Add a wrapper function to read the _SUB string from ACPI.

Signed-off-by: Stefan Binding sbinding@opensource.cirrus.com --- drivers/acpi/utils.c | 26 ++++++++++++++++++++++++++ include/linux/acpi.h | 8 ++++++++ 2 files changed, 34 insertions(+)

diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c index 3a9773a09e19..5d1bdb79e372 100644 --- a/drivers/acpi/utils.c +++ b/drivers/acpi/utils.c @@ -291,6 +291,32 @@ int acpi_get_local_address(acpi_handle handle, u32 *addr) } EXPORT_SYMBOL(acpi_get_local_address);

+int acpi_get_sub(acpi_handle handle, char *sub, size_t size) +{ + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + union acpi_object *obj; + acpi_status status; + int ret; + + status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer); + if (!ACPI_SUCCESS(status)) { + acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status); + return -ENOENT; + } + + obj = buffer.pointer; + if (obj->type == ACPI_TYPE_STRING) { + ret = strscpy(sub, obj->string.pointer, size); + } else { + acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n"); + ret = -EINVAL; + } + acpi_os_free(buffer.pointer); + + return ret; +} +EXPORT_SYMBOL_GPL(acpi_get_sub); + acpi_status acpi_evaluate_reference(acpi_handle handle, acpi_string pathname, diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 4f82a5bc6d98..9bf18adf5920 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -21,6 +21,8 @@ #endif #include <acpi/acpi.h>

+#define ACPI_MAX_SUB_BUF_SIZE 9 + #ifdef CONFIG_ACPI

#include <linux/list.h> @@ -762,6 +764,7 @@ static inline u64 acpi_arch_get_root_pointer(void) #endif

int acpi_get_local_address(acpi_handle handle, u32 *addr); +int acpi_get_sub(acpi_handle handle, char *sub, size_t size);

#else /* !CONFIG_ACPI */

@@ -1023,6 +1026,11 @@ static inline int acpi_get_local_address(acpi_handle handle, u32 *addr) return -ENODEV; }

+static int acpi_get_sub(acpi_handle handle, char *sub, size_t size) +{ + return -ENODEV; +} + static inline int acpi_register_wakeup_handler(int wake_irq, bool (*wakeup)(void *context), void *context) {

When loading firmware, wm_adsp uses a number of parameters to determine the path of the firmware and tuning files to load. One of these parameters is system_name. Add support in cs35l41 to read this system name from the ACPI _SUB ID in order to uniquely identify the firmware and tuning mapped to a particular system.

Signed-off-by: Stefan Binding sbinding@opensource.cirrus.com --- sound/soc/codecs/cs35l41.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)

diff --git a/sound/soc/codecs/cs35l41.c b/sound/soc/codecs/cs35l41.c index 8766e19d85f1..5df04a2ab5a3 100644 --- a/sound/soc/codecs/cs35l41.c +++ b/sound/soc/codecs/cs35l41.c @@ -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 +1143,28 @@ static int cs35l41_dsp_init(struct cs35l41_private *cs35l41) return ret; }

+static int cs35l41_probe_acpi(struct cs35l41_private *cs35l41) +{ + struct acpi_device *adev; + int ret; + char sub[ACPI_MAX_SUB_BUF_SIZE]; + + adev = ACPI_COMPANION(cs35l41->dev); + /* If there is no ACPI_COMPANION, there is no ACPI for this system, return 0 */ + if (!adev) + return 0; + + ret = acpi_get_sub(adev->handle, sub, sizeof(sub)); + if (ret < 0) + return ret; + + cs35l41->dsp.system_name = devm_kstrdup(cs35l41->dev, sub, GFP_KERNEL); + if (!cs35l41->dsp.system_name) + return -ENOMEM; + + 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 +1293,10 @@ int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg * goto err; }

+ ret = cs35l41_probe_acpi(cs35l41); + if (ret < 0) + goto err; + ret = cs35l41_dsp_init(cs35l41); if (ret < 0) goto err;