[PATCH v4 3/3] mfd: max8998: Add support for Device Tree

From: Tomasz Figa
Date: Tue Jun 25 2013 - 09:46:55 EST

This patch adds Device Tree support to max8998 driver.

Signed-off-by: Tomasz Figa <t.figa@xxxxxxxxxxx>
---
Documentation/devicetree/bindings/mfd/max8998.txt | 119 ++++++++++++++++++++
drivers/mfd/max8998.c | 67 ++++++++++-
drivers/regulator/max8998.c | 130 +++++++++++++++++++++-
drivers/rtc/rtc-max8998.c | 2 +-
include/linux/mfd/max8998-private.h | 2 +
include/linux/mfd/max8998.h | 2 +
6 files changed, 315 insertions(+), 7 deletions(-)
create mode 100644 Documentation/devicetree/bindings/mfd/max8998.txt

Changes since v3:
- Addressed Sachin's comments:
- fixed typos in documentation
- removed redundant error messages
- and other minor stylistic fixes
- Reworded parts of the documentation and improved formatting a bit
- Simplified device tree parsing code even more
- Replaced most of #ifdef CONFIG_OF with if (IS_ENABLED(CONFIG_OF))
to move responsibility of dropping unused code to compiler and avoid
unnecessary function stubs

diff --git a/Documentation/devicetree/bindings/mfd/max8998.txt b/Documentation/devicetree/bindings/mfd/max8998.txt
new file mode 100644
index 0000000..23a3650
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/max8998.txt
@@ -0,0 +1,119 @@
+* Maxim MAX8998, National/TI LP3974 multi-function device
+
+The Maxim MAX8998 is a multi-function device which includes voltage/current
+regulators, real time clock, battery charging controller and several
+other sub-blocks. It is interfaced using an I2C interface. Each sub-block
+is addressed by the host system using different i2c slave address.
+
+PMIC sub-block
+--------------
+
+The PMIC sub-block contains a number of voltage and current regulators,
+with controllable parameters and dynamic voltage scaling capability.
+In addition, it includes a real time clock and battery charging controller
+as well. It is accessible at I2C address 0x66.
+
+Required properties:
+- compatible: Should be one of the following:
+ - "maxim,max8998" for Maxim MAX8998
+ - "national,lp3974" or "ti,lp3974" for National/TI LP3974.
+- reg: Specifies the i2c slave address of the pmic block. It should be 0x66.
+
+Optional properties:
+- interrupt-parent: Specifies the phandle of the interrupt controller to which
+ the interrupts from MAX8998 are routed to.
+- interrupts: Interrupt specifiers for two interrupt sources.
+ - First interrupt specifier is for main interrupt.
+ - Second interrupt specifier is for power-on/-off interrupt.
+- max8998,pmic-buck1-dvs-gpios: GPIO specifiers for two host gpios used
+ for buck 1 dvs. The format of the gpio specifier depends on the gpio
+ controller.
+- max8998,pmic-buck2-dvs-gpio: GPIO specifier for host gpio used
+ for buck 2 dvs. The format of the gpio specifier depends on the gpio
+ controller.
+- max8998,pmic-buck1-default-dvs-idx: Default voltage setting selected from
+ the possible 4 options selectable by the dvs gpios. The value of this
+ property should be 0, 1, 2 or 3. If not specified or out of range,
+ a default value of 0 is taken.
+- max8998,pmic-buck2-default-dvs-idx: Default voltage setting selected from
