rtc: rx8025: implement RX-8035 support
The RX-8035 is a newer RTC from EPSON that is very
similar to the RX-8025.
The key difference is in the oscillation stop (XSTP)
bit which is inverted on the RX-8035.
Signed-off-by: Mathew McBride <matt@traverse.com.au>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210709044518.28769-2-matt@traverse.com.au
diff --git a/drivers/rtc/rtc-rx8025.c b/drivers/rtc/rtc-rx8025.c
index c914091..d38aaf0 100644
--- a/drivers/rtc/rtc-rx8025.c
+++ b/drivers/rtc/rtc-rx8025.c
@@ -60,14 +60,23 @@
#define RX8025_ADJ_DATA_MAX 62
#define RX8025_ADJ_DATA_MIN -62
+enum rx_model {
+ model_rx_unknown,
+ model_rx_8025,
+ model_rx_8035,
+ model_last
+};
+
static const struct i2c_device_id rx8025_id[] = {
- { "rx8025", 0 },
+ { "rx8025", model_rx_8025 },
+ { "rx8035", model_rx_8035 },
{ }
};
MODULE_DEVICE_TABLE(i2c, rx8025_id);
struct rx8025_data {
struct rtc_device *rtc;
+ enum rx_model model;
u8 ctrl1;
};
@@ -100,10 +109,26 @@ static s32 rx8025_write_regs(const struct i2c_client *client,
length, values);
}
+static int rx8025_is_osc_stopped(enum rx_model model, int ctrl2)
+{
+ int xstp = ctrl2 & RX8025_BIT_CTRL2_XST;
+ /* XSTP bit has different polarity on RX-8025 vs RX-8035.
+ * RX-8025: 0 == oscillator stopped
+ * RX-8035: 1 == oscillator stopped
+ */
+
+ if (model == model_rx_8025)
+ xstp = !xstp;
+
+ return xstp;
+}
+
static int rx8025_check_validity(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
+ struct rx8025_data *drvdata = dev_get_drvdata(dev);
int ctrl2;
+ int xstp;
ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
if (ctrl2 < 0)
@@ -117,7 +142,8 @@ static int rx8025_check_validity(struct device *dev)
return -EINVAL;
}
- if (!(ctrl2 & RX8025_BIT_CTRL2_XST)) {
+ xstp = rx8025_is_osc_stopped(drvdata->model, ctrl2);
+ if (xstp) {
dev_warn(dev, "crystal stopped, date is invalid\n");
return -EINVAL;
}
@@ -127,6 +153,7 @@ static int rx8025_check_validity(struct device *dev)
static int rx8025_reset_validity(struct i2c_client *client)
{
+ struct rx8025_data *drvdata = i2c_get_clientdata(client);
int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
if (ctrl2 < 0)
@@ -134,22 +161,28 @@ static int rx8025_reset_validity(struct i2c_client *client)
ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET);
+ if (drvdata->model == model_rx_8025)
+ ctrl2 |= RX8025_BIT_CTRL2_XST;
+ else
+ ctrl2 &= ~(RX8025_BIT_CTRL2_XST);
+
return rx8025_write_reg(client, RX8025_REG_CTRL2,
- ctrl2 | RX8025_BIT_CTRL2_XST);
+ ctrl2);
}
static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
{
struct i2c_client *client = dev_id;
struct rx8025_data *rx8025 = i2c_get_clientdata(client);
- int status;
+ int status, xstp;
rtc_lock(rx8025->rtc);
status = rx8025_read_reg(client, RX8025_REG_CTRL2);
if (status < 0)
goto out;
- if (!(status & RX8025_BIT_CTRL2_XST))
+ xstp = rx8025_is_osc_stopped(rx8025->model, status);
+ if (xstp)
dev_warn(&client->dev, "Oscillation stop was detected,"
"you may have to readjust the clock\n");
@@ -519,6 +552,9 @@ static int rx8025_probe(struct i2c_client *client,
i2c_set_clientdata(client, rx8025);
+ if (id)
+ rx8025->model = id->driver_data;
+
err = rx8025_init_client(client);
if (err)
return err;