regulator: max8998 BUCK1/2 voltage change with use of GPIOs

max8998_pmic_probe:
- modified to check if valid pins are defined at platform
data
- maximal voltage values (predefined at platform data) are uploaded to
max8998 device

max8998_set_voltage_buck:
- BUCK1/2 voltages change between values already defined
- Checks if valid GPIO pins are passed from platform data
- If requested voltage cannot be satisfied from already defined values,
then one of free slots is used
- Predefined maximum voltages (as defined at platform data) are always
available

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 193 insertions, 21 deletions

diff --git a/drivers/regulator/max8998.c b/drivers/regulator/max8998.c
index 7ae0639c139..5c20756db60 100644
--- a/drivers/regulator/max8998.c
+++ b/drivers/regulator/max8998.c
@@ -340,24 +340,37 @@ static int max8998_set_voltage_ldo(struct regulator_dev *rdev,
         return ret;
 }
 
+static inline void buck1_gpio_set(int gpio1, int gpio2, int v)
+{
+        gpio_set_value(gpio1, v & 0x1);
+        gpio_set_value(gpio2, (v >> 1) & 0x1);
+}
+
+static inline void buck2_gpio_set(int gpio, int v)
+{
+        gpio_set_value(gpio, v & 0x1);
+}
+
 static int max8998_set_voltage_buck(struct regulator_dev *rdev,
-                                int min_uV, int max_uV)
+                                    int min_uV, int max_uV)
 {
         struct max8998_data *max8998 = rdev_get_drvdata(rdev);
+        struct max8998_platform_data *pdata =
+                dev_get_platdata(max8998->iodev->dev);
         struct i2c_client *i2c = max8998->iodev->i2c;
         int min_vol = min_uV / 1000, max_vol = max_uV / 1000;
-        int previous_vol = 0;
         const struct voltage_map_desc *desc;
-        int ldo = max8998_get_ldo(rdev);
+        int buck = max8998_get_ldo(rdev);
         int reg, shift = 0, mask, ret;
-        int i = 0;
-        u8 val;
-        bool en_ramp = false;
+        int difference = 0, i = 0, j = 0, previous_vol = 0;
+        u8 val = 0;
+        static u8 buck1_last_val;
 
-        if (ldo >= ARRAY_SIZE(ldo_voltage_map))
+        if (buck >= ARRAY_SIZE(ldo_voltage_map))
                 return -EINVAL;
 
-        desc = ldo_voltage_map[ldo];
+        desc = ldo_voltage_map[buck];
+
         if (desc == NULL)
                 return -EINVAL;
 
@@ -375,24 +388,102 @@ static int max8998_set_voltage_buck(struct regulator_dev *rdev,
         if (ret)
                 return ret;
 
-        /* wait for RAMP_UP_DELAY if rdev is BUCK1/2 and
-         * ENRAMP is ON */
-        if (ldo == MAX8998_BUCK1 || ldo == MAX8998_BUCK2) {
-                max8998_read_reg(i2c, MAX8998_REG_ONOFF4, &val);
-                if (val & (1 << 4)) {
-                        en_ramp = true;
-                        previous_vol = max8998_get_voltage(rdev);
-                }
+        previous_vol = max8998_get_voltage(rdev);
+
+        /* Check if voltage needs to be changed */
+        /* if previous_voltage equal new voltage, return */
+        if (previous_vol == max8998_list_voltage(rdev, i)) {
+                dev_dbg(max8998->dev, "No voltage change, old:%d, new:%d\n",
+                        previous_vol, max8998_list_voltage(rdev, i));
+                return ret;
         }
 
