[alsa-devel] [PATCH 1/2] ASoC: hw-params-rules: add generic hw_params-rules
kernel at martin.sperl.org
kernel at martin.sperl.org
Fri May 20 14:30:44 CEST 2016
From: Martin Sperl <kernel at martin.sperl.org>
Add generic rules that may execute when running hw_params
methods.
These rules are configured via the device-tree.
Right now only a static list of match and action rules exist.
This can get changed in the future to something more dynamic
if security concerns can get handled propperly.
Signed-off-by: Martin Sperl <kernel at martin.sperl.org>
---
.../devicetree/bindings/sound/hw-params-rules.txt | 86 +++++
sound/soc/generic/Kconfig | 6 +
sound/soc/generic/Makefile | 2 +
sound/soc/generic/hw-params-rules.c | 402 +++++++++++++++++++++
sound/soc/generic/hw-params-rules.h | 49 +++
5 files changed, 545 insertions(+)
create mode 100644 Documentation/devicetree/bindings/sound/hw-params-rules.txt
create mode 100644 sound/soc/generic/hw-params-rules.c
create mode 100644 sound/soc/generic/hw-params-rules.h
diff --git a/Documentation/devicetree/bindings/sound/hw-params-rules.txt b/Documentation/devicetree/bindings/sound/hw-params-rules.txt
new file mode 100644
index 0000000..8e5f2b5
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/hw-params-rules.txt
@@ -0,0 +1,86 @@
+HW-params-rules:
+
+Rules that execute actions during hw-params method calls.
+
+The following optional nodes will sit inside the sound card nodes:
+
+hw-params-rule subnodes:
+
+Required properties:
+- priority: the priority of the rule - lowest is applied first.
+
+contains further subnodes:
+
+- match: list of matches that have to apply
+- action: list of actions to execute
+
+match and action subnodes:
+
+Required properties:
+
+- method: the method name (string) to execute
+
+Possible values for method:
+* asoc_generic_hw_params_match_sample_bits
+* asoc_generic_hw_params_match_rate
+* asoc_generic_hw_params_match_channel
+* asoc_generic_hw_params_set_fixed_bclk_size
+
+
+Required/optional properties depend on the method defined
+typical properies:
+
+- value: u32 value to pass to method.
+- values: u32 value array to pass to method.
+
+Example:
+sound {
+ compatible = "simple-audio-card";
+ ...
+ /*
+ * set bclk_size to 80 when encountering:
+ * 48kHz or 96kHz with 2 channels with 32bit/channel
+ */
+ hw-params-rule at 0 {
+ priority = <0>;
+ match at 0 {
+ method = "asoc_generic_hw_params_match_sample_bits";
+ values = <32>;
+ };
+ match at 1 {
+ method = "asoc_generic_hw_params_match_rate";
+ values = <48000>, <96000>;
+ };
+ match at 2 {
+ method = "asoc_generic_hw_params_match_channels";
+ values = <2>;
+ };
+ action at 0 {
+ method = "asoc_generic_hw_params_set_fixed_bclk_size";
+ value = <80>;
+ };
+ };
+ /*
+ * set bclk_size to 40 when encountering:
+ * 48kHz with 2 channels with 16bit/channel
+ */
+ hw-params-rule at 1 {
+ priority = <1>;
+ match at 0 {
+ method = "asoc_generic_hw_params_match_sample_bits";
+ values = <16>;
+ };
+ match at 1 {
+ method = "asoc_generic_hw_params_match_rate";
+ values = <48000>;
+ };
+ match at 2 {
+ method = "asoc_generic_hw_params_match_channels";
+ values = <2>;
+ };
+ action at 0 {
+ method = "asoc_generic_hw_params_set_fixed_bclk_size";
+ value = <40>;
+ };
+ };
+};
diff --git a/sound/soc/generic/Kconfig b/sound/soc/generic/Kconfig
index 610f612..2c9f0c1 100644
--- a/sound/soc/generic/Kconfig
+++ b/sound/soc/generic/Kconfig
@@ -1,3 +1,9 @@
+config SND_HW_PARAMS_RULES
+ tristate "ASoC hw_param rules support"
+ depends on OF
+ help
+ This option enables generic hw_param_rules support
+
config SND_SIMPLE_CARD
tristate "ASoC Simple sound card support"
help
diff --git a/sound/soc/generic/Makefile b/sound/soc/generic/Makefile
index 9c3b246..4eaad07 100644
