hwmon: (ltc2978) Add support for LTC3882

LTC3882 is mostly compatible with LTC3880. Major differences are that it
does not measure the input current, and it no longer supports LTC's legacy
mechanism to identify the chip.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/Documentation/devicetree/bindings/hwmon/ltc2978.txt b/Documentation/devicetree/bindings/hwmon/ltc2978.txt
index ed2f09d..230389f 100644 (file)
--- a/Documentation/devicetree/bindings/hwmon/ltc2978.txt
+++ b/Documentation/devicetree/bindings/hwmon/ltc2978.txt
@@ -6,6 +6,7 @@ Required properties:
   * "lltc,ltc2977"
   * "lltc,ltc2978"
   * "lltc,ltc3880"
+  * "lltc,ltc3882"
   * "lltc,ltc3883"
   * "lltc,ltm4676"
 - reg: I2C slave address
@@ -20,7 +21,7 @@ Valid names of regulators depend on number of supplies supported per device:
   * ltc2974 : vout0 - vout3
   * ltc2977 : vout0 - vout7
   * ltc2978 : vout0 - vout7
-  * ltc3880 : vout0 - vout1
+  * ltc3880, ltc3882 : vout0 - vout1
   * ltc3883 : vout0
   * ltm4676 : vout0 - vout1
 

diff --git a/Documentation/hwmon/ltc2978 b/Documentation/hwmon/ltc2978
index 686c078..521ee8a 100644 (file)
--- a/Documentation/hwmon/ltc2978
+++ b/Documentation/hwmon/ltc2978
@@ -19,6 +19,10 @@ Supported chips:
     Prefix: 'ltc3880'
     Addresses scanned: -
     Datasheet: http://www.linear.com/product/ltc3880
+  * Linear Technology LTC3882
+    Prefix: 'ltc3882'
+    Addresses scanned: -
+    Datasheet: http://www.linear.com/product/ltc3882
   * Linear Technology LTC3883
     Prefix: 'ltc3883'
     Addresses scanned: -
@@ -34,11 +38,12 @@ Author: Guenter Roeck <linux@roeck-us.net>
 Description
 -----------
 
-LTC2974 is a quad digital power supply manager. LTC2978 is an octal power supply
-monitor. LTC2977 is a pin compatible replacement for LTC2978. LTC3880 is a dual
-output poly-phase step-down DC/DC controller. LTC3883 is a single phase
-step-down DC/DC controller. LTM4676 is a dual 13A or single 26A uModule
-regulator.
+LTC2974 is a quad digital power supply managers.
+LTC2978 is an octal power supply monitor.
+LTC2977 is a pin compatible replacement for LTC2978.
+LTC3880 and LTC3882 are dual output poly-phase step-down DC/DC controllers.
+LTC3883 is a single phase step-down DC/DC controller.
+LTM4676 is a dual 13A or single 26A uModule regulator.
 
 
 Usage Notes
@@ -80,7 +85,7 @@ in[N]_label           "vout[1-8]".
                        LTC2974: N=2-5
                        LTC2977: N=2-9
                        LTC2978: N=2-9
-                       LTC3880, LTM4676: N=2-3
+                       LTC3880, LTC3882, LTM4676: N=2-3
                        LTC3883: N=2
 in[N]_input            Measured output voltage.
 in[N]_min              Minimum output voltage.
@@ -100,8 +105,9 @@ temp[N]_input               Measured temperature.
                        and temp5 reports the chip temperature.
                        On LTC2977 and LTC2978, only one temperature measurement
                        is supported and reports the chip temperature.
-                       On LTC3880 and LTM4676, temp1 and temp2 report external
-                       temperatures, and temp3 reports the chip temperature.
+                       On LTC3880, LTC3882, and LTM4676, temp1 and temp2
+                       report external temperatures, and temp3 reports
+                       the chip temperature.
                        On LTC3883, temp1 reports an external temperature,
                        and temp2 reports the chip temperature.
 temp[N]_min            Mimimum temperature. LTC2974, LCT2977, and LTC2978 only.
@@ -128,7 +134,7 @@ power[N]_label              "pout[1-4]".
                        LTC2974: N=1-4
                        LTC2977: Not supported
                        LTC2978: Not supported
-                       LTC3880, LTM4676: N=1-2
+                       LTC3880, LTC3882, LTM4676: N=1-2
                        LTC3883: N=2
 power[N]_input         Measured output power.
 
