twl4030_charger: allow fine control of charger current.
[firefly-linux-kernel-4.4.55.git] / drivers / power / twl4030_charger.c
index 29984b263a35def9f80b8fd77f24372e3ff7e9a1..3b7cc631bb8a151970a2b011e053f0cddaa0e6e4 100644 (file)
 #define TWL4030_BCIMFSTS4      0x10
 #define TWL4030_BCICTL1                0x23
 #define TWL4030_BB_CFG         0x12
+#define TWL4030_BCIIREF1       0x27
+#define TWL4030_BCIIREF2       0x28
+#define TWL4030_BCIMFKEY       0x11
+#define TWL4030_BCIMFTH8       0x1d
+#define TWL4030_BCIMFTH9       0x1e
 
 #define TWL4030_BCIMFSTS1      0x01
 
@@ -95,6 +100,12 @@ struct twl4030_bci {
        int                     irq_bci;
        int                     usb_enabled;
 
+       /*
+        * ichg values in uA. If any are 'large', we set CGAIN to
+        * '1' which doubles the range for half the precision.
+        */
+       unsigned int            ichg_eoc, ichg_lo, ichg_hi, cur;
+
        unsigned long           event;
 };
 
@@ -211,6 +222,146 @@ static int ua2regval(int ua, bool cgain)
        return ret;
 }
 
+static int twl4030_charger_update_current(struct twl4030_bci *bci)
+{
+       int status;
+       unsigned reg, cur_reg;
+       u8 bcictl1, oldreg, fullreg;
+       bool cgain = false;
+       u8 boot_bci;
+
+       /* First, check thresholds and see if cgain is needed */
+       if (bci->ichg_eoc >= 200000)
+               cgain = true;
+       if (bci->ichg_lo >= 400000)
+               cgain = true;
+       if (bci->ichg_hi >= 820000)
+               cgain = true;
+       if (bci->cur > 852000)
+               cgain = true;
+
+       status = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
+       if (status < 0)
+               return status;
+       if (twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &boot_bci,
+                           TWL4030_PM_MASTER_BOOT_BCI) < 0)
+               boot_bci = 0;
+       boot_bci &= 7;
+
+       if ((!!cgain) != !!(bcictl1 & TWL4030_CGAIN))
+               /* Need to turn for charging while we change the
+                * CGAIN bit.  Leave it off while everything is
+                * updated.
+                */
+               twl4030_clear_set_boot_bci(boot_bci, 0);
+
+       /*
+        * For ichg_eoc, the hardware only supports reg values matching
+        * 100XXXX000, and requires the XXXX be stored in the high nibble
+        * of TWL4030_BCIMFTH8.
+        */
+       reg = ua2regval(bci->ichg_eoc, cgain);
+       if (reg > 0x278)
+               reg = 0x278;
+       if (reg < 0x200)
+               reg = 0x200;
+       reg = (reg >> 3) & 0xf;
+       fullreg = reg << 4;
+
+       /*
+        * For ichg_lo, reg value must match 10XXXX0000.
+        * XXXX is stored in low nibble of TWL4030_BCIMFTH8.
+        */
+       reg = ua2regval(bci->ichg_lo, cgain);
+       if (reg > 0x2F0)
+               reg = 0x2F0;
+       if (reg < 0x200)
+               reg = 0x200;
+       reg = (reg >> 4) & 0xf;
+       fullreg |= reg;
+
+       /* ichg_eoc and ichg_lo live in same register */
+       status = twl4030_bci_read(TWL4030_BCIMFTH8, &oldreg);
+       if (status < 0)
+               return status;
+       if (oldreg != fullreg) {
+               status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xF4,
+                                         TWL4030_BCIMFKEY);
+               if (status < 0)
+                       return status;
+               twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
+                                fullreg, TWL4030_BCIMFTH8);
+       }
+
+       /* ichg_hi threshold must be 1XXXX01100 (I think) */
+       reg = ua2regval(bci->ichg_hi, cgain);
+       if (reg > 0x3E0)
+               reg = 0x3E0;
+       if (reg < 0x200)
+               reg = 0x200;
+       fullreg = (reg >> 5) & 0xF;
+       fullreg <<= 4;
+       status = twl4030_bci_read(TWL4030_BCIMFTH9, &oldreg);
+       if (status < 0)
+               return status;
+       if ((oldreg & 0xF0) != fullreg) {
+               fullreg |= (oldreg & 0x0F);
+               status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xE7,
+                                         TWL4030_BCIMFKEY);
+               if (status < 0)
+                       return status;
+               twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
+                                fullreg, TWL4030_BCIMFTH9);
+       }
+
+       /*
+        * And finally, set the current.  This is stored in
+        * two registers.
+        */
+       reg = ua2regval(bci->cur, cgain);
+       /* we have only 10 bits */
+       if (reg > 0x3ff)
+               reg = 0x3ff;
+       status = twl4030_bci_read(TWL4030_BCIIREF1, &oldreg);
+       if (status < 0)
+               return status;
+       cur_reg = oldreg;
+       status = twl4030_bci_read(TWL4030_BCIIREF2, &oldreg);
+       if (status < 0)
+               return status;
+       cur_reg |= oldreg << 8;
+       if (reg != oldreg) {
+               /* disable write protection for one write access for
+                * BCIIREF */
+               status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xE7,
+                                         TWL4030_BCIMFKEY);
+               if (status < 0)
+                       return status;
+               status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
+                                         (reg & 0x100) ? 3 : 2,
+                                         TWL4030_BCIIREF2);
+               if (status < 0)
+                       return status;
+               /* disable write protection for one write access for
+                * BCIIREF */
+               status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xE7,
+                                         TWL4030_BCIMFKEY);
+               if (status < 0)
+                       return status;
+               status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
+                                         reg & 0xff,
+                                         TWL4030_BCIIREF1);
+       }
+       if ((!!cgain) != !!(bcictl1 & TWL4030_CGAIN)) {
+               /* Flip CGAIN and re-enable charging */
+               bcictl1 ^= TWL4030_CGAIN;
+               twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
+                                bcictl1, TWL4030_BCICTL1);
+               twl4030_clear_set_boot_bci(0, boot_bci);
+       }
+       return 0;
+}
+
 /*
  * Enable/Disable USB Charge functionality.
  */
@@ -219,14 +370,6 @@ static int twl4030_charger_enable_usb(struct twl4030_bci *bci, bool enable)
        int ret;
 
