media: cxd2880-spi: Add support for CXD2880 SPI interface

This is the SPI adapter part of the driver for the
Sony CXD2880 DVB-T2/T tuner + demodulator.
Signed-off-by: Yasunari Takiguchi <Yasunari.Takiguchi@sony.com>
Signed-off-by: Masayuki Yamamoto <Masayuki.Yamamoto@sony.com>
Signed-off-by: Hideki Nozawa <Hideki.Nozawa@sony.com>
Signed-off-by: Kota Yonezawa <Kota.Yonezawa@sony.com>
Signed-off-by: Toshihiko Matsumoto <Toshihiko.Matsumoto@sony.com>
Signed-off-by: Satoshi Watanabe <Satoshi.C.Watanabe@sony.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

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/ktime.h>
+
+#include "dvb_demux.h"
+#include "dmxdev.h"
+#include "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;
+	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;
+	}
+
+	memset(&tx, 0, sizeof(tx));
+	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) {
+		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;
+
+	while (size > 0) {
+		send_data[1] = sub_address;
+		if (size > 255)
+			send_data[2] = 255;
+		else
+			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);
+			break;
+		}
+		sub_address += send_data[2];
+		write_data_top += send_data[2];
+		size -= send_data[2];
+	}
+
+	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);
+	memset(transfer, 0, sizeof(transfer));
+
+	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. Assumed bug.\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->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");
+		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);
+
+	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");