[PATCH] rtc: ds1307: add trickle charger device tree binding

Matti Vaittinen
2014-08-28T11:40:13Z

Patch adding support for specifying trickle charger setup from device
tree. Patch is based on linux-next tree.

Some DS13XX devices have "trickle chargers". Introduce a device tree binding
for specifying the setup and register values.

Signed-off-by: Matti Vaittinen <matti.vaittinen@nsn.com>
---
.../devicetree/bindings/i2c/trivial-devices.txt | 1 -
.../devicetree/bindings/rtc/dallas,ds1339.txt | 19 ++++++++++
drivers/rtc/rtc-ds1307.c | 44 ++++++++++++++++++++--
3 files changed, 59 insertions(+), 5 deletions(-)
create mode 100644 Documentation/devicetree/bindings/rtc/dallas,ds1339.txt

diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
index 6af570e..e9206a4 100644
--- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
+++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
@@ -35,7 +35,6 @@ catalyst,24c32 i2c serial eeprom
cirrus,cs42l51 Cirrus Logic CS42L51 audio codec
dallas,ds1307 64 x 8, Serial, I2C Real-Time Clock
dallas,ds1338 I2C RTC with 56-Byte NV RAM
-dallas,ds1339 I2C Serial Real-Time Clock
dallas,ds1340 I2C RTC with Trickle Charger
dallas,ds1374 I2C, 32-Bit Binary Counter Watchdog RTC with Trickle Charger and Reset Input/Output
dallas,ds1631 High-Precision Digital Thermometer
diff --git a/Documentation/devicetree/bindings/rtc/dallas,ds1339.txt b/Documentation/devicetree/bindings/rtc/dallas,ds1339.txt
new file mode 100644
index 0000000..9faf40e
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/dallas,ds1339.txt
@@ -0,0 +1,19 @@
+* Dallas DS1339 I2C Serial Real-Time Clock
+
+Required properties:
+- compatible: Should contain "dallas,ds1339".
+- reg: I2C address for chip
+
+Optional properties:
+- trickle_setup : Used Trickle Charger configuration,
+ corresponding to 5 lowest bits in trickle charger register.
+- trickle_reg : Trickle charger register address. Defaults to 0x10 for ds1339.
+
+Example:
+ ds1339: rtc@68 {
+ compatible = "dallas,ds1339";
+ trickle_setup= <0x5>;
+ reg = <0x68>;
+ };
+
+
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index f03d5ba..f9b1244 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -126,9 +126,10 @@ struct chip_desc {
u16 nvram_offset;
u16 nvram_size;
u16 trickle_charger_reg;
+ u8 trickle_charger_setup;
};

-static const struct chip_desc chips[last_ds_type] = {
+static struct chip_desc chips[last_ds_type] = {
[ds_1307] = {
.nvram_offset = 8,
.nvram_size = 56,
@@ -835,13 +836,37 @@ ds1307_nvram_write(struct file *filp, struct kobject *kobj,

/*----------------------------------------------------------------------*/

+static void trickle_charger_of_init(struct chip_desc *chip,
+ struct device_node *node)
+{
+ int plen = 0;
+ const uint32_t *setup;
+ const uint32_t *reg;
+
+ setup = of_get_property(node, "trickle_setup" , &plen);
+ if (plen != 4)
+ goto out;
+ chip->trickle_charger_setup = (u8)*setup;
+ plen = 0;
+ reg = of_get_property(node, "trickle_reg" , &plen);
+ if (plen == 4)
+ chip->trickle_charger_reg = (u16)*reg;
+ return;
+out:
+ pr_debug("%s: No trickle charger data in dt for %s rtc chip\n",
+ __func__, (node && node->name)?node->name:"ds13XX");
+}
+
+/*----------------------------------------------------------------------*/
+
+
static int ds1307_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ds1307 *ds1307;
int err = -ENODEV;
int tmp;
- const struct chip_desc *chip = &chips[id->driver_data];
+ struct chip_desc *chip = &chips[id->driver_data];
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
bool want_irq = false;
unsigned char *buf;
@@ -866,9 +891,20 @@ static int ds1307_probe(struct i2c_client *client,
ds1307->client = client;
ds1307->type = id->driver_data;

- if (pdata && pdata->trickle_charger_setup && chip->trickle_charger_reg)
+ if (!pdata && client->dev.of_node)
+ trickle_charger_of_init(chip, client->dev.of_node);
+ /* Get trickle property */
+ else if (pdata && pdata->trickle_charger_setup)
+ chip->trickle_charger_setup = pdata->trickle_charger_setup;
+
+ if (chip->trickle_charger_setup && chip->trickle_charger_reg) {
+ dev_dbg(&client->dev, "writing trickle charger info 0x%x to 0x%x\n",
+ DS13XX_TRICKLE_CHARGER_MAGIC | chip->trickle_charger_setup,
+ chip->trickle_charger_reg);
i2c_smbus_write_byte_data(client, chip->trickle_charger_reg,
- DS13XX_TRICKLE_CHARGER_MAGIC | pdata->trickle_charger_setup);
+ DS13XX_TRICKLE_CHARGER_MAGIC |
+ chip->trickle_charger_setup);
+ }

buf = ds1307->regs;
if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
--
1.8.3.1

--
=============================================

Matti Vaittinen
Senile SW Specialist
FINLAND

~~ When things go utterly wrong vim users can always type :help! ~~