diff options
| author | Jeetesh Burman <jburman@nvidia.com> | 2015-03-24 22:55:34 +0530 |
|---|---|---|
| committer | Matthew Pedro <mapedro@nvidia.com> | 2015-05-04 13:39:04 -0700 |
| commit | 3c5f4d1060669ec73dc0ceb4e9a876a55a89c5eb (patch) | |
| tree | 935275601c06f58bbcbc75039a77e6f86230ded5 /drivers/mmc | |
| parent | f9b36d3b89f76cc48678eeb7a27cb980e89901d0 (diff) | |
mmc: tegra: Use 100000 precision instead of 1000
-To derive estimated tuning data for other than boot_mv and vmin
we are using precision of 1000.
-Use precision of 100000 to derive data more accurately
Bug 1414513
Change-Id: I9caff04515980713a83f33c4cf6b524ba022d2b8
Signed-off-by: Naveen Kumar Arepalli <naveenk@nvidia.com>
Reviewed-on: http://git-master/r/437992
(cherry picked from commit 36330ecf4ffe9333bf895f2e943f8b6b7201c012)
Signed-off-by: Jeetesh Burman <jburman@nvidia.com>
Reviewed-on: http://git-master/r/721897
GVS: Gerrit_Virtual_Submit
Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/sdhci-tegra.c | 36 |
1 files changed, 21 insertions, 15 deletions
diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c index 30a44e832155..6f2b566a1b67 100644 --- a/drivers/mmc/host/sdhci-tegra.c +++ b/drivers/mmc/host/sdhci-tegra.c @@ -228,6 +228,7 @@ #define TUNING_RETRIES 1 #define DFS_FREQ_COUNT 2 #define NEG_MAR_CHK_WIN_COUNT 2 +#define PRECISION_FOR_ESTIMATE 100000 /* Tuning core voltage requirements */ #define NOMINAL_VCORE_TUN BIT(0) #define BOOT_VCORE_TUN BIT(1) @@ -2315,19 +2316,22 @@ static int calculate_estimated_tuning_values(int speedo, } else if (voltage_mv == t2t_coeffs->vmax) { est_values->t2t_vmax = vmax_t2t; } else { - vmax_t2t = 1000 / vmax_t2t; - vmin_t2t = 1000 / vmin_t2t; + vmax_t2t = PRECISION_FOR_ESTIMATE / vmax_t2t; + vmin_t2t = PRECISION_FOR_ESTIMATE / vmin_t2t; /* - * For any intermediate voltage between 0.95V and 1.25V, + * For any intermediate voltage between 0.95V and max vcore, * calculate the slope and intercept from the T2T and tap hole - * values of 0.95V and 1.25V and use them to calculate the + * values of 0.95V and max vcore and use them to calculate the * actual values. 1/T2T is a linear function of voltage. */ - slope = ((vmax_t2t - vmin_t2t) * 1000) / - (t2t_coeffs->vmax - t2t_coeffs->vmin); - inpt = (vmax_t2t * 1000 - (slope * t2t_coeffs->vmax)) / 1000; - est_values->t2t_vmax = (slope * voltage_mv) / 1000 + inpt; - est_values->t2t_vmax = (1000 / est_values->t2t_vmax); + slope = ((vmax_t2t - vmin_t2t) * PRECISION_FOR_ESTIMATE) / + (t2t_coeffs->vmax - t2t_coeffs->vmin); + inpt = (vmax_t2t * PRECISION_FOR_ESTIMATE - + (slope * t2t_coeffs->vmax)) / PRECISION_FOR_ESTIMATE; + est_values->t2t_vmax = ((slope * voltage_mv) / + PRECISION_FOR_ESTIMATE + inpt); + est_values->t2t_vmax = (PRECISION_FOR_ESTIMATE / + est_values->t2t_vmax); } /* Est_UI = (1000000/freq_MHz)/Est_T2T_Vmax */ @@ -2348,15 +2352,17 @@ static int calculate_estimated_tuning_values(int speedo, est_values->vmax_thole = vmax_thole; } else { /* - * For any intermediate voltage between 0.95V and 1.25V, + * For any intermediate voltage between 0.95V and max vcore, * calculate the slope and intercept from the t2t and tap hole - * values of 0.95V and 1.25V and use them to calculate the + * values of 0.95V and max vcore and use them to calculate the * actual values. Tap hole is a linear function of voltage. */ - slope = ((vmax_thole - vmin_thole) * 1000) / - (t2t_coeffs->vmax - t2t_coeffs->vmin); - inpt = (vmax_thole * 1000 - (slope * t2t_coeffs->vmax)) / 1000; - est_values->vmax_thole = (slope * voltage_mv) / 1000 + inpt; + slope = ((vmax_thole - vmin_thole) * PRECISION_FOR_ESTIMATE) / + (t2t_coeffs->vmax - t2t_coeffs->vmin); + inpt = (vmax_thole * PRECISION_FOR_ESTIMATE - + (slope * t2t_coeffs->vmax)) / PRECISION_FOR_ESTIMATE; + est_values->vmax_thole = (slope * voltage_mv) / + PRECISION_FOR_ESTIMATE + inpt; } est_values->vmin_thole = vmin_thole; |