-        ret = max8998_update_reg(i2c, reg, i<<shift, mask<<shift);
+        switch (buck) {
+        case MAX8998_BUCK1:
+                dev_dbg(max8998->dev,
+                        "BUCK1, i:%d, buck1_vol1:%d, buck1_vol2:%d\n\
+                         buck1_vol3:%d, buck1_vol4:%d\n",
+                        i, max8998->buck1_vol[0], max8998->buck1_vol[1],
+                        max8998->buck1_vol[2], max8998->buck1_vol[3]);
+
+                if (gpio_is_valid(pdata->buck1_set1) &&
+                    gpio_is_valid(pdata->buck1_set2)) {
+
+                        /* check if requested voltage */
+                        /* value is already defined */
+                        for (j = 0; j < ARRAY_SIZE(max8998->buck1_vol); j++) {
+                                if (max8998->buck1_vol[j] == i) {
+                                        max8998->buck1_idx = j;
+                                        buck1_gpio_set(pdata->buck1_set1,
+                                                       pdata->buck1_set2, j);
+                                        goto buck1_exit;
+                                }
+                        }
+
+                        /* no predefine regulator found */
+                        max8998->buck1_idx = (buck1_last_val % 2) + 2;
+                        dev_dbg(max8998->dev, "max8998->buck1_idx:%d\n",
+                                max8998->buck1_idx);
+                        max8998->buck1_vol[max8998->buck1_idx] = i;
+                        ret = max8998_get_voltage_register(rdev, &reg,
+                                                           &shift,
+                                                           &mask);
+                        ret = max8998_write_reg(i2c, reg, i);
+                        buck1_gpio_set(pdata->buck1_set1,
+                                       pdata->buck1_set2, max8998->buck1_idx);
+                        buck1_last_val++;
+buck1_exit:
+                        dev_dbg(max8998->dev, "%s: SET1:%d, SET2:%d\n",
+                                i2c->name, gpio_get_value(pdata->buck1_set1),
+                                gpio_get_value(pdata->buck1_set2));
+                        break;
+                } else {
+                        ret = max8998_write_reg(i2c, reg, i);
+                }
+                break;
 
-        if (en_ramp == true) {
-                int difference = desc->min + desc->step*i - previous_vol/1000;
-                if (difference > 0)
-                        udelay(difference / ((val & 0x0f) + 1));
+        case MAX8998_BUCK2:
+                dev_dbg(max8998->dev,
+                        "BUCK2, i:%d buck2_vol1:%d, buck2_vol2:%d\n"
+                        , i, max8998->buck2_vol[0], max8998->buck2_vol[1]);
+                if (gpio_is_valid(pdata->buck2_set3)) {
+                        if (max8998->buck2_vol[0] == i) {
+                                max8998->buck1_idx = 0;
+                                buck2_gpio_set(pdata->buck2_set3, 0);
+                        } else {
+                                max8998->buck1_idx = 1;
+                                ret = max8998_get_voltage_register(rdev, &reg,
+                                                                   &shift,
+                                                                   &mask);
+                                ret = max8998_write_reg(i2c, reg, i);
+                                max8998->buck2_vol[1] = i;
+                                buck2_gpio_set(pdata->buck2_set3, 1);
+                        }
+                        dev_dbg(max8998->dev, "%s: SET3:%d\n", i2c->name,
+                                gpio_get_value(pdata->buck2_set3));
+                } else {
+                        ret = max8998_write_reg(i2c, reg, i);
+                }
+                break;
+
+        case MAX8998_BUCK3:
+        case MAX8998_BUCK4:
+                ret = max8998_update_reg(i2c, reg, i<<shift, mask<<shift);
+                break;
         }
 
+        /* Voltage stabilization */
+        max8998_read_reg(i2c, MAX8998_REG_ONOFF4, &val);
+
+        /* lp3974 hasn't got ENRAMP bit - ramp is assumed as true */
+        /* MAX8998 has ENRAMP bit implemented, so test it*/
+        if (max8998->iodev->type == TYPE_MAX8998 && !(val & MAX8998_ENRAMP))
+                return ret;
+
+        difference = desc->min + desc->step*i - previous_vol/1000;
+        if (difference > 0)
+                udelay(difference / ((val & 0x0f) + 1));
+
         return ret;
 }
 