+ the possible 2 options selectable by the dvs gpios. The value of this
+ property should be 0 or 1. If not specified or out of range, a default
+ value of 0 is taken.
+- max8998,pmic-buck-voltage-lock: If present, disallows changing of
+ preprogrammed buck dvfs voltages.
+
+Additional properties required if max8998,pmic-buck1-dvs-gpios is defined:
+- max8998,pmic-buck1-dvs-voltage: An array of 4 voltage values in microvolts
+ for buck1 regulator that can be selected using dvs gpio.
+
+Additional properties required if max8998,pmic-buck2-dvs-gpio is defined:
+- max8998,pmic-buck2-dvs-voltage: An array of 2 voltage values in microvolts
+ for buck2 regulator that can be selected using dvs gpio.
+
+Regulators: All the regulators of MAX8998 to be instantiated shall be
+listed in a child node named 'regulators'. Each regulator is represented
+by a child node of the 'regulators' node.
+
+ regulator-name {
+ /* standard regulator bindings here */
+ };
+
+Following regulators of the MAX8998 PMIC block are supported. Note that
+the 'n' in regulator name, as in LDOn or BUCKn, represents the LDO or BUCK
+number as described in MAX8998 datasheet.
+
+ - LDOn
+ - valid values for n are 2 to 17
+ - Example: LDO2, LDO10, LDO17
+ - BUCKn
+ - valid values for n are 1 to 4.
+ - Example: BUCK1, BUCK2, BUCK3, BUCK4
+
+ - ENVICHG: Battery Charging Current Monitor Output. This is a fixed
+ voltage type regulator
+
+ - ESAFEOUT1: (ldo19)
+ - ESAFEOUT2: (ld020)
+
+Standard regulator bindings are used inside regulator subnodes. Check
+ Documentation/devicetree/bindings/regulator/regulator.txt
+for more details.
+
+Example:
+
+ pmic@66 {
+ compatible = "maxim,max8998-pmic";
+ reg = <0x66>;
+ interrupt-parent = <&wakeup_eint>;
+ interrupts = <4 0>, <3 0>;
+
+ /* Buck 1 DVS settings */
+ max8998,pmic-buck1-default-dvs-idx = <0>;
+ max8998,pmic-buck1-dvs-gpios = <&gpx0 0 1 0 0>, /* SET1 */
+ <&gpx0 1 1 0 0>; /* SET2 */
+ max8998,pmic-buck1-dvs-voltage = <1350000>, <1300000>,
+ <1000000>, <950000>;
+
+ /* Buck 2 DVS settings */
+ max8998,pmic-buck2-default-dvs-idx = <0>;
+ max8998,pmic-buck2-dvs-gpio = <&gpx0 0 3 0 0>; /* SET3 */
+ max8998,pmic-buck2-dvs-voltage = <1350000>, <1300000>;
+
+ /* Regulators to instantiate */
+ regulators {
+ ldo2_reg: LDO2 {
+ regulator-name = "VDD_ALIVE_1.1V";
+ regulator-min-microvolt = <1100000>;
+ regulator-max-microvolt = <1100000>;
+ regulator-always-on;
+ };
+
+ buck1_reg: BUCK1 {
+ regulator-name = "VDD_ARM_1.2V";
+ regulator-min-microvolt = <950000>;
+ regulator-max-microvolt = <1350000>;
+ regulator-always-on;
+ regulator-boot-on;
+ };
+ };
+ };
diff --git a/drivers/mfd/max8998.c b/drivers/mfd/max8998.c
index d7218cc..21af51a 100644
--- a/drivers/mfd/max8998.c
+++ b/drivers/mfd/max8998.c
@@ -20,12 +20,15 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/

+#include <linux/err.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
#include <linux/pm_runtime.h>
#include <linux/mutex.h>
#include <linux/mfd/core.h>
@@ -128,6 +131,56 @@ int max8998_update_reg(struct i2c_client *i2c, u8 reg, u8 val, u8 mask)
}
EXPORT_SYMBOL(max8998_update_reg);

