From: Martin Sperl kernel@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@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@0 { + priority = <0>; + match@0 { + method = "asoc_generic_hw_params_match_sample_bits"; + values = <32>; + }; + match@1 { + method = "asoc_generic_hw_params_match_rate"; + values = <48000>, <96000>; + }; + match@2 { + method = "asoc_generic_hw_params_match_channels"; + values = <2>; + }; + action@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@1 { + priority = <1>; + match@0 { + method = "asoc_generic_hw_params_match_sample_bits"; + values = <16>; + }; + match@1 { + method = "asoc_generic_hw_params_match_rate"; + values = <48000>; + }; + match@2 { + method = "asoc_generic_hw_params_match_channels"; + values = <2>; + }; + action@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