--- a/sound/soc/generic/Makefile
+++ b/sound/soc/generic/Makefile
@@ -1,3 +1,5 @@
snd-soc-simple-card-objs := simple-card.o
+snd-soc-hw-params-rules-objs := hw-params-rules.o
obj-$(CONFIG_SND_SIMPLE_CARD) += snd-soc-simple-card.o
+obj-$(CONFIG_SND_HW_PARAMS_RULES) += snd-soc-hw-params-rules.o
diff --git a/sound/soc/generic/hw-params-rules.c b/sound/soc/generic/hw-params-rules.c
new file mode 100644
index 0000000..46dbdff
--- /dev/null
+++ b/sound/soc/generic/hw-params-rules.c
@@ -0,0 +1,402 @@
+/*
+ * ASoC generic hw_params_rules support
+ *
+ * Copyright (C) 2016 Martin Sperl
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/list_sort.h>
+#include <sound/pcm_params.h>
+#include <sound/simple_card.h>
+#include <sound/soc-dai.h>
+#include <sound/soc.h>
+
+struct snd_soc_hw_params_actionmatch {
+ struct list_head list;
+ int (*method)(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ void *data);
+ void *data;
+};
+
+struct snd_soc_hw_param_rule {
+ struct list_head list;
+ const char *name;
+ u32 priority;
+ struct list_head matches;
+ struct list_head actions;
+};
+
+struct snd_soc_size_u32array {
+ size_t size;
+ u32 data[];
+};
+
+static int asoc_generic_hw_params_read_u32array(
+ struct device *dev, struct device_node *node, void **data)
+{
+ int i, size, ret;
+ struct snd_soc_size_u32array *array;
+
+ size = of_property_count_elems_of_size(node, "values", sizeof(u32));
+ if (size < 0) {
+ dev_err(dev,
+ "%s: Could not read size of property \"values\" - %d\n",
+ of_node_full_name(node), size);
+ return size;
+ }
+
+ array = devm_kzalloc(dev, sizeof(*array) + sizeof(u32) * size,
+ GFP_KERNEL);
+ if (!array)
+ return -ENOMEM;
+ *data = array;
+
+ array->size = size;
+
+ for (i = 0; i < size; i++) {
+ ret = of_property_read_u32(node, "values", &array->data[i]);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int asoc_generic_hw_params_read_u32(
+ struct device *dev, struct device_node *node, void **data)
+{
+ return of_property_read_u32(node, "value", (u32 *)data);
+}
+
+static int asoc_generic_hw_params_match_sample_bits(
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ void *data)
+{
+ long int bits =
+ snd_pcm_format_physical_width(params_format(params));
+ struct snd_soc_size_u32array *array = data;
+ int i;
+
+ for (i = 0; i < array->size; i++) {
+ if (bits == array->data[i])
+ return 1;
+ }
+
+ return 0;
+}
+
+static int asoc_generic_hw_params_match_channels(
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ void *data)
+{
+ int channels = params_channels(params);
+ struct snd_soc_size_u32array *array = data;
+ int i;
+
+ for (i = 0; i < array->size; i++) {
+ if (channels == array->data[i])
+ return 1;
+ }
+
+ return 0;
+}
+
+static int asoc_generic_hw_params_match_rate(
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ void *data)
+{
+ long int rate = params_rate(params);
+
+ struct snd_soc_size_u32array *array = data;
+ int i;
+
+ for (i = 0; i < array->size; i++) {
+ if (rate == array->data[i])
+ return 1;
+ }
+
+ return 0;
+}
+
+static int asoc_generic_hw_params_set_fixed_bclk_size(
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ void *data)
+{
+ struct snd_soc_pcm_runtime *rtd = substream->private_data;
+ struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+
+ return snd_soc_dai_set_bclk_ratio(cpu_dai, (unsigned int)data);
+}
+
+struct asoc_generic_hw_params_method {
+ const char *name;
+ int (*method)(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ void *data);
+ int (*parse)(struct device *dev, struct device_node *node,
+ void **data);
+};
+
+#define HW_PARAMS_METHOD(m, p) \
+ {.name = #m, .method = m, .parse = p }
+#define HW_PARAMS_METHOD_U32(n) \
+ HW_PARAMS_METHOD(n, asoc_generic_hw_params_read_u32)
