// SPDX-License-Identifier: GPL-2.0
/*
 * cxd2880-spi.c
 * Sony CXD2880 DVB-T2/T tuner + demodulator driver
 * SPI adapter
 *
 * Copyright (C) 2016, 2017, 2018 Sony Semiconductor Solutions Corporation
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__

#include <linux/spi/spi.h>
#include <linux/regulator/consumer.h>
#include <linux/ktime.h>

#include <media/dvb_demux.h>
#include <media/dmxdev.h>
#include <media/dvb_frontend.h>
#include "cxd2880.h"

#define CXD2880_MAX_FILTER_SIZE 32
#define BURST_WRITE_MAX 128
#define MAX_TRANS_PKT 300

struct cxd2880_ts_buf_info {
	u8 read_ready:1;
	u8 almost_full:1;
	u8 almost_empty:1;
	u8 overflow:1;
	u8 underflow:1;
	u16 pkt_num;
};

struct cxd2880_pid_config {
	u8 is_enable;
	u16 pid;
};

struct cxd2880_pid_filter_config {
	u8 is_negative;
	struct cxd2880_pid_config pid_config[CXD2880_MAX_FILTER_SIZE];
};

struct cxd2880_dvb_spi {
	struct dvb_frontend dvb_fe;
	struct dvb_adapter adapter;
	struct dvb_demux demux;
	struct dmxdev dmxdev;
	struct dmx_frontend dmx_fe;
	struct task_struct *cxd2880_ts_read_thread;
	struct spi_device *spi;
	struct mutex spi_mutex; /* For SPI access exclusive control */
	int feed_count;
	int all_pid_feed_count;
	struct regulator *vcc_supply;
	u8 *ts_buf;
	struct cxd2880_pid_filter_config filter_config;
};

DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);

static int cxd2880_write_spi(struct spi_device *spi, u8 *data, u32 size)
{
	struct spi_message msg;
	struct spi_transfer tx = {};

	if (!spi || !data) {
		pr_err("invalid arg\n");
		return -EINVAL;
	}

	tx.tx_buf = data;
	tx.len = size;

	spi_message_init(&msg);
	spi_message_add_tail(&tx, &msg);

	return spi_sync(spi, &msg);
}

static int cxd2880_write_reg(struct spi_device *spi,
			     u8 sub_address, const u8 *data, u32 size)
{
	u8 send_data[BURST_WRITE_MAX + 4];
	const u8 *write_data_top = NULL;
	int ret = 0;

	if (!spi || !data) {
		pr_err("invalid arg\n");
		return -EINVAL;
	}
	if (size > BURST_WRITE_MAX || size > U8_MAX) {
		pr_err("data size > WRITE_MAX\n");
		return -EINVAL;
	}

	if (sub_address + size > 0x100) {
		pr_err("out of range\n");
		return -EINVAL;
	}

	send_data[0] = 0x0e;
	write_data_top = data;

	send_data[1] = sub_address;
	send_data[2] = (u8)size;

	memcpy(&send_data[3], write_data_top, send_data[2]);

	ret = cxd2880_write_spi(spi, send_data, send_data[2] + 3);
	if (ret)
		pr_err("write spi failed %d\n", ret);

	return ret;
}

static int cxd2880_spi_read_ts(struct spi_device *spi,
			       u8 *read_data,
			       u32 packet_num)
{
	int ret;
	u8 data[3];
	struct spi_message message;
	struct spi_transfer transfer[2] = {};

	if (!spi || !read_data || !packet_num) {
		pr_err("invalid arg\n");
		return -EINVAL;
	}
	if (packet_num > 0xffff) {
		pr_err("packet num > 0xffff\n");
		return -EINVAL;
	}

	data[0] = 0x10;
	data[1] = packet_num >> 8;
	data[2] = packet_num;

	spi_message_init(&message);

	transfer[0].len = 3;
	transfer[0].tx_buf = data;
	spi_message_add_tail(&transfer[0], &message);
	transfer[1].len = packet_num * 188;
	transfer[1].rx_buf = read_data;
	spi_message_add_tail(&transfer[1], &message);

	ret = spi_sync(spi, &message);
	if (ret)
		pr_err("spi_write_then_read failed\n");

	return ret;
}

static int cxd2880_spi_read_ts_buffer_info(struct spi_device *spi,
					   struct cxd2880_ts_buf_info *info)
{
	u8 send_data = 0x20;
	u8 recv_data[2];
	int ret;

