root/drivers/media/spi/cxd2880-spi.c
// 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_sync 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 =
                        kzalloc(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_obj(struct cxd2880_dvb_spi);
        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_regulator;
                }
                dvb_spi->vcc_supply = NULL;
        } else {
                ret = regulator_enable(dvb_spi->vcc_supply);
                if (ret)
                        goto fail_regulator;
        }

        dvb_spi->spi = spi;
        mutex_init(&dvb_spi->spi_mutex);
        spi_set_drvdata(spi, 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("connect_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:
        if (dvb_spi->vcc_supply)
                regulator_disable(dvb_spi->vcc_supply);
fail_regulator:
        kfree(dvb_spi);
        return ret;
}

static void
cxd2880_spi_remove(struct spi_device *spi)
{
        struct cxd2880_dvb_spi *dvb_spi = spi_get_drvdata(spi);

        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");
}

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");