+#define HW_PARAMS_METHOD_U32ARRAY(n) \
+ HW_PARAMS_METHOD(n, asoc_generic_hw_params_read_u32array)
+
+static const struct asoc_generic_hw_params_method
+asoc_generic_hw_params_methods[] = {
+ HW_PARAMS_METHOD_U32ARRAY(asoc_generic_hw_params_match_sample_bits),
+ HW_PARAMS_METHOD_U32ARRAY(asoc_generic_hw_params_match_rate),
+ HW_PARAMS_METHOD_U32ARRAY(asoc_generic_hw_params_match_channels),
+ HW_PARAMS_METHOD_U32(asoc_generic_hw_params_set_fixed_bclk_size)
+};
+
+static int asoc_generic_hw_params_lookup_methods(
+ struct device *dev, const char *method,
+ struct device_node *node,
+ struct snd_soc_hw_params_actionmatch *am)
+{
+ const struct asoc_generic_hw_params_method *m;
+ size_t i;
+
+ /*
+ * hardcoded list of "allowed" methods
+ * maybe a more dynamic approach using kallsyms could also be taken
+ */
+ for (i = 0; i < ARRAY_SIZE(asoc_generic_hw_params_methods); i++) {
+ m = &asoc_generic_hw_params_methods[i];
+ if (strcmp(m->name, method) == 0) {
+ am->method = m->method;
+ if (m->parse)
+ return m->parse(dev, node, &am->data);
+ else
+ return 0;
+ }
+ }
+
+ dev_err(dev, "%s: method %s not found\n",
+ of_node_full_name(node), method);
+ return -EINVAL;
+}
+
+static int asoc_generic_hw_params_handle_rule(
+ struct snd_soc_hw_param_rule *rule,
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ struct snd_soc_pcm_runtime *rtd = substream->private_data;
+ struct device *dev = rtd->dev;
+ struct snd_soc_hw_params_actionmatch *am;
+ int ret;
+
+ dev_dbg(dev, "Trying to apply rule: %s\n", rule->name);
+
+ /* apply match rules */
+ list_for_each_entry(am, &rule->matches, list) {
+ dev_dbg(dev, "\tRunning match %pf(%pK)\n",
+ am->method, am->data);
+ /* match method return 0 on match, 1 otherwise */
+ ret = am->method(substream, params, am->data);
+ if (!ret)
+ return 1;
+ }
+
+ /* so we match, so run all the actions */
+ list_for_each_entry(am, &rule->actions, list) {
+ dev_dbg(dev, "\tRunning action %pf(%pK)\n",
+ am->method, am->data);
+ /* action method returns 0 on success */
+ ret = am->method(substream, params, am->data);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+int asoc_generic_hw_params_process_rules(
+ struct list_head *list_head,
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ struct snd_soc_hw_param_rule *rule;
+ int ret;
+
+ /* check if the list_head is initialized */
+ if (!list_head->next)
+ return 0;
+
+ /* iterate all rules */
+ list_for_each_entry(rule, list_head, list) {
+ ret = asoc_generic_hw_params_handle_rule(
+ rule, substream, params);
+ if (ret <= 0)
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(asoc_generic_hw_params_process_rules);
+
+static int asoc_generic_hw_params_actionmatch_parse_of(
+ struct device *dev, struct device_node *node,
+ struct list_head *list_head, const char *nodename)
+{
+ struct snd_soc_hw_params_actionmatch *am;
+ const char *methodname;
+ int ret;
+
+ /* get the method name */
+ ret = of_property_read_string(node, "method", &methodname);
+ if (ret) {
+ dev_err(dev, "%s: missing \"method\" property - %d\n",
+ of_node_full_name(node), ret);
+ return ret;
+ }
+
+ /* alloc the action/match */
+ am = devm_kzalloc(dev, sizeof(*am), GFP_KERNEL);
+ if (!am)
+ return -ENOMEM;
+
+ /* lookup the method */
+ ret = asoc_generic_hw_params_lookup_methods(dev, methodname,
+ node, am);
+ if (ret)
+ return ret;
+
+ /* append to list */
+ list_add_tail(&am->list, list_head);
+
+ dev_dbg(dev, "\t\tadded %s: %s - %pf(%pK)\n", nodename,
+ of_node_full_name(node), am->method, am->data);
+
+ return 0;
+}
+
+static int asoc_generic_hw_params_actionmatches_parse_of(
+ struct device *dev, struct device_node *node,
+ struct list_head *list_head, const char *nodename)
+{
+ struct device_node *np = NULL;
+ int ret = 0;
+
