Unverified Commit 1c69bbc3 authored by Mark Brown's avatar Mark Brown
Browse files

Read _SUB from ACPI to be able to identify firmware 

Merge series from Stefan Binding <sbinding@opensource.cirrus.com>:

CS35L41 has a DSP which is able to run firmware, as well as a tuning file.
Different systems may want to use different firmwares and tuning files, and
some firmwares/tunings may not be compatible with other systems.
To allow a system to select the correct fimware/tuning, we can read an _SUB
from the ACPI. This _SUB can then be used to uniquely identify the system
in the firmware/tuning file name.

Add a helper function which reads the _SUB, so this can be used by other
parts in the future.
Add support inside the CS35L41 ASoC driver to read this _SUB, and save it
appropriately.
parents e1d1ffed c1ad1388

drivers/acpi/utils.c

+38 −0
Original line number Diff line number Diff line
@@ -291,6 +291,44 @@ int acpi_get_local_address(acpi_handle handle, u32 *addr) 
}

EXPORT_SYMBOL(acpi_get_local_address);



#define ACPI_MAX_SUB_BUF_SIZE	9



const char *acpi_get_subsystem_id(acpi_handle handle)

{

	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	union acpi_object *obj;

	acpi_status status;

	const char *sub;

	size_t len;



	status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer);

	if (ACPI_FAILURE(status)) {

		acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);

		return ERR_PTR(-ENODATA);

	}



	obj = buffer.pointer;

	if (obj->type == ACPI_TYPE_STRING) {

		len = strlen(obj->string.pointer);

		if (len < ACPI_MAX_SUB_BUF_SIZE && len > 0) {

			sub = kstrdup(obj->string.pointer, GFP_KERNEL);

			if (!sub)

				sub = ERR_PTR(-ENOMEM);

		} else {

			acpi_handle_err(handle, "ACPI _SUB Length %zu is Invalid\n", len);

			sub = ERR_PTR(-ENODATA);

		}

	} else {

		acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");

		sub = ERR_PTR(-ENODATA);

	}



	acpi_os_free(buffer.pointer);



	return sub;

}

EXPORT_SYMBOL_GPL(acpi_get_subsystem_id);



acpi_status

acpi_evaluate_reference(acpi_handle handle,

			acpi_string pathname,

include/linux/acpi.h

+6 −0
Original line number Diff line number Diff line
@@ -762,6 +762,7 @@ static inline u64 acpi_arch_get_root_pointer(void) 
#endif



int acpi_get_local_address(acpi_handle handle, u32 *addr);

const char *acpi_get_subsystem_id(acpi_handle handle);



#else	/* !CONFIG_ACPI */
@@ -1023,6 +1024,11 @@ static inline int acpi_get_local_address(acpi_handle handle, u32 *addr) 
	return -ENODEV;

}



static inline const char *acpi_get_subsystem_id(acpi_handle handle)

{

	return ERR_PTR(-ENODEV);

}



static inline int acpi_register_wakeup_handler(int wake_irq,

	bool (*wakeup)(void *context), void *context)

{

sound/soc/codecs/cs35l41.c

+30 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
//

// Author: David Rhodes <david.rhodes@cirrus.com>



#include <linux/acpi.h>

#include <linux/delay.h>

#include <linux/err.h>

#include <linux/init.h>
@@ -1142,6 +1143,30 @@ static int cs35l41_dsp_init(struct cs35l41_private *cs35l41) 
	return ret;

}



static int cs35l41_acpi_get_name(struct cs35l41_private *cs35l41)

{

	acpi_handle handle = ACPI_HANDLE(cs35l41->dev);

	const char *sub;



	/* If there is no ACPI_HANDLE, there is no ACPI for this system, return 0 */

	if (!handle)

		return 0;



	sub = acpi_get_subsystem_id(handle);

	if (IS_ERR(sub)) {

		/* If bad ACPI, return 0 and fallback to legacy firmware path, otherwise fail */

		if (PTR_ERR(sub) == -ENODATA)

			return 0;

		else

			return PTR_ERR(sub);

	}



	cs35l41->dsp.system_name = sub;

	dev_dbg(cs35l41->dev, "Subsystem ID: %s\n", cs35l41->dsp.system_name);



	return 0;

}



int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg *hw_cfg)

{

	u32 regid, reg_revid, i, mtl_revid, int_status, chipid_match;
@@ -1270,6 +1295,10 @@ int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg * 
		goto err;

	}



	ret = cs35l41_acpi_get_name(cs35l41);

	if (ret < 0)

		goto err;



	ret = cs35l41_dsp_init(cs35l41);

	if (ret < 0)

		goto err;
@@ -1316,6 +1345,7 @@ void cs35l41_remove(struct cs35l41_private *cs35l41) 
	pm_runtime_disable(cs35l41->dev);



	regmap_write(cs35l41->regmap, CS35L41_IRQ1_MASK1, 0xFFFFFFFF);

	kfree(cs35l41->dsp.system_name);

	wm_adsp2_remove(&cs35l41->dsp);

	cs35l41_safe_reset(cs35l41->regmap, cs35l41->hw_cfg.bst_type);