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path: root/drivers/rtc/rtc-ds1307.c
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Diffstat (limited to 'drivers/rtc/rtc-ds1307.c')
-rw-r--r--drivers/rtc/rtc-ds1307.c76
1 files changed, 71 insertions, 5 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 54c85cdd019d..9f5f54ca039d 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -122,6 +122,9 @@ enum ds_type {
#define RX8130_REG_FLAG_AF BIT(3)
#define RX8130_REG_CONTROL0 0x1e
#define RX8130_REG_CONTROL0_AIE BIT(3)
+#define RX8130_REG_CONTROL1 0x1f
+#define RX8130_REG_CONTROL1_INIEN BIT(4)
+#define RX8130_REG_CONTROL1_CHGEN BIT(5)
#define MCP794XX_REG_CONTROL 0x07
# define MCP794XX_BIT_ALM0_EN 0x10
@@ -153,6 +156,7 @@ enum ds_type {
#define DS1388_REG_CONTROL 0x0c
# define DS1388_BIT_RST BIT(0)
# define DS1388_BIT_WDE BIT(1)
+# define DS1388_BIT_nEOSC BIT(7)
/* negative offset step is -2.034ppm */
#define M41TXX_NEG_OFFSET_STEP_PPB 2034
@@ -190,6 +194,15 @@ struct chip_desc {
u16 trickle_charger_reg;
u8 (*do_trickle_setup)(struct ds1307 *, u32,
bool);
+ /* Does the RTC require trickle-resistor-ohms to select the value of
+ * 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];
@@ -352,6 +365,10 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
regmap_update_bits(ds1307->regmap, DS1340_REG_FLAG,
DS1340_BIT_OSF, 0);
break;
+ case ds_1388:
+ regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG,
+ DS1388_BIT_OSF, 0);
+ break;
case mcp794xx:
/*
* these bits were cleared when preparing the date/time
@@ -507,6 +524,8 @@ static u8 do_trickle_setup_ds1339(struct ds1307 *ds1307, u32 ohms, bool diode)
u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
DS1307_TRICKLE_CHARGER_NO_DIODE;
+ setup |= DS13XX_TRICKLE_CHARGER_MAGIC;
+
switch (ohms) {
case 250:
setup |= DS1307_TRICKLE_CHARGER_250_OHM;
@@ -525,6 +544,16 @@ static u8 do_trickle_setup_ds1339(struct ds1307 *ds1307, u32 ohms, bool diode)
return setup;
}
+static u8 do_trickle_setup_rx8130(struct ds1307 *ds1307, u32 ohms, bool diode)
+{
+ /* make sure that the backup battery is enabled */
+ u8 setup = RX8130_REG_CONTROL1_INIEN;
+ if (diode)
+ setup |= RX8130_REG_CONTROL1_CHGEN;
+
+ return setup;
+}
+
static irqreturn_t rx8130_irq(int irq, void *dev_id)
{
struct ds1307 *ds1307 = dev_id;
@@ -979,6 +1008,8 @@ static const struct chip_desc chips[last_ds_type] = {
.bbsqi_bit = DS1339_BIT_BBSQI,
.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,
@@ -986,6 +1017,8 @@ static const struct chip_desc chips[last_ds_type] = {
.century_bit = DS1340_BIT_CENTURY,
.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,
@@ -1009,6 +1042,8 @@ static const struct chip_desc chips[last_ds_type] = {
.offset = 0x10,
.irq_handler = rx8130_irq,
.rtc_ops = &rx8130_rtc_ops,
+ .trickle_charger_reg = RX8130_REG_CONTROL1,
+ .do_trickle_setup = &do_trickle_setup_rx8130,
},
[m41t0] = {
.rtc_ops = &m41txx_rtc_ops,
@@ -1293,18 +1328,37 @@ static int ds1307_nvram_write(void *priv, unsigned int offset, void *val,
static u8 ds1307_trickle_init(struct ds1307 *ds1307,
const struct chip_desc *chip)
{
- u32 ohms;
- bool diode = true;
+ u32 ohms, chargeable;
+ bool diode = chip->charge_default;
if (!chip->do_trickle_setup)
return 0;
if (device_property_read_u32(ds1307->dev, "trickle-resistor-ohms",
- &ohms))
+ &ohms) && chip->requires_trickle_resistor)
return 0;
- if (device_property_read_bool(ds1307->dev, "trickle-diode-disable"))
+ /* aux-voltage-chargeable takes precedence over the deprecated
+ * trickle-diode-disable
+ */
+ if (!device_property_read_u32(ds1307->dev, "aux-voltage-chargeable",
+ &chargeable)) {
+ switch (chargeable) {
+ case 0:
+ diode = false;
+ break;
+ case 1:
+ diode = true;
+ break;
+ default:
+ dev_warn(ds1307->dev,
+ "unsupported aux-voltage-chargeable value\n");
+ break;
+ }
+ } else if (device_property_read_bool(ds1307->dev,
+ "trickle-diode-disable")) {
diode = false;
+ }
return chip->do_trickle_setup(ds1307, ohms, diode);
}
@@ -1758,7 +1812,6 @@ static int ds1307_probe(struct i2c_client *client,
trickle_charger_setup = pdata->trickle_charger_setup;
if (trickle_charger_setup && chip->trickle_charger_reg) {
- trickle_charger_setup |= DS13XX_TRICKLE_CHARGER_MAGIC;
dev_dbg(ds1307->dev,
"writing trickle charger info 0x%x to 0x%x\n",
trickle_charger_setup, chip->trickle_charger_reg);
@@ -1881,6 +1934,19 @@ static int ds1307_probe(struct i2c_client *client,
DS1307_REG_HOUR << 4 | 0x08, hour);
}
break;
+ case ds_1388:
+ err = regmap_read(ds1307->regmap, DS1388_REG_CONTROL, &tmp);
+ if (err) {
+ dev_dbg(ds1307->dev, "read error %d\n", err);
+ goto exit;
+ }
+
+ /* oscillator off? turn it on, so clock can tick. */
+ if (tmp & DS1388_BIT_nEOSC) {
+ tmp &= ~DS1388_BIT_nEOSC;
+ regmap_write(ds1307->regmap, DS1388_REG_CONTROL, tmp);
+ }
+ break;
default:
break;
}