BCI: fix current calculation and CGAIN bit set procedure

Use TI formula for current calculation and a bit cleaner
way to set CGAIN bit.

diff --git a/drivers/power/twl4030_bci_battery.c b/drivers/power/twl4030_bci_battery.c
index 65b045e..8fc8711 100644 (file)
--- a/drivers/power/twl4030_bci_battery.c
+++ b/drivers/power/twl4030_bci_battery.c
@@ -153,10 +153,6 @@
 #define VOLT_STEP_SIZE         588
 #define VOLT_PSR_R             100
 
-#define CURR_STEP_SIZE         147
-#define CURR_PSR_R1            44
-#define CURR_PSR_R2            80
-
 #define BK_VOLT_STEP_SIZE      441
 #define BK_VOLT_PSR_R          100
 
@@ -616,10 +612,14 @@ static int twl4030battery_current(void)
        if (ret)
                return ret;
 
-       if (val & CGAIN) /* slope of 0.44 mV/mA */
-               return (curr * CURR_STEP_SIZE) / CURR_PSR_R1;
-       else /* slope of 0.88 mV/mA */
-               return (curr * CURR_STEP_SIZE) / CURR_PSR_R2;
+       if (val & CGAIN)
+               //ret = (int)((float)curr * 1.6617790811339199f * 2.0f - 1.7f);
+               ret = curr * 16618 * 2 - 1700 * 10000;
+       else
+               //ret = (int)((float)curr * 1.6617790811339199f - 0.85f);
+               ret = curr * 16618 - 850 * 10000;
+       ret /= 10000;
+       return ret;
 }
 
 /*
@@ -903,12 +903,23 @@ static ssize_t
 set_charge_current(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 {
        unsigned long newCurrent;
-       int ret;
+       u8 tmp, boot_bci_prev;
+       int i, ret;
 
        ret = strict_strtoul(buf, 10, &newCurrent);
        if (ret)
                return -EINVAL;
 
+       ret = twl4030_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &boot_bci_prev, REG_BOOT_BCI);
+       if (ret)
+               return ret;
+
+       /* Leave automatic mode as some things cannot be changed there. */
+       ret = clear_n_set(TWL4030_MODULE_PM_MASTER, BCIAUTOAC | BCIAUTOUSB | CVENAC,
+                       (CONFIG_DONE | BCIAUTOWEN), REG_BOOT_BCI);
+       if (ret)
+               return ret;
+
        ret = twl4030_i2c_write_u8(TWL4030_MODULE_MAIN_CHARGE, KEY_IIREF, REG_BCIMFKEY);
        if (ret)
                return ret;
@@ -925,38 +936,37 @@ set_charge_current(struct device *dev, struct device_attribute *attr, const char
        if (ret)
                return ret;
 
-       /* Set software-controlled charge */
-       twl4030charger_ac_en(ENABLE, 0);
-
        /* Set CGAIN = 0 or 1 */
-       if(newCurrent > 511) {
-               u8 tmp;
-
+       if (newCurrent > 511) {
                /* Set CGAIN = 1 -- need to wait until automatic charge turns off */
-               while(!ret) {
+               for (i = 0; i < 10; i++) {
                        clear_n_set(TWL4030_MODULE_MAIN_CHARGE, 0, CGAIN | 0x1B, REG_BCICTL1);
                        twl4030_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE, &tmp, REG_BCICTL1);
 
                        ret = tmp & CGAIN;
-                       if(!ret)
-                               mdelay(50);
+                       if (ret)
+                               break;
+                       mdelay(50);
                }
        } else {
-               u8 tmp;
-
                /* Set CGAIN = 0 -- need to wait until automatic charge turns off */
-               while(!ret) {
+               for (i = 0; i < 10; i++) {
                        clear_n_set(TWL4030_MODULE_MAIN_CHARGE, CGAIN, 0x1B, REG_BCICTL1);
                        twl4030_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE, &tmp, REG_BCICTL1);
 
                        ret = !(tmp & CGAIN);
-                       if(!ret)
-                               mdelay(50);
+                       if (ret)
+                               break;
+                       mdelay(50);
                }
        }
 
-       /* Set automatic charge (CGAIN = 0/1 persists) */
-       twl4030charger_ac_en(ENABLE, 1);
+       if (!ret)
+               dev_err(dev, "CGAIN change failed\n");
+
+       ret = twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, boot_bci_prev, REG_BOOT_BCI);
+       if (ret)
+               return ret;
 
        return count;
 }