[PATCH v2 3/5] charger: max14577: Configure battery-dependent settings from DTS

From: Krzysztof Kozlowski
Date: Fri Jul 04 2014 - 03:59:36 EST

Remove hard-coded values for:
- Fast Charge current,
- End Of Charge current,
- Fast Charge timer,
- Overvoltage Protection Threshold,
- Battery Constant Voltage,
and use DTS to configure them. This allows using the max14577 charger
driver with different batteries.

Now the charger driver requires valid configuration data from DTS. In
case of wrong configuration data it fails during probe. Patch adds
of_compatible to the charger mfd cell in MFD driver core.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
Cc: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Jenny Tc <jenny.tc@xxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>
---
drivers/mfd/max14577.c | 5 +-
drivers/power/max14577_charger.c | 240 +++++++++++++++++++++++++++++++----
include/linux/mfd/max14577-private.h | 16 +++
include/linux/mfd/max14577.h | 8 ++
4 files changed, 241 insertions(+), 28 deletions(-)

diff --git a/drivers/mfd/max14577.c b/drivers/mfd/max14577.c
index e6f25aa0ded8..b8af263be594 100644
--- a/drivers/mfd/max14577.c
+++ b/drivers/mfd/max14577.c
@@ -116,7 +116,10 @@ static const struct mfd_cell max14577_devs[] = {
.name = "max14577-regulator",
.of_compatible = "maxim,max14577-regulator",
},
- { .name = "max14577-charger", },
+ {
+ .name = "max14577-charger",
+ .of_compatible = "maxim,max14577-charger",
+ },
};

static const struct mfd_cell max77836_devs[] = {
diff --git a/drivers/power/max14577_charger.c b/drivers/power/max14577_charger.c
index 19c8f42abf24..ce0e3b652255 100644
--- a/drivers/power/max14577_charger.c
+++ b/drivers/power/max14577_charger.c
@@ -19,6 +19,7 @@
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/mfd/max14577-private.h>
+#include <linux/mfd/max14577.h>

struct max14577_charger {
struct device *dev;
@@ -27,6 +28,8 @@ struct max14577_charger {

unsigned int charging_state;
unsigned int battery_state;
+
+ struct max14577_charger_platform_data *pdata;
};

/*
@@ -178,15 +181,107 @@ static int max14577_get_present(struct max14577_charger *chg)
return 1;
}

