root/drivers/media/pci/ddbridge/ddbridge-i2c.c
// SPDX-License-Identifier: GPL-2.0
/*
 * ddbridge-i2c.c: Digital Devices bridge i2c driver
 *
 * Copyright (C) 2010-2017 Digital Devices GmbH
 *                         Ralph Metzler <rjkm@metzlerbros.de>
 *                         Marcus Metzler <mocm@metzlerbros.de>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/io.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/timer.h>
#include <linux/i2c.h>
#include <linux/swab.h>
#include <linux/vmalloc.h>

#include "ddbridge.h"
#include "ddbridge-i2c.h"
#include "ddbridge-regs.h"
#include "ddbridge-io.h"

/******************************************************************************/

static int ddb_i2c_cmd(struct ddb_i2c *i2c, u32 adr, u32 cmd)
{
        struct ddb *dev = i2c->dev;
        unsigned long stat;
        u32 val;

        ddbwritel(dev, (adr << 9) | cmd, i2c->regs + I2C_COMMAND);
        stat = wait_for_completion_timeout(&i2c->completion, HZ);
        val = ddbreadl(dev, i2c->regs + I2C_COMMAND);
        if (stat == 0) {
                dev_err(dev->dev, "I2C timeout, card %d, port %d, link %u\n",
                        dev->nr, i2c->nr, i2c->link);
                {
                        u32 istat = ddbreadl(dev, INTERRUPT_STATUS);

                        dev_err(dev->dev, "DDBridge IRS %08x\n", istat);
                        if (i2c->link) {
                                u32 listat = ddbreadl(dev,
                                        DDB_LINK_TAG(i2c->link) |
                                        INTERRUPT_STATUS);

                                dev_err(dev->dev, "DDBridge link %u IRS %08x\n",
                                        i2c->link, listat);
                        }
                        if (istat & 1) {
                                ddbwritel(dev, istat & 1, INTERRUPT_ACK);
                        } else {
                                u32 mon = ddbreadl(dev,
                                        i2c->regs + I2C_MONITOR);

                                dev_err(dev->dev, "I2C cmd=%08x mon=%08x\n",
                                        val, mon);
                        }
                }
                return -EIO;
        }
        val &= 0x70000;
        if (val == 0x20000)
                dev_err(dev->dev, "I2C bus error\n");
        if (val)
                return -EIO;
        return 0;
}

static int ddb_i2c_master_xfer(struct i2c_adapter *adapter,
                               struct i2c_msg msg[], int num)
{
        struct ddb_i2c *i2c = (struct ddb_i2c *)i2c_get_adapdata(adapter);
        struct ddb *dev = i2c->dev;
        u8 addr = 0;

        addr = msg[0].addr;
        if (msg[0].len > i2c->bsize)
                return -EIO;
        switch (num) {
        case 1:
                if (msg[0].flags & I2C_M_RD) {
                        ddbwritel(dev, msg[0].len << 16,
                                  i2c->regs + I2C_TASKLENGTH);
                        if (ddb_i2c_cmd(i2c, addr, 3))
                                break;
                        ddbcpyfrom(dev, msg[0].buf,
                                   i2c->rbuf, msg[0].len);
                        return num;
                }
                ddbcpyto(dev, i2c->wbuf, msg[0].buf, msg[0].len);
                ddbwritel(dev, msg[0].len, i2c->regs + I2C_TASKLENGTH);
                if (ddb_i2c_cmd(i2c, addr, 2))
                        break;
                return num;
        case 2:
                if ((msg[0].flags & I2C_M_RD) == I2C_M_RD)
                        break;
                if ((msg[1].flags & I2C_M_RD) != I2C_M_RD)
                        break;
                if (msg[1].len > i2c->bsize)
                        break;
                ddbcpyto(dev, i2c->wbuf, msg[0].buf, msg[0].len);
                ddbwritel(dev, msg[0].len | (msg[1].len << 16),
                          i2c->regs + I2C_TASKLENGTH);
                if (ddb_i2c_cmd(i2c, addr, 1))
                        break;
                ddbcpyfrom(dev, msg[1].buf,
                           i2c->rbuf,
                           msg[1].len);
                return num;
        default:
                break;
        }
        return -EIO;
}

