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>

1 files changed, 262 insertions, 0 deletions

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");