        if (enable && !IS_ERR_OR_NULL(bci->transceiver)) {
-               /*
-                * Until we can find out what current the device can provide,
-                * require a module param to enable USB charging.
-                */
-               if (!allow_usb) {
-                       dev_warn(bci->dev, "USB charging is disabled.\n");
-                       return -EACCES;
-               }
 
                /* Need to keep phy powered */
                if (!bci->usb_enabled) {
@@ -578,6 +721,14 @@ static int twl4030_bci_probe(struct platform_device *pdev)
        if (!pdata)
                pdata = twl4030_bci_parse_dt(&pdev->dev);
 
+       bci->ichg_eoc = 80100; /* Stop charging when current drops to here */
+       bci->ichg_lo = 241000; /* Low threshold */
+       bci->ichg_hi = 500000; /* High threshold */
+       if (allow_usb)
+               bci->cur = 500000;  /* 500mA */
+       else
+               bci->cur = 100000;  /* 100mA */
+
        bci->dev = &pdev->dev;
        bci->irq_chg = platform_get_irq(pdev, 0);
        bci->irq_bci = platform_get_irq(pdev, 1);
@@ -657,6 +808,7 @@ static int twl4030_bci_probe(struct platform_device *pdev)
        if (ret < 0)
                dev_warn(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
 
+       twl4030_charger_update_current(bci);
        twl4030_charger_enable_ac(true);
        if (!IS_ERR_OR_NULL(bci->transceiver))
                twl4030_bci_usb_ncb(&bci->usb_nb,