regulator: act8945a-regulator: unlock expert registers

Unlock expert registers for act8945a.
This is based on orginal work of Boris Brezillon at [1].

[1] https://www.spinics.net/lists/kernel/msg2942960.html

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/regulator/act8945a-regulator.c b/drivers/regulator/act8945a-regulator.c
index 43fda8b4455acd87d4c910d5ecfdb885759bba06..8d71d9893d0d7062d33d95f752f5ddd103ae421c 100644 (file)
--- a/drivers/regulator/act8945a-regulator.c
+++ b/drivers/regulator/act8945a-regulator.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 
@@ -23,6 +24,7 @@
  */
 #define ACT8945A_SYS_MODE      0x00
 #define ACT8945A_SYS_CTRL      0x01
+#define ACT8945A_SYS_UNLK_REGS 0x0b
 #define ACT8945A_DCDC1_VSET1   0x20
 #define ACT8945A_DCDC1_VSET2   0x21
 #define ACT8945A_DCDC1_CTRL    0x22
@@ -123,9 +125,17 @@ static int act8945a_pmic_probe(struct platform_device *pdev)
        struct regulator_config config = { };
        const struct regulator_desc *regulators;
        struct regulator_dev *rdev;
+       struct regmap *regmap;
        int i, num_regulators;
        bool voltage_select;
 
+       regmap = dev_get_regmap(pdev->dev.parent, NULL);
+       if (!regmap) {
+               dev_err(&pdev->dev,
+                       "could not retrieve regmap from parent device\n");
+               return -EINVAL;
+       }
+
        voltage_select = of_property_read_bool(pdev->dev.parent->of_node,
                                               "active-semi,vsel-high");
 
@@ -149,7 +159,8 @@ static int act8945a_pmic_probe(struct platform_device *pdev)
                }
        }
 
-       return 0;
+       /* Unlock expert registers. */
+       return regmap_write(regmap, ACT8945A_SYS_UNLK_REGS, 0xef);
 }
 
 static struct platform_driver act8945a_pmic_driver = {