	if (!spi || !info) {
		pr_err("invalid arg\n");
		return -EINVAL;
	}

	ret = spi_write_then_read(spi, &send_data, 1,
				  recv_data, sizeof(recv_data));
	if (ret)
		pr_err("spi_write_then_read failed\n");

	info->read_ready = (recv_data[0] & 0x80) ? 1 : 0;
	info->almost_full = (recv_data[0] & 0x40) ? 1 : 0;
	info->almost_empty = (recv_data[0] & 0x20) ? 1 : 0;
	info->overflow = (recv_data[0] & 0x10) ? 1 : 0;
	info->underflow = (recv_data[0] & 0x08) ? 1 : 0;
	info->pkt_num = ((recv_data[0] & 0x07) << 8) | recv_data[1];

	return ret;
}

static int cxd2880_spi_clear_ts_buffer(struct spi_device *spi)
{
	u8 data = 0x03;
	int ret;

	ret = cxd2880_write_spi(spi, &data, 1);

	if (ret)
		pr_err("write spi failed\n");

	return ret;
}

static int cxd2880_set_pid_filter(struct spi_device *spi,
				  struct cxd2880_pid_filter_config *cfg)
{
	u8 data[65];
	int i;
	u16 pid = 0;
	int ret;

	if (!spi) {
		pr_err("invalid arg\n");
		return -EINVAL;
	}

	data[0] = 0x00;
	ret = cxd2880_write_reg(spi, 0x00, &data[0], 1);
	if (ret)
		return ret;
	if (!cfg) {
		data[0] = 0x02;
		ret = cxd2880_write_reg(spi, 0x50, &data[0], 1);
	} else {
		data[0] = cfg->is_negative ? 0x01 : 0x00;

		for (i = 0; i < CXD2880_MAX_FILTER_SIZE; i++) {
			pid = cfg->pid_config[i].pid;
			if (cfg->pid_config[i].is_enable) {
				data[1 + (i * 2)] = (pid >> 8) | 0x20;
				data[2 + (i * 2)] = pid & 0xff;
			} else {
				data[1 + (i * 2)] = 0x00;
				data[2 + (i * 2)] = 0x00;
			}
		}
		ret = cxd2880_write_reg(spi, 0x50, data, 65);
	}

	return ret;
}

static int cxd2880_update_pid_filter(struct cxd2880_dvb_spi *dvb_spi,
				     struct cxd2880_pid_filter_config *cfg,
				     bool is_all_pid_filter)
{
	int ret;

	if (!dvb_spi || !cfg) {
		pr_err("invalid arg.\n");
		return -EINVAL;
	}

	mutex_lock(&dvb_spi->spi_mutex);
	if (is_all_pid_filter) {
		struct cxd2880_pid_filter_config tmpcfg;

		memset(&tmpcfg, 0, sizeof(tmpcfg));
		tmpcfg.is_negative = 1;
		tmpcfg.pid_config[0].is_enable = 1;
		tmpcfg.pid_config[0].pid = 0x1fff;

		ret = cxd2880_set_pid_filter(dvb_spi->spi, &tmpcfg);
	} else {
		ret = cxd2880_set_pid_filter(dvb_spi->spi, cfg);
	}
	mutex_unlock(&dvb_spi->spi_mutex);

	if (ret)
		pr_err("set_pid_filter failed\n");

	return ret;
}

static int cxd2880_ts_read(void *arg)
{
	struct cxd2880_dvb_spi *dvb_spi = NULL;
	struct cxd2880_ts_buf_info info;
	ktime_t start;
	u32 i;
	int ret;

	dvb_spi = arg;
	if (!dvb_spi) {
		pr_err("invalid arg\n");
		return -EINVAL;
	}

	ret = cxd2880_spi_clear_ts_buffer(dvb_spi->spi);
	if (ret) {
		pr_err("set_clear_ts_buffer failed\n");
		return ret;
	}

	start = ktime_get();
	while (!kthread_should_stop()) {
		ret = cxd2880_spi_read_ts_buffer_info(dvb_spi->spi,
						      &info);
		if (ret) {
			pr_err("spi_read_ts_buffer_info error\n");
			return ret;
		}

