mfd: Add an AS3711 PMIC MFD driver

AS3711 is a PMIC with multiple DCDC and LDO power supplies, GPIOs, an RTC,
a battery charger and a general purpose ADC. This patch adds support for
the MFD with support for a regulator driver and a backlight driver.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 227 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index f5b839b718aa..475c26696b95 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1103,6 +1103,15 @@ config MFD_RETU
           Retu is a multi-function device found on Nokia Internet Tablets
           (770, N800 and N810).
 
+config MFD_AS3711
+        bool "Support for AS3711"
+        select MFD_CORE
+        select REGMAP_I2C
+        select REGMAP_IRQ
+        depends on I2C=y
+        help
+          Support for the AS3711 PMIC from AMS
+
 endmenu
 endif
 
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 2689c8a0d781..f2216dfd963c 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -146,3 +146,4 @@ obj-$(CONFIG_MFD_SEC_CORE)	+= sec-core.o sec-irq.o
 obj-$(CONFIG_MFD_SYSCON)        += syscon.o
 obj-$(CONFIG_MFD_LM3533)        += lm3533-core.o lm3533-ctrlbank.o
 obj-$(CONFIG_MFD_RETU)          += retu-mfd.o
+obj-$(CONFIG_MFD_AS3711)        += as3711.o
diff --git a/drivers/mfd/as3711.c b/drivers/mfd/as3711.c
new file mode 100644
index 000000000000..e994c9691124
--- /dev/null
+++ b/drivers/mfd/as3711.c
@@ -0,0 +1,217 @@
+/*
+ * AS3711 PMIC MFC driver
+ *
+ * Copyright (C) 2012 Renesas Electronics Corporation
+ * Author: Guennadi Liakhovetski, <g.liakhovetski@gmx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the version 2 of the GNU General Public License as
+ * published by the Free Software Foundation
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mfd/as3711.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+enum {
+        AS3711_REGULATOR,
+        AS3711_BACKLIGHT,
+};
+
+/*
+ * Ok to have it static: it is only used during probing and multiple I2C devices
+ * cannot be probed simultaneously. Just make sure to avoid stale data.
+ */
+static struct mfd_cell as3711_subdevs[] = {
+        [AS3711_REGULATOR] = {.name = "as3711-regulator",},
+        [AS3711_BACKLIGHT] = {.name = "as3711-backlight",},
+};
+
+static bool as3711_volatile_reg(struct device *dev, unsigned int reg)
+{
+        switch (reg) {
+        case AS3711_GPIO_SIGNAL_IN:
+        case AS3711_INTERRUPT_STATUS_1:
+        case AS3711_INTERRUPT_STATUS_2:
+        case AS3711_INTERRUPT_STATUS_3:
+        case AS3711_CHARGER_STATUS_1:
+        case AS3711_CHARGER_STATUS_2:
+        case AS3711_REG_STATUS:
+                return true;
+        }
+        return false;
+}
+
+static bool as3711_precious_reg(struct device *dev, unsigned int reg)
+{
+        switch (reg) {
+        case AS3711_INTERRUPT_STATUS_1:
+        case AS3711_INTERRUPT_STATUS_2:
+        case AS3711_INTERRUPT_STATUS_3:
+                return true;
+        }
+        return false;
+}
+
+static bool as3711_readable_reg(struct device *dev, unsigned int reg)
+{
+        switch (reg) {
+        case AS3711_SD_1_VOLTAGE:
+        case AS3711_SD_2_VOLTAGE:
+        case AS3711_SD_3_VOLTAGE:
+        case AS3711_SD_4_VOLTAGE:
+        case AS3711_LDO_1_VOLTAGE:
+        case AS3711_LDO_2_VOLTAGE:
+        case AS3711_LDO_3_VOLTAGE:
+        case AS3711_LDO_4_VOLTAGE:
+        case AS3711_LDO_5_VOLTAGE:
+        case AS3711_LDO_6_VOLTAGE:
+        case AS3711_LDO_7_VOLTAGE:
+        case AS3711_LDO_8_VOLTAGE:
+        case AS3711_SD_CONTROL:
+        case AS3711_GPIO_SIGNAL_OUT:
+        case AS3711_GPIO_SIGNAL_IN:
+        case AS3711_SD_CONTROL_1:
+        case AS3711_SD_CONTROL_2:
+        case AS3711_CURR_CONTROL:
+        case AS3711_CURR1_VALUE:
+        case AS3711_CURR2_VALUE:
+        case AS3711_CURR3_VALUE:
+        case AS3711_STEPUP_CONTROL_1:
+        case AS3711_STEPUP_CONTROL_2:
+        case AS3711_STEPUP_CONTROL_4:
+        case AS3711_STEPUP_CONTROL_5:
+        case AS3711_REG_STATUS:
+        case AS3711_INTERRUPT_STATUS_1:
+        case AS3711_INTERRUPT_STATUS_2:
+        case AS3711_INTERRUPT_STATUS_3:
+        case AS3711_CHARGER_STATUS_1:
