anatop-regulator.c

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/*
 * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.

 * 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 Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <linux/slab.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/mfd/syscon.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>

struct anatop_regulator {
    const char *name;
    u32 control_reg;
    struct regmap *anatop;
    int vol_bit_shift;
    int vol_bit_width;
    int min_bit_val;
    int min_voltage;
    int max_voltage;
    struct regulator_desc rdesc;
    struct regulator_init_data *initdata;
};

static int anatop_regmap_set_voltage_sel(struct regulator_dev *reg,
                    unsigned selector)
{
    struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
    u32 val, mask;

    if (!anatop_reg->control_reg)
        return -ENOTSUPP;

    val = anatop_reg->min_bit_val + selector;
    dev_dbg(&reg->dev, "%s: calculated val %d\n", __func__, val);
    mask = ((1 << anatop_reg->vol_bit_width) - 1) <<
        anatop_reg->vol_bit_shift;
    val <<= anatop_reg->vol_bit_shift;
    regmap_update_bits(anatop_reg->anatop, anatop_reg->control_reg,
                mask, val);

    return 0;
}

static int anatop_regmap_get_voltage_sel(struct regulator_dev *reg)
{
    struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
    u32 val, mask;

    if (!anatop_reg->control_reg)
        return -ENOTSUPP;

    regmap_read(anatop_reg->anatop, anatop_reg->control_reg, &val);
    mask = ((1 << anatop_reg->vol_bit_width) - 1) <<
        anatop_reg->vol_bit_shift;
    val = (val & mask) >> anatop_reg->vol_bit_shift;

    return val - anatop_reg->min_bit_val;
}

static struct regulator_ops anatop_rops = {
    .set_voltage_sel = anatop_regmap_set_voltage_sel,
    .get_voltage_sel = anatop_regmap_get_voltage_sel,
    .list_voltage = regulator_list_voltage_linear,
    .map_voltage = regulator_map_voltage_linear,
};

static int __devinit anatop_regulator_probe(struct platform_device *pdev)
{
    struct device *dev = &pdev->dev;
    struct device_node *np = dev->of_node;
    struct device_node *anatop_np;
    struct regulator_desc *rdesc;
    struct regulator_dev *rdev;
    struct anatop_regulator *sreg;
    struct regulator_init_data *initdata;
    struct regulator_config config = { };
    int ret = 0;

    initdata = of_get_regulator_init_data(dev, np);
    sreg = devm_kzalloc(dev, sizeof(*sreg), GFP_KERNEL);
    if (!sreg)
        return -ENOMEM;
    sreg->initdata = initdata;
    sreg->name = kstrdup(of_get_property(np, "regulator-name", NULL),
                 GFP_KERNEL);
    rdesc = &sreg->rdesc;
    memset(rdesc, 0, sizeof(*rdesc));
    rdesc->name = sreg->name;
    rdesc->ops = &anatop_rops;
    rdesc->type = REGULATOR_VOLTAGE;
    rdesc->owner = THIS_MODULE;

    anatop_np = of_get_parent(np);
    if (!anatop_np)
        return -ENODEV;
    sreg->anatop = syscon_node_to_regmap(anatop_np);
    of_node_put(anatop_np);
    if (IS_ERR(sreg->anatop))
        return PTR_ERR(sreg->anatop);

    ret = of_property_read_u32(np, "anatop-reg-offset",
                   &sreg->control_reg);
    if (ret) {
        dev_err(dev, "no anatop-reg-offset property set\n");
        goto anatop_probe_end;
    }
    ret = of_property_read_u32(np, "anatop-vol-bit-width",
                   &sreg->vol_bit_width);
    if (ret) {
        dev_err(dev, "no anatop-vol-bit-width property set\n");
        goto anatop_probe_end;
    }
    ret = of_property_read_u32(np, "anatop-vol-bit-shift",
                   &sreg->vol_bit_shift);
    if (ret) {
        dev_err(dev, "no anatop-vol-bit-shift property set\n");
        goto anatop_probe_end;
    }
    ret = of_property_read_u32(np, "anatop-min-bit-val",
                   &sreg->min_bit_val);
    if (ret) {
        dev_err(dev, "no anatop-min-bit-val property set\n");
        goto anatop_probe_end;
    }
    ret = of_property_read_u32(np, "anatop-min-voltage",
                   &sreg->min_voltage);
    if (ret) {
        dev_err(dev, "no anatop-min-voltage property set\n");
        goto anatop_probe_end;
    }
    ret = of_property_read_u32(np, "anatop-max-voltage",
                   &sreg->max_voltage);
    if (ret) {
        dev_err(dev, "no anatop-max-voltage property set\n");
        goto anatop_probe_end;
    }

    rdesc->n_voltages = (sreg->max_voltage - sreg->min_voltage)
        / 25000 + 1;
    rdesc->min_uV = sreg->min_voltage;
    rdesc->uV_step = 25000;

    config.dev = &pdev->dev;
    config.init_data = initdata;
    config.driver_data = sreg;
    config.of_node = pdev->dev.of_node;

    /* register regulator */
    rdev = regulator_register(rdesc, &config);
    if (IS_ERR(rdev)) {
        dev_err(dev, "failed to register %s\n",
            rdesc->name);
        ret = PTR_ERR(rdev);
        goto anatop_probe_end;
    }

    platform_set_drvdata(pdev, rdev);

anatop_probe_end:
    if (ret)
        kfree(sreg->name);

    return ret;
}

static int __devexit anatop_regulator_remove(struct platform_device *pdev)
{
    struct regulator_dev *rdev = platform_get_drvdata(pdev);
    struct anatop_regulator *sreg = rdev_get_drvdata(rdev);
    const char *name = sreg->name;

    regulator_unregister(rdev);
    kfree(name);

    return 0;
}

static struct of_device_id __devinitdata of_anatop_regulator_match_tbl[] = {
    { .compatible = "fsl,anatop-regulator", },
    { /* end */ }
};

static struct platform_driver anatop_regulator_driver = {
    .driver = {
        .name   = "anatop_regulator",
        .owner  = THIS_MODULE,
        .of_match_table = of_anatop_regulator_match_tbl,
    },
    .probe  = anatop_regulator_probe,
    .remove = __devexit_p(anatop_regulator_remove),
};

static int __init anatop_regulator_init(void)
{
    return platform_driver_register(&anatop_regulator_driver);
}
postcore_initcall(anatop_regulator_init);

static void __exit anatop_regulator_exit(void)
{
    platform_driver_unregister(&anatop_regulator_driver);
}
module_exit(anatop_regulator_exit);

MODULE_AUTHOR("Nancy Chen <[email protected]>, "
          "Ying-Chun Liu (PaulLiu) <[email protected]>");
MODULE_DESCRIPTION("ANATOP Regulator driver");
MODULE_LICENSE("GPL v2");