ASoC: SDCA: Parse initialization write table

Each SDCA Function may contain a table of register writes that should be
written out before the Function is used. Add code to parse this table
from the DisCo tables in ACPI.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Link: https://patch.msgid.link/20250205113801.3699902-4-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/include/sound/sdca_function.h b/include/sound/sdca_function.h
index 3f4031d285d631a386ef3af8029226c2cd72b89f..47fc1da8e4f3323ff45b5b4e0bc9b0cfcc43a388 100644 (file)
--- a/include/sound/sdca_function.h
+++ b/include/sound/sdca_function.h
@@ -10,6 +10,7 @@
 #define __SDCA_FUNCTION_H__
 
 #include <linux/bits.h>
+#include <linux/types.h>
 
 struct device;
 struct sdca_function_desc;
@@ -20,6 +21,11 @@ struct sdca_function_desc;
  */
 #define SDCA_MAX_ENTITY_COUNT 128
 
+/*
+ * Sanity check on number of initialization writes, can be expanded if needed.
+ */
+#define SDCA_MAX_INIT_COUNT 2048
+
 /**
  * enum sdca_function_type - SDCA Function Type codes
  * @SDCA_FUNCTION_TYPE_SMART_AMP: Amplifier with protection features.
@@ -65,6 +71,16 @@ enum sdca_function_type {
 #define        SDCA_FUNCTION_TYPE_HID_NAME                     "HID"
 #define        SDCA_FUNCTION_TYPE_IMP_DEF_NAME                 "ImplementationDefined"
 
+/**
+ * struct sdca_init_write - a single initialization write
+ * @addr: Register address to be written
+ * @val: Single byte value to be written
+ */
+struct sdca_init_write {
+       u32 addr;
+       u8 val;
+};
+
 /**
  * enum sdca_entity0_controls - SDCA Controls for Entity 0
  *
@@ -167,7 +183,9 @@ struct sdca_entity {
 /**
  * struct sdca_function_data - top-level information for one SDCA function
  * @desc: Pointer to short descriptor from initial parsing.
+ * @init_table: Pointer to a table of initialization writes.
  * @entities: Dynamically allocated array of Entities.
+ * @num_init_table: Number of initialization writes.
  * @num_entities: Number of Entities reported in this Function.
  * @busy_max_delay: Maximum Function busy delay in microseconds, before an
  * error should be reported.
@@ -175,7 +193,9 @@ struct sdca_entity {
 struct sdca_function_data {
        struct sdca_function_desc *desc;
 
+       struct sdca_init_write *init_table;
        struct sdca_entity *entities;
+       int num_init_table;
        int num_entities;
 
        unsigned int busy_max_delay;

diff --git a/sound/soc/sdca/sdca_functions.c b/sound/soc/sdca/sdca_functions.c
index 72b82280918d7ce9b89f6fa993f51a14474c49dc..f914ec3f86c9ac794b722caffabce26343762e79 100644 (file)
--- a/sound/soc/sdca/sdca_functions.c
+++ b/sound/soc/sdca/sdca_functions.c
@@ -9,6 +9,7 @@
 #define dev_fmt(fmt) "%s: " fmt, __func__
 
 #include <linux/acpi.h>
+#include <linux/byteorder/generic.h>
 #include <linux/device.h>
 #include <linux/dev_printk.h>
 #include <linux/module.h>
@@ -185,6 +186,62 @@ void sdca_lookup_functions(struct sdw_slave *slave)
 }
 EXPORT_SYMBOL_NS(sdca_lookup_functions, "SND_SOC_SDCA");
 
+static int find_sdca_init_table(struct device *dev,
+                               struct fwnode_handle *function_node,
+                               struct sdca_function_data *function)
+{
+       struct sdca_init_write *init_write;
+       int write_size = sizeof(init_write->addr) + sizeof(init_write->val);
+       u8 *init_list, *init_iter;
+       int num_init_writes;
+
+       num_init_writes = fwnode_property_count_u8(function_node,
+                                                  "mipi-sdca-function-initialization-table");
+       if (!num_init_writes || num_init_writes == -EINVAL) {
+               return 0;
+       } else if (num_init_writes < 0) {
+               dev_err(dev, "%pfwP: failed to read initialization table: %d\n",
+                       function_node, num_init_writes);
+               return num_init_writes;
+       } else if (num_init_writes % write_size != 0) {
+               dev_err(dev, "%pfwP: init table size invalid\n", function_node);
+               return -EINVAL;
+       } else if (num_init_writes > SDCA_MAX_INIT_COUNT) {
+               dev_err(dev, "%pfwP: maximum init table size exceeded\n", function_node);
+               return -EINVAL;
+       }
+
+       init_write = devm_kcalloc(dev, num_init_writes / write_size,
+                                 sizeof(*init_write), GFP_KERNEL);
+       if (!init_write)
+               return -ENOMEM;
+
+       init_list = kcalloc(num_init_writes, sizeof(*init_list), GFP_KERNEL);
+       if (!init_list)
+               return -ENOMEM;
+
+       fwnode_property_read_u8_array(function_node,
+                                     "mipi-sdca-function-initialization-table",
+                                     init_list, num_init_writes);
+
+       function->num_init_table = num_init_writes;
+       function->init_table = init_write;
+
+       for (init_iter = init_list; init_iter < init_list + num_init_writes;) {
+               u32 *addr = (u32 *)init_iter;
+
+               init_write->addr = le32_to_cpu(*addr);
+               init_iter += sizeof(init_write->addr);
+
+               init_write->val = *init_iter;
+               init_iter += sizeof(init_write->val);
+       }
+
+       kfree(init_list);
+
+       return 0;
+}
+
 static int find_sdca_entity(struct device *dev,
                            struct fwnode_handle *function_node,
                            struct fwnode_handle *entity_node,
@@ -435,6 +492,10 @@ int sdca_parse_function(struct device *dev,
        dev_info(dev, "%pfwP: name %s delay %dus\n", function->desc->node,
                 function->desc->name, function->busy_max_delay);
 
+       ret = find_sdca_init_table(dev, function_desc->node, function);
+       if (ret)
+               return ret;
+
        ret = find_sdca_entities(dev, function_desc->node, function);
        if (ret)
                return ret;