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authorLaxman Dewangan <ldewangan@nvidia.com>2013-09-11 14:24:19 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-11 15:58:55 -0700
commit666a584d3a765a914642f80deef7a33fb309df5d (patch)
tree44075201728ea751d07c63ce5458e4cfd0404e92
parent8af750e3f5ca21eaa5595a96a4cf5eaa996deed4 (diff)
downloadlinux-666a584d3a765a914642f80deef7a33fb309df5d.tar.bz2
drivers/rtc/rtc-palmas.c: support for backup battery charging
Palmas series device like TPS65913, TPS80036 supports the backup battery for powering the RTC when no other energy source is available. The backup battery is optional, connected to the VBACKUP pin, and can be nonrechargeable or rechargeable. The rechargeable battery can be charged from the system supply using the backup battery charger. Add support for enabling charging of this backup battery. Also add the DT binding document and the new properties to have this support. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Reviewed-by: Felipe Balbi <balbi@ti.com> Acked-by: Kumar Gala <galak@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--Documentation/devicetree/bindings/rtc/rtc-palmas.txt33
-rw-r--r--drivers/rtc/rtc-palmas.c35
2 files changed, 68 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/rtc/rtc-palmas.txt b/Documentation/devicetree/bindings/rtc/rtc-palmas.txt
new file mode 100644
index 000000000000..adbccc0a51e1
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/rtc-palmas.txt
@@ -0,0 +1,33 @@
+Palmas RTC controller bindings
+
+Required properties:
+- compatible:
+ - "ti,palmas-rtc" for palma series of the RTC controller
+- interrupt-parent: Parent interrupt device, must be handle of palmas node.
+- interrupts: Interrupt number of RTC submodule on device.
+
+Optional properties:
+
+- ti,backup-battery-chargeable: The Palmas series device like TPS65913 or
+ TPS80036 supports the backup battery for powering the RTC when main
+ battery is removed or in very low power state. The backup battery
+ can be chargeable or non-chargeable. This flag will tells whether
+ battery is chargeable or not. If charging battery then driver can
+ enable the charging.
+- ti,backup-battery-charge-high-current: Enable high current charging in
+ backup battery. Device supports the < 100mA and > 100mA charging.
+ The high current will be > 100mA. Absence of this property will
+ charge battery to lower current i.e. < 100mA.
+
+Example:
+ palmas: tps65913@58 {
+ ...
+ palmas_rtc: rtc {
+ compatible = "ti,palmas-rtc";
+ interrupt-parent = <&palmas>;
+ interrupts = <8 0>;
+ ti,backup-battery-chargeable;
+ ti,backup-battery-charge-high-current;
+ };
+ ...
+ };
diff --git a/drivers/rtc/rtc-palmas.c b/drivers/rtc/rtc-palmas.c
index a1fecc8d97fc..fffb7d3449d7 100644
--- a/drivers/rtc/rtc-palmas.c
+++ b/drivers/rtc/rtc-palmas.c
@@ -238,6 +238,15 @@ static int palmas_rtc_probe(struct platform_device *pdev)
struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
struct palmas_rtc *palmas_rtc = NULL;
int ret;
+ bool enable_bb_charging = false;
+ bool high_bb_charging;
+
+ if (pdev->dev.of_node) {
+ enable_bb_charging = of_property_read_bool(pdev->dev.of_node,
+ "ti,backup-battery-chargeable");
+ high_bb_charging = of_property_read_bool(pdev->dev.of_node,
+ "ti,backup-battery-charge-high-current");
+ }
palmas_rtc = devm_kzalloc(&pdev->dev, sizeof(struct palmas_rtc),
GFP_KERNEL);
@@ -254,6 +263,32 @@ static int palmas_rtc_probe(struct platform_device *pdev)
palmas_rtc->dev = &pdev->dev;
platform_set_drvdata(pdev, palmas_rtc);
+ if (enable_bb_charging) {
+ unsigned reg = PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG;
+
+ if (high_bb_charging)
+ reg = 0;
+
+ ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
+ PALMAS_BACKUP_BATTERY_CTRL,
+ PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG, reg);
+ if (ret < 0) {
+ dev_err(&pdev->dev,
+ "BACKUP_BATTERY_CTRL update failed, %d\n", ret);
+ return ret;
+ }
+
+ ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
+ PALMAS_BACKUP_BATTERY_CTRL,
+ PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN,
+ PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN);
+ if (ret < 0) {
+ dev_err(&pdev->dev,
+ "BACKUP_BATTERY_CTRL update failed, %d\n", ret);
+ return ret;
+ }
+ }
+
/* Start RTC */
ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
PALMAS_RTC_CTRL_REG_STOP_RTC,