+static inline int max14577_init_constant_voltage(struct max14577_charger *chg,
+ unsigned int uvolt)
+{
+ u8 reg_data;
+
+ if (uvolt < MAXIM_CHARGER_CONSTANT_VOLTAGE_MIN ||
+ uvolt > MAXIM_CHARGER_CONSTANT_VOLTAGE_MAX)
+ return -EINVAL;
+
+ if (uvolt == 4200000)
+ reg_data = 0x0;
+ else if (uvolt == MAXIM_CHARGER_CONSTANT_VOLTAGE_MAX)
+ reg_data = 0x1f;
+ else if (uvolt <= 4280000) {
+ unsigned int val = uvolt;
+
+ val -= MAXIM_CHARGER_CONSTANT_VOLTAGE_MIN;
+ val /= MAXIM_CHARGER_CONSTANT_VOLTAGE_STEP;
+ if (uvolt <= 4180000)
+ reg_data = 0x1 + val;
+ else
+ reg_data = val; /* Fix for gap between 4.18V and 4.22V */
+ } else
+ return -EINVAL;
+
+ reg_data <<= CHGCTRL3_MBCCVWRC_SHIFT;
+
+ return max14577_write_reg(chg->max14577->regmap,
+ MAX14577_CHG_REG_CHG_CTRL3, reg_data);
+}
+
+static inline int max14577_init_eoc(struct max14577_charger *chg,
+ unsigned int uamp)
+{
+ unsigned int current_bits = 0xf;
+ u8 reg_data;
+
+ switch (chg->max14577->dev_type) {
+ case MAXIM_DEVICE_TYPE_MAX77836:
+ if (uamp < 5000)
+ return -EINVAL; /* Requested current is too low */
+
+ if (uamp >= 7500 && uamp < 10000)
+ current_bits = 0x0;
+ else if (uamp <= 50000) {
+ /* <5000, 7499> and <10000, 50000> */
+ current_bits = uamp / 5000;
+ } else {
+ uamp = min(uamp, 100000U) - 50000U;
+ current_bits = 0xa + uamp / 10000;
+ }
+ break;
+
+ case MAXIM_DEVICE_TYPE_MAX14577:
+ default:
+ if (uamp < MAX14577_CHARGER_EOC_CURRENT_LIMIT_MIN)
+ return -EINVAL; /* Requested current is too low */
+
+ uamp = min(uamp, MAX14577_CHARGER_EOC_CURRENT_LIMIT_MAX);
+ uamp -= MAX14577_CHARGER_EOC_CURRENT_LIMIT_MIN;
+ current_bits = uamp / MAX14577_CHARGER_EOC_CURRENT_LIMIT_STEP;
+ break;
+ }
+
+ reg_data = current_bits << CHGCTRL5_EOCS_SHIFT;
+
+ return max14577_update_reg(chg->max14577->regmap,
+ MAX14577_CHG_REG_CHG_CTRL5, CHGCTRL5_EOCS_MASK,
+ reg_data);
+}
+
+static inline int max14577_init_fast_charge(struct max14577_charger *chg,
+ unsigned int uamp)
+{
+ u8 reg_data;
+ int ret;
+ const struct maxim_charger_current *limits =
+ &maxim_charger_currents[chg->max14577->dev_type];
+
+ ret = maxim_charger_calc_reg_current(limits, uamp, uamp, &reg_data);
+ if (ret) {
+ dev_err(chg->dev, "Wrong value for fast charge: %u\n", uamp);
+ return ret;
+ }
+
+ return max14577_update_reg(chg->max14577->regmap,
+ MAX14577_CHG_REG_CHG_CTRL4,
+ CHGCTRL4_MBCICHWRCL_MASK | CHGCTRL4_MBCICHWRCH_MASK,
+ reg_data);
+}
+
/*
* Sets charger registers to proper and safe default values.
* Some of these values are equal to defaults in MAX14577E
* data sheet but there are minor differences.
*/
-static void max14577_charger_reg_init(struct max14577_charger *chg)
+static int max14577_charger_reg_init(struct max14577_charger *chg)
{
struct regmap *rmap = chg->max14577->regmap;
u8 reg_data;
+ int ret;

/*
* Charger-Type Manual Detection, default off (set CHGTYPMAN to 0)
@@ -198,10 +293,6 @@ static void max14577_charger_reg_init(struct max14577_charger *chg)
CDETCTRL1_CHGDETEN_MASK | CDETCTRL1_CHGTYPMAN_MASK,
reg_data);

- /* Battery Fast-Charge Timer, set to: 6hrs */
- reg_data = 0x3 << CHGCTRL1_TCHW_SHIFT;
- max14577_write_reg(rmap, MAX14577_REG_CHGCTRL1, reg_data);
-
/*
* Wall-Adapter Rapid Charge, default on
* Battery-Charger, default on
@@ -210,32 +301,57 @@ static void max14577_charger_reg_init(struct max14577_charger *chg)
reg_data |= 0x1 << CHGCTRL2_MBCHOSTEN_SHIFT;
max14577_write_reg(rmap, MAX14577_REG_CHGCTRL2, reg_data);

