Hello,
I'm sorry to reply so late, I had to look into it first.
On 10/04/2019 11:26:58+0100, Phil Howard wrote:
> Adds support for the backup switchover mode register in the rv3028
> RTC. This allows the clock to automatically switch over to a backup
> power supply when the main power supply is lost.
>
This message should probably be moved...
> From 7ee04005288f0543debe46ed918b77374ad63adf Mon Sep 17 00:00:00 2001
> From: Phil Howard <phil@xxxxxxxxxxxxx>
> Date: Fri, 29 Mar 2019 10:53:14 +0000
> Subject: [PATCH 1/3] rtc: rv3028: Add backup switchover mode support
>
... here
> Signed-off-by: Phil Howard <phil@xxxxxxxxxxxx>
> ---
> drivers/rtc/rtc-rv3028.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/drivers/rtc/rtc-rv3028.c b/drivers/rtc/rtc-rv3028.c
> index d04c2d4816555..b69d8e6408aae 100644
> --- a/drivers/rtc/rtc-rv3028.c
> +++ b/drivers/rtc/rtc-rv3028.c
> @@ -74,6 +74,7 @@
>
> #define RV3028_BACKUP_TCE BIT(5)
> #define RV3028_BACKUP_TCR_MASK GENMASK(1,0)
> +#define RV3028_BACKUP_BSM_MASK 0x0C
>
> #define OFFSET_STEP_PPT 953674
>
> @@ -601,6 +602,7 @@ static int rv3028_probe(struct i2c_client *client)
> struct rv3028_data *rv3028;
> int ret, status;
> u32 ohms;
> + u8 bsm;
> struct nvmem_config nvmem_cfg = {
> .name = "rv3028_nvram",
> .word_size = 1,
> @@ -671,6 +673,21 @@ static int rv3028_probe(struct i2c_client *client)
> if (ret)
> return ret;
>
> + /* setup backup switchover mode */
> + if (!device_property_read_u8(&client->dev, "backup-switchover-mode",
> + &bsm)) {
> + if (bsm <= 3) {
> + ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP,
> + RV3028_BACKUP_BSM_MASK,
> + (bsm & 0x03) << 2);
> +
> + if (ret)
> + return ret;
> + } else {
> + dev_warn(&client->dev, "invalid backup switchover mode value\n");
> + }
> + }
> +
> /* setup trickle charger */
> if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
> &ohms)) {
>
> From ae9228b10d864368b934839156b6d9fa58fb5724 Mon Sep 17 00:00:00 2001
> From: Phil Howard <phil@xxxxxxxxxxxxx>
> Date: Fri, 29 Mar 2019 10:57:07 +0000
> Subject: [PATCH 2/3] dt-bindings: rv3028 backup switchover support
>
This needs a proper commit message. Also, please use git-send email
because both patches should be sent separately.
> Signed-off-by: Phil Howard <phil@xxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/rtc/rtc.txt | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/Documentation/devicetree/bindings/rtc/rtc.txt
> b/Documentation/devicetree/bindings/rtc/rtc.txt
> index 3e6a215e7304b..33fcad8754ec2 100644
> --- a/Documentation/devicetree/bindings/rtc/rtc.txt
> +++ b/Documentation/devicetree/bindings/rtc/rtc.txt
> @@ -26,6 +26,7 @@ below.
> - trickle-diode-disable : Do not use internal trickle charger diode Should be
> given if internal trickle charger diode should be
> disabled
> +- backup-switchover-mode : Configure RTC backup power supply switch behaviour
Because we want that property to be generic, I had a look at what the
other RTCs settings are:
- RV3028 has disabled, direct, standby and level switching
- Abracon (b5ze) has standard (VDD < threshold) and direct (VDD < VBAT),
this maps well to level and direct.
- Intersil (isl12026, isl1208, isl1219) has standard and legacy, this maps
to level and direct.
- I also took time to look at other RTCs, most of them only have an
enable/disable setting.
What I think is needed is to give meaningful names, using defines. We
can probably keep the BSM values (i.e 0 for disabled, 1 for direct, 2
for standby and 3 for threshold). I can take are of that part if you
want.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
