[PATCH 1/3] ALSA: hda/tegra: correct number of SDO lines for Tegra194

[Sameer Pujar <spujar@nvidia.com>]

Tegra194 supports 4 SDO lines but GCAP register indicates 2 lines. Thus it
does not reflect the true capability of the HW. This patch presents a
workaround by updating NSDO value accordingly in T_AZA_DBG_CFG_2 register.

Signed-off-by: Sameer Pujar <spujar@nvidia.com>
---
 sound/pci/hda/hda_tegra.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c
index 773992a..45dc544 100644
--- a/sound/pci/hda/hda_tegra.c
+++ b/sound/pci/hda/hda_tegra.c
@@ -52,10 +52,21 @@
 #define HDA_IPFS_INTR_MASK        0x188
 #define HDA_IPFS_EN_INTR          (1 << 16)
 
+/* FPCI */
+#define FPCI_DBG_CFG_2		  0x10F4
+#define FPCI_GCAP_NSDO_SHIFT	  18
+#define FPCI_GCAP_NSDO_MASK	  (0x3 << FPCI_GCAP_NSDO_SHIFT)
+
 /* max number of SDs */
 #define NUM_CAPTURE_SD 1
 #define NUM_PLAYBACK_SD 1
 
+/*
+ * Tegra194 does not reflect correct number of SDO lines. Below macro
+ * is used to update the GCAP register to workaround the issue.
+ */
+#define TEGRA194_NUM_SDO_LINES	  4
+
 struct hda_tegra {
 	struct azx chip;
 	struct device *dev;
@@ -275,6 +286,7 @@ static int hda_tegra_init_clk(struct hda_tegra *hda)
 
 static int hda_tegra_first_init(struct azx *chip, struct platform_device *pdev)
 {
+	struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip);
 	struct hdac_bus *bus = azx_bus(chip);
 	struct snd_card *card = chip->card;
 	int err;
@@ -298,6 +310,26 @@ static int hda_tegra_first_init(struct azx *chip, struct platform_device *pdev)
 	bus->irq = irq_id;
 	card->sync_irq = bus->irq;
 
+	/*
+	 * Tegra194 has 4 SDO lines and the STRIPE can be used to
+	 * indicate how many of the SDO lines the stream should be
+	 * striped. But GCAP register does not reflect the true
+	 * capability of HW. Below workaround helps to fix this.
+	 *
+	 * GCAP_NSDO is bits 19:18 in T_AZA_DBG_CFG_2,
+	 * 0 for 1 SDO, 1 for 2 SDO, 2 for 4 SDO lines.
+	 */
+	if (of_device_is_compatible(np, "nvidia,tegra194-hda")) {
+		u32 val;
+
+		dev_info(card->dev, "Override SDO lines to %u\n",
+			 TEGRA194_NUM_SDO_LINES);
+
+		val = readl(hda->regs + FPCI_DBG_CFG_2) & ~FPCI_GCAP_NSDO_MASK;
+		val |= (TEGRA194_NUM_SDO_LINES >> 1) << FPCI_GCAP_NSDO_SHIFT;
+		writel(val, hda->regs + FPCI_DBG_CFG_2);
+	}
+
 	gcap = azx_readw(chip, GCAP);
 	dev_dbg(card->dev, "chipset global capabilities = 0x%x\n", gcap);
 
@@ -408,6 +440,7 @@ static int hda_tegra_create(struct snd_card *card,
 
 static const struct of_device_id hda_tegra_match[] = {
 	{ .compatible = "nvidia,tegra30-hda" },
+	{ .compatible = "nvidia,tegra194-hda" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, hda_tegra_match);
-- 
2.7.4