		if (info.pkt_num > MAX_TRANS_PKT) {
			for (i = 0; i < info.pkt_num / MAX_TRANS_PKT; i++) {
				cxd2880_spi_read_ts(dvb_spi->spi,
						    dvb_spi->ts_buf,
						    MAX_TRANS_PKT);
				dvb_dmx_swfilter(&dvb_spi->demux,
						 dvb_spi->ts_buf,
						 MAX_TRANS_PKT * 188);
			}
			start = ktime_get();
		} else if ((info.pkt_num > 0) &&
			   (ktime_to_ms(ktime_sub(ktime_get(), start)) >= 500)) {
			cxd2880_spi_read_ts(dvb_spi->spi,
					    dvb_spi->ts_buf,
					    info.pkt_num);
			dvb_dmx_swfilter(&dvb_spi->demux,
					 dvb_spi->ts_buf,
					 info.pkt_num * 188);
			start = ktime_get();
		} else {
			usleep_range(10000, 11000);
		}
	}

	return 0;
}

static int cxd2880_start_feed(struct dvb_demux_feed *feed)
{
	int ret = 0;
	int i = 0;
	struct dvb_demux *demux = NULL;
	struct cxd2880_dvb_spi *dvb_spi = NULL;

	if (!feed) {
		pr_err("invalid arg\n");
		return -EINVAL;
	}

	demux = feed->demux;
	if (!demux) {
		pr_err("feed->demux is NULL\n");
		return -EINVAL;
	}
	dvb_spi = demux->priv;

	if (dvb_spi->feed_count == CXD2880_MAX_FILTER_SIZE) {
		pr_err("Exceeded maximum PID count (32).");
		pr_err("Selected PID cannot be enabled.\n");
		return -EINVAL;
	}

	if (feed->pid == 0x2000) {
		if (dvb_spi->all_pid_feed_count == 0) {
			ret = cxd2880_update_pid_filter(dvb_spi,
							&dvb_spi->filter_config,
							true);
			if (ret) {
				pr_err("update pid filter failed\n");
				return ret;
			}
		}
		dvb_spi->all_pid_feed_count++;

		pr_debug("all PID feed (count = %d)\n",
			 dvb_spi->all_pid_feed_count);
	} else {
		struct cxd2880_pid_filter_config cfgtmp;

		cfgtmp = dvb_spi->filter_config;

		for (i = 0; i < CXD2880_MAX_FILTER_SIZE; i++) {
			if (cfgtmp.pid_config[i].is_enable == 0) {
				cfgtmp.pid_config[i].is_enable = 1;
				cfgtmp.pid_config[i].pid = feed->pid;
				pr_debug("store PID %d to #%d\n",
					 feed->pid, i);
				break;
			}
		}
		if (i == CXD2880_MAX_FILTER_SIZE) {
			pr_err("PID filter is full.\n");
			return -EINVAL;
		}
		if (!dvb_spi->all_pid_feed_count)
			ret = cxd2880_update_pid_filter(dvb_spi,
							&cfgtmp,
							false);
		if (ret)
			return ret;

		dvb_spi->filter_config = cfgtmp;
	}

	if (dvb_spi->feed_count == 0) {
		dvb_spi->ts_buf =
			kmalloc(MAX_TRANS_PKT * 188,
				GFP_KERNEL | GFP_DMA);
		if (!dvb_spi->ts_buf) {
			pr_err("ts buffer allocate failed\n");
			memset(&dvb_spi->filter_config, 0,
			       sizeof(dvb_spi->filter_config));
			dvb_spi->all_pid_feed_count = 0;
			return -ENOMEM;
		}
		dvb_spi->cxd2880_ts_read_thread = kthread_run(cxd2880_ts_read,
							      dvb_spi,
							      "cxd2880_ts_read");
		if (IS_ERR(dvb_spi->cxd2880_ts_read_thread)) {
			pr_err("kthread_run failed/\n");
			kfree(dvb_spi->ts_buf);
			dvb_spi->ts_buf = NULL;
			memset(&dvb_spi->filter_config, 0,
			       sizeof(dvb_spi->filter_config));
			dvb_spi->all_pid_feed_count = 0;
			return PTR_ERR(dvb_spi->cxd2880_ts_read_thread);
		}
	}

	dvb_spi->feed_count++;

	pr_debug("start feed (count %d)\n", dvb_spi->feed_count);
	return 0;
}

static int cxd2880_stop_feed(struct dvb_demux_feed *feed)
{
	int i = 0;
	int ret;
	struct dvb_demux *demux = NULL;
	struct cxd2880_dvb_spi *dvb_spi = NULL;

