xref: /openbmc/linux/drivers/media/pci/ngene/ngene-i2c.c (revision 75bf465f0bc33e9b776a46d6a1b9b990f5fb7c37)

// SPDX-License-Identifier: GPL-2.0-only
/*
 * ngene-i2c.c: nGene PCIe bridge driver i2c functions
 *
 * Copyright (C) 2005-2007 Micronas
 *
 * Copyright (C) 2008-2009 Ralph Metzler <rjkm@metzlerbros.de>
 *                         Modifications for new nGene firmware,
 *                         support for EEPROM-copying,
 *                         support for new dual DVB-S2 card prototype
 */

/* FIXME - some of these can probably be removed */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/io.h>
#include <asm/div64.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/timer.h>
#include <linux/byteorder/generic.h>
#include <linux/firmware.h>
#include <linux/vmalloc.h>

#include "ngene.h"

/* Firmware command for i2c operations */
static int ngene_command_i2c_read(struct ngene *dev, u8 adr,
			   u8 *out, u8 outlen, u8 *in, u8 inlen, int flag)
{
	struct ngene_command com;

	com.cmd.hdr.Opcode = CMD_I2C_READ;
	com.cmd.hdr.Length = outlen + 3;
	com.cmd.I2CRead.Device = adr << 1;
	memcpy(com.cmd.I2CRead.Data, out, outlen);
	com.cmd.I2CRead.Data[outlen] = inlen;
	com.cmd.I2CRead.Data[outlen + 1] = 0;
	com.in_len = outlen + 3;
	com.out_len = inlen + 1;

	if (ngene_command(dev, &com) < 0)
		return -EIO;

	if ((com.cmd.raw8[0] >> 1) != adr)
		return -EIO;

	if (flag)
		memcpy(in, com.cmd.raw8, inlen + 1);
	else
		memcpy(in, com.cmd.raw8 + 1, inlen);
	return 0;
}

static int ngene_command_i2c_write(struct ngene *dev, u8 adr,
				   u8 *out, u8 outlen)
{
	struct ngene_command com;


	com.cmd.hdr.Opcode = CMD_I2C_WRITE;
	com.cmd.hdr.Length = outlen + 1;
	com.cmd.I2CRead.Device = adr << 1;
	memcpy(com.cmd.I2CRead.Data, out, outlen);
	com.in_len = outlen + 1;
	com.out_len = 1;

	if (ngene_command(dev, &com) < 0)
		return -EIO;

	if (com.cmd.raw8[0] == 1)
		return -EIO;

	return 0;
}

static void ngene_i2c_set_bus(struct ngene *dev, int bus)
{
	if (!(dev->card_info->i2c_access & 2))
		return;
	if (dev->i2c_current_bus == bus)
		return;

	switch (bus) {
	case 0:
		ngene_command_gpio_set(dev, 3, 0);
		ngene_command_gpio_set(dev, 2, 1);
		break;

	case 1:
		ngene_command_gpio_set(dev, 2, 0);
		ngene_command_gpio_set(dev, 3, 1);
		break;
	}
	dev->i2c_current_bus = bus;
}

static int ngene_i2c_master_xfer(struct i2c_adapter *adapter,
				 struct i2c_msg msg[], int num)
{
	struct ngene_channel *chan =
		(struct ngene_channel *)i2c_get_adapdata(adapter);
	struct ngene *dev = chan->dev;

	mutex_lock(&dev->i2c_switch_mutex);
	ngene_i2c_set_bus(dev, chan->number);

	if (num == 2 && msg[1].flags & I2C_M_RD && !(msg[0].flags & I2C_M_RD))
		if (!ngene_command_i2c_read(dev, msg[0].addr,
					    msg[0].buf, msg[0].len,
					    msg[1].buf, msg[1].len, 0))
			goto done;

	if (num == 1 && !(msg[0].flags & I2C_M_RD))
		if (!ngene_command_i2c_write(dev, msg[0].addr,
					     msg[0].buf, msg[0].len))
			goto done;
	if (num == 1 && (msg[0].flags & I2C_M_RD))
		if (!ngene_command_i2c_read(dev, msg[0].addr, NULL, 0,
					    msg[0].buf, msg[0].len, 0))
			goto done;

	mutex_unlock(&dev->i2c_switch_mutex);
	return -EIO;

done:
	mutex_unlock(&dev->i2c_switch_mutex);
	return num;
}


static u32 ngene_i2c_functionality(struct i2c_adapter *adap)
{
	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}

static const struct i2c_algorithm ngene_i2c_algo = {
	.master_xfer = ngene_i2c_master_xfer,
	.functionality = ngene_i2c_functionality,
};

int ngene_i2c_init(struct ngene *dev, int dev_nr)
{
	struct i2c_adapter *adap = &(dev->channel[dev_nr].i2c_adapter);

	i2c_set_adapdata(adap, &(dev->channel[dev_nr]));

	strscpy(adap->name, "nGene", sizeof(adap->name));

	adap->algo = &ngene_i2c_algo;
	adap->algo_data = (void *)&(dev->channel[dev_nr]);
	adap->dev.parent = &dev->pci_dev->dev;

	return i2c_add_adapter(adap);
}