+ /* init matchers */
+ INIT_LIST_HEAD(list_head);
+
+ /* iterate over all child nodes */
+ for_each_child_of_node(node, np) {
+ if (np->name && (of_node_cmp(np->name, nodename) == 0)) {
+ ret = asoc_generic_hw_params_actionmatch_parse_of(
+ dev, np, list_head, nodename);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static int asoc_generic_hw_params_rule_parse_of(
+ struct device *dev, struct device_node *node,
+ struct list_head *list_head)
+{
+ struct snd_soc_hw_param_rule *rule;
+ int ret;
+
+ rule = devm_kzalloc(dev, sizeof(*rule), GFP_KERNEL);
+ if (!rule)
+ return -ENOMEM;
+
+ rule->name = of_node_full_name(node);
+
+ dev_dbg(dev, "\tadding Rule: %s\n", rule->name);
+
+ /* read priority */
+ ret = of_property_read_u32(node, "priority", &rule->priority);
+ if (ret) {
+ dev_err(dev, "%s: can not read \"priority\" - %d\n",
+ rule->name, ret);
+ return ret;
+ }
+
+ /* parse all matches sub-nodes */
+ ret = asoc_generic_hw_params_actionmatches_parse_of(
+ dev, node, &rule->matches, "match");
+ if (ret)
+ return ret;
+
+ /* parse all action sub-nodes */
+ ret = asoc_generic_hw_params_actionmatches_parse_of(
+ dev, node, &rule->actions, "action");
+ if (ret)
+ return ret;
+
+ /* append to list */
+ list_add_tail(&rule->list, list_head);
+
+ return 0;
+}
+
+static int asoc_generic_hw_params_rules_sort(
+ void *data, struct list_head *a, struct list_head *b)
+{
+ struct snd_soc_hw_param_rule *rulea =
+ container_of(a, typeof(*rulea), list);
+ struct snd_soc_hw_param_rule *ruleb =
+ container_of(b, typeof(*ruleb), list);
+
+ if (rulea->priority < ruleb->priority)
+ return -1;
+ if (rulea->priority > ruleb->priority)
+ return 1;
+
+ return 0;
+}
+
+int asoc_generic_hw_params_rules_parse_of(
+ struct device *dev,
+ struct device_node *node,
+ struct list_head *list_head)
+{
+ const char *nodename = "hw-params-rule";
+ struct device_node *np = NULL;
+ int ret = 0;
+
+ /* init matchers */
+ INIT_LIST_HEAD(list_head);
+
+ if (!of_get_child_by_name(node, nodename))
+ return 0;
+
+ for (np = of_find_node_by_name(node, nodename); np;
+ np = of_find_node_by_name(np, nodename)) {
+ ret = asoc_generic_hw_params_rule_parse_of(
+ dev, np, list_head);
+ if (ret)
+ return ret;
+ }
+
+ /* and sort by name */
+ list_sort(dev, list_head, asoc_generic_hw_params_rules_sort);
+
+ /* iterate the sub-nodes */
+ return 0;
+}
+EXPORT_SYMBOL_GPL(asoc_generic_hw_params_rules_parse_of);
+
+MODULE_AUTHOR("Martin Sperl");
+MODULE_DESCRIPTION("generic hw_params_rules support");
+MODULE_LICENSE("GPL");
diff --git a/sound/soc/generic/hw-params-rules.h b/sound/soc/generic/hw-params-rules.h
new file mode 100644
index 0000000..0b054ce
--- /dev/null
+++ b/sound/soc/generic/hw-params-rules.h
@@ -0,0 +1,49 @@
+/*
+ * ASoC generic hw_params_rules support
+ *
+ * Copyright (C) 2016 Martin Sperl
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __HW_PARAMS_RULES_H
+#define __HW_PARAMS_RULES_H
+
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/of.h>
+#include <sound/pcm.h>
+
+#if defined(CONFIG_SND_HW_PARAMS_RULES) || \
+ defined(CONFIG_SND_HW_PARAMS_RULES_MODULE)
+
+int asoc_generic_hw_params_rules_parse_of(
+ struct device *dev,
+ struct device_node *node,
+ struct list_head *list_head);
+
+int asoc_generic_hw_params_process_rules(
+ struct list_head *list_head,
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params);
+#else
+static int asoc_generic_hw_params_rules_parse_of(
+ struct device *dev,
+ struct device_node *node,
+ struct list_head *list_head)
+{
+ return 0;
+}
+
+static int asoc_generic_hw_params_process_rules(
+ struct list_head *list_head,
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ return 0;
+}
+#endif
+
+#endif
--
2.1.4
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