static u32 ddb_i2c_functionality(struct i2c_adapter *adap)
{
        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}

static const struct i2c_algorithm ddb_i2c_algo = {
        .master_xfer   = ddb_i2c_master_xfer,
        .functionality = ddb_i2c_functionality,
};

void ddb_i2c_release(struct ddb *dev)
{
        int i;
        struct ddb_i2c *i2c;

        for (i = 0; i < dev->i2c_num; i++) {
                i2c = &dev->i2c[i];
                i2c_del_adapter(&i2c->adap);
        }
}

static void i2c_handler(void *priv)
{
        struct ddb_i2c *i2c = (struct ddb_i2c *)priv;

        complete(&i2c->completion);
}

static int ddb_i2c_add(struct ddb *dev, struct ddb_i2c *i2c,
                       const struct ddb_regmap *regmap, int link,
                       int i, int num)
{
        struct i2c_adapter *adap;

        i2c->nr = i;
        i2c->dev = dev;
        i2c->link = link;
        i2c->bsize = regmap->i2c_buf->size;
        i2c->wbuf = DDB_LINK_TAG(link) |
                (regmap->i2c_buf->base + i2c->bsize * i);
        i2c->rbuf = i2c->wbuf; /* + i2c->bsize / 2 */
        i2c->regs = DDB_LINK_TAG(link) |
                (regmap->i2c->base + regmap->i2c->size * i);
        ddbwritel(dev, I2C_SPEED_100, i2c->regs + I2C_TIMING);
        ddbwritel(dev, ((i2c->rbuf & 0xffff) << 16) | (i2c->wbuf & 0xffff),
                  i2c->regs + I2C_TASKADDRESS);
        init_completion(&i2c->completion);

        adap = &i2c->adap;
        i2c_set_adapdata(adap, i2c);
#ifdef I2C_ADAP_CLASS_TV_DIGITAL
        adap->class = I2C_ADAP_CLASS_TV_DIGITAL | I2C_CLASS_TV_ANALOG;
#else
#ifdef I2C_CLASS_TV_ANALOG
        adap->class = I2C_CLASS_TV_ANALOG;
#endif
#endif
        snprintf(adap->name, I2C_NAME_SIZE, "ddbridge_%02x.%x.%x",
                 dev->nr, i2c->link, i);
        adap->algo = &ddb_i2c_algo;
        adap->algo_data = (void *)i2c;
        adap->dev.parent = dev->dev;
        return i2c_add_adapter(adap);
}

int ddb_i2c_init(struct ddb *dev)
{
        int stat = 0;
        u32 i, j, num = 0, l, base;
        struct ddb_i2c *i2c;
        struct i2c_adapter *adap;
        const struct ddb_regmap *regmap;

        for (l = 0; l < DDB_MAX_LINK; l++) {
                if (!dev->link[l].info)
                        continue;
                regmap = dev->link[l].info->regmap;
                if (!regmap || !regmap->i2c)
                        continue;
                base = regmap->irq_base_i2c;
                for (i = 0; i < regmap->i2c->num; i++) {
                        if (!(dev->link[l].info->i2c_mask & (1 << i)))
                                continue;
                        i2c = &dev->i2c[num];
                        ddb_irq_set(dev, l, i + base, i2c_handler, i2c);
                        stat = ddb_i2c_add(dev, i2c, regmap, l, i, num);
                        if (stat)
                                break;
                        num++;
                }
        }
        if (stat) {
                for (j = 0; j < num; j++) {
                        i2c = &dev->i2c[j];
                        adap = &i2c->adap;
                        i2c_del_adapter(adap);
                }
        } else {
                dev->i2c_num = num;
        }

        return stat;
}