soundwire: Add MIPI DisCo property helpers

MIPI Discovery And Configuration (DisCo) Specification for SoundWire
specifies properties to be implemented for SoundWire Masters and
Slaves. The DisCo spec doesn't mandate these properties. However,
SDW bus cannot work without knowing these values.

The helper functions read the Master and Slave properties.
Implementers of Master or Slave drivers can use any of the below
three mechanisms:
   a) Use these APIs here as .read_prop() callback for Master
      and Slave
   b) Implement own methods and set those as .read_prop(), but invoke
      APIs in this file for generic read and override the values with
      platform specific data
   c) Implement ones own methods which do not use anything provided
      here

Signed-off-by: Sanyog Kale <sanyog.r.kale@intel.com>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Acked-By: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 432 insertions, 2 deletions

diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
index c875e43..bcde0d2 100644
--- a/drivers/soundwire/Makefile
+++ b/drivers/soundwire/Makefile
@@ -3,5 +3,5 @@
 #
 
 #Bus Objs
-soundwire-bus-objs := bus_type.o bus.o slave.o
+soundwire-bus-objs := bus_type.o bus.o slave.o mipi_disco.o
 obj-$(CONFIG_SOUNDWIRE_BUS) += soundwire-bus.o
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index bc72c3d..9626bd1 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -25,6 +25,14 @@ int sdw_add_bus_master(struct sdw_bus *bus)
 	mutex_init(&bus->bus_lock);
 	INIT_LIST_HEAD(&bus->slaves);
 
+	if (bus->ops->read_prop) {
+		ret = bus->ops->read_prop(bus);
+		if (ret < 0) {
+			dev_err(bus->dev, "Bus read properties failed:%d", ret);
+			return ret;
+		}
+	}
+
 	/*
 	 * Device numbers in SoundWire are 0 thru 15. Enumeration device
 	 * number (0), Broadcast device number (15), Group numbers (12 and
diff --git a/drivers/soundwire/bus_type.c b/drivers/soundwire/bus_type.c
index 8d8dcc6..d5f3a70 100644
--- a/drivers/soundwire/bus_type.c
+++ b/drivers/soundwire/bus_type.c
@@ -77,6 +77,8 @@ static int sdw_drv_probe(struct device *dev)
 	if (!id)
 		return -ENODEV;
 
+	slave->ops = drv->ops;
+
 	/*
 	 * attach to power domain but don't turn on (last arg)
 	 */
@@ -89,7 +91,26 @@ static int sdw_drv_probe(struct device *dev)
 		}
 	}
 
-	return ret;
+	if (ret)
+		return ret;
+
+	/* device is probed so let's read the properties now */
+	if (slave->ops && slave->ops->read_prop)
+		slave->ops->read_prop(slave);
+
+	/*
+	 * Check for valid clk_stop_timeout, use DisCo worst case value of
+	 * 300ms
+	 *
+	 * TODO: check the timeouts and driver removal case
+	 */
+	if (slave->prop.clk_stop_timeout == 0)
+		slave->prop.clk_stop_timeout = 300;
+
+	slave->bus->clk_stop_timeout = max_t(u32, slave->bus->clk_stop_timeout,
+					slave->prop.clk_stop_timeout);
+
+	return 0;
 }
 
