ad525x_dpot: add support for one time programmable pots

New parts supported:
	AD5170, AD5171, AD5172, AD5173, AD5273

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 150 insertions, 20 deletions

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 233886d00861..26386a92f5aa 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -24,7 +24,7 @@ config AD525X_DPOT
           AD5260, AD5262, AD5263, AD5290, AD5291, AD5292, AD5293,
           AD7376, AD8400, AD8402, AD8403, ADN2850, AD5241, AD5242,
           AD5243, AD5245, AD5246, AD5247, AD5248, AD5280, AD5282,
-          ADN2860
+          ADN2860, AD5273, AD5171, AD5170, AD5172, AD5173
           digital potentiometer chips.
 
           See Documentation/misc-devices/ad525x_dpot.txt for the
diff --git a/drivers/misc/ad525x_dpot-i2c.c b/drivers/misc/ad525x_dpot-i2c.c
index abba18efdde3..374352af7979 100644
--- a/drivers/misc/ad525x_dpot-i2c.c
+++ b/drivers/misc/ad525x_dpot-i2c.c
@@ -97,6 +97,11 @@ static const struct i2c_device_id ad_dpot_id[] = {
         {"ad5280", AD5280_ID},
         {"ad5282", AD5282_ID},
         {"adn2860", ADN2860_ID},
+        {"ad5273", AD5273_ID},
+        {"ad5171", AD5171_ID},
+        {"ad5170", AD5170_ID},
+        {"ad5172", AD5172_ID},
+        {"ad5173", AD5173_ID},
         {}
 };
 MODULE_DEVICE_TABLE(i2c, ad_dpot_id);
diff --git a/drivers/misc/ad525x_dpot.c b/drivers/misc/ad525x_dpot.c
index 255ba4b5e355..5e6fa8449e8b 100644
--- a/drivers/misc/ad525x_dpot.c
+++ b/drivers/misc/ad525x_dpot.c
@@ -47,6 +47,11 @@
  * AD5280               1               256             20, 50, 200
  * AD5282               2               256             20, 50, 200
  * ADN2860              3               512             25, 250
+ * AD5273               1               64              1, 10, 50, 100 (OTP)
+ * AD5171               1               64              5, 10, 50, 100 (OTP)
+ * AD5170               1               256             2.5, 10, 50, 100 (OTP)
+ * AD5172               2               256             2.5, 10, 50, 100 (OTP)
+ * AD5173               2               256             2.5, 10, 50, 100 (OTP)
  *
  * See Documentation/misc-devices/ad525x_dpot.txt for more info.
  *
@@ -84,7 +89,8 @@ struct dpot_data {
         unsigned uid;
         unsigned feat;
         unsigned wipers;
-        u16 rdac_cache[8];
+        u16 rdac_cache[MAX_RDACS];
+        DECLARE_BITMAP(otp_en_mask, MAX_RDACS);
 };
 
 static inline int dpot_read_d8(struct dpot_data *dpot)
@@ -162,6 +168,15 @@ static s32 dpot_read_i2c(struct dpot_data *dpot, u8 reg)
                 ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
                         0 : DPOT_AD5291_RDAC_AB;
                 return dpot_read_r8d8(dpot, ctrl);
+        case DPOT_UID(AD5170_ID):
+        case DPOT_UID(AD5171_ID):
+        case DPOT_UID(AD5273_ID):
+                        return dpot_read_d8(dpot);
+        case DPOT_UID(AD5172_ID):
+        case DPOT_UID(AD5173_ID):
+                ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
+                        0 : DPOT_AD5272_3_A0;
+                return dpot_read_r8d8(dpot, ctrl);
         default:
                 if ((reg & DPOT_REG_TOL) || (dpot->max_pos > 256))
                         return dpot_read_r8d16(dpot, (reg & 0xF8) |
@@ -242,7 +257,7 @@ static s32 dpot_write_spi(struct dpot_data *dpot, u8 reg, u16 value)
 static s32 dpot_write_i2c(struct dpot_data *dpot, u8 reg, u16 value)
 {
         /* Only write the instruction byte for certain commands */
-        unsigned ctrl = 0;
+        unsigned tmp = 0, ctrl = 0;
 