+        case AS3711_CHARGER_STATUS_2:
+        case AS3711_ASIC_ID_1:
+        case AS3711_ASIC_ID_2:
+                return true;
+        }
+        return false;
+}
+
+static const struct regmap_config as3711_regmap_config = {
+        .reg_bits = 8,
+        .val_bits = 8,
+        .volatile_reg = as3711_volatile_reg,
+        .readable_reg = as3711_readable_reg,
+        .precious_reg = as3711_precious_reg,
+        .max_register = AS3711_MAX_REGS,
+        .num_reg_defaults_raw = AS3711_MAX_REGS,
+        .cache_type = REGCACHE_RBTREE,
+};
+
+static int as3711_i2c_probe(struct i2c_client *client,
+                            const struct i2c_device_id *id)
+{
+        struct as3711 *as3711;
+        struct as3711_platform_data *pdata = client->dev.platform_data;
+        unsigned int id1, id2;
+        int ret;
+
+        if (!pdata)
+                dev_dbg(&client->dev, "Platform data not found\n");
+
+        as3711 = devm_kzalloc(&client->dev, sizeof(struct as3711), GFP_KERNEL);
+        if (!as3711) {
+                dev_err(&client->dev, "Memory allocation failed\n");
+                return -ENOMEM;
+        }
+
+        as3711->dev = &client->dev;
+        i2c_set_clientdata(client, as3711);
+
+        if (client->irq)
+                dev_notice(&client->dev, "IRQ not supported yet\n");
+
+        as3711->regmap = devm_regmap_init_i2c(client, &as3711_regmap_config);
+        if (IS_ERR(as3711->regmap)) {
+                ret = PTR_ERR(as3711->regmap);
+                dev_err(&client->dev, "regmap initialization failed: %d\n", ret);
+                return ret;
+        }
+
+        ret = regmap_read(as3711->regmap, AS3711_ASIC_ID_1, &id1);
+        if (!ret)
+                ret = regmap_read(as3711->regmap, AS3711_ASIC_ID_2, &id2);
+        if (ret < 0) {
+                dev_err(&client->dev, "regmap_read() failed: %d\n", ret);
+                return ret;
+        }
+        if (id1 != 0x8b)
+                return -ENODEV;
+        dev_info(as3711->dev, "AS3711 detected: %x:%x\n", id1, id2);
+
+        /* We can reuse as3711_subdevs[], it will be copied in mfd_add_devices() */
+        if (pdata) {
+                as3711_subdevs[AS3711_REGULATOR].platform_data = &pdata->regulator;
+                as3711_subdevs[AS3711_REGULATOR].pdata_size = sizeof(pdata->regulator);
+                as3711_subdevs[AS3711_BACKLIGHT].platform_data = &pdata->backlight;
+                as3711_subdevs[AS3711_BACKLIGHT].pdata_size = sizeof(pdata->backlight);
+        } else {
+                as3711_subdevs[AS3711_REGULATOR].platform_data = NULL;
+                as3711_subdevs[AS3711_REGULATOR].pdata_size = 0;
+                as3711_subdevs[AS3711_BACKLIGHT].platform_data = NULL;
+                as3711_subdevs[AS3711_BACKLIGHT].pdata_size = 0;
+        }
+
+        ret = mfd_add_devices(as3711->dev, -1, as3711_subdevs,
+                              ARRAY_SIZE(as3711_subdevs), NULL, 0, NULL);
+        if (ret < 0)
+                dev_err(&client->dev, "add mfd devices failed: %d\n", ret);
+
+        return ret;
+}
+
+static int as3711_i2c_remove(struct i2c_client *client)
+{
+        struct as3711 *as3711 = i2c_get_clientdata(client);
+
+        mfd_remove_devices(as3711->dev);
+        return 0;
+}
+
+static const struct i2c_device_id as3711_i2c_id[] = {
+        {.name = "as3711", .driver_data = 0},
+        {}
+};
+
+MODULE_DEVICE_TABLE(i2c, as3711_i2c_id);
+
+static struct i2c_driver as3711_i2c_driver = {
+        .driver = {
+                   .name = "as3711",
+                   .owner = THIS_MODULE,
+                   },
+        .probe = as3711_i2c_probe,
+        .remove = as3711_i2c_remove,
+        .id_table = as3711_i2c_id,
+};
+
+static int __init as3711_i2c_init(void)
+{
+        return i2c_add_driver(&as3711_i2c_driver);
+}
+/* Initialise early */
+subsys_initcall(as3711_i2c_init);
+
+static void __exit as3711_i2c_exit(void)
+{
+        i2c_del_driver(&as3711_i2c_driver);
+}
+module_exit(as3711_i2c_exit);
+
+MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
+MODULE_DESCRIPTION("AS3711 PMIC driver");
+MODULE_LICENSE("GPL v2");