From 7f4a633d21331155ee06c5ee44749ed35a3a3cc5 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 30 Jul 2015 10:11:24 +1000 Subject: [PATCH] twl4030_charger: add software controlled linear charging mode. Add a 'continuous' option for usb charging which enables the "linear" charging mode of the twl4030. Linear charging does a good job with not-so-reliable power sources. Auto mode does not work well as it switches off when voltage drops momentarily. Care must be taken not to over-charge. It was used with a bike hub dynamo since a year or so. In that case there are automatically charging stops when the cyclist needs a break. Original-by: Andreas Kemnade Signed-off-by: NeilBrown Signed-off-by: Sebastian Reichel --- .../ABI/testing/sysfs-class-power-twl4030 | 9 +++ drivers/power/twl4030_charger.c | 55 +++++++++++++++++-- 2 files changed, 59 insertions(+), 5 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-class-power-twl4030 b/Documentation/ABI/testing/sysfs-class-power-twl4030 index 40e0f919cbde..e8baa36aaa2b 100644 --- a/Documentation/ABI/testing/sysfs-class-power-twl4030 +++ b/Documentation/ABI/testing/sysfs-class-power-twl4030 @@ -24,3 +24,12 @@ Description: "auto" - draw power as appropriate for detected power source and battery status. "off" - do not draw any power. + "continuous" + - activate mode described as "linear" in + TWL data sheets. This uses whatever + current is available and doesn't switch off + when voltage drops. + + This is useful for unstable power sources + such as bicycle dynamo, but care should + be taken that battery is not over-charged. diff --git a/drivers/power/twl4030_charger.c b/drivers/power/twl4030_charger.c index 6fa928ed3128..de5430deaf23 100644 --- a/drivers/power/twl4030_charger.c +++ b/drivers/power/twl4030_charger.c @@ -24,6 +24,8 @@ #include #include +#define TWL4030_BCIMDEN 0x00 +#define TWL4030_BCIMDKEY 0x01 #define TWL4030_BCIMSTATEC 0x02 #define TWL4030_BCIICHG 0x08 #define TWL4030_BCIVAC 0x0a @@ -35,13 +37,16 @@ #define TWL4030_BCIIREF1 0x27 #define TWL4030_BCIIREF2 0x28 #define TWL4030_BCIMFKEY 0x11 +#define TWL4030_BCIMFEN3 0x14 #define TWL4030_BCIMFTH8 0x1d #define TWL4030_BCIMFTH9 0x1e +#define TWL4030_BCIWDKEY 0x21 #define TWL4030_BCIMFSTS1 0x01 #define TWL4030_BCIAUTOWEN BIT(5) #define TWL4030_CONFIG_DONE BIT(4) +#define TWL4030_CVENAC BIT(2) #define TWL4030_BCIAUTOUSB BIT(1) #define TWL4030_BCIAUTOAC BIT(0) #define TWL4030_CGAIN BIT(5) @@ -112,12 +117,13 @@ struct twl4030_bci { int usb_mode; /* charging mode requested */ #define CHARGE_OFF 0 #define CHARGE_AUTO 1 +#define CHARGE_LINEAR 2 unsigned long event; }; /* strings for 'usb_mode' values */ -static char *modes[] = { "off", "auto" }; +static char *modes[] = { "off", "auto", "continuous" }; /* * clear and set bits on an given register on a given module @@ -404,16 +410,42 @@ static int twl4030_charger_enable_usb(struct twl4030_bci *bci, bool enable) bci->usb_enabled = 1; } - /* forcing the field BCIAUTOUSB (BOOT_BCI[1]) to 1 */ - ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOUSB); - if (ret < 0) - return ret; + if (bci->usb_mode == CHARGE_AUTO) + /* forcing the field BCIAUTOUSB (BOOT_BCI[1]) to 1 */ + ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOUSB); /* forcing USBFASTMCHG(BCIMFSTS4[2]) to 1 */ ret = twl4030_clear_set(TWL_MODULE_MAIN_CHARGE, 0, TWL4030_USBFASTMCHG, TWL4030_BCIMFSTS4); + if (bci->usb_mode == CHARGE_LINEAR) { + twl4030_clear_set_boot_bci(TWL4030_BCIAUTOAC|TWL4030_CVENAC, 0); + /* Watch dog key: WOVF acknowledge */ + ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x33, + TWL4030_BCIWDKEY); + /* 0x24 + EKEY6: off mode */ + ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x2a, + TWL4030_BCIMDKEY); + /* EKEY2: Linear charge: USB path */ + ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x26, + TWL4030_BCIMDKEY); + /* WDKEY5: stop watchdog count */ + ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xf3, + TWL4030_BCIWDKEY); + /* enable MFEN3 access */ + ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x9c, + TWL4030_BCIMFKEY); + /* ICHGEOCEN - end-of-charge monitor (current < 80mA) + * (charging continues) + * ICHGLOWEN - current level monitor (charge continues) + * don't monitor over-current or heat save + */ + ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xf0, + TWL4030_BCIMFEN3); + } } else { ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOUSB, 0); + ret |= twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x2a, + TWL4030_BCIMDKEY); if (bci->usb_enabled) { pm_runtime_mark_last_busy(bci->transceiver->dev); pm_runtime_put_autosuspend(bci->transceiver->dev); @@ -652,6 +684,8 @@ twl4030_bci_mode_store(struct device *dev, struct device_attribute *attr, mode = 0; else if (sysfs_streq(buf, modes[1])) mode = 1; + else if (sysfs_streq(buf, modes[2])) + mode = 2; else return -EINVAL; twl4030_charger_enable_usb(bci, false); @@ -750,6 +784,17 @@ static int twl4030_bci_get_property(struct power_supply *psy, is_charging = state & TWL4030_MSTATEC_USB; else is_charging = state & TWL4030_MSTATEC_AC; + if (!is_charging) { + u8 s; + twl4030_bci_read(TWL4030_BCIMDEN, &s); + if (psy->desc->type == POWER_SUPPLY_TYPE_USB) + is_charging = s & 1; + else + is_charging = s & 2; + if (is_charging) + /* A little white lie */ + state = TWL4030_MSTATEC_QUICK1; + } switch (psp) { case POWER_SUPPLY_PROP_STATUS: -- 2.20.1