mfd: Initial max8925 support

Basic Max8925 support, which is a power management IC from Maxim
Semiconductor.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

4 files changed, 483 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 815907eb70a4..ee416eefb8e9 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -194,6 +194,15 @@ config PMIC_ADP5520
           individual components like LCD backlight, LEDs, GPIOs and Kepad
           under the corresponding menus.
 
+config MFD_MAX8925
+        tristate "Maxim Semiconductor MAX8925 PMIC Support"
+        depends on I2C
+        help
+          Say yes here to support for Maxim Semiconductor MAX8925. This is
+          a Power Management IC. This driver provies common support for
+          accessing the device, additional drivers must be enabled in order
+          to use the functionality of the device.
+
 config MFD_WM8400
         tristate "Support Wolfson Microelectronics WM8400"
         select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 1e3ae062c1f6..261635700243 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -49,6 +49,8 @@ endif
 obj-$(CONFIG_UCB1400_CORE)      += ucb1400_core.o
 
 obj-$(CONFIG_PMIC_DA903X)       += da903x.o
+max8925-objs                    := max8925-core.o max8925-i2c.o
+obj-$(CONFIG_MFD_MAX8925)       += max8925.o
 
 obj-$(CONFIG_MFD_PCF50633)      += pcf50633-core.o
 obj-$(CONFIG_PCF50633_ADC)      += pcf50633-adc.o
diff --git a/drivers/mfd/max8925-core.c b/drivers/mfd/max8925-core.c
new file mode 100644
index 000000000000..3e26267960b1
--- /dev/null
+++ b/drivers/mfd/max8925-core.c
@@ -0,0 +1,262 @@
+/*
+ * Base driver for Maxim MAX8925
+ *
+ * Copyright (C) 2009 Marvell International Ltd.
+ *      Haojian Zhuang <haojian.zhuang@marvell.com>
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max8925.h>
+
+#define IRQ_MODE_STATUS         0
+#define IRQ_MODE_MASK           1
+
+static int __get_irq_offset(struct max8925_chip *chip, int irq, int mode,
+                            int *offset, int *bit)
+{
+        if (!offset || !bit)
+                return -EINVAL;
+
+        switch (chip->chip_id) {
+        case MAX8925_GPM:
+                *bit = irq % BITS_PER_BYTE;
+                if (irq < (BITS_PER_BYTE << 1)) {       /* irq = [0,15] */
+                        *offset = (mode) ? MAX8925_CHG_IRQ1_MASK
+                                : MAX8925_CHG_IRQ1;
+                        if (irq >= BITS_PER_BYTE)
+                                (*offset)++;
+                } else {                                /* irq = [16,31] */
+                        *offset = (mode) ? MAX8925_ON_OFF_IRQ1_MASK
+                                : MAX8925_ON_OFF_IRQ1;
+                        if (irq >= (BITS_PER_BYTE * 3))
+                                (*offset)++;
+                }
+                break;
+        case MAX8925_ADC:
+                *bit = irq % BITS_PER_BYTE;
+                *offset = (mode) ? MAX8925_TSC_IRQ_MASK : MAX8925_TSC_IRQ;
+                break;
+        default:
+                goto out;
+        }
+        return 0;
+out:
+        dev_err(chip->dev, "Wrong irq #%d is assigned\n", irq);
+        return -EINVAL;
+}
+
+static int __check_irq(int irq)
+{
+        if ((irq < 0) || (irq >= MAX8925_NUM_IRQ))
+                return -EINVAL;
+        return 0;
+}
+
+int max8925_mask_irq(struct max8925_chip *chip, int irq)
+{
+        int offset, bit, ret;
+
+        ret = __get_irq_offset(chip, irq, IRQ_MODE_MASK, &offset, &bit);
+        if (ret < 0)
+                return ret;
+        ret = max8925_set_bits(chip->i2c, offset, 1 << bit, 1 << bit);
+        return ret;
+}
+
+int max8925_unmask_irq(struct max8925_chip *chip, int irq)
+{
+        int offset, bit, ret;
+
+        ret = __get_irq_offset(chip, irq, IRQ_MODE_MASK, &offset, &bit);
+        if (ret < 0)
+                return ret;
+        ret = max8925_set_bits(chip->i2c, offset, 1 << bit, 0);
+        return ret;
+}
+
+#define INT_STATUS_NUM          (MAX8925_NUM_IRQ / BITS_PER_BYTE)
+
+static irqreturn_t max8925_irq_thread(int irq, void *data)
