Linux preempt-rt

Check our new training course

Real-Time Linux with PREEMPT_RT

Check our new training course
with Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

/*
 * Copyright (c) 2016 Intel Corporation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <device.h>
#include <i2c.h>
#include <ioapic.h>

#include "qm_i2c.h"
#include "qm_scss.h"

/* Convenient macros to get the controller instance and the driver data. */
#define GET_CONTROLLER_INSTANCE(dev) \
	(((struct i2c_qmsi_config_info *)dev->config->config_info)->instance)
#define GET_DRIVER_DATA(dev) \
	((struct i2c_qmsi_driver_data *)dev->driver_data)

struct i2c_qmsi_config_info {
	qm_i2c_t instance; /* Controller instance. */
};

struct i2c_qmsi_driver_data {
	device_sync_call_t sync;
	qm_rc_t transfer_status;
};

static int i2c_qmsi_init(struct device *dev);

#ifdef CONFIG_I2C_QMSI_0

static struct i2c_qmsi_driver_data driver_data_0;

static struct i2c_qmsi_config_info config_info_0 = {
	.instance = QM_I2C_0,
};

DEVICE_INIT(i2c_0, CONFIG_I2C_QMSI_0_NAME, i2c_qmsi_init, &driver_data_0,
	    &config_info_0, SECONDARY, CONFIG_KERNEL_INIT_PRIORITY_DEVICE);

#endif /* CONFIG_I2C_QMSI_0 */

#ifdef CONFIG_I2C_QMSI_1

static struct i2c_qmsi_driver_data driver_data_1;

static struct i2c_qmsi_config_info config_info_1 = {
	.instance = QM_I2C_1,
};

DEVICE_INIT(i2c_1, CONFIG_I2C_QMSI_1_NAME, i2c_qmsi_init, &driver_data_1,
	    &config_info_1, SECONDARY, CONFIG_KERNEL_INIT_PRIORITY_DEVICE);

#endif /* CONFIG_I2C_QMSI_1 */

static int i2c_qmsi_configure(struct device *dev, uint32_t config)
{
	qm_i2c_t instance = GET_CONTROLLER_INSTANCE(dev);
	union dev_config cfg;
	qm_i2c_config_t qm_cfg;

	cfg.raw = config;

	/* This driver only supports master mode. */
	if (!cfg.bits.is_master_device)
		return DEV_INVALID_CONF;

	qm_cfg.mode = QM_I2C_MASTER;
	qm_cfg.address_mode = (cfg.bits.use_10_bit_addr) ? QM_I2C_10_BIT :
							   QM_I2C_7_BIT;

	switch (cfg.bits.speed) {
	case I2C_SPEED_STANDARD:
		qm_cfg.speed = QM_I2C_SPEED_STD;
		break;
	case I2C_SPEED_FAST:
		qm_cfg.speed = QM_I2C_SPEED_FAST;
		break;
	case QM_I2C_SPEED_FAST_PLUS:
		qm_cfg.speed = QM_I2C_SPEED_FAST_PLUS;
		break;
	default:
		return DEV_INVALID_CONF;
	}

	if (qm_i2c_set_config(instance, &qm_cfg) != QM_RC_OK)
		return DEV_FAIL;

	return DEV_OK;
}

static void transfer_complete(uint32_t id, qm_rc_t status)
{
	struct device *dev;
	struct i2c_qmsi_driver_data *driver_data;

	switch (id) {
#ifdef CONFIG_I2C_QMSI_0
	case QM_I2C_0:
		dev = DEVICE_GET(i2c_0);
		break;
#endif
#ifdef CONFIG_I2C_QMSI_1
	case QM_I2C_1:
		dev = DEVICE_GET(i2c_1);
		break;
#endif
	default:
		return;
	}

	driver_data = GET_DRIVER_DATA(dev);
	driver_data->transfer_status = status;
	device_sync_call_complete(&driver_data->sync);
}

static void complete_cb(uint32_t id, uint32_t len)
{
	transfer_complete(id, QM_RC_OK);
}

