mfd: AXP20x: Add mfd driver for AXP20x PMIC

This patch introduces the preliminary support for PMICs X-Powers AXP202
and AXP209. The AXP209 and AXP202 are the PMUs (Power Management Unit)
used by A10, A13 and A20 SoCs and developed by X-Powers, a sister company
of Allwinner.

The core enables support for two subsystems:
- PEK (Power Enable Key)
- Regulators

Signed-off-by: Carlo Caione <carlo@caione.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

4 files changed, 451 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index e166d7176d7a..c681741ce492 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -67,6 +67,18 @@ config MFD_BCM590XX
         help
           Support for the BCM590xx PMUs from Broadcom
 
+config MFD_AXP20X
+        bool "X-Powers AXP20X"
+        select MFD_CORE
+        select REGMAP_I2C
+        select REGMAP_IRQ
+        depends on I2C=y
+        help
+          If you say Y here you get support for the X-Powers AXP202 and AXP209.
+          This driver include only the core APIs. You have to select individual
+          components like regulators or the PEK (Power Enable Key) under the
+          corresponding menus.
+
 config MFD_CROS_EC
         tristate "ChromeOS Embedded Controller"
         select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 2851275e2656..1efecf2793ae 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -102,6 +102,7 @@ obj-$(CONFIG_PMIC_DA9052)	+= da9052-irq.o
 obj-$(CONFIG_PMIC_DA9052)       += da9052-core.o
 obj-$(CONFIG_MFD_DA9052_SPI)    += da9052-spi.o
 obj-$(CONFIG_MFD_DA9052_I2C)    += da9052-i2c.o
+obj-$(CONFIG_MFD_AXP20X)        += axp20x.o
 
 obj-$(CONFIG_MFD_LP3943)        += lp3943.o
 obj-$(CONFIG_MFD_LP8788)        += lp8788.o lp8788-irq.o
diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
new file mode 100644
index 000000000000..dee653989e3a
--- /dev/null
+++ b/drivers/mfd/axp20x.c
@@ -0,0 +1,258 @@
+/*
+ * axp20x.c - MFD core driver for the X-Powers AXP202 and AXP209
+ *
+ * AXP20x comprises an adaptive USB-Compatible PWM charger, 2 BUCK DC-DC
+ * converters, 5 LDOs, multiple 12-bit ADCs of voltage, current and temperature
+ * as well as 4 configurable GPIOs.
+ *
+ * Author: Carlo Caione <carlo@caione.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/regulator/consumer.h>
+#include <linux/mfd/axp20x.h>
+#include <linux/mfd/core.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+
+#define AXP20X_OFF      0x80
+
+static const struct regmap_range axp20x_writeable_ranges[] = {
+        regmap_reg_range(AXP20X_DATACACHE(0), AXP20X_IRQ5_STATE),
+        regmap_reg_range(AXP20X_DCDC_MODE, AXP20X_FG_RES),
+};
+
+static const struct regmap_range axp20x_volatile_ranges[] = {
+        regmap_reg_range(AXP20X_IRQ1_EN, AXP20X_IRQ5_STATE),
+};
+
+static const struct regmap_access_table axp20x_writeable_table = {
+        .yes_ranges     = axp20x_writeable_ranges,
+        .n_yes_ranges   = ARRAY_SIZE(axp20x_writeable_ranges),
+};
+
+static const struct regmap_access_table axp20x_volatile_table = {
+        .yes_ranges     = axp20x_volatile_ranges,
+        .n_yes_ranges   = ARRAY_SIZE(axp20x_volatile_ranges),
+};
+
+static struct resource axp20x_pek_resources[] = {
+        {
+                .name   = "PEK_DBR",
+                .start  = AXP20X_IRQ_PEK_RIS_EDGE,
+                .end    = AXP20X_IRQ_PEK_RIS_EDGE,
+                .flags  = IORESOURCE_IRQ,
+        }, {
+                .name   = "PEK_DBF",
+                .start  = AXP20X_IRQ_PEK_FAL_EDGE,
+                .end    = AXP20X_IRQ_PEK_FAL_EDGE,
+                .flags  = IORESOURCE_IRQ,
+        },