+{
+        struct max8925_chip *chip = data;
+        unsigned long irq_status[INT_STATUS_NUM];
+        unsigned char status_buf[INT_STATUS_NUM << 1];
+        int i, ret;
+
+        memset(irq_status, 0, sizeof(unsigned long) * INT_STATUS_NUM);
+
+        /* all these interrupt status registers are read-only */
+        switch (chip->chip_id) {
+        case MAX8925_GPM:
+                ret = max8925_bulk_read(chip->i2c, MAX8925_CHG_IRQ1,
+                                        4, status_buf);
+                if (ret < 0)
+                        goto out;
+                ret = max8925_bulk_read(chip->i2c, MAX8925_ON_OFF_IRQ1,
+                                        2, &status_buf[4]);
+                if (ret < 0)
+                        goto out;
+                ret = max8925_bulk_read(chip->i2c, MAX8925_ON_OFF_IRQ2,
+                                        2, &status_buf[6]);
+                if (ret < 0)
+                        goto out;
+                /* clear masked interrupt status */
+                status_buf[0] &= (~status_buf[2] & CHG_IRQ1_MASK);
+                irq_status[0] |= status_buf[0];
+                status_buf[1] &= (~status_buf[3] & CHG_IRQ2_MASK);
+                irq_status[0] |= (status_buf[1] << BITS_PER_BYTE);
+                status_buf[4] &= (~status_buf[5] & ON_OFF_IRQ1_MASK);
+                irq_status[0] |= (status_buf[4] << (BITS_PER_BYTE * 2));
+                status_buf[6] &= (~status_buf[7] & ON_OFF_IRQ2_MASK);
+                irq_status[0] |= (status_buf[6] << (BITS_PER_BYTE * 3));
+                break;
+        case MAX8925_ADC:
+                ret = max8925_bulk_read(chip->i2c, MAX8925_TSC_IRQ,
+                                        2, status_buf);
+                if (ret < 0)
+                        goto out;
+                /* clear masked interrupt status */
+                status_buf[0] &= (~status_buf[1] & TSC_IRQ_MASK);
+                irq_status[0] |= status_buf[0];
+                break;
+        default:
+                goto out;
+        }
+
+        for_each_bit(i, &irq_status[0], MAX8925_NUM_IRQ) {
+                clear_bit(i, irq_status);
+                dev_dbg(chip->dev, "Servicing IRQ #%d in %s\n", i, chip->name);
+
+                mutex_lock(&chip->irq_lock);
+                if (chip->irq[i].handler)
+                        chip->irq[i].handler(i, chip->irq[i].data);
+                else {
+                        max8925_mask_irq(chip, i);
+                        dev_err(chip->dev, "Noboday cares IRQ #%d in %s. "
+                                "Now mask it.\n", i, chip->name);
+                }
+                mutex_unlock(&chip->irq_lock);
+        }
+out:
+        return IRQ_HANDLED;
+}
+
+int max8925_request_irq(struct max8925_chip *chip, int irq,
+                        irq_handler_t handler, void *data)
+{
+        if ((__check_irq(irq) < 0) || !handler)
+                return -EINVAL;
+
+        mutex_lock(&chip->irq_lock);
+        chip->irq[irq].handler = handler;
+        chip->irq[irq].data = data;
+        mutex_unlock(&chip->irq_lock);
+        return 0;
+}
+EXPORT_SYMBOL(max8925_request_irq);
+
+int max8925_free_irq(struct max8925_chip *chip, int irq)
+{
+        if (__check_irq(irq) < 0)
+                return -EINVAL;
+
+        mutex_lock(&chip->irq_lock);
+        chip->irq[irq].handler = NULL;
+        chip->irq[irq].data = NULL;
+        mutex_unlock(&chip->irq_lock);
+        return 0;
+}
+EXPORT_SYMBOL(max8925_free_irq);
+
+static int __devinit device_gpm_init(struct max8925_chip *chip,
+                                      struct i2c_client *i2c,
+                                      struct max8925_platform_data *pdata)
+{
+        int ret;
+
+        /* mask all IRQs */
+        ret = max8925_set_bits(i2c, MAX8925_CHG_IRQ1_MASK, 0x7, 0x7);
+        if (ret < 0)
+                goto out;
+        ret = max8925_set_bits(i2c, MAX8925_CHG_IRQ2_MASK, 0xff, 0xff);
+        if (ret < 0)
+                goto out;
+        ret = max8925_set_bits(i2c, MAX8925_ON_OFF_IRQ1_MASK, 0xff, 0xff);
