// SPDX-License-Identifier: GPL-2.0
//
// Driver for LNB supply and control IC STMicroelectronics LNBH29
//
// Copyright (c) 2018 Socionext Inc.

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>

#include <media/dvb_frontend.h>
#include "lnbh29.h"

/**
 * struct lnbh29_priv - LNBH29 driver private data
 * @i2c:         Pointer to the I2C adapter structure
 * @i2c_address: I2C address of LNBH29 chip
 * @config:      Registers configuration
 *               offset 0: 1st register address, always 0x01 (DATA)
 *               offset 1: DATA register value
 */
struct lnbh29_priv {
        struct i2c_adapter *i2c;
        u8 i2c_address;
        u8 config[2];
};

#define LNBH29_STATUS_OLF     BIT(0)
#define LNBH29_STATUS_OTF     BIT(1)
#define LNBH29_STATUS_VMON    BIT(2)
#define LNBH29_STATUS_PNG     BIT(3)
#define LNBH29_STATUS_PDO     BIT(4)
#define LNBH29_VSEL_MASK      GENMASK(2, 0)
#define LNBH29_VSEL_0         0x00
/* Min: 13.188V, Typ: 13.667V, Max:14V */
#define LNBH29_VSEL_13        0x03
/* Min: 18.158V, Typ: 18.817V, Max:19.475V */
#define LNBH29_VSEL_18        0x07

static int lnbh29_read_vmon(struct lnbh29_priv *priv)
{
        u8 addr = 0x00;
        u8 status[2];
        int ret;
        struct i2c_msg msg[2] = {
                {
                        .addr = priv->i2c_address,
                        .flags = 0,
                        .len = 1,
                        .buf = &addr
                }, {
                        .addr = priv->i2c_address,
                        .flags = I2C_M_RD,
                        .len = sizeof(status),
                        .buf = status
                }
        };

        ret = i2c_transfer(priv->i2c, msg, 2);
        if (ret >= 0 && ret != 2)
                ret = -EIO;
        if (ret < 0) {
                dev_dbg(&priv->i2c->dev, "LNBH29 I2C transfer failed (%d)\n",
                        ret);
                return ret;
        }

        if (status[0] & (LNBH29_STATUS_OLF | LNBH29_STATUS_VMON)) {
                dev_err(&priv->i2c->dev,
                        "LNBH29 voltage in failure state, status reg 0x%x\n",
                        status[0]);
                return -EIO;
        }

        return 0;
}

static int lnbh29_set_voltage(struct dvb_frontend *fe,
                              enum fe_sec_voltage voltage)
{
        struct lnbh29_priv *priv = fe->sec_priv;
        u8 data_reg;
        int ret;
        struct i2c_msg msg = {
                .addr = priv->i2c_address,
                .flags = 0,
                .len = sizeof(priv->config),
                .buf = priv->config
        };

        switch (voltage) {
        case SEC_VOLTAGE_OFF:
                data_reg = LNBH29_VSEL_0;
                break;
        case SEC_VOLTAGE_13:
                data_reg = LNBH29_VSEL_13;
                break;
        case SEC_VOLTAGE_18:
                data_reg = LNBH29_VSEL_18;
                break;
        default:
                return -EINVAL;
        }
        priv->config[1] &= ~LNBH29_VSEL_MASK;
        priv->config[1] |= data_reg;

        ret = i2c_transfer(priv->i2c, &msg, 1);
        if (ret >= 0 && ret != 1)
                ret = -EIO;
        if (ret < 0) {
                dev_err(&priv->i2c->dev, "LNBH29 I2C transfer error (%d)\n",
                        ret);
                return ret;
        }

        /* Soft-start time (Vout 0V to 18V) is Typ. 6ms. */
        usleep_range(6000, 20000);

        if (voltage == SEC_VOLTAGE_OFF)
                return 0;

        return lnbh29_read_vmon(priv);
}

static void lnbh29_release(struct dvb_frontend *fe)
{
        lnbh29_set_voltage(fe, SEC_VOLTAGE_OFF);
        kfree(fe->sec_priv);
        fe->sec_priv = NULL;
}

struct dvb_frontend *lnbh29_attach(struct dvb_frontend *fe,
                                   struct lnbh29_config *cfg,
                                   struct i2c_adapter *i2c)
{
        struct lnbh29_priv *priv;

        priv = kzalloc_obj(*priv);
        if (!priv)
                return NULL;

        priv->i2c_address = (cfg->i2c_address >> 1);
        priv->i2c = i2c;
        priv->config[0] = 0x01;
        priv->config[1] = cfg->data_config;
        fe->sec_priv = priv;

        if (lnbh29_set_voltage(fe, SEC_VOLTAGE_OFF)) {
                dev_err(&i2c->dev, "no LNBH29 found at I2C addr 0x%02x\n",
                        priv->i2c_address);
                kfree(priv);
                fe->sec_priv = NULL;
                return NULL;
        }

        fe->ops.release_sec = lnbh29_release;
        fe->ops.set_voltage = lnbh29_set_voltage;

        dev_info(&i2c->dev, "LNBH29 attached at I2C addr 0x%02x\n",
                 priv->i2c_address);

        return fe;
}
EXPORT_SYMBOL(lnbh29_attach);

MODULE_AUTHOR("Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>");
MODULE_DESCRIPTION("STMicroelectronics LNBH29 driver");
MODULE_LICENSE("GPL v2");