static void err_cb(uint32_t id, qm_i2c_status_t status)
{
	transfer_complete(id, status);
}

static int i2c_qmsi_transfer(struct device *dev, struct i2c_msg *msgs,
			     uint8_t num_msgs, uint16_t addr)
{
	struct i2c_qmsi_driver_data *driver_data = GET_DRIVER_DATA(dev);
	qm_i2c_t instance = GET_CONTROLLER_INSTANCE(dev);
	qm_rc_t rc;

	if (qm_i2c_get_status(instance) != QM_I2C_IDLE)
		return DEV_USED;

	if  (msgs == NULL || num_msgs == 0)
		return DEV_INVALID_OP;

	for (int i = 0; i < num_msgs; i++) {
		uint8_t *buf = msgs[i].buf;
		uint32_t len = msgs[i].len;
		uint8_t op =  msgs[i].flags & I2C_MSG_RW_MASK;
		bool stop = (msgs[i].flags & I2C_MSG_STOP) == I2C_MSG_STOP;
		qm_i2c_transfer_t xfer = { 0 };

		if (op == I2C_MSG_WRITE) {
			xfer.tx = buf;
			xfer.tx_len = len;
			xfer.tx_callback = complete_cb;
		} else {
			xfer.rx = buf;
			xfer.rx_len = len;
			xfer.rx_callback = complete_cb;
		}

		xfer.id = instance;
		xfer.stop = stop;
		xfer.err_callback = err_cb;

		rc = qm_i2c_master_irq_transfer(instance, &xfer, addr);
		if (rc != QM_RC_OK)
			return DEV_FAIL;

		/* Block current thread until the I2C transfer completes. */
		device_sync_call_wait(&driver_data->sync);

		if (driver_data->transfer_status != QM_RC_OK)
			return DEV_FAIL;
	}

	return DEV_OK;
}

static int i2c_qmsi_suspend(struct device *dev)
{
	return DEV_NO_SUPPORT;
}

static int i2c_qmsi_resume(struct device *dev)
{
	return DEV_NO_SUPPORT;
}

static struct i2c_driver_api api = {
	.configure = i2c_qmsi_configure,
	.transfer = i2c_qmsi_transfer,
	.suspend = i2c_qmsi_suspend,
	.resume = i2c_qmsi_resume,
};

static int i2c_qmsi_init(struct device *dev)
{
	struct i2c_qmsi_driver_data *driver_data = GET_DRIVER_DATA(dev);
	qm_i2c_t instance = GET_CONTROLLER_INSTANCE(dev);

	switch (instance) {
	case QM_I2C_0:
		/* Register interrupt handler, unmask IRQ and route it
		 * to Lakemont core.
		 */
		IRQ_CONNECT(CONFIG_I2C_QMSI_0_IRQ,
			    CONFIG_I2C_QMSI_0_INT_PRIORITY, qm_i2c_0_isr, NULL,
			    (IOAPIC_LEVEL | IOAPIC_HIGH));
		irq_enable(CONFIG_I2C_QMSI_0_IRQ);
		QM_SCSS_INT->int_i2c_mst_0_mask &= ~BIT(0);

		clk_periph_enable(CLK_PERIPH_I2C_M0_REGISTER);
		break;
	case QM_I2C_1:
		IRQ_CONNECT(CONFIG_I2C_QMSI_1_IRQ,
			    CONFIG_I2C_QMSI_1_INT_PRIORITY, qm_i2c_1_isr, NULL,
			    (IOAPIC_LEVEL | IOAPIC_HIGH));
		irq_enable(CONFIG_I2C_QMSI_1_IRQ);
		QM_SCSS_INT->int_i2c_mst_1_mask &= ~BIT(0);

		clk_periph_enable(CLK_PERIPH_I2C_M1_REGISTER);
		break;
	default:
		return DEV_FAIL;
	}

	device_sync_call_init(&driver_data->sync);

	dev->driver_api = &api;
	return DEV_OK;
}