+#ifdef CONFIG_OF
+static struct of_device_id max8998_dt_match[] = {
+ { .compatible = "maxim,max8998", .data = (void *)TYPE_MAX8998 },
+ { .compatible = "national,lp3974", .data = (void *)TYPE_LP3974 },
+ { .compatible = "ti,lp3974", .data = (void *)TYPE_LP3974 },
+ {},
+};
+MODULE_DEVICE_TABLE(of, max8998_dt_match);
+#endif
+
+/*
+ * Only the common platform data elements for max8998 are parsed here from the
+ * device tree. Other sub-modules of max8998 such as pmic, rtc and others have
+ * to parse their own platform data elements from device tree.
+ *
+ * The max8998 platform data structure is instantiated here and the drivers for
+ * the sub-modules need not instantiate another instance while parsing their
+ * platform data.
+ */
+static struct max8998_platform_data *max8998_i2c_parse_dt_pdata(
+ struct device *dev)
+{
+ struct max8998_platform_data *pd;
+
+ pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
+ if (!pd)
+ return ERR_PTR(-ENOMEM);
+
+ pd->ono = irq_of_parse_and_map(dev->of_node, 1);
+
+ /*
+ * ToDo: the 'wakeup' member in the platform data is more of a linux
+ * specfic information. Hence, there is no binding for that yet and
+ * not parsed here.
+ */
+ return pd;
+}
+
+static inline int max8998_i2c_get_driver_data(struct i2c_client *i2c,
+ const struct i2c_device_id *id)
+{
+ if (IS_ENABLED(CONFIG_OF) && i2c->dev.of_node) {
+ const struct of_device_id *match;
+ match = of_match_node(max8998_dt_match, i2c->dev.of_node);
+ return (int)match->data;
+ }
+
+ return (int)id->driver_data;
+}
+
static int max8998_i2c_probe(struct i2c_client *i2c,
const struct i2c_device_id *id)
{
@@ -139,11 +192,20 @@ static int max8998_i2c_probe(struct i2c_client *i2c,
if (max8998 == NULL)
return -ENOMEM;

+ if (IS_ENABLED(CONFIG_OF) && i2c->dev.of_node) {
+ pdata = max8998_i2c_parse_dt_pdata(&i2c->dev);
+ if (IS_ERR(pdata)) {
+ ret = PTR_ERR(pdata);
+ goto err;
+ }
+ }
+
i2c_set_clientdata(i2c, max8998);
max8998->dev = &i2c->dev;
max8998->i2c = i2c;
max8998->irq = i2c->irq;
- max8998->type = id->driver_data;
+ max8998->type = max8998_i2c_get_driver_data(i2c, id);
+ max8998->pdata = pdata;
if (pdata) {
max8998->ono = pdata->ono;
max8998->irq_base = pdata->irq_base;
@@ -158,7 +220,7 @@ static int max8998_i2c_probe(struct i2c_client *i2c,

pm_runtime_set_active(max8998->dev);

- switch (id->driver_data) {
+ switch (max8998->type) {
case TYPE_LP3974:
ret = mfd_add_devices(max8998->dev, -1,
lp3974_devs, ARRAY_SIZE(lp3974_devs),
@@ -314,6 +376,7 @@ static struct i2c_driver max8998_i2c_driver = {
.name = "max8998",
.owner = THIS_MODULE,
.pm = &max8998_pm,
+ .of_match_table = of_match_ptr(max8998_dt_match),
},
.probe = max8998_i2c_probe,
.remove = max8998_i2c_remove,
diff --git a/drivers/regulator/max8998.c b/drivers/regulator/max8998.c
index 8c45b93..e87bc80 100644
--- a/drivers/regulator/max8998.c
+++ b/drivers/regulator/max8998.c
@@ -28,8 +28,11 @@
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
#include <linux/mfd/max8998.h>
#include <linux/mfd/max8998-private.h>

@@ -589,13 +592,13 @@ static struct regulator_desc regulators[] = {
.type = REGULATOR_VOLTAGE,
.owner = THIS_MODULE,
}, {
- .name = "EN32KHz AP",
+ .name = "EN32KHz-AP",
.id = MAX8998_EN32KHZ_AP,
.ops = &max8998_others_ops,
.type = REGULATOR_VOLTAGE,
.owner = THIS_MODULE,
}, {
- .name = "EN32KHz CP",
+ .name = "EN32KHz-CP",
.id = MAX8998_EN32KHZ_CP,
.ops = &max8998_others_ops,
.type = REGULATOR_VOLTAGE,
@@ -621,10 +624,121 @@ static struct regulator_desc regulators[] = {
}
};

