Fix default DMIC gain on AMD PDM drivers

Merge series from Mario Limonciello <mario.limonciello@amd.com>:

It's been reported that a number of laptops have a low volume
level from the digital microphone compared to Windows.

AMD offers a register that can adjust the gain for PDM which is not
configured at maximum gain by default.

To fix this change the default for all 3 drivers to raise the gain
but also offer a module parameter. The module parameter can be used
for debugging if the gain is too high on a given laptop.

This is intentionally split into multiple patches for default and
parameter so that if the default really does behave better universally
we can bring it back to stable too later.

sound/soc/amd/ps/acp63.h

@@ -29,7 +29,7 @@
 #define ACP_ERROR_STAT	29
 #define PDM_DECIMATION_FACTOR	2
 #define ACP_PDM_CLK_FREQ_MASK	7
-#define ACP_WOV_MISC_CTRL_MASK	0x10
+#define ACP_WOV_GAIN_CONTROL	GENMASK(4, 3)
 #define ACP_PDM_ENABLE		1
 #define ACP_PDM_DISABLE		0
 #define ACP_PDM_DMA_EN_STATUS	2

sound/soc/amd/ps/ps-pdm-dma.c

@@ -7,6 +7,7 @@
 
 #include <linux/platform_device.h>
 #include <linux/module.h>
+#include <linux/bitfield.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <sound/pcm_params.h>
@@ -18,6 +19,10 @@
 
 #define DRV_NAME "acp_ps_pdm_dma"
 
+static int pdm_gain = 3;
+module_param(pdm_gain, int, 0644);
+MODULE_PARM_DESC(pdm_gain, "Gain control (0-3)");
+
 static const struct snd_pcm_hardware acp63_pdm_hardware_capture = {
 	.info = SNDRV_PCM_INFO_INTERLEAVED |
 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
@@ -55,7 +60,8 @@ static void acp63_enable_pdm_clock(void __iomem *acp_base)
 
 	acp63_writel(pdm_clk_enable, acp_base + ACP_WOV_CLK_CTRL);
 	pdm_ctrl = acp63_readl(acp_base + ACP_WOV_MISC_CTRL);
-	pdm_ctrl |= ACP_WOV_MISC_CTRL_MASK;
+	pdm_ctrl &= ~ACP_WOV_GAIN_CONTROL;
+	pdm_ctrl |= FIELD_PREP(ACP_WOV_GAIN_CONTROL, clamp(pdm_gain, 0, 3));
 	acp63_writel(pdm_ctrl, acp_base + ACP_WOV_MISC_CTRL);
 }
 

sound/soc/amd/renoir/acp3x-pdm-dma.c

@@ -6,6 +6,7 @@
 
 #include <linux/platform_device.h>
 #include <linux/module.h>
+#include <linux/bitfield.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/pm_runtime.h>
@@ -17,6 +18,10 @@
 
 #define DRV_NAME "acp_rn_pdm_dma"
 
+static int pdm_gain = 3;
+module_param(pdm_gain, int, 0644);
+MODULE_PARM_DESC(pdm_gain, "Gain control (0-3)");
+
 static const struct snd_pcm_hardware acp_pdm_hardware_capture = {
 	.info = SNDRV_PCM_INFO_INTERLEAVED |
 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
@@ -80,7 +85,8 @@ static void enable_pdm_clock(void __iomem *acp_base)
 
 	rn_writel(pdm_clk_enable, acp_base + ACP_WOV_CLK_CTRL);
 	pdm_ctrl = rn_readl(acp_base + ACP_WOV_MISC_CTRL);
-	pdm_ctrl |= ACP_WOV_MISC_CTRL_MASK;
+	pdm_ctrl &= ~ACP_WOV_GAIN_CONTROL;
+	pdm_ctrl |= FIELD_PREP(ACP_WOV_GAIN_CONTROL, clamp(pdm_gain, 0, 3));
 	rn_writel(pdm_ctrl, acp_base + ACP_WOV_MISC_CTRL);
 }
 

sound/soc/amd/renoir/rn_acp3x.h

@@ -34,7 +34,7 @@
 #define ACP_ERROR_STAT 29
 #define PDM_DECIMATION_FACTOR 0x2
 #define ACP_PDM_CLK_FREQ_MASK 0x07
-#define ACP_WOV_MISC_CTRL_MASK 0x10
+#define ACP_WOV_GAIN_CONTROL	GENMASK(4, 3)
 #define ACP_PDM_ENABLE 0x01
 #define ACP_PDM_DISABLE 0x00
 #define ACP_PDM_DMA_EN_STATUS 0x02

sound/soc/amd/yc/acp6x-pdm-dma.c

@@ -7,6 +7,7 @@
 
 #include <linux/platform_device.h>
 #include <linux/module.h>
+#include <linux/bitfield.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <sound/pcm_params.h>
@@ -18,6 +19,10 @@
 
 #define DRV_NAME "acp_yc_pdm_dma"
 
+static int pdm_gain = 3;
+module_param(pdm_gain, int, 0644);
+MODULE_PARM_DESC(pdm_gain, "Gain control (0-3)");
+
 static const struct snd_pcm_hardware acp6x_pdm_hardware_capture = {
 	.info = SNDRV_PCM_INFO_INTERLEAVED |
 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
@@ -55,7 +60,8 @@ static void acp6x_enable_pdm_clock(void __iomem *acp_base)
 
 	acp6x_writel(pdm_clk_enable, acp_base + ACP_WOV_CLK_CTRL);
 	pdm_ctrl = acp6x_readl(acp_base + ACP_WOV_MISC_CTRL);
-	pdm_ctrl |= ACP_WOV_MISC_CTRL_MASK;
+	pdm_ctrl &= ~ACP_WOV_GAIN_CONTROL;
+	pdm_ctrl |= FIELD_PREP(ACP_WOV_GAIN_CONTROL, clamp(pdm_gain, 0, 3));
 	acp6x_writel(pdm_ctrl, acp_base + ACP_WOV_MISC_CTRL);
 }
 

sound/soc/amd/yc/acp6x.h

@@ -31,7 +31,7 @@
 #define ACP_ERROR_STAT	29
 #define PDM_DECIMATION_FACTOR	2
 #define ACP_PDM_CLK_FREQ_MASK	7
-#define ACP_WOV_MISC_CTRL_MASK	0x10
+#define ACP_WOV_GAIN_CONTROL	GENMASK(4, 3)
 #define ACP_PDM_ENABLE		1
 #define ACP_PDM_DISABLE		0
 #define ACP_PDM_DMA_EN_STATUS	2