Wang (王晓腾) > 福州瑞芯微电子有限公司 > Fuzhou Rockchip Electronics Co.Ltd > 福建省福州市铜盘路软件大道89号软件园A区18号楼(350003) > Addr:No.18 Building, A District, No.89, software Boulevard Fuzhou, > Fujian,PRC > Email:wxt@rock-chips.com > Tel:+86-591-83991906/07->8221 > > ^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v3] thermal: rockchip: make temperature reporting much more accurate @ 2015-01-22 4:25 ` Daniel Kurtz 0 siblings, 0 replies; 12+ messages in thread From: Daniel Kurtz @ 2015-01-22 4:25 UTC (permalink / raw) To: linux-arm-kernel On Thu, Jan 22, 2015 at 12:21 PM, Caesar Wang <caesar.wang@rock-chips.com> wrote: > > ? 2015?01?22? 12:01, Daniel Kurtz ??: > >> On Thu, Jan 22, 2015 at 1:29 AM, Caesar Wang <wxt@rock-chips.com> wrote: >>> >>> In general, the kernel should report temperature readings exactly as >>> reported by the hardware. The cpu / gpu thermal driver works in 5 degree >>> increments,but we ought to do more accurate. The temperature will do >>> linear interpolation between the entries in the table. >>> >>> Test= $md5sum /dev/zero & >>> $while true; do grep "" /sys/class/thermal/thermal_zone[1-2]/temp; >>> sleep .5; done >>> >>> e.g. We can get the result as follows: >>> /sys/class/thermal/thermal_zone1/temp:39994 >>> /sys/class/thermal/thermal_zone2/temp:39086 >>> /sys/class/thermal/thermal_zone1/temp:39994 >>> /sys/class/thermal/thermal_zone2/temp:39540 >>> /sys/class/thermal/thermal_zone1/temp:39540 >>> /sys/class/thermal/thermal_zone2/temp:39540 >>> /sys/class/thermal/thermal_zone1/temp:39540 >>> /sys/class/thermal/thermal_zone2/temp:39994 >>> >>> Signed-off-by: Caesar Wang <wxt@rock-chips.com> >>> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> >>> >>> --- >>> >>> Changes in v3: >>> Suggested-by Daniel Kurtz, >>> the check doesn't reject "code == 0xfff" >>> Fixed in rk_tsadcv2_code_to_temp(u32 code) >>> >>> Changes in v2: >>> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> >>> >>> drivers/thermal/rockchip_thermal.c | 32 >>> ++++++++++++++++++++++---------- >>> 1 file changed, 22 insertions(+), 10 deletions(-) >>> >>> diff --git a/drivers/thermal/rockchip_thermal.c >>> b/drivers/thermal/rockchip_thermal.c >>> index 1bcddfc..ce18007 100644 >>> --- a/drivers/thermal/rockchip_thermal.c >>> +++ b/drivers/thermal/rockchip_thermal.c >>> @@ -193,19 +193,22 @@ static u32 rk_tsadcv2_temp_to_code(long temp) >>> >>> static long rk_tsadcv2_code_to_temp(u32 code) >>> { >>> - int high, low, mid; >>> - >>> - low = 0; >>> - high = ARRAY_SIZE(v2_code_table) - 1; >>> - mid = (high + low) / 2; >>> + unsigned int low = 0; >>> + unsigned int high = ARRAY_SIZE(v2_code_table) - 1; >>> + unsigned int mid = (low + high) / 2; >>> + unsigned int num; >>> + unsigned long denom; >>> >>> + /* No code available, return callback */ >>> if (code > v2_code_table[low].code || code < >>> v2_code_table[high].code) >>> - return 125000; /* No code available, return max >>> temperature */ >>> + return rk_tsadcv2_code_to_temp(code); >> >> Isn't this an infinite recursion? > > > No, I think we can try check if it is happened. > Maybe we can return a warning/error for it. I mean, if the 'if' condition is true, then this will just call the same function again with the same code, and again, and again... Just return an error code here, -ENOENT maybe? I am not sure what error code is appropriate. > >>> while (low <= high) { >>> - if (code >= v2_code_table[mid].code && code < >>> - v2_code_table[mid - 1].code) >>> - return v2_code_table[mid].temp; >>> + if (code >= v2_code_table[mid].code && >>> + code < v2_code_table[mid - 1].code) >>> + break; >>> + else if (code == TSADCV2_DATA_MASK) >>> + break; >>> else if (code < v2_code_table[mid].code) >>> low = mid + 1; >>> else >>> @@ -213,7 +216,16 @@ static long rk_tsadcv2_code_to_temp(u32 