+};
+
+static const struct regmap_config axp20x_regmap_config = {
+        .reg_bits       = 8,
+        .val_bits       = 8,
+        .wr_table       = &axp20x_writeable_table,
+        .volatile_table = &axp20x_volatile_table,
+        .max_register   = AXP20X_FG_RES,
+        .cache_type     = REGCACHE_RBTREE,
+};
+
+#define AXP20X_IRQ(_irq, _off, _mask) \
+        [AXP20X_IRQ_##_irq] = { .reg_offset = (_off), .mask = BIT(_mask) }
+
+static const struct regmap_irq axp20x_regmap_irqs[] = {
+        AXP20X_IRQ(ACIN_OVER_V,         0, 7),
+        AXP20X_IRQ(ACIN_PLUGIN,         0, 6),
+        AXP20X_IRQ(ACIN_REMOVAL,        0, 5),
+        AXP20X_IRQ(VBUS_OVER_V,         0, 4),
+        AXP20X_IRQ(VBUS_PLUGIN,         0, 3),
+        AXP20X_IRQ(VBUS_REMOVAL,        0, 2),
+        AXP20X_IRQ(VBUS_V_LOW,          0, 1),
+        AXP20X_IRQ(BATT_PLUGIN,         1, 7),
+        AXP20X_IRQ(BATT_REMOVAL,        1, 6),
+        AXP20X_IRQ(BATT_ENT_ACT_MODE,   1, 5),
+        AXP20X_IRQ(BATT_EXIT_ACT_MODE,  1, 4),
+        AXP20X_IRQ(CHARG,               1, 3),
+        AXP20X_IRQ(CHARG_DONE,          1, 2),
+        AXP20X_IRQ(BATT_TEMP_HIGH,      1, 1),
+        AXP20X_IRQ(BATT_TEMP_LOW,       1, 0),
+        AXP20X_IRQ(DIE_TEMP_HIGH,       2, 7),
+        AXP20X_IRQ(CHARG_I_LOW,         2, 6),
+        AXP20X_IRQ(DCDC1_V_LONG,        2, 5),
+        AXP20X_IRQ(DCDC2_V_LONG,        2, 4),
+        AXP20X_IRQ(DCDC3_V_LONG,        2, 3),
+        AXP20X_IRQ(PEK_SHORT,           2, 1),
+        AXP20X_IRQ(PEK_LONG,            2, 0),
+        AXP20X_IRQ(N_OE_PWR_ON,         3, 7),
+        AXP20X_IRQ(N_OE_PWR_OFF,        3, 6),
+        AXP20X_IRQ(VBUS_VALID,          3, 5),
+        AXP20X_IRQ(VBUS_NOT_VALID,      3, 4),
+        AXP20X_IRQ(VBUS_SESS_VALID,     3, 3),
+        AXP20X_IRQ(VBUS_SESS_END,       3, 2),
+        AXP20X_IRQ(LOW_PWR_LVL1,        3, 1),
+        AXP20X_IRQ(LOW_PWR_LVL2,        3, 0),
+        AXP20X_IRQ(TIMER,               4, 7),
+        AXP20X_IRQ(PEK_RIS_EDGE,        4, 6),
+        AXP20X_IRQ(PEK_FAL_EDGE,        4, 5),
+        AXP20X_IRQ(GPIO3_INPUT,         4, 3),
+        AXP20X_IRQ(GPIO2_INPUT,         4, 2),
+        AXP20X_IRQ(GPIO1_INPUT,         4, 1),
+        AXP20X_IRQ(GPIO0_INPUT,         4, 0),
+};
+
+static const struct of_device_id axp20x_of_match[] = {
+        { .compatible = "x-powers,axp202", .data = (void *) AXP202_ID },
+        { .compatible = "x-powers,axp209", .data = (void *) AXP209_ID },
+        { },
+};
+MODULE_DEVICE_TABLE(of, axp20x_of_match);
+
+/*
+ * This is useless for OF-enabled devices, but it is needed by I2C subsystem
+ */
+static const struct i2c_device_id axp20x_i2c_id[] = {
+        { },
+};
+MODULE_DEVICE_TABLE(i2c, axp20x_i2c_id);
+
+static const struct regmap_irq_chip axp20x_regmap_irq_chip = {
+        .name                   = "axp20x_irq_chip",
+        .status_base            = AXP20X_IRQ1_STATE,
+        .ack_base               = AXP20X_IRQ1_STATE,
+        .mask_base              = AXP20X_IRQ1_EN,
+        .num_regs               = 5,
+        .irqs                   = axp20x_regmap_irqs,
+        .num_irqs               = ARRAY_SIZE(axp20x_regmap_irqs),
+        .mask_invert            = true,
+        .init_ack_masked        = true,
+};
+
+static const char * const axp20x_supplies[] = {
+        "acin",
+        "vin2",
+        "vin3",
+        "ldo24in",
+        "ldo3in",
+        "ldo5in",
+};
+
+static struct mfd_cell axp20x_cells[] = {
+        {
+                .name                   = "axp20x-pek",
+                .num_resources          = ARRAY_SIZE(axp20x_pek_resources),
