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-rw-r--r--drivers/mfd/max14577.c95
-rw-r--r--drivers/regulator/max14577.c80
-rw-r--r--include/linux/mfd/max14577-private.h22
-rw-r--r--include/linux/mfd/max14577.h23
4 files changed, 133 insertions, 87 deletions
diff --git a/drivers/mfd/max14577.c b/drivers/mfd/max14577.c
index 6599407b5624..b8af263be594 100644
--- a/drivers/mfd/max14577.c
+++ b/drivers/mfd/max14577.c
@@ -26,6 +26,87 @@
#include <linux/mfd/max14577.h>
#include <linux/mfd/max14577-private.h>
+/*
+ * Table of valid charger currents for different Maxim chipsets.
+ * It is placed here because it is used by both charger and regulator driver.
+ */
+const struct maxim_charger_current maxim_charger_currents[] = {
+ [MAXIM_DEVICE_TYPE_UNKNOWN] = { 0, 0, 0, 0 },
+ [MAXIM_DEVICE_TYPE_MAX14577] = {
+ .min = MAX14577_CHARGER_CURRENT_LIMIT_MIN,
+ .high_start = MAX14577_CHARGER_CURRENT_LIMIT_HIGH_START,
+ .high_step = MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP,
+ .max = MAX14577_CHARGER_CURRENT_LIMIT_MAX,
+ },
+ [MAXIM_DEVICE_TYPE_MAX77836] = {
+ .min = MAX77836_CHARGER_CURRENT_LIMIT_MIN,
+ .high_start = MAX77836_CHARGER_CURRENT_LIMIT_HIGH_START,
+ .high_step = MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP,
+ .max = MAX77836_CHARGER_CURRENT_LIMIT_MAX,
+ },
+};
+EXPORT_SYMBOL_GPL(maxim_charger_currents);
+
+/*
+ * maxim_charger_calc_reg_current - Calculate register value for current
+ * @limits: constraints for charger, matching the MBCICHWRC register
+ * @min_ua: minimal requested current, micro Amps
+ * @max_ua: maximum requested current, micro Amps
+ * @dst: destination to store calculated register value
+ *
+ * Calculates the value of MBCICHWRC (Fast Battery Charge Current) register
+ * for given current and stores it under pointed 'dst'. The stored value
+ * combines low bit (MBCICHWRCL) and high bits (MBCICHWRCH). It is also
+ * properly shifted.
+ *
+ * The calculated register value matches the current which:
+ * - is always between <limits.min, limits.max>;
+ * - is always less or equal to max_ua;
+ * - is the highest possible value;
+ * - may be lower than min_ua.
+ *
+ * On success returns 0. On error returns -EINVAL (requested min/max current
+ * is outside of given charger limits) and 'dst' is not set.
+ */
+int maxim_charger_calc_reg_current(const struct maxim_charger_current *limits,
+ unsigned int min_ua, unsigned int max_ua, u8 *dst)
+{
+ unsigned int current_bits = 0xf;
+
+ if (min_ua > max_ua)
+ return -EINVAL;
+
+ if (min_ua > limits->max || max_ua < limits->min)
+ return -EINVAL;
+
+ if (max_ua < limits->high_start) {
+ /*
+ * Less than high_start, so set the minimal current
+ * (turn Low Bit off, 0 as high bits).
+ */
+ *dst = 0x0;
+ return 0;
+ }
+
+ /* max_ua is in range: <high_start, infinite>, cut it to limits.max */
+ max_ua = min(limits->max, max_ua);
+ max_ua -= limits->high_start;
+ /*
+ * There is no risk of overflow 'max_ua' here because:
+ * - max_ua >= limits.high_start
+ * - BUILD_BUG checks that 'limits' are: max >= high_start + high_step
+ */
+ current_bits = max_ua / limits->high_step;
+
+ /* Turn Low Bit on (use range <limits.high_start, limits.max>) ... */
+ *dst = 0x1 << CHGCTRL4_MBCICHWRCL_SHIFT;
+ /* and set proper High Bits */
+ *dst |= current_bits << CHGCTRL4_MBCICHWRCH_SHIFT;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(maxim_charger_calc_reg_current);
+
static const struct mfd_cell max14577_devs[] = {
{
.name = "max14577-muic",
@@ -466,6 +547,20 @@ static int __init max14577_i2c_init(void)
BUILD_BUG_ON(ARRAY_SIZE(max14577_i2c_id) != MAXIM_DEVICE_TYPE_NUM);
BUILD_BUG_ON(ARRAY_SIZE(max14577_dt_match) != MAXIM_DEVICE_TYPE_NUM);
+ /* Valid charger current values must be provided for each chipset */
+ BUILD_BUG_ON(ARRAY_SIZE(maxim_charger_currents) != MAXIM_DEVICE_TYPE_NUM);
+
+ /* Check for valid values for charger */
+ BUILD_BUG_ON(MAX14577_CHARGER_CURRENT_LIMIT_HIGH_START +
+ MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP * 0xf !=
+ MAX14577_CHARGER_CURRENT_LIMIT_MAX);
+ BUILD_BUG_ON(MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP == 0);
+
+ BUILD_BUG_ON(MAX77836_CHARGER_CURRENT_LIMIT_HIGH_START +
+ MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP * 0xf !=
+ MAX77836_CHARGER_CURRENT_LIMIT_MAX);
+ BUILD_BUG_ON(MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP == 0);
+
return i2c_add_driver(&max14577_i2c_driver);
}
subsys_initcall(max14577_i2c_init);
diff --git a/drivers/regulator/max14577.c b/drivers/regulator/max14577.c
index 5d9c605cf534..0ff5a20ac958 100644
--- a/drivers/regulator/max14577.c
+++ b/drivers/regulator/max14577.c
@@ -22,42 +22,6 @@
#include <linux/mfd/max14577-private.h>
#include <linux/regulator/of_regulator.h>
-/*
- * Valid limits of current for max14577 and max77836 chargers.
- * They must correspond to MBCICHWRCL and MBCICHWRCH fields in CHGCTRL4
- * register for given chipset.
- */
-struct maxim_charger_current {
- /* Minimal current, set in CHGCTRL4/MBCICHWRCL, uA */
- unsigned int min;
- /*
- * Minimal current when high setting is active,
- * set in CHGCTRL4/MBCICHWRCH, uA
- */
- unsigned int high_start;
- /* Value of one step in high setting, uA */
- unsigned int high_step;
- /* Maximum current of high setting, uA */
- unsigned int max;
-};
-
-/* Table of valid charger currents for different Maxim chipsets */
-static const struct maxim_charger_current maxim_charger_currents[] = {
- [MAXIM_DEVICE_TYPE_UNKNOWN] = { 0, 0, 0, 0 },
- [MAXIM_DEVICE_TYPE_MAX14577] = {
- .min = MAX14577_REGULATOR_CURRENT_LIMIT_MIN,
- .high_start = MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_START,
- .high_step = MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_STEP,
- .max = MAX14577_REGULATOR_CURRENT_LIMIT_MAX,
- },
- [MAXIM_DEVICE_TYPE_MAX77836] = {
- .min = MAX77836_REGULATOR_CURRENT_LIMIT_MIN,
- .high_start = MAX77836_REGULATOR_CURRENT_LIMIT_HIGH_START,
- .high_step = MAX77836_REGULATOR_CURRENT_LIMIT_HIGH_STEP,
- .max = MAX77836_REGULATOR_CURRENT_LIMIT_MAX,
- },
-};
-
static int max14577_reg_is_enabled(struct regulator_dev *rdev)
{
int rid = rdev_get_id(rdev);
@@ -103,8 +67,8 @@ static int max14577_reg_get_current_limit(struct regulator_dev *rdev)
static int max14577_reg_set_current_limit(struct regulator_dev *rdev,
int min_uA, int max_uA)
{
- int i, current_bits = 0xf;
u8 reg_data;
+ int ret;
struct max14577 *max14577 = rdev_get_drvdata(rdev);
const struct maxim_charger_current *limits =
&maxim_charger_currents[max14577->dev_type];
@@ -112,35 +76,9 @@ static int max14577_reg_set_current_limit(struct regulator_dev *rdev,
if (rdev_get_id(rdev) != MAX14577_CHARGER)
return -EINVAL;
- if (min_uA > limits->max || max_uA < limits->min)
- return -EINVAL;
-
- if (max_uA < limits->high_start) {
- /*
- * Less than high_start,
- * so set the minimal current (turn only Low Bit off)
- */
- u8 reg_data = 0x0 << CHGCTRL4_MBCICHWRCL_SHIFT;
- return max14577_update_reg(rdev->regmap,
- MAX14577_CHG_REG_CHG_CTRL4,
- CHGCTRL4_MBCICHWRCL_MASK, reg_data);
- }
-
- /*
- * max_uA is in range: <high_start, inifinite>, so search for
- * valid current starting from maximum current.
