mfd: Introduce remove_script function for twl4030

New function twl4030_remove_script(u8 flags) takes a script type as
defined in twl.h and prevents any script already loaded in that position
from running.  This is accomplished by programming SEQ_ADD_* to 0x3f,
the END_OF_SCRIPT value, where SEQ_ADD_* is determined by flags.

(Future) users of this function include OMAP board files for machines
facing a race condition between sleep and warm reset.

Signed-off-by: Mike Turquette <mturquette@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

2 files changed, 51 insertions, 0 deletions

diff --git a/drivers/mfd/twl4030-power.c b/drivers/mfd/twl4030-power.c
index 5b045ff4a2c2..7efa8789a3a2 100644
--- a/drivers/mfd/twl4030-power.c
+++ b/drivers/mfd/twl4030-power.c
@@ -461,6 +461,56 @@ out:
         return err;
 }
 
+int twl4030_remove_script(u8 flags)
+{
+        int err = 0;
+
+        err = twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, R_KEY_1,
+                        R_PROTECT_KEY);
+        if (err) {
+                pr_err("twl4030: unable to unlock PROTECT_KEY\n");
+                return err;
+        }
+
+        err = twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, R_KEY_2,
+                        R_PROTECT_KEY);
+        if (err) {
+                pr_err("twl4030: unable to unlock PROTECT_KEY\n");
+                return err;
+        }
+
+        if (flags & TWL4030_WRST_SCRIPT) {
+                err = twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, END_OF_SCRIPT,
+                                R_SEQ_ADD_WARM);
+                if (err)
+                        return err;
+        }
+        if (flags & TWL4030_WAKEUP12_SCRIPT) {
+                if (err)
+                err = twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, END_OF_SCRIPT,
+                                R_SEQ_ADD_S2A12);
+                        return err;
+        }
+        if (flags & TWL4030_WAKEUP3_SCRIPT) {
+                err = twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, END_OF_SCRIPT,
+                                R_SEQ_ADD_S2A3);
+                if (err)
+                        return err;
+        }
+        if (flags & TWL4030_SLEEP_SCRIPT) {
+                err = twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, END_OF_SCRIPT,
+                                R_SEQ_ADD_A2S);
+                if (err)
+                        return err;
+        }
+
+        err = twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, 0, R_PROTECT_KEY);
+        if (err)
+                pr_err("TWL4030 Unable to relock registers\n");
+
+        return err;
+}
+
 void __init twl4030_power_init(struct twl4030_power_data *twl4030_scripts)
 {
         int err = 0;
diff --git a/include/linux/i2c/twl.h b/include/linux/i2c/twl.h
index 70d4caf48571..fb6784e86d5f 100644
--- a/include/linux/i2c/twl.h
+++ b/include/linux/i2c/twl.h
@@ -550,6 +550,7 @@ struct twl4030_power_data {
 };
 
 extern void twl4030_power_init(struct twl4030_power_data *triton2_scripts);
+extern int twl4030_remove_script(u8 flags);
 
 struct twl4030_codec_audio_data {
         unsigned int    audio_mclk;