         switch (dpot->uid) {
         case DPOT_UID(AD5246_ID):
@@ -261,6 +276,37 @@ static s32 dpot_write_i2c(struct dpot_data *dpot, u8 reg, u16 value)
                         0 : DPOT_AD5291_RDAC_AB;
                 return dpot_write_r8d8(dpot, ctrl, value);
                 break;
+        case DPOT_UID(AD5171_ID):
+        case DPOT_UID(AD5273_ID):
+                if (reg & DPOT_ADDR_OTP) {
+                        tmp = dpot_read_d8(dpot);
+                        if (tmp >> 6) /* Ready to Program? */
+                                return -EFAULT;
+                        ctrl = DPOT_AD5273_FUSE;
+                }
+                return dpot_write_r8d8(dpot, ctrl, value);
+                break;
+        case DPOT_UID(AD5172_ID):
+        case DPOT_UID(AD5173_ID):
+                ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
+                        0 : DPOT_AD5272_3_A0;
+                if (reg & DPOT_ADDR_OTP) {
+                        tmp = dpot_read_r8d16(dpot, ctrl);
+                        if (tmp >> 14) /* Ready to Program? */
+                                return -EFAULT;
+                        ctrl |= DPOT_AD5270_2_3_FUSE;
+                }
+                return dpot_write_r8d8(dpot, ctrl, value);
+                break;
+        case DPOT_UID(AD5170_ID):
+                if (reg & DPOT_ADDR_OTP) {
+                        tmp = dpot_read_r8d16(dpot, tmp);
+                        if (tmp >> 14) /* Ready to Program? */
+                                return -EFAULT;
+                        ctrl = DPOT_AD5270_2_3_FUSE;
+                }
+                return dpot_write_r8d8(dpot, ctrl, value);
+                break;
         default:
                 if (reg & DPOT_ADDR_CMD)
                         return dpot_write_d8(dpot, reg);
@@ -292,6 +338,12 @@ static ssize_t sysfs_show_reg(struct device *dev,
         struct dpot_data *data = dev_get_drvdata(dev);
         s32 value;
 
+        if (reg & DPOT_ADDR_OTP_EN)
+                return sprintf(buf, "%s\n",
+                        test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask) ?
+                        "enabled" : "disabled");
+
+
         mutex_lock(&data->update_lock);
         value = dpot_read(data, reg);
         mutex_unlock(&data->update_lock);
@@ -320,6 +372,19 @@ static ssize_t sysfs_set_reg(struct device *dev,
         unsigned long value;
         int err;
 
+        if (reg & DPOT_ADDR_OTP_EN) {
+                if (!strncmp(buf, "enabled", sizeof("enabled")))
+                        set_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
+                else
+                        clear_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
+
+                return count;
+        }
+
+        if ((reg & DPOT_ADDR_OTP) &&
+                !test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask))
+                return -EPERM;
+
         err = strict_strtoul(buf, 10, &value);
         if (err)
                 return err;
@@ -331,6 +396,8 @@ static ssize_t sysfs_set_reg(struct device *dev,
         dpot_write(data, reg, value);
         if (reg & DPOT_ADDR_EEPROM)
                 msleep(26);     /* Sleep while the EEPROM updates */
+        else if (reg & DPOT_ADDR_OTP)
+                msleep(400);    /* Sleep while the OTP updates */
         mutex_unlock(&data->update_lock);
 
         return count;
@@ -378,26 +445,38 @@ static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, NULL);
 DPOT_DEVICE_SHOW_SET(rdac0, DPOT_ADDR_RDAC | DPOT_RDAC0);
 DPOT_DEVICE_SHOW_SET(eeprom0, DPOT_ADDR_EEPROM | DPOT_RDAC0);
 DPOT_DEVICE_SHOW_ONLY(tolerance0, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC0);
+DPOT_DEVICE_SHOW_SET(otp0, DPOT_ADDR_OTP | DPOT_RDAC0);
+DPOT_DEVICE_SHOW_SET(otp0en, DPOT_ADDR_OTP_EN | DPOT_RDAC0);