- */
- for (i = limits->max; i >= limits->high_start; i -= limits->high_step) {
- if (i <= max_uA)
- break;
- current_bits--;
- }
- BUG_ON(current_bits < 0); /* Cannot happen */
-
- /* Turn Low Bit on (use range high_start-max)... */
- reg_data = 0x1 << CHGCTRL4_MBCICHWRCL_SHIFT;
- /* and set proper High Bits */
- reg_data |= current_bits << CHGCTRL4_MBCICHWRCH_SHIFT;
+ ret = maxim_charger_calc_reg_current(limits, min_uA, max_uA, &reg_data);
+ if (ret)
+ return ret;
return max14577_update_reg(rdev->regmap, MAX14577_CHG_REG_CHG_CTRL4,
CHGCTRL4_MBCICHWRCL_MASK | CHGCTRL4_MBCICHWRCH_MASK,
@@ -442,16 +380,6 @@ static struct platform_driver max14577_regulator_driver = {
static int __init max14577_regulator_init(void)
{
- /* Check for valid values for charger */
- BUILD_BUG_ON(MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_START +
- MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_STEP * 0xf !=
- MAX14577_REGULATOR_CURRENT_LIMIT_MAX);
- BUILD_BUG_ON(MAX77836_REGULATOR_CURRENT_LIMIT_HIGH_START +
- MAX77836_REGULATOR_CURRENT_LIMIT_HIGH_STEP * 0xf !=
- MAX77836_REGULATOR_CURRENT_LIMIT_MAX);
- /* Valid charger current values must be provided for each chipset */
- BUILD_BUG_ON(ARRAY_SIZE(maxim_charger_currents) != MAXIM_DEVICE_TYPE_NUM);
-
BUILD_BUG_ON(ARRAY_SIZE(max14577_supported_regulators) != MAX14577_REGULATOR_NUM);
BUILD_BUG_ON(ARRAY_SIZE(max77836_supported_regulators) != MAX77836_REGULATOR_NUM);
diff --git a/include/linux/mfd/max14577-private.h b/include/linux/mfd/max14577-private.h
index d6f321699b89..7d514839c764 100644
--- a/include/linux/mfd/max14577-private.h
+++ b/include/linux/mfd/max14577-private.h
@@ -281,17 +281,17 @@ enum max14577_charger_reg {
#define CHGCTRL7_OTPCGHCVS_SHIFT 0
#define CHGCTRL7_OTPCGHCVS_MASK (0x3 << CHGCTRL7_OTPCGHCVS_SHIFT)
-/* MAX14577 regulator current limits (as in CHGCTRL4 register), uA */
-#define MAX14577_REGULATOR_CURRENT_LIMIT_MIN 90000
-#define MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_START 200000
-#define MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_STEP 50000
-#define MAX14577_REGULATOR_CURRENT_LIMIT_MAX 950000
-
-/* MAX77836 regulator current limits (as in CHGCTRL4 register), uA */
-#define MAX77836_REGULATOR_CURRENT_LIMIT_MIN 45000
-#define MAX77836_REGULATOR_CURRENT_LIMIT_HIGH_START 100000
-#define MAX77836_REGULATOR_CURRENT_LIMIT_HIGH_STEP 25000
-#define MAX77836_REGULATOR_CURRENT_LIMIT_MAX 475000
+/* MAX14577 charger current limits (as in CHGCTRL4 register), uA */
+#define MAX14577_CHARGER_CURRENT_LIMIT_MIN 90000U
+#define MAX14577_CHARGER_CURRENT_LIMIT_HIGH_START 200000U
+#define MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP 50000U
+#define MAX14577_CHARGER_CURRENT_LIMIT_MAX 950000U
+
+/* MAX77836 charger current limits (as in CHGCTRL4 register), uA */
+#define MAX77836_CHARGER_CURRENT_LIMIT_MIN 45000U
+#define MAX77836_CHARGER_CURRENT_LIMIT_HIGH_START 100000U
+#define MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP 25000U
+#define MAX77836_CHARGER_CURRENT_LIMIT_MAX 475000U
/* MAX14577 regulator SFOUT LDO voltage, fixed, uV */
#define MAX14577_REGULATOR_SAFEOUT_VOLTAGE 4900000
diff --git a/include/linux/mfd/max14577.h b/include/linux/mfd/max14577.h
index c83fbed1c7b6..3c098d57b1d1 100644
--- a/include/linux/mfd/max14577.h
+++ b/include/linux/mfd/max14577.h
@@ -74,4 +74,27 @@ struct max14577_platform_data {
struct max14577_regulator_platform_data *regulators;
};
+/*
+ * Valid limits of current for max14577 and max77836 chargers.
+ * They must correspond to MBCICHWRCL and MBCICHWRCH fields in CHGCTRL4
+ * register for given chipset.
+ */
+struct maxim_charger_current {
+ /* Minimal current, set in CHGCTRL4/MBCICHWRCL, uA */
+ unsigned int min;
+ /*
+ * Minimal current when high setting is active,
+ * set in CHGCTRL4/MBCICHWRCH, uA
+ */
+ unsigned int high_start;
+ /* Value of one step in high setting, uA */
+ unsigned int high_step;
+ /* Maximum current of high setting, uA */
+ unsigned int max;
+};
+
+extern const struct maxim_charger_current maxim_charger_currents[];
+extern int maxim_charger_calc_reg_current(const struct maxim_charger_current *limits,
+ unsigned int min_ua, unsigned int max_ua, u8 *dst);
+
#endif /* __MAX14577_H__ */