Hi,
On Thu, Aug 01, 2013 at 08:01:11PM +0530, Laxman Dewangan wrote:
> 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@xxxxxxxxxx>
> ---
> Changes from V1:
> - Converted DT property to boolean.
> - cleanups as use "...".
>
> .../devicetree/bindings/rtc/rtc-palmas.txt | 28 ++++++++++++++++
> drivers/rtc/rtc-palmas.c | 35 ++++++++++++++++++++
> 2 files changed, 63 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/rtc/rtc-palmas.txt
>
> diff --git a/Documentation/devicetree/bindings/rtc/rtc-palmas.txt b/Documentation/devicetree/bindings/rtc/rtc-palmas.txt
> new file mode 100644
> index 0000000..c8c9def
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/rtc-palmas.txt
> @@ -0,0 +1,28 @@
> +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,back-battery-charge-enable: The palmas series device like TPS65913 or
> + TPS80036 supports the battery backup for powering the RTC when main
> + battery is removed or in very low power state. This flag will enable
> + the backup battery charging.
> +- ti,back-charge-low-current: Configure lower charging current. Device supports the
> + charging current as < 100mA or >100mA. Low current will set as <100mA.
> +
> +Example:
> + palmas: tps65913@58 {
> + ...
> + palmas_rtc: rtc {
> + compatible = "ti,palmas-rtc";
> + interrupt-parent = <&palmas>;
> + interrupts = <8 0>;
> + ti,back-battery-charge-enable;
> + ti,back-charge-low-current;
> + };
> + ...
> + };
> diff --git a/drivers/rtc/rtc-palmas.c b/drivers/rtc/rtc-palmas.c
> index a1fecc8..7f34e33 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 low_bb_charging;
> +
> + if (pdev->dev.of_node) {
> + enable_bb_charging = of_property_read_bool(pdev->dev.of_node,
> + "ti,back-battery-charge-enable");
> + low_bb_charging = of_property_read_bool(pdev->dev.of_node,
> + "ti,back-charge-low-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 = 0;
> +
> + if (low_bb_charging)
> + reg |= PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG;
> +
> + 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;
> + }
I wonder if this should be exposed via power_supply class, although it's
not really a power supply. So perhaps not needed :-s
looks good though (can't test as I don't have any boards available right
now):
Reviewed-by: Felipe Balbi <balbi@xxxxxx>
--
balbi
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