- /* Battery-Charger Constant Voltage (CV) Mode, set to: 4.35V */
- reg_data = 0xf << CHGCTRL3_MBCCVWRC_SHIFT;
- max14577_write_reg(rmap, MAX14577_REG_CHGCTRL3, reg_data);
-
- /*
- * Fast Battery-Charge Current Low,
- * default 200-950mA (max14577) / 100-475mA (max77836)
- *
- * Fast Battery-Charge Current High,
- * set to 450mA (max14577) / 225mA (max77836)
- */
- reg_data = 0x1 << CHGCTRL4_MBCICHWRCL_SHIFT;
- reg_data |= 0x5 << CHGCTRL4_MBCICHWRCH_SHIFT;
- max14577_write_reg(rmap, MAX14577_REG_CHGCTRL4, reg_data);
-
- /* End-of-Charge Current, set to 50mA (max14577) / 7.5mA (max77836) */
- reg_data = 0x0 << CHGCTRL5_EOCS_SHIFT;
- max14577_write_reg(rmap, MAX14577_REG_CHGCTRL5, reg_data);
-
/* Auto Charging Stop, default off */
reg_data = 0x0 << CHGCTRL6_AUTOSTOP_SHIFT;
max14577_write_reg(rmap, MAX14577_REG_CHGCTRL6, reg_data);

- /* Overvoltage-Protection Threshold, set to 6.5V */
- reg_data = 0x2 << CHGCTRL7_OTPCGHCVS_SHIFT;
+ ret = max14577_init_constant_voltage(chg, chg->pdata->constant_uvolt);
+ if (ret)
+ return ret;
+
+ ret = max14577_init_eoc(chg, chg->pdata->eoc_uamp);
+ if (ret)
+ return ret;
+
+ ret = max14577_init_fast_charge(chg, chg->pdata->fast_charge_uamp);
+ if (ret)
+ return ret;
+
+ /* Initialize Battery Fast-Charge Timer */
+ switch (chg->pdata->fast_charge_timer) {
+ case 5 ... 7:
+ reg_data = chg->pdata->fast_charge_timer - 3;
+ break;
+ case 0:
+ /* Disable */
+ reg_data = 0x7;
+ default:
+ dev_err(chg->dev, "Wrong value for Fast-Charge Timer: %u\n",
+ chg->pdata->fast_charge_timer);
+ return -EINVAL;
+ }
+ reg_data <<= CHGCTRL1_TCHW_SHIFT;
+ max14577_write_reg(rmap, MAX14577_REG_CHGCTRL1, reg_data);
+
+ /* Initialize Overvoltage-Protection Threshold */
+ switch (chg->pdata->ovp_uvolt) {
+ case 7500000:
+ reg_data = 0x0;
+ break;
+ case 6000000:
+ case 6500000:
+ case 7000000:
+ reg_data = 0x1 + (chg->pdata->ovp_uvolt - 6000000) / 500000;
+ break;
+ default:
+ dev_err(chg->dev, "Wrong value for OVP: %u\n",
+ chg->pdata->ovp_uvolt);
+ return -EINVAL;
+ }
+ reg_data <<= CHGCTRL7_OTPCGHCVS_SHIFT;
max14577_write_reg(rmap, MAX14577_REG_CHGCTRL7, reg_data);
+
+ return 0;
}

/* Support property from charger */
@@ -295,6 +411,66 @@ static int max14577_charger_get_property(struct power_supply *psy,
return ret;
}