+                .resources              = axp20x_pek_resources,
+        }, {
+                .name                   = "axp20x-regulator",
+                .parent_supplies        = axp20x_supplies,
+                .num_parent_supplies    = ARRAY_SIZE(axp20x_supplies),
+        },
+};
+
+static struct axp20x_dev *axp20x_pm_power_off;
+static void axp20x_power_off(void)
+{
+        regmap_write(axp20x_pm_power_off->regmap, AXP20X_OFF_CTRL,
+                     AXP20X_OFF);
+}
+
+static int axp20x_i2c_probe(struct i2c_client *i2c,
+                         const struct i2c_device_id *id)
+{
+        struct axp20x_dev *axp20x;
+        const struct of_device_id *of_id;
+        int ret;
+
+        axp20x = devm_kzalloc(&i2c->dev, sizeof(*axp20x), GFP_KERNEL);
+        if (!axp20x)
+                return -ENOMEM;
+
+        of_id = of_match_device(axp20x_of_match, &i2c->dev);
+        if (!of_id) {
+                dev_err(&i2c->dev, "Unable to setup AXP20X data\n");
+                return -ENODEV;
+        }
+        axp20x->variant = (long) of_id->data;
+
+        axp20x->i2c_client = i2c;
+        axp20x->dev = &i2c->dev;
+        dev_set_drvdata(axp20x->dev, axp20x);
+
+        axp20x->regmap = devm_regmap_init_i2c(i2c, &axp20x_regmap_config);
+        if (IS_ERR(axp20x->regmap)) {
+                ret = PTR_ERR(axp20x->regmap);
+                dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
+                return ret;
+        }
+
+        ret = regmap_add_irq_chip(axp20x->regmap, i2c->irq,
+                                  IRQF_ONESHOT | IRQF_SHARED, -1,
+                                  &axp20x_regmap_irq_chip,
+                                  &axp20x->regmap_irqc);
+        if (ret) {
+                dev_err(&i2c->dev, "failed to add irq chip: %d\n", ret);
+                return ret;
+        }
+
+        ret = mfd_add_devices(axp20x->dev, -1, axp20x_cells,
+                              ARRAY_SIZE(axp20x_cells), NULL, 0, NULL);
+
+        if (ret) {
+                dev_err(&i2c->dev, "failed to add MFD devices: %d\n", ret);
+                regmap_del_irq_chip(i2c->irq, axp20x->regmap_irqc);
+                return ret;
+        }
+
+        if (!pm_power_off) {
+                axp20x_pm_power_off = axp20x;
+                pm_power_off = axp20x_power_off;
+        }
+
+        dev_info(&i2c->dev, "AXP20X driver loaded\n");
+
+        return 0;
+}
+
+static int axp20x_i2c_remove(struct i2c_client *i2c)
+{
+        struct axp20x_dev *axp20x = i2c_get_clientdata(i2c);
+
+        if (axp20x == axp20x_pm_power_off) {
+                axp20x_pm_power_off = NULL;
+                pm_power_off = NULL;
+        }
+
+        mfd_remove_devices(axp20x->dev);
+        regmap_del_irq_chip(axp20x->i2c_client->irq, axp20x->regmap_irqc);
+
+        return 0;
+}
+
+static struct i2c_driver axp20x_i2c_driver = {
+        .driver = {
+                .name   = "axp20x",
+                .owner  = THIS_MODULE,
+                .of_match_table = of_match_ptr(axp20x_of_match),
+        },
+        .probe          = axp20x_i2c_probe,
+        .remove         = axp20x_i2c_remove,
+        .id_table       = axp20x_i2c_id,
+};
+
+module_i2c_driver(axp20x_i2c_driver);
+
+MODULE_DESCRIPTION("PMIC MFD core driver for AXP20X");
+MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/axp20x.h b/include/linux/mfd/axp20x.h
new file mode 100644
index 000000000000..d0e31a2287ac
--- /dev/null
+++ b/include/linux/mfd/axp20x.h
@@ -0,0 +1,180 @@
+/*
+ * Functions and registers to access AXP20X power management chip.
