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authorMarek Vasut <marex@denx.de>2019-01-29 12:40:28 +0100
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2019-01-30 16:09:36 +0100
commit75455e258ea2b3ea08f08edc41735a447c3e7711 (patch)
tree114d9cb608c5206ed172ef7311d436faeec89729 /drivers/rtc/rtc-abx80x.c
parenta26ec8857da387303c6121a8aff7b7544a981690 (diff)
rtc: abx80x: Configure reserved bits in RV1805
The RV1805 uses smaller package than the AB1805, discern those two chips based on the compatible value and configure reserved bits in the RV1805 to prevent current leakage and accidental test mode entry. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> To: linux-rtc@vger.kernel.org Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc/rtc-abx80x.c')
-rw-r--r--drivers/rtc/rtc-abx80x.c67
1 files changed, 65 insertions, 2 deletions
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 4d24f7288ad7..b76f65983658 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -46,6 +46,9 @@
#define ABX8XX_CTRL_ARST BIT(2)
#define ABX8XX_CTRL_12_24 BIT(6)
+#define ABX8XX_REG_CTRL2 0x11
+#define ABX8XX_CTRL2_RSVD BIT(5)
+
#define ABX8XX_REG_IRQ 0x12
#define ABX8XX_IRQ_AIE BIT(2)
#define ABX8XX_IRQ_IM_1_4 (0x3 << 5)
@@ -78,6 +81,9 @@
#define ABX8XX_REG_ID0 0x28
+#define ABX8XX_REG_OUT_CTRL 0x30
+#define ABX8XX_OUT_CTRL_EXDS BIT(4)
+
#define ABX8XX_REG_TRICKLE 0x20
#define ABX8XX_TRICKLE_CHARGE_ENABLE 0xa0
#define ABX8XX_TRICKLE_STANDARD_DIODE 0x8
@@ -86,7 +92,7 @@
static u8 trickle_resistors[] = {0, 3, 6, 11};
enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
- AB1801, AB1803, AB1804, AB1805, ABX80X};
+ AB1801, AB1803, AB1804, AB1805, RV1805, ABX80X};
struct abx80x_cap {
u16 pn;
@@ -103,6 +109,7 @@ static struct abx80x_cap abx80x_caps[] = {
[AB1803] = {.pn = 0x1803},
[AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true},
[AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
+ [RV1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
[ABX80X] = {.pn = 0}
};
@@ -723,6 +730,62 @@ static int abx80x_probe(struct i2c_client *client,
return -EIO;
}
+ /* Configure RV1805 specifics */
+ if (part == RV1805) {
+ /*
+ * Avoid accidentally entering test mode. This can happen
+ * on the RV1805 in case the reserved bit 5 in control2
+ * register is set. RV-1805-C3 datasheet indicates that
+ * the bit should be cleared in section 11h - Control2.
+ */
+ data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL2);
+ if (data < 0) {
+ dev_err(&client->dev,
+ "Unable to read control2 register\n");
+ return -EIO;
+ }
+
+ err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL2,
+ data & ~ABX8XX_CTRL2_RSVD);
+ if (err < 0) {
+ dev_err(&client->dev,
+ "Unable to write control2 register\n");
+ return -EIO;
+ }
+
+ /*
+ * Avoid extra power leakage. The RV1805 uses smaller
+ * 10pin package and the EXTI input is not present.
+ * Disable it to avoid leakage.
+ */
+ data = i2c_smbus_read_byte_data(client, ABX8XX_REG_OUT_CTRL);
+ if (data < 0) {
+ dev_err(&client->dev,
+ "Unable to read output control register\n");
+ return -EIO;
+ }
+
+ /*
+ * Write the configuration key register to enable access to
+ * the config2 register
+ */
+ err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
+ ABX8XX_CFG_KEY_MISC);
+ if (err < 0) {
+ dev_err(&client->dev,
+ "Unable to write configuration key\n");
+ return -EIO;
+ }
+
+ err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OUT_CTRL,
+ data | ABX8XX_OUT_CTRL_EXDS);
+ if (err < 0) {
+ dev_err(&client->dev,
+ "Unable to write output control register\n");
+ return -EIO;
+ }
+ }
+
/* part autodetection */
if (part == ABX80X) {
for (i = 0; abx80x_caps[i].pn; i++)
@@ -826,7 +889,7 @@ static const struct i2c_device_id abx80x_id[] = {
{ "ab1803", AB1803 },
{ "ab1804", AB1804 },
{ "ab1805", AB1805 },
- { "rv1805", AB1805 },
+ { "rv1805", RV1805 },
{ }
};
MODULE_DEVICE_TABLE(i2c, abx80x_id);