	if (!feed) {
		pr_err("invalid arg\n");
		return -EINVAL;
	}

	demux = feed->demux;
	if (!demux) {
		pr_err("feed->demux is NULL\n");
		return -EINVAL;
	}
	dvb_spi = demux->priv;

	if (!dvb_spi->feed_count) {
		pr_err("no feed is started\n");
		return -EINVAL;
	}

	if (feed->pid == 0x2000) {
		/*
		 * Special PID case.
		 * Number of 0x2000 feed request was stored
		 * in dvb_spi->all_pid_feed_count.
		 */
		if (dvb_spi->all_pid_feed_count <= 0) {
			pr_err("PID %d not found.\n", feed->pid);
			return -EINVAL;
		}
		dvb_spi->all_pid_feed_count--;
	} else {
		struct cxd2880_pid_filter_config cfgtmp;

		cfgtmp = dvb_spi->filter_config;

		for (i = 0; i < CXD2880_MAX_FILTER_SIZE; i++) {
			if (feed->pid == cfgtmp.pid_config[i].pid &&
			    cfgtmp.pid_config[i].is_enable != 0) {
				cfgtmp.pid_config[i].is_enable = 0;
				cfgtmp.pid_config[i].pid = 0;
				pr_debug("removed PID %d from #%d\n",
					 feed->pid, i);
				break;
			}
		}
		dvb_spi->filter_config = cfgtmp;

		if (i == CXD2880_MAX_FILTER_SIZE) {
			pr_err("PID %d not found\n", feed->pid);
			return -EINVAL;
		}
	}

	ret = cxd2880_update_pid_filter(dvb_spi,
					&dvb_spi->filter_config,
					dvb_spi->all_pid_feed_count > 0);
	dvb_spi->feed_count--;

	if (dvb_spi->feed_count == 0) {
		int ret_stop = 0;

		ret_stop = kthread_stop(dvb_spi->cxd2880_ts_read_thread);
		if (ret_stop) {
			pr_err("'kthread_stop failed. (%d)\n", ret_stop);
			ret = ret_stop;
		}
		kfree(dvb_spi->ts_buf);
		dvb_spi->ts_buf = NULL;
	}

	pr_debug("stop feed ok.(count %d)\n", dvb_spi->feed_count);

	return ret;
}

static const struct of_device_id cxd2880_spi_of_match[] = {
	{ .compatible = "sony,cxd2880" },
	{ /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, cxd2880_spi_of_match);

static int
cxd2880_spi_probe(struct spi_device *spi)
{
	int ret;
	struct cxd2880_dvb_spi *dvb_spi = NULL;
	struct cxd2880_config config;

	if (!spi) {
		pr_err("invalid arg.\n");
		return -EINVAL;
	}

	dvb_spi = kzalloc(sizeof(struct cxd2880_dvb_spi), GFP_KERNEL);
	if (!dvb_spi)
		return -ENOMEM;

	dvb_spi->vcc_supply = devm_regulator_get_optional(&spi->dev, "vcc");
	if (IS_ERR(dvb_spi->vcc_supply)) {
		if (PTR_ERR(dvb_spi->vcc_supply) == -EPROBE_DEFER) {
			ret = -EPROBE_DEFER;
			goto fail_adapter;
		}
		dvb_spi->vcc_supply = NULL;
	} else {
		ret = regulator_enable(dvb_spi->vcc_supply);
		if (ret)
			goto fail_adapter;
	}

	dvb_spi->spi = spi;
	mutex_init(&dvb_spi->spi_mutex);
	dev_set_drvdata(&spi->dev, dvb_spi);
	config.spi = spi;
	config.spi_mutex = &dvb_spi->spi_mutex;

	ret = dvb_register_adapter(&dvb_spi->adapter,
				   "CXD2880",
				   THIS_MODULE,
				   &spi->dev,
				   adapter_nr);
	if (ret < 0) {
		pr_err("dvb_register_adapter() failed\n");
		goto fail_adapter;
	}

	if (!dvb_attach(cxd2880_attach, &dvb_spi->dvb_fe, &config)) {
		pr_err("cxd2880_attach failed\n");
		ret = -ENODEV;
		goto fail_attach;
	}

	ret = dvb_register_frontend(&dvb_spi->adapter,
				    &dvb_spi->dvb_fe);
	if (ret < 0) {
		pr_err("dvb_register_frontend() failed\n");
		goto fail_frontend;
	}