 static int sdw_drv_remove(struct device *dev)
diff --git a/drivers/soundwire/mipi_disco.c b/drivers/soundwire/mipi_disco.c
new file mode 100644
index 0000000..fdeba0c
--- /dev/null
+++ b/drivers/soundwire/mipi_disco.c
@@ -0,0 +1,401 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2015-17 Intel Corporation.
+
+/*
+ * MIPI Discovery And Configuration (DisCo) Specification for SoundWire
+ * specifies properties to be implemented for SoundWire Masters and Slaves.
+ * The DisCo spec doesn't mandate these properties. However, SDW bus cannot
+ * work without knowing these values.
+ *
+ * The helper functions read the Master and Slave properties. Implementers
+ * of Master or Slave drivers can use any of the below three mechanisms:
+ *    a) Use these APIs here as .read_prop() callback for Master and Slave
+ *    b) Implement own methods and set those as .read_prop(), but invoke
+ *    APIs in this file for generic read and override the values with
+ *    platform specific data
+ *    c) Implement ones own methods which do not use anything provided
+ *    here
+ */
+
+#include <linux/device.h>
+#include <linux/property.h>
+#include <linux/mod_devicetable.h>
+#include <linux/soundwire/sdw.h>
+#include "bus.h"
+
+/**
+ * sdw_master_read_prop() - Read Master properties
+ * @bus: SDW bus instance
+ */
+int sdw_master_read_prop(struct sdw_bus *bus)
+{
+	struct sdw_master_prop *prop = &bus->prop;
+	struct fwnode_handle *link;
+	char name[32];
+	int nval, i;
+
+	device_property_read_u32(bus->dev,
+			"mipi-sdw-sw-interface-revision", &prop->revision);
+
+	/* Find master handle */
+	snprintf(name, sizeof(name),
+			"mipi-sdw-master-%d-subproperties", bus->link_id);
+
+	link = device_get_named_child_node(bus->dev, name);
+	if (!link) {
+		dev_err(bus->dev, "Master node %s not found\n", name);
+		return -EIO;
+	}
+
+	if (fwnode_property_read_bool(link,
+			"mipi-sdw-clock-stop-mode0-supported") == true)
+		prop->clk_stop_mode = SDW_CLK_STOP_MODE0;
+
+	if (fwnode_property_read_bool(link,
+			"mipi-sdw-clock-stop-mode1-supported") == true)
+		prop->clk_stop_mode |= SDW_CLK_STOP_MODE1;
+
+	fwnode_property_read_u32(link,
+			"mipi-sdw-max-clock-frequency", &prop->max_freq);
+
+	nval = fwnode_property_read_u32_array(link,
+			"mipi-sdw-clock-frequencies-supported", NULL, 0);
+	if (nval > 0) {
+
+		prop->num_freq = nval;
+		prop->freq = devm_kcalloc(bus->dev, prop->num_freq,
+				sizeof(*prop->freq), GFP_KERNEL);
+		if (!prop->freq)
+			return -ENOMEM;
+
+		fwnode_property_read_u32_array(link,
+				"mipi-sdw-clock-frequencies-supported",
+				prop->freq, prop->num_freq);
+	}
+
+	/*
+	 * Check the frequencies supported. If FW doesn't provide max
+	 * freq, then populate here by checking values.
+	 */
+	if (!prop->max_freq && prop->freq) {
+		prop->max_freq = prop->freq[0];
+		for (i = 1; i < prop->num_freq; i++) {
+			if (prop->freq[i] > prop->max_freq)
+				prop->max_freq = prop->freq[i];
+		}
+	}
+
+	nval = fwnode_property_read_u32_array(link,
+			"mipi-sdw-supported-clock-gears", NULL, 0);
+	if (nval > 0) {
+
+		prop->num_clk_gears = nval;
+		prop->clk_gears = devm_kcalloc(bus->dev, prop->num_clk_gears,
+				sizeof(*prop->clk_gears), GFP_KERNEL);
+		if (!prop->clk_gears)
+			return -ENOMEM;
+
+		fwnode_property_read_u32_array(link,
+				"mipi-sdw-supported-clock-gears",
+				prop->clk_gears, prop->num_clk_gears);
+	}
+
+	fwnode_property_read_u32(link, "mipi-sdw-default-frame-rate",
+			&prop->default_frame_rate);
+
+	fwnode_property_read_u32(link, "mipi-sdw-default-frame-row-size",
+			&prop->default_row);
+
+	fwnode_property_read_u32(link, "mipi-sdw-default-frame-col-size",
+			&prop->default_col);
+
+	prop->dynamic_frame =  fwnode_property_read_bool(link,
+			"mipi-sdw-dynamic-frame-shape");
+
+	fwnode_property_read_u32(link, "mipi-sdw-command-error-threshold",
+			&prop->err_threshold);
+
+	return 0;
+}
+EXPORT_SYMBOL(sdw_master_read_prop);
+
+static int sdw_slave_read_dp0(struct sdw_slave *slave,
