[RESEND PATCH v3] rtc: ds1307: add trickle charger device tree binding
From: Matti Vaittinen
Date: Mon Sep 08 2014 - 02:29:53 EST
Hi dt bindings maintainers (and others interested in device-tree bindings),
I would like to get this included in your tree. Do you think there is
still something I could improve/change in order to get this accepted?
Or do you think I should address this to someone else?
Some DS13XX devices have "trickle chargers". Introduce a device tree binding
for specifying the trickle charger configuration for ds1339.
Signed-off-by: Matti Vaittinen <matti.vaittinen@xxxxxxx>
---
.../devicetree/bindings/i2c/trivial-devices.txt | 1 -
.../devicetree/bindings/rtc/dallas,ds1339.txt | 18 ++++++
drivers/rtc/rtc-ds1307.c | 66 ++++++++++++++++++++--
3 files changed, 80 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..fba65b2
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/dallas,ds1339.txt
@@ -0,0 +1,18 @@
+* Dallas DS1339 I2C Serial Real-Time Clock
+
+Required properties:
+- compatible: Should contain "dallas,ds1339".
+- reg: I2C address for chip
+
+Optional properties:
+- trickle-resistor-ohms : Selected resistor for trickle charger
+ Values usable for ds1339 are 250, 2000, 4000
+ Should be given if trickle charger should be enabled
+- trickle-diode-enable : Use internal trickle charger diode
+ Should be given if internal trickle charger diode should be enabled
+Example:
+ ds1339: rtc@68 {
+ compatible = "dallas,ds1339";
+ trickle-resistor-ohms = <250>;
+ reg = <0x68>;
+ };
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index f03d5ba..b297c2c 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -126,9 +126,14 @@ struct chip_desc {
u16 nvram_offset;
u16 nvram_size;
u16 trickle_charger_reg;
+ u8 trickle_charger_setup;
+ u8 (*do_trickle_setup)(struct i2c_client *, uint32_t, bool);
};
-static const struct chip_desc chips[last_ds_type] = {
+static u8 do_trickle_setup_ds1339(struct i2c_client *,
+ uint32_t ohms, bool diode);
+
+static struct chip_desc chips[last_ds_type] = {
[ds_1307] = {
.nvram_offset = 8,
.nvram_size = 56,
@@ -143,6 +148,7 @@ static const struct chip_desc chips[last_ds_type] = {
[ds_1339] = {
.alarm = 1,
.trickle_charger_reg = 0x10,
+ .do_trickle_setup = &do_trickle_setup_ds1339,
},
[ds_1340] = {
.trickle_charger_reg = 0x08,
@@ -833,15 +839,57 @@ ds1307_nvram_write(struct file *filp, struct kobject *kobj,
return count;
}
+
/*----------------------------------------------------------------------*/
+static u8 do_trickle_setup_ds1339(struct i2c_client *client,
+ uint32_t ohms, bool diode)
+{
+ u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
+ DS1307_TRICKLE_CHARGER_NO_DIODE;
+
+ switch (ohms) {
+ case 250:
+ setup |= DS1307_TRICKLE_CHARGER_250_OHM;
+ break;
+ case 2000:
+ setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
+ break;
+ case 4000:
+ setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
+ break;
+ default:
+ dev_warn(&client->dev,
+ "Unsupported ohm value %u in dt\n", ohms);
+ return 0;
+ }
+ return setup;
+}
+
+static void ds1307_trickle_of_init(struct i2c_client *client,
+ struct chip_desc *chip)
+{
+ uint32_t ohms = 0;
+ bool diode = false;
+
+ if (!chip->do_trickle_setup)
+ goto out;
+ if (of_property_read_u32(client->dev.of_node, "trickle-resistor-ohms" , &ohms))
+ goto out;
+ diode = of_property_read_bool(client->dev.of_node, "diode-connected");
+ chip->trickle_charger_setup = chip->do_trickle_setup(client,
+ ohms, diode);
+out:
+ return;
+}
+
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 +914,19 @@ 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)
+ ds1307_trickle_of_init(client, chip);
+ 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
--
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