+        if (ret < 0)
+                goto out;
+        ret = max8925_set_bits(i2c, MAX8925_ON_OFF_IRQ2_MASK, 0x3, 0x3);
+        if (ret < 0)
+                goto out;
+
+        chip->name = "GPM";
+        memset(chip->irq, 0, sizeof(struct max8925_irq) * MAX8925_NUM_IRQ);
+        ret = request_threaded_irq(i2c->irq, NULL, max8925_irq_thread,
+                                IRQF_ONESHOT | IRQF_TRIGGER_LOW,
+                                "max8925-gpm", chip);
+        if (ret < 0) {
+                dev_err(chip->dev, "Failed to request IRQ #%d.\n", i2c->irq);
+                goto out;
+        }
+        chip->chip_irq = i2c->irq;
+
+        /* enable hard-reset for ONKEY power-off */
+        max8925_set_bits(i2c, MAX8925_SYSENSEL, 0x80, 0x80);
+out:
+        return ret;
+}
+
+static int __devinit device_adc_init(struct max8925_chip *chip,
+                                     struct i2c_client *i2c,
+                                     struct max8925_platform_data *pdata)
+{
+        int ret;
+
+        /* mask all IRQs */
+        ret = max8925_set_bits(i2c, MAX8925_TSC_IRQ_MASK, 3, 3);
+
+        chip->name = "ADC";
+        memset(chip->irq, 0, sizeof(struct max8925_irq) * MAX8925_NUM_IRQ);
+        ret = request_threaded_irq(i2c->irq, NULL, max8925_irq_thread,
+                                IRQF_ONESHOT | IRQF_TRIGGER_LOW,
+                                "max8925-adc", chip);
+        if (ret < 0) {
+                dev_err(chip->dev, "Failed to request IRQ #%d.\n", i2c->irq);
+                goto out;
+        }
+        chip->chip_irq = i2c->irq;
+out:
+        return ret;
+}
+
+int __devinit max8925_device_init(struct max8925_chip *chip,
+                                  struct max8925_platform_data *pdata)
+{
+        switch (chip->chip_id) {
+        case MAX8925_GPM:
+                device_gpm_init(chip, chip->i2c, pdata);
+                break;
+        case MAX8925_ADC:
+                device_adc_init(chip, chip->i2c, pdata);
+                break;
+        }
+        return 0;
+}
+
+void max8925_device_exit(struct max8925_chip *chip)
+{
+        if (chip->chip_irq >= 0)
+                free_irq(chip->chip_irq, chip);
+}
+
+MODULE_DESCRIPTION("PMIC Driver for Maxim MAX8925");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mfd/max8925-i2c.c b/drivers/mfd/max8925-i2c.c
new file mode 100644
index 000000000000..942068e730f9
--- /dev/null
+++ b/drivers/mfd/max8925-i2c.c
@@ -0,0 +1,210 @@
+/*
+ * I2C driver for Maxim MAX8925
+ *
+ * Copyright (C) 2009 Marvell International Ltd.
+ *      Haojian Zhuang <haojian.zhuang@marvell.com>
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+#include <linux/mfd/max8925.h>
+
+static inline int max8925_read_device(struct i2c_client *i2c,
+                                      int reg, int bytes, void *dest)
+{
+        unsigned char data;
+        unsigned char *buf;
+        int ret;
+
+        buf = kzalloc(bytes + 1, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+
+        data = (unsigned char)reg;
+        ret = i2c_master_send(i2c, &data, 1);
+        if (ret < 0)
+                return ret;
+
+        ret = i2c_master_recv(i2c, buf, bytes + 1);
+        if (ret < 0)
+                return ret;
+        memcpy(dest, buf, bytes);
+        return 0;
+}
+
+static inline int max8925_write_device(struct i2c_client *i2c,
+                                       int reg, int bytes, void *src)
+{
+        unsigned char buf[bytes + 1];
+        int ret;
+
+        buf[0] = (unsigned char)reg;
+        memcpy(&buf[1], src, bytes);
+
+        ret = i2c_master_send(i2c, buf, bytes + 1);
+        if (ret < 0)
+                return ret;
+        return 0;
+}
+
+int max8925_reg_read(struct i2c_client *i2c, int reg)
+{
+        struct max8925_chip *chip = i2c_get_clientdata(i2c);
+        unsigned char data;
+        int ret;
+
+        mutex_lock(&chip->io_lock);
+        ret = max8925_read_device(i2c, reg, 1, &data);
+        mutex_unlock(&chip->io_lock);
+
+        if (ret < 0)
+                return ret;