+		struct fwnode_handle *port, struct sdw_dp0_prop *dp0)
+{
+	int nval;
+
+	fwnode_property_read_u32(port, "mipi-sdw-port-max-wordlength",
+			&dp0->max_word);
+
+	fwnode_property_read_u32(port, "mipi-sdw-port-min-wordlength",
+			&dp0->min_word);
+
+	nval = fwnode_property_read_u32_array(port,
+			"mipi-sdw-port-wordlength-configs", NULL, 0);
+	if (nval > 0) {
+
+		dp0->num_words = nval;
+		dp0->words = devm_kcalloc(&slave->dev,
+				dp0->num_words, sizeof(*dp0->words),
+				GFP_KERNEL);
+		if (!dp0->words)
+			return -ENOMEM;
+
+		fwnode_property_read_u32_array(port,
+				"mipi-sdw-port-wordlength-configs",
+				dp0->words, dp0->num_words);
+	}
+
+	dp0->flow_controlled = fwnode_property_read_bool(
+			port, "mipi-sdw-bra-flow-controlled");
+
+	dp0->simple_ch_prep_sm = fwnode_property_read_bool(
+			port, "mipi-sdw-simplified-channel-prepare-sm");
+
+	dp0->device_interrupts = fwnode_property_read_bool(
+			port, "mipi-sdw-imp-def-dp0-interrupts-supported");
+
+	return 0;
+}
+
+static int sdw_slave_read_dpn(struct sdw_slave *slave,
+		struct sdw_dpn_prop *dpn, int count, int ports, char *type)
+{
+	struct fwnode_handle *node;
+	u32 bit, i = 0;
+	int nval;
+	unsigned long addr;
+	char name[40];
+
+	addr = ports;
+	/* valid ports are 1 to 14 so apply mask */
+	addr &= GENMASK(14, 1);
+
+	for_each_set_bit(bit, &addr, 32) {
+		snprintf(name, sizeof(name),
+			"mipi-sdw-dp-%d-%s-subproperties", bit, type);
+
+		dpn[i].num = bit;
+
+		node = device_get_named_child_node(&slave->dev, name);
+		if (!node) {
+			dev_err(&slave->dev, "%s dpN not found\n", name);
+			return -EIO;
+		}
+
+		fwnode_property_read_u32(node, "mipi-sdw-port-max-wordlength",
+					&dpn[i].max_word);
+		fwnode_property_read_u32(node, "mipi-sdw-port-min-wordlength",
+					&dpn[i].min_word);
+
+		nval = fwnode_property_read_u32_array(node,
+				"mipi-sdw-port-wordlength-configs", NULL, 0);
+		if (nval > 0) {
+
+			dpn[i].num_words = nval;
+			dpn[i].words = devm_kcalloc(&slave->dev,
+					dpn[i].num_words,
+					sizeof(*dpn[i].words), GFP_KERNEL);
+			if (!dpn[i].words)
+				return -ENOMEM;
+
+			fwnode_property_read_u32_array(node,
+					"mipi-sdw-port-wordlength-configs",
+					dpn[i].words, dpn[i].num_words);
+		}
+
+		fwnode_property_read_u32(node, "mipi-sdw-data-port-type",
+				&dpn[i].type);
+
+		fwnode_property_read_u32(node,
+				"mipi-sdw-max-grouping-supported",
+				&dpn[i].max_grouping);
+
+		dpn[i].simple_ch_prep_sm = fwnode_property_read_bool(node,
+				"mipi-sdw-simplified-channelprepare-sm");
+
+		fwnode_property_read_u32(node,
+				"mipi-sdw-port-channelprepare-timeout",
+				&dpn[i].ch_prep_timeout);
+
+		fwnode_property_read_u32(node,
+				"mipi-sdw-imp-def-dpn-interrupts-supported",
+				&dpn[i].device_interrupts);
+
+		fwnode_property_read_u32(node, "mipi-sdw-min-channel-number",
+				&dpn[i].min_ch);
+
+		fwnode_property_read_u32(node, "mipi-sdw-max-channel-number",
+				&dpn[i].max_ch);
+
+		nval = fwnode_property_read_u32_array(node,
+				"mipi-sdw-channel-number-list", NULL, 0);
+		if (nval > 0) {
+
+			dpn[i].num_ch = nval;
+			dpn[i].ch = devm_kcalloc(&slave->dev, dpn[i].num_ch,
+					sizeof(*dpn[i].ch), GFP_KERNEL);
+			if (!dpn[i].ch)
+				return -ENOMEM;
+
+			fwnode_property_read_u32_array(node,
+					"mipi-sdw-channel-number-list",
+					dpn[i].ch, dpn[i].num_ch);
+		}
+
+		nval = fwnode_property_read_u32_array(node,
+				"mipi-sdw-channel-combination-list", NULL, 0);
+		if (nval > 0) {
+
+			dpn[i].num_ch_combinations = nval;
+			dpn[i].ch_combinations = devm_kcalloc(&slave->dev,
+					dpn[i].num_ch_combinations,
+					sizeof(*dpn[i].ch_combinations),
+					GFP_KERNEL);
+			if (!dpn[i].ch_combinations)
+				return -ENOMEM;
+
+			fwnode_property_read_u32_array(node,
+					"mipi-sdw-channel-combination-list",
+					dpn[i].ch_combinations,
+					dpn[i].num_ch_combinations);
+		}
+
+		fwnode_property_read_u32(node,
+				"mipi-sdw-modes-supported", &dpn[i].modes);
+
