Re: [PATCH 03/10] thermal: exynos: remove dead code for HW_MODE calibration

Bartlomiej Zolnierkiewicz
2014-05-15T15:06:56Z

On Thursday, May 15, 2014 10:14:41 AM Eduardo Valentin wrote:
> Hello Bartlomiej

Hi,

> On Mon, May 05, 2014 at 01:15:32PM +0200, Bartlomiej Zolnierkiewicz wrote:
> > There should be no functional changes caused by this patch.
> >
>
> Please provide better explanation when removing features. For instance,
> based on the comment of commit introducing it, HW_MODE is a feature of
> 5540 samsung's SoC. Question is why now it is being removed?
>
> commit 1928457ea6337043a06ca2acd9b4d01e75810a3f
> Author: Amit Daniel Kachhap <amit.daniel@samsung.com>
> Date: Mon Jun 24 16:20:46 2013 +0530
>
> thermal: exynos: Add hardware mode thermal calibration support
>
> This patch adds support for h/w mode calibration in the TMU controller.
> Soc's like 5440 support this features. The h/w bits needed for calibration
> setting are same as that of enum calibration_type.

The commit above has added HW_MODE feature but it has never been enabled.
As such it has been a dead code for almost a year now and should be removed
from the kernel. Morevoer if somebody would like to re-introduce it for
Exynos5440 (or other SoC) she/he should explain why it is needed and why it
is better than the software calibration that is used for all SoCs currently.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