+#ifdef CONFIG_OF
+static struct max14577_charger_platform_data *max14577_charger_dt_init(
+ struct platform_device *pdev)
+{
+ struct max14577_charger_platform_data *pdata;
+ struct device_node *np = pdev->dev.of_node;
+ int ret;
+
+ if (!np) {
+ dev_err(&pdev->dev, "No charger OF node\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return ERR_PTR(-ENOMEM);
+
+ ret = of_property_read_u32(np, "maxim,fast-charge-timer",
+ &pdata->fast_charge_timer);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot parse maxim,fast-charge-timer field from DT\n");
+ return ERR_PTR(ret);
+ }
+
+ ret = of_property_read_u32(np, "maxim,constant-uvolt",
+ &pdata->constant_uvolt);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot parse maxim,constant-uvolt field from DT\n");
+ return ERR_PTR(ret);
+ }
+
+ ret = of_property_read_u32(np, "maxim,fast-charge-uamp",
+ &pdata->fast_charge_uamp);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot parse maxim,fast-charge-uamp field from DT\n");
+ return ERR_PTR(ret);
+ }
+
+ ret = of_property_read_u32(np, "maxim,eoc-uamp", &pdata->eoc_uamp);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot parse maxim,eoc-uamp field from DT\n");
+ return ERR_PTR(ret);
+ }
+
+ ret = of_property_read_u32(np, "maxim,ovp-uvolt", &pdata->ovp_uvolt);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot parse maxim,ovp-uvolt field from DT\n");
+ return ERR_PTR(ret);
+ }
+
+ return pdata;
+}
+#else /* CONFIG_OF */
+static struct max14577_charger_platform_data *max14577_charger_dt_init(
+ struct platform_device *pdev)
+{
+ return NULL;
+}
+#endif /* CONFIG_OF */
+
static int max14577_charger_probe(struct platform_device *pdev)
{
struct max14577_charger *chg;
@@ -309,7 +485,13 @@ static int max14577_charger_probe(struct platform_device *pdev)
chg->dev = &pdev->dev;
chg->max14577 = max14577;

- max14577_charger_reg_init(chg);
+ chg->pdata = max14577_charger_dt_init(pdev);
+ if (IS_ERR_OR_NULL(chg->pdata))
+ return PTR_ERR(chg->pdata);
+
+ ret = max14577_charger_reg_init(chg);
+ if (ret)
+ return ret;

chg->charger.name = "max14577-charger",
chg->charger.type = POWER_SUPPLY_TYPE_BATTERY,
@@ -323,6 +505,10 @@ static int max14577_charger_probe(struct platform_device *pdev)
return ret;
}

+ /* Check for valid values for charger */
+ BUILD_BUG_ON(MAX14577_CHARGER_EOC_CURRENT_LIMIT_MIN +
+ MAX14577_CHARGER_EOC_CURRENT_LIMIT_STEP * 0xf !=
+ MAX14577_CHARGER_EOC_CURRENT_LIMIT_MAX);
return 0;
}

diff --git a/include/linux/mfd/max14577-private.h b/include/linux/mfd/max14577-private.h
index 7d514839c764..5c842f3b6da5 100644
--- a/include/linux/mfd/max14577-private.h
+++ b/include/linux/mfd/max14577-private.h
@@ -293,6 +293,22 @@ enum max14577_charger_reg {
#define MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP 25000U
#define MAX77836_CHARGER_CURRENT_LIMIT_MAX 475000U

+/*
+ * MAX14577 charger End-Of-Charge current limits
+ * (as in CHGCTRL5 register), uA
+ */
+#define MAX14577_CHARGER_EOC_CURRENT_LIMIT_MIN 50000U
+#define MAX14577_CHARGER_EOC_CURRENT_LIMIT_STEP 10000U
+#define MAX14577_CHARGER_EOC_CURRENT_LIMIT_MAX 200000U
+
+/*
+ * MAX14577/MAX77836 Battery Constant Voltage
+ * (as in CHGCTRL3 register), uV
+ */
+#define MAXIM_CHARGER_CONSTANT_VOLTAGE_MIN 4000000U
+#define MAXIM_CHARGER_CONSTANT_VOLTAGE_STEP 20000U
+#define MAXIM_CHARGER_CONSTANT_VOLTAGE_MAX 4350000U
+
/* 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 3c098d57b1d1..f31affb2385f 100644
--- a/include/linux/mfd/max14577.h
+++ b/include/linux/mfd/max14577.h
@@ -54,6 +54,14 @@ struct max14577_regulator_platform_data {
struct device_node *of_node;
};

+struct max14577_charger_platform_data {
+ u32 fast_charge_timer;
+ u32 constant_uvolt;
+ u32 fast_charge_uamp;
+ u32 eoc_uamp;
+ u32 ovp_uvolt;
+};
+
/*
* MAX14577 MFD platform data
*/
--
1.9.1

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