aat2870-core.c

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/*
 * linux/drivers/mfd/aat2870-core.c
 *
 * Copyright (c) 2011, NVIDIA Corporation.
 * Author: Jin Park <[email protected]>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/mfd/core.h>
#include <linux/mfd/aat2870.h>
#include <linux/regulator/machine.h>

static struct aat2870_register aat2870_regs[AAT2870_REG_NUM] = {
    /* readable, writeable, value */
    { 0, 1, 0x00 }, /* 0x00 AAT2870_BL_CH_EN */
    { 0, 1, 0x16 }, /* 0x01 AAT2870_BLM */
    { 0, 1, 0x16 }, /* 0x02 AAT2870_BLS */
    { 0, 1, 0x56 }, /* 0x03 AAT2870_BL1 */
    { 0, 1, 0x56 }, /* 0x04 AAT2870_BL2 */
    { 0, 1, 0x56 }, /* 0x05 AAT2870_BL3 */
    { 0, 1, 0x56 }, /* 0x06 AAT2870_BL4 */
    { 0, 1, 0x56 }, /* 0x07 AAT2870_BL5 */
    { 0, 1, 0x56 }, /* 0x08 AAT2870_BL6 */
    { 0, 1, 0x56 }, /* 0x09 AAT2870_BL7 */
    { 0, 1, 0x56 }, /* 0x0A AAT2870_BL8 */
    { 0, 1, 0x00 }, /* 0x0B AAT2870_FLR */
    { 0, 1, 0x03 }, /* 0x0C AAT2870_FM */
    { 0, 1, 0x03 }, /* 0x0D AAT2870_FS */
    { 0, 1, 0x10 }, /* 0x0E AAT2870_ALS_CFG0 */
    { 0, 1, 0x06 }, /* 0x0F AAT2870_ALS_CFG1 */
    { 0, 1, 0x00 }, /* 0x10 AAT2870_ALS_CFG2 */
    { 1, 0, 0x00 }, /* 0x11 AAT2870_AMB */
    { 0, 1, 0x00 }, /* 0x12 AAT2870_ALS0 */
    { 0, 1, 0x00 }, /* 0x13 AAT2870_ALS1 */
    { 0, 1, 0x00 }, /* 0x14 AAT2870_ALS2 */
    { 0, 1, 0x00 }, /* 0x15 AAT2870_ALS3 */
    { 0, 1, 0x00 }, /* 0x16 AAT2870_ALS4 */
    { 0, 1, 0x00 }, /* 0x17 AAT2870_ALS5 */
    { 0, 1, 0x00 }, /* 0x18 AAT2870_ALS6 */
    { 0, 1, 0x00 }, /* 0x19 AAT2870_ALS7 */
    { 0, 1, 0x00 }, /* 0x1A AAT2870_ALS8 */
    { 0, 1, 0x00 }, /* 0x1B AAT2870_ALS9 */
    { 0, 1, 0x00 }, /* 0x1C AAT2870_ALSA */
    { 0, 1, 0x00 }, /* 0x1D AAT2870_ALSB */
    { 0, 1, 0x00 }, /* 0x1E AAT2870_ALSC */
    { 0, 1, 0x00 }, /* 0x1F AAT2870_ALSD */
    { 0, 1, 0x00 }, /* 0x20 AAT2870_ALSE */
    { 0, 1, 0x00 }, /* 0x21 AAT2870_ALSF */
    { 0, 1, 0x00 }, /* 0x22 AAT2870_SUB_SET */
    { 0, 1, 0x00 }, /* 0x23 AAT2870_SUB_CTRL */
    { 0, 1, 0x00 }, /* 0x24 AAT2870_LDO_AB */
    { 0, 1, 0x00 }, /* 0x25 AAT2870_LDO_CD */
    { 0, 1, 0x00 }, /* 0x26 AAT2870_LDO_EN */
};