+        else
+                return (int)data;
+}
+EXPORT_SYMBOL(max8925_reg_read);
+
+int max8925_reg_write(struct i2c_client *i2c, int reg,
+                unsigned char data)
+{
+        struct max8925_chip *chip = i2c_get_clientdata(i2c);
+        int ret;
+
+        mutex_lock(&chip->io_lock);
+        ret = max8925_write_device(i2c, reg, 1, &data);
+        mutex_unlock(&chip->io_lock);
+
+        return ret;
+}
+EXPORT_SYMBOL(max8925_reg_write);
+
+int max8925_bulk_read(struct i2c_client *i2c, int reg,
+                int count, unsigned char *buf)
+{
+        struct max8925_chip *chip = i2c_get_clientdata(i2c);
+        int ret;
+
+        mutex_lock(&chip->io_lock);
+        ret = max8925_read_device(i2c, reg, count, buf);
+        mutex_unlock(&chip->io_lock);
+
+        return ret;
+}
+EXPORT_SYMBOL(max8925_bulk_read);
+
+int max8925_bulk_write(struct i2c_client *i2c, int reg,
+                int count, unsigned char *buf)
+{
+        struct max8925_chip *chip = i2c_get_clientdata(i2c);
+        int ret;
+
+        mutex_lock(&chip->io_lock);
+        ret = max8925_write_device(i2c, reg, count, buf);
+        mutex_unlock(&chip->io_lock);
+
+        return ret;
+}
+EXPORT_SYMBOL(max8925_bulk_write);
+
+int max8925_set_bits(struct i2c_client *i2c, int reg,
+                unsigned char mask, unsigned char data)
+{
+        struct max8925_chip *chip = i2c_get_clientdata(i2c);
+        unsigned char value;
+        int ret;
+
+        mutex_lock(&chip->io_lock);
+        ret = max8925_read_device(i2c, reg, 1, &value);
+        if (ret < 0)
+                goto out;
+        value &= ~mask;
+        value |= data;
+        ret = max8925_write_device(i2c, reg, 1, &value);
+out:
+        mutex_unlock(&chip->io_lock);
+        return ret;
+}
+EXPORT_SYMBOL(max8925_set_bits);
+
+
+static const struct i2c_device_id max8925_id_table[] = {
+        { "max8925", 0 },
+        {}
+};
+MODULE_DEVICE_TABLE(i2c, max8925_id_table);
+
+static int __devinit max8925_probe(struct i2c_client *client,
+                                   const struct i2c_device_id *id)
+{
+        struct max8925_platform_data *pdata = client->dev.platform_data;
+        struct max8925_chip *chip;
+
+        if (!pdata) {
+                pr_info("%s: platform data is missing\n", __func__);
+                return -EINVAL;
+        }
+        if ((pdata->chip_id <= MAX8925_INVALID)
+                || (pdata->chip_id >= MAX8925_MAX)) {
+                pr_info("#%s: wrong chip identification\n", __func__);
+                return -EINVAL;
+        }
+
+        chip = kzalloc(sizeof(struct max8925_chip), GFP_KERNEL);
+        if (chip == NULL)
+                return -ENOMEM;
+        chip->i2c = client;
+        chip->chip_id = pdata->chip_id;
+        i2c_set_clientdata(client, chip);
+        chip->dev = &client->dev;
+        mutex_init(&chip->io_lock);
+        dev_set_drvdata(chip->dev, chip);
+        max8925_device_init(chip, pdata);
+
+        return 0;
+}
+
+static int __devexit max8925_remove(struct i2c_client *client)
+{
+        struct max8925_chip *chip = i2c_get_clientdata(client);
+
+        max8925_device_exit(chip);
+        i2c_set_clientdata(client, NULL);
+        kfree(chip);
+        return 0;
+}
+
+static struct i2c_driver max8925_driver = {
+        .driver = {
+                .name   = "max8925",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = max8925_probe,
+        .remove         = __devexit_p(max8925_remove),
+        .id_table       = max8925_id_table,
+};
+
+static int __init max8925_i2c_init(void)
+{
+        int ret;
+
+        ret = i2c_add_driver(&max8925_driver);
+        if (ret != 0)
+                pr_err("Failed to register MAX8925 I2C driver: %d\n", ret);
+        return ret;
+}
+subsys_initcall(max8925_i2c_init);
+
+static void __exit max8925_i2c_exit(void)
+{
+        i2c_del_driver(&max8925_driver);
+}
+module_exit(max8925_i2c_exit);
+
+MODULE_DESCRIPTION("I2C Driver for Maxim 8925");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
+MODULE_LICENSE("GPL");