	dvb_spi->demux.dmx.capabilities = DMX_TS_FILTERING;
	dvb_spi->demux.priv = dvb_spi;
	dvb_spi->demux.filternum = CXD2880_MAX_FILTER_SIZE;
	dvb_spi->demux.feednum = CXD2880_MAX_FILTER_SIZE;
	dvb_spi->demux.start_feed = cxd2880_start_feed;
	dvb_spi->demux.stop_feed = cxd2880_stop_feed;

	ret = dvb_dmx_init(&dvb_spi->demux);
	if (ret < 0) {
		pr_err("dvb_dmx_init() failed\n");
		goto fail_dmx;
	}

	dvb_spi->dmxdev.filternum = CXD2880_MAX_FILTER_SIZE;
	dvb_spi->dmxdev.demux = &dvb_spi->demux.dmx;
	dvb_spi->dmxdev.capabilities = 0;
	ret = dvb_dmxdev_init(&dvb_spi->dmxdev,
			      &dvb_spi->adapter);
	if (ret < 0) {
		pr_err("dvb_dmxdev_init() failed\n");
		goto fail_dmxdev;
	}

	dvb_spi->dmx_fe.source = DMX_FRONTEND_0;
	ret = dvb_spi->demux.dmx.add_frontend(&dvb_spi->demux.dmx,
					      &dvb_spi->dmx_fe);
	if (ret < 0) {
		pr_err("add_frontend() failed\n");
		goto fail_dmx_fe;
	}

	ret = dvb_spi->demux.dmx.connect_frontend(&dvb_spi->demux.dmx,
						  &dvb_spi->dmx_fe);
	if (ret < 0) {
		pr_err("dvb_register_frontend() failed\n");
		goto fail_fe_conn;
	}

	pr_info("Sony CXD2880 has successfully attached.\n");

	return 0;

fail_fe_conn:
	dvb_spi->demux.dmx.remove_frontend(&dvb_spi->demux.dmx,
					   &dvb_spi->dmx_fe);
fail_dmx_fe:
	dvb_dmxdev_release(&dvb_spi->dmxdev);
fail_dmxdev:
	dvb_dmx_release(&dvb_spi->demux);
fail_dmx:
	dvb_unregister_frontend(&dvb_spi->dvb_fe);
fail_frontend:
	dvb_frontend_detach(&dvb_spi->dvb_fe);
fail_attach:
	dvb_unregister_adapter(&dvb_spi->adapter);
fail_adapter:
	kfree(dvb_spi);
	return ret;
}

static int
cxd2880_spi_remove(struct spi_device *spi)
{
	struct cxd2880_dvb_spi *dvb_spi;

	if (!spi) {
		pr_err("invalid arg\n");
		return -EINVAL;
	}

	dvb_spi = dev_get_drvdata(&spi->dev);

	if (!dvb_spi) {
		pr_err("failed\n");
		return -EINVAL;
	}
	dvb_spi->demux.dmx.remove_frontend(&dvb_spi->demux.dmx,
					   &dvb_spi->dmx_fe);
	dvb_dmxdev_release(&dvb_spi->dmxdev);
	dvb_dmx_release(&dvb_spi->demux);
	dvb_unregister_frontend(&dvb_spi->dvb_fe);
	dvb_frontend_detach(&dvb_spi->dvb_fe);
	dvb_unregister_adapter(&dvb_spi->adapter);

	if (dvb_spi->vcc_supply)
		regulator_disable(dvb_spi->vcc_supply);

	kfree(dvb_spi);
	pr_info("cxd2880_spi remove ok.\n");

	return 0;
}

static const struct spi_device_id cxd2880_spi_id[] = {
	{ "cxd2880", 0 },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(spi, cxd2880_spi_id);

static struct spi_driver cxd2880_spi_driver = {
	.driver	= {
		.name	= "cxd2880",
		.of_match_table = cxd2880_spi_of_match,
	},
	.id_table = cxd2880_spi_id,
	.probe    = cxd2880_spi_probe,
	.remove   = cxd2880_spi_remove,
};
module_spi_driver(cxd2880_spi_driver);

MODULE_DESCRIPTION("Sony CXD2880 DVB-T2/T tuner + demod driver SPI adapter");
MODULE_AUTHOR("Sony Semiconductor Solutions Corporation");
MODULE_LICENSE("GPL v2");