@@ -586,6 +677,7 @@ static __devinit int max8998_pmic_probe(struct platform_device *pdev)
         struct max8998_platform_data *pdata = dev_get_platdata(iodev->dev);
         struct regulator_dev **rdev;
         struct max8998_data *max8998;
+        struct i2c_client *i2c;
         int i, ret, size;
 
         if (!pdata) {
@@ -609,6 +701,86 @@ static __devinit int max8998_pmic_probe(struct platform_device *pdev)
         max8998->iodev = iodev;
         max8998->num_regulators = pdata->num_regulators;
         platform_set_drvdata(pdev, max8998);
+        i2c = max8998->iodev->i2c;
+
+        /* NOTE: */
+        /* For unused GPIO NOT marked as -1 (thereof equal to 0)  WARN_ON */
+        /* will be displayed */
+
+        /* Check if MAX8998 voltage selection GPIOs are defined */
+        if (gpio_is_valid(pdata->buck1_set1) &&
+            gpio_is_valid(pdata->buck1_set2)) {
+                /* Check if SET1 is not equal to 0 */
+                if (!pdata->buck1_set1) {
+                        printk(KERN_ERR "MAX8998 SET1 GPIO defined as 0 !\n");
+                        WARN_ON(!pdata->buck1_set1);
+                        return -EIO;
+                }
+                /* Check if SET2 is not equal to 0 */
+                if (!pdata->buck1_set2) {
+                        printk(KERN_ERR "MAX8998 SET2 GPIO defined as 0 !\n");
+                        WARN_ON(!pdata->buck1_set2);
+                        return -EIO;
+                }
+
+                gpio_request(pdata->buck1_set1, "MAX8998 BUCK1_SET1");
+                gpio_direction_output(pdata->buck1_set1,
+                                      max8998->buck1_idx & 0x1);
+
+
+                gpio_request(pdata->buck1_set2, "MAX8998 BUCK1_SET2");
+                gpio_direction_output(pdata->buck1_set2,
+                                      (max8998->buck1_idx >> 1) & 0x1);
+                /* Set predefined value for BUCK1 register 1 */
+                i = 0;
+                while (buck12_voltage_map_desc.min +
+                       buck12_voltage_map_desc.step*i
+                       != (pdata->buck1_max_voltage1 / 1000))
+                        i++;
+                printk(KERN_ERR "i:%d, buck1_idx:%d\n", i, max8998->buck1_idx);
+                max8998->buck1_vol[0] = i;
+                ret = max8998_write_reg(i2c, MAX8998_REG_BUCK1_VOLTAGE1, i);
+
+                /* Set predefined value for BUCK1 register 2 */
+                i = 0;
+                while (buck12_voltage_map_desc.min +
+                       buck12_voltage_map_desc.step*i
+                       != (pdata->buck1_max_voltage2 / 1000))
+                        i++;
+
+                max8998->buck1_vol[1] = i;
+                printk(KERN_ERR "i:%d, buck1_idx:%d\n", i, max8998->buck1_idx);
+                ret = max8998_write_reg(i2c, MAX8998_REG_BUCK1_VOLTAGE2, i)
+                        + ret;
+                if (ret)
+                        return ret;
+
+        }
+
+        if (gpio_is_valid(pdata->buck2_set3)) {
+                /* Check if SET3 is not equal to 0 */
+                if (!pdata->buck2_set3) {
+                        printk(KERN_ERR "MAX8998 SET3 GPIO defined as 0 !\n");
+                        WARN_ON(!pdata->buck2_set3);
+                        return -EIO;
+                }
+                gpio_request(pdata->buck2_set3, "MAX8998 BUCK2_SET3");
+                gpio_direction_output(pdata->buck2_set3,
+                                      max8998->buck2_idx & 0x1);
+
+                /* BUCK2 - set preset default voltage value to buck2_vol[0] */
+                i = 0;
+                while (buck12_voltage_map_desc.min +
+                       buck12_voltage_map_desc.step*i
+                       != (pdata->buck2_max_voltage / 1000))
+                        i++;
+                printk(KERN_ERR "i:%d, buck2_idx:%d\n", i, max8998->buck2_idx);
+                max8998->buck2_vol[0] = i;
+                ret = max8998_write_reg(i2c, MAX8998_REG_BUCK2_VOLTAGE1, i);
+                if (ret)
+                        return ret;
+
+        }
 
         for (i = 0; i < pdata->num_regulators; i++) {
                 const struct voltage_map_desc *desc;