static struct mfd_cell aat2870_devs[] = {
    {
        .name = "aat2870-backlight",
        .id = AAT2870_ID_BL,
        .pdata_size = sizeof(struct aat2870_bl_platform_data),
    },
    {
        .name = "aat2870-regulator",
        .id = AAT2870_ID_LDOA,
        .pdata_size = sizeof(struct regulator_init_data),
    },
    {
        .name = "aat2870-regulator",
        .id = AAT2870_ID_LDOB,
        .pdata_size = sizeof(struct regulator_init_data),
    },
    {
        .name = "aat2870-regulator",
        .id = AAT2870_ID_LDOC,
        .pdata_size = sizeof(struct regulator_init_data),
    },
    {
        .name = "aat2870-regulator",
        .id = AAT2870_ID_LDOD,
        .pdata_size = sizeof(struct regulator_init_data),
    },
};

static int __aat2870_read(struct aat2870_data *aat2870, u8 addr, u8 *val)
{
    int ret;

    if (addr >= AAT2870_REG_NUM) {
        dev_err(aat2870->dev, "Invalid address, 0x%02x\n", addr);
        return -EINVAL;
    }

    if (!aat2870->reg_cache[addr].readable) {
        *val = aat2870->reg_cache[addr].value;
        goto out;
    }

    ret = i2c_master_send(aat2870->client, &addr, 1);
    if (ret < 0)
        return ret;
    if (ret != 1)
        return -EIO;

    ret = i2c_master_recv(aat2870->client, val, 1);
    if (ret < 0)
        return ret;
    if (ret != 1)
        return -EIO;

out:
    dev_dbg(aat2870->dev, "read: addr=0x%02x, val=0x%02x\n", addr, *val);
    return 0;
}

static int __aat2870_write(struct aat2870_data *aat2870, u8 addr, u8 val)
{
    u8 msg[2];
    int ret;

    if (addr >= AAT2870_REG_NUM) {
        dev_err(aat2870->dev, "Invalid address, 0x%02x\n", addr);
        return -EINVAL;
    }

    if (!aat2870->reg_cache[addr].writeable) {
        dev_err(aat2870->dev, "Address 0x%02x is not writeable\n",
            addr);
        return -EINVAL;
    }

    msg[0] = addr;
    msg[1] = val;
    ret = i2c_master_send(aat2870->client, msg, 2);
    if (ret < 0)
        return ret;
    if (ret != 2)
        return -EIO;

    aat2870->reg_cache[addr].value = val;

    dev_dbg(aat2870->dev, "write: addr=0x%02x, val=0x%02x\n", addr, val);
    return 0;
}

static int aat2870_read(struct aat2870_data *aat2870, u8 addr, u8 *val)
{
    int ret;

    mutex_lock(&aat2870->io_lock);
    ret = __aat2870_read(aat2870, addr, val);
    mutex_unlock(&aat2870->io_lock);

    return ret;
}

static int aat2870_write(struct aat2870_data *aat2870, u8 addr, u8 val)
{
    int ret;

    mutex_lock(&aat2870->io_lock);
    ret = __aat2870_write(aat2870, addr, val);
    mutex_unlock(&aat2870->io_lock);

    return ret;
}

static int aat2870_update(struct aat2870_data *aat2870, u8 addr, u8 mask,
              u8 val)
{
    int change;
    u8 old_val, new_val;
    int ret;

    mutex_lock(&aat2870->io_lock);

    ret = __aat2870_read(aat2870, addr, &old_val);
    if (ret)
        goto out_unlock;

    new_val = (old_val & ~mask) | (val & mask);
    change = old_val != new_val;
    if (change)
        ret = __aat2870_write(aat2870, addr, new_val);

out_unlock:
    mutex_unlock(&aat2870->io_lock);

    return ret;
}

static inline void aat2870_enable(struct aat2870_data *aat2870)
{
    if (aat2870->en_pin >= 0)
        gpio_set_value(aat2870->en_pin, 1);

    aat2870->is_enable = 1;
}

static inline void aat2870_disable(struct aat2870_data *aat2870)
{
    if (aat2870->en_pin >= 0)
        gpio_set_value(aat2870->en_pin, 0);

    aat2870->is_enable = 0;
}

#ifdef CONFIG_DEBUG_FS
static ssize_t aat2870_dump_reg(struct aat2870_data *aat2870, char *buf)
{
    u8 addr, val;
    ssize_t count = 0;
    int ret;