code) >>> mid = (low + high) / 2; >>> } >>> >>> - return 125000; >>> + /* >>> + * The 5C granularity provided by the table is too much. Let's >>> + * assume that the relationship between sensor readings and >>> + * temperature between 2 table entries is linear and interpolate >>> + * to produce less granular result. >>> + */ >>> + num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp; >>> + num *= v2_code_table[mid - 1].code - code; >>> + denom = v2_code_table[mid - 1].code - v2_code_table[mid].code; >>> + return v2_code_table[mid - 1].temp + (num / denom); >>> } >>> >>> /** >>> -- >>> 1.9.1 >>> >>> >> >> > > -- > Best regards > Caesar Wang (???) > ??????????? > Fuzhou Rockchip Electronics Co.Ltd > ?????????????89????A?18??(350003) > Addr:No.18 Building, A District, No.89, software Boulevard Fuzhou, > Fujian,PRC > Email:wxt at rock-chips.com > Tel:+86-591-83991906/07->8221 > > ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3] thermal: rockchip: make temperature reporting much more accurate 2015-01-22 4:25 ` Daniel Kurtz @ 2015-01-22 4:57 ` Caesar Wang -1 siblings, 0 replies; 12+ messages in thread From: Caesar Wang @ 2015-01-22 4:57 UTC (permalink / raw) To: Daniel Kurtz, Caesar Wang Cc: Heiko Stuebner, linux-pm, Dmitry Torokhov, linux-kernel@vger.kernel.org, Eduardo Valentin, open list:ARM/Rockchip SoC..., Zhang Rui, linux-arm-kernel@lists.infradead.org, Caesar Wang 在 2015年01月22日 12:25, Daniel Kurtz 写道: > On Thu, Jan 22, 2015 at 12:21 PM, Caesar Wang > <caesar.wang@rock-chips.com> wrote: >> 在 2015年01月22日 12:01, Daniel Kurtz 写道: >> >>> On Thu, Jan 22, 2015 at 1:29 AM, Caesar Wang <wxt@rock-chips.com> wrote: >>>> In general, the kernel should report temperature readings exactly as >>>> reported by the hardware. The cpu / gpu thermal driver works in 5 degree >>>> increments,but we ought to do more accurate. The temperature will do >>>> linear interpolation between the entries in the table. >>>> >>>> Test= $md5sum /dev/zero & >>>> $while true; do grep "" /sys/class/thermal/thermal_zone[1-2]/temp; >>>> sleep .5; done >>>> >>>> e.g. We can get the result as follows: >>>> /sys/class/thermal/thermal_zone1/temp:39994 >>>> /sys/class/thermal/thermal_zone2/temp:39086 >>>> /sys/class/thermal/thermal_zone1/temp:39994 >>>> /sys/class/thermal/thermal_zone2/temp:39540 >>>> /sys/class/thermal/thermal_zone1/temp:39540 >>>> /sys/class/thermal/thermal_zone2/temp:39540 >>>> /sys/class/thermal/thermal_zone1/temp:39540 >>>> /sys/class/thermal/thermal_zone2/temp:39994 >>>> >>>> Signed-off-by: Caesar Wang <wxt@rock-chips.com> >>>> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> >>>> >>>> --- >>>> >>>> Changes in v3: >>>> Suggested-by Daniel Kurtz, >>>> the check doesn't reject "code == 0xfff" >>>> Fixed in rk_tsadcv2_code_to_temp(u32 code) >>>> >>>> Changes in v2: >>>> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> >>>> >>>> drivers/thermal/rockchip_thermal.c | 32 >>>> ++++++++++++++++++++++---------- >>>> 1 file changed, 22 insertions(+), 10 deletions(-) >>>> >>>> diff --git a/drivers/thermal/rockchip_thermal.c >>>> b/drivers/thermal/rockchip_thermal.c >>>> index 1bcddfc..ce18007 100644 >>>> --- a/drivers/thermal/rockchip_thermal.c >>>> +++ b/drivers/thermal/rockchip_thermal.c >>>> @@ -193,19 +193,22 @@ static u32 rk_tsadcv2_temp_to_code(long temp) >>>> >>>> static long rk_tsadcv2_code_to_temp(u32 code) >>>> { >>>> - int high, low, mid; >>>> - >>>> - low = 0; >>>> - high = ARRAY_SIZE(v2_code_table) - 1; >>>> - mid = (high + low) / 2; >>>> + unsigned int low = 0; >>>> + unsigned int high = ARRAY_SIZE(v2_code_table) - 1; >>>> + unsigned int mid = (low + high) / 2; >>>> + unsigned int num; >>>> + unsigned long denom; >>>> >>>> + /* No code available, return callback */ >>>> if (code > v2_code_table[low].code || code < >>>> v2_code_table[high].code) >>>> - return 125000; /* No code available, return max >>>> temperature */ >>>> + return rk_tsadcv2_code_to_temp(code); >>> Isn't this an infinite recursion? >> >> No, I think we can try check if it is happened. >> Maybe we can return a warning/error for it. > I mean, if the 'if' condition is true, then this will just call the > same function again with the same code, and again, and again... > Just return an error code here, -ENOENT maybe? > I am not sure what error code is appropriate. Maybe "return -EAGAIN" > >>>> while (low <= high) { >>>> - if (code >= v2_code_table[mid].code && code < >>>> - v2_code_table[mid - 1].code) >>>> - return v2_code_table[mid].temp; >>>> + if (code >= v2_code_table[mid].code && >>>> + code < v2_code_table[mid - 1].code) >>>> + break; >>>> + else if (code == TSADCV2_DATA_MASK) >>>> + break; >>>> else if (code < v2_code_table[mid].code) >>>> low = mid + 1; >>>> else >>>> @@ -213,7 +216,16 @@ static long rk_tsadcv2_code_to_temp(u32 code) >>>> mid = (low + high) / 2; >>>> } >>>> >>>> - return 125000; >>>> + /* >>>> + * The 5C granularity provided by the table is too much. Let's >>>> + * assume that the relationship between sensor readings and >>>> + * temperature between 2 table entries is linear and interpolate >>>> + * to produce less granular result. >>>> + */ >>>> + num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp; >>>> + num *= v2_code_table[mid - 1].code - code; >>>> + denom = v2_code_table[mid - 1].code - v2_code_table[mid].code; >>>> + return v2_code_table[mid - 1].temp + (num / denom); >>>> } >>>> >>>> /** >>>> -- >>>> 1.9.1 >>>> >>>> >>> >> -- >> Best regards >> Caesar Wang (王晓腾) >> 福州瑞芯微电子有限公司 >> Fuzhou Rockchip Electronics Co.Ltd >> 福建省福州市铜盘路软件大道89号软件园A区18号楼(350003) >> Addr:No.18 Building, A District, No.89, software Boulevard Fuzhou, >> Fujian,PRC >> Email:wxt@rock-chips.com >> Tel:+86-591-83991906/07->8221 >> >> > _______________________________________________ > Linux-rockchip mailing list > Linux-rockchip@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-rockchip ^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v3] thermal: rockchip: make temperature reporting much more accurate @ 2015-01-22 4:57 ` Caesar Wang 0 siblings, 0 replies; 12+ messages in thread From: Caesar Wang @ 2015-01-22 4:57 UTC (permalink / raw) To: linux-arm-kernel ? 2015?01?22? 12:25, Daniel Kurtz ??: > On Thu, Jan 22, 2015 at 12:21 PM, Caesar Wang > <caesar.wang@rock-chips.com> wrote: >> ? 2015?01?22? 12:01, Daniel Kurtz ??: >> >>> On Thu, Jan 22, 2015 at 1:29 AM, Caesar Wang <wxt@rock-chips.com> wrote: >>>> In general, the kernel should report temperature readings exactly as >>>> reported by the hardware. The cpu / gpu thermal driver works in 5 degree >>>> increments,but we ought to do more accurate. The temperature will do >>>> linear interpolation between the entries in the table. >>>> >>>> Test= $md5sum /dev/zero & >>>> $while true; do grep "" /sys/class/thermal/thermal_zone[1-2]/temp; >>>> sleep .5; done >>>> >>>> e.g. We can get the result as follows: >>>> /sys/class/thermal/thermal_zone1/temp:39994 >>>> /sys/class/thermal/thermal_zone2/temp:39086 >>>> /sys/class/thermal/thermal_zone1/temp:39994 >>>> /sys/class/thermal/thermal_zone2/temp:39540 >>>> /sys/class/thermal/thermal_zone1/temp:39540 >>>> /sys/class/thermal/thermal_zone2/temp:39540 >>>> /sys/class/thermal/thermal_zone1/temp:39540 >>>> /sys/class/thermal/thermal_zone2/temp:39994 >>>> >>>> Signed-off-by: Caesar Wang <wxt@rock-chips.com> >>>> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> >>>> >>>> --- >>>> >>>> Changes in v3: >>>> Suggested-by Daniel Kurtz, >>>> the check doesn't reject "code == 0xfff" >>>> Fixed in rk_tsadcv2_code_to_temp(u32 