+static int max8998_pmic_dt_parse_dvs_gpio(struct max8998_dev *iodev,
+ struct max8998_platform_data *pdata,
+ struct device_node *pmic_np)
+{
+ int gpio;
+
+ gpio = of_get_named_gpio(pmic_np, "max8998,pmic-buck1-dvs-gpios", 0);
+ if (!gpio_is_valid(gpio)) {
+ dev_err(iodev->dev, "invalid buck1 gpio[0]: %d\n", gpio);
+ return -EINVAL;
+ }
+ pdata->buck1_set1 = gpio;
+
+ gpio = of_get_named_gpio(pmic_np, "max8998,pmic-buck1-dvs-gpios", 1);
+ if (!gpio_is_valid(gpio)) {
+ dev_err(iodev->dev, "invalid buck1 gpio[1]: %d\n", gpio);
+ return -EINVAL;
+ }
+ pdata->buck1_set2 = gpio;
+
+ gpio = of_get_named_gpio(pmic_np, "max8998,pmic-buck2-dvs-gpio", 0);
+ if (!gpio_is_valid(gpio)) {
+ dev_err(iodev->dev, "invalid buck 2 gpio: %d\n", gpio);
+ return -EINVAL;
+ }
+ pdata->buck2_set3 = gpio;
+
+ return 0;
+}
+
+static int max8998_pmic_dt_parse_pdata(struct max8998_dev *iodev,
+ struct max8998_platform_data *pdata)
+{
+ struct device_node *pmic_np = iodev->dev->of_node;
+ struct device_node *regulators_np, *reg_np;
+ struct max8998_regulator_data *rdata;
+ unsigned int i;
+ int ret;
+
+ regulators_np = of_get_child_by_name(pmic_np, "regulators");
+ if (!regulators_np) {
+ dev_err(iodev->dev, "could not find regulators sub-node\n");
+ return -EINVAL;
+ }
+
+ /* count the number of regulators to be supported in pmic */
+ pdata->num_regulators = of_get_child_count(regulators_np);
+
+ rdata = devm_kzalloc(iodev->dev, sizeof(*rdata) *
+ pdata->num_regulators, GFP_KERNEL);
+ if (!rdata)
+ return -ENOMEM;
+
+ pdata->regulators = rdata;
+ for (i = 0; i < ARRAY_SIZE(regulators); ++i) {
+ reg_np = of_get_child_by_name(regulators_np,
+ regulators[i].name);
+ if (!reg_np)
+ continue;
+
+ rdata->id = regulators[i].id;
+ rdata->initdata = of_get_regulator_init_data(
+ iodev->dev, reg_np);
+ rdata->reg_node = reg_np;
+ ++rdata;
+ }
+
+ ret = max8998_pmic_dt_parse_dvs_gpio(iodev, pdata, pmic_np);
+ if (ret)
+ return -EINVAL;
+
+ if (of_find_property(pmic_np, "max8998,pmic-buck-voltage-lock", NULL))
+ pdata->buck_voltage_lock = true;
+
+ ret = of_property_read_u32(pmic_np,
+ "max8998,pmic-buck1-default-dvs-idx",
+ &pdata->buck1_default_idx);
+ if (!ret && pdata->buck1_default_idx >= 4) {
+ pdata->buck1_default_idx = 0;
+ dev_warn(iodev->dev, "invalid value for default dvs index, using 0 instead\n");
+ }
+
+ ret = of_property_read_u32(pmic_np,
+ "max8998,pmic-buck2-default-dvs-idx",
+ &pdata->buck2_default_idx);
+ if (!ret && pdata->buck2_default_idx >= 2) {
+ pdata->buck2_default_idx = 0;
+ dev_warn(iodev->dev, "invalid value for default dvs index, using 0 instead\n");
+ }
+
+ ret = of_property_read_u32_array(pmic_np,
+ "max8998,pmic-buck1-dvs-voltage",
+ pdata->buck1_voltage,
+ ARRAY_SIZE(pdata->buck1_voltage));
+ if (ret) {
+ dev_err(iodev->dev, "buck1 voltages not specified\n");
+ return -EINVAL;
+ }
+
+ ret = of_property_read_u32_array(pmic_np,
+ "max8998,pmic-buck2-dvs-voltage",
+ pdata->buck2_voltage,
+ ARRAY_SIZE(pdata->buck2_voltage));
+ if (ret) {
+ dev_err(iodev->dev, "buck2 voltages not specified\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int max8998_pmic_probe(struct platform_device *pdev)
{
struct max8998_dev *iodev = dev_get_drvdata(pdev->dev.parent);
- struct max8998_platform_data *pdata = dev_get_platdata(iodev->dev);
+ struct max8998_platform_data *pdata = iodev->pdata;
struct regulator_config config = { };
struct regulator_dev **rdev;
struct max8998_data *max8998;
@@ -637,6 +751,12 @@ static int max8998_pmic_probe(struct platform_device *pdev)
return -ENODEV;
}

