ALSA: hda: cs35l41: Read Speaker Calibration data from UEFI variables

Speaker Calibration data, specific to an individual speaker is
stored inside UEFI variables during calibration, and can be
used by the DSP.
Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Signed-off-by: Vitaly Rodionov <vitalyr@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20220630002335.366545-11-vitalyr@opensource.cirrus.comSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/cs35l41_hda.c

@@ -26,6 +26,12 @@
 #define HALO_STATE_DSP_CTL_NAME		"HALO_STATE"
 #define HALO_STATE_DSP_CTL_TYPE		5
 #define HALO_STATE_DSP_CTL_ALG		262308
+#define CAL_R_DSP_CTL_NAME		"CAL_R"
+#define CAL_STATUS_DSP_CTL_NAME		"CAL_STATUS"
+#define CAL_CHECKSUM_DSP_CTL_NAME	"CAL_CHECKSUM"
+#define CAL_AMBIENT_DSP_CTL_NAME	"CAL_AMBIENT"
+#define CAL_DSP_CTL_TYPE		5
+#define CAL_DSP_CTL_ALG			205
 
 static const struct reg_sequence cs35l41_hda_config[] = {
 	{ CS35L41_PLL_CLK_CTRL,		0x00000430 }, // 3072000Hz, BCLK Input, PLL_REFCLK_EN = 1
@@ -282,6 +288,96 @@ static int cs35l41_request_firmware_files(struct cs35l41_hda *cs35l41,
 	return ret;
 }
 
+#if IS_ENABLED(CONFIG_EFI)
+static int cs35l41_apply_calibration(struct cs35l41_hda *cs35l41, unsigned int ambient,
+				     unsigned int r0, unsigned int status, unsigned int checksum)
+{
+	int ret;
+
+	ret = hda_cs_dsp_write_ctl(&cs35l41->cs_dsp, CAL_AMBIENT_DSP_CTL_NAME, CAL_DSP_CTL_TYPE,
+				   CAL_DSP_CTL_ALG, &ambient, 4);
+	if (ret) {
+		dev_err(cs35l41->dev, "Cannot Write Control: %s - %d\n", CAL_AMBIENT_DSP_CTL_NAME,
+			ret);
+		return ret;
+	}
+	ret = hda_cs_dsp_write_ctl(&cs35l41->cs_dsp, CAL_R_DSP_CTL_NAME, CAL_DSP_CTL_TYPE,
+				   CAL_DSP_CTL_ALG, &r0, 4);
+	if (ret) {
+		dev_err(cs35l41->dev, "Cannot Write Control: %s - %d\n", CAL_R_DSP_CTL_NAME, ret);
+		return ret;
+	}
+	ret = hda_cs_dsp_write_ctl(&cs35l41->cs_dsp, CAL_STATUS_DSP_CTL_NAME, CAL_DSP_CTL_TYPE,
+				   CAL_DSP_CTL_ALG, &status, 4);
+	if (ret) {
+		dev_err(cs35l41->dev, "Cannot Write Control: %s - %d\n", CAL_STATUS_DSP_CTL_NAME,
+			ret);
+		return ret;
+	}
+	ret = hda_cs_dsp_write_ctl(&cs35l41->cs_dsp, CAL_CHECKSUM_DSP_CTL_NAME, CAL_DSP_CTL_TYPE,
+				   CAL_DSP_CTL_ALG, &checksum, 4);
+	if (ret) {
+		dev_err(cs35l41->dev, "Cannot Write Control: %s - %d\n", CAL_CHECKSUM_DSP_CTL_NAME,
+			ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int cs35l41_save_calibration(struct cs35l41_hda *cs35l41)
+{
+	static efi_guid_t efi_guid = EFI_GUID(0x02f9af02, 0x7734, 0x4233, 0xb4, 0x3d, 0x93, 0xfe,
+					      0x5a, 0xa3, 0x5d, 0xb3);
+	static efi_char16_t efi_name[] = L"CirrusSmartAmpCalibrationData";
+	const struct cs35l41_amp_efi_data *efi_data;
+	const struct cs35l41_amp_cal_data *cl;
+	unsigned long data_size = 0;
+	efi_status_t status;
+	int ret = 0;
+	u8 *data = NULL;
+	u32 attr;
+
+	/* Get real size of UEFI variable */
+	status = efi.get_variable(efi_name, &efi_guid, &attr, &data_size, data);
+	if (status == EFI_BUFFER_TOO_SMALL) {
+		ret = -ENODEV;
+		/* Allocate data buffer of data_size bytes */
+		data = vmalloc(data_size);
+		if (!data)
+			return -ENOMEM;
+		/* Get variable contents into buffer */
+		status = efi.get_variable(efi_name, &efi_guid, &attr, &data_size, data);
+		if (status == EFI_SUCCESS) {
+			efi_data = (struct cs35l41_amp_efi_data *)data;
+			dev_dbg(cs35l41->dev, "Calibration: Size=%d, Amp Count=%d\n",
+				efi_data->size, efi_data->count);
+			if (efi_data->count > cs35l41->index) {
+				cl = &efi_data->data[cs35l41->index];
+				dev_dbg(cs35l41->dev,
+					"Calibration: Ambient=%02x, Status=%02x, R0=%d\n",
+					cl->calAmbient, cl->calStatus, cl->calR);
+
+				/* Calibration can only be applied whilst the DSP is not running */
+				ret = cs35l41_apply_calibration(cs35l41,
+								cpu_to_be32(cl->calAmbient),
+								cpu_to_be32(cl->calR),
+								cpu_to_be32(cl->calStatus),
+								cpu_to_be32(cl->calR + 1));
+			}
+		}
+		vfree(data);
+	}
+	return ret;
+}
+#else
+static int cs35l41_save_calibration(struct cs35l41_hda *cs35l41)
+{
+	dev_warn(cs35l41->dev, "Calibration not supported without EFI support.\n");
+	return 0;
+}
+#endif
+
 static int cs35l41_init_dsp(struct cs35l41_hda *cs35l41)
 {
 	const struct firmware *coeff_firmware = NULL;
@@ -314,7 +410,12 @@ static int cs35l41_init_dsp(struct cs35l41_hda *cs35l41)
 
 	ret = cs_dsp_power_up(dsp, wmfw_firmware, wmfw_filename, coeff_firmware, coeff_filename,
 			      FW_NAME);
+	if (ret)
+		goto err_release;
+
+	ret = cs35l41_save_calibration(cs35l41);
 
+err_release:
 	release_firmware(wmfw_firmware);
 	release_firmware(coeff_firmware);
 	kfree(wmfw_filename);

sound/pci/hda/cs35l41_hda.h

@@ -10,6 +10,7 @@
 #ifndef __CS35L41_HDA_H__
 #define __CS35L41_HDA_H__
 
+#include <linux/efi.h>
 #include <linux/regulator/consumer.h>
 #include <linux/gpio/consumer.h>
 #include <linux/device.h>
@@ -18,6 +19,20 @@
 #include <linux/firmware/cirrus/cs_dsp.h>
 #include <linux/firmware/cirrus/wmfw.h>
 
+struct cs35l41_amp_cal_data {
+	u32 calTarget[2];
+	u32 calTime[2];
+	s8 calAmbient;
+	u8 calStatus;
+	u16 calR;
+} __packed;
+
+struct cs35l41_amp_efi_data {
+	u32 size;
+	u32 count;
+	struct cs35l41_amp_cal_data data[];
+} __packed;
+
 enum cs35l41_hda_spk_pos {
 	CS35l41_LEFT,
 	CS35l41_RIGHT,