+ *
+ * Copyright (C) 2013, Carlo Caione <carlo@caione.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __LINUX_MFD_AXP20X_H
+#define __LINUX_MFD_AXP20X_H
+
+enum {
+        AXP202_ID = 0,
+        AXP209_ID,
+};
+
+#define AXP20X_DATACACHE(m)             (0x04 + (m))
+
+/* Power supply */
+#define AXP20X_PWR_INPUT_STATUS         0x00
+#define AXP20X_PWR_OP_MODE              0x01
+#define AXP20X_USB_OTG_STATUS           0x02
+#define AXP20X_PWR_OUT_CTRL             0x12
+#define AXP20X_DCDC2_V_OUT              0x23
+#define AXP20X_DCDC2_LDO3_V_SCAL        0x25
+#define AXP20X_DCDC3_V_OUT              0x27
+#define AXP20X_LDO24_V_OUT              0x28
+#define AXP20X_LDO3_V_OUT               0x29
+#define AXP20X_VBUS_IPSOUT_MGMT         0x30
+#define AXP20X_V_OFF                    0x31
+#define AXP20X_OFF_CTRL                 0x32
+#define AXP20X_CHRG_CTRL1               0x33
+#define AXP20X_CHRG_CTRL2               0x34
+#define AXP20X_CHRG_BAK_CTRL            0x35
+#define AXP20X_PEK_KEY                  0x36
+#define AXP20X_DCDC_FREQ                0x37
+#define AXP20X_V_LTF_CHRG               0x38
+#define AXP20X_V_HTF_CHRG               0x39
+#define AXP20X_APS_WARN_L1              0x3a
+#define AXP20X_APS_WARN_L2              0x3b
+#define AXP20X_V_LTF_DISCHRG            0x3c
+#define AXP20X_V_HTF_DISCHRG            0x3d
+
+/* Interrupt */
+#define AXP20X_IRQ1_EN                  0x40
+#define AXP20X_IRQ2_EN                  0x41
+#define AXP20X_IRQ3_EN                  0x42
+#define AXP20X_IRQ4_EN                  0x43
+#define AXP20X_IRQ5_EN                  0x44
+#define AXP20X_IRQ1_STATE               0x48
+#define AXP20X_IRQ2_STATE               0x49
+#define AXP20X_IRQ3_STATE               0x4a
+#define AXP20X_IRQ4_STATE               0x4b
+#define AXP20X_IRQ5_STATE               0x4c
+
+/* ADC */
+#define AXP20X_ACIN_V_ADC_H             0x56
+#define AXP20X_ACIN_V_ADC_L             0x57
+#define AXP20X_ACIN_I_ADC_H             0x58
+#define AXP20X_ACIN_I_ADC_L             0x59
+#define AXP20X_VBUS_V_ADC_H             0x5a
+#define AXP20X_VBUS_V_ADC_L             0x5b
+#define AXP20X_VBUS_I_ADC_H             0x5c
+#define AXP20X_VBUS_I_ADC_L             0x5d
+#define AXP20X_TEMP_ADC_H               0x5e
+#define AXP20X_TEMP_ADC_L               0x5f
+#define AXP20X_TS_IN_H                  0x62
+#define AXP20X_TS_IN_L                  0x63
+#define AXP20X_GPIO0_V_ADC_H            0x64
+#define AXP20X_GPIO0_V_ADC_L            0x65
+#define AXP20X_GPIO1_V_ADC_H            0x66
+#define AXP20X_GPIO1_V_ADC_L            0x67
+#define AXP20X_PWR_BATT_H               0x70
+#define AXP20X_PWR_BATT_M               0x71
+#define AXP20X_PWR_BATT_L               0x72
+#define AXP20X_BATT_V_H                 0x78
+#define AXP20X_BATT_V_L                 0x79
+#define AXP20X_BATT_CHRG_I_H            0x7a
+#define AXP20X_BATT_CHRG_I_L            0x7b
+#define AXP20X_BATT_DISCHRG_I_H         0x7c
+#define AXP20X_BATT_DISCHRG_I_L         0x7d
+#define AXP20X_IPSOUT_V_HIGH_H          0x7e
+#define AXP20X_IPSOUT_V_HIGH_L          0x7f