+ if (IS_ENABLED(CONFIG_OF) && iodev->dev->of_node) {
+ ret = max8998_pmic_dt_parse_pdata(iodev, pdata);
+ if (ret)
+ return ret;
+ }
+
max8998 = devm_kzalloc(&pdev->dev, sizeof(struct max8998_data),
GFP_KERNEL);
if (!max8998)
@@ -750,13 +870,15 @@ static int max8998_pmic_probe(struct platform_device *pdev)
}

config.dev = max8998->dev;
+ config.of_node = pdata->regulators[i].reg_node;
config.init_data = pdata->regulators[i].initdata;
config.driver_data = max8998;

rdev[i] = regulator_register(&regulators[index], &config);
if (IS_ERR(rdev[i])) {
ret = PTR_ERR(rdev[i]);
- dev_err(max8998->dev, "regulator init failed\n");
+ dev_err(max8998->dev, "regulator %s init failed (%d)\n",
+ regulators[index].name, ret);
rdev[i] = NULL;
goto err;
}
diff --git a/drivers/rtc/rtc-max8998.c b/drivers/rtc/rtc-max8998.c
index 46f2301..042a873 100644
--- a/drivers/rtc/rtc-max8998.c
+++ b/drivers/rtc/rtc-max8998.c
@@ -253,7 +253,7 @@ static const struct rtc_class_ops max8998_rtc_ops = {
static int max8998_rtc_probe(struct platform_device *pdev)
{
struct max8998_dev *max8998 = dev_get_drvdata(pdev->dev.parent);
- struct max8998_platform_data *pdata = dev_get_platdata(max8998->dev);
+ struct max8998_platform_data *pdata = max8998->pdata;
struct max8998_rtc_info *info;
int ret;

diff --git a/include/linux/mfd/max8998-private.h b/include/linux/mfd/max8998-private.h
index bfb48b6..84844e0 100644
--- a/include/linux/mfd/max8998-private.h
+++ b/include/linux/mfd/max8998-private.h
@@ -137,6 +137,7 @@ struct irq_domain;
/**
* struct max8998_dev - max8998 master device for sub-drivers
* @dev: master device of the chip (can be used to access platform data)
+ * @pdata: platform data for the driver and subdrivers
* @i2c: i2c client private data for regulator
* @rtc: i2c client private data for rtc
* @iolock: mutex for serializing io access
@@ -150,6 +151,7 @@ struct irq_domain;
*/
struct max8998_dev {
struct device *dev;
+ struct max8998_platform_data *pdata;
struct i2c_client *i2c;
struct i2c_client *rtc;
struct mutex iolock;
diff --git a/include/linux/mfd/max8998.h b/include/linux/mfd/max8998.h
index ca56bb0..e3956a6 100644
--- a/include/linux/mfd/max8998.h
+++ b/include/linux/mfd/max8998.h
@@ -58,10 +58,12 @@ enum {
* max8998_regulator_data - regulator data
* @id: regulator id
* @initdata: regulator init data (contraints, supplies, ...)
+ * @reg_node: DT node of regulator (unused on non-DT platforms)
*/
struct max8998_regulator_data {
int id;
struct regulator_init_data *initdata;
+ struct device_node *reg_node;
};

/**
--
1.8.2.1


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