    count += sprintf(buf, "aat2870 registers\n");
    for (addr = 0; addr < AAT2870_REG_NUM; addr++) {
        count += sprintf(buf + count, "0x%02x: ", addr);
        if (count >= PAGE_SIZE - 1)
            break;

        ret = aat2870->read(aat2870, addr, &val);
        if (ret == 0)
            count += snprintf(buf + count, PAGE_SIZE - count,
                      "0x%02x", val);
        else
            count += snprintf(buf + count, PAGE_SIZE - count,
                      "<read fail: %d>", ret);

        if (count >= PAGE_SIZE - 1)
            break;

        count += snprintf(buf + count, PAGE_SIZE - count, "\n");
        if (count >= PAGE_SIZE - 1)
            break;
    }

    /* Truncate count; min() would cause a warning */
    if (count >= PAGE_SIZE)
        count = PAGE_SIZE - 1;

    return count;
}

static ssize_t aat2870_reg_read_file(struct file *file, char __user *user_buf,
                     size_t count, loff_t *ppos)
{
    struct aat2870_data *aat2870 = file->private_data;
    char *buf;
    ssize_t ret;

    buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
    if (!buf)
        return -ENOMEM;

    ret = aat2870_dump_reg(aat2870, buf);
    if (ret >= 0)
        ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);

    kfree(buf);

    return ret;
}

static ssize_t aat2870_reg_write_file(struct file *file,
                      const char __user *user_buf, size_t count,
                      loff_t *ppos)
{
    struct aat2870_data *aat2870 = file->private_data;
    char buf[32];
    ssize_t buf_size;
    char *start = buf;
    unsigned long addr, val;
    int ret;

    buf_size = min(count, (sizeof(buf)-1));
    if (copy_from_user(buf, user_buf, buf_size)) {
        dev_err(aat2870->dev, "Failed to copy from user\n");
        return -EFAULT;
    }
    buf[buf_size] = 0;

    while (*start == ' ')
        start++;

    addr = simple_strtoul(start, &start, 16);
    if (addr >= AAT2870_REG_NUM) {
        dev_err(aat2870->dev, "Invalid address, 0x%lx\n", addr);
        return -EINVAL;
    }

    while (*start == ' ')
        start++;

    if (strict_strtoul(start, 16, &val))
        return -EINVAL;

    ret = aat2870->write(aat2870, (u8)addr, (u8)val);
    if (ret)
        return ret;

    return buf_size;
}

static const struct file_operations aat2870_reg_fops = {
    .open = simple_open,
    .read = aat2870_reg_read_file,
    .write = aat2870_reg_write_file,
};

static void aat2870_init_debugfs(struct aat2870_data *aat2870)
{
    aat2870->dentry_root = debugfs_create_dir("aat2870", NULL);
    if (!aat2870->dentry_root) {
        dev_warn(aat2870->dev,
             "Failed to create debugfs root directory\n");
        return;
    }

    aat2870->dentry_reg = debugfs_create_file("regs", 0644,
                          aat2870->dentry_root,
                          aat2870, &aat2870_reg_fops);
    if (!aat2870->dentry_reg)
        dev_warn(aat2870->dev,
             "Failed to create debugfs register file\n");
}

static void aat2870_uninit_debugfs(struct aat2870_data *aat2870)
{
    debugfs_remove_recursive(aat2870->dentry_root);
}
#else
static inline void aat2870_init_debugfs(struct aat2870_data *aat2870)
{
}

static inline void aat2870_uninit_debugfs(struct aat2870_data *aat2870)
{
}
#endif /* CONFIG_DEBUG_FS */

static int aat2870_i2c_probe(struct i2c_client *client,
                 const struct i2c_device_id *id)
{
    struct aat2870_platform_data *pdata = client->dev.platform_data;
    struct aat2870_data *aat2870;
    int i, j;
    int ret = 0;

    aat2870 = kzalloc(sizeof(struct aat2870_data), GFP_KERNEL);
    if (!aat2870) {
        dev_err(&client->dev,
            "Failed to allocate memory for aat2870\n");
        ret = -ENOMEM;
        goto out;
    }

    aat2870->dev = &client->dev;
    dev_set_drvdata(aat2870->dev, aat2870);

    aat2870->client = client;
    i2c_set_clientdata(client, aat2870);

