diff mbox

[12/15] twl4030_charger: add software controlled linear charging mode.

Message ID 20150224043352.4243.11227.stgit@notabene.brown (mailing list archive)
State New, archived
Headers show

Commit Message

NeilBrown Feb. 24, 2015, 4:33 a.m. UTC
Add a 'continuous' option for usb charging which enabled
the "linear" charging mode of the twl4030.

Linear charging does a good job with not so reliable power sources, since
several voltage controlling is then often too intelligent.
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.

Orignal-by: Andreas Kemnade <andreas@kemnade.info>
Signed-off-by: NeilBrown <neilb@suse.de>
---
 drivers/power/twl4030_charger.c |   57 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 52 insertions(+), 5 deletions(-)



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Comments

Pavel Machek March 2, 2015, 9:09 p.m. UTC | #1
On Tue 2015-02-24 15:33:52, NeilBrown wrote:
> Add a 'continuous' option for usb charging which enabled
> the "linear" charging mode of the twl4030.

Documentation/ :-).

> Linear charging does a good job with not so reliable power sources, since
> several voltage controlling is then often too intelligent.

Parse error.

> 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.
> 
> Orignal-by: Andreas Kemnade <andreas@kemnade.info>
> Signed-off-by: NeilBrown <neilb@suse.de>


> +			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 */

USB

> +			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

Heat save? Is ignoring over-current good idea?

> @@ -650,6 +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;

Time for loop?
									Pavel
NeilBrown March 5, 2015, 6:33 a.m. UTC | #2
On Mon, 2 Mar 2015 22:09:26 +0100 Pavel Machek <pavel@ucw.cz> wrote:

> On Tue 2015-02-24 15:33:52, NeilBrown wrote:
> > Add a 'continuous' option for usb charging which enabled
> > the "linear" charging mode of the twl4030.
> 
> Documentation/ :-).

!

> 
> > Linear charging does a good job with not so reliable power sources, since
> > several voltage controlling is then often too intelligent.
> 
> Parse error.

========
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.
=========

> 
> > 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.
> > 
> > Orignal-by: Andreas Kemnade <andreas@kemnade.info>
> > Signed-off-by: NeilBrown <neilb@suse.de>
> 
> 
> > +			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 */
> 
> USB
> 
> > +			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
> 
> Heat save? Is ignoring over-current good idea?

The data sheet refers to a flag "HSEN" which is "Heat Save function enable".

your guess is as good as mine.

We don't currently have any code for responding to warnings.  Maybe we should.

For now this feature is "use at your own risk" - and one person has found it
very useful.

> 
> > @@ -650,6 +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;
> 
> Time for loop?

When we get one more mode it will be :-)

Thanks,
NeilBrown
diff mbox

Patch

diff --git a/drivers/power/twl4030_charger.c b/drivers/power/twl4030_charger.c
index 19e8dbb1303e..6c53f0b601a4 100644
--- a/drivers/power/twl4030_charger.c
+++ b/drivers/power/twl4030_charger.c
@@ -24,6 +24,8 @@ 
 #include <linux/usb/otg.h>
 #include <linux/i2c/twl4030-madc.h>
 
+#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)
@@ -110,6 +115,7 @@  struct twl4030_bci {
 	int			usb_mode; /* charging mode requested */
 #define	CHARGE_OFF	0
 #define	CHARGE_AUTO	1
+#define	CHARGE_LINEAR	2
 
 	unsigned long		event;
 };
@@ -392,16 +398,44 @@  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);
+			twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOAC|TWL4030_CVENAC);
+		}
 
 		/* 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);
@@ -637,7 +671,7 @@  static int twl4030_bci_usb_ncb(struct notifier_block *nb, unsigned long val,
 /*
  * sysfs charger enabled store
  */
-static char *modes[] = { "off", "auto" };
+static char *modes[] = { "off", "auto", "continuous" };
 static ssize_t
 twl4030_bci_mode_store(struct device *dev, struct device_attribute *attr,
 			  const char *buf, size_t n)
@@ -650,6 +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);
@@ -748,6 +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->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: