linux/linux-5.4.31/drivers/media/pci/cx88/cx88-vp3054-i2c.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * cx88-vp3054-i2c.c -- support for the secondary I2C bus of the
 *			DNTV Live! DVB-T Pro (VP-3054), wired as:
 *			GPIO[0] -> SCL, GPIO[1] -> SDA
 *
 * (c) 2005 Chris Pascoe <c.pascoe@itee.uq.edu.au>
 */

#include "cx88.h"
#include "cx88-vp3054-i2c.h"

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

MODULE_DESCRIPTION("driver for cx2388x VP3054 design");
MODULE_AUTHOR("Chris Pascoe <c.pascoe@itee.uq.edu.au>");
MODULE_LICENSE("GPL");

/* ----------------------------------------------------------------------- */

static void vp3054_bit_setscl(void *data, int state)
{
	struct cx8802_dev *dev = data;
	struct cx88_core *core = dev->core;
	struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;

	if (state) {
		vp3054_i2c->state |=  0x0001;	/* SCL high */
		vp3054_i2c->state &= ~0x0100;	/* external pullup */
	} else {
		vp3054_i2c->state &= ~0x0001;	/* SCL low */
		vp3054_i2c->state |=  0x0100;	/* drive pin */
	}
	cx_write(MO_GP0_IO, 0x010000 | vp3054_i2c->state);
	cx_read(MO_GP0_IO);
}

static void vp3054_bit_setsda(void *data, int state)
{
	struct cx8802_dev *dev = data;
	struct cx88_core *core = dev->core;
	struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;

	if (state) {
		vp3054_i2c->state |=  0x0002;	/* SDA high */
		vp3054_i2c->state &= ~0x0200;	/* tristate pin */
	} else {
		vp3054_i2c->state &= ~0x0002;	/* SDA low */
		vp3054_i2c->state |=  0x0200;	/* drive pin */
	}
	cx_write(MO_GP0_IO, 0x020000 | vp3054_i2c->state);
	cx_read(MO_GP0_IO);
}

static int vp3054_bit_getscl(void *data)
{
	struct cx8802_dev *dev = data;
	struct cx88_core *core = dev->core;
	u32 state;

	state = cx_read(MO_GP0_IO);
	return (state & 0x01) ? 1 : 0;
}

static int vp3054_bit_getsda(void *data)
{
	struct cx8802_dev *dev = data;
	struct cx88_core *core = dev->core;
	u32 state;

	state = cx_read(MO_GP0_IO);
	return (state & 0x02) ? 1 : 0;
}

/* ----------------------------------------------------------------------- */

static const struct i2c_algo_bit_data vp3054_i2c_algo_template = {
	.setsda  = vp3054_bit_setsda,
	.setscl  = vp3054_bit_setscl,
	.getsda  = vp3054_bit_getsda,
	.getscl  = vp3054_bit_getscl,
	.udelay  = 16,
	.timeout = 200,
};

/* ----------------------------------------------------------------------- */

int vp3054_i2c_probe(struct cx8802_dev *dev)
{
	struct cx88_core *core = dev->core;
	struct vp3054_i2c_state *vp3054_i2c;
	int rc;

	if (core->boardnr != CX88_BOARD_DNTV_LIVE_DVB_T_PRO)
		return 0;

	vp3054_i2c = kzalloc(sizeof(*vp3054_i2c), GFP_KERNEL);
	if (!vp3054_i2c)
		return -ENOMEM;
	dev->vp3054 = vp3054_i2c;

	vp3054_i2c->algo = vp3054_i2c_algo_template;

	vp3054_i2c->adap.dev.parent = &dev->pci->dev;
	strscpy(vp3054_i2c->adap.name, core->name,
		sizeof(vp3054_i2c->adap.name));
	vp3054_i2c->adap.owner = THIS_MODULE;
	vp3054_i2c->algo.data = dev;
	i2c_set_adapdata(&vp3054_i2c->adap, dev);
	vp3054_i2c->adap.algo_data = &vp3054_i2c->algo;

	vp3054_bit_setscl(dev, 1);
	vp3054_bit_setsda(dev, 1);

	rc = i2c_bit_add_bus(&vp3054_i2c->adap);
	if (rc != 0) {
		pr_err("vp3054_i2c register FAILED\n");

		kfree(dev->vp3054);
		dev->vp3054 = NULL;
	}

	return rc;
}
EXPORT_SYMBOL(vp3054_i2c_probe);

void vp3054_i2c_remove(struct cx8802_dev *dev)
{
	struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;

	if (!vp3054_i2c ||
	    dev->core->boardnr != CX88_BOARD_DNTV_LIVE_DVB_T_PRO)
		return;

	i2c_del_adapter(&vp3054_i2c->adap);
	kfree(vp3054_i2c);
}
EXPORT_SYMBOL(vp3054_i2c_remove);