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.vaitti...@nsn.com>
---
 .../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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