> Cheers,
>
>
> > Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> > ---
> > drivers/thermal/samsung/exynos_tmu.c | 33 +------------------------------
> > drivers/thermal/samsung/exynos_tmu.h | 13 ------------
> > drivers/thermal/samsung/exynos_tmu_data.c | 3 ---
> > drivers/thermal/samsung/exynos_tmu_data.h | 2 --
> > 4 files changed, 1 insertion(+), 50 deletions(-)
> >
> > diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
> > index 0d96a51..9f2a5ee 100644
> > --- a/drivers/thermal/samsung/exynos_tmu.c
> > +++ b/drivers/thermal/samsung/exynos_tmu.c
> > @@ -76,9 +76,6 @@ static int temp_to_code(struct exynos_tmu_data *data, u8 temp)
> > struct exynos_tmu_platform_data *pdata = data->pdata;
> > int temp_code;
> >
> > - if (pdata->cal_mode == HW_MODE)
> > - return temp;
> > -
> > if (data->soc == SOC_ARCH_EXYNOS4210)
> > /* temp should range between 25 and 125 */
> > if (temp < 25 || temp > 125) {
> > @@ -113,9 +110,6 @@ static int code_to_temp(struct exynos_tmu_data *data, u8 temp_code)
> > struct exynos_tmu_platform_data *pdata = data->pdata;
> > int temp;
> >
> > - if (pdata->cal_mode == HW_MODE)
> > - return temp_code;
> > -
> > if (data->soc == SOC_ARCH_EXYNOS4210)
> > /* temp_code should range between 75 and 175 */
> > if (temp_code < 75 || temp_code > 175) {
> > @@ -164,9 +158,6 @@ static int exynos_tmu_initialize(struct platform_device *pdev)
> > if (TMU_SUPPORTS(pdata, TRIM_RELOAD))
> > __raw_writel(1, data->base + reg->triminfo_ctrl);
> >
> > - if (pdata->cal_mode == HW_MODE)
> > - goto skip_calib_data;
> > -
> > /* Save trimming info in order to perform calibration */
> > if (data->soc == SOC_ARCH_EXYNOS5440) {
> > /*
> > @@ -202,7 +193,6 @@ static int exynos_tmu_initialize(struct platform_device *pdev)
> > (pdata->efuse_value >> reg->triminfo_85_shift) &
> > EXYNOS_TMU_TEMP_MASK;
> >
> > -skip_calib_data:
> > if (pdata->max_trigger_level > MAX_THRESHOLD_LEVS) {
> > dev_err(&pdev->dev, "Invalid max trigger level\n");
> > ret = -EINVAL;
> > @@ -311,7 +301,7 @@ static void exynos_tmu_control(struct platform_device *pdev, bool on)
> > struct exynos_tmu_data *data = platform_get_drvdata(pdev);
> > struct exynos_tmu_platform_data *pdata = data->pdata;
> > const struct exynos_tmu_registers *reg = pdata->registers;
> > - unsigned int con, interrupt_en, cal_val;
> > + unsigned int con, interrupt_en;
> >
> > mutex_lock(&data->lock);
> > clk_enable(data->clk);
> > @@ -337,27 +327,6 @@ static void exynos_tmu_control(struct platform_device *pdev, bool on)
> > con |= (pdata->noise_cancel_mode << reg->therm_trip_mode_shift);
> > }
> >
> > - if (pdata->cal_mode == HW_MODE) {
> > - con &= ~(reg->calib_mode_mask << reg->calib_mode_shift);
> > - cal_val = 0;
> > - switch (pdata->cal_type) {
> > - case TYPE_TWO_POINT_TRIMMING:
> > - cal_val = 3;
> > - break;
> > - case TYPE_ONE_POINT_TRIMMING_85:
> > - cal_val = 2;
> > - break;
> > - case TYPE_ONE_POINT_TRIMMING_25:
> > - cal_val = 1;
> > - break;
> > - case TYPE_NONE:
> > - break;
> > - default:
> > - dev_err(&pdev->dev, "Invalid calibration type, using none\n");
> > - }
> > - con |= cal_val << reg->calib_mode_shift;
> > - }
> > -
> > if (on) {
> > con |= (1 << reg->core_en_shift);
> > interrupt_en =
> > diff --git a/drivers/thermal/samsung/exynos_tmu.h b/drivers/thermal/samsung/exynos_tmu.h
> > index 80dc899..e417af8 100644
> > --- a/drivers/thermal/samsung/exynos_tmu.h
> > +++ b/drivers/thermal/samsung/exynos_tmu.h
> > @@ -34,11 +34,6 @@ enum calibration_type {
> > TYPE_NONE,
> > };
> >
> > -enum calibration_mode {
> > - SW_MODE,
> > - HW_MODE,
> > -};
> > -
> > enum soc_type {
> > SOC_ARCH_EXYNOS4210 = 1,
> > SOC_ARCH_EXYNOS4412,
> > @@ -92,10 +87,6 @@ enum soc_type {
> > * @buf_slope_sel_shift: shift bits of amplifier gain value in tmu_ctrl
> > register.
> > * @buf_slope_sel_mask: mask bits of amplifier gain value in tmu_ctrl register.
> > - * @calib_mode_shift: shift bits of calibration mode value in tmu_ctrl
> > - register.
> > - * @calib_mode_mask: mask bits of calibration mode value in tmu_ctrl
> > - register.
> > * @core_en_shift: shift bits of TMU core enable bit in tmu_ctrl register.
> > * @tmu_status: register drescribing the TMU status.
> > * @tmu_cur_temp: register containing the current temperature of the TMU.
> > @@ -139,8 +130,6 @@ struct exynos_tmu_registers {
> > u32 therm_trip_en_shift;
> > u32 buf_slope_sel_shift;
> > u32 buf_slope_sel_mask;
> > - u32 calib_mode_shift;
> > - u32 calib_mode_mask;
> > u32 core_en_shift;
> >
> > u32 tmu_status;
> > @@ -222,7 +211,6 @@ struct exynos_tmu_registers {
> > * @default_temp_offset: default temperature offset in case of no trimming
> > * @test_mux; information if SoC supports test MUX
> > * @cal_type: calibration type for temperature
> > - * @cal_mode: calibration mode for temperature
> > * @freq_clip_table: Table representing frequency reduction percentage.
> > * @freq_tab_count: Count of the above table as frequency reduction may
> > * applicable to only some of the trigger levels.
> > @@ -253,7 +241,6 @@ struct exynos_tmu_platform_data {
> > u8 test_mux;
> >
> > enum calibration_type cal_type;
> > - enum calibration_mode cal_mode;
> > enum soc_type type;
> > struct freq_clip_table freq_tab[4];
> > unsigned int freq_tab_count;
> > diff --git a/drivers/thermal/samsung/exynos_tmu_data.c b/drivers/thermal/samsung/exynos_tmu_data.c
> > index 36d64d6..4b992d9 100644
> > --- a/drivers/thermal/samsung/exynos_tmu_data.c
> > +++ b/drivers/thermal/samsung/exynos_tmu_data.c
> > @@ -205,8 +205,6 @@ static const struct exynos_tmu_registers exynos5440_tmu_registers = {
> > .therm_trip_en_shift = EXYNOS_TMU_THERM_TRIP_EN_SHIFT,
> > .buf_slope_sel_shift = EXYNOS_TMU_BUF_SLOPE_SEL_SHIFT,
> > .buf_slope_sel_mask = EXYNOS_TMU_BUF_SLOPE_SEL_MASK,
> > - .calib_mode_shift = EXYNOS_TMU_CALIB_MODE_SHIFT,
> > - .calib_mode_mask = EXYNOS_TMU_CALIB_MODE_MASK,
> > .core_en_shift = EXYNOS_TMU_CORE_EN_SHIFT,
> > .tmu_status = EXYNOS5440_TMU_S0_7_STATUS,
> > .tmu_cur_temp = EXYNOS5440_TMU_S0_7_TEMP,
> > @@ -243,7 +241,6 @@ static const struct exynos_tmu_registers exynos5440_tmu_registers = {
> > .reference_voltage = 16, \
> > .noise_cancel_mode = 4, \
> > .cal_type = TYPE_ONE_POINT_TRIMMING, \
> > - .cal_mode = 0, \
> > .efuse_value = 0x5b2d, \
> > .min_efuse_value = 16, \
> > .max_efuse_value = 76, \
> > diff --git a/drivers/thermal/samsung/exynos_tmu_data.h b/drivers/thermal/samsung/exynos_tmu_data.h
> > index d4eeddb..1fed00d 100644
> > --- a/drivers/thermal/samsung/exynos_tmu_data.h
> > +++ b/drivers/thermal/samsung/exynos_tmu_data.h
> > @@ -60,8 +60,6 @@
> > #define EXYNOS_TMU_TRIP_MODE_SHIFT 13
> > #define EXYNOS_TMU_TRIP_MODE_MASK 0x7
> > #define EXYNOS_TMU_THERM_TRIP_EN_SHIFT 12
> > -#define EXYNOS_TMU_CALIB_MODE_SHIFT 4
> > -#define EXYNOS_TMU_CALIB_MODE_MASK 0x3
> >
> > #define EXYNOS_TMU_INTEN_RISE0_SHIFT 0
> > #define EXYNOS_TMU_INTEN_RISE1_SHIFT 4