From 95a74cbb21a2431dd2fd8918fa26113629b6e13e Mon Sep 17 00:00:00 2001 From: Bastian Krause Date: Thu, 17 Sep 2020 20:32:44 +0200 Subject: [PATCH] rtc: ds1307: store previous charge default per chip Some RTC's batteries and supercaps were charged by default until now. In contrast other RTCs allow charging but the driver did not configure them to do so until now. These must not be charged by default to stay backwards compatible. In order to do that, store the charge default per chip. Signed-off-by: Bastian Krause Signed-off-by: Alexandre Belloni Link: https://lore.kernel.org/r/20200917183246.19446-7-bst@pengutronix.de --- drivers/rtc/rtc-ds1307.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 64fa1318817c..fdd6f9fda6f9 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -195,6 +195,11 @@ struct chip_desc { * the resistor between Vcc and Vbackup? */ bool requires_trickle_resistor; + /* Some RTC's batteries and supercaps were charged by default, others + * allow charging but were not configured previously to do so. + * Remember this behavior to stay backwards compatible. + */ + bool charge_default; }; static const struct chip_desc chips[last_ds_type]; @@ -991,6 +996,7 @@ static const struct chip_desc chips[last_ds_type] = { .trickle_charger_reg = 0x10, .do_trickle_setup = &do_trickle_setup_ds1339, .requires_trickle_resistor = true, + .charge_default = true, }, [ds_1340] = { .century_reg = DS1307_REG_HOUR, @@ -999,6 +1005,7 @@ static const struct chip_desc chips[last_ds_type] = { .do_trickle_setup = &do_trickle_setup_ds1339, .trickle_charger_reg = 0x08, .requires_trickle_resistor = true, + .charge_default = true, }, [ds_1341] = { .century_reg = DS1307_REG_MONTH, @@ -1307,7 +1314,7 @@ static u8 ds1307_trickle_init(struct ds1307 *ds1307, const struct chip_desc *chip) { u32 ohms; - bool diode = true; + bool diode = chip->charge_default; if (!chip->do_trickle_setup) return 0;