+
+/* Power supply */
+#define AXP20X_DCDC_MODE                0x80
+#define AXP20X_ADC_EN1                  0x82
+#define AXP20X_ADC_EN2                  0x83
+#define AXP20X_ADC_RATE                 0x84
+#define AXP20X_GPIO10_IN_RANGE          0x85
+#define AXP20X_GPIO1_ADC_IRQ_RIS        0x86
+#define AXP20X_GPIO1_ADC_IRQ_FAL        0x87
+#define AXP20X_TIMER_CTRL               0x8a
+#define AXP20X_VBUS_MON                 0x8b
+#define AXP20X_OVER_TMP                 0x8f
+
+/* GPIO */
+#define AXP20X_GPIO0_CTRL               0x90
+#define AXP20X_LDO5_V_OUT               0x91
+#define AXP20X_GPIO1_CTRL               0x92
+#define AXP20X_GPIO2_CTRL               0x93
+#define AXP20X_GPIO20_SS                0x94
+#define AXP20X_GPIO3_CTRL               0x95
+
+/* Battery */
+#define AXP20X_CHRG_CC_31_24            0xb0
+#define AXP20X_CHRG_CC_23_16            0xb1
+#define AXP20X_CHRG_CC_15_8             0xb2
+#define AXP20X_CHRG_CC_7_0              0xb3
+#define AXP20X_DISCHRG_CC_31_24         0xb4
+#define AXP20X_DISCHRG_CC_23_16         0xb5
+#define AXP20X_DISCHRG_CC_15_8          0xb6
+#define AXP20X_DISCHRG_CC_7_0           0xb7
+#define AXP20X_CC_CTRL                  0xb8
+#define AXP20X_FG_RES                   0xb9
+
+/* Regulators IDs */
+enum {
+        AXP20X_LDO1 = 0,
+        AXP20X_LDO2,
+        AXP20X_LDO3,
+        AXP20X_LDO4,
+        AXP20X_LDO5,
+        AXP20X_DCDC2,
+        AXP20X_DCDC3,
+        AXP20X_REG_ID_MAX,
+};
+
+/* IRQs */
+enum {
+        AXP20X_IRQ_ACIN_OVER_V = 1,
+        AXP20X_IRQ_ACIN_PLUGIN,
+        AXP20X_IRQ_ACIN_REMOVAL,
+        AXP20X_IRQ_VBUS_OVER_V,
+        AXP20X_IRQ_VBUS_PLUGIN,
+        AXP20X_IRQ_VBUS_REMOVAL,
+        AXP20X_IRQ_VBUS_V_LOW,
+        AXP20X_IRQ_BATT_PLUGIN,
+        AXP20X_IRQ_BATT_REMOVAL,
+        AXP20X_IRQ_BATT_ENT_ACT_MODE,
+        AXP20X_IRQ_BATT_EXIT_ACT_MODE,
+        AXP20X_IRQ_CHARG,
+        AXP20X_IRQ_CHARG_DONE,
+        AXP20X_IRQ_BATT_TEMP_HIGH,
+        AXP20X_IRQ_BATT_TEMP_LOW,
+        AXP20X_IRQ_DIE_TEMP_HIGH,
+        AXP20X_IRQ_CHARG_I_LOW,
+        AXP20X_IRQ_DCDC1_V_LONG,
+        AXP20X_IRQ_DCDC2_V_LONG,
+        AXP20X_IRQ_DCDC3_V_LONG,
+        AXP20X_IRQ_PEK_SHORT = 22,
+        AXP20X_IRQ_PEK_LONG,
+        AXP20X_IRQ_N_OE_PWR_ON,
+        AXP20X_IRQ_N_OE_PWR_OFF,
+        AXP20X_IRQ_VBUS_VALID,
+        AXP20X_IRQ_VBUS_NOT_VALID,
+        AXP20X_IRQ_VBUS_SESS_VALID,
+        AXP20X_IRQ_VBUS_SESS_END,
+        AXP20X_IRQ_LOW_PWR_LVL1,
+        AXP20X_IRQ_LOW_PWR_LVL2,
+        AXP20X_IRQ_TIMER,
+        AXP20X_IRQ_PEK_RIS_EDGE,
+        AXP20X_IRQ_PEK_FAL_EDGE,
+        AXP20X_IRQ_GPIO3_INPUT,
+        AXP20X_IRQ_GPIO2_INPUT,
+        AXP20X_IRQ_GPIO1_INPUT,
+        AXP20X_IRQ_GPIO0_INPUT,
+};
+
+struct axp20x_dev {
+        struct device                   *dev;
+        struct i2c_client               *i2c_client;
+        struct regmap                   *regmap;
+        struct regmap_irq_chip_data     *regmap_irqc;
+        long                            variant;
+};
+
+#endif /* __LINUX_MFD_AXP20X_H */