code) >>>> >>>> Changes in v2: >>>> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> >>>> >>>> drivers/thermal/rockchip_thermal.c | 32 >>>> ++++++++++++++++++++++---------- >>>> 1 file changed, 22 insertions(+), 10 deletions(-) >>>> >>>> diff --git a/drivers/thermal/rockchip_thermal.c >>>> b/drivers/thermal/rockchip_thermal.c >>>> index 1bcddfc..ce18007 100644 >>>> --- a/drivers/thermal/rockchip_thermal.c >>>> +++ b/drivers/thermal/rockchip_thermal.c >>>> @@ -193,19 +193,22 @@ static u32 rk_tsadcv2_temp_to_code(long temp) >>>> >>>> static long rk_tsadcv2_code_to_temp(u32 code) >>>> { >>>> - int high, low, mid; >>>> - >>>> - low = 0; >>>> - high = ARRAY_SIZE(v2_code_table) - 1; >>>> - mid = (high + low) / 2; >>>> + unsigned int low = 0; >>>> + unsigned int high = ARRAY_SIZE(v2_code_table) - 1; >>>> + unsigned int mid = (low + high) / 2; >>>> + unsigned int num; >>>> + unsigned long denom; >>>> >>>> + /* No code available, return callback */ >>>> if (code > v2_code_table[low].code || code < >>>> v2_code_table[high].code) >>>> - return 125000; /* No code available, return max >>>> temperature */ >>>> + return rk_tsadcv2_code_to_temp(code); >>> Isn't this an infinite recursion? >> >> No, I think we can try check if it is happened. >> Maybe we can return a warning/error for it. > I mean, if the 'if' condition is true, then this will just call the > same function again with the same code, and again, and again... > Just return an error code here, -ENOENT maybe? > I am not sure what error code is appropriate. Maybe "return -EAGAIN" > >>>> while (low <= high) { >>>> - if (code >= v2_code_table[mid].code && code < >>>> - v2_code_table[mid - 1].code) >>>> - return v2_code_table[mid].temp; >>>> + if (code >= v2_code_table[mid].code && >>>> + code < v2_code_table[mid - 1].code) >>>> + break; >>>> + else if (code == TSADCV2_DATA_MASK) >>>> + break; >>>> else if (code < v2_code_table[mid].code) >>>> low = mid + 1; >>>> else >>>> @@ -213,7 +216,16 @@ static long rk_tsadcv2_code_to_temp(u32 code) >>>> mid = (low + high) / 2; >>>> } >>>> >>>> - return 125000; >>>> + /* >>>> + * The 5C granularity provided by the table is too much. Let's >>>> + * assume that the relationship between sensor readings and >>>> + * temperature between 2 table entries is linear and interpolate >>>> + * to produce less granular result. >>>> + */ >>>> + num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp; >>>> + num *= v2_code_table[mid - 1].code - code; >>>> + denom = v2_code_table[mid - 1].code - v2_code_table[mid].code; >>>> + return v2_code_table[mid - 1].temp + (num / denom); >>>> } >>>> >>>> /** >>>> -- >>>> 1.9.1 >>>> >>>> >>> >> -- >> Best regards >> Caesar Wang (???) >> ??????????? >> Fuzhou Rockchip Electronics Co.Ltd >> ?????????????89????A?18??(350003) >> Addr:No.18 Building, A District, No.89, software Boulevard Fuzhou, >> Fujian,PRC >> Email:wxt at rock-chips.com >> Tel:+86-591-83991906/07->8221 >> >> > _______________________________________________ > Linux-rockchip mailing list > Linux-rockchip at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-rockchip ^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2015-01-22 4:58 UTC | newest] Thread overview: 12+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2015-01-21 17:29 [PATCH v3 0/1] thermal: rockchip: make temperature reporting much more accurate Caesar Wang 2015-01-21 17:29 ` Caesar Wang 2015-01-21 17:29 ` [PATCH v3] " Caesar Wang 2015-01-21 17:29 ` Caesar Wang 2015-01-22 4:01 ` Daniel Kurtz 2015-01-22 4:01 ` Daniel Kurtz 2015-01-22 4:21 ` Caesar Wang 2015-01-22 4:21 ` Caesar Wang 2015-01-22 4:25 ` Daniel Kurtz 2015-01-22 4:25 ` Daniel Kurtz 2015-01-22 4:57 ` Caesar Wang 2015-01-22 4:57 ` Caesar Wang
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