+		fwnode_property_read_u32(node, "mipi-sdw-max-async-buffer",
+				&dpn[i].max_async_buffer);
+
+		dpn[i].block_pack_mode = fwnode_property_read_bool(node,
+				"mipi-sdw-block-packing-mode");
+
+		fwnode_property_read_u32(node, "mipi-sdw-port-encoding-type",
+				&dpn[i].port_encoding);
+
+		/* TODO: Read audio mode */
+
+		i++;
+	}
+
+	return 0;
+}
+
+/**
+ * sdw_slave_read_prop() - Read Slave properties
+ * @slave: SDW Slave
+ */
+int sdw_slave_read_prop(struct sdw_slave *slave)
+{
+	struct sdw_slave_prop *prop = &slave->prop;
+	struct device *dev = &slave->dev;
+	struct fwnode_handle *port;
+	int num_of_ports, nval, i, dp0 = 0;
+
+	device_property_read_u32(dev, "mipi-sdw-sw-interface-revision",
+				&prop->mipi_revision);
+
+	prop->wake_capable = device_property_read_bool(dev,
+				"mipi-sdw-wake-up-unavailable");
+	prop->wake_capable = !prop->wake_capable;
+
+	prop->test_mode_capable = device_property_read_bool(dev,
+				"mipi-sdw-test-mode-supported");
+
+	prop->clk_stop_mode1 = false;
+	if (device_property_read_bool(dev,
+				"mipi-sdw-clock-stop-mode1-supported"))
+		prop->clk_stop_mode1 = true;
+
+	prop->simple_clk_stop_capable = device_property_read_bool(dev,
+			"mipi-sdw-simplified-clockstopprepare-sm-supported");
+
+	device_property_read_u32(dev, "mipi-sdw-clockstopprepare-timeout",
+			&prop->clk_stop_timeout);
+
+	device_property_read_u32(dev, "mipi-sdw-slave-channelprepare-timeout",
+			&prop->ch_prep_timeout);
+
+	device_property_read_u32(dev,
+			"mipi-sdw-clockstopprepare-hard-reset-behavior",
+			&prop->reset_behave);
+
+	prop->high_PHY_capable = device_property_read_bool(dev,
+			"mipi-sdw-highPHY-capable");
+
+	prop->paging_support = device_property_read_bool(dev,
+			"mipi-sdw-paging-support");
+
+	prop->bank_delay_support = device_property_read_bool(dev,
+			"mipi-sdw-bank-delay-support");
+
+	device_property_read_u32(dev,
+			"mipi-sdw-port15-read-behavior", &prop->p15_behave);
+
+	device_property_read_u32(dev, "mipi-sdw-master-count",
+				&prop->master_count);
+
+	device_property_read_u32(dev, "mipi-sdw-source-port-list",
+				&prop->source_ports);
+
+	device_property_read_u32(dev, "mipi-sdw-sink-port-list",
+				&prop->sink_ports);
+
+	/* Read dp0 properties */
+	port = device_get_named_child_node(dev, "mipi-sdw-dp-0-subproperties");
+	if (!port) {
+		dev_dbg(dev, "DP0 node not found!!\n");
+	} else {
+
+		prop->dp0_prop = devm_kzalloc(&slave->dev,
+				sizeof(*prop->dp0_prop), GFP_KERNEL);
+		if (!prop->dp0_prop)
+			return -ENOMEM;
+
+		sdw_slave_read_dp0(slave, port, prop->dp0_prop);
+		dp0 = 1;
+	}
+
+	/*
+	 * Based on each DPn port, get source and sink dpn properties.
+	 * Also, some ports can operate as both source or sink.
+	 */
+
+	/* Allocate memory for set bits in port lists */
+	nval = hweight32(prop->source_ports);
+	prop->src_dpn_prop = devm_kcalloc(&slave->dev, nval,
+				sizeof(*prop->src_dpn_prop), GFP_KERNEL);
+	if (!prop->src_dpn_prop)
+		return -ENOMEM;
+
+	/* Read dpn properties for source port(s) */
+	sdw_slave_read_dpn(slave, prop->src_dpn_prop, nval,
+			prop->source_ports, "source");
+
+	nval = hweight32(prop->sink_ports);
+	prop->sink_dpn_prop = devm_kcalloc(&slave->dev, nval,
+				sizeof(*prop->sink_dpn_prop), GFP_KERNEL);
+	if (!prop->sink_dpn_prop)
+		return -ENOMEM;
+
+	/* Read dpn properties for sink port(s) */
+	sdw_slave_read_dpn(slave, prop->sink_dpn_prop, nval,
+			prop->sink_ports, "sink");
+
+	/* some ports are bidirectional so check total ports by ORing */
+	nval = prop->source_ports | prop->sink_ports;
+	num_of_ports = hweight32(nval) + dp0; /* add DP0 */
+
+	/* Allocate port_ready based on num_of_ports */
+	slave->port_ready = devm_kcalloc(&slave->dev, num_of_ports,
+				sizeof(*slave->port_ready), GFP_KERNEL);
+	if (!slave->port_ready)
+		return -ENOMEM;
+
+	/* Initialize completion */
+	for (i = 0; i < num_of_ports; i++)
+		init_completion(&slave->port_ready[i]);
+
+	return 0;
+}
+EXPORT_SYMBOL(sdw_slave_read_prop);