regulator: max16989: add support to read value from OTP

Add support to read parameters from device OTP if properties
are not provided from DT. This help on not changing the HW
OTP value if not required.

bug 200111792

Change-Id: I736d52025ac065d3943ed0731eb4b2472ad2f2c7
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
(cherry picked from commit b3aa7e61446b6300fe0c87b79955e876292a3987)
Reviewed-on: http://git-master/r/754585

diff --git a/drivers/regulator/max16989-regulator.c b/drivers/regulator/max16989-regulator.c
index ea51f084fc1807dccff5eb29ce50d131c77909a6..a034643990a5c9a69a680810b2437ec0b2133454 100644 (file)
--- a/drivers/regulator/max16989-regulator.c
+++ b/drivers/regulator/max16989-regulator.c
@@ -46,7 +46,7 @@
 #define MAX16989_CONFIG_VSTEP                  BIT(7)
 #define MAX16989_CONFIG_FPWM                   BIT(3)
 #define MAX16989_CONFIG_SS                     BIT(2)
-#define MAX16989_CONFIG_SYNC_OUTPUT            0x00
+#define MAX16989_CONFIG_SYNC_OUTPUT            0x02
 
 #define MAX16989_TCONFIG_ENTRK                 BIT(7)
 
@@ -139,6 +139,10 @@ static struct regulator_ops max16989_ops = {
        .get_mode               = max16989_get_mode,
        .set_voltage_time_sel   = max16989_set_voltage_time_sel,
 };
+static int slew_table_startup[] = {
+       22000, 11000, 5500, 11000, 5500, 22000, 22000, 11000, 5500, 5500};
+static int slew_table_rising[] = {
+       22000, 22000, 22000, 11000, 11000, 22000, 22000, 22000, 22000, 5500};
 
 static int max16989_init(struct max16989_chip *mchip,
        struct max16989_regulator_platform_data *pdata)
@@ -152,6 +156,21 @@ static int max16989_init(struct max16989_chip *mchip,
        int vsel;
 
        config = 0;
+       if (pdata->voltage_step_uv == -EINVAL) {
+               ret = regmap_read(mchip->rmap, MAX16989_CONFIG_REG, &config);
+               if (ret < 0) {
+                       dev_err(mchip->dev, "CONFIG reg read failed: %d\n", ret);
+                       return ret;
+               }
+               pdata->voltage_step_uv = (config & MAX16989_CONFIG_VSTEP) ?
+                                               12500 : 10000;
+
+               pdata->enable_clock_ss = !!(config & MAX16989_CONFIG_SS);
+               pdata->enable_sync_output = ((config & 0x3) ==
+                                               MAX16989_CONFIG_SYNC_OUTPUT);
+               config = 0;
+       }
+
        if (pdata->voltage_step_uv == 12500)
                config |= MAX16989_CONFIG_VSTEP;
        if (pdata->enable_clock_ss)
@@ -234,6 +253,21 @@ static int max16989_init(struct max16989_chip *mchip,
                return ret;
        }
 
+       if (pdata->slew_rate == -EINVAL) {
+               slew = 0;
+               ret = regmap_read(mchip->rmap, MAX16989_SLEW_REG, &slew);
+               if (ret < 0) {
+                       dev_err(mchip->dev, "SLEW reg read failed: %d\n", ret);
+                       return ret;
+               }
+
+               slew = slew & 0xF;
+               if (slew > 0x9)
+                       slew = 0x9;
+               startup = slew_table_startup[slew];
+               rising = slew_table_rising[slew];
+               goto slew_done;
+       }
        startup = 22000;
        rising = 22000;
        slew = 0;
@@ -276,6 +310,7 @@ static int max16989_init(struct max16989_chip *mchip,
                dev_err(mchip->dev, "SLEW write failed: %d\n", ret);
                return ret;
        }
+slew_done:
        if (pdata->voltage_step_uv == 12500) {
                rising = DIV_ROUND_UP(rising * 5, 4);
                startup = DIV_ROUND_UP(startup * 5, 4);
@@ -403,7 +438,7 @@ static struct max16989_regulator_platform_data *
        }
 
        ret = of_property_read_u32(np, "regulator-voltage-steps", &pval);
-       pdata->voltage_step_uv = (ret) ? 12500 : pval;
+       pdata->voltage_step_uv = (ret) ? -EINVAL : pval;
 
        pdata->enable_sync_output = of_property_read_bool(np,
                                "maxim,enable-sync-output");
@@ -426,7 +461,7 @@ static struct max16989_regulator_platform_data *
        pdata->tracking_device_i2c_address = (ret) ? 0 : pval;
 
        ret = of_property_read_u32(np, "maxim,slew-rate", &pval);
-       pdata->slew_rate = (ret) ? 0 : pval;
+       pdata->slew_rate = (ret) ? -EINVAL : pval;
        return pdata;
 }