@@ -143,7 +149,7 @@ curr[N]_label               "iout[1-4]".
                        LTC2974: N=1-4
                        LTC2977: not supported
                        LTC2978: not supported
-                       LTC3880, LTM4676: N=2-3
+                       LTC3880, LTC3882, LTM4676: N=2-3
                        LTC3883: N=2
 curr[N]_input          Measured output current.
 curr[N]_max            Maximum output current.

diff --git a/drivers/hwmon/pmbus/ltc2978.c b/drivers/hwmon/pmbus/ltc2978.c
index 7e10fbf..28e1e73 100644 (file)
--- a/drivers/hwmon/pmbus/ltc2978.c
+++ b/drivers/hwmon/pmbus/ltc2978.c
@@ -25,13 +25,13 @@
 #include <linux/regulator/driver.h>
 #include "pmbus.h"
 
-enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3883, ltm4676 };
+enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3882, ltc3883, ltm4676 };
 
 /* Common for all chips */
 #define LTC2978_MFR_VOUT_PEAK          0xdd
 #define LTC2978_MFR_VIN_PEAK           0xde
 #define LTC2978_MFR_TEMPERATURE_PEAK   0xdf
-#define LTC2978_MFR_SPECIAL_ID         0xe7
+#define LTC2978_MFR_SPECIAL_ID         0xe7    /* Not on LTC3882 */
 
 /* LTC2974, LCT2977, and LTC2978 */
 #define LTC2978_MFR_VOUT_MIN           0xfb
@@ -42,7 +42,7 @@ enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3883, ltm4676 };
 #define LTC2974_MFR_IOUT_PEAK          0xd7
 #define LTC2974_MFR_IOUT_MIN           0xd8
 
-/* LTC3880, LTC3883, and LTM4676 */
+/* LTC3880, LTC3882, LTC3883, and LTM4676 */
 #define LTC3880_MFR_IOUT_PEAK          0xd7
 #define LTC3880_MFR_CLEAR_PEAKS                0xe3
 #define LTC3880_MFR_TEMPERATURE2_PEAK  0xf4
@@ -313,7 +313,7 @@ static int ltc2978_clear_peaks(struct i2c_client *client, int page,
 {
        int ret;
 
-       if (id == ltc3880 || id == ltc3883 || id == ltm4676)
+       if (id == ltc3880 || id == ltc3882 || id == ltc3883 || id == ltm4676)
                ret = pmbus_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);
        else
                ret = pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS);
@@ -369,6 +369,7 @@ static const struct i2c_device_id ltc2978_id[] = {
        {"ltc2977", ltc2977},
        {"ltc2978", ltc2978},
        {"ltc3880", ltc3880},
+       {"ltc3882", ltc3882},
        {"ltc3883", ltc3883},
        {"ltm4676", ltm4676},
        {}
@@ -393,8 +394,30 @@ static int ltc2978_get_id(struct i2c_client *client)
        int chip_id;
 
        chip_id = i2c_smbus_read_word_data(client, LTC2978_MFR_SPECIAL_ID);
-       if (chip_id < 0)
-               return chip_id;
+       if (chip_id < 0) {
+               const struct i2c_device_id *id;
+               u8 buf[I2C_SMBUS_BLOCK_MAX];
+               int ret;
+
+               if (!i2c_check_functionality(client->adapter,
+                                            I2C_FUNC_SMBUS_READ_BLOCK_DATA))
+                       return -ENODEV;
+
+               ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
+               if (ret < 0)
+                       return ret;
+               if (ret < 3 || strncmp(buf, "LTC", 3))
+                       return -ENODEV;
+
+               ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
+               if (ret < 0)
+                       return ret;
+               for (id = &ltc2978_id[0]; strlen(id->name); id++) {
+                       if (!strncasecmp(id->name, buf, strlen(id->name)))
+                               return (int)id->driver_data;
+               }
+               return -ENODEV;
+       }
 
        if (chip_id == LTC2974_ID_REV1 || chip_id == LTC2974_ID_REV2)
                return ltc2974;
@@ -498,6 +521,20 @@ static int ltc2978_probe(struct i2c_client *client,
                  | PMBUS_HAVE_POUT
                  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
                break;
+       case ltc3882:
+               info->read_word_data = ltc3880_read_word_data;
+               info->pages = LTC3880_NUM_PAGES;
+               info->func[0] = PMBUS_HAVE_VIN
+                 | PMBUS_HAVE_STATUS_INPUT
+                 | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+                 | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+                 | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
+                 | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
+               info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+                 | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+                 | PMBUS_HAVE_POUT
+                 | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
+               break;
        case ltc3883:
                info->read_word_data = ltc3883_read_word_data;
                info->pages = LTC3883_NUM_PAGES;
@@ -530,6 +567,7 @@ static const struct of_device_id ltc2978_of_match[] = {
        { .compatible = "lltc,ltc2977" },
        { .compatible = "lltc,ltc2978" },
        { .compatible = "lltc,ltc3880" },
+       { .compatible = "lltc,ltc3882" },
        { .compatible = "lltc,ltc3883" },
        { .compatible = "lltc,ltm4676" },
        { }