    aat2870->reg_cache = aat2870_regs;

    if (pdata->en_pin < 0)
        aat2870->en_pin = -1;
    else
        aat2870->en_pin = pdata->en_pin;

    aat2870->init = pdata->init;
    aat2870->uninit = pdata->uninit;
    aat2870->read = aat2870_read;
    aat2870->write = aat2870_write;
    aat2870->update = aat2870_update;

    mutex_init(&aat2870->io_lock);

    if (aat2870->init)
        aat2870->init(aat2870);

    if (aat2870->en_pin >= 0) {
        ret = gpio_request_one(aat2870->en_pin, GPIOF_OUT_INIT_HIGH,
                       "aat2870-en");
        if (ret < 0) {
            dev_err(&client->dev,
                "Failed to request GPIO %d\n", aat2870->en_pin);
            goto out_kfree;
        }
    }

    aat2870_enable(aat2870);

    for (i = 0; i < pdata->num_subdevs; i++) {
        for (j = 0; j < ARRAY_SIZE(aat2870_devs); j++) {
            if ((pdata->subdevs[i].id == aat2870_devs[j].id) &&
                    !strcmp(pdata->subdevs[i].name,
                        aat2870_devs[j].name)) {
                aat2870_devs[j].platform_data =
                    pdata->subdevs[i].platform_data;
                break;
            }
        }
    }

    ret = mfd_add_devices(aat2870->dev, 0, aat2870_devs,
                  ARRAY_SIZE(aat2870_devs), NULL, 0, NULL);
    if (ret != 0) {
        dev_err(aat2870->dev, "Failed to add subdev: %d\n", ret);
        goto out_disable;
    }

    aat2870_init_debugfs(aat2870);

    return 0;

out_disable:
    aat2870_disable(aat2870);
    if (aat2870->en_pin >= 0)
        gpio_free(aat2870->en_pin);
out_kfree:
    kfree(aat2870);
out:
    return ret;
}

static int aat2870_i2c_remove(struct i2c_client *client)
{
    struct aat2870_data *aat2870 = i2c_get_clientdata(client);

    aat2870_uninit_debugfs(aat2870);

    mfd_remove_devices(aat2870->dev);
    aat2870_disable(aat2870);
    if (aat2870->en_pin >= 0)
        gpio_free(aat2870->en_pin);
    if (aat2870->uninit)
        aat2870->uninit(aat2870);
    kfree(aat2870);

    return 0;
}

#ifdef CONFIG_PM_SLEEP
static int aat2870_i2c_suspend(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct aat2870_data *aat2870 = i2c_get_clientdata(client);

    aat2870_disable(aat2870);

    return 0;
}

static int aat2870_i2c_resume(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct aat2870_data *aat2870 = i2c_get_clientdata(client);
    struct aat2870_register *reg = NULL;
    int i;

    aat2870_enable(aat2870);

    /* restore registers */
    for (i = 0; i < AAT2870_REG_NUM; i++) {
        reg = &aat2870->reg_cache[i];
        if (reg->writeable)
            aat2870->write(aat2870, i, reg->value);
    }

    return 0;
}
#endif /* CONFIG_PM_SLEEP */

static SIMPLE_DEV_PM_OPS(aat2870_pm_ops, aat2870_i2c_suspend,
             aat2870_i2c_resume);

static const struct i2c_device_id aat2870_i2c_id_table[] = {
    { "aat2870", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, aat2870_i2c_id_table);

static struct i2c_driver aat2870_i2c_driver = {
    .driver = {
        .name   = "aat2870",
        .owner  = THIS_MODULE,
        .pm = &aat2870_pm_ops,
    },
    .probe      = aat2870_i2c_probe,
    .remove     = aat2870_i2c_remove,
    .id_table   = aat2870_i2c_id_table,
};

static int __init aat2870_init(void)
{
    return i2c_add_driver(&aat2870_i2c_driver);
}
subsys_initcall(aat2870_init);

static void __exit aat2870_exit(void)
{
    i2c_del_driver(&aat2870_i2c_driver);
}
module_exit(aat2870_exit);

MODULE_DESCRIPTION("Core support for the AnalogicTech AAT2870");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jin Park <[email protected]>");